CN106816591A - A kind of preparation method of Graphene/lithium ferric phosphate/grapheme composite positive electrode material - Google Patents
A kind of preparation method of Graphene/lithium ferric phosphate/grapheme composite positive electrode material Download PDFInfo
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- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 272
- 229910021389 graphene Inorganic materials 0.000 title claims abstract description 268
- 239000002131 composite material Substances 0.000 title claims abstract description 93
- 239000007774 positive electrode material Substances 0.000 title claims abstract description 60
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 title claims abstract description 29
- 229910052744 lithium Inorganic materials 0.000 title claims abstract description 29
- 238000002360 preparation method Methods 0.000 title claims abstract description 29
- 239000005955 Ferric phosphate Substances 0.000 title claims abstract 13
- 229940032958 ferric phosphate Drugs 0.000 title claims abstract 13
- WBJZTOZJJYAKHQ-UHFFFAOYSA-K iron(3+) phosphate Chemical compound [Fe+3].[O-]P([O-])([O-])=O WBJZTOZJJYAKHQ-UHFFFAOYSA-K 0.000 title claims abstract 13
- 229910000399 iron(III) phosphate Inorganic materials 0.000 title claims abstract 13
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims abstract description 36
- PIICEJLVQHRZGT-UHFFFAOYSA-N Ethylenediamine Chemical compound NCCN PIICEJLVQHRZGT-UHFFFAOYSA-N 0.000 claims abstract description 34
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 claims abstract description 33
- 238000001027 hydrothermal synthesis Methods 0.000 claims abstract description 31
- IIPYXGDZVMZOAP-UHFFFAOYSA-N lithium nitrate Chemical compound [Li+].[O-][N+]([O-])=O IIPYXGDZVMZOAP-UHFFFAOYSA-N 0.000 claims abstract description 22
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 21
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims abstract description 18
- LFVGISIMTYGQHF-UHFFFAOYSA-N ammonium dihydrogen phosphate Chemical compound [NH4+].OP(O)([O-])=O LFVGISIMTYGQHF-UHFFFAOYSA-N 0.000 claims abstract description 15
- 229910000387 ammonium dihydrogen phosphate Inorganic materials 0.000 claims abstract description 15
- 235000019837 monoammonium phosphate Nutrition 0.000 claims abstract description 15
- VCJMYUPGQJHHFU-UHFFFAOYSA-N iron(3+);trinitrate Chemical compound [Fe+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O VCJMYUPGQJHHFU-UHFFFAOYSA-N 0.000 claims abstract description 14
- 235000003891 ferrous sulphate Nutrition 0.000 claims abstract description 11
- 239000011790 ferrous sulphate Substances 0.000 claims abstract description 11
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 claims abstract description 11
- 229910000359 iron(II) sulfate Inorganic materials 0.000 claims abstract description 11
- MCDLETWIOVSGJT-UHFFFAOYSA-N acetic acid;iron Chemical compound [Fe].CC(O)=O.CC(O)=O MCDLETWIOVSGJT-UHFFFAOYSA-N 0.000 claims abstract description 10
- XIXADJRWDQXREU-UHFFFAOYSA-M lithium acetate Chemical compound [Li+].CC([O-])=O XIXADJRWDQXREU-UHFFFAOYSA-M 0.000 claims abstract description 10
- 229910052742 iron Inorganic materials 0.000 claims abstract description 9
- 230000035484 reaction time Effects 0.000 claims abstract description 4
- 238000001354 calcination Methods 0.000 claims abstract 2
- 230000003197 catalytic effect Effects 0.000 claims abstract 2
- 238000000034 method Methods 0.000 claims description 26
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 24
- 229910052786 argon Inorganic materials 0.000 claims description 12
- 230000001681 protective effect Effects 0.000 claims description 12
- -1 lithium acetate Iron Chemical compound 0.000 claims description 10
- 229910019142 PO4 Inorganic materials 0.000 claims description 8
- 239000010452 phosphate Substances 0.000 claims description 8
- 238000003756 stirring Methods 0.000 claims description 7
- 239000012298 atmosphere Substances 0.000 claims description 3
- 239000003054 catalyst Substances 0.000 claims description 2
- 238000001338 self-assembly Methods 0.000 claims description 2
- 229910052493 LiFePO4 Inorganic materials 0.000 claims 5
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims 1
- 239000012300 argon atmosphere Substances 0.000 claims 1
- 210000000988 bone and bone Anatomy 0.000 claims 1
- 239000007789 gas Substances 0.000 claims 1
- 229910017604 nitric acid Inorganic materials 0.000 claims 1
- 230000014759 maintenance of location Effects 0.000 abstract description 11
- 230000004087 circulation Effects 0.000 abstract 1
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 description 163
- 239000000463 material Substances 0.000 description 43
- 239000002245 particle Substances 0.000 description 38
- 239000010406 cathode material Substances 0.000 description 34
- 239000000243 solution Substances 0.000 description 20
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 14
- 229910001416 lithium ion Inorganic materials 0.000 description 12
- 239000010450 olivine Substances 0.000 description 11
- 229910052609 olivine Inorganic materials 0.000 description 11
- 238000006555 catalytic reaction Methods 0.000 description 10
- 239000002994 raw material Substances 0.000 description 10
- 238000004458 analytical method Methods 0.000 description 9
- 239000011259 mixed solution Substances 0.000 description 9
- 239000000203 mixture Substances 0.000 description 9
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 9
- 239000004810 polytetrafluoroethylene Substances 0.000 description 9
- 238000001878 scanning electron micrograph Methods 0.000 description 9
- 238000001228 spectrum Methods 0.000 description 9
- 239000000126 substance Substances 0.000 description 9
- 238000005229 chemical vapour deposition Methods 0.000 description 6
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 6
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 5
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- MVFCKEFYUDZOCX-UHFFFAOYSA-N iron(2+);dinitrate Chemical compound [Fe+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O MVFCKEFYUDZOCX-UHFFFAOYSA-N 0.000 description 3
- 239000003575 carbonaceous material Substances 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000002243 precursor Substances 0.000 description 2
- 230000002441 reversible effect Effects 0.000 description 2
- 229910016870 Fe(NO3)3-9H2O Inorganic materials 0.000 description 1
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 1
- 229910012851 LiCoO 2 Inorganic materials 0.000 description 1
- 229910015643 LiMn 2 O 4 Inorganic materials 0.000 description 1
- 229910013553 LiNO Inorganic materials 0.000 description 1
- 229930006000 Sucrose Natural products 0.000 description 1
- CZMRCDWAGMRECN-UGDNZRGBSA-N Sucrose Chemical compound O[C@H]1[C@H](O)[C@@H](CO)O[C@@]1(CO)O[C@@H]1[C@H](O)[C@@H](O)[C@H](O)[C@@H](CO)O1 CZMRCDWAGMRECN-UGDNZRGBSA-N 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- ZTOZIUYGNMLJES-UHFFFAOYSA-K [Li+].[C+4].[Fe+2].[O-]P([O-])([O-])=O Chemical compound [Li+].[C+4].[Fe+2].[O-]P([O-])([O-])=O ZTOZIUYGNMLJES-UHFFFAOYSA-K 0.000 description 1
- 150000001336 alkenes Chemical class 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 238000004173 biogeochemical cycle Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 238000003837 high-temperature calcination Methods 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 239000005720 sucrose Substances 0.000 description 1
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- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/362—Composites
- H01M4/366—Composites as layered products
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
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- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
- H01M4/5825—Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
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- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
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- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
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- H01M4/625—Carbon or graphite
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Abstract
Description
技术领域technical field
本发明属于材料学领域，涉及锂电池领域，具体来说是一种石墨烯/磷酸铁锂/石墨烯复合正极材料的制备方法。The invention belongs to the field of materials science, relates to the field of lithium batteries, and specifically relates to a method for preparing a graphene/lithium iron phosphate/graphene composite cathode material.
背景技术Background technique
自从1997年，Goodenough等首次报道了具有橄榄石结构的磷酸铁锂可以用作锂电池以来，磷酸铁锂正极材料便引起了广泛的关注和大量的研究。磷酸铁锂具有170mAh/g的理论比容量和3.5V的对锂充电平台，与传统的LiCoO2 以及LiMn2O4 锂电池材料相比，具有原料来源广泛，成本低，无环境污染，循环性能好，热稳定性好，安全性能突出等优点，是动力型锂离子电池的理想正极材料。但因橄榄石结构的磷酸铁锂的电子导电率和离子传导率较差，在充放电时，锂离子的扩散系数很小，导致在室温下材料的可逆放电容量较小、循环性能较差。Since Goodenough et al first reported that lithium iron phosphate with an olivine structure could be used as a lithium battery in 1997, lithium iron phosphate cathode materials have attracted widespread attention and a lot of research. Lithium iron phosphate has a theoretical specific capacity of 170mAh/g and a 3.5V charging platform for lithium. Compared with traditional LiCoO 2 and LiMn 2 O 4 lithium battery materials, it has a wide range of raw material sources, low cost, no environmental pollution, and cycle performance Good thermal stability, outstanding safety performance and other advantages, it is an ideal cathode material for power lithium-ion batteries. However, due to the poor electronic conductivity and ionic conductivity of lithium iron phosphate with an olivine structure, the diffusion coefficient of lithium ions is very small during charge and discharge, resulting in a small reversible discharge capacity and poor cycle performance of the material at room temperature.
当前解决上述问题的途径主要是利用碳材料与磷酸铁锂复合制备碳-磷酸铁锂复合正极材料，以提高磷酸铁锂的导电性，进而提升材料的电化学性能。Adv. Mater. 2010,22, 4944–4948报道中利用介孔碳CMK-3为模板，将介孔碳CMK-3加入溶解有CH3COOLi：(CH3COO)2Fe：NH4H2PO4 = 1：1：1的溶液中，搅拌过夜，干燥，煅烧，最终得到介孔碳包裹磷酸铁锂的复合材料。该方法可制得电化学性能优良的材料，但是所用的介孔碳CMK-3制备过程繁琐，不合适工业化生产。The current way to solve the above problems is to use carbon materials and lithium iron phosphate composites to prepare carbon-lithium iron phosphate composite positive electrode materials to improve the conductivity of lithium iron phosphate, thereby improving the electrochemical performance of the material. Adv. Mater. 2010, 22 , 4944–4948 reported using mesoporous carbon CMK-3 as a template, adding mesoporous carbon CMK-3 into dissolved CH 3 COOLi: (CH3COO) 2 Fe: NH 4 H 2 PO 4 = 1:1:1 solution, stirred overnight, dried, and calcined to finally obtain a composite material of mesoporous carbon-wrapped lithium iron phosphate. This method can produce materials with excellent electrochemical properties, but the preparation process of the mesoporous carbon CMK-3 used is cumbersome and unsuitable for industrial production.
近来石墨烯复合材料引起广泛关注。石墨烯与传统碳材料相比具有更高的导电性，且石墨烯机械性能好、比表面积更大。石墨烯与磷酸铁锂复合有望进一步提高磷酸铁锂正极材料的性能。J. Mater. Chem. A, 2013, 1, 135–144报道中采用Fe(NO3)3·9H2O：NH4H2PO4： LiNO3 = 1：1：1.05加入水溶液中，加入蔗糖作为碳源，然后加入还原氧化石墨烯，超声2小时，烘干，高温煅烧得到石墨烯修饰的磷酸铁锂/（碳+还原氧化石墨烯）复合材料。该方法得到产品均匀性好，但是石墨烯对磷酸铁锂/碳的包裹作用只是物理混合作用。Recently, graphene composites have attracted extensive attention. Compared with traditional carbon materials, graphene has higher electrical conductivity, and graphene has better mechanical properties and larger specific surface area. The composite of graphene and lithium iron phosphate is expected to further improve the performance of lithium iron phosphate cathode material. J. Mater. Chem. A, 2013, 1, 135–144 reported that Fe(NO 3 ) 3 9H 2 O:NH 4 H 2 PO 4 : LiNO 3 = 1:1:1.05 was added to the aqueous solution, and sucrose was added As a carbon source, then add reduced graphene oxide, sonicate for 2 hours, dry, and calcinate at high temperature to obtain graphene-modified lithium iron phosphate/(carbon + reduced graphene oxide) composite material. This method has good product uniformity, but the wrapping effect of graphene on lithium iron phosphate/carbon is only a physical mixing effect.
发明内容：Invention content:
针对现有技术中的上述技术问题，本发明提供了一种石墨烯/磷酸铁锂/石墨烯复合正极材料的制备方法，所述的这种石墨烯/磷酸铁锂/石墨烯复合正极材料的制备方法要解决现有技术中锂离子电池中磷酸铁锂的电子导电率和离子传导率较差，在充放电时，锂离子的扩散系数很小，导致在室温下材料的可逆放电容量较小、循环性能较差的技术问题。In view of the above-mentioned technical problems in the prior art, the invention provides a kind of preparation method of graphene/lithium iron phosphate/graphene composite cathode material, the described this graphene/lithium iron phosphate/graphene composite cathode material The preparation method should solve the poor electronic conductivity and ion conductivity of lithium iron phosphate in the prior art, and the diffusion coefficient of lithium ions is very small during charge and discharge, resulting in a small reversible discharge capacity of the material at room temperature , Technical problems of poor cycle performance.
本发明提供了一种石墨烯/磷酸铁锂/石墨烯复合正极材料的制备方法，利用三维CVD石墨烯为骨架，利用氢氧化锂、硝酸锂、或者醋酸锂为锂源，硫酸亚铁、醋酸亚铁、或者硝酸铁为铁源，磷酸、或者磷酸二氢铵为磷酸根源，在乙二胺的催化作用下，进行水热反应，水热反应的温度为160℃-220℃，水热反应时间为8-16小时，然后再在400℃-800℃的温度下煅烧-8小时得到石墨烯/磷酸铁锂/石墨烯复合正极材料。The invention provides a preparation method of a graphene/lithium iron phosphate/graphene composite positive electrode material, using three-dimensional CVD graphene as a skeleton, using lithium hydroxide, lithium nitrate, or lithium acetate as a lithium source, ferrous sulfate, acetic acid Ferrous iron or ferric nitrate is the source of iron, and phosphoric acid or ammonium dihydrogen phosphate is the source of phosphate. Under the catalysis of ethylenediamine, a hydrothermal reaction is carried out. The temperature of the hydrothermal reaction is 160°C-220°C. The time is 8-16 hours, and then calcined at a temperature of 400° C.-800° C. for 8 hours to obtain a graphene/lithium iron phosphate/graphene composite positive electrode material.
进一步的，在锂源、铁源和磷酸根源中，锂元素、铁元素和磷酸根的摩尔比为1：1：1。Further, in the lithium source, the iron source and the phosphate source, the molar ratio of the lithium element, the iron element and the phosphate radical is 1:1:1.
进一步的，在所述的石墨烯/磷酸铁锂/石墨烯复合正极材料中，磷酸铁锂的质量百分比含量为70% - 90%，石墨烯的质量百分比含量为30% -10%。Further, in the graphene/lithium iron phosphate/graphene composite positive electrode material, the mass percentage content of lithium iron phosphate is 70%-90%, and the mass percentage content of graphene is 30%-10%.
进一步的，乙二胺和产物中磷酸铁锂的质量比为0.5-1:1。Further, the mass ratio of ethylenediamine to lithium iron phosphate in the product is 0.5-1:1.
进一步的，所述高温煅烧过程中使用氩气为保护气氛。Further, argon is used as a protective atmosphere during the high-temperature calcination process.
进一步的，本发明以氢氧化锂、硝酸锂、或者醋酸锂为锂源，硫酸亚铁、醋酸亚铁、或者硝酸铁为铁源，磷酸、或者磷酸二氢铵为磷酸根源，在氧化石墨烯溶液中按照锂元素、铁元素和磷酸根的摩尔比为1：1：1加入锂源、铁源和磷酸根源，搅拌至完全溶解，再加入三维CVD石墨烯骨架，然后加入乙二胺作为催化剂，在水热过程中反应得到三维自组装的石墨烯/磷酸铁锂/石墨烯前驱体，水热反应温度为160℃-220℃，水热反应时间为8-16小时，将制得的石墨烯/磷酸铁锂/石墨烯前驱体洗涤、干燥，放置于管式炉中，在氩气保护气氛下，400℃-800℃下煅烧2-8小时，制得三明治结构石墨烯/磷酸铁锂/石墨烯复合正极材料，其中，石墨烯在产物中的质量百分比含量30%-10%，磷酸铁锂在产物中的质量百分比含量为70% - 90%。Further, the present invention uses lithium hydroxide, lithium nitrate, or lithium acetate as the lithium source, ferrous sulfate, ferrous acetate, or ferric nitrate as the iron source, phosphoric acid, or ammonium dihydrogen phosphate as the phosphate source, and the graphene oxide Add lithium source, iron source and phosphate root into the solution according to the molar ratio of lithium element, iron element and phosphate root at 1:1:1, stir until completely dissolved, then add three-dimensional CVD graphene skeleton, and then add ethylenediamine as a catalyst , react in a hydrothermal process to obtain a three-dimensional self-assembled graphene/lithium iron phosphate/graphene precursor. The hydrothermal reaction temperature is 160°C-220°C, and the hydrothermal reaction time is 8-16 hours. The prepared graphite The alkene/lithium iron phosphate/graphene precursor is washed and dried, placed in a tube furnace, and calcined at 400°C-800°C for 2-8 hours under an argon protective atmosphere to obtain a sandwich-structured graphene/lithium iron phosphate /Graphene composite positive electrode material, wherein the mass percentage content of graphene in the product is 30%-10%, and the mass percentage content of lithium iron phosphate in the product is 70%-90%.
本发明使用三维CVD石墨烯作为磷酸铁锂的载体，在水热过程中氧化石墨烯微片将磷酸铁锂颗粒包裹在三维CVD石墨烯的表面。本发明有利于提高磷酸铁锂的导电性并改善材料的循环寿命。The present invention uses three-dimensional CVD graphene as a carrier of lithium iron phosphate, and graphene oxide microsheets wrap lithium iron phosphate particles on the surface of three-dimensional CVD graphene in a hydrothermal process. The invention is beneficial to improving the conductivity of the lithium iron phosphate and improving the cycle life of the material.
本发明和已有技术相比，其技术进步是显著的。本发明利用三维CVD（化学气相沉积）石墨烯作为骨架，具有良好的导电性，利于石墨烯性能的发挥。本发明采用一步水热法催化合成磷酸铁锂。本发明利用氧化石墨烯的自组装行为，可对磷酸铁锂颗粒进行较好的包裹，利于磷酸铁锂循环性能的发挥。测试表明，采用本发明合成的三明治结构石墨烯/磷酸铁锂/石墨烯复合正极材料，1C时放电比容量为150.9 mAh/g，50次循环后容量保持率为97.4%。通过本发明制备三明治结构石墨烯/磷酸铁锂/石墨烯复合正极材料，电化学性能优良，有望得到产业化应用。Compared with the prior art, the technical progress of the present invention is remarkable. The invention uses three-dimensional CVD (chemical vapor deposition) graphene as a skeleton, which has good electrical conductivity and is beneficial to the performance of graphene. The invention adopts a one-step hydrothermal method to catalyze and synthesize lithium iron phosphate. The invention uses the self-assembly behavior of graphene oxide to better wrap the lithium iron phosphate particles, which is beneficial to the performance of the lithium iron phosphate cycle performance. Tests show that the sandwich structure graphene/lithium iron phosphate/graphene composite positive electrode material synthesized by the present invention has a discharge specific capacity of 150.9 mAh/g at 1C, and a capacity retention rate of 97.4% after 50 cycles. The sandwich structure graphene/lithium iron phosphate/graphene composite positive electrode material prepared by the invention has excellent electrochemical performance and is expected to be applied industrially.
附图说明Description of drawings
图1为实施例1所制备的石墨烯/磷酸铁锂/石墨烯复合正极材料的XRD图。FIG. 1 is an XRD pattern of the graphene/lithium iron phosphate/graphene composite cathode material prepared in Example 1.
图2为实施例1所制备的石墨烯/磷酸铁锂/石墨烯复合正极材料的SEM图。2 is an SEM image of the graphene/lithium iron phosphate/graphene composite cathode material prepared in Example 1.
图3为实施例1所制备石墨烯/磷酸铁锂/石墨烯复合正极材料的1C充放电曲线。3 is the 1C charge-discharge curve of the graphene/lithium iron phosphate/graphene composite cathode material prepared in Example 1.
图4为实施例1所制备的石墨烯/磷酸铁锂/石墨烯复合正极材料1C循环性能图。4 is a 1C cycle performance diagram of the graphene/lithium iron phosphate/graphene composite positive electrode material prepared in Example 1.
具体实施方式detailed description
下面通过实施例并结合附图对本发明进行详细说明，但并不限制本发明。The present invention will be described in detail below by means of embodiments in conjunction with the accompanying drawings, but the present invention is not limited.
以下实施例采用的电化学性能测试条件为：电压范围2.5V～4.2V, 电解液为1MLiPF6/EC: DMC(1:1)。对电极为金属锂片，充放电电流为170mA/g(1C)，测试温度为20±2℃。The electrochemical performance test conditions adopted in the following examples are: the voltage range is 2.5V-4.2V, and the electrolyte is 1MLiPF 6 /EC:DMC (1:1). The counter electrode is a metal lithium sheet, the charge and discharge current is 170mA/g (1C), and the test temperature is 20 ± 2°C.
实施例1：Example 1:
一种三明治结构石墨烯/磷酸铁锂/石墨烯复合正极材料的制备方法，其制备所需的原料，按质量份数计算，其组成及用量如下：A method for preparing a sandwich structure graphene/lithium iron phosphate/graphene composite positive electrode material, the raw materials required for its preparation are calculated in parts by mass, and its composition and consumption are as follows:
氢氧化锂 7.6份Lithium hydroxide 7.6 parts
硫酸亚铁 50份50 parts of ferrous sulfate
磷酸 20.7份Phosphoric acid 20.7 parts
3mg/mL氧化石墨烯溶液 4000份3mg/mL graphene oxide solution 4000 parts
乙二胺 14.2份Ethylenediamine 14.2 parts
首先将氢氧化锂、硫酸亚铁和磷酸溶解于氧化石墨烯溶液中，再加入乙二胺，搅拌均匀。然后将混合液置于聚四氟乙烯反应釜中在220℃条件下水热反应12小时。在水热反应过程中，在乙二胺的催化作用下反应生成磷酸铁锂颗粒，同时氧化石墨烯微片进行自组装并将析出的磷酸铁锂颗粒紧密包裹在自组装的石墨烯片层间。随后将所得复合材料洗涤、干燥，然后在氩气保护下进行800℃热处理，热处理时间为6小时，制得三明治结构石墨烯/磷酸铁锂/石墨烯复合正极材料。Firstly, lithium hydroxide, ferrous sulfate and phosphoric acid are dissolved in the graphene oxide solution, then ethylenediamine is added, and stirred evenly. Then, the mixed solution was placed in a polytetrafluoroethylene reactor for hydrothermal reaction at 220° C. for 12 hours. During the hydrothermal reaction process, under the catalysis of ethylenediamine, lithium iron phosphate particles are reacted, and graphene oxide microsheets self-assemble and the precipitated lithium iron phosphate particles are tightly wrapped between the self-assembled graphene sheets. . Subsequently, the obtained composite material was washed and dried, and then heat-treated at 800° C. under the protection of argon for 6 hours to obtain a sandwich-structured graphene/lithium iron phosphate/graphene composite positive electrode material.
上述所得的三明治结构石墨烯/磷酸铁锂/石墨烯复合正极材料通过X射线衍射仪（TD-3200，丹东通达，Cu Kα）进行检测，所得的XRD测试结果如图1。图1中可以看出该图谱中所有的衍射峰都可以标定为橄榄石结构磷酸铁锂的衍射峰，没有其他物质的峰位出现，表明上述的石墨烯的含量并不影响磷酸铁锂的结构。进一步的分析表明，该石墨烯/磷酸铁锂/石墨烯复合正极材料中，磷酸铁锂的含量为70.3%，石墨烯的含量为29.7%。The sandwich structure graphene/lithium iron phosphate/graphene composite positive electrode material obtained above was detected by an X-ray diffractometer (TD-3200, Dandong Tongda, Cu Kα), and the obtained XRD test results are shown in Figure 1. It can be seen from Figure 1 that all the diffraction peaks in the spectrum can be calibrated as the diffraction peaks of olivine structure lithium iron phosphate, and no peak positions of other substances appear, indicating that the above-mentioned graphene content does not affect the structure of lithium iron phosphate . Further analysis shows that in the graphene/lithium iron phosphate/graphene composite cathode material, the content of lithium iron phosphate is 70.3%, and the content of graphene is 29.7%.
上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料，使用扫描电镜（SEM，日本电子6700F）所得的SEM图如图2所示。从图2中可以看出，所得的磷酸铁锂颗粒直径在100-200纳米之间，且被石墨烯较好的包裹，这种结构可以为材料提供导电网络从而提高材料的电导率，达到提高材料的电化学性能的目的。石墨烯包裹磷酸铁锂颗粒既提高其导电性，又起到相应的保护作用，可以提高材料的循环性能。The graphene/lithium iron phosphate/graphene composite positive electrode material obtained above is shown in FIG. 2 using a scanning electron microscope (SEM, JEOL 6700F). It can be seen from Figure 2 that the obtained lithium iron phosphate particles have a diameter between 100-200 nanometers and are well wrapped by graphene. This structure can provide a conductive network for the material to improve the electrical conductivity of the material and achieve The purpose of the electrochemical performance of the material. Graphene wrapping lithium iron phosphate particles not only improves its conductivity, but also plays a corresponding protective role, which can improve the cycle performance of the material.
将上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料，使用半电池方法组装成纽扣式2016电池在1C的倍率下对该电池的充放电性能进行测试，前5次充放电结果如图3所示，从图3中可以看出，该石墨烯/磷酸铁锂/石墨烯电池正极材料在1C倍率下的放电比容量为150.9 mAh/g。电池在1C倍率下进行充放电循环性能测试，如图4所示，50次循环后其容量为147 mAh/g，容量保持率97.4%。由此表明，本发明所得的石墨烯/磷酸铁锂/石墨烯电池正极材料具有较高的质量比容量和良好的循环稳定性，将可以在锂离子电池领域应用。The graphene/lithium iron phosphate/graphene composite positive electrode material obtained above was assembled into a button-type 2016 battery using the half-cell method. The charge-discharge performance of the battery was tested at a rate of 1C. The results of the first 5 charge-discharge cycles are shown in the figure 3, it can be seen from Figure 3 that the discharge specific capacity of the graphene/lithium iron phosphate/graphene battery cathode material at 1C rate is 150.9 mAh/g. The battery was tested for charge-discharge cycle performance at 1C rate, as shown in Figure 4, after 50 cycles, its capacity was 147 mAh/g, and the capacity retention rate was 97.4%. This shows that the graphene/lithium iron phosphate/graphene battery positive electrode material obtained in the present invention has higher mass specific capacity and good cycle stability, and will be applicable in the field of lithium ion batteries.
实施例2：Example 2:
一种石墨烯/磷酸铁锂/石墨烯复合正极材料的制备方法，其制备所需的原料，按质量份数计算，其组成及用量如下：A preparation method of graphene/lithium iron phosphate/graphene composite cathode material, the raw materials required for its preparation are calculated in parts by mass, and its composition and consumption are as follows:
硝酸锂 14.5份Lithium nitrate 14.5 parts
硝酸铁 84.8份84.8 parts of ferric nitrate
磷酸 24.2份Phosphoric acid 24.2 parts
3mg/mL氧化石墨烯溶液 4000份3mg/mL graphene oxide solution 4000 parts
乙二胺 16.6份Ethylenediamine 16.6 parts
首先将硝酸锂、硝酸铁和磷酸溶解于氧化石墨烯溶液中，再加入乙二胺，搅拌均匀。然后将混合液置于聚四氟乙烯反应釜中在170℃条件下水热反应10小时。在水热反应过程中，在乙二胺的催化作用下反应生成磷酸铁锂颗粒，同时氧化石墨烯微片进行自组装并将析出的磷酸铁锂颗粒紧密包裹在自组装的石墨烯片层间。随后将所得复合材料洗涤、干燥，然后在氩气保护下进行500℃热处理，热处理时间为4小时，制得石墨烯/磷酸铁锂/石墨烯复合正极材料。First, lithium nitrate, iron nitrate and phosphoric acid are dissolved in the graphene oxide solution, then ethylenediamine is added, and stirred evenly. Then the mixed solution was placed in a polytetrafluoroethylene reactor for hydrothermal reaction at 170° C. for 10 hours. During the hydrothermal reaction process, under the catalysis of ethylenediamine, lithium iron phosphate particles are reacted, and graphene oxide microsheets self-assemble and the precipitated lithium iron phosphate particles are tightly wrapped between the self-assembled graphene sheets. . Subsequently, the obtained composite material was washed and dried, and then heat-treated at 500° C. under the protection of argon for 4 hours to obtain a graphene/lithium iron phosphate/graphene composite positive electrode material.
上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料通过X射线衍射仪（TD-3200，丹东通达，Cu Kα）进行检测，所得的XRD测试结果与图1相似。图谱中所有的衍射峰都也可以标定为橄榄石结构磷酸铁锂的衍射峰，没有其他物质的峰位出现，表明上述的石墨烯的含量并不影响磷酸铁锂的结构。进一步的分析表明，该石墨烯/磷酸铁锂/石墨烯复合正极材料中，磷酸铁锂的含量为73.6%，石墨烯的含量为26.4%。The graphene/lithium iron phosphate/graphene composite cathode material obtained above was detected by an X-ray diffractometer (TD-3200, Dandong Tongda, Cu Kα), and the obtained XRD test results were similar to those shown in Figure 1. All the diffraction peaks in the spectrum can also be calibrated as the diffraction peaks of olivine structure lithium iron phosphate, and no peak positions of other substances appear, indicating that the above-mentioned graphene content does not affect the structure of lithium iron phosphate. Further analysis shows that in the graphene/lithium iron phosphate/graphene composite positive electrode material, the content of lithium iron phosphate is 73.6%, and the content of graphene is 26.4%.
上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料，使用扫描电镜（SEM，日本电子6700F）所得的SEM图与图2相似。所得的磷酸铁锂颗粒直径在100-200纳米之间，且被石墨烯较好的包裹，这种结构可以为材料提供导电网络从而提高材料的电导率，达到提高材料的电化学性能的目的。石墨烯包裹磷酸铁锂颗粒既提高其导电性，又起到相应的保护作用，可以提高材料的循环性能。The graphene/lithium iron phosphate/graphene composite positive electrode material obtained above is similar to FIG. 2 in the SEM image obtained by using a scanning electron microscope (SEM, JEOL 6700F). The obtained lithium iron phosphate particles have a diameter of 100-200 nanometers and are well wrapped by graphene. This structure can provide a conductive network for the material to improve the electrical conductivity of the material and achieve the purpose of improving the electrochemical performance of the material. Graphene wrapping lithium iron phosphate particles not only improves its conductivity, but also plays a corresponding protective role, which can improve the cycle performance of the material.
将上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料，使用半电池方法组装成纽扣式2016电池在1C的倍率下对该电池的充放电性能进行测试，放电比容量为150 mAh/g，50次循环后其容量为146.3 mAh/g，容量保持率97.5%。由此表明，本发明所得的石墨烯/磷酸铁锂/石墨烯电池正极材料具有较高的质量比容量和良好的循环稳定性，将可以在锂离子电池领域应用。The graphene/lithium iron phosphate/graphene composite cathode material obtained above was assembled into a button-type 2016 battery using the half-cell method. The charge and discharge performance of the battery was tested at a rate of 1C, and the discharge specific capacity was 150 mAh/g , the capacity after 50 cycles is 146.3 mAh/g, and the capacity retention rate is 97.5%. This shows that the graphene/lithium iron phosphate/graphene battery positive electrode material obtained in the present invention has higher mass specific capacity and good cycle stability, and will be applicable in the field of lithium ion batteries.
实施例3：Example 3:
一种石墨烯/磷酸铁锂/石墨烯复合正极材料的制备方法，其制备所需的原料，按质量份数计算，其组成及用量如下：A preparation method of graphene/lithium iron phosphate/graphene composite cathode material, the raw materials required for its preparation are calculated in parts by mass, and its composition and consumption are as follows:
醋酸锂 16.5份Lithium acetate 16.5 parts
醋酸亚铁 43.5份43.5 parts of ferrous acetate
磷酸 28.8份Phosphoric acid 28.8 parts
3mg/mL氧化石墨烯溶液 4000份3mg/mL graphene oxide solution 4000 parts
乙二胺 19.4份Ethylenediamine 19.4 parts
首先将醋酸锂、醋酸亚铁和磷酸溶解于氧化石墨烯溶液中，再加入乙二胺，搅拌均匀。然后将混合液置于聚四氟乙烯反应釜中在160℃条件下水热反应8小时。在水热反应过程中，在乙二胺的催化作用下反应生成磷酸铁锂颗粒，同时氧化石墨烯微片进行自组装并将析出的磷酸铁锂颗粒紧密包裹在自组装的石墨烯片层间。随后将所得复合材料洗涤、干燥，然后在氩气保护下进行38.60℃热处理，热处理时间为2小时，制得石墨烯/磷酸铁锂/石墨烯复合正极材料。First, dissolve lithium acetate, ferrous acetate and phosphoric acid in the graphene oxide solution, then add ethylenediamine, and stir evenly. Then the mixed solution was placed in a polytetrafluoroethylene reactor for hydrothermal reaction at 160° C. for 8 hours. During the hydrothermal reaction process, under the catalysis of ethylenediamine, lithium iron phosphate particles are reacted, and graphene oxide microsheets self-assemble and the precipitated lithium iron phosphate particles are tightly wrapped between the self-assembled graphene sheets. . Subsequently, the obtained composite material was washed and dried, and then heat-treated at 38.60° C. under the protection of argon for 2 hours to obtain a graphene/lithium iron phosphate/graphene composite positive electrode material.
上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料通过X射线衍射仪（TD-3200，丹东通达，Cu Kα）进行检测，所得的XRD测试结果与图1相似。图谱中所有的衍射峰都可以标定为橄榄石结构磷酸铁锂的衍射峰，没有其他物质的峰位出现，表明上述的石墨烯的含量并不影响磷酸铁锂的结构。进一步的分析表明，该石墨烯/磷酸铁锂/石墨烯复合正极材料中，磷酸铁锂的含量为76.4%，石墨烯的含量为23.6%。The graphene/lithium iron phosphate/graphene composite cathode material obtained above was detected by an X-ray diffractometer (TD-3200, Dandong Tongda, Cu Kα), and the obtained XRD test results were similar to those shown in Figure 1. All the diffraction peaks in the spectrum can be calibrated as the diffraction peaks of olivine structure lithium iron phosphate, and no peak positions of other substances appear, indicating that the above-mentioned graphene content does not affect the structure of lithium iron phosphate. Further analysis shows that in the graphene/lithium iron phosphate/graphene composite cathode material, the content of lithium iron phosphate is 76.4%, and the content of graphene is 23.6%.
上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料，使用扫描电镜（SEM，日本电子6700F）所得的SEM图与图2相似。所得的磷酸铁锂颗粒直径在100-200纳米之间，且被石墨烯较好的包裹，这种结构可以为材料提供导电网络从而提高材料的电导率，达到提高材料的电化学性能的目的。石墨烯包裹磷酸铁锂颗粒既提高其导电性，又起到相应的保护作用，可以提高材料的循环性能。The graphene/lithium iron phosphate/graphene composite positive electrode material obtained above is similar to FIG. 2 in the SEM image obtained by using a scanning electron microscope (SEM, JEOL 6700F). The obtained lithium iron phosphate particles have a diameter of 100-200 nanometers and are well wrapped by graphene. This structure can provide a conductive network for the material to improve the electrical conductivity of the material and achieve the purpose of improving the electrochemical performance of the material. Graphene wrapping lithium iron phosphate particles not only improves its conductivity, but also plays a corresponding protective role, which can improve the cycle performance of the material.
将上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料，使用半电池方法组装成纽扣式2016电池在1C的倍率下对该电池的充放电性能进行测试，放电比容量为149.7 mAh/g，50次循环后其容量为145.6 mAh/g，容量保持率97.3%。由此表明，本发明所得的石墨烯/磷酸铁锂/石墨烯电池正极材料具有较高的质量比容量和良好的循环稳定性，将可以在锂离子电池领域应用。The graphene/lithium iron phosphate/graphene composite cathode material obtained above was assembled into a button-type 2016 battery using the half-cell method. The charge and discharge performance of the battery was tested at a rate of 1C, and the discharge specific capacity was 149.7 mAh/g , the capacity after 50 cycles is 145.6 mAh/g, and the capacity retention rate is 97.3%. This shows that the graphene/lithium iron phosphate/graphene battery positive electrode material obtained in the present invention has higher mass specific capacity and good cycle stability, and will be applicable in the field of lithium ion batteries.
实施例4：Example 4:
一种石墨烯/磷酸铁锂/石墨烯复合正极材料的制备方法，其制备所需的原料，按质量份数计算，其组成及用量如下：A preparation method of graphene/lithium iron phosphate/graphene composite cathode material, the raw materials required for its preparation are calculated in parts by mass, and its composition and consumption are as follows:
氢氧化锂 16.4份Lithium hydroxide 16.4 parts
硫酸亚铁 108.4份108.4 parts of ferrous sulfate
磷酸二氢铵 44.9份Ammonium dihydrogen phosphate 44.9 parts
3mg/mL氧化石墨烯溶液 4000份3mg/mL graphene oxide solution 4000 parts
乙二胺 30.6份30.6 parts of ethylenediamine
首先将氢氧化锂、硫酸亚铁和磷酸二氢铵溶解于氧化石墨烯溶液中，再加入乙二胺，搅拌均匀。然后将混合液置于聚四氟乙烯反应釜中在220℃条件下水热反应16小时。在水热反应过程中，在乙二胺的催化作用下反应生成磷酸铁锂颗粒，同时氧化石墨烯微片进行自组装并将析出的磷酸铁锂颗粒紧密包裹在自组装的石墨烯片层间。随后将所得复合材料洗涤、干燥，然后在氩气保护下进行800℃热处理，热处理时间为8小时，制得石墨烯/磷酸铁锂/石墨烯复合正极材料。First, dissolve lithium hydroxide, ferrous sulfate and ammonium dihydrogen phosphate in the graphene oxide solution, then add ethylenediamine, and stir evenly. Then, the mixed solution was placed in a polytetrafluoroethylene reactor for hydrothermal reaction at 220° C. for 16 hours. During the hydrothermal reaction process, under the catalysis of ethylenediamine, lithium iron phosphate particles are reacted, and graphene oxide microsheets self-assemble and the precipitated lithium iron phosphate particles are tightly wrapped between the self-assembled graphene sheets. . Subsequently, the obtained composite material was washed and dried, and then heat-treated at 800° C. under the protection of argon for 8 hours to obtain a graphene/lithium iron phosphate/graphene composite positive electrode material.
上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料通过X射线衍射仪（TD-3200，丹东通达，Cu Kα）进行检测，所得的XRD测试结果与图1相似。图谱中所有的衍射峰都可以标定为橄榄石结构磷酸铁锂的衍射峰，没有其他物质的峰位出现，表明上述的石墨烯的含量并不影响磷酸铁锂的结构。进一步的分析表明，该石墨烯/磷酸铁锂/石墨烯复合正极材料中，磷酸铁锂的含量为83.6%，石墨烯的含量为16.4%。The graphene/lithium iron phosphate/graphene composite cathode material obtained above was detected by an X-ray diffractometer (TD-3200, Dandong Tongda, Cu Kα), and the obtained XRD test results were similar to those shown in Figure 1. All the diffraction peaks in the spectrum can be calibrated as the diffraction peaks of olivine structure lithium iron phosphate, and no peak positions of other substances appear, indicating that the above-mentioned graphene content does not affect the structure of lithium iron phosphate. Further analysis shows that in the graphene/lithium iron phosphate/graphene composite cathode material, the content of lithium iron phosphate is 83.6%, and the content of graphene is 16.4%.
上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料，使用扫描电镜（SEM，日本电子6700F）所得的SEM图与图2相似。所得的磷酸铁锂颗粒直径在100-200纳米之间，且被石墨烯较好的包裹，这种结构可以为材料提供导电网络从而提高材料的电导率，达到提高材料的电化学性能的目的。石墨烯包裹磷酸铁锂颗粒既提高其导电性，又起到相应的保护作用，可以提高材料的循环性能。The graphene/lithium iron phosphate/graphene composite positive electrode material obtained above is similar to FIG. 2 in the SEM image obtained by using a scanning electron microscope (SEM, JEOL 6700F). The obtained lithium iron phosphate particles have a diameter of 100-200 nanometers and are well wrapped by graphene. This structure can provide a conductive network for the material to improve the electrical conductivity of the material and achieve the purpose of improving the electrochemical performance of the material. Graphene wrapping lithium iron phosphate particles not only improves its conductivity, but also plays a corresponding protective role, which can improve the cycle performance of the material.
将上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料，使用半电池方法组装成纽扣式2016电池在1C的倍率下对该电池的充放电性能进行测试，放电比容量为149.2 mAh/g，50次循环后其容量为145 mAh/g，容量保持率97.2%。由此表明，本发明所得的石墨烯/磷酸铁锂/石墨烯电池正极材料具有较高的质量比容量和良好的循环稳定性，将可以在锂离子电池领域应用。The graphene/lithium iron phosphate/graphene composite cathode material obtained above was assembled into a button-type 2016 battery using the half-cell method. The charge and discharge performance of the battery was tested at a rate of 1C, and the discharge specific capacity was 149.2 mAh/g , the capacity after 50 cycles is 145 mAh/g, and the capacity retention rate is 97.2%. This shows that the graphene/lithium iron phosphate/graphene battery positive electrode material obtained in the present invention has higher mass specific capacity and good cycle stability, and will be applicable in the field of lithium ion batteries.
实施例5：Example 5:
一种石墨烯/磷酸铁锂/石墨烯复合正极材料的制备方法，其制备所需的原料，按质量份数计算，其组成及用量如下：A preparation method of graphene/lithium iron phosphate/graphene composite cathode material, the raw materials required for its preparation are calculated in parts by mass, and its composition and consumption are as follows:
醋酸锂 44.2份Lithium acetate 44.2 parts
醋酸亚铁 116.5份116.5 parts of ferrous acetate
磷酸二氢铵 77.1份Ammonium dihydrogen phosphate 77.1 parts
3mg/mL氧化石墨烯溶液 4000份3mg/mL graphene oxide solution 4000 parts
乙二胺 52.3份Ethylenediamine 52.3 parts
首先将醋酸锂、醋酸亚铁和磷酸二氢铵溶解于氧化石墨烯溶液中，再加入乙二胺，搅拌均匀。然后将混合液置于聚四氟乙烯反应釜中在180℃条件下水热反应11小时。在水热反应过程中，在乙二胺的催化作用下反应生成磷酸铁锂颗粒，同时氧化石墨烯微片进行自组装并将析出的磷酸铁锂颗粒紧密包裹在自组装的石墨烯片层间。随后将所得复合材料洗涤、干燥，然后在氩气保护下进行700℃热处理，热处理时间为3小时，制得石墨烯/磷酸铁锂/石墨烯复合正极材料。First, dissolve lithium acetate, ferrous acetate and ammonium dihydrogen phosphate in the graphene oxide solution, then add ethylenediamine, and stir evenly. Then the mixed solution was placed in a polytetrafluoroethylene reactor for hydrothermal reaction at 180° C. for 11 hours. During the hydrothermal reaction process, under the catalysis of ethylenediamine, lithium iron phosphate particles are reacted, and graphene oxide microsheets self-assemble and the precipitated lithium iron phosphate particles are tightly wrapped between the self-assembled graphene sheets. . Subsequently, the obtained composite material was washed and dried, and then heat-treated at 700° C. under the protection of argon for 3 hours to obtain a graphene/lithium iron phosphate/graphene composite positive electrode material.
上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料通过X射线衍射仪（TD-3200，丹东通达，Cu Kα）进行检测，所得的XRD测试结果与图1相似。图谱中所有的衍射峰都可以标定为橄榄石结构磷酸铁锂的衍射峰，没有其他物质的峰位出现，表明上述的石墨烯的含量并不影响磷酸铁锂的结构。进一步的分析表明，该石墨烯/磷酸铁锂/石墨烯复合正极材料中，磷酸铁锂的含量为89.7%，石墨烯的含量为10.3%。The graphene/lithium iron phosphate/graphene composite cathode material obtained above was detected by an X-ray diffractometer (TD-3200, Dandong Tongda, Cu Kα), and the obtained XRD test results were similar to those shown in Figure 1. All the diffraction peaks in the spectrum can be calibrated as the diffraction peaks of olivine structure lithium iron phosphate, and no peak positions of other substances appear, indicating that the above-mentioned graphene content does not affect the structure of lithium iron phosphate. Further analysis shows that in the graphene/lithium iron phosphate/graphene composite positive electrode material, the content of lithium iron phosphate is 89.7%, and the content of graphene is 10.3%.
上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料，使用扫描电镜（SEM，日本电子6700F）所得的SEM图与图2相似。所得的磷酸铁锂颗粒直径在100-200纳米之间，且被石墨烯较好的包裹，这种结构可以为材料提供导电网络从而提高材料的电导率，达到提高材料的电化学性能的目的。石墨烯包裹磷酸铁锂颗粒既提高其导电性，又起到相应的保护作用，可以提高材料的循环性能。The graphene/lithium iron phosphate/graphene composite positive electrode material obtained above is similar to FIG. 2 in the SEM image obtained by using a scanning electron microscope (SEM, JEOL 6700F). The obtained lithium iron phosphate particles have a diameter of 100-200 nanometers and are well wrapped by graphene. This structure can provide a conductive network for the material to improve the electrical conductivity of the material and achieve the purpose of improving the electrochemical performance of the material. Graphene wrapping lithium iron phosphate particles not only improves its conductivity, but also plays a corresponding protective role, which can improve the cycle performance of the material.
将上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料，使用半电池方法组装成纽扣式2016电池在1C的倍率下对该电池的充放电性能进行测试，放电比容量为148.5 mAh/g，50次循环后其容量为144.2 mAh/g，容量保持率97.1%。由此表明，本发明所得的石墨烯/磷酸铁锂/石墨烯电池正极材料具有较高的质量比容量和良好的循环稳定性，将可以在锂离子电池领域应用。The graphene/lithium iron phosphate/graphene composite positive electrode material obtained above was assembled into a button-type 2016 battery using the half-cell method. The charge and discharge performance of the battery was tested at a rate of 1C, and the discharge specific capacity was 148.5 mAh/g , the capacity after 50 cycles is 144.2 mAh/g, and the capacity retention rate is 97.1%. This shows that the graphene/lithium iron phosphate/graphene battery positive electrode material obtained in the present invention has higher mass specific capacity and good cycle stability, and will be applicable in the field of lithium ion batteries.
实施例6：Embodiment 6:
一种石墨烯/磷酸铁锂/石墨烯复合正极材料的制备方法，其制备所需的原料，按质量份数计算，其组成及用量如下：A preparation method of graphene/lithium iron phosphate/graphene composite cathode material, the raw materials required for its preparation are calculated in parts by mass, and its composition and consumption are as follows:
硝酸锂 29.6份Lithium nitrate 29.6 parts
硝酸铁 173.7份173.7 parts of ferric nitrate
磷酸二氢铵 49.5份Ammonium dihydrogen phosphate 49.5 parts
3mg/mL氧化石墨烯溶液 4000份3mg/mL graphene oxide solution 4000 parts
乙二胺 34份Ethylenediamine 34 parts
首先将硝酸锂、硝酸铁和磷酸二氢铵溶解于氧化石墨烯溶液中，再加入乙二胺，搅拌均匀。然后将混合液置于聚四氟乙烯反应釜中在190℃条件下水热反应9小时。在水热反应过程中，在乙二胺的催化作用下反应生成磷酸铁锂颗粒，同时氧化石墨烯微片进行自组装并将析出的磷酸铁锂颗粒紧密包裹在自组装的石墨烯片层间。随后将所得复合材料洗涤、干燥，然后在氩气保护下进行600℃热处理，热处理时间为5小时，制得石墨烯/磷酸铁锂/石墨烯复合正极材料。First, dissolve lithium nitrate, iron nitrate and ammonium dihydrogen phosphate in the graphene oxide solution, then add ethylenediamine, and stir evenly. Then, the mixed solution was placed in a polytetrafluoroethylene reactor for hydrothermal reaction at 190° C. for 9 hours. During the hydrothermal reaction process, under the catalysis of ethylenediamine, lithium iron phosphate particles are reacted, and graphene oxide microsheets self-assemble and the precipitated lithium iron phosphate particles are tightly wrapped between the self-assembled graphene sheets. . Subsequently, the obtained composite material was washed and dried, and then heat-treated at 600° C. under the protection of argon for 5 hours to obtain a graphene/lithium iron phosphate/graphene composite positive electrode material.
上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料通过X射线衍射仪（TD-3200，丹东通达，Cu Kα）进行检测，所得的XRD测试结果与图1相似。图谱中所有的衍射峰都可以标定为橄榄石结构磷酸铁锂的衍射峰，没有其他物质的峰位出现，表明上述的石墨烯的含量并不影响磷酸铁锂的结构。进一步的分析表明，该石墨烯/磷酸铁锂/石墨烯复合正极材料中，磷酸铁锂的含量为85%，石墨烯的含量为15%。The graphene/lithium iron phosphate/graphene composite cathode material obtained above was detected by an X-ray diffractometer (TD-3200, Dandong Tongda, Cu Kα), and the obtained XRD test results were similar to those shown in Figure 1. All the diffraction peaks in the spectrum can be calibrated as the diffraction peaks of olivine structure lithium iron phosphate, and no peak positions of other substances appear, indicating that the above-mentioned graphene content does not affect the structure of lithium iron phosphate. Further analysis shows that in the graphene/lithium iron phosphate/graphene composite positive electrode material, the content of lithium iron phosphate is 85%, and the content of graphene is 15%.
上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料，使用扫描电镜（SEM，日本电子6700F）所得的SEM图与图2相似。所得的磷酸铁锂颗粒直径在100-200纳米之间，且被石墨烯较好的包裹，这种结构可以为材料提供导电网络从而提高材料的电导率，达到提高材料的电化学性能的目的。石墨烯包裹磷酸铁锂颗粒既提高其导电性，又起到相应的保护作用，可以提高材料的循环性能。The graphene/lithium iron phosphate/graphene composite positive electrode material obtained above is similar to FIG. 2 in the SEM image obtained by using a scanning electron microscope (SEM, JEOL 6700F). The obtained lithium iron phosphate particles have a diameter of 100-200 nanometers and are well wrapped by graphene. This structure can provide a conductive network for the material to improve the electrical conductivity of the material and achieve the purpose of improving the electrochemical performance of the material. Graphene wrapping lithium iron phosphate particles not only improves its conductivity, but also plays a corresponding protective role, which can improve the cycle performance of the material.
将上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料，使用半电池方法组装成纽扣式2016电池在1C的倍率下对该电池的充放电性能进行测试，放电容量为149.1 mAh/g，50次循环后其容量为145.8 mAh/g，容量保持率97.8%。由此表明，本发明所得的石墨烯/磷酸铁锂/石墨烯电池正极材料具有较高的质量比容量和良好的循环稳定性，将可以在锂离子电池领域应用。The graphene/lithium iron phosphate/graphene composite positive electrode material obtained above was assembled into a button-type 2016 battery using a half-cell method. The charge and discharge performance of the battery was tested at a rate of 1C, and the discharge capacity was 149.1 mAh/g. After 50 cycles, its capacity is 145.8 mAh/g, and the capacity retention rate is 97.8%. This shows that the graphene/lithium iron phosphate/graphene battery positive electrode material obtained in the present invention has higher mass specific capacity and good cycle stability, and will be applicable in the field of lithium ion batteries.
实施例7：Embodiment 7:
一种石墨烯/磷酸铁锂/石墨烯复合正极材料的制备方法，其制备所需的原料，按质量份数计算，其组成及用量如下：A preparation method of graphene/lithium iron phosphate/graphene composite cathode material, the raw materials required for its preparation are calculated in parts by mass, and its composition and consumption are as follows:
氢氧化锂 21.8份Lithium hydroxide 21.8 parts
醋酸亚铁 90.4份Ferrous acetate 90.4 parts
磷酸 60份Phosphoric acid 60 parts
3mg/mL氧化石墨烯溶液 4000份3mg/mL graphene oxide solution 4000 parts
乙二胺 40.5份Ethylenediamine 40.5 parts
首先将氢氧化锂、醋酸亚铁和磷酸溶解于氧化石墨烯溶液中，再加入乙二胺，搅拌均匀。然后将混合液置于聚四氟乙烯反应釜中在200℃条件下水热反应12小时。在水热反应过程中，在乙二胺的催化作用下反应生成磷酸铁锂颗粒，同时氧化石墨烯微片进行自组装并将析出的磷酸铁锂颗粒紧密包裹在自组装的石墨烯片层间。随后将所得复合材料洗涤、干燥，然后在氩气保护下进行500℃热处理，热处理时间为6小时，制得石墨烯/磷酸铁锂/石墨烯复合正极材料。Firstly, lithium hydroxide, ferrous acetate and phosphoric acid are dissolved in the graphene oxide solution, then ethylenediamine is added, and stirred evenly. Then, the mixed solution was placed in a polytetrafluoroethylene reactor for hydrothermal reaction at 200° C. for 12 hours. During the hydrothermal reaction process, under the catalysis of ethylenediamine, lithium iron phosphate particles are reacted, and graphene oxide microsheets self-assemble and the precipitated lithium iron phosphate particles are tightly wrapped between the self-assembled graphene sheets. . Subsequently, the obtained composite material was washed and dried, and then heat-treated at 500° C. under the protection of argon for 6 hours to obtain a graphene/lithium iron phosphate/graphene composite positive electrode material.
上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料通过X射线衍射仪（TD-3200，丹东通达，Cu Kα）进行检测，所得的XRD测试结果与图1相似。图谱中所有的衍射峰都可以标定为橄榄石结构磷酸铁锂的衍射峰，没有其他物质的峰位出现，表明上述的石墨烯的含量并不影响磷酸铁锂的结构。进一步的分析表明，该石墨烯/磷酸铁锂/石墨烯复合正极材料中，磷酸铁锂的含量为87.1%，石墨烯的含量为12.9%。The graphene/lithium iron phosphate/graphene composite cathode material obtained above was detected by an X-ray diffractometer (TD-3200, Dandong Tongda, Cu Kα), and the obtained XRD test results were similar to those shown in Figure 1. All the diffraction peaks in the spectrum can be calibrated as the diffraction peaks of olivine structure lithium iron phosphate, and no peak positions of other substances appear, indicating that the above-mentioned graphene content does not affect the structure of lithium iron phosphate. Further analysis shows that in the graphene/lithium iron phosphate/graphene composite positive electrode material, the content of lithium iron phosphate is 87.1%, and the content of graphene is 12.9%.
上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料，使用扫描电镜（SEM，日本电子6700F）所得的SEM图与图2相似。所得的磷酸铁锂颗粒直径在100-200纳米之间，且被石墨烯较好的包裹，这种结构可以为材料提供导电网络从而提高材料的电导率，达到提高材料的电化学性能的目的。石墨烯包裹磷酸铁锂颗粒既提高其导电性，又起到相应的保护作用，可以提高材料的循环性能。The graphene/lithium iron phosphate/graphene composite positive electrode material obtained above is similar to FIG. 2 in the SEM image obtained by using a scanning electron microscope (SEM, JEOL 6700F). The obtained lithium iron phosphate particles have a diameter of 100-200 nanometers and are well wrapped by graphene. This structure can provide a conductive network for the material to improve the electrical conductivity of the material and achieve the purpose of improving the electrochemical performance of the material. Graphene wrapping lithium iron phosphate particles not only improves its conductivity, but also plays a corresponding protective role, which can improve the cycle performance of the material.
将上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料，使用半电池方法组装成纽扣式2016电池在1C的倍率下对该电池的充放电性能进行测试，放电容量为148.7 mAh/g，50次循环后其容量为144 mAh/g，容量保持率97%。由此表明，本发明所得的石墨烯/磷酸铁锂/石墨烯电池正极材料具有较高的质量比容量和良好的循环稳定性，将可以在锂离子电池领域应用。The graphene/lithium iron phosphate/graphene composite cathode material obtained above was assembled into a button-type 2016 battery using a half-cell method. The charge-discharge performance of the battery was tested at a rate of 1C, and the discharge capacity was 148.7 mAh/g. After 50 cycles, its capacity is 144 mAh/g, and the capacity retention rate is 97%. This shows that the graphene/lithium iron phosphate/graphene battery positive electrode material obtained in the present invention has higher mass specific capacity and good cycle stability, and will be applicable in the field of lithium ion batteries.
实施例8：Embodiment 8:
一种石墨烯/磷酸铁锂/石墨烯复合正极材料的制备方法，其制备所需的原料，按质量份数计算，其组成及用量如下：A preparation method of graphene/lithium iron phosphate/graphene composite cathode material, the raw materials required for its preparation are calculated in parts by mass, and its composition and consumption are as follows:
醋酸锂 24.4份Lithium acetate 24.4 parts
硝酸铁 149.5份149.5 parts of ferric nitrate
磷酸二氢铵 42.6份Ammonium dihydrogen phosphate 42.6 parts
3mg/mL氧化石墨烯溶液 4000份3mg/mL graphene oxide solution 4000 parts
乙二胺 28.7份Ethylenediamine 28.7 parts
首先将醋酸锂、硝酸铁和磷酸二氢铵溶解于氧化石墨烯溶液中，再加入乙二胺，搅拌均匀。然后将混合液置于聚四氟乙烯反应釜中在210℃条件下水热反应13小时。在水热反应过程中，在乙二胺的催化作用下反应生成磷酸铁锂颗粒，同时氧化石墨烯微片进行自组装并将析出的磷酸铁锂颗粒紧密包裹在自组装的石墨烯片层间。随后将所得复合材料洗涤、干燥，然后在氩气保护下进行600℃热处理，热处理时间为7小时，制得石墨烯/磷酸铁锂/石墨烯复合正极材料。Firstly, lithium acetate, iron nitrate and ammonium dihydrogen phosphate are dissolved in the graphene oxide solution, then ethylenediamine is added, and stirred evenly. Then the mixed solution was placed in a polytetrafluoroethylene reactor for hydrothermal reaction at 210° C. for 13 hours. During the hydrothermal reaction process, under the catalysis of ethylenediamine, lithium iron phosphate particles are reacted, and graphene oxide microsheets self-assemble and the precipitated lithium iron phosphate particles are tightly wrapped between the self-assembled graphene sheets. . Subsequently, the obtained composite material was washed and dried, and then heat-treated at 600° C. under the protection of argon for 7 hours to obtain a graphene/lithium iron phosphate/graphene composite positive electrode material.
上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料通过X射线衍射仪（TD-3200，丹东通达，Cu Kα）进行检测，所得的XRD测试结果与图1相似。图谱中所有的衍射峰都可以标定为橄榄石结构磷酸铁锂的衍射峰，没有其他物质的峰位出现，表明上述的石墨烯的含量并不影响磷酸铁锂的结构。进一步的分析表明，该石墨烯/磷酸铁锂/石墨烯复合正极材料中，磷酸铁锂的含量为82.7%，石墨烯的含量为17.3%。The graphene/lithium iron phosphate/graphene composite cathode material obtained above was detected by an X-ray diffractometer (TD-3200, Dandong Tongda, Cu Kα), and the obtained XRD test results were similar to those shown in Figure 1. All the diffraction peaks in the spectrum can be calibrated as the diffraction peaks of olivine structure lithium iron phosphate, and no peak positions of other substances appear, indicating that the above-mentioned graphene content does not affect the structure of lithium iron phosphate. Further analysis shows that in the graphene/lithium iron phosphate/graphene composite positive electrode material, the content of lithium iron phosphate is 82.7%, and the content of graphene is 17.3%.
上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料，使用扫描电镜（SEM，日本电子6700F）所得的SEM图与图2相似。所得的磷酸铁锂颗粒直径在100-200纳米之间，且被石墨烯较好的包裹，这种结构可以为材料提供导电网络从而提高材料的电导率，达到提高材料的电化学性能的目的。石墨烯包裹磷酸铁锂颗粒既提高其导电性，又起到相应的保护作用，可以提高材料的循环性能。The graphene/lithium iron phosphate/graphene composite positive electrode material obtained above is similar to FIG. 2 in the SEM image obtained by using a scanning electron microscope (SEM, JEOL 6700F). The obtained lithium iron phosphate particles have a diameter of 100-200 nanometers and are well wrapped by graphene. This structure can provide a conductive network for the material to improve the electrical conductivity of the material and achieve the purpose of improving the electrochemical performance of the material. Graphene wrapping lithium iron phosphate particles not only improves its conductivity, but also plays a corresponding protective role, which can improve the cycle performance of the material.
将上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料，使用半电池方法组装成纽扣式2016电池在1C的倍率下对该电池的充放电性能进行测试，放电容量为149 mAh/g，50次循环后其容量为144.3 mAh/g，容量保持率96.8%。由此表明，本发明所得的石墨烯/磷酸铁锂/石墨烯电池正极材料具有较高的质量比容量和良好的循环稳定性，将可以在锂离子电池领域应用。The graphene/lithium iron phosphate/graphene composite positive electrode material obtained above was assembled into a button-type 2016 battery using a half-cell method. The charge and discharge performance of the battery was tested at a rate of 1C, and the discharge capacity was 149 mAh/g. After 50 cycles, its capacity is 144.3 mAh/g, and the capacity retention rate is 96.8%. This shows that the graphene/lithium iron phosphate/graphene battery positive electrode material obtained in the present invention has higher mass specific capacity and good cycle stability, and will be applicable in the field of lithium ion batteries.
实施例9：Embodiment 9:
一种石墨烯/磷酸铁锂/石墨烯复合正极材料的制备方法，其制备所需的原料，按质量份数计算，其组成及用量如下：A preparation method of graphene/lithium iron phosphate/graphene composite cathode material, the raw materials required for its preparation are calculated in parts by mass, and its composition and consumption are as follows:
硝酸锂 19.3份Lithium nitrate 19.3 parts
硫酸亚铁 77.8份77.8 parts of ferrous sulfate
磷酸二氢铵 32.2份Ammonium dihydrogen phosphate 32.2 parts
3mg/mL氧化石墨烯溶液 4000份3mg/mL graphene oxide solution 4000 parts
乙二胺 21.7份Ethylenediamine 21.7 parts
首先将硝酸锂、硫酸亚铁和磷酸二氢铵溶解于氧化石墨烯溶液中，再加入乙二胺，搅拌均匀。然后将混合液置于聚四氟乙烯反应釜中在180℃条件下水热反应15小时。在水热反应过程中，在乙二胺的催化作用下反应生成磷酸铁锂颗粒，同时氧化石墨烯微片进行自组装并将析出的磷酸铁锂颗粒紧密包裹在自组装的石墨烯片层间。随后将所得复合材料洗涤、干燥，然后在氩气保护下进行700℃热处理，热处理时间为5小时，制得石墨烯/磷酸铁锂/石墨烯复合正极材料。First, dissolve lithium nitrate, ferrous sulfate and ammonium dihydrogen phosphate in the graphene oxide solution, then add ethylenediamine, and stir evenly. Then the mixed solution was placed in a polytetrafluoroethylene reactor for hydrothermal reaction at 180° C. for 15 hours. During the hydrothermal reaction process, under the catalysis of ethylenediamine, lithium iron phosphate particles are reacted, and graphene oxide microsheets self-assemble and the precipitated lithium iron phosphate particles are tightly wrapped between the self-assembled graphene sheets. . Subsequently, the obtained composite material was washed and dried, and then heat-treated at 700° C. under the protection of argon for 5 hours to obtain a graphene/lithium iron phosphate/graphene composite positive electrode material.
上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料通过X射线衍射仪（TD-3200，丹东通达，Cu Kα）进行检测，所得的XRD测试结果与图1相似。图谱中所有的衍射峰都可以标定为橄榄石结构磷酸铁锂的衍射峰，没有其他物质的峰位出现，表明上述的石墨烯的含量并不影响磷酸铁锂的结构。进一步的分析表明，该石墨烯/磷酸铁锂/石墨烯复合正极材料中，磷酸铁锂的含量为78.3%，石墨烯的含量为21.7%。The graphene/lithium iron phosphate/graphene composite cathode material obtained above was detected by an X-ray diffractometer (TD-3200, Dandong Tongda, Cu Kα), and the obtained XRD test results were similar to those shown in Figure 1. All the diffraction peaks in the spectrum can be calibrated as the diffraction peaks of olivine structure lithium iron phosphate, and no peak positions of other substances appear, indicating that the above-mentioned graphene content does not affect the structure of lithium iron phosphate. Further analysis shows that in the graphene/lithium iron phosphate/graphene composite cathode material, the content of lithium iron phosphate is 78.3%, and the content of graphene is 21.7%.
上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料，使用扫描电镜（SEM，日本电子6700F）所得的SEM图与图2相似。所得的磷酸铁锂颗粒直径在100-200纳米之间，且被石墨烯较好的包裹，这种结构可以为材料提供导电网络从而提高材料的电导率，达到提高材料的电化学性能的目的。石墨烯包裹磷酸铁锂颗粒既提高其导电性，又起到相应的保护作用，可以提高材料的循环性能。The graphene/lithium iron phosphate/graphene composite positive electrode material obtained above is similar to FIG. 2 in the SEM image obtained by using a scanning electron microscope (SEM, JEOL 6700F). The obtained lithium iron phosphate particles have a diameter of 100-200 nanometers and are well wrapped by graphene. This structure can provide a conductive network for the material to improve the electrical conductivity of the material and achieve the purpose of improving the electrochemical performance of the material. Graphene wrapping lithium iron phosphate particles not only improves its conductivity, but also plays a corresponding protective role, which can improve the cycle performance of the material.
将上述所得的石墨烯/磷酸铁锂/石墨烯复合正极材料，使用半电池方法组装成纽扣式2016电池在1C的倍率下对该电池的充放电性能进行测试，放电容量为149.6 mAh/g，50次循环后其容量为146 mAh/g，容量保持率97.6%。由此表明，本发明所得的石墨烯/磷酸铁锂/石墨烯电池正极材料具有较高的质量比容量和良好的循环稳定性，将可以在锂离子电池领域应用。The graphene/lithium iron phosphate/graphene composite positive electrode material obtained above was assembled into a button-type 2016 battery using a half-cell method. The charge-discharge performance of the battery was tested at a rate of 1C, and the discharge capacity was 149.6 mAh/g. After 50 cycles, its capacity is 146 mAh/g, and the capacity retention rate is 97.6%. This shows that the graphene/lithium iron phosphate/graphene battery positive electrode material obtained in the present invention has higher mass specific capacity and good cycle stability, and will be applicable in the field of lithium ion batteries.
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| CN107464925A (en) * | 2017-08-02 | 2017-12-12 | 商丘职业技术学院 | A kind of lithium battery and power device |
| CN108470889A (en) * | 2018-03-12 | 2018-08-31 | 澳洋集团有限公司 | A kind of preparation method of LiFePO4-graphite composite positive pole |
| CN114735688A (en) * | 2019-05-31 | 2022-07-12 | 常州第六元素材料科技股份有限公司 | Graphene oxide slurry with interlayer bonded diamine organic compounds and preparation method thereof, graphene oxide film and preparation method thereof |
| CN117482969A (en) * | 2023-11-01 | 2024-02-02 | 安徽大学 | A "sandwich" structure carbon dioxide hydrogenation to light gasoline catalyst and its preparation method and application |
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| CN103682368A (en) * | 2012-09-20 | 2014-03-26 | 中国科学院金属研究所 | A kind of fast charging flexible lithium ion battery and preparation method of electrode thereof |
| CN105977465A (en) * | 2016-06-29 | 2016-09-28 | 上海应用技术学院 | Method for preparing graphene/lithium iron phosphate composite anode materials |
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| CN103682368A (en) * | 2012-09-20 | 2014-03-26 | 中国科学院金属研究所 | A kind of fast charging flexible lithium ion battery and preparation method of electrode thereof |
| CN105977465A (en) * | 2016-06-29 | 2016-09-28 | 上海应用技术学院 | Method for preparing graphene/lithium iron phosphate composite anode materials |
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| CN107464925A (en) * | 2017-08-02 | 2017-12-12 | 商丘职业技术学院 | A kind of lithium battery and power device |
| CN108470889A (en) * | 2018-03-12 | 2018-08-31 | 澳洋集团有限公司 | A kind of preparation method of LiFePO4-graphite composite positive pole |
| CN114735688A (en) * | 2019-05-31 | 2022-07-12 | 常州第六元素材料科技股份有限公司 | Graphene oxide slurry with interlayer bonded diamine organic compounds and preparation method thereof, graphene oxide film and preparation method thereof |
| CN117482969A (en) * | 2023-11-01 | 2024-02-02 | 安徽大学 | A "sandwich" structure carbon dioxide hydrogenation to light gasoline catalyst and its preparation method and application |
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