FeSe2 AND N, S DOPED CARBON SPHERE MICRO FLOWER COMPOSITE AS A HIGH-PERFORMANCE ANODE MATERIAL FOR LITHIUM-ION BATTERY

Abstract

The present invention relates to an anodic material for use in lithium ion battery (LIB) comprising of FeSe.sub.2 and its carbon composite with N, S doped porous carbon spheres (PNSCS) which can be synthesised by hydrothermal route using iron ammonium sulphate, selenium powder and citric acid as precursors and used as an anode for LIB. Further, the invention provides a process for synthesizing the said FeSe.sub.2 a PNSCS micro-flower composite by simple hydrothermal route.

Claims

1. A composite comprising: FeSe.sub.2 with porous N and S-codoped carbon spheres PNSCS, wherein said FeSe.sub.2 is decorated onto said N and S-codoped carbon spheres PNSCS; wherein said composite is in the form of micro-flowers having a particle size in the range of 7 to 8 m.

2. The composite as claimed in claim 1, wherein the FeSe.sub.2 is wrapped over the surface of PNSCS with uniform distribution.

3. The composite as claimed in claim 1, wherein an amount of elemental carbon is 50-60 atomic %, an amount of elemental iron is 12-16 atomic %, and an amount of elemental selenium is 24-32 atomic % of the total composition of composite; and wherein an amount of elemental carbon is 15 to 20 wt. %, an amount of elemental iron is 15 to 25 wt. %, and an amount of elemental selenium is 55 to 65 wt. % of the total composition of composite.

4. The composite as claimed in claim 1, wherein the composite exhibits specific capacity of 350-450 mAhg.sup.1 after 1000 cycles at 1 Ag.sup.1.

5. The composite as claimed in claim 1, for use as an anode electrode in a Li ion battery.

6. A process for preparation of the composite as claimed in claim 1, comprising: a) stirring and dissolving sugar in a 1.sup.st solvent followed by addition of an amino acid; b) hydrothermally heating the solution of step a) at a temperature in a range of 160 to 200 C. for a time period of 20 to 26 hrs followed by cooling down the solution at a temperature of 25 to 30 C.; c) washing the solution of step b) with a 2.sup.nd solvent under a vacuum filtration followed by drying at a temperature in a range of 70-100 C. for a time period of 8 to 14 hrs; d) annealing the material of step c) at a temperature in a range of 780 to 820 C. for time a period of 1-1.30 hrs to obtain a N and S doped carbon spheres (NSCS); e) subjecting the NSCS of step d) with a KOH solution at a ratio in a range of 1:2 to 1:4 to obtain a mixture f) thermally treating the mixture of step e) at a temperature in a range of 780 to 820 C. with a ramp rate of 5 C. for a time period of 1 hr; g) cooling down the mixture of step f) at a temperature ranging from 25-30 C. followed by removing KOH through a filtration to obtain porous NSCS (PNSCS) particles; h) drying the PNSCS particles of step g) at a temperature in a range of 70-90 C. in an oven for a time period of 10-14 hrs; i) adding and stirring a mixture comprising an iron ammonium sulphate, a Se powder, a citric acid and said dried PNSCS of step h) in a 3.sup.rd solvent for a time period of 20 to 45 minutes; j) dropwise adding a hydrazine hydrate to the mixture of step i) under stirring for a time period of 20 to 40 minutes followed by sonication for a time period of 45 to 90 minutes; k) autoclaving the solution of step j) followed by heating at a temperature in a range of 160 to 200 C. for a time period of 10 to 14 hrs; and l) washing the solution of step k) with a 4.sup.th solvent to obtain a clear solution followed by drying the solution at a temperature in a range of 60 to 100 C. for a time period of 10 to 14 hrs to obtain the composite.

7. The process as claimed in claim 6, wherein the 1.sup.st, 2.sup.nd, 3.sup.rd and 4.sup.th solvents are independently selected from de-ionized water, ethanol or mixture thereof; and wherein the washing steps c) and l) is done by first treating with de-ionized water followed by a mixture of de-ionized water and ethanol.

8. The process as claimed in claim 6, wherein the amino acid is selected from L-cysteine, methionine, or alanine.

9. The process as claimed in claim 6, wherein the sugar in step a) is selected from saccharose, glucose, or fructose.

10. The process as claimed in claim 6, wherein a size of the FeSe.sub.2@PNSCS composite obtained is 7 to 8 m.

11. A full coin cell comprising: a) FeSe.sub.2@PNSCS as claimed in claim 1 as an anode; b) a cathode; c) a separator; d) an electrolyte; e) spring; f) spacer; and g) a metallic casing.

12. The full coin cell as claimed in claim 11, wherein the full coin cell has stability for up to 150-250 cycles at 0.1 C rate with a capacity value of 15-20 mAhg.sup.1.

13. The full coin cell as claimed claim 11, wherein the cell is a Li ion based battery.

14. The full coin cell as claimed claim 11, wherein the cathode is Lithium Iron phosphate (LiFePO.sub.4) or Lithium Cobalt Oxide (LiCoO.sub.2); the separator is Quartz fiber paper or Celgard 2500; and the electrolyte is selected from 1M LiPF.sub.6 in EC:DMC:EMC (1:1:1 by v/v/v) with 5% FEC, 1M LiPF.sub.6 in EC:DMC, and 1M LiPF.sub.6 in EC:DEC

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0062] FIG. 1: ESEM images for (a) FeSe.sub.2, (b) PNSCS, (c) and (d) FeSe.sub.2@PNSCS, and (e) illustrates EDX spectra for prepared FeSe.sub.2@PNSCS.

[0063] FIG. 2: demonstrates phase purity of as prepared FeSe.sub.2 and FeSe.sub.2@PNSCS micro-flower composites confirmed by p-XRD, where all peaks are well matching with FeSe.sub.2 JCPDS No. 79-1892 showing orthorhombic phase of FeSe.sub.2.

[0064] FIG. 3: LIB testing performance study of FeSe.sub.2@PNSCS in 1 M LiPF.sub.6 in EC/DMC with 5% FEC. (a) Cyclic voltammogram comparison for FeSe.sub.2 and FeSe.sub.2@PNSCS, (b) Rate performance study of FeSe.sub.2@PNSCS, (c) Cycling stability of FeSe.sub.2@PNSCS at 1 Ag.sup.1 and (d) cycling stability comparison of FeSe.sub.2 and FeSe.sub.2@PNSCS at 0.5 Ag.sup.1.

[0065] FIG. 4: Capacitive and diffusion-controlled contributions of FeSe.sub.2@PNSCS calculated from CV scans. (a) CV at different scan rates, (b) plot of log (current, i) vs log (scan rate, v), (c) i/v.sup.1/2 vs v.sup.1/2 and (d) normalized contribution ratio of capacitive and diffusion-controlled capacities at different scan rates.

[0066] FIG. 5: Li ion battery full cell comprised of FeSe.sub.2@PNSCS as anode and LiFePO.sub.4 as cathode. (a) Rate performance study and (b) Cycling stability at 0.1 C rate.

[0067] FIG. 6: A coin cell assembly with said FeSe.sub.2@PNSCS micro-flower composite as anode.

DETAILED DESCRIPTION OF THE INVENTION

[0068] The terms ferroselite or FeSe.sub.2 are used interchangeably throughout the specification, and the same means an orthorhombic-pyramidal mineral containing iron, magnesium, oxygen, and silicon; or an orthorhombic ferroselite and its isometric polymorph dzharkenite are iron selenides of general formula FeSe.sub.2 precipitated under reducing conditions in anoxic environments.

[0069] The expressions, ambient temperature and room temperature or rt as used herein, are understood in the art, and refer generally to a temperature, e.g. a reaction temperature, that is about the temperature of the room in which the reaction is carried out, for example, a temperature from about 20 C. to about 30 C.

[0070] Described herein is a FeSe.sub.2 and N. S doped porous carbon spheres (FeSe.sub.2@PNSCS) micro-flowers composite used as a high-performing anode material for Li-ion battery. The synthesis of said material is also described.

[0071] In an embodiment, the invention describes an Iron-based material which are beneficial for LIB, since iron is more abundant in nature, cost effective and environmentally friendly.

[0072] In an embodiment, the present invention provides a composite material comprising of a FeSe.sub.2 with N and S-doped porous carbon spheres, wherein the FeSe.sub.2 and N, S doped porous carbon spheres are formulated in the form of (FeSe.sub.2@PNSCS) micro-flowers composite having size of 7 m to 8 m.

[0073] In accordance with the above embodiment, the invention describes a FeSe.sub.2@PNSCS micro-flower composite anode which is used in Li-ion batteries for improved performance. Said anodic material is synthesised through a simple hydrothermal route and used as high energy anode material for lithium-ion batteries.

[0074] The FeSe.sub.2 micro-flowers have been synthesized by simple hydrothermal route and achieve high capacity of 702 mAhg.sup.1 at 500 mAg.sup.1 current density after 100 cycles. However, within 500 cycles bare FeSe.sub.2 shows degraded performance while capacity for FeSe.sub.2@PNSCS is much improved to 1329 mAhg.sup.1 after 500 cycles. This improved capacity is attributed to composite with CSs more particularly with N and S doped CSs. PNSCS provides conducting support to bare FeSe.sub.2 for charge and ionic transport. The doped carbon i.e. N and S doped carbon spheres support the conduction matrix for FeSe.sub.2 to avoid the capacity fading of bare FeSe.sub.2.

[0075] In another embodiment, the present invention provides a process for preparation of a FeSe.sub.2 and N, S doped porous carbon spheres (FeSe.sub.2@PNSCS) micro-flowers composite comprising steps of: [0076] 1) synthesis of a N and S doped CS [0077] a. stirring and dissolving 9-11 gm of sugar in a solvent followed by addition of 1-3 gm of an amino acid; [0078] b. hydrothermally heating the solution of step a) at temperature in range of 160 to 200 C. for time period of 20 to 26 hrs followed by cooling down the solution at temperature of 25-30 C.; [0079] c. washing the product of step b) with solvent under a vacuum filtration followed by drying at temperature in range of 70-100 C. for time period of 8 to 14 hrs; [0080] d. annealing the material of step c) at temperature in range of 780 to 820 C. in for 1-1.30 hrs to obtain 1-3 gm of N and S doped carbon spheres (NSCS); [0081] 2) synthesis of Porous NSCS [0082] e. subjecting the NSCS to a KOH solution with a ratio in the range of 1:2-1:4; [0083] f. thermally treating the mixture of step e) at temperature in range of 780 to 820 C. with ramp rate of 5 C. for 1 hr; [0084] g. cooling down the mixture of step f) at 25-30 C. followed by removing KOH through filtration to obtain porous NSCS (PNSCS) particles; [0085] h. drying the PNSCS at temperature in range of 70-90 C. in oven for 10-14 hrs; [0086] 3) synthesis of FeSe.sub.2@PNSCS composite: [0087] i. adding 0.6-0.8 gm of Iron ammonium sulphate, 0.2-0.4 gm of Se powder, 3-4 gm of a citric acid, and 100-150 mg of PNSCS (116 mg) as synthesized to 40-50 ml of solvent; [0088] j. stirring the mixture of step i) for time period of 20 to 45 minutes; [0089] k. dropwise adding 12-18 ml hydrazine hydrate to the mixture of step j) under stirring for 20 to 40 minutes followed by sonication for 45 to 90 minutes; [0090] l. autoclaving the solution of step k) followed by heating at temperature in the range of 160 to 200 C. for time period of 10 to 14 hrs; and [0091] m. washing with solvent to obtain a clear solution followed by drying the solution at temperature in the range of 60 to 100 C. for time period of 10 to 14 hrs.

[0092] In an embodiment of the present invention, the solvent used in step a) is selected from water ethanol or mixture thereof.

[0093] In an embodiment of the present invention, the amino acid is selected from L-cysteine, methionine, or alanine.

[0094] The solvent for washing in step c) is done by first washing with de-ionized water followed by second washing with ethanol.

[0095] In an embodiment of the present invention, the solvent used in step j) and n) is selected from DI water, or mixture of DI H.sub.2O and ethanol.

[0096] In an embodiment of the present invention, the size of composite FeSe.sub.2@PNSCS is 7-8 m. In an embodiment of the present invention, the FeSe.sub.2@PNSCS micro-flowers composite is used as an anode for Li-ion batteries.

[0097] In an embodiment of the present invention, the FeSe.sub.2@PNSCS micro-flowers composite exhibits specific capacity of 350-450 mAhg.sup.1 even after 1000 cycles.

[0098] In another embodiment of the present invention provides a full cell comprising of: FeSe.sub.2@PNSCS as claimed in claim 1 of the present invention as an anode, LiFePO.sub.4 as cathode, and wherein the full cell has shown stability for 200 cycles at 0.1 C rate with capacity value of 17 mAhg.sup.1.

[0099] In an embodiment of the present invention provides a battery comprising of FeSe.sub.2 and N, S doped porous carbon spheres (FeSe.sub.2@PNSCS) micro-flowers electrode as prepared from process given in the present disclosure.

[0100] In another aspect, the present invention relates to a full coin cell comprising: [0101] a) FeSe.sub.2@PNSCS [0102] b) a cathode, [0103] c) a separator, [0104] d) an electrolyte, [0105] e) spacer, [0106] f) spring, and [0107] e) metallic casing;
wherein the full cell has stability for up to 150-250 cycles at 0.1 C rate with capacity value of 15-20 mAhg.sup.1.

[0108] In another embodiment, the full coin cell is Li ion based battery cell.

[0109] In another embodiment, the cathode is Lithium Iron phosphate (LiFePO.sub.4) or Lithium Cobalt Oxide (LiCoO.sub.2).

[0110] In another embodiment, the separator is Quartz fiber paper or Celgard 2500.

[0111] In another embodiment, the electrolyte is selected from 1M LiPF.sub.6 in EC:DMC:EMC (1:1:1 by v/v/v) with 5% FEC, 1M LiPF.sub.6 in EC:DMC, and 1M LiPF.sub.6 in EC:DEC.

[0112] The metallic casing comprises positive casing and negative casing.

[0113] The negative and positive casings of the coin cell battery serve as negative and positive terminal of the battery and are made up of stainless steel. The negative case is equipped with sealant which ensures insulation from positive case.

[0114] The spring and spacer of said cell ensures proper packing of the coin cell.

[0115] The FIG. 6 shows the schematic of the full coin cell assembly. Negative case made up of stainless-steel acts as negative terminal. The lithium (LiFePO.sub.4) cathode is placed upon the negative case and Quartz fiber paper as a separator is kept above the anode with coating side of anode is facing the separator. The separator is wetted with the electrolyte. The anode is coated with said FeSe.sub.2@PNSCS composite and is in contact with separator and cathode on one side, and spacer on other side. The spacer and spring are then placed below to anode to ensure the tight packing of coin cell. Then positive case is placed above and the coin cell system is cold pressed using hydraulic press to give packed coin cells.

[0116] The electrochemical performance of FeSe.sub.2@PNSCS micro-flowers composite was studied 1 M LiPF.sub.6 in EC/DMC/EMC (1:1:1 by v/v/v) with 5% FEC cycling in potential range of 0.01-3 V in 2032-coin cell assembly. Upon composite making with PNSCS, FeSe.sub.2@PNSCS shows a slight increase in anodic and cathodic voltages indicating faster kinetics as compared to bare FeSe.sub.2. Also peak current values for FeSe.sub.2@PNSCS are higher than FeSe.sub.2 represents more charge transport resulting in higher capacity value for FeSe.sub.2@PNSCS.

[0117] The Porous nature and N. S dual-doped carbon spheres enhance the electronic conductivity and also provide binding sites for the facile deposition of a large number of FeSe.sub.2 micro-flowers. PNSCS provides the conducting channels for charge and ionic transport. As a result, FeSe.sub.2@PNSCS shows excellent rate performance and long cycle life.

[0118] The FeSe.sub.2 is used in a 1:1 ratio with porous N and S doped C spheres to form a composite. Performance of FeSe.sub.2 and composite is compared.

[0119] Though FeSe.sub.2 and the composite show 187 mAhg.sup.1 for current density of 1 Ag-1 and 443 mAhg.sup.1 for 2000 and 1000 cycles respectively, some prior arts report greater values, but at lower current density and for lower number of cycles.

[0120] FeSe.sub.2 micro-flowers are decorated over porous N and S doped carbon spheres. The composite of FeSe.sub.2 and PNSCS is synthesized using hydrothermal method. This hydrothermal method gives rise to micro-flower morphology. If synthesis method is changed, the morphology will also change.

[0121] FIG. 1 illustrates the scanning electron micrographs of micro-flower morphology for FeSe.sub.2. PNSCS and FeSe.sub.2 wrapped over the surface of PNSCS respectively. The composite FeSe.sub.2@PNSCS resulted into average size of 7-8 m. The uniform distribution of FeSe.sub.2 over PNSCS surface is attributed to the presence of N and S heteroatoms doping into CS. FIG. 2 demonstrates the pXRD spectra of FeSe.sub.2 and FeSe.sub.2@PNSCS. The observed peaks match with FeSe.sub.2 JCPDS No. 79-1892 showing orthorhombic phase of FeSe.sub.2. The XRD matches with JCPS, no impurity found, it is pure FeSe.sub.2. It is 1-2 microns in size and morphology appears like flowers. The charge-discharge cycles has been studied @160 cycles, increased capacity observed with gradual increase even if there's low current density. A detailed mechanistic explanation is provided for intermittent increase in capacity. FIG. 1(e) demonstrates EDX spectra for prepared FeSe.sub.2@PNSCS.

[0122] FIG. 3a illustrates the electrochemical performance of FeSe.sub.2@PNSCS micro-flowers composite studied as 1 M LiPF.sub.6 in EC/DMC/EMC (1:1:1 by v/v/v) with 5% FEC cycling in potential range of 0.01-3 V in 2032-coin cell assembly. Cyclic voltammograms of as prepared FeSe.sub.2 and FeSe.sub.2@PNSCS for at scan rate of 0.1 mVs.sup.1 in 0.01-3 V potential range. The two cathodic peaks observed in CV at 2 V and 1.5 V represents lithiation and conversion reactions of FeSe.sub.2@PNSCS. In subsequent charging to 3 V, two anodic peaks were observed in CV at 1.94 V and 2.29 V which represents the reverse delithiation of LiFeSe.sub.2 to form FeSe.sub.2. Upon composite making with PNSCS, FeSe.sub.2@PNSCS shows slight increase in anodic and cathodic voltages indicating faster kinetics as compared to bare FeSe.sub.2. Also peak current values for FeSe.sub.2@PNSCS are higher than FeSe.sub.2 indicating more charge transport, resulting in higher capacity value for FeSe.sub.2@PNSCS.

[0123] As illustrated in FIG. 3b, the rate performance is carried out at different current densities selected from 0.1 Ag.sup.1, 0.25 Ag.sup.1, 0.5 Ag.sup.1, 1 Ag.sup.1, 2 Ag.sup.1, 5 Ag.sup.1 and 0.1 Ag.sup.1 and capacity values observed were 550, 527, 514, 497, 488, 405 and 608 mAhg.sup.1 respectively. The stable capacity values at such different current rates make FeSe.sub.2@PNSCS a promising material as anode for LIB.

[0124] FIGS. 3c and 3d illustrates the long-term cycling of FeSe.sub.2@PNSCS at 0.5 Ag.sup.1 and 1 Ag.sup.1 current density. As can be seen from the FIG. 3c, the anodic material of the invention shows a long term stability of FeSe.sub.2@PNSCS at 1 Ag.sup.1 which shows increase in capacity for initial 250-300 cycles to a certain value and then a small decrease with further stability observed. Since the present material is conversion type one could easily predict partial formation and decomposition of SEI layer. The decomposition of SEI occurs due to catalytic property of metal particles formed during discharging process. Additionally, this increase in capacity for initial some cycle can be explained by opening of structure and giving more space for Li.sup.+ to accommodate into it while charging and discharging. At 1 Ag.sup.1 FeSe.sub.2@PNSCS exhibited specific capacity of 443 mAhg.sup.1 even after 1000 cycles.

[0125] FIG. 4 explains the electrochemical kinetics to find the reason for increased performance in FeSe.sub.2@PNSCS by calculating the capacitive and diffusive contribution to capacity by undertaking CV at different scan rates from 0.1-0.8 mVs.sup.1. For anodic peak at 2.2 V, capacitive contribution is 39%, 48%, 56%, 61%, and 64%, at 0.1, 0.2, 0.4, 0.6, and 0.8 mVs.sup.1 respectively which indicates dominance of surface controlled reaction as scan rate increases.

[0126] FIG. 5 shows a proof of concept model Li-ion battery full cell comprised of FeSe.sub.2@PNSCS as anode and LiFePO.sub.4 as cathode. Rate performance was carried out at 0.1 C, 0.2 C, 0.5 C, 1 C and 0.1 C current rates (1 C=165 mAg.sup.1) where capacity of 105, 74, 30, 8 and 82 mAhg.sup.1 were achieved at respective current values. The full cell has shown stability for 200 cycles at 0.1 C rate with capacity value of 17 mAhg.sup.1.

[0127] FIG. 6 is a representative figure of the present invention.

EXAMPLES

[0128] Following examples are given by way of illustration and therefore should not be construed to limit the scope of the invention.

Example 1: Synthesis of N, S Doped CS

[0129] The synthesis protocol is followed from one of our previously reported work where saccharose and L-cysteine in 5:1 ratio are used as precursors. 10 g of saccharose is first dissolved in 120 ml of de-ionized water followed by the addition of 2 g of L-cysteine under stirring. The resultant solution is then treated hydrothermally at 180 C. for 24 h. After cooling down to room temperature, the obtained product is washed several times with de-ionized water and ethanol by vacuum filtration followed by overnight drying at 80 C. After drying, the as-prepared material is annealed at 800 C. in an inert atmosphere for 1 h.

Example 2: Synthesis of PNSCS

[0130] The as prepared NSCS of Example 1 is subjected to KOH activation in which as prepared NSCS and KOH is taken in 1:3 ratio. The prepared mixture is thermally treated at 800 C. with ramp rate 5 C. in Ar atmosphere for 1 hr. After cooling down to room temperature KOH is removed using 1 M HCl through filtration. PNSCS is obtained after drying at 80 C. in oven for 12 hr.

Example 3: Synthesis of FeSe.SUB.2.@PNSCS Micro-Flowers

[0131] Iron ammonium sulphate (2 mmol), Se powder (4 mmol), citric acid (20.8 mmol) and PNSCS (116 mg) are added to 44 ml DI water and kept under stirring for half an hour. 16 ml hydrazine hydrate were added dropwise to the solution under stirring and kept this solution for half an hour stirring condition and then for 1 hour sonication. After vigorous stirring and sonication, the solution is transferred to 150 ml Teflon lined stainless steel autoclave and heated to 180 C. for 12 h. After cooling down to room temperature, solution is washed with DI water several times till a clear solution is obtained, to remove metallic Se and other impurities. Finally, the washed sample is dried at 80 C. for 12 h in oven.

Example 4

Material Characterization

[0132] As prepared FeSe.sub.2 phase was confirmed by powder X-ray diffraction that are carried out on a Philips X'Pert PRO diffractometer with nickel-filtered Cu K.sub. radiation (2=1.5418 ). The diffractograms were recorded at a scanning rate of 1 min.sup.1 between 10 to 80. The morphology of the material was established using a high-resolution field emission NOVA NANO SEM system.

Electrochemical Measurements:

[0133] The electrochemical testing of FeSe.sub.2 is done by making 2032-coin type half cells which were fabricated in Ar filled glove box. The working electrode is made by making homogeneous slurry of active material, conducting carbon and carboxyl methyl cellulose as binder in 70:20:10 wt % in NMP solvent. The slurry is coated on Cu foil and dried at 80 C. overnight. LiFePO.sub.4 cathode electrode for Full Cell is made by making homogeneous slurry of LiFePO.sub.4, conducting carbon and PVDF in 80:10:10 ratio wt % in NMP solvent. The slurry is coated on Al foil and dried at 80 C. overnight. Circular electrodes of 14 mm diameter sizes are cut down using electrode cutter. Mass balancing for anode and cathode is performed for full cell electrodes in 1:1 ratio. Li metal chip was used as counter/reference electrode and quartz fiber separator. 1 M LiPF.sub.6 in EC/DMC (1:1 V/V) with 5% FEC is used as electrolyte. The cyclic voltammetry and impedance studies are done by using Bio-Logic VMP3 instrument. Galvanostatic charge discharge measurements are carried out in MTI corporation battery analyser at variable current densities. The working potential for all electrochemical measurements are kept as 0.01-3 V.

Example 5

[0134] A comparative table for various literature reports and also specifically for Li ion battery performance is provided below.

TABLE-US-00001 TABLE 1 Current Sr. density Capacity No. Material (Ag.sup.1) (mAhg.sup.1) Cycles Ref 1. FeSe.sub.2CNT 0.5 571.2 50 Chem. Commun., 2019, 55, 10960-10963 DOI: 10.1039/ C9CC05069H 2. FeSe.sub.2@rGO 0.1 945.8 100 J Mater Sci 54, 4225-4235 (2019). DOI: 10.1007/ s10853-018- 3143-1 3. FeSe.sub.2@Fe.sub.2O.sub.3 1 770 1000 J. Mater. GC Chem. A, 2018, 6, 15182-15190 4. FeSe.sub.2 0.04 242 25 Int. J. nanoflowers Electrochem. Sci., Vol. 4, 2009 5. FeSe.sub.2C/rGO 0.1 917.6 100 Electrochimica Acta 323 (2019) 1348 6. FeSe.sub.2/C 0.1 798 100 ACS Appl. Mater. Interfaces2018, 10, 38862-38871 7. FeSe.sub.2@PNSCS 431 1 1000 Present invention

Advantages of the Invention

[0135] Lithium-ion battery (LIB) is most popular and well optimised to modern technology having high capacity with good cycling life. [0136] Further, Iron is more abundant in nature, cost effective and environmentally friendly. [0137] The FeSe.sub.2@PNSCS micro-flower composite anode of the invention anode improves Li-ion batteries performance. [0138] The present invention is based on the high performance anode material comprised of FeSe.sub.2@PNSCS composite for LIB application.