Description:FIELD
The present disclosure relates to the field of batteries. Particularly, the present disclosure relates to a process for the preparation of a positive electrode.
DEFINITIONS
As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used, indicate otherwise.
Reduced graphene: The term “reduced graphene” refers to a partially restored form of graphene obtained by reducing graphene oxide, characterized by a layered carbon structure with residual oxygen groups and moderate electrical conductivity.
Spinel Oxide: The term “spinel oxide” refers to a class of metal oxides with a general AB₂O₄ chemical formula. Their crystal structure allows for modification of their electronic, chemical, and magnetic properties, leading to diverse applications.
Conductivity: The term “conductivity” refers to the ability of a material to conduct electric current. It measures how easily electrons can flow through a material.
Peel strength: The term “peel strength” refers to the force required to peel or detach an electrode coating (active material layer) from a current collector (cathodes and anodes).
Through Plane Resistance: The term “through plane resistance” refers to the opposition to the flow/ movement of electric current perpendicular to the flat plane of a material.
Calendaring: The term “calendaring” refers to a mechanical compression process used in battery electrode manufacturing, wherein a dried electrode sheet is passed through a set of heated, pressure-controlled rollers to reduce its thickness, increase density, and improve uniformity.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
Dry electrode manufacturing is an emerging technique in lithium-ion battery production, where the electrode components are processed without the use of solvents. Instead of forming a slurry, the materials are dry-mixed and mechanically pressed onto the current collector.
One of the challenges in dry electrode processing is maintaining a balance between mechanical integrity, electrical conductivity and high electrode density. In the conventional slurry-based processes, the solvents aids in the dispersion of the components such as active materials, binders, conductive additives and the like. However, dry mixing relies solely on mechanical blending, which limits the ability to achieve a uniform distribution of the components.
Conventionally used conductive carbon systems, composed of materials such as carbon black, graphite and the like tend to agglomerate during dry mixing and hence fail to achieve a uniform distribution. As a result, the conductive network formed is non-uniform and discontinuous, leading to poor electrical connectivity across the electrode.
Further, these conventional carbon systems do not contribute significantly to the mechanical reinforcement of the electrode resulting in increased risk of particle detachment, cracking, and delamination from the current collector during manufacturing steps such as calendaring, cycling, handling and the like. This results in low peel strength of the electrodes.
Furthermore, when the conductive pathways are non-uniform and the structure lacks support, the electrode cannot be packed efficiently. Although high packing density helps increase energy stored in a given volume, it should not reduce ion movement or weaken the electrode. If the electrode is packed too loosely, it limits the amount of active material that can be used. On the other hand, pressing a weak structure too much can damage it, leading to poor performance during repeated charging and discharging
Still further, the uneven distribution of conductive pathways and lack of structural reinforcement negatively impact the electrode packing density. Though high density is desirable for increasing volumetric energy density, it should block ion transport pathways and mechanical strength. Electrodes with low density limits the active material per unit volume, while over-compression of a weak structure degrades performance over repeated charge–discharge cycles.
The aforestated drawbacks lead to a decline in battery performance, such as reduced rate capability because of poor electrical conductivity, shorter cycle life resulting from mechanical damage and isolation of active materials, heightened safety and reliability risks due to delamination or the formation of hot spots, challenges in manufacturing caused by inconsistent coating quality and overall performance and the like.
Thus, there is felt a need to provide a process for the preparation of an electrode that mitigates the drawbacks mentioned herein above or at least provides an alternate solution.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows.
It is an object of the present disclosure is to ameliorate one or more problems given in the background or to at least provide a useful alternative.
An object of the present disclosure is to provide a process for the preparation of a positive electrode.
Another object of the present disclosure is to provide a process for the preparation of a positive electrode that is simple, economic and scalable.
Still another object of the present disclosure is to provide a positive electrode that has improved peel strength and electrical conductivity.
Yet another object of the present disclosure is to provide a positive electrode with improved mechanical strength, and density.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
In an aspect of the present disclosure, there is provided a process for the preparation of a positive electrode. The process comprises the following steps:
i. mixing a predetermined amount of an active material, a predetermined amount of a first portion of a first conductive agent and a predetermined amount of a second conductive agent under stirring at a first predetermined speed and at a first predetermined temperature for a first predetermined time period to obtain a first mixture;
ii. adding a predetermined amount of a first binder to the first mixture under stirring at a second predetermined speed and at a second predetermined temperature for a second predetermined time period to obtain a second mixture;
iii. adding a predetermined amount of a second portion of the first conductive agent to the second mixture under stirring at a third predetermined speed and at a third predetermined temperature for a third predetermined time period to obtain a third mixture;
iv. adding a predetermined amount of a second binder to the third mixture under stirring at a fourth predetermined speed and at a fourth predetermined temperature for a fourth predetermined time period to obtain a fourth mixture;
v. adding a predetermined amount of a third conductive agent to the fourth mixture under at a fifth predetermined speed and at a fifth predetermined temperature for a fifth predetermined time period to obtain a fifth mixture;
vi. mixing the fifth mixture under stirring at a sixth predetermined speed and at a sixth predetermined temperature for a sixth predetermined time period to obtain a resultant mixture; and
vii. cooling the resultant mixture to a seventh predetermined temperature by reducing the sixth predetermined speed to a seventh predetermined speed to obtain the positive electrode.
In an embodiment of the present disclosure, the active material is a layered transition metal oxide, wherein the layered transition metal oxide is selected from the group consisting of lithium nickel manganese cobalt oxide, lithium-rich transition metal oxide and spinel oxide.
In an embodiment of the present disclosure, the first conductive agent is selected from the group consisting of carbon black, high surface area carbon and carbon nanofibers.
In an embodiment of the present disclosure, the second conductive agent is selected from the group consisting of natural graphite, synthetic graphite, and carbon nanotube (CNT).
In an embodiment of the present disclosure, the third conductive agent is selected from graphene and reduced graphene.
In an embodiment of the present disclosure, the first binder is selected from the group consisting of polyvinylidene fluoride (PVDF), vinylidene fluoride (VDF) and polyvinylidene fluoride (PVDF)-copolymer.
In an embodiment of the present disclosure, the second binder is selected from polytetrafluoroethylene (PTFE) and polytetrafluoroethylene (PTFE)-copolymer.
In an embodiment of the present disclosure,
• the predetermined amount of the active material is in the range of 94 mass% to 98 mass% with respect to the total mass of the positive electrode;
• the predetermined amount of said first conductive agent is in the range of 0.5 mass% to 2 mass% with respect to the total mass of the positive electrode;
• the predetermined amount of the second conductive agent is in the range of 0.1 mass% to 0.5 mass% with respect to the total mass of the positive electrode;
• the predetermined amount of the third conductive agent is in the range of 0.25 mass% to 0.5 mass% with respect to the total mass of the positive electrode;
• the predetermined amount of the first binder is in the range of 0.5 mass% to 1.5 mass% with respect to the total mass of the positive electrode; and
• the predetermined amount of the second binder is in the range of 0.5 mass% to 1.5 mass% with respect to the total mass of the positive electrode.
In an embodiment of the present disclosure,
• the predetermined amount of the first portion of the first conductive agent is in the range of 60 mass% to 70 mass% with respect to the total mass of the first conductive agent; and
• the predetermined amount of the second portion of the first conductive agent is in the range of 30 mass% to 40 mass% with respect to the total mass of the first conductive agent.
In an embodiment of the present disclosure,
• the first predetermined speed is in the range of 2500 rpm to 3500 rpm;
• the second predetermined speed, the third predetermined speed, the fourth predetermined speed and the fifth predetermined speed are independently in the range of 1000 rpm to 2000 rpm;
• the sixth predetermined speed is in the range of 2500 rpm to 3500 rpm; and
• the seventh predetermined speed is in the range of 400 rpm to 700 rpm.
In an embodiment of the present disclosure,
• the first predetermined temperature is in the range of 15 °C to 25 °C;
• the second predetermined temperature, the third predetermined temperature, the fourth predetermined temperature, the fifth predetermined temperature and the seventh predetermined temperature are independently in the range of 10 °C to 19 °C; and
• the sixth predetermined temperature is in the range of 70 °C to 90 °C.
In an embodiment of the present disclosure,
• the first predetermined time period is in the range of 60 minutes to 120 minutes;
• the second predetermined time period and the fourth predetermined time period are independently in the range of 5 minutes to 25 minutes;
• the third predetermined time period and said fifth predetermined time period are independently in the range of 20 minutes to 40 minutes; and
• the sixth predetermined time period is in the range of 15 minutes to 25 minutes.
In an embodiment of the present disclosure, the positive electrode is calendared to achieve a density in the range of 3.45 g/cc to 3.85 g/cc.
In another aspect of the present disclosure, there is provided a positive electrode comprising
• a predetermined amount of an active material;
• a predetermined amount of a first conductive agent;
• a predetermined amount of a second conductive agent;
• a predetermined amount of a third conductive agent;
• a predetermined amount of a first binder; and
• a predetermined amount of a second binder.
In an embodiment of the present disclosure,
• the active material is a layered transition metal oxide, wherein said layered transition metal oxide is selected from the group consisting of lithium nickel manganese cobalt oxide, lithium-rich transition metal oxide and spinel oxide;
• the first conductive agent is selected from the group consisting of carbon black, high surface area carbon and carbon nanofibers;
• the second conductive agent is selected from the group consisting of natural graphite, synthetic graphite and carbon nanotube (CNT);
• the third conductive layer is selected from graphene and reduced graphene;
• the first binder is selected from the group consisting of polyvinylidene fluoride (PVDF), vinylidene fluoride VDF and PVDF-copolymer; and
• the second binder is selected from polytetrafluoroethylene (PTFE), PTFE-copolymer.
In an embodiment of the present disclosure,
• the predetermined amount of the active material is in the range of 94 mass% to 98 mass% with respect to the total mass of the positive electrode;
• the predetermined amount of the first conductive agent is in the range of 0.5 mass% to 2 mass% with respect to the total mass of the positive electrode;
• the predetermined amount of the second conductive agent is in the range of 0.1 mass% to 0.5 mass% with respect to the total mass of the positive electrode;
• the predetermined amount of the third conductive agent is in the range of 0.25 mass% to 0.5 mass% with respect to the total mass of the positive electrode;
• the predetermined amount of the first binder is in the range of 0.5 mass% to 1.5 mass% with respect to the total mass of the positive electrode; and
• the predetermined amount of the second binder is in the range of 0.5 mass% to 1.5 mass% with respect to the total mass of the positive electrode.
In an embodiment of the present disclosure, the positive electrode is characterized by having at least one of the following:
• average peel strength in the range of 0.75 N/25mm to 2 N/25mm;
• density in the range of 3.45 g/cc to 3.85 g/cc;
• conductivity in the range of 1 S/m to 2.5S/m;
• mass loading in the range of 22 mg/cm2 to 25 mg/cm2;
• thickness in the range of 70 µm to 78 µm; and
• through plane resistance in the range of 0.15 ohm to 0.3 ohm.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
The present disclosure will now be described with the help of the accompanying drawing, in which:
Figure 1a illustrates an SEM (Scanning Electron Microscope) image of a positive electrode prepared in Experiment 1 in accordance with the present disclosure;
Figure 1b illustrates a SEM (Scanning Electron Microscope) image of a positive electrode prepared in Comparative Experiment 1 in accordance with the present disclosure;
Figure 2 illustrates a comparative study for the density parameter for the positive electrodes obtained by the process of Experiment 1 and Comparative Experiments 1 to 2 in accordance with the present disclosure;
Figure 3 illustrates a comparative study for the peel strength parameter for the positive electrodes obtained by the process of Experiment 1 and Comparative Experiments 1 to 2 in accordance with the present disclosure; and
Figure 4 illustrates a comparative study of through plane resistance for the positive electrodes obtained by the process of Experiment 1 and Comparative Experiments 1 to 2 in accordance with the present disclosure.
DETAILED DESCRIPTION
The present disclosure relates to the field of batteries. Particularly, the present disclosure relates to a process for the preparation of a positive electrode.
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," “including,” and “having,” are open ended transitional phrases and therefore specify the presence of stated features, integers, steps, operations, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.
As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed elements.
The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element, component, region, layer or section from another component, region, layer or section. Terms such as first, second, third etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.
Dry electrode manufacturing is an emerging lithium-ion battery fabrication method that processes electrode components without solvents, relying on dry mixing and mechanical pressing. Unlike slurry-based methods where solvents aid in uniform dispersion, dry mixing often results in uneven distribution of active materials, binders, and conductive additives. Conventional conductive carbons like carbon black and graphite tend to agglomerate, forming non-uniform and discontinuous conductive networks that reduce electrical connectivity and mechanical strength. This leads to issues such as particle detachment, cracking, delamination and the like during manufacturing and cycling, causing low peel strength and poor electrode integrity. Further, uneven conductive pathways and weak structural support hinder efficient electrode packing. These drawbacks diminish battery performance by lowering rate capability, shortening cycle life and increasing safety risks.
In an aspect of the present disclosure, there is provided a process for the preparation of a positive electrode having optimum density, mechanical integrity and electrical conductivity across the electrode structure.
The process comprises the following steps:
i. mixing a predetermined amount of an active material, a predetermined amount of a first portion of a first conductive agent and a predetermined amount of a second conductive agent under stirring at a first predetermined speed and at a first predetermined temperature for a first predetermined time period to obtain a first mixture;
ii. adding a predetermined amount of a first binder to the first mixture under stirring at a second predetermined speed and at a second predetermined temperature for a second predetermined time period to obtain a second mixture;
iii. adding a predetermined amount of a second portion of the first conductive agent to the second mixture under stirring at a third predetermined speed and at a third predetermined temperature for a third predetermined time period to obtain a third mixture;
iv. adding a predetermined amount of a second binder to the third mixture under stirring at a fourth predetermined speed and at a fourth predetermined temperature for a fourth predetermined time period to obtain a fourth mixture;
v. adding a predetermined amount of a third conductive agent to the fourth mixture under stirring at a fifth predetermined speed and at a fifth predetermined temperature for a fifth predetermined time period to obtain a fifth mixture;
vi. mixing the fifth mixture under stirring at a sixth predetermined speed and at a sixth predetermined temperature for a sixth predetermined time period to obtain a resultant mixture; and
vii. cooling the resultant mixture to a seventh predetermined temperature by reducing the sixth predetermined speed to a seventh predetermined speed to obtain the positive electrode.
The process is described in detail.
Initially, a predetermined amount of an active material, a predetermined amount of a first portion of a first conductive agent and a predetermined amount of a second conductive agent are mixed under stirring at a first predetermined speed and at a first predetermined temperature for a first predetermined time period to obtain a first mixture.
In an embodiment of the present disclosure, the active material is a layered transition metal oxide, wherein the layered transition metal oxide is selected from the group consisting of lithium nickel manganese cobalt oxide (NMC 80+, NMC 811), lithium-rich transition metal oxide and spinel oxide. In an exemplary embodiment of the present disclosure, the active material is lithium nickel manganese cobalt oxide (NMC 80+).
In an embodiment of the present disclosure, the predetermined amount of the active material is in the range of 94 mass% to 98 mass% with respect to the total mass of the positive electrode. In an exemplary embodiment of the present disclosure, the predetermined amount of the active material is 96 mass% with respect to the total mass of the positive electrode.
In an embodiment of the present disclosure, the first conductive agent is selected from the group consisting of carbon black (Ketjen Black and Super-P), high surface area carbon, carbon nanofibers. In an exemplary embodiment of the present disclosure, the first conductive agent is Ketjen Black.
In an embodiment of the present disclosure, the predetermined amount of the first conductive agent is in the range of 0.5 mass% to 2 mass% with respect to the total mass of the positive electrode. In an exemplary embodiment of the present disclosure, the predetermined amount of the first conductive agent is 1.45 mass% with respect to the total mass of the positive electrode.
In an embodiment of the present disclosure, the first conductive agent is added in two portions.
In an embodiment of the present disclosure, the predetermined amount of the first portion of the first conductive agent is in the range of 60 mass% to 70 mass% with respect to the total mass of the first conductive agent. In an exemplary embodiment of the present disclosure, the predetermined amount of the first portion of the first conductive agent is 68.9 mass% with respect to the total mass of the first conductive agent.
The first conductive agent has a high surface area and its addition in two portions improves the coating of the active material by enhancing the dispersion and interaction with the first conductive agent.
In an embodiment of the present disclosure, the second conductive agent is selected from the group consisting of natural graphite, synthetic graphite and carbon nanotube (CNT). In an exemplary embodiment of the present disclosure, the second conductive agent is a synthetic graphite (KS6L).
In an embodiment of the present disclosure, the predetermined amount of the second conductive agent is in the range of 0.1 mass% to 0.5 mass% with respect to the total mass of the positive electrode. In an exemplary embodiment of the present disclosure, the predetermined amount of the second conductive agent is 0.3 mass% with respect to the total mass of the positive electrode.
In an embodiment of the present disclosure, the first predetermined speed is in the range of 2500 rpm to 3500 rpm. In an exemplary embodiment of the present disclosure, the first predetermined speed is 3000 rpm.
In an embodiment of the present disclosure, the first predetermined temperature is in the range of 15 °C to 30° C. In an exemplary embodiment of the present disclosure, the first predetermined temperature is in the range of 22 °C to 25 °C.
In an embodiment of the present disclosure, the first predetermined time period is in the range of 60 minutes to 120 minutes. In an exemplary embodiment of the present disclosure, the first predetermined time period is 75 minutes.
In the next step, a predetermined amount of a first binder is added to the first mixture under stirring at a second predetermined speed and at a second predetermined temperature for a second predetermined time period to obtain a second mixture.
In an embodiment of the present disclosure, the first binder is selected from the group consisting of polyvinylidene fluoride (PVDF), vinylidene fluoride (VDF) and polyvinylidene fluoride (PVDF)-copolymer. In an exemplary embodiment of the present disclosure, the first binder is polyvinylidene fluoride (PVDF).
In an embodiment of the present disclosure, the predetermined amount of the first binder is in the range of 0.5 mass% to 1.5 mass% with respect to the total mass of the positive electrode. In an exemplary embodiment of the present disclosure, the predetermined amount of the first binder is 0.9 % with respect to the total mass of the positive electrode.
In an embodiment of the present disclosure, the second predetermined speed is in the range of 1000 rpm to 2000 rpm. In an exemplary embodiment of the present disclosure, the second predetermined speed is 1500 rpm.
In an embodiment of the present disclosure, the second predetermined temperature is in the range of 10 °C to 19 °C. In an exemplary embodiment of the present disclosure, the second predetermined temperature is in the range of 15 °C to 19 °C.
After the addition of the first binder, the temperature is maintained in the range of 10 °C to 19 °C, so that the binder effectively interacts with the other components without premature curing or degradation, thereby ensuring optimal consistency and processability. Once all components have been added, the temperature is increased to a range of 60 °C to 90 °C to facilitate the final mixing and achieve a uniform and stable positive electrode. In an embodiment of the present disclosure, the second predetermined time period is in the range of 5 minutes to 25 minutes. In an exemplary embodiment of the present disclosure, the second predetermined time period is 15 minutes.
In the next step, a predetermined amount of a second portion of the first conductive agent is added to the second mixture under stirring at a third predetermined speed and at a third predetermined temperature for a third predetermined time period to obtain a third mixture.
In an embodiment of the present disclosure, the second portion of the first conductive agent is in the range of 30 mass% to 40 mass% with respect to the total mass of the first conductive agent. In an exemplary embodiment of the present disclosure, the second portion of the first conductive agent is 31.1 mass% with respect to the total mass of the first conductive agent.
In an embodiment of the present disclosure, the third predetermined speed is in the range of 1000 rpm to 2000 rpm. In an exemplary embodiment of the present disclosure, the third predetermined speed is 1500 rpm.
In an embodiment of the present disclosure, the third predetermined temperature is in the range of 10 °C to 19 °C. In an exemplary embodiment of the present disclosure, the third predetermined temperature is in the range of 15 °C to 19 °C.
In an embodiment of the present disclosure, the third predetermined time period is in the range of 20 minutes to 40 minutes. In an exemplary embodiment of the present disclosure, the third predetermined time period is 30 minutes.
In the next step, a predetermined amount of a second binder is added to the third mixture under stirring at a fourth predetermined speed and at a fourth predetermined temperature for a fourth predetermined time period to obtain a fourth mixture.
In an embodiment of the present disclosure, the second binder is selected from the group consisting of polytetrafluoroethylene (PTFE), polytetrafluoroethylene (PTFE)-copolymer. In an exemplary embodiment of the present disclosure, the second binder is polytetrafluoroethylene (PTFE).
In an embodiment of the present disclosure, the fourth predetermined speed is in the range of 1000 rpm to 2000 rpm. In an exemplary embodiment of the present disclosure, the fourth predetermined speed is 1500 rpm.
In an embodiment of the present disclosure, the fourth predetermined temperature is in the range of 10 °C to 20 °C. In an exemplary embodiment of the present disclosure, the fourth predetermined temperature is in the range of 15 °C to 19 °C.
In an embodiment of the present disclosure, the fourth predetermined time period is in the range of 5 minutes to 25 minutes. In an exemplary embodiment of the present disclosure, the fourth predetermined time period is 15 minutes.
In the next step, a predetermined amount of a third conductive agent is added to the fourth mixture under stirring at a fifth predetermined speed and at a fifth predetermined temperature for a fifth predetermined time period to obtain a fifth mixture.
In an embodiment of the present disclosure, the third conductive agent is selected from graphene (Procharge+Dry2) and reduced graphene. In an exemplary embodiment of the present disclosure, the third conductive agent is Procharge+Dry2.
Graphene is a two-dimensional, pure carbon material with high electrical and mechanical properties, while reduced graphene (reduced graphene oxide, or rGO) is a derivative of graphene oxide (GO) where most oxygen-containing functional groups are removed, restoring some of graphene's conductivity and mechanical strength but with a less perfect structure and lower overall performance than pristine graphene.
In an embodiment of the present disclosure, the predetermined amount of the third conductive agent is in the range of 0.25 mass% to 0.5 mass% with respect to the total mass of the positive electrode. In an exemplary embodiment of the present disclosure, the predetermined amount of the third conductive agent is 0.45 mass% with respect to the total mass of the positive electrode.
In an embodiment of the present disclosure, the third conductive agent is graphene. Graphene provides high-aspect-ratio conductive networks and enhances flexibility in the 3-D conductive channel. Graphene’s flexibility and ability to deform under pressure, does not place excessive stress on the pressing equipment during pressing. This allows to achieve high electrode density without damaging the rollers, making graphene a cost-effective choice in the long term. A high amount of graphene can reduce peel strength, hence the amount of graphene is limited to 0.45% of the total positive electrode to provide optimum performance and mechanical integrity.
The sequence of adding graphene in the dry electrode mixing process is critical to ensure optimal dispersion, electrical performance, and mechanical integrity. By introducing graphene at a later stage, i.e., after the primary conductive agents and binders are well distributed, its tendency to agglomerate is minimized, preserving its high conductivity and structural benefits. This timing also prevents over-shearing and allows graphene to effectively enhance the conductive network without compromising binder adhesion or peel strength resulting in a dense, well-connected electrode structure with improved performance and process stability.
In an embodiment of the present disclosure, the fifth predetermined speed is in the range of 1000 rpm to 2000 rpm. In an exemplary embodiment of the present disclosure, the fifth predetermined speed is 1500 rpm.
In an embodiment of the present disclosure, the fifth predetermined temperature is in the range of 10 °C to 19 °C. In an exemplary embodiment of the present disclosure, the fifth predetermined temperature is in the range of 15 °C to 19 °C.
In an embodiment of the present disclosure, the fifth predetermined time period is in the range of 20 minutes to 40 minutes. In an exemplary embodiment of the present disclosure, the fifth predetermined time period is 30 minutes.
In the next step, the fifth mixture is mixed under stirring at a sixth predetermined speed and at a sixth predetermined temperature for a sixth predetermined time period to obtain a resultant mixture.
In an embodiment of the present disclosure, the sixth predetermined speed is in the range of 2500 rpm to 3500 rpm. In an exemplary embodiment of the present disclosure, the sixth predetermined speed is 3000 rpm.
In an embodiment of the present disclosure, fifth mixture is mixed in a shear mixer to homogenously blend the components. The high shear forces generated by the mixer facilitate the uniform dispersion and thorough blending of all the components. This process ensures a homogenous mixture with consistent texture and composition, which is critical for the performance and quality of the positive electrode.
In an embodiment of the present disclosure, the sixth predetermined temperature is in the range of 60 °C to 90 °C. In an exemplary embodiment of the present disclosure, the sixth predetermined temperature is 70 °C.
The high shear force together with the high stirring speed results in the increase of temperature in the range of 60 °C to 90 °C. The temperature is decreased in the subsequent step by reducing the stirring speed. In an embodiment of the present disclosure, the sixth predetermined time period is in the range of 15 minutes to 25minutes. In an exemplary embodiment of the present disclosure, the sixth predetermined time period is 16 minutes.
The so-obtained resultant mixture is cooled to a seventh predetermined temperature by reducing the sixth predetermined speed to a seventh predetermined speed to obtain the positive electrode.
In an embodiment of the present disclosure, the seventh predetermined speed is in the range of 400 rpm to 700 rpm. In an exemplary embodiment of the present disclosure, the seventh predetermined speed is 600 rpm.
In an embodiment of the present disclosure, the seventh predetermined temperature is in the range of 10 °C to 19 °C. In an exemplary embodiment of the present disclosure, the seventh predetermined temperature is 18.9 °C.
In an embodiment of the present disclosure, the positive electrode is calendared to achieve a density in the range of 3.45 g/cc to 3.85 g/cc.
In an embodiment of the present disclosure, the positive electrode is passed through high-pressure rollers to compress it to a specific thickness and density.
Graphene exhibits a “sponge-like” mechanical behavior, wherein its layered flexibility allows it to deform and conform around active material particles during calendaring, which minimizes particle rebound and spring-back effects, leading to improved particle interlocking and mechanical stability of the electrode. As a result, graphene not only enhances packing density but also contributes to better mechanical integrity and electrical conductivity across the electrode structure.
In another aspect of the present disclosure, there is provided a positive electrode comprising
• a predetermined amount of an active material;
• a predetermined amount of a first conductive agent;
• a predetermined amount of a second conductive agent;
• a predetermined amount of a third conductive agent;
• a predetermined amount of a first binder; and
• a predetermined amount of a second binder.
In an embodiment of the present disclosure,
• the active material is a layered transition metal oxide, wherein the layered transition metal oxide is selected from the group consisting of lithium nickel manganese cobalt oxide, lithium-rich transition metal oxide and spinel oxide;
• the first conductive agent is selected from the group consisting of carbon black, high surface area carbon and carbon nanofibers;
• the second conductive agent is selected from the group consisting of natural graphite, synthetic graphite and carbon nanotube (CNT);
• the third conductive layer is selected from graphene and reduced graphene.
• the first binder is selected from the group consisting of polyvinylidene fluoride (PVDF), vinylidene fluoride (VDF) and polyvinylidene fluoride (PVDF)-copolymer; and
• the second binder is selected from polytetrafluoroethylene (PTFE) and polytetrafluoroethylene (PTFE)-copolymer.
In embodiment of the present disclosure,
• the predetermined amount of the active material is in the range of 94 mass% to 98 mass% with respect to the total mass of the positive electrode;
• the predetermined amount of the first conductive agent is in the range of 0.5 mass% to 2 mass% with respect to the total mass of the positive electrode;
• the predetermined amount of the second conductive agent is in the range of 0.1 mass% to 0.5 mass% with respect to the total mass of the positive electrode;
• the predetermined amount of the third conductive layer is in the range of 0.25 mass% to 0.5 mass% with respect to the total mass of the positive electrode;
• the predetermined amount of the first binder is in the range of 0.5 mass% to 1.5 mass% with respect to the total mass of the positive electrode; and
• the predetermined amount of the second binder is in the range of 0.5 mass% to 1.5 mass% with respect to the total mass of the positive electrode.
In an embodiment of the present disclosure, the positive electrode is characterized by having at least one of the following:
• average peel strength in the range of 0.75 N/25mm to 2 N/25mm;
• density in the range of 3.45 g/cc to 3.85 g/cc;
• conductivity in the range of 1 S/m to 2.5 S/m;
• mass loading in the range of 22 mg/cm2 to 25 mg/cm2;
• thickness in the range of 70 µm to 78 µm; and
• through plane resistance in the range of 0.15 ohm to 0.3 ohm.
In an exemplary embodiment of the present disclosure, the positive electrode is characterized by having at least one of the following:
• average peel strength in the range of 1 N/25mm;
• density of 3.8 g/cc;
• conductivity of 1.21 S/m;
• mass loading of 22.9 mg/cm2;
• thickness in the range of 72 µm; and
• through plane resistance of 0.2 ohm.
The process of the present disclosure uses a three-conductive-carbon system during the powder mixing stage, which improves the peel strength for superior adhesion and mechanical integrity, increases electrical conductivity to facilitate efficient electron transport, and boosts electrode density to maximize energy storage capacity per unit volume.
The different conducting agents used on the present disclosure aids in the particle-level conductivity, dispersion and conductivity. Particularly, graphene (third conducting agent) provides high-aspect-ratio conductive networks. Graphene enhances flexibility in the 3-D conductive channel. Graphene’s flexibility and ability to deform under pressure, does not place excessive stress on the pressing equipment during pressing. This allows to achieve high electrode density without damaging the rollers, making graphene a cost-effective choice in the long term.
The positive electrode obtained by the process of the present disclosure provides has enhanced mechanical strength, electrical conductivity, and density of dry-processed electrodes.
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment but are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
The present disclosure is further illustrated herein below with the help of the following non-limiting examples. The experiments disclosed under these examples herein are intended merely to facilitate an understanding of how the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the experiments should not be construed as limiting the scope of embodiments herein. These laboratory-scale experiments can be scaled up to an industrial/ commercial scale and the results obtained can be extrapolated to industrial/ commercial scale.
EXPERIMENTAL DETAILS
Experiment 1: Process for the preparation of the positive electrode in accordance with the present disclosure
4800 g of NMC-Bimodal (NMC 80+) (active material), 50 g of Ketjen Black (first portion of first conductive agent) and 15 g of graphite (second conductive agent) were mixed under stirring at a speed of 3000 rpm (first predetermined speed) at 22 °C to 25 °C (first predetermined temperature) for 75 minutes (first predetermined time period) to obtain a first mixture. 45 g polyvinylidene fluoride (first binder) was then added to the first mixture under stirring at a speed of 1500 rpm (second predetermined speed) at 15 °C to 19 °C (second predetermined temperature) for 15 minutes (second predetermined time period) to obtain a second mixture. 22.5 g of Ketjen Black (second portion of first conductive agent) was added to the second mixture under stirring at a speed of 1500 rpm (third predetermined speed) at 15 °C to 19 °C (third predetermined temperature) for 30 minutes (third predetermined time period) to obtain a third mixture. 45 g of polytetrafluoroethylene (second binder) was added to the third mixture under stirring at a speed of 1500 rpm (fourth predetermined speed) at 15 °C to 19 °C (fourth predetermined temperature) for 15 minutes (fourth predetermined time period) to obtain a fourth mixture. 22.5 g of procharge+dry2 (third conductive agent) was added to the fourth mixture under stirring at a speed of 1500 rpm (fifth predetermined speed) and (fifth predetermined temperature) for 30 minutes (fifth predetermined time period) to obtain a fifth mixture. The fifth mixture was mixed under stirring at a speed of 3000 rpm (sixth predetermined speed) at 70 °C (sixth predetermined temperature) for 16 minutes (sixth predetermined time period) to obtain a resultant mixture, which was then cooled to 18.9 °C (seventh predetermined temperature) by reducing the speed from 3000 rpm (sixth predetermined speed) to 600 rpm (seventh predetermined speed) to obtain the positive electrode.
The ingredients used along with their amount are summarized in Table 1.
Comparative Experiment 1:
Comparative experiment 1 (C1) was carried out similar to Experiment 1, except that graphene was not used. Ketjen Black was used in place of graphene as the third conductive agent.
The ingredients used along with their amounts are summarized in Table 1.
Comparative Experiment 2:
Comparative Experiment 2 (C2) was carried out similar to Experiment 1, except that graphene (third conductive agent) was added in the first step and Ketjen Black was added in the fifth step (first conductive agent).
The ingredients used along with their amount are summarized in Table 1.

Table 1: Composition of positive electrode in accordance with the present disclosure and comparative experiments
Expt. No. Active material First conductive agent Second conductive agent Third conductive agent First binder Second binder Composition
Expt-1 NMC- BiModal
Ketjen Black KS6L Graphene
PVDF PTFE AM:FCA1:SCA: (FB+FCA2):(SB:TCA)
96:1.0:0.3: (0.9+(0.45)):(0.9+(0.45)
(4800:50:15:(45+(22.5):(45+(22.5)
C1 NMC- BiModal Ketjen Black KS6L Ketjen Black PVDF PTFE AM:FCA1:SCA: (FB+FCA2):(SB:TCA)
96:1.0:0.3:(0.9+(0.45)):(0.9+(0.45)
(4800:50:15:(45+(22.5):(45+(22.5)
C2 NMC- BiModal
Ketjen Black Graphene
Ketjen Black PVDF PTFE AM:FCA1:SCA: (FB+FCA2):(SB:TCA)
96:1.0:0.3:(0.9+(0.45)): (0.9+(0.45)
(4800:50:15:(45+(22.5):(45+(22.5)
NMC-BiModal=Lithium nickel manganese cobalt oxide; KS6L= Graphitic Conducting Carbon; AM=active material; FCA1=first portion of first conductive agent; SCA: second conductive agent; FB=first binder; FCA2=second portion of first conductive agent; SB=second binder; TCA=third conductive agent

Experiment 2: Characterization of the positive electrodes prepared in accordance with the present disclosure
The positive electrodes prepared in Experiment 1 and Comparative Experiments 1 to 2 were analyzed and the results obtained are summarized in Tables 2 to 7.
Surface morphology using Scanning Electron Microscope (SEM)
Figure 1a illustrates an SEM image of a positive electrode prepared in Experiment 1 (E1) and Figure 1b illustrates an SEM image of a positive electrode prepared in Comparative Experiment 1 (C1).
It is seen from Figure 1a and Figure 1b that the positive electrode (E1) of the present disclosure comprising graphene exhibited significantly reduced agglomeration of binder and the conductive agent.
In C1, the conductive agent particles tend to cluster with the binder, forming localized agglomerates. Whereas, the graphene used in the present disclosure, has a two-dimensional structure and high surface area, which during the high shear mixing disperses more uniformly with the active material, leading to a more homogeneous electrode microstructure.
Peel strength
The average peel strength was analyzed by Peel tester (UTM Machine) by the following method: The peel strength of the various electrodes was measured using scotch tape method where a scotch tape was pasted over the dry battery electrode in the dimension of (100 mm length and 25 mm width). The prepared electrode was fixed with fixtures at top and bottom. Then a load was applied. The results obtained are summarized in Table 2 and Figure 3.
Table 2: Average peel strength of the positive electrodes in accordance with the present disclosure and comparative experiments
Experiment No. Peel Strength
MD
(N/25 mm) Peel Strength
TD
(N/25 mm) Average Peel Strength (N/25 mm)
Experiment 1 0.91 1.09 1
Comparative Experiment 1 1.04 0.78 0.91
Comparative Experiment 2 0.95 0.94 0.95
It is seen from Table 2 and Figure 3 that the positive electrode of the present disclosure comprising graphene achieved higher average peel strength compared to the positive electrodes without graphene or when sequence of graphene addition was changed.

Through Plane Resistance
The resistance of the positive electrodes prepared in experiments E1 and C1-C2 was measured by Through plane resistance analyser/ impedance analyzer. The results obtained are summarized in Table 3 and Figure 4.
Table 3: Resistance of the positive electrode in accordance with the present disclosure and comparative experiments
Experiment No. Through plane resistance (Ohm)
Experiment 1 0.2
Comparative Experiment 1 0.17
Comparative Experiment 2 0.34
It is seen from Table 3 and Figure 4 that the positive electrode of the present disclosure comprising graphene achieved optimum resistance compared to the positive electrodes without graphene or when sequence of graphene addition was changed.
Mass loading
The mass loading of the positive electrodes prepared in experiments E1 and C1-C2 was measured by taking a sample of 15 mm diameter and weighed using the weighing balance The results obtained are summarized in Table 4.
Table 4: Mass loading of the positive electrode in accordance with the present disclosure and comparative experiments
Experiment No. Mass loading (mg/cm2)
Experiment 1 22.9
Comparative Experiment 1 24.12
Comparative Experiment 2 22.3
Mass loading refers to the active material coated on to the surface of an electrode. Higher mass loading can increase energy density but may cause poor conductivity, slower ion transport, and mechanical issues. Lower mass loading improves rate capability and cycle life but limits energy capacity. Therefore, optimizing mass loading is key to balancing energy density, power, and durability. It is seen from Table 4 that the positive electrode of the present disclosure has an optimal mass loading (22.9 mg/cm2) that significantly influences its properties.
Thickness
The thickness of the positive electrodes prepared in experiments E1 and C1-C2 was measured by the thickness gauge from Mahr using the instrument Millimar C1202. The results obtained are summarized in Table 5.
Table 5: Thickness of the positive electrode in accordance with the present disclosure and comparative experiments
Experiment No. Thickness (µm)
Experiment 1 72.0
Comparative Experiment 1 79.6
Comparative Experiment 2 79.1
It is seen from Table 5 that the positive electrode (72.0 µm) of the present disclosure is thinner than those in Comparative Experiment 1 (79.6 µm) and Comparative Experiment 2 (79.1 µm). The process of the present disclosure leads to better compaction or densification of the electrode material during fabrication, improving electrode density, mechanical integrity, and electrochemical performance.
Density
The density of the positive electrodes prepared in experiments E1 and C1-C2 was measured using the formula:
Density = Mass loading/Thickness of the free-standing film (without current collector).
Density was measured by Thickness gauge and Weighing balance. The results obtained are summarized in Table 6 and Figure 2.
Table 6: Density of the positive electrode in accordance with the present disclosure and comparative experiments
Experiment No. Density (g/cc)
Experiment 1 3.8
Comparative Experiment 1 3.57
Comparative Experiment 2 3.32
It is seen from Table 6 and Figure 2 that the positive electrode (E1) of the present disclosure comprising graphene achieved higher density compared to the positive electrodes without graphene (C1) or when sequence of graphene addition was changed (C2). The sponge-like structure of graphene provides a flexible, porous platform that facilitates the accommodation and compaction of more active material during the lamination process, resulting in comparatively higher density of the positive electrode.
Conductivity measurement
The conductivity of the positive electrodes prepared in experiments E1 and C1-C2 was measured by Through plane resistance analyser/ impedance analyzer. The results obtained are summarized in Table 7.
Table 7: Conductivity of the positive electrode in accordance with the present disclosure and comparative experiments
Experiment No. Conductivity (S/m)
Experiment 1 1.21
Comparative Experiment 1 1.46
Comparative Experiment 2 0.7
It is seen from Table 7 that the positive electrode of the present disclosure provides a balanced conductivity performance.
TECHNICAL ADVANCEMENTS
The present disclosure described hereinabove has several technical advantages including, but not limited to, the realization of a process for the preparation of a positive electrode that:
• is simple, economic and scalable;
and
a positive electrode that:
• has improved peel strength, and conductivity;
• has improved mechanical strength and density; and
• has better life cycle retention.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or are common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation. , Claims:WE CLAIM:
1. A process for the preparation of a positive electrode, said process comprising the following steps:
i. mixing a predetermined amount of an active material, a predetermined amount of a first portion of a first conductive agent and a predetermined amount of a second conductive agent under stirring at a first predetermined speed and at a first predetermined temperature for a first predetermined time period to obtain a first mixture;
ii. adding a predetermined amount of a first binder to said first mixture under stirring at a second predetermined speed and at a second predetermined temperature for a second predetermined time period to obtain a second mixture;
iii. adding a predetermined amount of a second portion of said first conductive agent to said second mixture under stirring at a third predetermined speed and at a third predetermined temperature for a third predetermined time period to obtain a third mixture;
iv. adding a predetermined amount of a second binder to said third mixture under stirring at a fourth predetermined speed and at a fourth predetermined temperature for a fourth predetermined time period to obtain a fourth mixture;
v. adding a predetermined amount of a third conductive agent to said fourth mixture under stirring at a fifth predetermined speed and at a fifth predetermined temperature for a fifth predetermined time period to obtain a fifth mixture;
vi. mixing said fifth mixture under stirring at a sixth predetermined speed and at a sixth predetermined temperature for a sixth predetermined time period to obtain a resultant mixture; and
vii. cooling said resultant mixture to a seventh predetermined temperature by reducing said sixth predetermined speed to a seventh predetermined speed to obtain said positive electrode.
2. The process as claimed in claim 1, wherein said active material is a layered transition metal oxide, wherein said layered transition metal oxide is selected from the group consisting of lithium nickel manganese cobalt oxide, lithium-rich transition metal oxide and spinel oxide.
3. The process as claimed in claim 1, wherein said first conductive agent is selected from the group consisting of carbon black, high surface area carbon and carbon nanofibers.
4. The process as claimed in claim 1, wherein said second conductive agent is selected from the group consisting of natural graphite, synthetic graphite, and carbon nanotube (CNT).
5. The process as claimed in claim 1, wherein said third conductive agent is selected from graphene and reduced graphene.
6. The process as claimed in claim 1, wherein said first binder is selected from the group consisting of polyvinylidene fluoride (PVDF), vinylidene fluoride (VDF) and polyvinylidene fluoride (PVDF)-copolymer.
7. The process as claimed in claim 1, wherein said second binder is selected from polytetrafluoroethylene (PTFE) and polytetrafluoroethylene (PTFE)-copolymer.
8. The process as claimed in claim 1, wherein
• said predetermined amount of said active material is in the range of 94 mass% to 98 mass% with respect to the total mass of said positive electrode;
• said predetermined amount of said first conductive agent is in the range of 0.5 mass% to 2 mass% with respect to the total mass of said positive electrode;
• said predetermined amount of said second conductive agent is in the range of 0.1 mass% to 0.5 mass% with respect to the total mass of said positive electrode;
• said predetermined amount of said third conductive agent is in the range of 0.25 mass% to 0.5 mass% with respect to the total mass of said positive electrode;
• said predetermined amount of said first binder is in the range of 0.5 mass% to 1.5 mass% with respect to the total mass of said positive electrode; and
• said predetermined amount of said second binder is in the range of 0.5 mass% to 1.5 mass% with respect to the total mass of said positive electrode.
9. The process as claimed in claim 1, wherein
• said predetermined amount of said first portion of said first conductive agent is in the range of 60 mass% to 70 mass% with respect to the total mass of said first conductive agent; and
• said predetermined amount of said second portion of said first conductive agent is in the range of 30 mass% to 40 mass% with respect to the total mass of said first conductive agent.
10. The process as claimed in claim 1, wherein
• said first predetermined speed is in the range of 2500 rpm to 3500 rpm;
• said second predetermined speed, said third predetermined speed, said fourth predetermined speed and said fifth predetermined speed are independently in the range of 1000 rpm to 2000 rpm;
• said sixth predetermined speed is in the range of 2500 rpm to 3500 rpm; and
• said seventh predetermined speed is in the range of 400 rpm to 700 rpm.
11. The process as claimed in claim 1, wherein
• said first predetermined temperature is in the range of 15 °C to 30°C;
• said second predetermined temperature, said third predetermined temperature, said fourth predetermined temperature, said fifth predetermined temperature and said seventh predetermined temperature are independently in the range of 10 °C to 19 °C; and
• said sixth predetermined temperature is in the range of 60 °C to 90 °C
12. The process as claimed in claim 1, wherein
• said first predetermined time period is in the range of 60 minutes to 120 minutes;
• said second predetermined time period and said fourth predetermined time period are independently in the range of 5 minutes to 25 minutes;
• said third predetermined time period and said fifth predetermined time period are independently in the range of 20 minutes to 40 minutes; and
• said sixth predetermined time period is in the range of 15 minutes to 25 minutes.
13. The process as claimed in claim 1, wherein said positive electrode is calendared to achieve a density in the range of 3.45 g/cc to 3.85 g/cc.
14. A positive electrode obtained by the process as claimed in claim 1 comprising;
• a predetermined amount of an active material;
• a predetermined amount of a first conductive agent;
• a predetermined amount of a second conductive agent;
• a predetermined amount of a third conductive agent;
• a predetermined amount of a first binder; and
• a predetermined amount of a second binder.
15. The positive electrode as claimed in claim 14, wherein
• said active material is a layered transition metal oxide, wherein said layered transition metal oxide is selected from the group consisting of lithium nickel manganese cobalt oxide, lithium-rich transition metal oxide and spinel oxide;
• said first conductive agent is selected from the group consisting of carbon black, high surface area carbon and carbon nanofibers;
• said second conductive agent is selected from the group consisting of natural graphite, synthetic graphite, and carbon nanotube (CNT);
• said third conductive layer is selected from graphene and reduced graphene.
• said first binder is selected from the group consisting of polyvinylidene fluoride (PVDF), vinylidene fluoride (VDF) and polyvinylidene fluoride (PVDF)-copolymer; and
• said second binder is selected from polytetrafluoroethylene (PTFE) and polytetrafluoroethylene (PTFE)-copolymer.
16. The positive electrode as claimed in claim 14, wherein
• said predetermined amount of said active material is in the range of 94 mass% to 98 mass% with respect to the total mass of said positive electrode;
• said predetermined amount of said first conductive agent is in the range of 0.5 mass% to 2 mass% with respect to the total mass of said positive electrode;
• said predetermined amount of said second conductive agent is in the range of 0.1 mass% to 0.5 mass% with respect to the total mass of said positive electrode;
• said predetermined amount of said third conductive agent is in the range of 0.25 mass% to 0.5 mass% with respect to the total mass of said positive electrode;
• said predetermined amount of said first binder is in the range of 0.5 mass% to 1.5 mass% with respect to the total mass of said positive electrode; and
• said predetermined amount of said second binder is in the range of 0.5 mass% to 1.5 mass% with respect to the total mass of said positive electrode.
17. The positive electrode as claimed in claim 14 is characterized by having at least one of the following:
• average peel strength in the range of 0.75 N/25mm to 2 N/25mm;
• density in the range of 3.45 g/cc to 3.85 g/cc;
• conductivity in the range of 1 S/m to 2.5 S/m;
• mass loading in the range of 22 mg/cm2 to 25 mg/cm2;
• thickness in the range of 70 µm to 78 µm; and
• through plane resistance 0.15 ohm to 0.3 ohm.

Dated this 29th Day of September 2025

_______________________________
MOHAN RAJKUMAR DEWAN, IN/PA – 25
OF R. K. DEWAN & CO.
AUTHORIZED AGENT OF APPLICANT

TO,
THE CONTROLLER OF PATENTS
THE PATENT OFFICE, AT MUMBAI