Description:FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)
1. Title: ‘ELECTRODE MATERIAL FOR SUPERCAPACITORS AND METHOD THEREOF’
2.
APPLICANT DETAILS:
(a) NAME: WESTECHPOWER MANAGEMENT PRIVATE LIMITED
(b) NATIONALITY: IN
(c) ADDRESS: M/s WESTECHPOWER MANAGEMENT PRIVATE LIMITED,
TRIVENI NAGAR, TALAWADE, PUNE, MAHARASHTRA –
411062
PREAMBLE TO THE DESCRIPTION:
The following specification particularly describes the nature of the invention and the manner in which it is to be performed:
2
ELECTRODE MATERIAL FOR SUPERCAPACITORS AND METHOD THEREOF
FIELD OF THE INVENTION:
The invention relates to an electrode material for supercapacitors, offering enhanced energy storage capabilities and improved performance.
BACKGROUND OF THE INVENTION:
The following background discussion includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
Supercapacitors, also known as electrochemical capacitors, play a crucial role in various electronic devices and renewable energy systems. The efficiency of supercapacitors depends significantly on the characteristics of their electrode materials. For example, CN109155204B discloses a supercapacitor includes a first electrode, a second electrode, a separator, a nonaqueous electrolyte, and a case. The first electrode includes a first current collector electrically connected to the first carbonaceous coating and the second electrode includes a second current collector electrically connected to the second carbonaceous coating. The first current collector and the second current collector each comprise a substrate comprising an electrically conductive metal, wherein the plurality of fibrous whiskers protrudes outward from the substrate of the first current collector, the substrate of the second current collector, or both.
Further, WO2018167789A2 discloses a method for the preparation of printable electrodes, suitable for use in supercapacitors, and in particular for the application of an electrode composition to heat-sensitive substrates. The method of the invention incudes providing a substantially flat substrate; providing a flowable electrode composition comprising an aqueous electrolyte and a dry matter, wherein the dry matter content (DMC) of the flowable electrode composition ranges from about 25% to about 65% (w/w); placing a thin screen or a stencil having at least one opening over a top surface of the flat substrate; contacting a top surface of the screen or stencil with the flowable composition; removing the thin screen or stencil from the top surface of the substrate; and blotting the substrate and the electrode composition applied thereon under pressure of between about 5 to about 150 bar, thereby obtaining a printed electrode having a DMC of between about 30% (w/w) to about 75% (w/w). The invention
3
further provides printed electrodes, which can be prepared in a highly reproducible manner by the method of the invention.
In another document, RU2676530C2 discloses electrodes of supercapacitors, containing particles of an activated material, carrying a charge, graphene carbon particles and a binder. Particles of the activated material carrying the charge may contain activated carbon, while the graphene carbon particles are thermally produced at temperatures above 3500 °C. Electrodes may also contain electrically conductive carbon. In the manufacture of supercapacitor electrodes in a coating deposited on a foil substrate, enter these graphene carbon particles in an amount of from 1 to 10 wt. %, which provide an increase in the specific capacity of the electrode and an increase in its conductivity. Conductive carbon together with graphene carbon particles obtained by the thermal method at temperatures above 3500 °C, demonstrates higher capacitance with the stability of the electrode for cyclic operation. The conductive carbon together with graphene carbon particles demonstrates a higher capacity with the stability of the electrode for cyclic operation.
Further, KR20220070027A discloses an asymmetric supercapacitor having an anode, a cathode, and a biasing electrode disposed between the anode and cathode. As the supercapacitor charges, the biasing electrode accumulates an amount of charge equivalent to its mass balance, and an independent voltage applied to the biasing electrode forces the charge to the anode or cathode, maintaining equilibrium in the charge double layer. In one embodiment, the operating voltage is between about 5.5 and 7.4V in a coin cell form factor. The anode and biasing electrode are made of the same material, in one embodiment made of activated carbon and graphene nanoplates. The negative electrode may also include different amounts of activated carbon and graphene nanoplates from the positive electrode so that the weight ratio of the positive electrode to the negative electrode is not 1:1. The negative electrode may also include lithiated graphite.
However, all these cited documents have one or more shortcomings. The present invention addresses the shortcomings by increasing energy density, extended cycle life, and improved stability of the electrode of the supercapacitors.
OBJECTIVE OF THE INVENTION:
The primary object of the present invention is to overcome the drawback associated with prior art.
4
Another object of the present invention is to provide an electrode material for supercapacitors.
Another object of the present invention is to provide an electrode material for supercapacitors that offers enhanced energy storage capabilities.
Another object of the present invention is to provide an electrode material for supercapacitors that offers improved performance.
SUMMARY OF THE INVENTION:
In an aspect, the present invention provides an electrode composition for supercapacitors comprising:
a)
a coconut shell-derived steam-activated carbon powder;
b)
a graphene in powder form;
c)
a conducting carbon in powder form;
d)
a carboxymethyl cellulose; and
e)
at least two liquid solvent presents in equal percentage.
In an embodiment, the coconut shell-derived steam-activated carbon powder present in range of 65%.
In an embodiment, the graphene in powder and fluffy form present in range of 10%.
In an embodiment, the conducting carbon in powder and fluffy form present in range of 20%.
In an embodiment, the carboxymethyl cellulose present in range of 5% in powder form act as a binder.
In an embodiment, the two liquid two liquid solvent comprises an isopropyl alcohol and a DI water.
In an embodiment, the isopropyl alcohol present in range of 50%.
In an embodiment, the DI water present in range of 50%.
In an aspect, the present invention provides a method of preparing electrode composition for supercapacitors comprising steps of:
5
a) mixing coconut shell-derived steam-activated carbon powder, graphene powder, conducting carbon powder and carboxymethyl cellulose powder in a ribbon mixer machine for 30 minutes;
b) transferring the mixture obtained in step (a) in a vacuum planetary mixer and adding two liquid solvents in equal percentage; and
c) mixing the mixture obtained in step (b) in the vacuum planetary mixer to obtain a slurry viscosity ranging from 3000 to 10000 centipoise (CPS).
In an embodiment, the slurry serves as the electrode material for the fabrication of supercapacitors.
DETAILED DESCRIPTION OF DRAWINGS: To further clarify advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of their scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings in which:
Fig. 1: Illustrate the slurry making process of the present invention.
Fig. 2: Illustrate the electrode formation of the present invention.
Fig. 3 Illustrate the cyclic voltammogram of a 2032-coin cell at various voltage scan rates of the present invention.
Fig. 4: Illustrate the charge discharge curve of a 2032-coin cell at various current densities of the present invention.
DETAILED DESCRIPTION:
For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
6
It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be restrictive thereof.
In an embodiment, the present invention provides an electrode material for supercapacitors.
Another object of the present invention is to provide an electrode material for supercapacitors that offers enhanced energy storage capabilities.
Another object of the present invention is to provide an electrode material for supercapacitors that offers improved performance.
In an aspect, the present invention provides an electrode composition for supercapacitors comprising:
a)
a coconut shell-derived steam-activated carbon powder;
b)
a graphene in powder form;
c)
a conducting carbon in powder form;
d)
a carboxymethyl cellulose; and
e)
at least two liquid solvent presents in equal percentage.
In an embodiment, the coconut shell-derived steam-activated carbon powder present in range of 65%.
In an embodiment, the graphene in powder and fluffy form present in range of 10%.
In an embodiment, the conducting carbon in powder and fluffy form present in range of 20%.
In an embodiment, the carboxymethyl cellulose present in range of 5% in powder form act as a binder.
In an embodiment, the two liquid two liquid solvent comprises an isopropyl alcohol and a DI water.
In an embodiment, the isopropyl alcohol present in range of 50%.
In an embodiment, the DI water present in range of 50%.
In an aspect, the present invention provides a method of preparing electrode composition for supercapacitors comprising steps of:
7
a) mixing coconut shell-derived steam-activated carbon powder, graphene powder, conducting carbon powder and carboxymethyl cellulose powder in a ribbon mixer machine for 30 minutes;
b) transferring the mixture obtained in step (a) in a vacuum planetary mixer and adding two liquid solvents in equal percentage; and
c) mixing the mixture obtained in step (b) in the vacuum planetary mixer to obtain a slurry viscosity ranging from 3000 to 10000 centipoise (CPS).
In an embodiment, the slurry obtained from the composition and process of the present invention is used for coating and making electrode for the supercapacitors. The coating can be started either by applying it on etched Aluminium foil (20-40 microns thick), Formed Aluminium foil (16-27 microns thick), or Carbon-coated Aluminium foil (16 microns thick with a 1-micron conductive carbon coating on each sides). The slurry generated in the slurry production stage is applied to both sides of the chosen foil and then dried in an oven at temperatures ranging from 50 to 80°C. Subsequently, the coated foil is promptly transferred to a calendaring machine at 55°C, where it undergoes hot pressing on both sides to reach a final thickness of 200 to 220 microns. This resulting electrode material-coated foil, once cut to the desired size, is utilized as an electrode component in the assembly of supercapacitors.
In an embodiment, the electrode made by the slurry coating, the electrodes are shaped into disc forms and assembled into a 2032-coin cell configuration. This coin cell undergoes testing through cyclic Voltammetry and charge-discharge tests. The Cyclic Voltammogram results demonstrate exceptional EDLC behavior, as illustrated in Figure 3.
Further, the charge-discharge curve provides confirmation that the cell possesses an extraordinarily low internal resistance and delivers 80 Farads of capacitance per gram, as visually depicted in Figure 4.
In an embodiment, the slurry and its components stoichiometric / weight percent ratios t provides a homogeneous coating for high power supercapacitors. Coating that is not uniform in nature will reduce lifetime and prevent the cell from reaching the required supercapacitance value measured in Farad. In addition, the 80 F / g is the highest capacitance at the coin cell level.
8
In an embodiment, the slurry or electrode materials of the present invention provides advantages like enhanced energy density and improved capacity for energy storage. Further, it provides extended cycle life with increased durability and longevity of the supercapacitor.
In an embodiment, the slurry or electrode materials of the present invention provides high stability: Maintained performance over extended usage and Economical synthesis and manufacturing processes. , Claims:We Claim:
1.
An electrode composition for supercapacitors comprising:
a)
a coconut shell-derived steam-activated carbon powder;
b)
a graphene powder;
c)
a conducting carbon in powder;
d)
a carboxymethyl cellulose; and
e)
at least two liquid solvent presents in equal percentage.
2.
The electrode composition for supercapacitors as claimed in claim 1, wherein the coconut shell-derived steam-activated carbon powder present in range of 65%.
3.
The electrode composition for supercapacitors as claimed in claim 1, wherein the graphene in powder and fluffy form present in range of 10%.
4.
The electrode composition for supercapacitors as claimed in claim 1, wherein the conducting carbon in powder and fluffy form present in range of 20%.
5.
The electrode composition for supercapacitors as claimed in claim 1, wherein carboxymethyl cellulose present in range of 5% in powder form act as a binder.
6.
The electrode composition for supercapacitors as claimed in claim 1, wherein the two liquid two liquid solvent comprises an isopropyl alcohol and a DI water.
7.
The electrode composition for supercapacitors as claimed in claim 1, wherein the isopropyl alcohol present in range of 50%.
8.
The electrode composition for supercapacitors as claimed in claim 1, wherein the DI water present in range of 50%.
9.
A method of preparing electrode composition for supercapacitors comprising steps of:
a) mixing coconut shell-derived steam-activated carbon powder, graphene powder, conducting carbon powder and carboxymethyl cellulose powder in a ribbon mixer machine for 30 minutes;
b) transferring the mixture obtained in step (a) in a vacuum planetary mixer and adding two liquid solvents in equal percentage; and
c) mixing the mixture obtained in step (b) in the vacuum planetary mixer to obtain a slurry viscosity ranging from 3000 to 10000 centipoise (CPS).
10
10.
The method of preparing electrode composition for supercapacitors as claimed in claim 1, wherein the slurry serves as the electrode material for the fabrication of supercapacitors.