Description:FIELD OF THE INVENTION
[0001] The present disclosure relates to the field of electrochemical structures and energy storage devices. More particularly, the present disclosure provides a high-performance MoO₂-MoSe₂ heterostructure as anode materials for alkali metal-ion batteries such as lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). More specifically, the invention pertains to advanced anode materials for high-capacity, long-cycle-life rechargeable batteries.

BACKGROUND OF THE INVENTION
[0002] Background description 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.
[0003] In recent past, the rapid advancement of portable electronics, electric vehicles (EVs), and large-scale energy storage systems has drastically increased the demand for high-performance energy storage technologies. Among various energy storage solutions, lithium-ion batteries (LIBs) have become the most widely adopted technology due to their high energy density, long lifespan, and stable cycling performance. However, conventional LIBs still face several critical challenges that hinder their widespread applications.
[0004] The primary bottleneck in the current LIB systems is the low theoretical capacity of graphite anode (372 mAh g⁻¹), which severely limits the overall energy density of the batteries. Additionally, graphite anode suffers from slow lithium-ion diffusion kinetics, poor rate performance, and significant capacity degradation over extended cycles. As a result, there is a pressing need to explore alternative anode materials that can offer higher specific capacity, faster charge-discharge rates, and enhanced cycling stability.
[0005] To address these limitations, various materials such as transition metal oxides (TMOs), transition metal chalcogenides (TMCs), and hybrid nanostructures have been investigated as potential candidates for next-generation anodes. TMOs, including MoO₂, and Fe₂O₃, have demonstrated high theoretical capacities and robust structural stability. However, their poor electrical conductivity and sluggish charge transfer kinetics often result in low practical capacities and poor rate performance.
[0006] On the other hand, TMCs such as MoSe₂, WS₂, and SnSe₂ exhibit excellent electrical conductivity and fast ion diffusion pathways. Despite these advantages, TMCs alone typically suffer from large volume expansion, structural instability, and poor long-term cycling performance during repeated lithiation/delithiation or sodiation/desodiation processes.
[0007] Recent studies have shown that heterostructures which is a combination of TMOs and TMCs can potentially overcome the individual shortcomings of both material classes. By integrating two complementary materials, heterostructures can synergistically enhance the electrochemical performance through improved redox activity, faster charge transfer kinetics, and better structural stability. Despite these promising prospects, existing oxide-selenide heterostructures often suffer from complex fabrication processes, low yield, and inadequate electrochemical performance, making them impractical for commercial applications.
[0008] Therefore, there remains an urgent need to develop a scalable, cost-effective, and high-performance heterostructure anode material capable of delivering high capacity, fast charge-discharge rates, and long cycle life for alkali metal-ion batteries. The development of such advanced anode materials is essential to meet the growing energy demands of modern society, particularly for electric vehicles, grid-scale energy storage, and wearable electronics.

OBJECTIVE OF THE INVENTION
[0009] The primary objective of the present disclosure is to provide a novel MoO₂-MoSe₂ heterostructure as an anode material for alkali metal-ion batteries that overcomes the shortcomings of existing anode materials.
[0010] Another objective of the present invention is to provide a MoO₂-MoSe₂ heterostructure with high specific capacity with superior rate capability.
[0011] Another objective of the present invention is to provide a heterostructure with enhanced structural stability during prolonged charge-discharge cycles.
[0012] Another objective of the present invention is to provide a heterostructure with fast ion diffusion and excellent redox activity.
[0013] Another objective of the present invention is to provide a heterostructure with scalable and cost-effective fabrication process.
[0014] Another objective of the present invention is to provide a heterostructure with environmental friendliness and non-toxic precursor materials.
[0015] Another objective of the present invention is to provide a heterostructure with versatile applicability in both lithium-ion and sodium-ion batteries.
[0016] Another objective of the present invention is to provide a process for preparing the MoO₂-MoSe₂ heterostructures
[0017] Another objective of the present invention is to provide a lithium-ion battery and Sodium ion battery with high performances

SUMMARY OF THE INVENTION
[0018] The present disclosure encompasses a novel MoO₂-MoSe₂ heterostructure anode synthesized via a scalable hydrothermal process followed by annealing. The heterostructure combines the high theoretical capacity of MoO₂ with the excellent conductivity of MoSe₂, resulting in a synergistic improvement in electrochemical performance. The MoO₂-MoSe₂ heterostructure demonstrates remarkable specific capacity, rate capability, and cycling stability in both lithium-ion and sodium-ion battery systems. The optimized synthesis method ensures high yield and uniform morphology, making the material suitable for commercial applications.
[0019] In an aspect, the present disclosure provides an embodiment, the present disclosure provides a MoO₂-MoSe₂ heterostructure material comprising:
molybdenum dioxide (MoO₂), and
molybdenum diselenide (MoSe₂)
wherein said hetrostructure is synthesized through a hydrothermal method followed by annealing under an inert atmosphere.
[0020] In another embodiment, the present disclosure provides a process for preparing the MoO₂-MoSe₂ heterostructure, comprising the steps of:
dissolving Na₂MoO₄.2H₂O, Na₂SeO₃, and urea in a deionized water and ethanol mixture;
stirring the solution at 10,000 rpm for about 20 minutes to obtain homogeneity;
hydrothermal treatment at 200°C for 12 hours in a Teflon-lined autoclave;
washing and drying the resultant precipitate with DI water and ethanol in a vacuum oven overnight; and annealing at 300°C under argon atmosphere for 4 hours and dried in a vacuum oven overnight.
[0021] In an embodiment, the present disclosure provides a lithium-ion battery comprising:
MoO₂-MoSe₂ heterostructure as anode material;
lithium metal as the counter electrode;
a celgard separator; and
1M LiPF₆ electrolyte in ethylene carbonate (EC) and diethyl carbonate (DEC) solvent mixture.
[0022] In an embodiment, the present disclosure provides a sodium-ion battery comprising:
MoO₂-MoSe₂ heterostructure as anode material;
sodium metal as the counter electrode;
a glass fiber separator; and
1M NaPF₆ electrolyte in ethylene carbonate (EC) and diethyl carbonate (DEC) solvent mixture.
[0023] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments.

FIGURES OF THE INVENTION
[0024] FIG. 1 discloses Schematic of various steps adopted in the synthesis of the MoO2-MoSe2 heterostructure anode by hydrothermal method.
[0025] FIG. 2 discloses XRD pattern recorded for the MoO2-MoSe2 heterostructure.
[0026] FIG. 3 discloses (a) Cyclic voltammetry profile at 0.1 mV s-1, (b) galvanostatic charge-discharge profile at 0.02 C rate, (c) Rate capability data obtained at different C rates and (d) Cycle-life data as well as coulombic efficiency of the MoO2-MoSe2 heterostructure electrode in the lithium-ion half cell (MoO2-MoSe2|1M LiPF6|Li). (Inset: Initial discharge curve)
[0027] FIG. 4 discloses Galvanostatic charge–discharge profiles at 0.1C-rate recorded for the CR2032-type full cell lithium-ion battery (MoO2-MoSe2|1M LiPF6|LFP).
[0028] FIG. 5 discloses (a) Cyclic voltammetry profile at 0.1 mV s-1, (b) galvanostatic charge-discharge profile at 0.1 C rate, (c) Rate capability data obtained at different C rates and (d) Cycle-life data as well as coulombic efficiency of the MoO2-MoSe2 heterostructure electrode in the sodium-ion half cell (MoO2-MoSe2|1M NaPF6|Na). (Inset: Initial discharge curve)

DETAILED DESCRIPTION OF THE INVENTION
[0029] The following is a full description of the disclosure's embodiments. The embodiments are described in such a way that the disclosure is clearly communicated. The level of detail provided, on the other hand, is not meant to limit the expected variations of embodiments; rather, it is designed to include all modifications, equivalents, and alternatives that come within the spirit and scope of the current disclosure as defined by the attached claims. Unless the context indicates otherwise, the term "comprise" and variants such as "comprises" and "comprising" throughout the specification are to be read in an open, inclusive meaning, that is, as "including, but not limited to."
[0030] When "one embodiment" or "an embodiment" is used in this specification, it signifies that a particular feature, structure, or characteristic described in conjunction with the embodiment is present in at least one embodiment. As a result, the expressions "in one embodiment" and "in an embodiment" that appear throughout this specification do not necessarily refer to the same embodiment. Furthermore, in one or more embodiments, the specific features, structures, or qualities may be combined in any way that is appropriate.
[0031] Unless the content clearly demands otherwise, the singular terms "a," "an," and "the" include plural referents in this specification and the appended claims. Unless the content explicitly mandates differently, the term "or" is normally used in its broad definition, which includes "and/or."
[0032] All processes described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0033] The headings and abstract of the invention provided herein are for convenience only and do not interpret the scope or meaning of the embodiments.
[0034] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
[0035] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description that follows, and the embodiments described herein, is provided by way of illustration of an example, or examples, of particular embodiments of the principles and aspects of the present disclosure. These examples are provided for the purposes of explanation, and not of limitation, of those principles and of the disclosure.
[0036] It should also be appreciated that the present invention can be implemented in numerous ways, including as a system, a method or a device. In this specification, these implementations, or any other form that the invention may take, may be referred to as processes. In general, the order of the steps of the disclosed processes may be altered within the scope of the invention.
[0037] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.
Definitions:
[0038] For the purpose of the present invention, Anode may be defined an electrode at which oxidation occurs in an electrochemical cell.
[0039] For the purpose of the present invention, Cathode may be defined as an electrode at which reduction occurs in an electrochemical cell.
[0040] For the purpose of the present invention, Lithium-ion battery (LIB) may be defined as rechargeable battery technology that uses lithium ions as charge carriers.
[0041] For the purpose of the present invention, Sodium-ion battery (SIB) may be defined as rechargeable battery technology that uses sodium ions as charge carriers.
[0042] For the purpose of the present invention, Hydrothermal process may be defined as a synthesis method involving chemical reactions in aqueous solutions at elevated temperatures and pressures.
[0043] For the purpose of the present invention, Heterostructure may be defined as a composite structure composed of two or more different materials with distinct properties.
[0044] For the purpose of the present invention, Specific capacity may be defined as the amount of charge stored per unit mass of an electrode material.
[0045] For the purpose of the present invention, C-rate may be defined as a measure of the current rate at which a battery is charged or discharged.
[0046] For the purpose of the present invention, Redox reaction may be defined as a electrochemical reaction involving the transfer of electrons between two chemical species.
[0047] For the purpose of the present invention, Electrochemical stability may be defined as the ability of an electrode material to maintain its structure and performance over repeated charge-discharge cycles.
[0048] For the purpose of the present invention, Coulombic efficiency may be defined as the ratio of the total charge extracted from a battery to the total charge injected during charging.
[0049] For the purpose of the present invention, Volume expansion may be defined as the increase in volume of an electrode material during lithiation or sodiation.
[0050] For the purpose of the present invention, SEI layer may be defined as a Solid electrolyte interphase layer formed on the surface of an electrode during battery cycling.
[0051] For the purpose of the present invention, Cycling performance may be defined as the ability of a battery to retain its capacity over multiple charge-discharge cycles.
[0052] For the purpose of the present invention, Nanostructure may be defined as a material structure with dimensions in the nanometer scale.
[0053] For the purpose of the present invention, Crystallinity may be defined asthe degree of structural order in a material.
[0054] For the purpose of the present invention, Electrolyte may be defined as a medium that provides ionic conductivity in an electrochemical cell.
[0055] For the purpose of the present invention, Galvanostatic charge-discharge may be defined as a method of testing battery capacity by applying constant current during charge and discharge.
[0056] For the purpose of the present invention, Rate capability may be defined as the ability of an electrode material to deliver capacity at various charge-discharge rates.
[0057] For the purpose of the present invention, Argon atmosphere may be defined as an inert gas environment used during annealing to prevent oxidation.
[0058] In a general embodiment, the present invention relates to MoO₂-MoSe₂ heterostructure synthesized by a hydrothermal method followed by annealing under an argon atmosphere. The molar ratio of MoO₂ to MoSe₂ is optimized and standardized ensuring uniform distribution of both components. The resulting heterostructure exhibits nanoflower-like morphology, enhancing the active surface area and facilitating fast ion diffusion.
[0059] Electrochemical testing in lithium-ion and sodium-ion battery systems demonstrates that the MoO₂-MoSe₂ heterostructure achieves higher specific capacities in lithium-ion batteries and sodium-ion batteries. The heterostructure maintains high capacity retention over 500-700 cycles and delivers excellent rate capability even at high C-rates.
[0060] In an embodiment, the present disclosure provides a MoO₂-MoSe₂ heterostructure material comprising:
molybdenum dioxide (MoO₂), and
molybdenum diselenide (MoSe₂)
wherein said hetrostructure is synthesized through a hydrothermal method followed by annealing under an inert atmosphere.
[0061] In another embodiment, the molar ratio of MoO₂ to MoSe₂ ranges from 1:0.5 – 1:2, preferably 1:0.5; 1:1; 1:2.
[0062] In another embodiment, the capacity retention of said heterostructure ranges from 90 – 95 % after 500 charge-discharge cycles at a C-rate of 1 C.
[0063] In another embodiment, coulombic efficiency of said heterostructure is 99-100 % after the initial charge-discharge cycles.
[0064] In another embodiment, cycling stability of said heterostucture ranges between 85–98% of capacity retention over 500 charge-discharge cycles.
[0065] In another embodiment, the MoO₂-MoSe₂ heterostructure mitigates volume expansion effects, thereby reducing mechanical degradation, maintaining electrode integrity, stabilizing the SEI layer, and improving ion transport to enhances cycling stability and long-term durability in Li-ion battery.
[0066] In another embodiment, the heterostructure is in the form of nanoflower-like structures to enhance the active surface area and electrochemical performance.
[0067] In another embodiment, the heterostructure is coated with layers selected from carbon based materials selected from graphene, amorphous carbon, carbon nanotubes or a combination thereof to enhance electrical conductivity and mechanical stability.
[0068] In another embodiment, the present disclosure provides a process for preparing the MoO₂-MoSe₂ heterostructure, comprising the steps of:
dissolving Na₂MoO₄.2H₂O, Na₂SeO₃, and urea in a deionized water and ethanol mixture;
stirring the solution at 10,000 rpm for about 20 minutes to obtain homogeneity;
hydrothermal treatment at 200°C for 12 hours in a Teflon-lined autoclave;
washing and drying the resultant precipitate with DI water and ethanol in a vacuum oven overnight; and annealing at 300°C under argon atmosphere for 4 hours and dried in a vacuum oven overnight.
[0069] In an embodiment, a fixed amount of materials including Na₂MoO₄.2H₂O, Na₂SeO₃, and urea is taken in the synthesis according to the specified ratio. The material amount varies depending on the different ratios used.
[0070] In an embodiment, the hydrothermal synthesis is carried out at a temperature ranging from 180°C to 220°C to achieve uniform crystallinity and particle morphology.
[0071] In an embodiment, the morphology and crystallinity of said heterostructure are tuned by varying the annealing temperature between 200°C and 400°C.
[0072] In an embodiment, the annealing process is carried out in an argon or nitrogen atmosphere to prevent oxidation and enhance structural stability.
[0073] In an embodiment, the present disclosure provides a lithium-ion battery comprising:
MoO₂-MoSe₂ heterostructure as anode material;
lithium metal as the counter electrode;
a separator; and
1M LiPF₆ electrolyte in ethylene carbonate (EC) and diethyl carbonate (DEC) solvent mixture.
[0074] In an embodiment, the electrolyte composition comprises 1M LiPF₆ in ethylene carbonate (EC) and diethyl carbonate (DEC) (1:1 v/v).
[0075] In an embodiment, reversible capacity of said heterostructure ranges from 120 - 150 mAh g⁻¹ in full-cell lithium-ion batteries with LiFePO₄ cathodes.
[0076] In an embodiment, the present disclosure provides a sodium-ion battery comprising:
MoO₂-MoSe₂ heterostructure as anode material;
sodium metal as the counter electrode;
a glass fiber separator; and
1M NaPF₆ electrolyte in ethylene carbonate (EC) and diethyl carbonate (DEC) solvent mixture.
[0077] In an additional embodiment, any suitable component other 1M NaPF₆ in an EC:DEC combination can be used. Also, depending on the requirements and specific studies, different solvent combinations with varying molarity can also be used.
[0078] In an embodiment, the electrolyte composition comprises 1M NaPF₆ in ethylene carbonate (EC) and diethyl carbonate (DEC) (1:1 v/v).
[0079] In an additional embodiment, additives such as fluoroethylene carbonate (FEC), Vinylene Carbonate (VC) and Prop-1-ene-1,3-sultone (PES) can also be explored.
[0080] In an additional embodiment, the MoO₂-MoSe₂ heterostructure exhibits a synergistic effect that enhances the electrochemical performance by improving Specific capacity, Rate capability, Structural stability, and Cycling performance in both lithium-ion and sodium-ion batteries.
[0081] In an additional embodiment, the MoO₂-MoSe₂ heterostructure demonstrates superior rate capability at various C-rates without significant capacity degradation.
[0082] In an additional embodiment, the MoO₂-MoSe₂ heterostructure enhances redox activity at the oxide-selenide interface, minimizing volume expansion during charge-discharge cycles.
[0083] In an additional embodiment, the present disclosure provides a method of tuning the electrochemical performance of MoO₂-MoSe₂ heterostructure by varying the ratio of MoO₂ to MoSe₂ and controlling the morphology during the hydrothermal synthesis.
[0084] In an additional embodiment, MoO₂-MoSe₂ heterostructure may be used in flexible, solid-state batteries and other next-generation energy storage applications.
[0085] The present invention addresses the critical limitations of conventional anode materials by providing a novel MoO₂-MoSe₂ heterostructure with high specific capacity, excellent rate capability, and long-term cycling stability. The scalable synthesis process and superior electrochemical performance make the MoO₂-MoSe₂ heterostructure a promising candidate for next-generation lithium-ion and sodium-ion batteries. The invention contributes to the advancement of high-performance energy storage systems, meeting the growing demands of portable electronics, electric vehicles, and renewable energy integration.
[0086] While the foregoing describes various embodiments of the disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions, or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

EXAMPLES
[0087] The present invention is further explained in the form of the following examples. However, it is to be understood that the following examples are merely illustrative and are not to be taken as limitations upon the scope of the invention.

The Example 1: Synthesis of MoO₂-MoSe₂ Heterostructure
[0088] A solution containing 0.6 g of Na₂MoO₄.2H₂O, 0.45 g of Na₂SeO₃, and 0.15 g of urea was dissolved in a mixture of deionized water and ethanol (2:1 ratio) under constant magnetic stirring to obtain a homogeneous solution. The solution was then transferred into a Teflon-lined stainless steel autoclave and subjected to hydrothermal treatment at 200°C for 12 hours.
[0089] After cooling, the precipitate was collected by centrifugation, washed several times with deionized water and ethanol, and dried at 60°C under vacuum. The dried product was then annealed at 300°C for 4 hours under an argon atmosphere to obtain the final MoO₂-MoSe₂ heterostructure (Fig. 1).

Example 2: Structural Characterization
[0090] X-ray diffraction (XRD) patterns confirmed the successful formation of the MoO₂-MoSe₂ heterostructure. Scanning electron microscopy (SEM) revealed a nanoflower-like morphology, while transmission electron microscopy (TEM) showed a well-defined interface between MoO₂ and MoSe₂ (Fig. 2).

Example 3: Electrochemical Performance
[0091] CR-2032 coin cells were assembled with the heterostructure as the anode. The initial discharge capacity reached 2000 mAh g⁻¹ at 0.02 C-rate, with a capacity retention of 90% after 500 cycles at 1 C-rate (Fig. 3).

Example 4: Synthesis of MoO₂-MoSe₂ Heterostructure
[0092] A precursor solution consisting of 0.6 g Na₂MoO₄·2H₂O, 0.45 g Na₂SeO₃, and 0.15 g urea is dissolved in a mixture of deionized water and ethanol (2:1 ratio). The solution is stirred for 30 minutes and transferred into a Teflon-lined stainless steel autoclave. The autoclave is sealed and heated at 200°C for 12 hours. The resulting precipitate is collected, washed with deionized water and ethanol, and dried at 60°C (Fig. 4).

Example 4: Annealing Process
[0093] The dried precipitate is annealed at 300°C under an argon atmosphere for 4 hours to obtain the final MoO₂-MoSe₂ heterostructure. This annealing process improves the crystallinity and enhances the electrical conductivity of the heterostructure.

Example 6: Electrochemical Testing
[0094] CR-2032 coin cells are fabricated using the MoO₂-MoSe₂ heterostructure as the anode material, lithium metal as the counter electrode, and 1M LiPF₆ in EC/DEC (1:1) as the electrolyte. The cells are tested under galvanostatic charge-discharge cycling. The heterostructure delivers a specific capacity of 2007 mAh g⁻¹ at 0.02 C-rate and retains 90% capacity after 500 cycles at 1 C-rate (Fig. 5).

Example 7: Sodium-Ion Battery Testing
[0095] Half-cells are fabricated using the MoO₂-MoSe₂ heterostructure as the anode, sodium metal as the counter electrode, and 1M NaPF₆ in EC/DEC (1:1) as the electrolyte. The heterostructure achieves a specific capacity of 735 mAh g⁻¹ at 0.1 C-rate with excellent cycling stability.
[0096] Accordingly, the present invention addresses the critical limitations of conventional anode materials by providing a novel MoO₂-MoSe₂ heterostructure with high specific capacity, excellent rate capability, and long-term cycling stability.

ADVANTAGES OF THE PRESENT INVENTION
1. High Specific Capacity: The MoO₂-MoSe₂ heterostructure delivers significantly higher specific capacities compared to conventional graphite anodes, achieving up to 2000 mAh g⁻¹ in lithium-ion batteries and 735 mAh g⁻¹ in sodium-ion batteries.
2. Superior Rate Capability: The heterostructure demonstrates excellent performance at high C-rates, retaining 535 mAh g⁻¹ at 10 C-rate, making it suitable for high-power applications.
3. Enhanced Structural Stability: The synergistic effect between MoO₂ and MoSe₂ minimizes volume expansion, resulting in long cycle life and stable capacity retention over 500 cycles.
4. Fast Charge Transfer Kinetics: The combination of MoO₂ and MoSe₂ provides faster lithium-ion and sodium-ion diffusion due to their complementary electronic and ionic conductivity properties.
5. Scalable Fabrication Process: The hydrothermal synthesis method is cost-effective, environmentally friendly, and suitable for large-scale production.
6. Versatile Application: The heterostructure is compatible with both lithium-ion and sodium-ion batteries, offering flexible solutions for different energy storage systems.
7. Eco-Friendly Materials: The use of non-toxic precursors and environmentally benign synthesis methods makes the invention sustainable and green.
8. Potential for Solid-State Batteries: The material's excellent structural stability enables its integration into flexible, solid-state batteries for next-generation electronic.
, Claims:1. A MoO₂-MoSe₂ heterostructure anode material comprising:
molybdenum dioxide (MoO₂), and
molybdenum diselenide (MoSe₂)
wherein said hetrostructure is synthesized through a hydrothermal method followed by annealing under an inert atmosphere.
2. The MoO₂-MoSe₂ heterostructure as claimed in claim 1, wherein the molar ratio of MoO₂ to MoSe₂ ranges from 1:0.5 – 1:2, preferably 1:0.5; 1:1; 1:2.
3. The MoO₂-MoSe₂ heterostructure anode as claimed in claim 1, wherein the capacity retention of said heterostructure ranges from 90 – 95 % even upto 500 charge-discharge cycles at a C-rate of 1 C.
4. A process for preparing the MoO₂-MoSe₂ heterostructure, comprising the steps of:
dissolving Na₂MoO₄.2H₂O, Na₂SeO₃, and urea in a deionized water and ethanol mixture;
stirring the solution at 10,000 rpm for about 20 minutes to obtain homogeneity;
hydrothermal treatment at 200°C for 12 hours in a Teflon-lined autoclave;
washing and drying the resultant precipitate with DI water and ethanol in a vacuum oven overnight; and annealing at 300°C under argon atmosphere for 4 hours.
5. The MoO₂-MoSe₂ heterostructure as claimed in claim 4, wherein the hydrothermal synthesis is carried out at a temperature ranging from 180°C to 220°C to achieve uniform crystallinity and particle morphology.
6. The method as claimed in claim 5, wherein the morphology and crystallinity of said heterostructure are tuned in the annealing temperature range 200°C - 400°C.
7. The method as claimed in claim 5, wherein the annealing process is carried out in an argon or nitrogen atmosphere to enhance the structural stability.
8. A lithium-ion battery half-cell comprising:
MoO₂-MoSe₂ heterostructure as anode material;
lithium metal as the counter electrode;
a celgard separator; and
1M LiPF₆ electrolyte in ethylene carbonate (EC) and diethyl carbonate (DEC) solvent mixture.
wherein the electrolyte composition comprises 1M LiPF₆ in ethylene carbonate (EC) and diethyl carbonate (DEC) (1:1 v/v); and
wherein a high specific capacity of 1166 mAh g-1 at 1C-rate is achieved.
9. The lithium-ion battery full-cell is comprising of
MoO₂-MoSe₂ heterostructure as anode material;
Commercial Lithium-iron phosphate (LiFePO4 or LFP) as cathode;
a celgard separator; and
1M LiPF₆ electrolyte in ethylene carbonate (EC) and diethyl carbonate (DEC) solvent mixture.
wherein reversible capacity ranges from 120 - 150 mAh g⁻¹ at 0.1 C rate.
10. A sodium-ion half-cell battery comprising:
MoO₂-MoSe₂ heterostructure as anode material;
sodium metal as the counter electrode;
a glass fiber separator; and
1M NaPF₆ electrolyte in ethylene carbonate (EC) and diethyl carbonate (DEC) solvent mixture.
wherein the electrolyte composition comprises 1M NaPF₆ in ethylene carbonate (EC) and diethyl carbonate (DEC) (1:1 v/v); and
wherein a high specific capacity of 735 mAh g-1 at 0.1 C-rate is achieved.