Battery cell and battery

Abstract

The application provides an electric core and a battery. The electric core comprises a bipolar sheet, the bipolar sheet comprises a positive electrode coating, a negative electrode coating, a current collector and an electronic insulation coating; the positive electrode coating and the negative electrode coating are arranged on opposite surfaces of the current collector respectively; and the electronic insulation coating is arranged on the surface of at least one of the positive electrode coating and the negative electrode coating. In this way, the electronic insulation coating can be used to simplify the process flow of the laminated sheet, thereby improving the preparation efficiency of the electric core. Meanwhile, the electronic insulation coating can be used to improve the capacity performance of the battery, thereby improving the energy density of the battery.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a battery cell and a battery. BACKGROUND

[0002] In recent years, the battery technology has developed rapidly, and the industrialization process of sodium-ion batteries is particularly remarkable. Since metal sodium does not react with aluminum current collector at low voltage, aluminum foil can be applied to the sodium-ion negative electrode current collector, so that a bipolar electrode sheet can be designed, that is, the positive electrode material and the negative electrode material are coated on both sides of the same aluminum foil.

[0003] In the prior art, a sodium-ion battery is usually composed of a positive electrode coating, a negative electrode coating, a current collector and an electrolyte. During the first charging process, irreversible sodium ions are lost, resulting in a low energy density of the sodium-ion battery. SUMMARY

[0004] The present application provides a battery cell and a battery to solve the problem of low energy density of the battery caused by the loss of irreversible sodium ions during charging in the prior art.

[0005] The present application provides a battery cell, which comprises a bipolar electrode sheet, the bipolar electrode sheet comprising a positive electrode coating, a negative electrode coating, a current collector and an electronic insulation coating.

[0006] The positive electrode coating and the negative electrode coating are respectively arranged on opposite surfaces of the current collector.

[0007] The electronic insulation coating is arranged on the surface of at least one of the positive electrode coating and the negative electrode coating.

[0008] Optionally, the battery cell comprises N bipolar electrode sheets, the N bipolar electrode sheets being arranged in a vertical direction, the vertical direction being perpendicular to the extension direction of the current collector.

[0009] In the N bipolar electrode sheets, adjacent bipolar electrode sheets are connected by the same electronic insulation layer.

[0010] In the N bipolar electrode sheets, the first electrode sheet and the second electrode sheet are connected to the edge part by the electronic insulation layer, and the edge part comprises one of the following: positive electrode coating plus current collector, negative electrode coating plus current collector.

[0011] The first electrode sheet and the second electrode sheet are the bipolar electrode sheets located at the two ends of the N bipolar electrode sheets, and N is a positive integer greater than 1.

[0012] Optionally, the electronic insulation coating comprises one of the following: solid electrolyte and insulating coating.

[0013] In the case that the electron insulation coating comprises the solid electrolyte, the electron insulation coating is a dense coating structure;

[0014] In the case that the electron insulation coating comprises the insulation coating, the electron insulation coating is a porous structure.

[0015] Optionally, the positive electrode coating comprises a sodium supplementing additive; and / or

[0016] The negative electrode coating comprises a sodium supplementing additive;

[0017] The sodium supplementing additive comprises at least one of sodium oxalate, sodium oxide, sodium peroxide, sodium sulfide, sodium phosphide and a sodium-containing organic compound.

[0018] Optionally, the mass of the sodium supplementing additive is m1, the mass of the positive electrode active material in the positive electrode coating is m2, and m1 and m2 satisfy the following relationship:

[0019] m1:m2 is less than or equal to 1:10;

[0020] m1:m2 is greater than or equal to 1:100.

[0021] Optionally, the thickness of the electron insulation coating is greater than or equal to 4 microns;

[0022] The thickness of the electron insulation coating is less than or equal to 50 microns.

[0023] Optionally, in the case that the electron insulation coating comprises the solid electrolyte, the solid electrolyte further comprises a binder;

[0024] The binder comprises at least one of polyvinylidene fluoride, polytetrafluoroethylene, styrene butadiene rubber, nitrile butadiene rubber, water-based acrylic resin, polyvinyl alcohol, polyvinyl butyral, polyurethane, fluorinated rubber, carboxymethyl cellulose and polyacrylic acid.

[0025] Optionally, in the electron insulation coating, the percentage content of the binder is 1.0wt% to 10.0wt%; and / or

[0026] The porosity of the solid electrolyte is 2% to 50%.

[0027] Optionally, in the case that the electron insulation coating comprises the insulation coating, the pore size of the porous structure ranges from 0.02 microns to 0.15 microns; and / or

[0028] The porosity of the insulation coating is 25% to 70%.

[0029] The embodiments of the present application also provide a battery comprising the above-mentioned battery cell.

[0030] In the embodiment of the present application, by arranging the electronic insulation coating on the opposite sides of the dual-pole sheet, the related process of the laminated sheet is simplified in the process flow of the battery cell manufacturing, and the manufacturing efficiency of the battery cell is improved. In addition, the arrangement of the electronic insulation coating can effectively compensate for the irreversible sodium ions in the first charging process of the battery, thereby improving the capacity of the battery, and further improving the energy density of the sodium ion battery. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0032] Figure 1 is a structural schematic diagram of a battery cell provided by the embodiment of the present application;

[0033] Figure 2 is a structural schematic diagram of a single dual-pole sheet in a battery cell provided by the embodiment of the present application. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0035] The terms "first", "second", and the like in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the structures used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are usually a category, not limited to the number of objects, for example, the first object can be one or more. In addition, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / ", generally indicates that the front and rear associated objects are in an "or" relationship.

[0036] The embodiment of the present application provides a battery cell, as shown in Figure 1 and Figure 2 , which comprises a dual-pole sheet 10, the dual-pole sheet 10 comprising a positive electrode coating 11, a negative electrode coating 12, a current collector 13 and an electronic insulation coating 14;

[0037] The positive electrode coating 11 and the negative electrode coating 12 are respectively arranged on the opposite surfaces of the current collector 13.

[0038] The electronic insulation coating 14 is arranged on the surface of at least one of the positive electrode coating 11 and the negative electrode coating 12.

[0039] In this embodiment, by arranging the electronic insulation coating 14 on both sides of the edge of the bipolar electrode sheet 10, the relevant process of the sheet is simplified in the process flow of the battery cell manufacturing, and the manufacturing efficiency of the battery cell can be improved. In addition, the arrangement of the electronic insulation coating 14 can effectively compensate for the irreversible sodium ions in the first charging process of the battery, thereby improving the capacity of the battery, and further improving the energy density of the sodium ion battery.

[0040] In addition, the bipolar electrode sheet 10 can be added with an electrolyte, and the positive electrode coating 11 and the negative electrode coating 12 can be added with a sodium supplement additive. The addition of the sodium supplement additive can compensate for the irreversible sodium ions in the first charging process of the battery, and the addition of the electrolyte can maintain the normal operation state of the battery.

[0041] It should be understood that the electronic insulation coating 14 can be coated on one side of the positive electrode coating 11, or on one side of the negative electrode coating 12. Of course, the electronic insulation coating 14 can be coated on one side of the positive electrode coating 11, and on one side of the negative electrode coating 12.

[0042] It should be noted that the adjacent bipolar electrode sheets 10 need to be connected by the electronic insulation coating 14. For example, the first bipolar electrode sheet and the second bipolar electrode sheet are two adjacent electrode sheets. When the position of the electronic insulation coating in the first bipolar electrode sheet is arranged away from the second bipolar electrode sheet, the electronic insulation coating of the second bipolar electrode sheet needs to be arranged close to the first bipolar electrode sheet, so that the first bipolar electrode sheet and the second bipolar electrode sheet are connected by the electronic insulation coating.

[0043] Another explanation is that the thickness of the electronic insulation coating 14 can be determined according to the actual required specifications of the battery, and the embodiments of the present application are not limited.

[0044] In addition, the active material in the positive electrode coating 11 can include one or more of Prussian blue type materials, polyanion type materials and transition metal layered oxides, wherein the transition metal layered oxide can be selected from NaCoO2, Na 2 / 3 [Cu 1 / 3 Mn 2 / 3 ]O2, Na 2 / 3 [Fe 1 / 3 Mn 2 / 3 ]O2, Na 2 / 3 [Li 1 / 3 Ni 2 / 3O2, Na[Ni 0.5 Co 0.5 ]O2, Na 7 / 9 [Cu 2 / 9 Fe 1 / 9Mn 2 / 3 ]O2, Na 2 / 3 [Li 1 / 3 Mn 1 / 2 Ti 1 / 6 ]O2, Na[Ni 0.5 Fe 0.5 ]O2, Na[Co 0.5 Fe 0.5 ]O2, Na[Ni 1 / 3 Fe 1 / 3 Mn 1 / 3 ]O2, Na[Cu 1 / 9 Ni 2 / 9 Fe 1 / 3 Mn 1 / 3 ]O2.

[0045] wherein the Prussian blue type material has a chemical formula of A x M[Fe(CN)6] y , A is an alkali metal cation, M is a transition metal cation, 1≤x≤2, 0.9≤y≤1, for example: A can be selected from Li, Na, K, Rb, Cs or Fr, M can be selected from one or more of Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr and Mo.

[0046] Specifically, the Prussian blue type material is selected from one or more of LiFe2(CN)6, LiCoFe(CN)6, LiMnFe(CN)6, NaFe2(CN)6, KFe2(CN)6, NaCuFe(CN)6, NaNiFe(CN)6, Na2Fe2(CN)6, Na2MnFe(CN)6, Na2CoFe(CN)6, Na2NiFe(CN)6.

[0047] wherein the polyanion type material has a chemical formula of A’ x’ M’ y’ (X n’ O m ) z F w , A' is Li or Na, M' is one or more of transition metal ions with variable valence, X is P, S, V or Si, and x'≥1, y'>0, z≥1, w≥0, n' and m take values in accordance with the charge conservation principle.

[0048] Specifically, M' is Ti, Fe or Mn, and the polyanionic material is selected from one or more of NaFePO4, Na3V2(PO4)3, Na2MnP2O7, Na2FeP2O7, Na2FePO4F, etc.

[0049] It should be noted that the average particle size Dv50 of the Prussian blue material is 1-15 microns, and the average particle size Dv50 of the polyanionic material is 1-10 microns.

[0050] After completing the setting of the positive electrode coating 11 on one side of the current collector 13, the setting of the negative electrode coating 12 is then completed on the other opposite side of the current collector 13, wherein the negative electrode active material can be at least one selected from natural graphite, artificial graphite, mesophase microcarbon, hard carbon, soft carbon, Sn, SnO, SnO2, Sb, Sb2O3, Bi, Bi2O3, TiO2.

[0051] Hereinafter, taking the selection of hard carbon and soft carbon as an example:

[0052] The hard carbon can be a carbon material that is difficult to graphitize at a temperature of 2500°C or higher, and the hard carbon can be selected from at least one of resin pyrolytic carbon, organic polymer pyrolytic carbon, pyrolytic carbon black, and biomass pyrolytic carbon, and the organic polymer in the organic polymer pyrolytic carbon can be selected from at least one of polyvinyl alcohol, polyvinyl chloride, polyvinylidene fluoride, and polyacrylonitrile.

[0053] It should be noted that the pyrolytic carbon black can be selected from acetylene black, and the biomass in the biomass pyrolytic carbon is selected from at least one of rice husk, walnut shell, banana peel, pomelo peel, lignin, and coconut shell.

[0054] In addition, the soft carbon refers to amorphous carbon that can be graphitized at a high temperature of 2500°C or higher, and the soft carbon can be selected from at least one of petroleum coke, needle coke, carbon fiber, and carbon microsphere.

[0055] It should be noted that the average particle size Dv50 of the hard carbon can be 5-15 microns, and the average particle size Dv50 of the soft carbon can be 5-15 microns.

[0056] For the current collector 13, the current collector 13 can include one or more of aluminum foil, carbon-coated aluminum foil, perforated aluminum foil, stainless steel foil, polymer substrate coated with conductive metal, and any combination thereof.

[0057] Optionally, the battery cell includes N bipolar plates, which are sequentially stacked in a vertical direction, and the vertical direction is perpendicular to the direction in which the current collector 13 extends.

[0058] In the N double-pole pieces, and adjacent double-pole pieces are connected by the same electronic insulating layer.

[0059] In the N double-pole pieces, the first pole piece 15 and the second pole piece 16 are connected with the edge part 20 through the electronic insulating layer, and the edge part 20 includes one of the following: positive electrode coating plus current collector, negative electrode coating plus current collector;

[0060] Wherein, the first pole piece 15 and the second pole piece 16 are the double-pole pieces located at the two ends of the edge in the N double-pole pieces, and N is a positive integer greater than 1.

[0061] In this embodiment, the above-mentioned battery cell can be formed by sequentially stacking N double-pole pieces in the vertical direction, wherein the vertical direction is the direction perpendicular to the extension direction of the current collector 13, and during the stacking process, each double-pole piece can be aligned and stacked, and adjacent double-pole pieces are connected by the same electronic insulating layer. Through the arrangement of this structure, the user can change the size of N according to the actual demand, so as to control the output voltage of the battery cell, while meeting the user's demand, the energy density of the battery is improved, so as to expand the application scenarios of sodium ion battery.

[0062] It should be noted that the first pole piece 15 and the second pole piece 16 are double-pole pieces arranged on the opposite sides of the above-mentioned battery cell, and the first pole piece 15 and the second pole piece 16 are connected with the edge part 20 through the electronic insulating layer, wherein the edge part 20 can be a structure of positive electrode coating plus current collector, or a structure of negative electrode coating plus current collector. Through the arrangement of this structure, the normal working state of the battery cell is met.

[0063] It should be understood that compared with the sodium ion battery in the prior art, the battery cell provided by the embodiment of the present application reduces the setting of the diaphragm, reduces the response steps in the process flow of battery cell manufacturing, and thus improves the manufacturing efficiency.

[0064] Optionally, the electronic insulating coating 14 includes one of the following: solid electrolyte and insulating coating;

[0065] In the case where the electronic insulating coating 14 includes the solid electrolyte, the electronic insulating coating is a dense coating structure;

[0066] In the case where the electronic insulating coating 14 includes the insulating coating, the electronic insulating coating is a porous structure.

[0067] In this embodiment, the main component of the electronic insulation coating 14 can be the above-mentioned solid electrolyte or the above-mentioned insulating coating, and when the electronic insulation coating 14 is the above-mentioned solid electrolyte, the electronic insulation coating 14 can be arranged as a dense coating, and when the electronic insulation coating 14 is the above-mentioned insulating coating, the electronic insulation coating 14 can be arranged as a porous structure. In both embodiments of the electronic insulation coating 14, the energy density of the battery during operation can still be maintained.

[0068] It should be noted that when the main component of the electronic insulation coating 14 is the above-mentioned solid electrolyte, the electronic insulation coating 14 can include at least one of inorganic oxide, sulfide ceramic powder: perovskite type LLTO ceramic powder, garnet type LLZO ceramic powder, LLZTO ceramic powder, amorphous LPON ceramic powder, sulfide ceramic powder.

[0069] Similarly, the main component of the electronic insulation coating 14 can also be a high molecular material, such as at least one of high molecular nanoparticles or nanofibers, such as polyethylene nanoparticles, polyethylene nanofibers, polypropylene nanoparticles, polypropylene nanofibers.

[0070] In addition, when the electronic insulation coating 14 is a solid electrolyte, a small amount of additional liquid electrolyte can be added or not added in the above-mentioned battery, and when the electronic insulation coating 14 is a porous insulating layer, a liquid electrolyte can be injected in the above-mentioned battery according to the injection amount of 4g / Ah to 15g / Ah, so as to ensure the normal working state of the battery.

[0071] Optionally, the positive electrode coating 11 includes a sodium supplement additive; and / or

[0072] The negative electrode coating 12 includes a sodium supplement additive;

[0073] The sodium supplement additive includes at least one of sodium oxalate, sodium oxide, sodium peroxide, sodium sulfide, sodium phosphide, and a sodium-containing organic compound.

[0074] Optionally, the mass of the sodium supplement additive is m1, the mass of the positive electrode active material in the positive electrode coating is m2, and m1 and m2 satisfy the following relationship:

[0075] m1:m2 is less than or equal to 1:10;

[0076] m1:m2 is greater than or equal to 1:100.

[0077] Optionally, the positive electrode coating 11 and the negative electrode coating 12 further include a conductive agent and a binder.

[0078] The conductive agent includes one or more of carbon-based material, metal-based material, and conductive polymer. In some optional embodiments, the carbon-based material can be selected from natural graphite, artificial graphite, carbon black, acetylene black, ketjen black, carbon fiber, or any combination thereof; the metal-based material can be selected from metal powder, metal fiber, copper, nickel, aluminum, and silver; and the conductive polymer can be selected from polyphenylene derivative.

[0079] In addition, the binder includes one or more of polyvinylidene fluoride, polytetrafluoroethylene, styrene butadiene rubber, nitrile butadiene rubber, water-based acrylic resin, polyvinyl alcohol, polyvinyl butyral, polyurethane, fluorinated rubber, carboxymethyl cellulose, and polyacrylic acid.

[0080] It should be noted that the mass percentage of each substance in the active material layer in the positive electrode coating 11 and the negative electrode coating 12 can be: 75wt% to 98wt% of active material, 1wt% to 15wt% of conductive agent, and 1wt% to 10wt% of binder.

[0081] Preferably, the active material accounts for 82wt% to 96wt%, the conductive agent accounts for 2wt% to 10wt%, and the binder accounts for 2wt% to 8wt%.

[0082] Optionally, the thickness of the electronically insulating coating 14 is greater than or equal to 4 microns;

[0083] The thickness of the electronically insulating coating 14 is less than or equal to 50 microns.

[0084] As a preferred embodiment, the thickness of the electronically insulating coating 14 can be controlled to be between 10 microns and 20 microns.

[0085] Optionally, in the case where the electronically insulating coating includes the solid electrolyte, the solid electrolyte further includes a binder;

[0086] The binder includes at least one of polyvinylidene fluoride, polytetrafluoroethylene, styrene butadiene rubber, nitrile butadiene rubber, water-based acrylic resin, polyvinyl alcohol, polyvinyl butyral, polyurethane, fluorinated rubber, carboxymethyl cellulose, and polyacrylic acid.

[0087] Optionally, in the electronically insulating coating 14, the percentage content of the binder is 1.0wt% to 10.0wt%; and / or

[0088] The porosity of the solid electrolyte is 2% to 50%.

[0089] As a preferred manner, the percentage content of the binder can be controlled to be 2.0wt% to 8.0wt%; and the porosity of the solid electrolyte can be controlled to be 5% to 25%

[0090] Optionally, in the case where the electronic insulation coating 14 comprises the insulation coating, the pore size of the porous structure ranges from 0.02 microns to 0.15 microns; and / or

[0091] The porosity of the insulation coating ranges from 25% to 70%

[0092] As a preferred manner, the pore size of the porous structure can be controlled to range from 0.05 microns to 0.10 microns; and the porosity of the insulation coating can be controlled to range from 40% to 50%.

[0093] In some optional embodiments, the process for preparing the above-mentioned bipolar electrode sheet can refer to the following process:

[0094] Obtain positive electrode active material oxide material, such as: Na[Ni 1 / 3 Fe 1 / 3 Mn 1 / 3 ]O2, binder and conductive agent, and mix them according to the mass ratio of 93:3.5:3.5, then add an appropriate amount of N-methyl pyrrolidone to fully stir to form a uniform slurry, coat the slurry on the first side of the current collector, then dry, roll to a density of 2.0 g / cm 3 for standby.

[0095] Obtain hard carbon, conductive agent, binder and thickening agent according to the mass ratio of 94:1.0:2.5:2.0, wherein the conductive agent can be carbon black, the binder can be styrene-butadiene rubber, and the thickening agent can be sodium carboxymethyl cellulose, then mix the powders uniformly, add an appropriate amount of deionized water, fully stir to form a uniform slurry, coat the slurry on the second side of the current collector, then dry, roll to obtain a bipolar electrode sheet.

[0096] In some optional embodiments, the process for preparing the above-mentioned electronic insulation coating can refer to the following process:

[0097] Obtain garnet-type LLZO ceramic powder, sodium supplement additive and binder, and mix them according to the mass ratio of 90:7:3, then add an appropriate amount of N-methyl pyrrolidone, fully stir to form a uniform slurry, then coat the slurry on the positive electrode surface or the negative electrode surface of the bipolar current collector, then dry, roll and slice to obtain an electronic insulation coating bipolar electrode sheet.

[0098] Wherein the sodium supplement additive can be sodium oxalate, and the binder can be polyvinylidene fluoride.

[0099] In some optional embodiments, the process for preparing the electrolyte can refer to the following process:

[0100] In an argon-filled glove box with water content <1 ppm, ethylene carbonate, propylene carbonate and diethyl carbonate were mixed in a mass ratio of 0.5:1.5:1.5, and 1.0 mol / L sodium hexafluorophosphate (NaPF6) was added, and stirred uniformly to obtain a sodium metal battery electrolyte.

[0101] The electrolyte includes an organic solvent and a sodium salt, and the organic solvent can include one or more of propylene carbonate, an ether compound, ethylene carbonate, butylene carbonate, difluoroethylene carbonate, fluorodimethyl carbonate, fluoromethyl ethyl carbonate, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methyl ethyl carbonate, methyl formate, ethyl formate, propyl formate, butyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, butyl butyrate, methyl difluoroacetate, ethyl difluoroacetate, γ-butyrolactone, γ-valerolactone, δ-valerolactone, sulfolane, dimethyl sulfoxide, dichloromethane and dichloroethane.

[0102] The sodium salt can include one or more of sodium hexafluorophosphate (NaPF6), sodium tetrafluoroborate (NaBF4), sodium perchlorate (NaClO4), sodium hexafluoroarsenate (NaAsF6), sodium hexafluoroantimonate (NaSbF6), sodium difluorophosphate (NaPF2O2), sodium 4,5-dicyano-2-trifluoromethylimidazole (NaDTI), sodium bis(oxalato)borate (NaBOB), sodium bis(malonato)borate (NaBMB), sodium difluoro(oxalato)borate (NaDFOB), sodium bis(difluoromalonato)borate (NaBDFMB), sodium (malonato)(oxalato)borate (NaMOB), sodium (difluoromalonato)(oxalato)borate (NaDFMOB), sodium tris(oxalato)phosphate (NaTOP), sodium tris(difluoromalonato)phosphate (NaTDFMP), sodium tetrafluoro(oxalato)phosphate (NaTFOP), sodium difluoro(di-oxalato)phosphate (NaDFOP), sodium bis(fluorosulfonyl)imide (NaFSI), sodium bis(trifluoromethanesulfonyl)imide (NaTFSI), sodium (fluorosulfonyl)(trifluoromethanesulfonyl)imide (NaN(SO2F)(SO2CF3)), sodium nitrate (NaNO3) and sodium fluoride (NaF).

[0103] It should be noted that the concentration of the sodium salt in the electrolyte can be controlled at 0.2 mol / L to 5.0 mol / L, for example: 0.2 mol / L, 0.5 mol / L, 0.8 mol / L, 1 mol / L, 1.2 mol / L, 1.5 mol / L, 1.8 mol / L, 2.0 mol / L, 3.0 mol / L, 4.0 mol / L or 5.0 mol / L, which is not limited by the embodiments of the present application.

[0104] Optionally, the electrolyte further comprises an additive, which comprises one or more of the following: vinylene carbonate, vinyl ethylene carbonate, 1,3-propane sultone, trifluoromethyl vinyl carbonate, dimethyl sulfate, vinyl sulfate, vinyl methyl sulfate, propylene sulfate, vinyl sulfite, succinic anhydride, biphenyl, diphenyl ether, toluene, xylene, cyclohexylbenzene, fluorobenzene, p-fluorotoluene, p-fluorotoluene methyl ether, t-butylbenzene, t-amylbenzene, propene sultone, butane sultone, methanedi(methyl sulfonate), ethylene glycol bis(propionitrile) ether, hexamethyldisilazane, heptamethyldisilazane, dimethyl methylphosphonate, diethyl ethylphosphonate, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, triphenyl phosphite, tris(trimethylsilyl) borate, and tris(trimethylsilyl) phosphate.

[0105] It should be noted that the content of the additive is 0.01% to 10% of the total mass of the electrolyte, preferably, the content of the additive is 1.0% to 5.0% of the total mass of the electrolyte.

[0106] The embodiments of the present application also provide a battery comprising the above-mentioned battery cell.

[0107] In some optional embodiments, the manufacturing process of the above-mentioned battery is as follows:

[0108] The bipolar electrode coated with the electronic insulation coating is stacked in the same direction, for example, the electronic insulation coating is coated on the positive electrode side, and the coating faces upward, and then stacked in sequence; the electronic insulation coating is coated on the positive electrode side, and the coating faces downward, and then stacked in sequence. Of course, the electronic insulation coating can also be arranged on the negative electrode side.

[0109] Then, the stacked battery cell is placed in an aluminum-plastic film packaging bag, a small amount of electrolyte (1.0 g / Ah) is injected, and vacuum sealing, standing, formation, shaping and other processes are performed, so that the above-mentioned battery can be prepared.

[0110] In addition, after the above-mentioned battery is prepared, the performance of the electronic insulation coating bipolar electrode sodium ion battery can be tested, and the following two tests can be performed:

[0111] (1) Test of first circle discharge capacity and first circle coulombic efficiency: the mixed lithium-sodium ion battery is placed at 25°C, and charged at 0.2C constant current to the upper limit voltage (4.0V), and then charged at 4.0V constant voltage to the current of 0.05C, and then discharged at 0.2C constant current to the voltage of 2.0V, and the discharge capacity is recorded as the first circle discharge capacity, wherein the first circle coulombic efficiency is the ratio of the first circle discharge specific capacity to the charge specific capacity.

[0112] (2) Test of room temperature cycle life: the mixed lithium-sodium ion battery is placed at 25°C, charged at 0.5C constant current to the upper limit voltage (4.0V), then charged at 4.0V constant voltage to the current of 0.05C, and rested for 5 minutes; then discharged at 0.5C constant current to the voltage of 2.0V, and rested for 5 minutes, which is one charge-discharge cycle. Such charging / discharging, the ratio of the discharge capacity after 100 cycles to the first cycle discharge capacity is recorded, that is, the capacity retention rate of 100 cycles.

[0113] Table 1

[0114]

[0115] Referring to Table 1, Table 1 shows the information of the electronic insulation coating in different examples and comparative examples and the amount of liquid injection.

[0116] Table 2

[0117]

[0118]

[0119] Referring to Table 2, Table 2 shows the test of the electrochemical performance of different examples and comparative examples.

[0120] The following conclusions can be drawn by comparing Comparative Example 1, Example 2 and Comparative Example 2: within a certain thickness range, the smaller the thickness of the solid-state electrolyte coating, the more conducive to the performance of the battery.

[0121] The following conclusions can be drawn by comparing Example 2 and Example 3: under the same electrolyte coating conditions, the more liquid electrolyte added, the more conducive to the cycle stability of the battery.

[0122] The following conclusions can be drawn by comparing Comparative Example 9 and Example 10: the porous insulation layer does not have the ability to conduct ions, so the amount of liquid electrolyte required is larger, which can ensure the performance of the battery.

[0123] The following conclusions can be drawn by comparing Example 3 and Example 7: the effect of the electronic insulation coating coated on the positive electrode surface and the negative electrode surface is similar, so the position of the electronic insulation coating can be determined according to the actual working conditions.

[0124] In addition, the above-described battery can be applied to electronic devices, which can be mobile computers, notebook computers, portable telephones, electronic book players, portable facsimile machines, portable copying machines, portable printers, head-mounted stereo headphones, video recorders, liquid crystal televisions, hand-held cleaners, calculators, memory cards, portable audio recorders, radio receivers, backup power supplies, automobiles, motorcycles, electric ships, bicycles, lighting fixtures, toys, game machines, timepieces, power tools, cameras, household large-size storage batteries, and energy storage power stations, and the like, and the present application is not limited to the above.

[0125] It should be noted that the terms "comprising", "including", or any other variant thereof, are intended to cover a non-exclusive inclusion, such that processes, methods, articles, or apparatuses that comprise a list of elements are not limited to those elements, but can also include other elements not expressly listed, or can also include elements inherent in such processes, methods, articles, or apparatuses. Without further limitation, an element defined by the phrase "comprising a" does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element. In addition, it should be noted that the scope of the methods and apparatuses in the present embodiments is not limited to performing functions in the order discussed, but can also include performing functions in a substantially simultaneous manner or in reverse order, for example, the described methods can be performed in an order different from that described, and various steps can be added, omitted, or combined. In addition, features described with reference to certain examples can be combined in other examples.

[0126] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-described specific embodiments, and the above-described specific embodiments are merely illustrative, rather than limiting, and a person of ordinary skill in the art can make many forms under the inspiration of the present application without departing from the purpose of the present application and the scope protected by the claims, and all of them belong to the protection of the present application.

Claims

1. A battery, characterized by, The dual-pole sheet comprises a positive electrode coating, a negative electrode coating, a current collector, and an electron-insulating coating; The positive electrode coating and the negative electrode coating are respectively arranged on opposite surfaces of the current collector; The electron-insulating coating is arranged on the surface of at least one of the positive electrode coating and the negative electrode coating; The positive electrode coating and / or the negative electrode coating contains a sodium supplementing additive; The electron-insulating coating comprises a solid electrolyte; In the case where the electron-insulating coating comprises the solid electrolyte, the electron-insulating coating is a dense coating structure; The battery further comprises a liquid electrolyte, and the content of the liquid electrolyte is 1-2 g / Ah.

2. The battery of claim 1, wherein, The battery comprises N dual-pole sheets, and the N dual-pole sheets are sequentially stacked in a vertical direction, wherein the vertical direction is perpendicular to the direction in which the current collector extends; In the N dual-pole sheets, adjacent dual-pole sheets are connected by the same electron-insulating layer. In the N dual-pole sheets, a first pole sheet and a second pole sheet are connected to an edge portion by an electron-insulating layer, and the edge portion comprises one of the following: a positive electrode coating plus a current collector, and a negative electrode coating plus a current collector. The first pole sheet and the second pole sheet are dual-pole sheets located at the two ends of the edge, N is a positive integer greater than 1.

3. The battery of claim 1, wherein, The sodium supplementing additive comprises at least one of the following: sodium oxalate, sodium oxide, sodium peroxide, sodium sulfide, sodium phosphide, and a sodium-containing organic compound.

4. The battery of claim 3, wherein, The mass of the sodium supplementing additive is m1, the mass of the positive electrode active material in the positive electrode coating is m2, and m1 and m2 satisfy the following relationships: m1:m2 is less than or equal to 1:10; m1:m2 is greater than or equal to 1:

100.

5. The battery of claim 1, wherein, The thickness of the electron-insulating coating is greater than or equal to 4 microns; and / or The thickness of the electron-insulating coating is less than or equal to 50 microns.

6. The battery of claim 1, wherein, In the case where the electron-insulating coating comprises the solid electrolyte, the solid electrolyte further comprises a binder; The binder comprises at least one of the following: polyvinylidene fluoride, polytetrafluoroethylene, butadiene styrene rubber, butyl nitrile rubber, water-based acrylic resin, polyvinyl alcohol, polyvinyl butyral, polyurethane, fluorinated rubber, carboxymethyl cellulose, and polyacrylic acid.

7. The battery of claim 6, wherein, In the electron-insulating coating, the percentage content of the binder is 1.0 wt% to 10.0 wt%; and / or The porosity of the solid electrolyte is 2% to 50%.

8. The battery of claim 1, wherein, In the case where the electron-insulating coating comprises an insulating coating, the pore size of the porous structure ranges from 0.02 microns to 0.15 microns.

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