Disclosure of Invention
Therefore, there is a need to provide a novel sodium ion secondary battery with excellent electrochemical performance, long cycle life, high capacity retention rate, relatively high capacity and simple process, which overcomes the drawbacks of the prior art.
In order to achieve the purpose, the invention adopts the following technical scheme:
the utility model provides a novel secondary battery, is including the negative pole current collector layer, negative pole active material layer, electrolyte, anodal active material layer and the positive pole current collector layer that set gradually, be equipped with the diaphragm in the electrolyte, the electrolyte includes electrolyte sodium salt, anodal active material layer includes anodal active material, anodal active material is the Na that can allow free embedding of sodium ion and deviate from2M2(C2O4)3·2H2O material, M is at least one of Co, Ni and Mn.
In some preferred embodiments, the negative current collector layer is a metal conductive material, and the metal conductive material is one of aluminum, tin, zinc, lead, antimony, cadmium, gold, bismuth and germanium or an alloy or composite material formed by the above materials.
In some preferred embodiments, the negative active material layer includes a negative active material that is at least one of artificial graphite, natural graphite, spherulitic graphite, crystalline flake graphite, MCMB, soft carbon, hard carbon, graphite fluoride, mesocarbon microbeads, petroleum coke, carbon brazes, pyrolytic resin carbon, tin-based alloys, silicon-based alloys, germanium-based alloys, aluminum-based alloys, antimony-based alloys, magnesium-based alloys, carbon nanotubes, nanoalloy materials, nanooxide materials, triiron tetroxide, trimong tetroxide, alpha-ferric oxide, molybdenum oxide, tungsten oxide, vanadium oxide, cobalt oxide, manganese oxide, titanium nitride, vanadium nitride, tungsten oxynitride, nickel sulfide, and vanadium sulfide.
In some preferred embodiments, the negative active material layer further includes a conductive agent and a binder, the conductive agent is one or more of conductive carbon black, conductive carbon spheres, conductive graphite, carbon nanotubes, conductive carbon fibers, graphene and reduced graphene oxide, and the binder is one or more of polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl alcohol, carboxymethyl cellulose, SBR rubber and polyolefin.
In some preferred embodiments, the content of the negative active material is 60 to 90 wt%, the content of the conductive agent is 5 to 30 wt%, and the content of the binder is 5 to 10 wt%.
In some preferred embodiments, the electrolyte sodium salt comprises one or more of sodium perchlorate, sodium hexafluorophosphate, sodium chloride, sodium fluoride, sodium sulfate, sodium carbonate, sodium phosphate, sodium nitrate, sodium difluorooxalate, sodium pyrophosphate, sodium dodecylbenzenesulfonate, sodium dodecylsulfate, trisodium citrate, sodium metaborate, sodium borate, sodium molybdate, sodium tungstate, sodium bromide, sodium nitrite, sodium iodate, sodium iodide, sodium silicate, sodium lignosulfonate, sodium oxalate, sodium aluminate, sodium methylsulfonate, sodium acetate, sodium dichromate, sodium hexafluoroarsenate, sodium tetrafluoroborate, sodium trifluoromethanesulfonimide, or sodium trifluoromethanesulfonate, and the concentration of the electrolyte sodium salt is in the range of 0.1-10 mol/L.
In some preferred embodiments, the electrolyte further comprises an electrolyte solvent comprising Propylene Carbonate (PC), Ethylene Carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), Ethyl Methyl Carbonate (EMC), Methyl Formate (MF), Methyl Acetate (MA), 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-Dioxolane (DOL), 4-methyl-1, 3-dioxolane (4MeDOL), Dimethoxymethane (DMM), 1, 2-Dimethoxypropane (DMP), triethylene glycol dimethyl ether (DG), dimethylsulfone (MSM), and mixtures thereof, Dimethyl ether (DME), vinyl sulfite (ES), Propylene Sulfite (PS), dimethyl sulfite (DMS), diethyl sulfite (DES), crown ether (12-crown-4), 1-ethyl-3-methylimidazole-hexafluorophosphate, 1-ethyl-3-methylimidazole-tetrafluoroborate, 1-ethyl-3-methylimidazole-bistrifluoromethylsulfonyl imide salt, 1-propyl-3-methylimidazole-hexafluorophosphate, 1-propyl-3-methylimidazole-tetrafluoroborate, 1-propyl-3-methylimidazole-bistrifluoromethylsulfonyl imide salt, 1-butyl-1-methylimidazole-hexafluorophosphate, 1-butyl-1-methylimidazole-tetrafluoroborate, propylene glycol, 1-butyl-1-methylimidazole-bis (trifluoromethyl) sulfonyl imide salt, N-butyl-N-methylpyrrolidine-bis (trifluoromethyl) sulfonyl imide salt, 1-butyl-1-methylpyrrolidine-bis (trifluoromethyl) sulfonyl imide salt, N-methyl-N-propyl pyrrolidine-bis (trifluoromethyl) sulfonyl imide salt, N-methyl, propyl piperidine-bis (trifluoromethyl) sulfonyl imide salt, N-methyl, butyl piperidine-bis (trifluoromethyl) sulfonyl imide salt.
In some preferred embodiments, the electrolyte further comprises an additive comprising fluoroethylene carbonate, vinylene carbonate, ethylene carbonate, 1, 3-propane sultone, 1, 4-butane sultone, vinyl sulfate, propylene sulfate, ethylene sulfite, propylene sulfite, dimethyl sulfite, diethyl sulfite, ethylene sulfite, methyl chloroformate, dimethyl sulfoxide, anisole, acetamide, diazabenzene, m-diazabenzene, crown ether 12-crown-4, crown ether 18-crown-6, 4-fluorophenylmethyl ether, fluoro chain ether, vinyl difluoromethyl carbonate, vinyl trifluoromethylcarbonate, vinyl chlorocarbonate, vinyl bromocarbonate, trifluoroethylphosphonic acid, bromo-butyrolactone, fluoroacetoxyethane, fluoroethylene, methyl sulfite, ethyl sulfite, methyl sulfite, dimethyl sulfoxide, anisole, acetamide, diazabenzene, m-diazabenzene, crown ether 12-crown-4, crown-6, 4-fluorophenylmethyl ether, fluoro, Phosphate, phosphite ester, phosphazene, ethanolamine, carbonized dimethylamine, cyclobutyl sulfone, 1, 3-dioxolane, acetonitrile, long-chain olefin, aluminum oxide, magnesium oxide, barium oxide, sodium carbonate, calcium carbonate, carbon dioxide, sulfur dioxide and one or more of lithium carbonate.
In some preferred embodiments, the positive active material layer further includes a conductive agent and a binder, the conductive agent is one or more of conductive carbon black, conductive carbon spheres, conductive graphite, carbon nanotubes, conductive carbon fibers, graphene and reduced graphene oxide, and the binder is one or more of polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl alcohol, carboxymethyl cellulose, SBR rubber and polyolefins.
In some preferred embodiments, the content of the positive electrode active material is 60 to 90 wt%, the content of the conductive agent is 5 to 30 wt%, and the content of the binder is 5 to 10 wt%.
In some preferred embodiments, the positive current collector layer comprises one of aluminum, copper, iron, tin, zinc, nickel, titanium, manganese, lead, antimony, cadmium, gold, bismuth, germanium, or alloys or composites thereof.
In some preferred embodiments, the separator is an insulating porous polymer film or an inorganic porous film, the porous polymer film is one or more of a porous polypropylene film, a porous polyethylene film or a porous composite polymer film, and the inorganic porous film is one or more of a glass fiber paper or a porous ceramic separator.
In addition, the invention also provides a preparation method of the secondary battery, which comprises the following steps:
uniformly coating the negative electrode active material layer on the surface of the negative electrode current collector layer, and cutting after the negative electrode active material layer is dried to obtain the battery negative electrode;
cleaning a positive current collector layer, uniformly coating the positive active material layer on the surface of the positive current collector layer, and cutting after the positive active material layer is dried to obtain the battery positive electrode;
assembling the battery cathode, the electrolyte, the diaphragm and the battery anode to obtain the secondary battery;
the electrolyte comprises electrolyte, the electrolyte comprises electrolyte sodium salt, the positive active material layer comprises positive active material, and the positive active material is Na capable of allowing sodium ions to be freely inserted and extracted2M2(C2O4)3·2H2O material, M is at least one of Co, Ni and Mn.
The invention adopts the technical scheme that the method has the advantages that:
the novel secondary battery comprises a negative electrode current collector layer, a negative electrode active material layer, electrolyte, a positive electrode active material layer and a positive electrode current collector layer which are sequentially arranged, wherein a diaphragm is arranged in the electrolyte, the electrolyte comprises electrolyte, the electrolyte is electrolyte sodium salt, the positive electrode active material layer comprises a positive electrode active material, and the positive electrode active material is Na which can allow sodium ions to be freely embedded and removed2M2(C2O4)3·2H2O material, M is Co, Ni, Mn or moreOne of the sodium ions is removed from the positive active material and moves into the electrolyte in the charging process of the novel secondary battery, the sodium ions in the electrolyte migrate to the negative electrode, the valence of the transition metal is changed from +2 to +3, and the generated free electrons move to the negative electrode through an external circuit to balance the positive charges carried by the sodium ions; in the discharging process, sodium ions are separated from the negative electrode material and return to the electrolyte, the sodium ions in the electrolyte return to the positive electrode material, and free electrons return to the positive electrode material through an external circuit, so that the whole charging and discharging process is realized. Because the lithium-free material is not contained, the lithium-free lithium ion battery is not limited by lithium resources, the battery can be developed greatly, and the production cost is obviously reduced. Compared with the existing sodium ion battery, the battery has the advantages of excellent electrochemical performance, long cycle service life, high capacity retention rate, high capacity, simple and easily-obtained anode and cathode materials and environmental protection, so that the production process of the full battery is simple and the cost is low.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Fig. 1 is a schematic structural diagram of a novel secondary battery according to an embodiment of the present invention, and for convenience of description, only the portions related to the embodiment of the present invention are shown, which is described in detail below.
The present invention provides a novel secondary battery 100 including: the negative current collector layer 1, the negative active material layer 2, the electrolyte 3, the positive active material layer 5 and the positive current collector layer 6 that set gradually, be equipped with diaphragm 4 in the electrolyte 3 layer.
Specifically, the electrolytic solution 3 includes an electrolyte including an electrolyte sodium salt.
The invention can be understood that sodium salt with abundant reserves and low price is taken as the electrolyte of the sodium ion secondary battery, thereby not only reducing the cost of the battery, but also not causing dendrites to pierce the diaphragm in the reaction process and having better safety performance.
The positive active material layer comprises a positive active material which is Na capable of allowing sodium ions to be freely inserted and extracted2M2(C2O4)3·2H2O material, M is at least one of Co, Ni and Mn.
The composition of the substances included in each layer is described in detail below.
In some preferred embodiments, the negative current collector layer 1 is a metal conductive material, and the metal conductive material is one of aluminum, tin, zinc, lead, antimony, cadmium, gold, bismuth and germanium, or an alloy or a composite material formed by the above materials.
Further, the negative current collector layer is aluminum.
In some preferred embodiments, the negative active material layer 2 includes a negative active material that is at least one of artificial graphite, natural graphite, spherulitic graphite, crystalline flake graphite, MCMB, soft carbon, hard carbon, graphite fluoride, mesocarbon microbeads, petroleum coke, carbon fibrils, pyrolytic resin carbon, tin-based alloys, silicon-based alloys, germanium-based alloys, aluminum-based alloys, antimony-based alloys, magnesium-based alloys, carbon nanotubes, nano-alloy materials, nano-oxide materials, triiron tetroxide, trimong tetroxide, α -ferric oxide, molybdenum oxide, tungsten oxide, vanadium oxide, cobalt oxide, manganese oxide, titanium nitride, vanadium nitride, tungsten oxynitride, nickel sulfide, and vanadium sulfide.
Further, in some preferred embodiments, the negative active material layer 2 further includes a conductive agent and a binder, the conductive agent is one or more of conductive carbon black, conductive carbon spheres, conductive graphite, carbon nanotubes, conductive carbon fibers, graphene and reduced graphene oxide, and the binder is one or more of polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl alcohol, carboxymethyl cellulose, SBR rubber and polyolefins.
In some preferred embodiments, the content of the negative active material is 60 to 90 wt%, the content of the conductive agent is 5 to 30 wt%, and the content of the binder is 5 to 10 wt%.
In some preferred embodiments, the electrolyte sodium salt comprises one or more of sodium perchlorate, sodium hexafluorophosphate, sodium chloride, sodium fluoride, sodium sulfate, sodium carbonate, sodium phosphate, sodium nitrate, sodium difluorooxalate, sodium pyrophosphate, sodium dodecylbenzenesulfonate, sodium dodecylsulfate, trisodium citrate, sodium metaborate, sodium borate, sodium molybdate, sodium tungstate, sodium bromide, sodium nitrite, sodium iodate, sodium iodide, sodium silicate, sodium lignosulfonate, sodium oxalate, sodium aluminate, sodium methylsulfonate, sodium acetate, sodium dichromate, sodium hexafluoroarsenate, sodium tetrafluoroborate, sodium trifluoromethanesulfonimide, or sodium trifluoromethanesulfonate, and the concentration of the electrolyte sodium salt is in the range of 0.1-10 mol/L.
More further, the concentration of the sodium salt of the electrolyte is in the range of 0.5 to 1mol/L, for example 0.5mol/L, 0.7mol/L, or 1 mol/L.
In some preferred embodiments, the electrolyte 3 further comprises an electrolyte solvent including Propylene Carbonate (PC), Ethylene Carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), Ethyl Methyl Carbonate (EMC), Methyl Formate (MF), Methyl Acetate (MA), 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-Dioxolane (DOL), 4-methyl-1, 3-dioxolane (4MeDOL), Dimethoxymethane (DMM), 1, 2-Dimethoxypropane (DMP), triethylene glycol dimethyl ether (DG), dimethylsulfone (MSM), and dimethylsulfone (MSM), Dimethyl ether (DME), vinyl sulfite (ES), Propylene Sulfite (PS), dimethyl sulfite (DMS), diethyl sulfite (DES), crown ether (12-crown-4), 1-ethyl-3-methylimidazole-hexafluorophosphate, 1-ethyl-3-methylimidazole-tetrafluoroborate, 1-ethyl-3-methylimidazole-bistrifluoromethylsulfonyl imide salt, 1-propyl-3-methylimidazole-hexafluorophosphate, 1-propyl-3-methylimidazole-tetrafluoroborate, 1-propyl-3-methylimidazole-bistrifluoromethylsulfonyl imide salt, 1-butyl-1-methylimidazole-hexafluorophosphate, 1-butyl-1-methylimidazole-tetrafluoroborate, propylene glycol, 1-butyl-1-methylimidazole-bis (trifluoromethyl) sulfonyl imide salt, N-butyl-N-methylpyrrolidine-bis (trifluoromethyl) sulfonyl imide salt, 1-butyl-1-methylpyrrolidine-bis (trifluoromethyl) sulfonyl imide salt, N-methyl-N-propyl pyrrolidine-bis (trifluoromethyl) sulfonyl imide salt, N-methyl, propyl piperidine-bis (trifluoromethyl) sulfonyl imide salt, N-methyl, butyl piperidine-bis (trifluoromethyl) sulfonyl imide salt.
In some preferred embodiments, the electrolyte 3 further comprises an additive comprising fluoroethylene carbonate, vinylene carbonate, ethylene carbonate, 1, 3-propane sultone, 1, 4-butane sultone, ethylene sulfate, propylene sulfate, ethylene sulfite, propylene sulfite, dimethyl sulfite, diethyl sulfite, ethylene sulfite, methyl chloroformate, dimethyl sulfoxide, anisole, acetamide, diazabenzene, m-diazabenzene, crown ether 12-crown-4, crown ether 18-crown-6, 4-fluorophenylmethyl ether, fluoro chain ether, vinyl difluoromethyl carbonate, vinyl trifluoromethylcarbonate, vinyl chlorocarbonate, vinyl bromocarbonate, trifluoroethyl phosphonic acid, bromo butyrolactone, fluoroacetoxyethane, fluoro alkyl ether, and mixtures thereof, Phosphate, phosphite ester, phosphazene, ethanolamine, carbonized dimethylamine, cyclobutyl sulfone, 1, 3-dioxolane, acetonitrile, long-chain olefin, aluminum oxide, magnesium oxide, barium oxide, sodium carbonate, calcium carbonate, carbon dioxide, sulfur dioxide and one or more of lithium carbonate.
It can be understood that the additive added in the electrolyte can form a stable solid electrolyte membrane on the surface of the negative current collector, thereby improving the service life of the battery.
In some preferred embodiments, the positive active material layer 5 further includes a conductive agent and a binder, the conductive agent is one or more of conductive carbon black, conductive carbon spheres, conductive graphite, carbon nanotubes, conductive carbon fibers, graphene and reduced graphene oxide, and the binder is one or more of polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl alcohol, carboxymethyl cellulose, SBR rubber and polyolefin.
In some preferred embodiments, the content of the positive electrode active material is 60 to 90 wt%, the content of the conductive agent is 5 to 30 wt%, and the content of the binder is 5 to 10 wt%.
In some preferred embodiments, the positive current collector layer 6 includes one or more of aluminum, copper, iron, tin, zinc, nickel, titanium, manganese, lead, antimony, cadmium, gold, bismuth, germanium, or alloys or composites thereof.
Further, the positive current collector layer is aluminum.
In some preferred embodiments, the separator 4 is an insulating porous polymer film or an inorganic porous film, the porous polymer film is one or more of a porous polypropylene film, a porous polyethylene film or a porous composite polymer film, and the inorganic porous film is one or more of a glass fiber paper or a porous ceramic separator.
It can be understood that in the charging process of the novel secondary battery provided by the invention, sodium ions in the positive active material are removed and moved into the electrolyte, the sodium ions in the electrolyte are moved to the negative electrode, the valence of the transition metal is changed from +2 to +3, and the generated free electrons are moved to the negative electrode through an external circuit to balance positive charges carried by the sodium ions; during the discharging process, sodium ions are separated from the negative electrode material and return to the electrolyte, the sodium ions in the electrolyte return to the positive electrode material, and free electrons return to the positive electrode material through an external circuit, so that the whole charging and discharging process is realized. Because the battery does not contain lithium materials and is not limited by lithium resources, the battery can be developed greatly, and the production cost is obviously reduced.
Referring to fig. 2, a flowchart of steps for manufacturing a novel secondary battery according to an embodiment of the present invention includes the following steps:
step S110: uniformly coating the negative electrode active material layer on the surface of the negative electrode current collector layer, and cutting after the negative electrode active material layer is dried to obtain the battery negative electrode;
specifically, the negative electrode active material is weighed according to a certain proportion (a conductive agent and a binder can be added according to the situation), and a proper solvent is added to be fully mixed into uniform slurry to prepare a negative electrode active material layer; cleaning a negative current collector, uniformly coating the negative active material layer on the surface of the negative current collector, and cutting after the negative active material layer is completely dried to obtain the battery negative electrode with the required size;
step S120: cleaning a positive current collector layer, uniformly coating the positive active material layer on the surface of the positive current collector layer, and cutting after the positive active material layer is dried to obtain the battery positive electrode;
specifically, the positive active material Na is weighed according to a certain proportion2M2(C2O4)3·2H2O material, M is at least one of Co, Ni and Mn (conductive agent and binder can be added according to the situation), and proper solvent is added to be fully mixed into uniform slurry to prepare a positive active material layer; cleaning a positive current collector layer, uniformly coating the positive active material layer on the surface of the positive current collector layer, and cutting after the positive active material layer is completely dried to obtain a battery positive electrode with a required size;
step S130: assembling the battery cathode, the electrolyte, the diaphragm and the battery anode to obtain the secondary battery;
the electrolyte comprises electrolyte, the electrolyte comprises electrolyte sodium salt, the positive active material layer comprises positive active material, and the positive active material is Na capable of allowing sodium ions to be freely inserted and extracted2M2(C2O4)3·2H2O material, M is at least one of Co, Ni and Mn.
The material composition of each layer is described in detail above, and is not described herein again.
In the charging process of the novel secondary battery, sodium ions in the positive active material are removed and moved into electrolyte, the sodium ions in the electrolyte are moved to the negative electrode, the valence of the transition metal is changed from +2 to +3, and the generated free electrons are moved to the negative electrode through an external circuit to balance positive charges carried by the sodium ions; in the discharging process, sodium ions are separated from the negative electrode material and return to the electrolyte, the sodium ions in the electrolyte return to the positive electrode material, and free electrons return to the positive electrode material through an external circuit, so that the whole charging and discharging process is realized.
The preparation method of the novel secondary battery provided by the embodiment of the invention has the advantages of simple production process and low cost, and compared with the existing sodium ion battery, the novel secondary battery has the advantages of excellent electrochemical performance, long cycle service life, high capacity retention rate, relatively high capacity, simple and easily available anode and cathode materials and environmental protection.
The above technical solution is described in detail with reference to specific embodiments below.
Example 1: based on Na2Co2(C2O4)3·2H2Sodium ion half-cell of O positive electrode
Preparing a battery cathode: metal sodium is rolled on an aluminum foil (namely, a negative electrode current collector) to form a foil, and the obtained sodium-aluminum composite foil is cut into a circular sheet with the diameter of 12mm to be used as a battery negative electrode for standby.
Preparing a diaphragm: the glass fiber film was cut into a circular sheet having a diameter of 16mm and used as a separator.
Preparing an electrolyte: 0.6122g of sodium perchlorate is weighed and added into 10ml of propylene carbonate solvent, the sodium perchlorate is stirred and completely dissolved, then fluoroethylene carbonate with the mass fraction of 3 percent is added as an additive, and the mixture is fully stirred uniformly and then used as electrolyte for standby.
Preparing a battery positive electrode: 0.8g of Na2Co2(C2O4)3·2H2Adding O crystal powder, 0.1g of conductive agent carbon black and 0.1g of binder polyvinylidene fluoride into 2ml of nitrogen methyl pyrrolidone solution, and fully grinding to obtain uniform slurry; the slurry was then uniformly coated on the aluminum foil surface (i.e., the positive current collector) and vacuum dried. And cutting the dried electrode slice into a wafer with the diameter of 10mm, and compacting the wafer to be used as the battery anode for standby.
Assembling the battery: and (3) in a glove box protected by inert gas, tightly stacking the prepared negative current collector, the diaphragm and the battery positive electrode in sequence, dropwise adding electrolyte to completely soak the diaphragm, and packaging the stacked part into a button battery shell to finish battery assembly.
Fig. 3 is a graph of a stable charge-discharge curve of the battery obtained in this example at 0.2C, and it can be seen from the graph that the discharge capacity of the battery can reach 80 mAh/g.
Fig. 4 is a graph of the long cycle capacity of the battery obtained in this example, from which it can be seen that the capacity remained at about 80mAh/g after 400 cycles, the coulombic efficiency remained close to 98%, the capacity fade was relatively slow, and the cycle life was long.
Examples 2 to 25: based on Na2M2(C2O4)3·2H2Sodium ion full battery with O (Co, Ni, Mn) anode
Preparing a battery cathode: adding a negative electrode active material, a negative electrode conductive agent and a negative electrode binder into 2ml of nitrogen methyl pyrrolidone solution according to a certain ratio (shown in table 1), and fully grinding to obtain uniform slurry; and then uniformly coating the slurry on the surface of the negative current collector and performing vacuum drying. And cutting the dried electrode slice into a wafer with the diameter of 10mm, and compacting the wafer to be used as a battery cathode for standby.
Preparing a diaphragm: the glass fiber film was cut into a circular sheet having a diameter of 16mm and used as a separator.
Preparing an electrolyte: weighing a certain amount of electrolyte salt, adding the electrolyte salt into a certain amount of organic solvent, stirring until the electrolyte salt is completely dissolved, then adding a certain amount of additive, and fully and uniformly stirring to obtain the electrolyte for later use.
Preparing a battery positive electrode: mixing Na2M2(C2O4)3·2H2Adding O (M ═ Co, Ni and Mn) crystal powder, a positive electrode conductive agent and a positive electrode binder into 2ml of nitrogen methyl pyrrolidone solution according to a certain proportion (mass ratio) (see table 1), and fully grinding to obtain uniform slurry; and then uniformly coating the slurry on the surface of the positive current collector and performing vacuum drying. And cutting the dried electrode slice into a wafer with the diameter of 10mm, and compacting the wafer to be used as the battery anode for standby.
Assembling the battery: and (3) in a glove box protected by inert gas, tightly stacking the prepared negative current collector, the diaphragm and the battery positive electrode in sequence, dropwise adding electrolyte to completely soak the diaphragm, and packaging the stacked part into a button battery shell to finish battery assembly.
Table 1: performance parameter Table of sodium ion Secondary batteries of examples 2 to 25 of the present invention
The secondary battery according to the present invention may be designed in the form of a flat battery, a cylindrical battery, or the like, depending on the core components, without being limited to a button battery.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
Of course, the novel secondary battery of the present invention may have various changes and modifications, and is not limited to the specific structure of the above-described embodiment. In conclusion, the scope of the present invention should include those changes or substitutions and modifications which are obvious to those of ordinary skill in the art.