WO2018152755A1 - Secondary battery and preparation method therefor - Google Patents

Abstract

Provided is a secondary battery, comprising a positive electrode, an electrolytic solution, a negative electrode and a diaphragm, wherein the positive electrode comprises a positive electrode current collector, and a positive electrode active material layer arranged on the positive electrode current collector; the positive electrode active material layer comprises a positive electrode active material, and the positive electrode active material comprises a material into which potassium salt anions can be embedded; the electrolytic solution comprises potassium salt and a non-aqueous solvent; and the negative electrode comprises a metal foil, and the metal foil serves as a negative electrode current collector and a negative electrode active material at the same time. An electrolytic solution of the secondary battery takes potassium salt as an electrolyte, thereby solving the problem of limited lithium resource reserves in lithium secondary batteries commonly used at present, reducing the cost of the secondary battery and achieving environmental friendliness. In addition, since the metal foil serves as a negative electrode active material and a current collector at the same time, the weight and volume of the battery are reduced, thus improving the energy density of the battery, and saving on the production costs of the battery at the same time.

Description

一种二次电池及其制备方法Secondary battery and preparation method thereof 技术领域Technical field

本发明涉及二次电池技术领域，特别是涉及一种二次电池及其制备方法。The present invention relates to the field of secondary battery technology, and in particular to a secondary battery and a method of fabricating the same.

背景技术Background technique

二次电池也称为可充电电池，是一种可重复充放电、使用多次的电池。相比一次电池，二次电池具有使用成本低、对环境污染小的优点。目前主要的二次电池技术有铅酸电池、镍铬电池、镍氢电池、锂离子电池等，其中尤其以锂离子电池应用最为广泛。但是锂离子电池面临着锂资源储量有限、成本高的问题。作为潜在取代锂离子电池的储能技术，钾离子电池在近几年日益受到关注。A secondary battery, also called a rechargeable battery, is a battery that can be repeatedly charged and discharged and used multiple times. Compared with primary batteries, secondary batteries have the advantages of low cost of use and low environmental pollution. At present, the main secondary battery technologies include lead-acid batteries, nickel-chromium batteries, nickel-hydrogen batteries, and lithium-ion batteries, among which lithium-ion batteries are the most widely used. However, lithium-ion batteries face the problem of limited lithium resource reserves and high cost. As an energy storage technology that potentially replaces lithium-ion batteries, potassium-ion batteries have received increasing attention in recent years.

钾离子电池的工作原理与锂离子电池类似，但是电池中电荷的储存与释放是通过钾离子的迁移实现。钾离子电池的核心组成部件包含正极、负极和电解液，它通过发生在正极、负极与电解液界面上的离子传输与电子传输相分离的氧化还原反应来实现电能存储与释放。充电时，钾离子从正极活性材料中脱出，嵌入负极活性材料；放电时，钾离子从负极活性材料脱出而嵌入到正极活性材料中。常见的钾离子电池是以普鲁士蓝及其类似物、磷酸铁、氟硫酸铁等为正极活性材料，以碳材料为负极活性材料。但是目前基于钾离子电池开发出的正负极材料种类非常有限，且研究基本只限于对钾片的半电池，基于已开发材料的钾离子电池的电化学性能不是很理想，而且制备工艺也较为复杂。Potassium-ion batteries work similarly to lithium-ion batteries, but the storage and release of charge in the battery is achieved by the migration of potassium ions. The core component of the potassium ion battery comprises a positive electrode, a negative electrode and an electrolyte, which realizes energy storage and release by a redox reaction in which ion transport and electron transport phase separation occurs at the interface between the positive electrode, the negative electrode and the electrolyte. When charging, potassium ions are removed from the positive electrode active material and embedded in the negative electrode active material; when discharged, potassium ions are extracted from the negative electrode active material and embedded in the positive electrode active material. Common potassium ion batteries are Prussian blue and its analogues, iron phosphate, iron fluorosulfate and the like as positive electrode active materials, and carbon materials as negative electrode active materials. However, the types of positive and negative materials developed based on potassium ion batteries are very limited, and the research is basically limited to the half cells of potassium plates. The electrochemical performance of potassium ion batteries based on developed materials is not very satisfactory, and the preparation process is also relatively good. complex.

发明内容Summary of the invention

鉴于此，本发明第一方面提供了一种二次电池，该电池以石墨等可嵌入钾盐阴离子的材料作为正极活性材料，以金属箔片同时作为负极集流体和负极活性 材料，以钾盐作为电解质，旨在解决现有常用的锂二次电池存在的锂资源储量有限，成本高的问题，以及现有钾离子电池电化学性能不理想，工艺复杂的问题。In view of this, the first aspect of the present invention provides a secondary battery using a material such as graphite which can be embedded in a potassium salt anion as a positive electrode active material, and a metal foil as a negative electrode current collector and a negative electrode active simultaneously. The material, with potassium salt as the electrolyte, aims to solve the problem that the existing lithium secondary battery has limited lithium resource reserves, high cost, and the electrochemical performance of the existing potassium ion battery is not ideal, and the process is complicated.

具体地，第一方面，本发明提供了一种二次电池，包括：Specifically, in a first aspect, the present invention provides a secondary battery comprising:

正极，包括正极集流体和正极活性材料，所述正极活性材料包括可嵌入钾盐阴离子的材料；a positive electrode comprising a positive electrode current collector and a positive electrode active material, the positive electrode active material comprising a material capable of intercalating a potassium salt anion;

电解液，包括钾盐和非水溶剂；An electrolyte comprising a potassium salt and a non-aqueous solvent;

负极，包括金属箔片，所述金属箔片同时作为负极集流体和负极活性材料；a negative electrode comprising a metal foil, the metal foil simultaneously serving as a negative current collector and a negative active material;

以及隔膜，所述隔膜介于所述正极与所述负极之间。And a separator interposed between the positive electrode and the negative electrode.

其中，所述正极活性材料包括碳材料、硫化物、氮化物、氧化物、碳化物、以及上述各材料的复合物中的一种或多种。Wherein, the positive electrode active material includes one or more of a carbon material, a sulfide, a nitride, an oxide, a carbide, and a composite of the above materials.

所述碳材料包括石墨类碳材料、玻璃碳、碳碳复合材料、碳纤维、硬碳、多孔炭、炭黑、碳纳米管、石墨烯中的一种或多种。The carbon material includes one or more of a graphite-based carbon material, a glassy carbon, a carbon-carbon composite material, carbon fiber, hard carbon, porous carbon, carbon black, carbon nanotubes, and graphene.

所述石墨类碳材料包括天然石墨、膨胀石墨、人造石墨、中间相碳微球石墨、热解石墨、高取向石墨、三维石墨海绵中的一种或多种。The graphite-based carbon material includes one or more of natural graphite, expanded graphite, artificial graphite, mesocarbon microbead graphite, pyrolytic graphite, highly oriented graphite, and three-dimensional graphite sponge.

所述硫化物选自二硫化钼、二硫化钨、二硫化钒、二硫化钛、二硫化铁、硫化亚铁、硫化镍、硫化锌、硫化钴、硫化锰中的一种或多种；所述氮化物选自六方氮化硼、碳掺杂六方氮化硼中的一种或多种；所述氧化物选自三氧化钼、三氧化钨、五氧化二钒、二氧化钒、二氧化钛、氧化锌、氧化铜、氧化镍、氧化锰中的一种或多种；所述碳化物选自碳化钛、碳化钽、碳化钼、碳化硅中的一种或多种。The sulfide is selected from the group consisting of molybdenum disulfide, tungsten disulfide, vanadium disulfide, titanium disulfide, iron disulfide, ferrous sulfide, nickel sulfide, zinc sulfide, cobalt sulfide, manganese sulfide; The nitride is selected from one or more of hexagonal boron nitride and carbon doped hexagonal boron nitride; the oxide is selected from the group consisting of molybdenum trioxide, tungsten trioxide, vanadium pentoxide, vanadium dioxide, titanium dioxide, One or more of zinc oxide, copper oxide, nickel oxide, and manganese oxide; the carbide is selected from one or more of titanium carbide, tantalum carbide, molybdenum carbide, and silicon carbide.

所述金属箔片的材质包括锡、锌、铅、锑、镉、金、铋、锗中的任意一种，或含有至少一种上述金属元素的合金，或含有至少一种上述金属元素的复合材 料。The material of the metal foil includes any one of tin, zinc, lead, antimony, cadmium, gold, bismuth, antimony, or an alloy containing at least one of the above metal elements, or a composite containing at least one of the above metal elements. Material material.

所述正极集流体的材质包括铝、铜、铁、锡、锌、镍、钛、锰中的任意一种，或含有至少一种上述金属元素的合金，或含有至少一种上述金属元素的复合材料。The material of the positive electrode current collector includes any one of aluminum, copper, iron, tin, zinc, nickel, titanium, manganese, or an alloy containing at least one of the above metal elements, or a composite containing at least one of the above metal elements. material.

所述钾盐包括六氟磷酸钾、氯化钾、氟化钾、硫酸钾、碳酸钾、磷酸钾、硝酸钾、二氟草酸硼酸钾、焦磷酸钾、十二烷基苯磺酸钾、十二烷基硫酸钾、柠檬酸三钾、偏硼酸钾、硼酸钾、钼酸钾、钨酸钾、溴化钾、亚硝酸钾、碘酸钾、碘化钾、硅酸钾、木质素磺酸钾、草酸钾、铝酸钾、甲基磺酸钾、醋酸钾、重铬酸钾、六氟砷酸钾、四氟硼酸钾、高氯酸钾、三氟甲烷磺酰亚胺钾、三氟甲基磺酸钾中的一种或多种。所述电解液中，钾盐的浓度为0.1–10mol/L。The potassium salt comprises potassium hexafluorophosphate, potassium chloride, potassium fluoride, potassium sulfate, potassium carbonate, potassium phosphate, potassium nitrate, potassium difluorooxalate borate, potassium pyrophosphate, potassium dodecylbenzenesulfonate, ten Potassium dialkyl sulfate, tripotassium citrate, potassium metaborate, potassium borate, potassium molybdate, potassium tungstate, potassium bromide, potassium nitrite, potassium iodate, potassium iodide, potassium silicate, potassium lignosulfonate, Potassium oxalate, potassium aluminate, potassium methanesulfonate, potassium acetate, potassium dichromate, potassium hexafluoroarsenate, potassium tetrafluoroborate, potassium perchlorate, potassium trifluoromethanesulfonimide, trifluoromethanesulfonic acid One or more of potassium. In the electrolytic solution, the concentration of the potassium salt is 0.1 - 10 mol / L.

所述非水溶剂包括有机溶剂和离子液体，所述有机溶剂包括酯类、砜类、醚类、腈类有机溶剂中的一种或多种。The nonaqueous solvent includes an organic solvent and an ionic liquid, and the organic solvent includes one or more of an ester, a sulfone, an ether, and a nitrile organic solvent.

所述有机溶剂包括碳酸丙烯酯(PC)、碳酸乙烯酯(EC)、碳酸二乙酯(DEC)、碳酸二甲酯(DMC)、碳酸甲乙酯(EMC)、甲酸甲酯(MF)、乙酸甲酯(MA)、N,N-二甲基乙酰胺(DMA)、氟代碳酸乙烯酯(FEC)、丙酸甲酯(MP)、丙酸乙酯(EP)、乙酸乙酯(EA)、γ-丁内酯(GBL)、四氢呋喃(THF)、2-甲基四氢呋喃(2MeTHF)、1,3-二氧环戊烷(DOL)、4-甲基-1,3-二氧环戊烷(4MeDOL)、二甲氧甲烷(DMM)、1,2-二甲氧丙烷(DMP)、三乙二醇二甲醚(DG)、二甲基砜(MSM)、二甲醚(DME)、亚硫酸乙烯酯(ES)、亚硫酸丙烯脂(PS)、亚硫酸二甲脂(DMS)、亚硫酸二乙脂(DES)、冠醚(12-冠-4)中的一种或多种。The organic solvent includes propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), methyl formate (MF), Methyl acetate (MA), N,N-dimethylacetamide (DMA), fluoroethylene carbonate (FEC), methyl propionate (MP), ethyl propionate (EP), ethyl acetate (EA) ), γ-butyrolactone (GBL), tetrahydrofuran (THF), 2-methyltetrahydrofuran (2MeTHF), 1,3-dioxocyclopentane (DOL), 4-methyl-1,3-dioxane Pentane (4MeDOL), dimethoxymethane (DMM), 1,2-dimethoxypropane (DMP), triethylene glycol dimethyl ether (DG), dimethyl sulfone (MSM), dimethyl ether (DME) ), one of vinyl sulfite (ES), propylene sulfite (PS), dimethyl sulfite (DMS), diethyl sulfite (DES), crown ether (12-crown-4) or A variety.

所述离子液体包括1-乙基-3-甲基咪唑-六氟磷酸盐、1-乙基-3-甲基咪唑-四氟硼酸盐、1-乙基-3-甲基咪唑-双三氟甲基磺酰亚胺盐、1-丙基-3-甲基咪唑-六氟磷酸盐、1-丙基-3-甲基咪唑-四氟硼酸盐、1-丙基-3-甲基咪唑-双三氟甲基磺酰亚胺 盐、1-丁基-1-甲基咪唑-六氟磷酸盐、1-丁基-1-甲基咪唑-四氟硼酸盐、1-丁基-1-甲基咪唑-双三氟甲基磺酰亚胺盐、N-丁基-N-甲基吡咯烷-双三氟甲基磺酰亚胺盐、1-丁基-1-甲基吡咯烷-双三氟甲基磺酰亚胺盐、N-甲基-N-丙基吡咯烷-双三氟甲基磺酰亚胺盐、N-甲,丙基哌啶-双三氟甲基磺酰亚胺盐、N-甲,丁基哌啶-双三氟甲基磺酰亚胺盐中的一种或多种。The ionic liquid includes 1-ethyl-3-methylimidazolium-hexafluorophosphate, 1-ethyl-3-methylimidazole-tetrafluoroborate, 1-ethyl-3-methylimidazole-double Trifluoromethylsulfonimide salt, 1-propyl-3-methylimidazole-hexafluorophosphate, 1-propyl-3-methylimidazole-tetrafluoroborate, 1-propyl-3- Methylimidazole-bistrifluoromethylsulfonimide Salt, 1-butyl-1-methylimidazole-hexafluorophosphate, 1-butyl-1-methylimidazole-tetrafluoroborate, 1-butyl-1-methylimidazole-bistrifluoromethyl Base sulfonimide salt, N-butyl-N-methylpyrrolidine-bistrifluoromethylsulfonimide salt, 1-butyl-1-methylpyrrolidine-bistrifluoromethylsulfonyl Amine salt, N-methyl-N-propylpyrrolidine-bistrifluoromethylsulfonimide salt, N-methyl, propyl piperidine-bistrifluoromethylsulfonimide salt, N-methyl, One or more of butyl piperidine-bistrifluoromethylsulfonimide salts.

所述电解液中还包括添加剂，所述添加剂包括酯类、砜类、醚类、腈类和烯烃类有机添加剂中的一种或多种，所述添加剂在所述电解液中的质量分数为0.1-20％。具体地，所述添加剂包括氟代碳酸乙烯酯、碳酸亚乙烯酯、碳酸乙烯亚乙酯、1,3-丙磺酸内酯、1,4-丁磺酸内酯、硫酸乙烯酯、硫酸丙烯酯、硫酸亚乙酯、亚硫酸乙烯酯、亚硫酸丙烯酯、二甲基亚硫酸酯、二乙基亚硫酸酯、亚硫酸亚乙酯、氯代甲酸甲脂、二甲基亚砜、苯甲醚、乙酰胺、二氮杂苯、间二氮杂苯、冠醚12-冠-4、冠醚18-冠-6、4-氟苯甲醚、氟代链状醚、二氟代甲基碳酸乙烯酯、三氟代甲基碳酸乙烯酯、氯代碳酸乙烯酯、溴代碳酸乙烯酯、三氟乙基膦酸、溴代丁内酯、氟代乙酸基乙烷、磷酸酯、亚磷酸酯、磷腈、乙醇胺、碳化二甲胺、环丁基砜、1,3-二氧环戊烷、乙腈、长链烯烃、三氧化二铝、氧化镁、氧化钡、碳酸钠、碳酸钙、二氧化碳、二氧化硫、碳酸锂中的一种或多种。The electrolyte further includes an additive comprising one or more of an ester, a sulfone, an ether, a nitrile, and an olefin organic additive, and the mass fraction of the additive in the electrolyte is 0.1-20%. Specifically, the additive includes fluoroethylene carbonate, vinylene carbonate, ethylene carbonate, 1,3-propane sultone, 1,4-butane sultone, vinyl sulfate, propylene sulfate Ester, ethylene sulfate, vinyl sulfite, propylene sulfite, dimethyl sulfite, diethyl sulfite, ethylene sulfite, methyl chloroformate, dimethyl sulfoxide, benzene Methyl ether, acetamide, diazabenzene, m-diazabenzene, crown ether 12-crown-4, crown ether 18-crown-6, 4-fluoroanisole, fluorochain ether, difluoromethyl Ethylene carbonate, trifluoromethyl ethylene carbonate, vinyl chlorocarbonate, vinyl bromoacetate, trifluoroethylphosphonic acid, bromobutyrolactone, fluoroacetoxyethane, phosphate, sub Phosphate, phosphazene, ethanolamine, dimethylamine, cyclobutylsulfone, 1,3-dioxocyclopentane, acetonitrile, long-chain olefin, aluminum oxide, magnesium oxide, cerium oxide, sodium carbonate, calcium carbonate One or more of carbon dioxide, sulfur dioxide, and lithium carbonate.

所述隔膜为绝缘的多孔聚合物薄膜或无机多孔薄膜。The separator is an insulating porous polymer film or an inorganic porous film.

本发明第一方面提供的二次电池，以钾盐作为电解质，解决了现有锂二次电池存在的锂资源储量有限的问题，降低了电池成本且环境友好；此外，本发明提供的二次电池直接将金属箔片同时作为负极活性材料和集流体，有效地降低了电池的重量和体积，提高了电池的能量密度，且该二次电池具有良好的充放电循环性能。The secondary battery provided by the first aspect of the present invention solves the problem that the existing lithium secondary battery has limited lithium resource reserves by using the potassium salt as the electrolyte, reduces the battery cost and is environmentally friendly; The battery directly uses the metal foil as the negative active material and the current collector, effectively reducing the weight and volume of the battery, improving the energy density of the battery, and the secondary battery has good charge and discharge cycle performance.

第二方面，本发明提供了一种二次电池的制备方法，包括以下步骤： In a second aspect, the present invention provides a method of preparing a secondary battery, comprising the steps of:

提供正极集流体，在所述正极集流体上制备正极活性材料层，干燥、压制后裁切成所需尺寸，得到正极；所述正极活性材料层包括正极活性材料，所述正极活性材料包括可嵌入钾盐阴离子的材料；Providing a positive electrode current collector, preparing a positive electrode active material layer on the positive electrode current collector, drying, pressing, and cutting into a desired size to obtain a positive electrode; the positive electrode active material layer including a positive electrode active material, the positive electrode active material including a material embedded with a potassium salt anion;

将金属箔片裁切成所需的尺寸，经表面清洗、干燥后，得到负极；所述金属箔片同时作为负极集流体和负极活性材料；Cutting the metal foil into a desired size, after surface cleaning and drying, obtaining a negative electrode; the metal foil simultaneously serving as a negative current collector and a negative active material;

提供电解液和隔膜，所述电解液包括钾盐和非水溶剂，在惰性气体或无水环境下，将所述负极、隔膜、正极依次紧密堆叠，加入所述电解液使所述隔膜完全浸润，然后将上述堆叠部分封装入电池壳体，得到二次电池。Providing an electrolyte and a separator, the electrolyte comprising a potassium salt and a non-aqueous solvent, wherein the anode, the separator, and the cathode are sequentially closely packed in an inert gas or an anhydrous environment, and the electrolyte is added to completely infiltrate the separator Then, the above stacked portion is packaged into a battery case to obtain a secondary battery.

本发明第二方面提供的二次电池的制备方法，工艺简单，适于规模化生产。The method for preparing a secondary battery provided by the second aspect of the invention has a simple process and is suitable for large-scale production.

本发明的优点将会在下面的说明书中部分阐明，一部分根据说明书是显而易见的，或者可以通过本发明实施例的实施而获知。The advantages of the invention will be set forth in part in the description which follows.

附图说明DRAWINGS

图1是本发明实施例提供的二次电池的结构示意图。FIG. 1 is a schematic structural view of a secondary battery according to an embodiment of the present invention.

具体实施方式detailed description

下面结合附图和具体实施方式对本发明作进一步详细说明。以下所述是本发明实施例的优选实施方式，应当指出，对于本技术领域的普通技术人员来说，在不脱离本发明实施例原理的前提下，还可以做出若干改进和润饰，这些改进和润饰也视为本发明实施例的保护范围。The present invention will be further described in detail below in conjunction with the drawings and specific embodiments. The following are the preferred embodiments of the embodiments of the present invention, and it should be noted that those skilled in the art can make some improvements and refinements without departing from the principles of the embodiments of the present invention. And retouching is also considered to be the scope of protection of the embodiments of the present invention.

参照图1，本发明实施例提供了一种二次电池，包括正极集流体10、正极活性材料层20、电解液30、隔膜40、负极50；其中，正极集流体10与设置在正极集流体10上的正极活性材料层20共同构成电池正极，所述正极活性材料 层20包括可嵌入钾盐阴离子的正极活性材料；负极50包括金属箔片，该金属箔片同时作为负极集流体和负极活性材料；电解液30包括钾盐和非水溶剂；隔膜40介于正极与负极50之间。Referring to FIG. 1, an embodiment of the present invention provides a secondary battery including a cathode current collector 10, a cathode active material layer 20, an electrolyte 30, a separator 40, and a cathode 50. The cathode current collector 10 and the cathode current collector are disposed. The positive electrode active material layer 20 on 10 collectively constitutes a battery positive electrode, and the positive electrode active material The layer 20 includes a positive electrode active material capable of intercalating a potassium salt anion; the negative electrode 50 includes a metal foil which serves as both a negative electrode current collector and a negative electrode active material; the electrolyte 30 includes a potassium salt and a nonaqueous solvent; and the separator 40 is interposed between the positive electrode and the positive electrode active material; Between the anode 50 and the anode 50.

本发明实施例提供的上述二次电池的工作原理为：在充电过程中，电解液中的阴离子迁移至正极并嵌入正极活性材料中，钾离子迁移至负极并与负极形成钾-金属合金；放电过程中阴离子从正极活性材料中脱出回到电解液中，钾离子从负极去合金化回到电解液中，从而实现整个充放电过程。在上述充放电过程中，电解液全部采用钾盐作为电解质，解决了锂资源储量有限的问题，降低了二次电池成本，减轻了电池对环境的影响；此外，由于负极金属箔片同时作为负极活性材料和集流体，使得电池重量和体积降低，电池容量提高，进而提高了电池能量密度，并且节约了电池生产制造成本。The working principle of the above secondary battery provided by the embodiment of the present invention is: during the charging process, the anion in the electrolyte migrates to the positive electrode and is embedded in the positive active material, the potassium ion migrates to the negative electrode and forms a potassium-metal alloy with the negative electrode; During the process, the anion is removed from the positive electrode active material and returned to the electrolyte, and the potassium ions are de-alloyed from the negative electrode to the electrolyte to realize the entire charge and discharge process. In the above charging and discharging process, the electrolyte uses potassium salt as the electrolyte, which solves the problem of limited lithium resource reserves, reduces the cost of the secondary battery, and reduces the environmental impact of the battery; in addition, since the negative metal foil serves as the negative electrode at the same time The active material and the current collector reduce the weight and volume of the battery, increase the battery capacity, thereby increasing the energy density of the battery, and saving the manufacturing cost of the battery.

本发明实施方式中，所述正极活性材料包括碳材料、硫化物、氮化物、氧化物、碳化物、以及上述各材料的复合物中的一种或多种。其中，所述碳材料包括石墨类碳材料、玻璃碳、碳碳复合材料、碳纤维、硬碳、多孔炭、炭黑、碳纳米管、石墨烯中的一种或多种。具体地，所述石墨类碳材料包括天然石墨、膨胀石墨、人造石墨、中间相碳微球石墨、热解石墨、高取向石墨、三维石墨海绵中的一种或多种。In an embodiment of the invention, the cathode active material includes one or more of a carbon material, a sulfide, a nitride, an oxide, a carbide, and a composite of the above materials. Wherein, the carbon material comprises one or more of a graphite-based carbon material, a glassy carbon, a carbon-carbon composite material, carbon fiber, hard carbon, porous carbon, carbon black, carbon nanotubes, and graphene. Specifically, the graphite-based carbon material includes one or more of natural graphite, expanded graphite, artificial graphite, mesocarbon microbead graphite, pyrolytic graphite, highly oriented graphite, and three-dimensional graphite sponge.

本发明实施方式中，所述硫化物选自二硫化钼、二硫化钨、二硫化钒、二硫化钛、二硫化铁、硫化亚铁、硫化镍、硫化锌、硫化钴、硫化锰中的一种或多种；所述氮化物选自六方氮化硼、碳掺杂六方氮化硼中的一种或多种；所述氧化物选自三氧化钼、三氧化钨、五氧化二钒、二氧化钒、二氧化钛、氧化锌、氧化铜、氧化镍、氧化锰中的一种或多种；所述碳化物选自碳化钛、碳化钽、碳化钼、碳化硅中的一种或多种。 In an embodiment of the invention, the sulfide is selected from the group consisting of molybdenum disulfide, tungsten disulfide, vanadium disulfide, titanium disulfide, iron disulfide, ferrous sulfide, nickel sulfide, zinc sulfide, cobalt sulfide, and manganese sulfide. Or a plurality of; the nitride is selected from one or more of hexagonal boron nitride and carbon-doped hexagonal boron nitride; the oxide is selected from the group consisting of molybdenum trioxide, tungsten trioxide, vanadium pentoxide, One or more of vanadium dioxide, titanium dioxide, zinc oxide, copper oxide, nickel oxide, manganese oxide; the carbide is selected from one or more of titanium carbide, tantalum carbide, molybdenum carbide, silicon carbide.

本发明实施方式中，所述正极活性材料和负极活性材料具有层状晶体结构。In the embodiment of the invention, the cathode active material and the anode active material have a layered crystal structure.

本发明实施方式中，所述金属箔片的材质包括锡、锌、铅、锑、镉、金、铋、锗中的任意一种或含有至少一种上述金属元素的合金，或含有至少一种上述金属元素的复合材料。In the embodiment of the present invention, the material of the metal foil includes any one of tin, zinc, lead, antimony, cadmium, gold, antimony, bismuth or an alloy containing at least one of the above metal elements, or at least one kind a composite material of the above metal elements.

本发明实施方式中，所述正极集流体包括铝、铜、铁、锡、锌、镍、钛、锰中的任意一种或含有至少一种上述金属元素的合金，或含有至少一种上述金属元素的复合材料。In an embodiment of the invention, the cathode current collector comprises any one of aluminum, copper, iron, tin, zinc, nickel, titanium, manganese or an alloy containing at least one of the above metal elements, or contains at least one of the above metals The composite of the elements.

本发明实施方式中，作为电解质的钾盐可以是六氟磷酸钾、氯化钾、氟化钾、硫酸钾、碳酸钾、磷酸钾、硝酸钾、二氟草酸硼酸钾、焦磷酸钾、十二烷基苯磺酸钾、十二烷基硫酸钾、柠檬酸三钾、偏硼酸钾、硼酸钾、钼酸钾、钨酸钾、溴化钾、亚硝酸钾、碘酸钾、碘化钾、硅酸钾、木质素磺酸钾、草酸钾、铝酸钾、甲基磺酸钾、醋酸钾、重铬酸钾、六氟砷酸钾、四氟硼酸钾、高氯酸钾、三氟甲烷磺酰亚胺钾、三氟甲基磺酸钾中的一种或多种。所述电解液中，钾盐的浓度可以为0.1-10mol/L。进一步地，钾盐的浓度可以为0.1–2mol/L。In the embodiment of the present invention, the potassium salt as the electrolyte may be potassium hexafluorophosphate, potassium chloride, potassium fluoride, potassium sulfate, potassium carbonate, potassium phosphate, potassium nitrate, potassium difluorooxalate borate, potassium pyrophosphate, and twelve. Potassium alkylbenzenesulfonate, potassium lauryl sulfate, tripotassium citrate, potassium metaborate, potassium borate, potassium molybdate, potassium tungstate, potassium bromide, potassium nitrite, potassium iodate, potassium iodide, silicic acid Potassium, potassium lignosulfonate, potassium oxalate, potassium aluminate, potassium methanesulfonate, potassium acetate, potassium dichromate, potassium hexafluoroarsenate, potassium tetrafluoroborate, potassium perchlorate, trifluoromethanesulfonimide One or more of potassium and potassium trifluoromethanesulfonate. In the electrolytic solution, the concentration of the potassium salt may be from 0.1 to 10 mol/L. Further, the concentration of the potassium salt may be 0.1 - 2 mol / L.

本发明实施方式中，电解液中的非水溶剂没有特别限制，只要可以使电解质离解成钾离子和阴离子，且钾离子和阴离子可以自由迁移即可。具体地，所述非水溶剂包括有机溶剂和离子液体，所述有机溶剂可以是酯类、砜类、醚类、腈类有机溶剂中的一种或多种。更具体地，所述有机溶剂可以是碳酸丙烯酯(PC)、碳酸乙烯酯(EC)、碳酸二乙酯(DEC)、碳酸二甲酯(DMC)、碳酸甲乙酯(EMC)、甲酸甲酯(MF)、乙酸甲酯(MA)、N,N-二甲基乙酰胺(DMA)、氟代碳酸乙烯酯(FEC)、丙酸甲酯(MP)、丙酸乙酯(EP)、乙酸乙酯(EA)、γ-丁内酯(GBL)、四氢呋喃(THF)、2-甲基四氢呋喃(2MeTHF)、1,3-二氧环戊烷(DOL)、4-甲基-1,3-二氧环戊烷(4MeDOL)、二甲氧甲烷(DMM)、1,2-二甲氧丙烷(DMP)、 三乙二醇二甲醚(DG)、二甲基砜(MSM)、二甲醚(DME)、亚硫酸乙烯酯(ES)、亚硫酸丙烯脂(PS)、亚硫酸二甲脂(DMS)、亚硫酸二乙脂(DES)、冠醚(12-冠-4)中的一种或多种。所述离子液体包括1-乙基-3-甲基咪唑-六氟磷酸盐、1-乙基-3-甲基咪唑-四氟硼酸盐、1-乙基-3-甲基咪唑-双三氟甲基磺酰亚胺盐、1-丙基-3-甲基咪唑-六氟磷酸盐、1-丙基-3-甲基咪唑-四氟硼酸盐、1-丙基-3-甲基咪唑-双三氟甲基磺酰亚胺盐、1-丁基-1-甲基咪唑-六氟磷酸盐、1-丁基-1-甲基咪唑-四氟硼酸盐、1-丁基-1-甲基咪唑-双三氟甲基磺酰亚胺盐、N-丁基-N-甲基吡咯烷-双三氟甲基磺酰亚胺盐、1-丁基-1-甲基吡咯烷-双三氟甲基磺酰亚胺盐、N-甲基-N-丙基吡咯烷-双三氟甲基磺酰亚胺盐、N-甲,丙基哌啶-双三氟甲基磺酰亚胺盐、N-甲,丁基哌啶-双三氟甲基磺酰亚胺盐中的一种或多种。In the embodiment of the present invention, the nonaqueous solvent in the electrolytic solution is not particularly limited as long as the electrolyte can be dissociated into potassium ions and anions, and the potassium ions and anions can be freely migrated. Specifically, the nonaqueous solvent includes an organic solvent and an ionic liquid, and the organic solvent may be one or more of an ester, a sulfone, an ether, and a nitrile organic solvent. More specifically, the organic solvent may be propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), formic acid Ester (MF), methyl acetate (MA), N,N-dimethylacetamide (DMA), fluoroethylene carbonate (FEC), methyl propionate (MP), ethyl propionate (EP), Ethyl acetate (EA), γ-butyrolactone (GBL), tetrahydrofuran (THF), 2-methyltetrahydrofuran (2MeTHF), 1,3-dioxocyclopentane (DOL), 4-methyl-1, 3-dioxolane (4MeDOL), dimethoxymethane (DMM), 1,2-dimethoxypropane (DMP), Triethylene glycol dimethyl ether (DG), dimethyl sulfone (MSM), dimethyl ether (DME), vinyl sulfite (ES), propylene sulfite (PS), dimethyl sulfite (DMS) One or more of diethyl sulfite (DES) and crown ether (12-crown-4). The ionic liquid includes 1-ethyl-3-methylimidazolium-hexafluorophosphate, 1-ethyl-3-methylimidazole-tetrafluoroborate, 1-ethyl-3-methylimidazole-double Trifluoromethylsulfonimide salt, 1-propyl-3-methylimidazole-hexafluorophosphate, 1-propyl-3-methylimidazole-tetrafluoroborate, 1-propyl-3- Methylimidazole-bistrifluoromethylsulfonimide salt, 1-butyl-1-methylimidazole-hexafluorophosphate, 1-butyl-1-methylimidazole-tetrafluoroborate, 1- Butyl-1-methylimidazole-bistrifluoromethylsulfonimide salt, N-butyl-N-methylpyrrolidine-bistrifluoromethylsulfonimide salt, 1-butyl-1- Methylpyrrolidine-bistrifluoromethylsulfonimide salt, N-methyl-N-propylpyrrolidine-bistrifluoromethylsulfonimide salt, N-methyl, propyl piperidine-double One or more of fluoromethylsulfonylimide salt, N-methyl, butyl piperidine-bistrifluoromethylsulfonimide salt.

本发明实施方式中，为了防止负极在充放电时因体积变化所造成的破坏，保持负极结构稳定，提高负极的使用寿命和性能，以提高二次电池的循环性能，所述电解液中还进一步包括添加剂，所述添加剂可以是酯类、砜类、醚类、腈类和烯烃类有机添加剂中的一种或多种。具体地，所述添加剂包括氟代碳酸乙烯酯、碳酸亚乙烯酯、碳酸乙烯亚乙酯、1,3-丙磺酸内酯、1,4-丁磺酸内酯、硫酸乙烯酯、硫酸丙烯酯、硫酸亚乙酯、亚硫酸乙烯酯、亚硫酸丙烯酯、二甲基亚硫酸酯、二乙基亚硫酸酯、亚硫酸亚乙酯、氯代甲酸甲脂、二甲基亚砜、苯甲醚、乙酰胺、二氮杂苯、间二氮杂苯、冠醚12-冠-4、冠醚18-冠-6、4-氟苯甲醚、氟代链状醚、二氟代甲基碳酸乙烯酯、三氟代甲基碳酸乙烯酯、氯代碳酸乙烯酯、溴代碳酸乙烯酯、三氟乙基膦酸、溴代丁内酯、氟代乙酸基乙烷、磷酸酯、亚磷酸酯、磷腈、乙醇胺、碳化二甲胺、环丁基砜、1,3-二氧环戊烷、乙腈、长链烯烃、三氧化二铝、氧化镁、氧化钡、碳酸钠、碳酸钙、二氧化碳、二氧化硫、碳酸锂中的一种或多种。在电解液中增加的添加剂在负极集流体(金 属箔片)表面可以形成稳定的固体电解质膜，使得金属箔片作为负极活性材料反应时不被破坏，提高电池的使用寿命。In the embodiment of the present invention, in order to prevent damage caused by volume change of the negative electrode during charge and discharge, the structure of the negative electrode is kept stable, and the service life and performance of the negative electrode are improved to improve the cycle performance of the secondary battery, and the electrolyte further An additive is included, which may be one or more of an ester, a sulfone, an ether, a nitrile, and an olefinic organic additive. Specifically, the additive includes fluoroethylene carbonate, vinylene carbonate, ethylene carbonate, 1,3-propane sultone, 1,4-butane sultone, vinyl sulfate, propylene sulfate Ester, ethylene sulfate, vinyl sulfite, propylene sulfite, dimethyl sulfite, diethyl sulfite, ethylene sulfite, methyl chloroformate, dimethyl sulfoxide, benzene Methyl ether, acetamide, diazabenzene, m-diazabenzene, crown ether 12-crown-4, crown ether 18-crown-6, 4-fluoroanisole, fluorochain ether, difluoromethyl Ethylene carbonate, trifluoromethyl ethylene carbonate, vinyl chlorocarbonate, vinyl bromoacetate, trifluoroethylphosphonic acid, bromobutyrolactone, fluoroacetoxyethane, phosphate, sub Phosphate, phosphazene, ethanolamine, dimethylamine, cyclobutylsulfone, 1,3-dioxocyclopentane, acetonitrile, long-chain olefin, aluminum oxide, magnesium oxide, cerium oxide, sodium carbonate, calcium carbonate One or more of carbon dioxide, sulfur dioxide, and lithium carbonate. Additives added to the electrolyte in the anode current collector (gold The surface of the foil can form a stable solid electrolyte membrane, so that the metal foil is not destroyed when reacted as the anode active material, thereby improving the service life of the battery.

本发明实施方式中，所述添加剂在所述电解液中的质量分数为0.1-20％，进一步地可为2-5％。In an embodiment of the invention, the additive has a mass fraction in the electrolyte of 0.1-20%, and further may be 2-5%.

本发明实施方式中，隔膜可以是绝缘的多孔聚合物薄膜或无机多孔薄膜，具体可以选用多孔聚丙烯薄膜、多孔聚乙烯薄膜、多孔复合聚合物薄膜、玻璃纤维纸、多孔陶瓷隔膜中的一种或多种。In the embodiment of the present invention, the separator may be an insulating porous polymer film or an inorganic porous film, and specifically, one of a porous polypropylene film, a porous polyethylene film, a porous composite polymer film, a glass fiber paper, and a porous ceramic separator may be selected. Or a variety.

本发明实施方式中，正极活性材料层还包括导电剂以及粘结剂，其中正极活性材料的质量含量为60-90％，导电剂的质量含量为5-30％，粘结剂的质量含量为5-10％。进一步地，正极活性材料的质量含量为70-85％。本发明实施例对导电剂和粘结剂没有特别的限制，采用本领域常用的即可。导电剂可以为导电炭黑、导电碳球、导电石墨、碳纳米管、导电碳纤维、石墨烯、还原氧化石墨烯中的一种或多种。粘结剂可以为聚偏氟乙烯、聚四氟乙烯、聚乙烯醇、羧甲基纤维素、SBR橡胶、聚烯烃类中的一种或多种。In the embodiment of the present invention, the positive electrode active material layer further includes a conductive agent and a binder, wherein the positive electrode active material has a mass content of 60-90%, the conductive agent has a mass content of 5-30%, and the binder has a mass content of 5-10%. Further, the positive electrode active material has a mass content of 70-85%. The conductive agent and the binder are not particularly limited in the embodiment of the present invention, and it is generally used in the art. The conductive agent may be one or more of conductive carbon black, conductive carbon spheres, conductive graphite, carbon nanotubes, conductive carbon fibers, graphene, and reduced graphene oxide. The binder may be one or more of polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl alcohol, carboxymethyl cellulose, SBR rubber, and polyolefin.

相应地，本发明实施例还提供了一种上述二次电池的制备方法，包括以下步骤：Correspondingly, an embodiment of the present invention further provides a method for preparing the above secondary battery, comprising the following steps:

(1)制备正极：提供表面洁净的正极集流体，按一定比例称取正极活性材料、导电剂以及粘结剂，加入适当溶剂充分混合形成均匀浆料；然后将所述浆料均匀涂覆于正极集流体表面，形成正极活性材料层，待完全干燥后压制并裁切，得到所需尺寸的电池正极；(1) Preparation of positive electrode: providing a positive electrode current collector with a clean surface, weighing the positive electrode active material, the conductive agent and the binder in a certain ratio, adding a suitable solvent and thoroughly mixing to form a uniform slurry; then uniformly coating the slurry on the slurry Forming a positive electrode current collector surface, forming a positive electrode active material layer, pressing and cutting after being completely dried to obtain a battery positive electrode of a desired size;

(2)制备负极：将金属箔片裁切成所需的尺寸，经表面清洗、干燥后，得到负极；(2) preparing a negative electrode: the metal foil is cut into a desired size, and after surface cleaning and drying, a negative electrode is obtained;

(3)配制电解液：称取一定量钾盐电解质加入到非水溶剂中，充分搅拌溶 解，得到所需电解液。(3) Prepare the electrolyte: Weigh a certain amount of potassium salt electrolyte into the non-aqueous solvent, and fully dissolve Solution to obtain the desired electrolyte.

(4)制备隔膜：将多孔聚合物薄膜或无机多孔薄膜裁切成所需尺寸，清洗干净后，得到所需隔膜。(4) Preparation of a separator: A porous polymer film or an inorganic porous film is cut into a desired size, and after cleaning, a desired separator is obtained.

(5)电池组装：在惰性气体或无水环境下，将上述制得的电池负极、隔膜、正极依次紧密堆叠，加入所述电解液使所述隔膜完全浸润，然后将上述堆叠部分封装入电池壳体，完成组装，得到二次电池。(5) Battery assembly: the battery negative electrode, the separator, and the positive electrode prepared in the above-mentioned manner are closely stacked in an inert gas or anhydrous environment, and the electrolyte is added to completely infiltrate the separator, and then the stacked portion is packaged into a battery. The housing is assembled and a secondary battery is obtained.

需要说明的是尽管上述步骤(1)-(4)是以特定顺序描述了本发明二次电池制备方法的操作，但是，并非必须按照该特定顺序来执行这些操作。步骤(1)-(4)的操作可以同时或者任意先后执行。It is to be noted that although the above steps (1) to (4) describe the operation of the secondary battery preparing method of the present invention in a specific order, it is not necessary to perform these operations in this specific order. The operations of steps (1)-(4) can be performed simultaneously or in any order.

本发明实施例上述制备方法中应用到的原材料如前述实施例中所描述，此处不再赘述。The raw materials applied in the above preparation method of the present invention are as described in the foregoing embodiments, and are not described herein again.

下面列举具体的实施例进一步说明上述二次电池的制备方法。The preparation method of the above secondary battery will be further described below by way of specific examples.

实施例1Example 1

一种二次电池的制备方法，包括以下步骤：A method for preparing a secondary battery, comprising the steps of:

(1)制备电池负极：取厚度为0.02mm的锡箔，裁切成直径为12mm的圆片，用乙醇清洗锡箔表面，晾干作为负极备用；(1) Preparation of battery negative electrode: taking a tin foil with a thickness of 0.02 mm, cutting into a disk having a diameter of 12 mm, cleaning the surface of the tin foil with ethanol, and drying it as a negative electrode for use;

(2)制备隔膜：将玻璃纤维薄膜裁切成直径16mm的圆片后作为隔膜备用；(2) Preparing the separator: cutting the glass fiber membrane into a 16 mm diameter disc and using it as a separator;

(3)配制电解液：称取3g六氟磷酸钾(KPF₆)加入到5mL碳酸乙烯酯、碳酸二甲酯和碳酸甲乙酯(三者体积比为4:3:2)的混合溶剂中，搅拌至六氟磷酸钾完全溶解，然后加入质量分数为5％的氟代碳酸乙烯酯作为添加剂，充分搅拌均匀后得到电解液备用；(3) Preparing the electrolyte: Weigh 3g of potassium hexafluorophosphate (KPF ₆ ) and add it to a mixed solvent of 5mL of ethylene carbonate, dimethyl carbonate and ethyl methyl carbonate (the volume ratio of the three is 4:3:2). Stir until the potassium hexafluorophosphate is completely dissolved, and then add 5% of fluoroethylene carbonate as an additive, and stir well to obtain an electrolyte for use;

(4)制备电池正极：将0.8g膨胀石墨、0.1g碳黑、0.1g聚偏氟乙烯加入到5mL氮甲基吡咯烷酮溶液中，充分混合获得均匀浆料；然后将浆料均匀涂覆于 铝箔集流体表面并真空干燥。将干燥所得电极片裁切成直径为10mm的圆片，压实后作为正极备用；(4) Preparation of battery positive electrode: 0.8 g of expanded graphite, 0.1 g of carbon black, 0.1 g of polyvinylidene fluoride was added to 5 mL of nitromethylpyrrolidone solution, and thoroughly mixed to obtain a uniform slurry; then the slurry was uniformly coated. The aluminum foil collector surface is dried under vacuum. The dried electrode sheet is cut into a disk having a diameter of 10 mm, and compacted as a positive electrode for use;

(5)电池组装：在惰性气体保护的手套箱中，将上述制备好的负极、隔膜、正极依次紧密堆叠，滴加电解液使隔膜完全浸润，然后将上述堆叠部分封装入扣式电池壳体，完成电池组装，得到二次电池。(5) Battery assembly: In the inert gas-protected glove box, the prepared negative electrode, separator, and positive electrode are sequentially closely stacked, and the electrolyte is dripped to completely infiltrate the separator, and then the stacked portion is packaged into the button battery case. , complete the battery assembly and get the secondary battery.

本发明实施例1的二次电池的工作机理为：负极：

正极：

The working mechanism of the secondary battery of Embodiment 1 of the present invention is: negative electrode:

positive electrode:

对比例1Comparative example 1

以铝箔作为正极集流体，天然石墨作为正极活性材料，铝箔作为负极(铝箔同时作为负极活性材料和集流体)，LiPF₆为电解质，碳酸甲乙酯为电解液溶剂，且电解液中加入2％碳酸亚乙烯酯的添加剂，参照实施例1的方式组装成铝-石墨双离子电池。该电池的工作机理为：负极：

正极：

Aluminum foil is used as positive electrode current collector, natural graphite is used as positive electrode active material, aluminum foil is used as negative electrode (aluminum foil is used as negative electrode active material and current collector), LiPF ₆ is electrolyte, ethyl methyl carbonate is electrolyte solvent, and 2% is added to electrolyte. An additive of vinylene carbonate was assembled into an aluminum-graphite dual ion battery in the same manner as in Example 1. The working mechanism of the battery is: negative electrode:

positive electrode:

对比例2Comparative example 2

以铝箔作为正极集流体，普鲁士蓝作为正极活性材料，以钾箔作为对电极，KBF₄为电解质，参照实施例1的方式组装成钾二次电池半电池。该电池的工作机理为：负极：

正极：

Aluminum foil was used as a positive electrode current collector, Prussian blue was used as a positive electrode active material, potassium foil was used as a counter electrode, and KBF ₄ was an electrolyte, and a potassium secondary battery half-cell was assembled in the same manner as in Example 1. The working mechanism of the battery is: negative electrode:

positive electrode:

对比例3Comparative example 3

以铝箔作为正极集流体，钴酸锂作为正极活性材料，铜箔作为负极集流体，石墨作为负极活性材料，LiPF₆为电解质，参照实施例1的方式组装成传统锂离子电池。该电池的工作机理为：负极：

正极：

Aluminum foil was used as a positive electrode current collector, lithium cobaltate was used as a positive electrode active material, copper foil was used as a negative electrode current collector, graphite was used as a negative electrode active material, and LiPF ₆ was an electrolyte, and assembled into a conventional lithium ion battery in the same manner as in Example 1. The working mechanism of the battery is: negative electrode:

positive electrode:

将本发明上述实施例1所得二次电池与对比例1-3中的电池进行恒电流充放电测试，电流密度为100mA/g，电压范围为3-5V(本发明后续实施例均采用同样的测试方法获得电化学性能结果)。测试结果及其他各项参数如表1所示。The secondary battery obtained in the above Example 1 of the present invention and the battery in Comparative Example 1-3 were subjected to a constant current charge and discharge test, and the current density was 100 mA/g, and the voltage range was 3-5 V (the same applies to the subsequent embodiments of the present invention). The test method obtained electrochemical performance results). The test results and other parameters are shown in Table 1.

表1Table 1

从表1可知，本发明实施例1的以钾盐为电解质、以石墨为正极活性材料，以锡箔同时作为负极活性材料和集流体的双离子二次电池，工作电压比对比例1-3的电池高，且负极不含活性石墨，原料成本和工艺成本低，且环境友好，循环稳定性优异。It can be seen from Table 1 that the working electrode has the potassium salt as the electrolyte, the graphite as the positive electrode active material, and the tin foil as the negative electrode active material and the current collector of the double ion secondary battery, and the working voltage is proportional to the ratio of 1-3. The battery is high, and the negative electrode does not contain active graphite, the raw material cost and the process cost are low, and the environment is friendly, and the cycle stability is excellent.

实施例2-10Example 2-10

实施例2-10与实施例1的区别仅在于，负极的选材不同，具体如表2所示，将实施例2-12所得的二次电池进行恒电流充放电测试，其结果如表2所示： The difference between the embodiment 2-10 and the embodiment 1 is that the selection of the negative electrode is different. Specifically, as shown in Table 2, the secondary battery obtained in the embodiment 2-12 is subjected to a constant current charge and discharge test, and the results are shown in Table 2. Show:

表2Table 2

从表2可知，负极选用锡箔时，电池比容量更高，循环性能更好，能量密度最高。It can be seen from Table 2 that when the negative electrode is made of tin foil, the specific capacity of the battery is higher, the cycle performance is better, and the energy density is the highest.

实施例11-48Example 11-48

实施例11-48与实施例1的区别仅在于，正极活性材料不同，具体如表3所示，将实施例11-48所得的二次电池进行恒电流充放电测试，其测试结果如表3所示：The difference between the embodiment 11-48 and the embodiment 1 is that the positive electrode active material is different, and as shown in Table 3, the secondary battery obtained in the embodiment 11-48 is subjected to a constant current charge and discharge test, and the test results are shown in Table 3. Shown as follows:

表3table 3

从表3中可以看出，正极活性材料选用石墨类碳材料时，电池比容量更高，能量密度更高，循环性能也更佳。It can be seen from Table 3 that when the cathode active material is selected from a graphite-based carbon material, the specific capacity of the battery is higher, the energy density is higher, and the cycle performance is also better.

实施例49-76Example 49-76

实施例49-76与实施例1的区别仅在于，电解质盐不同，具体如表4所示，将上述实施例所得的二次电池进行恒电流充放电测试，其测试结果如表4所示： The difference between the embodiment 49-76 and the embodiment 1 is only that the electrolyte salt is different. Specifically, as shown in Table 4, the secondary battery obtained in the above embodiment is subjected to a constant current charge and discharge test, and the test results are shown in Table 4:

表4Table 4

从表4中可以看出，电解质选用KPF₆、KBF₄、KClO₄、六氟砷酸钾、三氟甲烷磺酰亚胺钾、三氟甲基磺酸钾等时，电池比容量更高，能量密度更高，循环稳定性更好。It can be seen from Table 4 that when the electrolyte is selected from KPF ₆ , KBF ₄ , KClO ₄ , potassium hexafluoroarsenate, potassium trifluoromethanesulfonimide, potassium trifluoromethanesulfonate, etc., the specific capacity of the battery is higher. Higher energy density and better cycle stability.

实施例77-78 Example 77-78

实施例77-78与实施例1的区别仅在于，电解质浓度不同，具体如表5所示，将上述实施例所得的二次电池进行恒电流充放电测试，其测试结果如表5所示：The results of Examples 77-78 differ from those of Example 1 only in that the electrolyte concentration is different. Specifically, as shown in Table 5, the secondary battery obtained in the above examples was subjected to a constant current charge and discharge test, and the test results are shown in Table 5:

表5table 5

从表5中可以看出，电解质浓度为1mol/L时，电池比容量高，能量密度高，循环性能更优异。As can be seen from Table 5, when the electrolyte concentration is 1 mol/L, the specific capacity of the battery is high, the energy density is high, and the cycle performance is more excellent.

实施例79-122Examples 79-122

实施例79-122与实施例1的区别仅在于，电解液中的添加剂种类不同，具体表6所示，将上述实施例所得的二次电池进行恒电流充放电测试，其测试结果如表6所示：The difference between the embodiment 79-122 and the embodiment 1 is only that the type of the additive in the electrolyte is different. As shown in detail in Table 6, the secondary battery obtained in the above embodiment is subjected to a constant current charge and discharge test, and the test results are shown in Table 6. Shown as follows:

表6Table 6

从表6中可以看出，电解液添加剂为氟代碳酸乙烯酯时，电池的能量密度更高，且循环性能更优异。As can be seen from Table 6, when the electrolyte additive is fluoroethylene carbonate, the energy density of the battery is higher and the cycle performance is more excellent.

实施例123-126Examples 123-126

实施例123-126与实施例1的区别仅在于，电解液中的添加剂质量含量不同，具体表7所示，将上述实施例所得的二次电池进行恒电流充放电测试，其测试结果如表7所示： The difference between the examples 123-126 and the embodiment 1 is only that the mass content of the additive in the electrolyte is different. As shown in detail in Table 7, the secondary battery obtained in the above embodiment is subjected to a constant current charge and discharge test, and the test results are shown in the table. 7 shows:

表7Table 7

从表7中可以看出，添加剂质量含量在5％时，电池的能量密度更高，且循环性能更优异。As can be seen from Table 7, when the additive mass content is 5%, the energy density of the battery is higher and the cycle performance is more excellent.

实施例127-177Examples 127-177

实施例127-177与实施例1的区别仅在于，电解液溶剂种类的不同，具体表8所示，将上述实施例所得的二次电池进行恒电流充放电测试，其测试结果如表8所示：Examples 127-177 differ from Example 1 only in the difference in the solvent type of the electrolyte. As shown in Table 8, the secondary battery obtained in the above examples was subjected to a constant current charge and discharge test. The test results are shown in Table 8. Show:

表8Table 8

从表8中可以看出，电解液溶剂为碳酸乙烯酯+碳酸甲乙酯+碳酸二甲酯时，电池的能量密度更高，且循环性能更优异。As can be seen from Table 8, when the electrolyte solvent is ethylene carbonate + ethyl methyl carbonate + dimethyl carbonate, the energy density of the battery is higher and the cycle performance is more excellent.

本发明实施例涉及的二次电池形态不局限于扣式电池，也可根据核心成分设计成平板电池、圆柱电池等形态。本发明实施例的二次电池主要活性成分为 可供钾盐阴离子脱出与嵌入的材料，且电池体系中无需负极活性材料，因而可显著降低电池自重和制备成本，提升电池能量密度，同时该电池具有优异的循环稳定性能，在二次电池领域具有广阔的应用前景。 The secondary battery according to the embodiment of the present invention is not limited to the button battery, and may be designed in the form of a flat battery or a cylindrical battery according to the core component. The main active ingredient of the secondary battery of the embodiment of the invention is It can be used for the extraction and embedding of potassium anions, and the negative electrode active material is not needed in the battery system, so the battery weight and preparation cost can be significantly reduced, the energy density of the battery can be improved, and the battery has excellent cycle stability performance in the field of secondary batteries. with broadly application foreground.

Claims (15)

1. 一种二次电池，其特征在于，包括：A secondary battery, comprising:

   正极，包括正极集流体和设置在所述正极集流体上的正极活性材料层，所述正极活性材料层包括正极活性材料，所述正极活性材料包括可嵌入钾盐阴离子的材料；a positive electrode comprising a cathode current collector and a cathode active material layer disposed on the cathode current collector, the cathode active material layer comprising a cathode active material, the cathode active material comprising a material capable of intercalating a potassium salt anion;

   电解液，包括钾盐和非水溶剂；An electrolyte comprising a potassium salt and a non-aqueous solvent;

   负极，包括金属箔片，所述金属箔片同时作为负极集流体和负极活性材料；a negative electrode comprising a metal foil, the metal foil simultaneously serving as a negative current collector and a negative active material;

   以及隔膜，所述隔膜介于所述正极与所述负极之间。And a separator interposed between the positive electrode and the negative electrode.
2. 如权利要求1所述的二次电池，其特征在于，所述正极活性材料包括碳材料、硫化物、氮化物、氧化物、碳化物、以及上述各材料的复合物中的一种或多种。The secondary battery according to claim 1, wherein said positive electrode active material comprises one or more of a carbon material, a sulfide, a nitride, an oxide, a carbide, and a composite of each of the above materials. .
3. 如权利要求2所述的二次电池，其特征在于，所述碳材料包括石墨类碳材料、玻璃碳、碳碳复合材料、碳纤维、硬碳、多孔炭、炭黑、碳纳米管、石墨烯中的一种或多种。The secondary battery according to claim 2, wherein said carbon material comprises graphite-based carbon material, vitreous carbon, carbon-carbon composite material, carbon fiber, hard carbon, porous carbon, carbon black, carbon nanotube, graphene One or more of them.
4. 如权利要求3所述的二次电池，其特征在于，所述石墨类碳材料包括天然石墨、膨胀石墨、人造石墨、中间相碳微球石墨、热解石墨、高取向石墨、三维石墨海绵中的一种或多种。The secondary battery according to claim 3, wherein the graphite-based carbon material comprises natural graphite, expanded graphite, artificial graphite, mesocarbon microbead graphite, pyrolytic graphite, highly oriented graphite, and three-dimensional graphite sponge. One or more.
5. 如权利要求2所述的二次电池，其特征在于，所述硫化物选自二硫化钼、二硫化钨、二硫化钒、二硫化钛、二硫化铁、硫化亚铁、硫化镍、硫化锌、硫化钴、硫化锰中的一种或多种；所述氮化物选自六方氮化硼、碳掺杂六方氮化硼中的一种或多种；所述氧化物选自三氧化钼、三氧化钨、五氧化二钒、二氧化钒、二氧化钛、氧化锌、氧化铜、氧化镍、氧化锰中的一种或多种；所述碳 化物选自碳化钛、碳化钽、碳化钼、碳化硅中的一种或多种。The secondary battery according to claim 2, wherein said sulfide is selected from the group consisting of molybdenum disulfide, tungsten disulfide, vanadium disulfide, titanium disulfide, iron disulfide, ferrous sulfide, nickel sulfide, and zinc sulfide. One or more of cobalt sulfide, manganese sulfide; the nitride is selected from one or more of hexagonal boron nitride and carbon doped hexagonal boron nitride; the oxide is selected from the group consisting of molybdenum trioxide, One or more of tungsten trioxide, vanadium pentoxide, vanadium dioxide, titanium dioxide, zinc oxide, copper oxide, nickel oxide, manganese oxide; The compound is selected from one or more of titanium carbide, tantalum carbide, molybdenum carbide, and silicon carbide.
6. 如权利要求1所述的二次电池，其特征在于，所述金属箔片的材质包括锡、锌、铅、锑、镉、金、铋、锗中的任意一种，或含有至少一种上述金属元素的合金，或含有至少一种上述金属元素的复合材料。The secondary battery according to claim 1, wherein the material of the metal foil comprises any one of tin, zinc, lead, antimony, cadmium, gold, bismuth, antimony, or at least one of the above. An alloy of metal elements or a composite material containing at least one of the above metal elements.
7. 如权利要求1所述的二次电池，其特征在于，所述正极集流体的材质包括铝、铜、铁、锡、锌、镍、钛、锰中的任意一种，或含有至少一种上述金属元素的合金，或含有至少一种上述金属元素的复合材料。The secondary battery according to claim 1, wherein the material of the positive electrode current collector comprises any one of aluminum, copper, iron, tin, zinc, nickel, titanium, manganese, or at least one of the above. An alloy of metal elements or a composite material containing at least one of the above metal elements.
8. 如权利要求1所述的二次电池，其特征在于，所述钾盐包括六氟磷酸钾、氯化钾、氟化钾、硫酸钾、碳酸钾、磷酸钾、硝酸钾、二氟草酸硼酸钾、焦磷酸钾、十二烷基苯磺酸钾、十二烷基硫酸钾、柠檬酸三钾、偏硼酸钾、硼酸钾、钼酸钾、钨酸钾、溴化钾、亚硝酸钾、碘酸钾、碘化钾、硅酸钾、木质素磺酸钾、草酸钾、铝酸钾、甲基磺酸钾、醋酸钾、重铬酸钾、六氟砷酸钾、四氟硼酸钾、高氯酸钾、三氟甲烷磺酰亚胺钾、三氟甲基磺酸钾中的一种或多种；所述电解液中，钾盐的浓度为0.1-10mol/L。The secondary battery according to claim 1, wherein said potassium salt comprises potassium hexafluorophosphate, potassium chloride, potassium fluoride, potassium sulfate, potassium carbonate, potassium phosphate, potassium nitrate, potassium difluorooxalate borate , potassium pyrophosphate, potassium dodecylbenzenesulfonate, potassium lauryl sulfate, tripotassium citrate, potassium metaborate, potassium borate, potassium molybdate, potassium tungstate, potassium bromide, potassium nitrite, iodine Potassium acid, potassium iodide, potassium silicate, potassium lignosulfonate, potassium oxalate, potassium aluminate, potassium methanesulfonate, potassium acetate, potassium dichromate, potassium hexafluoroarsenate, potassium tetrafluoroborate, potassium perchlorate, One or more of potassium trifluoromethanesulfonimide and potassium trifluoromethanesulfonate; wherein the concentration of the potassium salt in the electrolyte is from 0.1 to 10 mol/L.
9. 如权利要求1所述的二次电池，其特征在于，所述非水溶剂包括有机溶剂和离子液体，所述有机溶剂包括酯类、砜类、醚类、腈类有机溶剂中的一种或多种。The secondary battery according to claim 1, wherein the nonaqueous solvent comprises an organic solvent and an ionic liquid, and the organic solvent comprises one of an ester, a sulfone, an ether, and a nitrile organic solvent. A variety.
10. 如权利要求9所述的二次电池，其特征在于，所述有机溶剂包括碳酸丙烯酯、碳酸乙烯酯、碳酸二乙酯、碳酸二甲酯、碳酸甲乙酯、甲酸甲酯、乙酸甲酯、N,N-二甲基乙酰胺、氟代碳酸乙烯酯、丙酸甲酯、丙酸乙酯、乙酸乙酯、γ-丁内酯、四氢呋喃、2-甲基四氢呋喃、1,3-二氧环戊烷、4-甲基-1,3-二氧环戊烷、二甲氧甲烷、1,2-二甲氧丙烷、三乙二醇二甲醚、二甲基砜、二甲醚、亚硫酸乙烯酯、亚硫酸丙烯脂、亚硫酸二甲脂、亚硫酸二乙脂、冠醚(12-冠-4) 中的一种或多种。The secondary battery according to claim 9, wherein said organic solvent comprises propylene carbonate, ethylene carbonate, diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, methyl formate, methyl acetate , N,N-dimethylacetamide, fluoroethylene carbonate, methyl propionate, ethyl propionate, ethyl acetate, γ-butyrolactone, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-two Oxycyclopentane, 4-methyl-1,3-dioxocyclopentane, dimethoxymethane, 1,2-dimethoxypropane, triethylene glycol dimethyl ether, dimethyl sulfone, dimethyl ether , vinyl sulfite, propylene sulfite, dimethyl sulfite, diethyl sulfite, crown ether (12-crown-4) One or more of them.
11. 如权利要求9所述的二次电池，其特征在于，所述离子液体包括1-乙基-3-甲基咪唑-六氟磷酸盐、1-乙基-3-甲基咪唑-四氟硼酸盐、1-乙基-3-甲基咪唑-双三氟甲基磺酰亚胺盐、1-丙基-3-甲基咪唑-六氟磷酸盐、1-丙基-3-甲基咪唑-四氟硼酸盐、1-丙基-3-甲基咪唑-双三氟甲基磺酰亚胺盐、1-丁基-1-甲基咪唑-六氟磷酸盐、1-丁基-1-甲基咪唑-四氟硼酸盐、1-丁基-1-甲基咪唑-双三氟甲基磺酰亚胺盐、N-丁基-N-甲基吡咯烷-双三氟甲基磺酰亚胺盐、1-丁基-1-甲基吡咯烷-双三氟甲基磺酰亚胺盐、N-甲基-N-丙基吡咯烷-双三氟甲基磺酰亚胺盐、N-甲,丙基哌啶-双三氟甲基磺酰亚胺盐、N-甲,丁基哌啶-双三氟甲基磺酰亚胺盐中的一种或多种。The secondary battery according to claim 9, wherein said ionic liquid comprises 1-ethyl-3-methylimidazole-hexafluorophosphate, 1-ethyl-3-methylimidazole-tetrafluoroboron Acid salt, 1-ethyl-3-methylimidazole-bistrifluoromethylsulfonimide salt, 1-propyl-3-methylimidazole-hexafluorophosphate, 1-propyl-3-methyl Imidazole-tetrafluoroborate, 1-propyl-3-methylimidazole-bistrifluoromethylsulfonimide salt, 1-butyl-1-methylimidazole-hexafluorophosphate, 1-butyl 1-methylimidazole-tetrafluoroborate, 1-butyl-1-methylimidazole-bistrifluoromethylsulfonimide salt, N-butyl-N-methylpyrrolidine-bistrifluoro Methylsulfonimide salt, 1-butyl-1-methylpyrrolidine-bistrifluoromethylsulfonimide salt, N-methyl-N-propylpyrrolidine-bistrifluoromethylsulfonyl One or more of an imine salt, N-methyl, propyl piperidine-bistrifluoromethylsulfonimide salt, N-methyl, butyl piperidine-bistrifluoromethylsulfonimide salt .
12. 如权利要求1所述的二次电池，其特征在于，所述电解液中还包括添加剂，所述添加剂包括酯类、砜类、醚类、腈类和烯烃类有机添加剂中的一种或多种，所述添加剂在所述电解液中的质量分数为0.1-20％。The secondary battery according to claim 1, wherein said electrolyte further comprises an additive comprising one or more of an ester, a sulfone, an ether, a nitrile, and an olefin organic additive. The mass fraction of the additive in the electrolyte is from 0.1 to 20%.
13. 如权利要求12所述的二次电池，其特征在于，所述添加剂包括氟代碳酸乙烯酯、碳酸亚乙烯酯、碳酸乙烯亚乙酯、1,3-丙磺酸内酯、1,4-丁磺酸内酯、硫酸乙烯酯、硫酸丙烯酯、硫酸亚乙酯、亚硫酸乙烯酯、亚硫酸丙烯酯、二甲基亚硫酸酯、二乙基亚硫酸酯、亚硫酸亚乙酯、氯代甲酸甲脂、二甲基亚砜、苯甲醚、乙酰胺、二氮杂苯、间二氮杂苯、冠醚12-冠-4、冠醚18-冠-6、4-氟苯甲醚、氟代链状醚、二氟代甲基碳酸乙烯酯、三氟代甲基碳酸乙烯酯、氯代碳酸乙烯酯、溴代碳酸乙烯酯、三氟乙基膦酸、溴代丁内酯、氟代乙酸基乙烷、磷酸酯、亚磷酸酯、磷腈、乙醇胺、碳化二甲胺、环丁基砜、1,3-二氧环戊烷、乙腈、长链烯烃、三氧化二铝、氧化镁、氧化钡、碳酸钠、碳酸钙、二氧化碳、二氧化硫、碳酸锂中的一种或多种。 The secondary battery according to claim 12, wherein said additive comprises fluoroethylene carbonate, vinylene carbonate, ethylene carbonate, 1,3-propane sultone, 1,4- Butane sultone, vinyl sulphate, propylene sulfate, ethylene sulphate, vinyl sulfite, propylene sulfite, dimethyl sulfite, diethyl sulfite, ethylene sulfite, chlorine Methyl formate, dimethyl sulfoxide, anisole, acetamide, diazabenzene, m-diazabenzene, crown ether 12-crown-4, crown ether 18-crown-6, 4-fluorobenzate Ether, fluorinated chain ether, difluoromethyl ethylene carbonate, trifluoromethyl ethylene carbonate, vinyl chlorocarbonate, vinyl bromoacetate, trifluoroethylphosphonic acid, bromobutyrolactone , fluoroacetoxyethane, phosphate, phosphite, phosphazene, ethanolamine, dimethylamine, cyclobutylsulfone, 1,3-dioxolane, acetonitrile, long-chain olefin, aluminum oxide One or more of magnesium oxide, cerium oxide, sodium carbonate, calcium carbonate, carbon dioxide, sulfur dioxide, and lithium carbonate.
14. 如权利要求1所述的二次电池，其特征在于，所述隔膜为绝缘的多孔聚合物薄膜或无机多孔薄膜。The secondary battery according to claim 1, wherein the separator is an insulating porous polymer film or an inorganic porous film.
15. 一种二次电池的制备方法，其特征在于，包括以下步骤：A method for preparing a secondary battery, comprising the steps of:

    提供正极集流体，在所述正极集流体上制备正极活性材料层，干燥、压制后裁切成所需尺寸，得到正极；所述正极活性材料层包括正极活性材料，所述正极活性材料包括可嵌入钾盐阴离子的材料；Providing a positive electrode current collector, preparing a positive electrode active material layer on the positive electrode current collector, drying, pressing, and cutting into a desired size to obtain a positive electrode; the positive electrode active material layer including a positive electrode active material, the positive electrode active material including a material embedded with a potassium salt anion;

    将金属箔片裁切成所需的尺寸，经表面清洗、干燥后，得到负极；所述金属箔片同时作为负极集流体和负极活性材料；Cutting the metal foil into a desired size, after surface cleaning and drying, obtaining a negative electrode; the metal foil simultaneously serving as a negative current collector and a negative active material;

    提供电解液和隔膜，所述电解液包括钾盐和非水溶剂，在惰性气体或无水环境下，将所述负极、隔膜、正极依次紧密堆叠，加入所述电解液使所述隔膜完全浸润，然后将上述堆叠部分封装入电池壳体，得到二次电池。 Providing an electrolyte and a separator, the electrolyte comprising a potassium salt and a non-aqueous solvent, wherein the anode, the separator, and the cathode are sequentially closely packed in an inert gas or an anhydrous environment, and the electrolyte is added to completely infiltrate the separator Then, the above stacked portion is packaged into a battery case to obtain a secondary battery.

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