A high-temperature resistant and long-life lithium-ion or sodium-ion battery and its preparation method

Abstract

The present invention relates to a high-temperature resistant and long-life lithium-ion battery or sodium-ion battery and a preparation method thereof. The lithium-ion battery or sodium-ion battery includes a positive electrode, a negative electrode, a separator and an electrolyte. The positive electrode includes a current collector and a positive electrode coating material loaded on the current collector. The positive electrode coating material includes a positive electrode active material containing a transition metal and a polymer containing a coordination group. The coordination group can coordinate with the transition metal ions in the positive electrode active material, and at 25-60 °C, the swelling degree of the polymer containing the coordination group in the electrolyte is 5-50%. In the present invention, a polymer containing a coordination group is added to the positive electrode material. Through the coordination of the coordination group with the transition metal ions, the polymer can be firmly adsorbed on the surface of the active material to form a stable protective layer, inhibiting the oxidation of the electrolyte and the dissolution of the transition metal ions, thereby greatly improving the high-temperature performance and safety of the battery.

Description

Technical Field

[0001] The present invention relates to the fields of lithium-ion batteries and sodium-ion batteries, and particularly to a high-temperature resistant and long-life lithium-ion battery or sodium-ion battery and a preparation method thereof. Background Art

[0002] Lithium batteries have been widely used in portable electronic devices such as mobile phones, tablet computers, and laptop computers, new energy vehicles, energy storage, etc. due to their high energy density. Sodium batteries have also attracted much attention due to their low cost, relatively high energy density, and good high and low temperature performance. High energy density lithium-ion batteries usually use transition metal oxide-based cathode active materials such as lithium cobalt oxide, lithium manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and lithium iron phosphate. Sodium-ion batteries also usually use transition metal oxide-based cathode active materials such as sodium nickel oxide, sodium cobalt oxide, sodium manganese oxide, sodium nickel iron manganese, and sodium copper iron manganese, because they have a relatively high working potential and a relatively high specific capacity. However, the transition metal ions on the surface of these transition metal oxide-based cathode active materials have certain instability, which may lead to the oxidation decomposition of the electrolyte, and at the same time, they may be corroded and dissolved into the electrolyte by trace hydrogen fluoride in the electrolyte. These two situations will both lead to the deterioration of the battery performance. Specifically, on the one hand, the oxidation decomposition of the electrolyte will consume the electrolyte, resulting in a reduction in the cycle life. On the other hand, it will also generate gas, causing the battery to bulge and posing a safety hazard. And the dissolution of transition metal ions into the electrolyte will migrate to the negative electrode and be reduced, damaging the negative electrode SEI, thereby causing the attenuation of the cycle performance. Even the reduced transition metal may form dendrites and pierce the separator, resulting in a short circuit and posing a serious safety hazard. This performance deterioration and safety risk caused by the oxidation decomposition of the electrolyte and the dissolution of transition metal ions are particularly prominent at high temperatures or at a charging cut-off voltage of 4.3V or above.

[0003] Therefore, certain specific additives such as 1,3-propane sultone or 1,3-propene sultone are usually added to the electrolytes of lithium-ion batteries or sodium-ion batteries. They can decompose on the surface of the cathode active material to form a certain protective layer, inhibiting the decomposition of the electrolyte and the dissolution of transition metal ions. However, this method has a drawback. We cannot make such additives act only on the cathode. They will be reduced to form SEI on the negative electrode at the same time. And usually, the negative electrode SEI formed by such additives has a problem of high impedance, which will lead to the deterioration of the charging performance of lithium-ion batteries or sodium-ion batteries, and even cause lithium / sodium dendrites to form on the surface of the negative electrode during charging, posing a serious safety hazard. Summary of the Invention

[0004] Problems to be solved by the present invention: In a lithium-ion battery or a sodium-ion battery using a transition metal oxide-based positive electrode active material, there are problems of oxidative decomposition of the electrolyte on the surface of the positive electrode active material and dissolution of transition metal ions into the electrolyte, which can lead to deterioration of battery performance and may pose safety hazards. Such performance deterioration and safety risks caused by oxidative decomposition of the electrolyte and dissolution of transition metal ions are particularly prominent at high temperatures or at a charging cut-off voltage of 4.3 V or above.

[0005] In view of the above problems, the object of the present invention is to provide a lithium-ion battery or a sodium-ion battery and a method for preparing the same.

[0006] To solve the above problems, the technical solution of the present invention is as follows:

[0007] In a first aspect, the present application provides a lithium-ion battery or a sodium-ion battery, which includes a positive electrode, a negative electrode, a separator, and an electrolyte. The positive electrode includes a current collector and a positive electrode coating material loaded on the current collector. The positive electrode coating material includes a positive electrode active material containing a transition metal and a polymer containing a coordination group. The coordination group can coordinate with the transition metal ions in the positive electrode active material, and at 25-60 °C, the swelling degree of the polymer containing the coordination group in the electrolyte is 5-50%.

[0008] In some embodiments of the present application, the coordination group contains one or more of cyano, carbonyl, pyridyl, pyrazinyl, pyrimidinyl, furyl, pyrrolyl, thienyl, thiazolyl, and oxazolyl.

[0009] In some embodiments of the present application, the coordination group contains two or more atoms capable of coordinating with the same transition metal ion.

[0010] In some embodiments of the present application, the coordination group includes one or more of the following structures:

[0011]

[0012] Among them, R1 is selected from one of hydrogen, hydrocarbon group, halogenated hydrocarbon group, oxygen-containing substituted hydrocarbon group, nitrogen-containing substituted hydrocarbon group, phosphorus-containing substituted hydrocarbon group, or sulfur-containing substituted hydrocarbon group. R2 and R4 are each independently selected from one of hydrocarbon group, halogenated hydrocarbon group, oxygen-containing substituted hydrocarbon group, nitrogen-containing substituted hydrocarbon group, phosphorus-containing substituted hydrocarbon group, or sulfur-containing substituted hydrocarbon group. R3 is selected from one of hydrogen, hydrocarbon group, halogenated hydrocarbon group, oxygen-containing substituted hydrocarbon group, nitrogen-containing substituted hydrocarbon group, phosphorus-containing substituted hydrocarbon group, or sulfur-containing substituted hydrocarbon group. X1 is selected from S, NH, or O, and X2 is selected from S or O.

[0013] In some embodiments of the present application, the polymer containing a coordination group is selected from one or more of polyolefins, polyesters, polyamides, polyurethanes, and polyimides.

[0014] In some embodiments of the present application, based on the total weight of the solid matter of the positive electrode coating material loaded on the current collector, the content of the polymer containing a coordination group is 0.1-10%, preferably 0.2-5%, more preferably 0.2-2%, and further preferably 0.5-2%.

[0015] In some embodiments of the present application, the transition metal is selected from one or more of nickel, cobalt, manganese, copper, and iron.

[0016] In some embodiments of the present application, the electrolyte includes an organic solvent; preferably, the organic solvent is selected from one or more of ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, and propyl propionate;

[0017] Preferably, in the lithium battery, the electrolyte further includes a lithium salt, and the lithium salt is selected from one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis(trifluoromethylsulfonyl)imide, and lithium bis(fluorosulfonyl)imide, or,

[0018] In the sodium battery, the electrolyte further includes a sodium salt, and the sodium salt is selected from one or more of sodium hexafluorophosphate, sodium tetrafluoroborate, sodium bis(trifluoromethylsulfonyl)imide, and sodium bis(fluorosulfonyl)imide.

[0019] In some embodiments of the present application, the electrolyte further includes one or more of an unsaturated cyclic carbonate, a fluorinated cyclic carbonate, a cyclic sultone, and a cyclic sulfate;

[0020] Preferably, the unsaturated cyclic carbonate is selected from vinylene carbonate and / or ethylene vinyl carbonate, and / or the fluorinated cyclic carbonate is selected from at least one of fluorinated ethylene carbonate, trifluoromethyl ethylene carbonate, or difluorinated ethylene carbonate, and / or the cyclic sultone is selected from at least one of 1,3-propane sultone, 1,4-butane sultone, and allyl-1,3-sultone, and / or the cyclic sulfate is selected from at least one of ethylene sulfate, propylene sulfate, and 4-methyl ethylene sulfate.

[0021] In a second aspect, the present application further provides a method for preparing the above-mentioned lithium-ion battery or sodium-ion battery. The preparation method includes placing a positive electrode, a negative electrode, and a separator to form an electrode core in a battery case, and then injecting an electrolyte to obtain a semi-finished lithium-ion battery or a semi-finished sodium-ion battery. The semi-finished lithium-ion battery or the semi-finished sodium-ion battery is formed and exhausted, and then the liquid injection port of the battery case is sealed to obtain a lithium-ion battery or a sodium-ion battery.

[0022] Among them, the positive electrode is obtained by coating a positive electrode coating material on a current collector and then drying, rolling, and slitting. The positive electrode coating material is prepared by mixing the polymer containing a coordination group with a solvent and then mixing with a positive electrode active material, a conductive agent, and a binder.

[0023] In a third aspect, the present application further provides a positive electrode coating material, which includes a positive electrode active material containing a transition metal and a polymer containing a coordination group; preferably, the positive electrode coating material further contains a conductive agent and a binder.

[0024] In a fourth aspect, the present application further provides a method for preparing the above-mentioned positive electrode coating material, which includes mixing the polymer containing a coordination group with a solvent and then mixing with a positive electrode active material, a conductive agent, and a binder.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention adds a polymer containing a coordination group to the positive electrode material. The coordination group in the polymer can coordinate with the transition metal ions on the surface of the positive electrode active material, so that the polymer containing a coordination group can be firmly adsorbed on the surface of the active material to form a stable protective layer, inhibiting the oxidation of the electrolyte and the dissolution of transition metal ions, thereby greatly improving the high-temperature performance of the lithium-ion battery or sodium-ion battery and improving the safety of the lithium-ion battery or sodium-ion battery; at the same time, the polymer containing a coordination group has a low swelling degree in the electrolyte (the swelling degree is less than 50%), so that the protective layer formed by the polymer containing a coordination group can well inhibit the oxidation decomposition of the electrolyte on the surface of the positive electrode active material and the dissolution of transition metal ions, improving the service life and safety of the battery. And the polymer containing a coordination group has a certain ionic conductivity after swelling in the electrolyte, allowing lithium ions or sodium ions to pass through the protective layer and embed into the positive electrode active material or enter the electrolyte through the protective layer after being released from the positive electrode active material. Specific Embodiments

[0027] To make the objectives, technical solutions, and technical effects of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely. The embodiments described below are some, but not all, of the embodiments of this application. All other embodiments obtained by those of ordinary skill in the art in connection with the embodiments of this application without creative efforts shall fall within the scope of protection of this invention.

[0028] To better understand the above technical solutions, the following provides a more detailed description of this application.

[0029] In a first aspect, in a specific implementation of this application, the present invention provides a lithium-ion battery or a sodium-ion battery, including a positive electrode, a negative electrode, a separator, and an electrolyte. Among them, the positive electrode includes a current collector and a positive electrode coating material loaded on the current collector. The positive electrode coating material includes a positive electrode active material containing a transition metal and a polymer containing a coordination group. The coordination group can coordinate with the transition metal ions in the positive electrode active material, and at 25-60 °C, the swelling degree of the polymer containing the coordination group in the electrolyte is 5-50%. The reason for controlling the swelling degree within the above range is that when the swelling degree is too low, the ionic conductivity of the polymer layer is too low, resulting in a large internal resistance of the battery. When the swelling degree is too high, the polymer layer cannot effectively inhibit the side reaction between the electrolyte and the surface of the active material, and cannot achieve the effect of significantly improving the high-temperature performance and safety.

[0030] In some embodiments of this application, the coordination group includes one or more of cyano, carbonyl, pyridyl, pyrazinyl, pyrimidinyl, furyl, pyrrolyl, thienyl, thiazolyl, and oxazolyl.

[0031] In some embodiments of this application, the coordination group includes two or more atoms that can coordinate with the same transition metal ion.

[0032] In some embodiments of this application, the coordination group is composed of two or three adjacent functional groups selected from cyano, carbonyl, pyridyl, pyrazinyl, pyrimidinyl, furyl, pyrrolyl, thienyl, thiazolyl, and oxazolyl, and the functional groups are in a suitable spatial arrangement so that the oxygen atoms and / or nitrogen atoms on these functional groups can coordinate with the same transition metal ion. Examples of the coordination group include any of the following structures: a structure with a cyano group and / or a carbonyl group on or adjacent to the ring of pyridine, bipyridine, pyrimidine, pyrazine, or furan, a structure containing two adjacent cyano groups, a structure containing adjacent cyano and carbonyl groups, and a structure containing two adjacent carbonyl groups.

[0033] It should be noted that the proximity mentioned herein refers to the position where the oxygen atom or nitrogen atom on the functional group can coordinate with the same transition metal ion, which can be adjacent or non - adjacent.

[0034] In some embodiments of the present application, the coordination group includes one or more of the following structures:

[0035]

[0036] Wherein, R1 is selected from one of hydrogen, hydrocarbon group, halogenated hydrocarbon group, oxygen - containing substituted hydrocarbon group, nitrogen - containing substituted hydrocarbon group, phosphorus - containing substituted hydrocarbon group or sulfur - containing substituted hydrocarbon group; R2 and R4 are each independently selected from one of hydrocarbon group, halogenated hydrocarbon group, oxygen - containing substituted hydrocarbon group, nitrogen - containing substituted hydrocarbon group, phosphorus - containing substituted hydrocarbon group or sulfur - containing substituted hydrocarbon group; R3 is selected from one of hydrogen, hydrocarbon group, halogenated hydrocarbon group, oxygen - containing substituted hydrocarbon group, nitrogen - containing substituted hydrocarbon group, phosphorus - containing substituted hydrocarbon group or sulfur - containing substituted hydrocarbon group; X1 is selected from S, NH or O; X2 is selected from S or O.

[0037] It should be noted that in the molecular formulas described herein, the wavy line represents the connection to the polymer chain. R1 is a substituent group on the aromatic ring. When R1 is hydrogen, it means that this position is not substituted by a substituent.

[0038] The advantage of using the above - mentioned coordination group is that this coordination group is a polydentate ligand, which can form a more stable coordination with the transition metal ion (as shown in formula 24), enabling the polymer containing the coordination group to adsorb more stably on the surface of the cathode active material particles, facilitating the formation of a more complete and stable protective layer, and thus more effectively inhibiting the decomposition reaction of the electrolyte on the surface of the cathode active material.

[0039]

[0040] Wherein, R1 is selected from one of hydrogen, hydrocarbon group, halogenated hydrocarbon group, oxygen - containing substituted hydrocarbon group, nitrogen - containing substituted hydrocarbon group, phosphorus - containing substituted hydrocarbon group or sulfur - containing substituted hydrocarbon group, and M n+ is a transition metal ion.

[0041] In some embodiments of the present application, the polymer containing the coordination group is selected from one or more of polyolefin, polyester, polyamide, polyurethane and polyimide.

[0042] In the present application, polyolefin, polyester, polyamide, polyurethane and polyimide are classified according to the different main - chain structures.

[0043] Among them, the synthesis route of polyolefins can be: obtained by free radical polymerization of monomers containing carbon-carbon double bonds under the action of an initiator. Common monomers containing carbon-carbon double bonds include acrylonitrile, acrylate, methacrylate, cyanoacrylate, N-vinylpyrrolidone, vinylpyridine, N,N-dimethylacrylamide, etc.

[0044] The synthesis routes of polyesters are divided into two categories. One category has a main chain obtained by ring-opening polymerization of lactone monomers initiated by polyols or polycarboxylic acids or initiators containing hydroxycarboxylic acids. Its synthesis route is respectively to obtain polyester polyols or polyester polyacids or polyesters containing multiple hydroxyl groups and carboxylic acids by ring-opening polymerization of lactone monomers initiated by compounds of polyols or polycarboxylic acids or initiators containing hydroxycarboxylic acids. Representative polyols include ethylene glycol, glycerol, trimethylolpropane, pentaerythritol, inositol, etc. Representative polycarboxylic acids include succinic acid, malonic acid, trimellitic acid, butanetetracarboxylic acid, pyromellitic acid, etc. Representative initiators containing hydroxycarboxylic acids include glycolic acid, malic acid, citric acid, tartaric acid, etc. Representative lactone monomers include glycolide, lactide, δ-valerolactone, ε-caprolactone, etc. Another category has a main chain obtained by polycondensation of diacid monomers and diol monomers. Its synthesis route is to obtain polyester polyols by polycondensation of diacid monomers and diol monomers. Representative diacids include succinic acid, adipic acid, terephthalic acid, etc. Representative diols include ethylene glycol, 1,3-propanediol, 1,6-hexanediol, etc.

[0045] The synthesis routes of polyamides are divided into two categories. One category has a main chain obtained by ring-opening polymerization of caprolactam monomers initiated by alkali metals or water to obtain polyamides with amine groups and carboxylate groups at both ends. Representative alkali metal initiators include sodium hydroxide, sodium methoxide, etc. Another category has a main chain obtained by polycondensation of diacid monomers and diamine monomers. Its synthesis route is to obtain polyamides by polycondensation of diacid monomers and diamine monomers. Representative diacids include succinic acid, adipic acid, terephthalic acid, etc. Representative diamines include ethylenediamine, hexamethylenediamine, polyetheramine, p-phenylenediamine, etc.

[0046] The synthesis route of polyimides can be to first react a dianhydride and a diamine to form a polyamic acid, and then carry out an imidization reaction at high temperature. Representative dianhydrides include 4,4'-biphenylether dianhydride, bisphenol A type diether dianhydride, 4,4'-carbonyl diophthalic anhydride, etc. Representative diamines include 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, polyetheramine, etc.

[0047] The synthesis route of polyurethanes can be polyurethanes formed by the reaction of diols and diisocyanates. Representative diols include polyethylene glycol, hydroxy-terminated polycaprolactone, hydroxy-terminated polyester oligomers obtained by polycondensation of diols and diacids, etc. Representative diisocyanates include hexamethylene diisocyanate, toluene diisocyanate, etc.

[0048] In some embodiments of the present application, the polymer containing a coordination group includes, but is not limited to, one or more of Polyolefin 1, Polyolefin 2, Polyolefin 3, Polyolefin 4, Polyolefin 5, Polyolefin 6, Polyolefin 7, Polyolefin 8, Polyolefin 9, Polyolefin 10, Polyolefin 11, Polyolefin 12, Polyolefin 13, Polyolefin 14, Polyolefin 15, Polyolefin 16, Polyolefin 17, Polyolefin 18, Polyolefin 19, Polyolefin 20, Polyolefin 21, Polyolefin 23, Polyester 1, Polyester 2, Polyester 3, Polyester 4, Polyester 5, Polyester 6, Polyester 7, Polyamide 1, Polyamide 2, Polyamide 3, Polyamide 4, Polyamide 5, Polyurethane 1, and Polyimide 1. Preferably, it is one or more of Polyolefin 1, Polyolefin 2, Polyolefin 3, Polyolefin 10, Polyolefin 11, Polyolefin 13, Polyester 1, Polyester 2, Polyester 3, Polyester 6, Polyester 7, Polyamide 1, Polyamide 2, Polyurethane 1, and Polyimide 1. Details of each of the above polymers can be found in the description of the examples.

[0049] In some embodiments of the present application, based on the total weight of the solid matter of the positive electrode coating material loaded on the current collector, the content of the polymer containing a coordination group is 0.1 - 10%, preferably 0.2 - 5%, more preferably 0.2 - 2%, and further preferably 0.5 - 2%. The reason for selecting the above preferred range for the polymer addition amount is as follows: When the content of the polymer is too low, the polymer cannot effectively cover the surface of the active material, and the improvement effect on high-temperature performance and safety is not obvious; when the content of the polymer is too high, on the one hand, it affects ion transport, increases the internal resistance of the battery, and on the other hand, it reduces the energy density of the battery.

[0050] In some embodiments of the present application, at 25 - 60 °C, the swelling degree of the polymer containing a coordination group in the electrolyte is 5 - 45%, and preferably the swelling loss rate < 2%. When the swelling degree of the polymer containing a coordination group is controlled within the scope of the present invention, the protective layer formed by the polymer containing a coordination group can well inhibit the oxidative decomposition of the electrolyte and the dissolution of transition metal ions. At the same time, the polymer containing a coordination group has a certain ionic conductivity after swelling in the electrolyte, allowing lithium ions or sodium ions to embed into the positive electrode active material through the protective layer or enter the electrolyte through the protective layer after being released from the positive electrode active material.

[0051] It should be noted that the swelling degree described in the present invention refers to the ratio of the mass difference of the polymer containing coordination groups before and after soaking in the electrolyte to the mass of the polymer before soaking. The specific test method is as follows: Prepare a circular thin film with a thickness of 30 μm and a size of 16 mm * 16 mm from the polymer containing coordination groups, weigh the mass of the thin film, soak the thin film in 10 g of electrolyte, seal it, and store it at a certain temperature (for example, 60 °C). Take out the thin film every 8 h, wipe off the electrolyte on the surface, measure the thickness and weigh it, then put it back into the electrolyte, seal it, and continue to store it at a certain temperature (for example, 60 °C) until the thickness and mass of the thin film remain unchanged for three consecutive tests, then it is considered that the polymer sheet containing coordination groups reaches the swelling equilibrium state. Calculate the swelling degree according to the following formula:

[0052]

[0053] In the above formula, m0 represents the mass of the polymer thin film containing coordination groups before soaking in the electrolyte, and m1 represents the mass of the polymer thin film containing coordination groups after reaching the swelling equilibrium after soaking in the electrolyte.

[0054] The swelling loss rate described in this application refers to the ratio of the mass loss caused by the dissolution of part of the polymer into the electrolyte during the swelling of the polymer containing coordination groups in the electrolyte to the mass of the polymer before swelling. The specific test method is as follows: Prepare a circular thin film with a thickness of 30 μm and a size of 16 mm * 16 mm from the polymer containing coordination groups, weigh the mass of the thin film, soak the thin film in 10 g of electrolyte, seal it, and store it at a certain temperature (for example, 60 °C). Take out the thin film every 8 h, wipe off the electrolyte on the surface, measure the thickness and weigh it, then put it back into the electrolyte, seal it, and continue to store it at a certain temperature (for example, 60 °C) until the thickness and mass of the thin film remain unchanged for three consecutive tests. Rinse off the excess electrolyte and lithium salt on the thin film with the solvent dimethyl carbonate (DMC), dry it completely in an oven, weigh the mass of the remaining thin film after drying, and calculate the swelling loss rate according to the following formula:

[0055]

[0056] In the above formula, m0 represents the mass of the polymer thin film containing coordination groups before soaking in the electrolyte, with the unit of g, and m2 represents the mass of the remaining polymer thin film containing coordination groups after washing and drying after soaking in the electrolyte, with the unit of g.

[0057] In some embodiments of the present application, the electrolyte includes an organic solvent. Preferably, the non-aqueous organic solvent is selected from one or more of ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, and propyl propionate.

[0058] In some embodiments of the present application, in the lithium battery, the electrolyte further includes a lithium salt, and the lithium salt is selected from one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis(trifluoromethylsulfonyl)imide, and lithium bis(fluorosulfonyl)imide, or

[0059] in the sodium battery, the electrolyte further includes a sodium salt, and the sodium salt is selected from one or more of sodium hexafluorophosphate, sodium tetrafluoroborate, sodium bis(trifluoromethylsulfonyl)imide, and sodium bis(fluorosulfonyl)imide.

[0060] In some embodiments of the present application, the electrolyte further includes one or more of an unsaturated cyclic carbonate, a fluorinated cyclic carbonate, a cyclic sultone, and a cyclic sulfate; preferably, the unsaturated cyclic carbonate is selected from vinylene carbonate and / or ethylene vinyl carbonate, and / or the fluorinated cyclic carbonate is selected from at least one of fluorinated ethylene carbonate, trifluoromethyl ethylene carbonate, or difluorinated ethylene carbonate, and / or the cyclic sultone is selected from at least one of 1,3-propane sultone, 1,4-butane sultone, and allyl-1,3-sultone, and / or the cyclic sulfate is selected from at least one of ethylene sulfate, propylene sulfate, and 4-methyl ethylene sulfate.

[0061] In some embodiments of the present application, the positive electrode includes a current collector and a positive electrode coating material loaded on the current collector. The current collector can be various current collectors well-known to those skilled in the art, such as aluminum foil, carbon-coated aluminum foil, and aluminized polymer film; the positive electrode coating material includes a positive electrode active material containing a transition metal and the above polymer containing a coordination group.

[0062] In the present application, the transition metal in the positive electrode active material is selected from one or more of nickel, cobalt, manganese, copper, and iron.

[0063] It can be understood that the above positive electrode coating material further includes a positive electrode conductive agent and a binder; the above positive electrode active material includes, but is not limited to, lithium nickel cobalt manganese oxide (LiNi x Co y Mn 1-x-y O2, where x≥0, y≥0, and x + y≤1.0), lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), lithium manganese oxide (LiMn2O4), sodium nickel iron manganese oxide (NaNi x Fe y Mn 1-x-y O2, where x≥0, y≥0, and x + y≤1.0), sodium copper iron manganese oxide (Na 0.9 Cu x Fe y Mn 1-x-yO2, where x ≥ 0, y ≥ 0, and x + y ≤ 1.0); the positive electrode conductive agent includes, but is not limited to, one or more of carbon black, carbon nanotubes (CNT), flake graphite, Ketjen black, and VGCF; the binder includes, but is not limited to, one or more of polyvinylidene fluoride (PVDF), copolymers of vinylidene fluoride (VF2), and polyimide.

[0064] In some embodiments of the present application, the negative electrode includes a current collector and a negative electrode coating material coated on the current collector. The current collector can be various current collectors well-known to those skilled in the art, such as copper foil, carbon-coated copper foil, and copper-plated polymer film; the negative electrode coating material includes a negative electrode active material.

[0065] It can be understood that the above negative electrode coating material further includes a negative electrode conductive agent and a binder; the above negative electrode active material includes, but is not limited to, artificial graphite (C), silicon carbide, silicon oxide, or mesocarbon microbeads; the conductive agent includes, but is not limited to, one or more of carbon black, carbon nanotubes (CNT), flake graphite, Ketjen black, and VGCF; the binder includes, but is not limited to, one or more of styrene-butadiene rubber latex (SBR), sodium carboxymethyl cellulose (CMC), and polyacrylic acid polymers (PAA).

[0066] In some embodiments of the present application, the separator includes a polymer porous membrane and a separator coating material coated on the polymer porous membrane; the above separator coating material includes inorganic particles.

[0067] It can be understood that the above separator coating material further includes a binder, and the binder includes, but is not limited to, one or more of polyvinylidene fluoride (PVDF), styrene-butadiene rubber latex (SBR), and sodium carboxymethyl cellulose (CMC); the inorganic particles include, but are not limited to, at least one of alumina, boehmite, calcium carbonate, hydrotalcite, montmorillonite, spinel, titanium dioxide, silicon dioxide, zirconia, and silicon carbide.

[0068] In a second aspect, the present invention also provides a method for preparing the above lithium-ion battery or sodium-ion battery, including the following steps: forming an electrode assembly by combining the positive electrode, negative electrode, and separator, placing the electrode assembly in a battery housing, then injecting an electrolyte to obtain a semi-finished lithium-ion or semi-finished sodium-ion battery, and subjecting the semi-finished lithium-ion or semi-finished sodium-ion battery to formation and degassing, and then sealing the liquid injection port of the battery housing to obtain a lithium-ion battery or a sodium-ion battery;

[0069] Among them, the positive electrode is obtained by coating the positive electrode coating material on a current collector, followed by drying, rolling, and slitting. The positive electrode coating material is prepared by mixing the above polymer containing a coordination group with a solvent, and then mixing with a positive electrode active material, a conductive agent, and a binder.

[0070] In some embodiments of the present application, based on the total weight of the solid content of the positive electrode coating material loaded on the current collector, the content of the polymer containing a coordination group is 0.1-10%, preferably 0.2-5%, more preferably 0.2-2%, and further preferably 0.5-2%.

[0071] In a third aspect, the present application further provides a positive electrode coating material, which comprises a positive electrode active material containing a transition metal and a polymer containing a coordination group; preferably, the positive electrode coating material further contains a conductive agent and a binder.

[0072] In a fourth aspect, the present application further provides a method for preparing the above positive electrode coating material, which includes mixing the polymer containing a coordination group with a solvent and then mixing it with a positive electrode active material, a conductive agent and a binder.

[0073] The following further elaborates the present application in combination with examples. It should be understood that these examples are only used to illustrate the present application and not to limit the scope of the present application.

[0074] The raw materials or reagents used in the present application are all purchased from mainstream manufacturers in the market. Those without indicating the manufacturer or concentration are all analytical pure grade raw materials or reagents that can be obtained conventionally. As long as they can play the expected role, there is no special limitation. The instrument and equipment used in this example are all purchased from major manufacturers in the market. As long as they can play the expected role, there is no special limitation. For those not indicating specific techniques or conditions in this example, they are carried out according to the techniques or conditions described in the literature in this field or according to the product specifications.

[0075] Reagents:

[0076] Azobisisobutyronitrile, methoxypolyethylene glycol methacrylate, 2-acrylamido-2-methylpropanesulfonic acid, N-methylpyrrolidone, boric acid, oxalic acid, acrylonitrile, methyl methacrylate, acrylamide, 2-pyridinecarboxylic acid, sulfuric acid, methanesulfonic acid, p-toluenesulfonic acid, 2-formylpyrazine, N,N-dimethylformamide, 6-cyanonicotinic acid, benzoyl peroxide, maleic anhydride, butyl acrylate, tert-butyl acrylate, 2-hydroxyethyl methacrylate, 2,2'-bipyridine-5-carboxylic acid, N,N-dimethylacrylamide, ethyl cyanoacrylate, 2-aminopyridine, cyanoacetic acid, 2-hydroxypyridine, pyromellitic acid, δ-valerolactone, succinic acid, ethylene glycol, oxalic acid, acetonitrile, hexamethylenediamine, pentamethylenediamine, 2,5-furandicarboxylic acid, thiophene-2-carboxylic acid, 2,5-thiophenedicarboxylic acid, furoic acid, tetrabutyl titanate, 2,3-pyridinedicarboxylic anhydride, 2,3-pyrazinedicarboxylic anhydride, 4,4'-diaminodiphenyl ether, adipic acid, ε-caprolactone, toluene-2,4-diisocyanate, 4,4'-biphenyletherdianhydride, 4-vinylpyridine, 4,6-diaminopyrimidine, benzidine disulfonic acid, ethyl methacrylate, etc. are all purchased from Shanghai Macklin Biochemical Co., Ltd.;

[0077] 5-Cyano-furan-2-carboxylic acid, oxazole-5-carboxylic acid, and 2-methylthiazole-5-carboxylic acid were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0078] 5-Vinylpyridinium carboxylate and allylsulfonic acid were purchased from Shenzhen Chuangxin Biotechnology Co., Ltd.;

[0079] 4-Vinylpyridin-2-amine was purchased from Shenzhen Zhenqiang Biotechnology Co., Ltd.;

[0080] 2-Vinylpyrazine and 5-cyanothiophene-2-carboxylic acid were purchased from Beijing Bailingwei Technology Co., Ltd.;

[0081] 5-Cyanothiazole-2-carboxylic acid and 1H-pyrrole-2,5-dicarboxylic acid were purchased from Shanghai Haohong Biopharmaceutical Technology Co., Ltd.;

[0082] Polycrystalline LiNi 0.8 Co 0.1 Mn 0.1 O2 was purchased from Hubei Rongbai Lithium Battery Materials Co., Ltd.;

[0083] Conductive agent( Li), PVDF binder ( 5130) was purchased from SOLVAY (SHANGHAI) Co., Ltd;

[0084] Artificial graphite was purchased from Tianjin Better New Energy Technology Co., Ltd.

[0085] Hereinafter, the present application will be described in more detail using various preparation examples, embodiments, and comparative examples, but the technical scope of the present application is not limited to these examples. It should be noted that, unless otherwise specifically stated, all percentages, parts, and ratios used in the present application are based on mass.

[0086] Preparation Example 1

[0087] 1. Add 16.4 g of azobisisobutyronitrile (AIBN, 0.1 mol), 385 g of tert-butyl acrylate (tBA, 3 mol), and 622 g of 2-acrylamido-2-methylpropanesulfonic acid (AMPS, 3 mol) to a reactor, the molar ratio of AIBN, tBA and AMPS is 1:30:30, and then add 2 kg of N-methylpyrrolidone (NMP) as a solvent, react at 70 ° C under nitrogen protection for 10 hours, and stop the reaction.

[0088] 2. Add 186 g of boric acid (3 mol) and 270 g of oxalic acid (3 mol) into a flask. The molar ratio of boric acid to oxalic acid is 1:1. Then add 1 kg of NMP as the solvent and react at 100 °C. Meanwhile, evacuate to remove the water generated during the reaction. Stop the reaction after 12 h and measure the solid content.

[0089] 3. Add the NMP solution of the product synthesized in step (2) (116 g of solid product) into the polymer solution in step (1). The molar ratio of the product in step (2) to the polymer in step (1) is 10:1. React at 100 °C and continuously remove the water generated during the reaction by evacuation. Stop the reaction after 12 h, then add 148 g of lithium carbonate and stir to react for 5 h at room temperature. Filter off the excess lithium carbonate, collect the filtrate, and dry it under vacuum to obtain polyolefin 1 containing coordination groups. The structural formula is as follows:

[0090]

[0091] Preparation Example 2

[0092] Add 32.8 g of azobisisobutyronitrile (AIBN, 0.2 mol), 636 g of acrylonitrile (AN, 12 mol), 400 g of methyl methacrylate (MMA, 4 mol), and 352 g of acrylamide (EGME, 4 mol) into a reaction kettle. The molar ratio of AIBN, AN, MMA to EGME is 1:60:20:20. Then add 1.5 kg of N-methylpyrrolidone (NMP) as the solvent and react at 70 °C under nitrogen protection for 10 h. Stop the reaction, add 492 g of 2-pyridinecarboxylic acid (4 mol) and 18 g of catalyst sulfuric acid, and react at 150 °C. Meanwhile, evacuate to remove the water generated during the reaction. Stop the reaction after 10 h, add 150 g of NaOH aqueous solution (solid content 10%) to neutralize the sulfuric acid, remove water by rotary evaporation at 80 °C, filter off the insoluble substances, collect the filtrate, and dry it under vacuum to obtain polyolefin 2 containing coordination groups. The structural formula is as follows:

[0093]

[0094] Preparation Example 3

[0095] 32.8 g of azobisisobutyronitrile (AIBN, 0.2 mol), 636 g of acrylonitrile (AN, 12 mol), 400 g of methyl methacrylate (MMA, 4 mol) and 284 g of acrylamide (MA, 4 mol) were added to a reaction kettle. The molar ratio of AIBN, AN, MMA to MA was 1:60:20:20. Then 1.2 kg of N-methylpyrrolidone (NMP) was added as a solvent, and the reaction was carried out at 70 °C under nitrogen protection for 10 h. The reaction was stopped, 496 g of pyrazine-2-carboxylic acid (4 mol) and 18 g of catalyst sulfuric acid were added, and the reaction was carried out at 150 °C. At the same time, the water generated by the reaction was removed by vacuum pumping. After 10 h, the reaction was stopped, 150 g of NaOH aqueous solution (solid content 10%) was added to neutralize the sulfuric acid, the water was removed by rotary evaporation at 80 °C, the insoluble substances were filtered off, the filtrate was collected, and vacuum drying was carried out to obtain polyolefin 3 containing a coordination group, and the structural formula was as follows:

[0096]

[0097] Preparation Example 4

[0098] 3.3 g of azobisisobutyronitrile (AIBN, 0.02 mol), 530 g of acrylonitrile (AN, 10 mol), 384 g of butyl acrylate (BA, 3 mol) and 260 g of 2-hydroxyethyl methacrylate (HEMA, 2 mol) were added to a reaction kettle. The molar ratio of AIBN, AN, BA to HEMA was 1:500:150:100. Then 1.2 kg of N,N-dimethylformamide (DMF) was added as a solvent, and the reaction was carried out at 70 °C under nitrogen protection for 10 h. The reaction was stopped, 296 g of 6-cyanonicotinic acid (4 mol) and 20 g of catalyst sulfuric acid were added, and the reaction was carried out at 120 °C. At the same time, the water generated by the reaction was removed by vacuum pumping. After 10 h, the reaction was stopped, 167 g of NaOH aqueous solution (solid content 10%) was added to neutralize the sulfuric acid, the water was removed by rotary evaporation at 80 °C, the insoluble substances were filtered off, the filtrate was collected, and vacuum drying was carried out to obtain polyolefin 4 containing a coordination group, and the structural formula was as follows:

[0099]

[0100] Preparation Example 5

[0101] 16.4 g of azobisisobutyronitrile (AIBN, 0.1 mol), 212 g of acrylonitrile (AN, 4 mol), 100 g of methyl methacrylate (MMA, 1 mol) and 240 g of 4-vinylpyridin-2-amine (2 mol) were added to a reaction kettle. The molar ratio of AIBN, AN, MMA to 4-vinylpyridin-2-amine was 1:40:10:20. Then 1 kg of N-methylpyrrolidone (NMP) was added as a solvent, and the reaction was carried out at 70 °C under nitrogen protection for 10 h. The reaction was stopped, 170 g (2 mol) of cyanoacetic acid and 20 g of p-toluenesulfonic acid as a catalyst were added, and the reaction was carried out at 150 °C. At the same time, the water generated by the reaction was removed by vacuum pumping. After 10 h, the reaction was stopped, 46 g of an aqueous NaOH solution (solid content 10%) was added to neutralize p-toluenesulfonic acid, the water was removed by rotary evaporation at 80 °C, the insoluble substances were filtered off, the filtrate was collected, and dried under vacuum to obtain polyolefin 5 containing a coordination group, and the structural formula was as follows:

[0102]

[0103] Preparation Example 6

[0104] 1.7 g of azobisisobutyronitrile (AIBN, 0.01 mol), 265 g of acrylonitrile (AN, 5 mol), 192 g of butyl acrylate (BA, 1.5 mol) and 65 g of 2-hydroxyethyl methacrylate (HEMA, 0.5 mol) were added to a reaction kettle. The molar ratio of AIBN, AN, BA to HEMA was 1:500:150:50. Then 0.8 kg of N-methylpyrrolidone (NMP) was added as a solvent, and the reaction was carried out at 70 °C under nitrogen protection for 10 h. The reaction was stopped, 100 g (0.5 mol) of 2,2'-bipyridine-5-carboxylic acid and 15 g of sulfuric acid as a catalyst were added, and the reaction was carried out at 130 °C. At the same time, the water generated by the reaction was removed by vacuum pumping. After 10 h, the reaction was stopped, 125 g of an aqueous NaOH solution (solid content 10%) was added to neutralize sulfuric acid, the water was removed by rotary evaporation at 80 °C, the insoluble substances were filtered off, the filtrate was collected, and dried under vacuum to obtain polyolefin 6 containing a coordination group, and the structural formula was as follows:

[0105]

[0106] Preparation Example 7

[0107] 8.2 g of azobisisobutyronitrile (AIBN, 0.05 mol), 106 g of acrylonitrile (AN, 2 mol), 200 g of methyl methacrylate (MMA, 2 mol), and 149 g of 5-vinylpyridine formate (VPA, 1 mol) were added to a reaction kettle. The molar ratio of AIBN, AN, MMA, and VPA was 1:40:40:20. Then, 0.5 kg of N-methylpyrrolidone (NMP) was added as a solvent, and the reaction was carried out at 70 °C under nitrogen protection for 10 h. The reaction was stopped, and 300 g of an aqueous LiOH solution (solid content 8%) was added to neutralize the carboxyl group. After vacuum drying, a polyolefin 7 containing a coordination group was obtained, and the structural formula was as follows:

[0108]

[0109] Preparation Example 8

[0110] 24.2 g of benzoyl peroxide (BPO, 0.1 mol), 530 g of acrylonitrile (AN, 3 mol), 198 g of N,N-dimethylacrylamide (DMAA, 2 mol), and 144 g of acrylic acid (AA, 2 mol) were added to a reaction kettle. The molar ratio of BPO, AN, DMAA, and AA was 1:30:20:20. Then, 1.0 kg of N,N-dimethylformamide (DMF) was added as a solvent, and the reaction was carried out at 90 °C under nitrogen protection for 10 h. The reaction was stopped, 2-aminopyridine (188 g, 2 mol) and 20 g of p-toluenesulfonic acid as a catalyst were added, and the reaction was carried out at 150 °C. At the same time, the water generated by the reaction was removed by vacuum. After 10 h, the reaction was stopped, 46 g of an aqueous NaOH solution (solid content 10%) was added to neutralize p-toluenesulfonic acid, the water was removed by rotary evaporation at 80 °C, the insoluble substances were filtered off, the filtrate was collected, and after vacuum drying, a polyolefin 8 containing a coordination group was obtained, and the structural formula was as follows:

[0111]

[0112] Preparation Example 9

[0113] 1.7 g of azobisisobutyronitrile (AIBN, 0.01 mol), 159 g of acrylonitrile (AN, 3 mol), 64 g of butyl acrylate (BA, 0.5 mol) and 195 g of 2-hydroxyethyl methacrylate (HEMA, 1.5 mol) were added to a reaction kettle. The molar ratio of AIBN, AN, BA to HEMA was 1:300:50:150. Then 0.5 kg of N-methylpyrrolidone (NMP) was added as a solvent, and the reaction was carried out at 70 °C under nitrogen protection for 10 h. The reaction was stopped, 128 g of cyanoacetic acid (1.5 mol), 12 g of the catalyst 4-dimethylaminopyridine (DMAP) and 100 g of the dehydrating agent N,N'-dicyclohexylcarbodiimide (DCC) were added, and the reaction was carried out at 80 °C. After 10 h, the reaction was stopped, the insoluble substances were filtered off, the filtrate was collected, and dried under vacuum to obtain a polyolefin 9 containing a coordination group, and the structural formula was as follows:

[0114]

[0115] Preparation Example 10

[0116] 1.7 g of azobisisobutyronitrile (AIBN, 0.01 mol), 42 g of acrylonitrile (AN, 0.8 mol), 26 g of butyl acrylate (BA, 0.2 mol) and 26 g of 2-hydroxyethyl methacrylate (HEMA, 0.2 mol) were added to a reaction kettle. The molar ratio of AIBN, AN, BA to HEMA was 1:80:20:20. Then 0.5 kg of N-methylpyrrolidone (NMP) was added as a solvent, and the reaction was carried out at 70 °C under nitrogen protection for 10 h. The reaction was stopped, 26 g of picolinic acid (0.2 mol), 6 g of the catalyst 4-dimethylaminopyridine (DMAP) and 42 g of the dehydrating agent N,N'-dicyclohexylcarbodiimide (DCC) were added, and the reaction was carried out at 80 °C. After 10 h, the reaction was stopped, the insoluble substances were filtered off, the filtrate was collected, and dried under vacuum to obtain a polyolefin 10 containing a coordination group, and the structural formula was as follows:

[0117]

[0118] Preparation Example 11

[0119] 1.7 g of azobisisobutyronitrile (AIBN, 0.01 mol), 42 g of acrylonitrile (AN, 0.8 mol), 26 g of butyl acrylate (BA, 0.2 mol) and 26 g of 2-hydroxyethyl methacrylate (HEMA, 0.2 mol) were added to a reaction kettle. The molar ratio of AIBN, AN, BA and HEMA was 1:80:20:20. Then 0.5 kg of N-methylpyrrolidone (NMP) was added as a solvent, and the reaction was carried out at 70 °C under nitrogen protection for 10 h. The reaction was stopped, 22.6 g of oxazole-5-carboxylic acid (0.2 mol), 6 g of catalyst 4-dimethylaminopyridine (DMAP) and 42 g of dehydrating agent N,N'-dicyclohexylcarbodiimide (DCC) were added, and the reaction was carried out at 80 °C. After 10 h, the reaction was stopped, the insoluble substances were filtered off, the filtrate was collected, dried under vacuum, and polyolefin 11 containing a coordination group was obtained. The structural formula is as follows:

[0120]

[0121] Preparation Example 12

[0122] 1.7 g of azobisisobutyronitrile (AIBN, 0.01 mol), 42 g of acrylonitrile (AN, 0.8 mol), 26 g of butyl acrylate (BA, 0.2 mol) and 26 g of 2-hydroxyethyl methacrylate (HEMA, 0.2 mol) were added to a reaction kettle. The molar ratio of AIBN, AN, BA and HEMA was 1:80:20:20. Then 0.5 kg of N-methylpyrrolidone (NMP) was added as a solvent, and the reaction was carried out at 70 °C under nitrogen protection for 10 h. The reaction was stopped, 28.6 g of 2-methylthiazole-5-carboxylic acid (0.2 mol), 6 g of catalyst 4-dimethylaminopyridine (DMAP) and 42 g of dehydrating agent N,N'-dicyclohexylcarbodiimide (DCC) were added, and the reaction was carried out at 80 °C. After 10 h, the reaction was stopped, the insoluble substances were filtered off, the filtrate was collected, dried under vacuum, and polyolefin 12 containing a coordination group was obtained. The structural formula is as follows:

[0123]

[0124] Preparation Example 13

[0125] 1. 16.4 g of azobisisobutyronitrile (AIBN, 0.1 mol), 228 g of ethyl methacrylate (EMA, 2 mol), 216 g of acrylic acid (AA, 3 mol) and 610 g of allyl sulfonic acid (ASA, 5 mol) were added to a reaction kettle. The molar ratio of AIBN, tBA, AA and ASA was 1:20:30:50. Then

[0126] 1.2 kg of N-methylpyrrolidone (NMP) was added as a solvent, and the reaction was carried out at 70 °C under nitrogen protection for 10 h. The reaction was stopped.

[0127] 2. Add 186 g of boric acid (3 mol) and 270 g of oxalic acid (3 mol) into a flask. The molar ratio of boric acid to oxalic acid is 1:1. Then add 1 kg of NMP as the solvent and react at 100 °C. At the same time, evacuate to remove the water generated during the reaction. Stop the reaction after 12 h and measure the solid content.

[0128] 3. Add the NMP solution of the product synthesized in step (2) (116 g of solid product) into the polymer solution of step (1). The molar ratio of the product in step (2) to the polymer in step (1) is 30:1. React at 100 °C and continuously remove the water generated during the reaction by evacuation. Stop the reaction after 12 h, then add 150 g of lithium carbonate, stir and react at room temperature for 5 h, filter off the excess lithium carbonate, collect the filtrate, and dry it under vacuum to obtain polyolefin 13 containing coordination groups, with the structural formula as follows:

[0129]

[0130] Preparation Example 14

[0131] Add 1.7 g of azobisisobutyronitrile (AIBN, 0.01 mol), 42 g of acrylonitrile (AN, 0.8 mol), 26 g of butyl acrylate (BA, 0.2 mol), and 26 g of 2-hydroxyethyl methacrylate (HEMA, 0.2 mol) into a reaction kettle. The molar ratio of AIBN, AN, BA, and HEMA is 1:80:20:20. Then add 0.5 kg of N-methylpyrrolidone (NMP) as the solvent and react at 70 °C under nitrogen protection for 10 h. Stop the reaction, add 27.4 g of 5-cyano-furan-2-carboxylic acid (0.2 mol), 6 g of the catalyst 4-dimethylaminopyridine (DMAP), and 42 g of the dehydrating agent N,N'-dicyclohexylcarbodiimide (DCC), and react at 80 °C. Stop the reaction after 10 h, filter off the insoluble substances, collect the filtrate, and dry it under vacuum to obtain polyolefin 14 containing coordination groups, with the structural formula as follows:

[0132]

[0133] Preparation Example 15

[0134] 1.7 g of azobisisobutyronitrile (AIBN, 0.01 mol), 42 g of acrylonitrile (AN, 0.8 mol), 26 g of butyl acrylate (BA, 0.2 mol) and 26 g of 2-hydroxyethyl methacrylate (HEMA, 0.2 mol) were added to a reaction kettle. The molar ratio of AIBN, AN, BA and HEMA was 1:80:20:20. Then 0.5 kg of N-methylpyrrolidone (NMP) was added as a solvent, and the reaction was carried out at 70 °C under nitrogen protection for 10 h. The reaction was stopped, 30.6 g of 5-cyanothiophene-2-carboxylic acid (0.2 mol), 6 g of catalyst 4-dimethylaminopyridine (DMAP) and 42 g of dehydrating agent N,N'-dicyclohexylcarbodiimide (DCC) were added, and the reaction was carried out at 80 °C. After 10 h, the reaction was stopped, the insoluble substances were filtered off, the filtrate was collected, and vacuum drying was carried out to obtain polyolefin 15 containing a coordination group, and the structural formula was as follows:

[0135]

[0136] Preparation Example 16

[0137] 1.7 g of azobisisobutyronitrile (AIBN, 0.01 mol), 42 g of acrylonitrile (AN, 0.8 mol), 26 g of butyl acrylate (BA, 0.2 mol) and 26 g of 2-hydroxyethyl methacrylate (HEMA, 0.2 mol) were added to a reaction kettle. The molar ratio of AIBN, AN, BA and HEMA was 1:80:20:20. Then 0.5 kg of N-methylpyrrolidone (NMP) was added as a solvent, and the reaction was carried out at 70 °C under nitrogen protection for 10 h. The reaction was stopped, 30.6 g of 5-cyanothiazole-2-carboxylic acid (0.2 mol), 6 g of catalyst 4-dimethylaminopyridine (DMAP) and 42 g of dehydrating agent N,N'-dicyclohexylcarbodiimide (DCC) were added, and the reaction was carried out at 80 °C. After 10 h, the reaction was stopped, the insoluble substances were filtered off, the filtrate was collected, and vacuum drying was carried out to obtain polyolefin 16 containing a coordination group, and the structural formula was as follows:

[0138]

[0139] Preparation Example 17

[0140] 1.7 g of azobisisobutyronitrile (AIBN, 0.01 mol), 42 g of acrylonitrile (AN, 0.8 mol) and 25 g of ethyl cyanoacrylate (ECA, 0.2 mol) were added to a reaction kettle. The molar ratio of AIBN, AN and ECA was 1:80:20. Then 0.12 kg of N-methylpyrrolidone (NMP) was added as a solvent, and the reaction was carried out at 70 °C under nitrogen protection for 10 h. The reaction was stopped, and vacuum drying was carried out to obtain polyolefin 17 containing a coordination group, and the structural formula was as follows:

[0141]

[0142] Preparation Example 18

[0143] 1.7 g of azobisisobutyronitrile (AIBN, 0.01 mol), 42 g of acrylonitrile (AN, 0.8 mol), 26 g of butyl acrylate (BA, 0.2 mol) and 8.6 g of methacrylic acid (MAA, 0.1 mol) were added to a reaction kettle. The molar ratio of AIBN, AN, BA and MAA was 1:80:20:10. Then, 0.2 kg of N-methylpyrrolidone (NMP) was added as a solvent, and the reaction was carried out at 70 °C under nitrogen protection for 10 h. The reaction was stopped, 30 g of an aqueous LiOH solution (solid content 8%) was added to neutralize the carboxyl group, and vacuum drying was carried out to obtain polyolefin 18 containing a coordination group, and the structural formula was as follows:

[0144]

[0145] Preparation Example 19

[0146] 8.2 g of azobisisobutyronitrile (AIBN, 0.05 mol), 100 g of methyl methacrylate (MMA, 1 mol) and 72 g of acrylic acid (AA, 1 mol) were added to a reaction kettle. The molar ratio of AIBN, MMA and AA was 1:20:20. Then, 0.3 kg of N-methylpyrrolidone (NMP) was added as a solvent, and the reaction was carried out at 70 °C under nitrogen protection for 10 h. The reaction was stopped, 300 g of an aqueous LiOH solution (solid content 8%) was added to neutralize the carboxyl group, and vacuum drying was carried out to obtain polyolefin 19 containing a coordination group, and the structural formula was as follows:

[0147]

[0148] Preparation Example 20

[0149] 8.2 g of azobisisobutyronitrile (AIBN, 0.05 mol), 183 g of allyl sulfonic acid (ASA, 1.5 mol), 98 g of N,N-dimethylacrylamide (DMAA, 1 mol) and 263 g of 4-vinylpyridine (VP, 2.5 mol) were added to a reaction kettle. The molar ratio of AIBN, ASA, DMAA and VP was 1:30:20:50. Then, 0.8 kg of N-methylpyrrolidone (NMP) was added as a solvent, and the reaction was carried out at 70 °C under nitrogen protection for 10 h. The reaction was stopped and vacuum drying was carried out to obtain polyolefin 20 containing a coordination group, and the structural formula was as follows:

[0150]

[0151] Preparation Example 21

[0152] 3.3 g of azobisisobutyronitrile (AIBN, 0.02 mol), 60 g of methyl methacrylate (MMA, 0.6 mol) and 106 g of 2-vinylpyrazine (1 mol) were added to a reaction kettle. The molar ratio of AIBN, MMA and 2-vinylpyrazine was 1:30:50. Then, 0.3 kg of N-methylpyrrolidone (NMP) was added as a solvent. The reaction was carried out at 70 °C under nitrogen protection for 10 h. The reaction was stopped and vacuum dried to obtain polyolefin 21 containing a coordination group, and the structural formula was as follows:

[0153]

[0154] Preparation Example 22

[0155] 1.7 g of azobisisobutyronitrile (AIBN, 0.01 mol), 27 g of acrylonitrile (AN, 0.5 mol), 102 g of butyl acrylate (BA, 0.8 mol) and 26 g of 2-hydroxyethyl methacrylate (HEMA, 0.2 mol) were added to a reaction kettle. The molar ratio of AIBN, AN, BA and HEMA was 1:50:80:20. Then, 0.5 kg of N-methylpyrrolidone (NMP) was added as a solvent. The reaction was carried out at 70 °C under nitrogen protection for 10 h. The reaction was stopped, 26 g of 2-pyridinecarboxylic acid (0.2 mol), 6 g of catalyst 4-dimethylaminopyridine (DMAP) and 42 g of dehydrating agent N,N'-dicyclohexylcarbodiimide (DCC) were added, and the reaction was carried out at 80 °C. After 10 h, the reaction was stopped, the insoluble substances were filtered off, the filtrate was collected and vacuum dried to obtain polyolefin 22 containing a coordination group, and the structural formula was as follows:

[0156]

[0157] Preparation Example 23

[0158] 16.4 g of azobisisobutyronitrile (AIBN, 0.1 mol) and 315 g of 4-vinylpyridine (VP, 3 mol) were added to a reaction kettle. The molar ratio of AIBN and VP was 1:30. Then, 0.6 kg of N-methylpyrrolidone (NMP) was added as a solvent. The reaction was carried out at 70 °C under nitrogen protection for 10 h. The reaction was stopped and vacuum dried to obtain polyolefin 23 containing a coordination group, and the structural formula was as follows:

[0159]

[0160] Preparation Example 24

[0161] Add 354 g of succinic acid (3 mol) and 233 g of ethylene glycol (3.75 mol) into a reaction kettle. The molar ratio of succinic acid to ethylene glycol is 1:1.25. Then add 5 g of p-toluenesulfonic acid as a catalyst. Evacuate the air, react at 160 °C for 10 h, add 185 g of 2-pyridinecarboxylic acid (PA, 1.5 mol), continue to react at 160 °C for 8 h. After stopping the reaction, add N,N-dimethylformamide (DMF) to dissolve, then add 4 g of NaOH aqueous solution (solid content 30%) to neutralize p-toluenesulfonic acid. Rotary evaporate to remove water at 80 °C, filter off the insoluble substances, collect the filtrate, evacuate and dry to obtain the final product, polyester 1 containing coordination groups, and the structural formula is as follows:

[0162]

[0163] Preparation Example 25

[0164] Add 50.8 g of dried pyromellitic acid (0.2 mol) and 240 g of δ-valerolactone monomer (1.2 mol) into a reaction kettle. Then add 300 g of solvent N,N-dimethylformamide (DMF) and 2 g of catalyst sulfuric acid. React at 110 °C for 12 h, add 76 g of 2-hydroxypyridine (0.8 mol), raise the temperature to 120 °C and continue to react for 6 h. Stop the reaction, then add 6.5 g of NaOH aqueous solution (solid content 25%) to neutralize sulfuric acid. Rotary evaporate to remove water at 80 °C, filter off the insoluble substances, collect the filtrate, evacuate and dry to obtain the final product, polyester 2 containing coordination groups, and the structural formula is as follows:

[0165]

[0166] Preparation Example 26

[0167] Add 401 g of pyridine-2,6-dicarboxylic acid (2.4 mol) and 124 g of ethylene glycol (2 mol) into a reaction kettle. The molar ratio of pyridine-2,6-dicarboxylic acid to ethylene glycol is 1.2:1. Then add 600 g of solvent N-methylpyrrolidone (NMP) and 5 g of catalyst p-toluenesulfonic acid. Evacuate the air, react at 160 °C for 10 h. Stop the reaction, then add 250 g of LiOH aqueous solution (solid content 8%) to neutralize the carboxyl group and p-toluenesulfonic acid. Rotary evaporate to remove water at 80 °C, filter off the insoluble substances, collect the filtrate, evacuate and dry to obtain the final product, polyester 3 containing coordination groups, and the structural formula is as follows:

[0168]

[0169] Preparation Example 27

[0170] Add 295 g of succinic acid (2.5 mol) and 124 g of ethylene glycol (2 mol) to the reaction kettle. The molar ratio of succinic acid to ethylene glycol is 1.25:1. Then add 5 g of p-toluenesulfonic acid as a catalyst, evacuate the air, react at 160 °C for 10 h, add 55 g of 4,6-diaminopyrimidine (0.5 mol), continue to react at 160 °C for 8 h. After stopping the reaction, add N-methylpyrrolidone (NMP) to dissolve, and then add 6 g of NaOH aqueous solution (solid content 20%) to neutralize p-toluenesulfonic acid. Rotate and evaporate to remove water at 80 °C, filter off the insoluble substances, collect the filtrate, evacuate and dry to obtain the final product, a polyester 4 containing a coordination group, with the structural formula as follows, where n is an integer greater than or equal to 1:

[0171]

[0172] Preparation Example 28

[0173] Add 347 g of oxalic acid (3.75 mol) and 186 g of ethylene glycol (3 mol) to the reaction kettle. The molar ratio of oxalic acid to ethylene glycol is 1.25:1. Then add 3 g of p-toluenesulfonic acid as a catalyst, evacuate the air, react at 160 °C for 10 h. After stopping the reaction, add acetonitrile to dissolve, and then add LiOH aqueous solution to adjust the pH to 7.0. Evacuate and dry to obtain the final product, a polyester 5 containing a coordination group, with the structural formula as follows:

[0174]

[0175] Preparation Example 29

[0176] Add 390 g of 2,5-furandicarboxylic acid (2.5 mol) and 124 g of ethylene glycol (2 mol) to the reaction kettle. The molar ratio of 2,5-furandicarboxylic acid to ethylene glycol is 1.25:1. Then add 200 g of the solvent N-methylpyrrolidone (NMP) and 5 g of the catalyst tetrabutyl titanate, evacuate the air, react at 170 °C for 10 h. After stopping the reaction, add 300 g of LiOH aqueous solution (solid content 8%) to neutralize the carboxyl group. Rotate and evaporate to remove water at 80 °C, filter off the insoluble substances, collect the filtrate, evacuate and dry to obtain the final product, a polyester 6 containing a coordination group, with the structural formula as follows:

[0177]

[0178] Preparation Example 30

[0179] Add 388 g of 1H-pyrrole-2,5-dicarboxylic acid (2.5 mol) and 124 g of ethylene glycol (2 mol) to the reaction kettle. The molar ratio of 2,5-furandicarboxylic acid to ethylene glycol is 1.25:1. Then add 200 g of the solvent N-methylpyrrolidone (NMP) and 5 g of the catalyst tetrabutyl titanate. Evacuate the air, react at 170 °C for 10 h, stop the reaction, then add 300 g of an aqueous LiOH solution (solid content 8%) to neutralize the carboxyl groups, remove water by rotary evaporation at 80 °C, filter off the insoluble substances, collect the filtrate, and dry it under vacuum. The final product obtained is a polyester 7 containing a coordination group, and the structural formula is as follows:

[0180]

[0181] Preparation Example 31

[0182] Add 3.1 g of ethylene glycol (0.05 mol) and 285 g of ε-caprolactone (CL, 2.5 mol) to the reaction kettle. The molar ratio of ethylene glycol to ε-caprolactone is 1:50. Add 2 g of methanesulfonic acid as the catalyst, evacuate the air and react at 100 °C for 12 h. After stopping the reaction, dissolve it with N-methylpyrrolidone (NMP), add 12.3 g of 2-pyridinecarboxylic acid (0.1 mol), raise the temperature to 120 °C and continue to react for 6 h. Stop the reaction, then add 6.5 g of an aqueous NaOH solution (solid content 25%) to neutralize the sulfuric acid, remove water by rotary evaporation at 80 °C, filter off the insoluble substances, collect the filtrate, and dry it under vacuum. The final product obtained is a polyester 8 containing a coordination group, and the structural formula is as follows:

[0183]

[0184] Preparation Example 32

[0185] Add 278 g of hexamethylenediamine (2.4 mol) and 332 g of terephthalic acid (2 mol) to the reaction kettle. The molar ratio of hexamethylenediamine to terephthalic acid is 1.2:1. React under vacuum at 250 °C for 12 h. After stopping the reaction, dissolve it with 2 kg of N-methylpyrrolidone (NMP), then add 60 g of 2,3-pyridinedicarboxylic anhydride (0.4 mol), react at room temperature for 48 h, and then transfer it to a vacuum oven for stepwise temperature-raising reaction. React at 160 °C for 1 h, 200 °C for 30 min, and 230 °C for 30 min. Evacuate the air. The final product obtained is a polyamide 1 containing a coordination group, and the structural formula is as follows:

[0186]

[0187] Preparation Example 33

[0188] Add 161 g of adipic acid (1.1 mol) and 109 g of 2,6-diaminopyridine (1 mol) to the reaction kettle. The molar ratio of adipic acid to 2,6-diaminopyridine is 1.1:1. React under vacuum at 250 °C for 12 h. Then add 19 g of 2-hydroxypyridine (0.2 mol) and 5 g of sulfuric acid, and continue to react under vacuum at 100 °C for 6 h. After stopping the reaction, add N-methylpyrrolidone (NMP) to dissolve, then add 20 g of NaOH aqueous solution (solid content 20%) to neutralize the sulfuric acid. Remove water by rotary evaporation at 80 °C, filter off the insoluble substances, collect the filtrate, and dry it under vacuum. The final product obtained is polyamide 2 containing a coordination group, and the structural formula is as follows:

[0189]

[0190] Preparation Example 34

[0191] Add 183 g of adipic acid (1.25 mol) and 200 g of 4,4'-diaminodiphenyl ether (1 mol) to the reaction kettle. The molar ratio of adipic acid to 4,4'-diaminodiphenyl ether is 1.25:1. React under vacuum at 250 °C for 12 h. Then add 55 g of 3-hydroxypentanedinitrile (0.5 mol) and 5 g of sulfuric acid, and continue to react under vacuum at 100 °C for 6 h. After stopping the reaction, add N-methylpyrrolidone (NMP) to dissolve, then add 20 g of NaOH aqueous solution (solid content 20%) to neutralize the sulfuric acid. Remove water by rotary evaporation at 80 °C, filter off the insoluble substances, collect the filtrate, and dry it under vacuum. The final product obtained is polyamide 3 containing a coordination group, and the structural formula is as follows:

[0192]

[0193] Preparation Example 35

[0194] Add 245 g of pentamethylenediamine (2.4 mol), 312 g of 2,5-furandicarboxylic acid (2 mol) and 5 g of p-toluenesulfonic acid to the reaction kettle. The molar ratio of pentamethylenediamine to 2,5-furandicarboxylic acid is 1.2:1. React under vacuum at 200 °C for 12 h. Then add 45 g of furoic acid (0.4 mol), and continue to react at 200 °C for 5 h. Stop the reaction, dissolve the product in N-methylpyrrolidone (NMP), precipitate it in a large amount of dimethyl carbonate (DMC), collect the solid, and dry it under vacuum. The final product obtained is polyamide 4 containing a coordination group, and the structural formula is as follows:

[0195]

[0196] Preparation Example 36

[0197] Add 245 g of pentamethylenediamine (2.4 mol), 344 g of 2,5-thiophenedicarboxylic acid (2 mol) and 5 g of p-toluenesulfonic acid into a reaction kettle. The molar ratio of pentamethylenediamine to 2,5-thiophenedicarboxylic acid is 1.2:1. React under vacuum condition at 200 °C for 12 h, then add 51 g of thiophene-2-carboxylic acid (0.4 mol), continue to react at 200 °C for 5 h, stop the reaction, dissolve the product in N-methylpyrrolidone (NMP), precipitate in a large amount of dimethyl carbonate (DMC), collect the solid, and dry it under vacuum. The final product obtained is polyamide 5 containing a coordination group, and the structural formula is as follows:

[0198]

[0199] Preparation Example 37

[0200] Add 167 g of pyridine-2,6-dicarboxylic acid (1 mol) and 74 g of ethylene glycol (1.2 mol) into a reaction kettle. The molar ratio of pyridine-2,6-dicarboxylic acid to ethylene glycol is 1:1.2. Then add 100 g of the solvent N-methylpyrrolidone (NMP) and 1 g of the catalyst tetrabutyl titanate, evacuate, react at 160 °C for 10 h, stop the reaction, then add 35 g of toluene-2,4-diisocyanate (TDI, 0.2 mol). The molar ratio of pyridine-2,6-dicarboxylic acid to TDI is 5:1. Continue to react at 60 °C for 8 h, stop the reaction, and dry under vacuum. The final product obtained is polyurethane 1 containing a coordination group, and the structural formula is as follows, where n is an integer greater than or equal to 1:

[0201]

[0202] Preparation Example 38

[0203] Add 310 g of 4,4'-oxydiphthalic dianhydride (ODPA, 1 mol) and 361 g of benzidine disulfonic acid (BDSA, 1.05 mol) into a reaction kettle. The molar ratio of ODPA to BDSA is 1:1.05. Add 1.5 kg of N-methylpyrrolidone (NMP) as the solvent, stir and react at room temperature for 48 h, then add 15 g of 2,3-pyrazinedicarboxylic anhydride (0.1 mol), and continue to stir and react at room temperature for 24 h. Transfer the reaction solution to a vacuum oven for stepwise temperature-raising reaction, react at 160 °C for 1 h, react at 250 °C for 1 h, evacuate, and the final product obtained is polyimide 1 containing a coordination group, and the structural formula is as follows:

[0204]

[0205] Use the following method to test the basic properties of the polymers prepared above, and the measurement results are shown in Table 1.

[0206] (1) Molecular weight measurement:

[0207] The absolute molecular weight of the above polymer was determined by gel permeation chromatography - multi - angle laser light scattering (GPC - MALLS). The gel chromatograph was a Waters 1515 GPC gel chromatograph from the United States, and the light scattering detector was a DAWN HELEOS - II light scattering detector from Wyatt Technology Corporation, USA.

[0208] (2) Determination of the swelling degree:

[0209] The above polymer was made into circular film pieces with a thickness of 30 μm and a size of 16 mm * 16 mm. The mass of the film pieces was weighed. The film pieces were immersed in 10 g of electrolyte, sealed and stored at 45 °C. The film pieces were taken out every 8 h, the electrolyte on the surface was wiped off, the thickness and mass were measured, and then they were put back into the electrolyte, sealed and continued to be stored at 45 °C until the thickness and mass of the film pieces remained unchanged for three consecutive tests, then it was considered that the polymer film pieces reached the swelling equilibrium state. The swelling degree was calculated according to the following formula: The mass difference before and after soaking in the electrolyte / the mass of the film piece before soaking * 100% is the swelling degree of the polymer.

[0210]

[0211] In the above formula, m0 represents the mass of the polymer film piece before soaking in the electrolyte, and m1 represents the mass of the polymer film piece after reaching the swelling equilibrium after soaking in the electrolyte.

[0212] Among them, the electrolyte was prepared as follows: In a glove box with a dew point lower than - 40 °C, lithium hexafluorophosphate (LiPF6) was dissolved in a mixture of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) (the volume ratio of EC to EMC was 3:7) to prepare an electrolyte with a concentration of LiPF6 of 1.2 mol / L, and then 1.5% of vinylene carbonate (VC) and 1% of 1,3 - propane sultone (1,3 - PS) were added based on the weight of the whole electrolyte to obtain the required electrolyte.

[0213] (3) Determination of the swelling loss rate

[0214] The above polymer was made into circular film pieces with a thickness of 30 μm and a size of 16 mm * 16 mm. The mass of the film pieces was weighed. The film pieces were immersed in 10 g of electrolyte, sealed and stored at 45 °C. The film pieces were taken out every 8 h, the electrolyte on the surface was wiped off, the thickness and mass were measured, and then they were put back into the electrolyte, sealed and continued to be stored at 45 °C until the thickness and mass of the film pieces remained unchanged for three consecutive tests. The excess electrolyte and lithium salt on the film pieces were rinsed off with dimethyl carbonate (DMC) solvent, and then completely dried in an oven, and the mass of the remaining film pieces after drying was weighed. The swelling loss rate was calculated according to the following formula:

[0215]

[0216] In the above formula, m0 represents the mass of the polymer membrane before soaking in the electrolyte, with the unit of g, and m2 represents the mass of the remaining polymer membrane after soaking in the electrolyte and then being washed and dried, with the unit of g.

[0217] Among them, the electrolyte is prepared as follows: In a glove box with a dew point lower than -40 °C, lithium hexafluorophosphate (LiPF6) is dissolved in a mixture of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) (the volume ratio of EC to EMC is 3:7) to prepare an electrolyte with a LiPF6 concentration of 1.2 mol / L, and then 1.5% of vinylene carbonate (VC) and 1% of 1,3 - propane sultone (1,3 - PS) by weight of the whole electrolyte are added to obtain the required electrolyte.

[0218] Example 1

[0219] 1. Fabrication of the battery

[0220] 1.1 Preparation of the positive electrode plate

[0221] The positive electrode active material LiNi 0.8 Co 0.1 Mn 0.1 O2, carbon black conductive agent ( Li), PVDF binder ( 5130) are mixed in a weight ratio of 96.5:1.5:2 and put into a double - planetary mixer. The total weight of the positive electrode active material, carbon black conductive agent and binder is 1 kg, 0.5 kg of N - methyl pyrrolidone (NMP) is added, and after stirring evenly, the NMP solution of polyolefin 1 prepared in Preparation Example 1 (solid content 20%) is added. Among them, based on the total weight of the solid matter of the positive electrode coating material, the addition amount of polyolefin 1 is 1%. After continuing to stir evenly, the positive electrode material slurry is obtained through filtration by a filter screen, and the solid content of the slurry is 65%. Then, the slurry is coated on both sides of an aluminum foil with a thickness of 12 μm by an extrusion coater, and after baking and hot roll pressing, a positive electrode plate is obtained. The areal density of the single - side coating of the positive electrode plate is 20 mg / cm 2 .

[0222] 1.2 Preparation of the negative electrode plate

[0223] The negative electrode active material artificial graphite, carbon black conductive agent ( (Li), sodium carboxymethyl cellulose (CMC) are mixed in a weight ratio of 97:1.5:1.5 and then put into a double planetary mixer. The total weight of the negative electrode active material, carbon black conductive agent and sodium carboxymethyl cellulose is 1 kg, 0.8 kg of deionized water (DIW) is added, and after stirring evenly, styrene-butadiene rubber latex (SBR) with a solid content of 50% and accounting for 1% of the total solid content of the negative electrode material is added. After continuing to stir evenly, the negative electrode material slurry is obtained through filtration with a filter screen, and the solid content of the slurry is 45%. Then, the slurry is coated on both sides of a copper foil with a thickness of 6 μm by an extrusion coater, and after baking and hot roll pressing, a negative electrode plate is obtained, and the areal density of the single-sided coating of the negative electrode plate is 13 mg / cm 2 .

[0224] 1.3 Preparation of dry electric core

[0225] The above-mentioned positive electrode plate, the above-mentioned negative electrode plate, and a commercially available PE separator with boehmite coatings on both sides are cut into certain shapes. Among them, the size of the active material area on the positive electrode plate is 48 mm×44 mm, the size of the active material area on the negative electrode plate is 52 mm×46 mm, and the size of the separator is 56 mm×50 mm. And current collector lead-out parts are left on the positive electrode plate and the negative electrode plate respectively; then they are stacked layer by layer in the order of negative electrode plate, separator, positive electrode plate, separator, negative electrode plate,... There are 18 positive electrode plates and 19 negative electrode plates in total, and the outermost layer is the negative electrode plate; then the current collector lead-out parts of the positive electrode plates are welded together by an ultrasonic welder, and a positive electrode tab is welded, and the current collector lead-out parts of the negative electrode plates are welded together by an ultrasonic welder, and a negative electrode tab is welded, thus obtaining a stacked body.

[0226] The above-mentioned stacked body is put into a packaging bag made of two aluminum-plastic films after shell punching, and the hot melt adhesive on the tab is welded to the packaging bag by a hot melt method. The tabs are led out of the packaging bag, and an airbag and a liquid injection port are left on one side of the packaging bag, thus obtaining a dry electric core.

[0227] 1.4 Preparation of electrolyte

[0228] In a glove box with a dew point lower than -40 °C, lithium hexafluorophosphate (LiPF6) is dissolved in a mixture of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) (the volume ratio of EC to EMC is 3:7) to prepare an electrolyte with a concentration of LiPF6 of 1.2 mol / L, and then vinylene carbonate (VC) accounting for 1.5% of the total weight of the whole electrolyte and 1,3 - propane sultone (1,3 - PS) accounting for 1% are added to obtain the required electrolyte.

[0229] 1.5 Preparation of battery

[0230] Inject the above electrolyte into the dry battery cell through the liquid injection port in a glove box with a dew point lower than -40°C. After standing for 24 hours, seal the liquid injection port outside the airbag with a vacuum heat sealer and at the same time evacuate the gas in the battery cell, thus obtaining an unformed battery cell. Weigh the unformed battery cell, and subtract the weight of the dry battery cell to obtain the weight of the injected electrolyte.

[0231] 1.6 Formation of the battery

[0232] Form the battery cell with a charge-discharge device. First, charge it at a constant current of 0.05C until 3.6V, then use a vacuum heat sealer to evacuate and seal it and cut off the airbag, then charge it at a constant current of 0.2C until 4.2V, then charge it at a constant voltage until the current drops to 0.05C, and then discharge it at a constant current of 0.2C until 3.0V, thus obtaining a well-formed battery cell, which is the gel electrolyte lithium-ion battery of the present invention.

[0233] 2. Testing of the battery

[0234] 2.1 Testing of the initial discharge capacity

[0235] At room temperature, charge the well-formed battery at a constant current of 1C until 4.2V, then charge it at a constant voltage until the current drops to 0.05C, and then discharge it at a constant current of 1C until 3.0V to obtain the initial discharge capacity (Ah). Then, some of the batteries are subjected to high-temperature storage testing, and the other part of the batteries are subjected to charge-discharge cycle testing.

[0236] 2.2 Testing of the internal resistance

[0237] Charge the battery to a half-charged state, connect the test fixture to the internal resistance tester, and clamp the corresponding positive and negative electrodes of the battery respectively, and test the AC impedance of the battery at 1KHz, which is the internal resistance of the battery.

[0238] 2.3 High-temperature storage testing

[0239] At room temperature, charge the battery at a constant current of 1C until 4.2V, then charge it at a constant voltage until the current drops to 0.05C, and then transfer the battery to an oven at 60°C for storage for 7 days. Take out the battery and measure its thickness, and calculate the thickness expansion rate compared with the thickness before high-temperature storage, that is, the thickness expansion rate = (the thickness of the battery after high-temperature storage - the thickness of the battery before high-temperature storage) / the thickness of the battery before high-temperature storage * 100%;

[0240] After the battery cools down to room temperature, discharge it at a constant current of 1C until 3.0V, and calculate the capacity retention rate compared with the discharge capacity before high-temperature storage, that is, the capacity retention rate = the discharge capacity after high-temperature storage / the discharge capacity before high-temperature storage * 100%;

[0241] After that, the battery is charged at a constant current of 1C until 4.2V, then charged at a constant voltage until the current drops to 0.05C, and then discharged at a constant current of 1C until 3.0V. The capacity recovery rate is calculated by comparing the discharge capacity obtained with the discharge capacity before high-temperature storage, that is, capacity recovery rate = discharge capacity after recharging and discharging after high-temperature storage / discharge capacity before high-temperature storage * 100%.

[0242] 2.4 Charge and discharge cycle test

[0243] The battery is charged at a constant current of 1C until 4.2V at room temperature (25°C) and high temperature (45°C) respectively, then charged at a constant voltage until the current drops to 0.05C, and then discharged at a constant current of 1C until 3.0V. Such a cycle is carried out for 1000 weeks, and the discharge capacity retention rate is calculated by comparing the discharge capacity of the last time with that of the first time.

[0244] 2.5 Thermal box test

[0245] The battery heating experiment is carried out with reference to GB / T 31485-2015. The battery is placed in a temperature chamber and heated from room temperature to 130°C ± 2°C at a rate of 5°C / min and maintained at this temperature for 30min. If there is no abnormality in the battery, then every time it is heated by 5°C and kept warm for 30min, observe whether the battery is abnormal. For example, continue to heat to 135°C and keep it for 30min, heat to 140°C and keep it for 30min, heat to 145°C and keep it for 30min... until the battery smokes or burns, and record this temperature, which is the thermal runaway temperature.

[0246] The above test results are shown in Table 2.

[0247] Example 2

[0248] Compared with Example 1, in the process of making the positive electrode plate, polyolefin 2 prepared in Preparation Example 2 is used to replace polyolefin 1, and its addition amount is 0.5% of the total solid weight of the positive electrode coating material, and the others are the same as in Example 1.

[0249] The test is carried out according to the test method of the battery in Example 1, and the test results are shown in Table 2.

[0250] Example 3

[0251] Compared with Example 1, in the process of making the positive electrode plate, polyolefin 3 prepared in Preparation Example 3 is used to replace polyolefin 1, and its addition amount is 2% of the total solid weight of the positive electrode coating material, and the others are the same as in Example 1.

[0252] The test is carried out according to the test method of the battery in Example 1, and the test results are shown in Table 2.

[0253] Example 4

[0254] Compared with Example 1, in the process of manufacturing the positive electrode plate, polyester 1 prepared in Preparation Example 24 was used to replace polyolefin 1, and its addition amount was 1.5% of the total solid weight of the positive electrode coating material, and the others were the same as in Example 1.

[0255] The battery was tested according to the testing method of the battery in Example 1, and the test results are shown in Table 2.

[0256] Example 5

[0257] Compared with Example 1, in the process of manufacturing the positive electrode plate, polyester 2 prepared in Preparation Example 25 was used to replace polyolefin 1, and its addition amount was 3% of the total solid weight of the positive electrode coating material, and the others were the same as in Example 1.

[0258] The battery was tested according to the testing method of the battery in Example 1, and the test results are shown in Table 2.

[0259] Example 6

[0260] Compared with Example 1, in the process of manufacturing the positive electrode plate, polyamide 1 prepared in Preparation Example 32 was used to replace polyolefin 1, and its addition amount was 0.1% of the total solid weight of the positive electrode coating material, and the others were the same as in Example 1.

[0261] The battery was tested according to the testing method of the battery in Example 1, and the test results are shown in Table 2.

[0262] Example 7

[0263] Compared with Example 1, in the process of manufacturing the positive electrode plate, polyurethane 1 prepared in Preparation Example 37 was used to replace polyolefin 1, and its addition amount was 0.8% of the total solid weight of the positive electrode coating material, and the others were the same as in Example 1.

[0264] The battery was tested according to the testing method of the battery in Example 1, and the test results are shown in Table 2.

[0265] Example 8

[0266] Compared with Example 1, in the process of manufacturing the positive electrode plate, polyimide 1 prepared in Preparation Example 38 was used to replace polyolefin 1, and its addition amount was 1% of the total solid weight of the positive electrode coating material, and the others were the same as in Example 1.

[0267] The battery was tested according to the testing method of the battery in Example 1, and the test results are shown in Table 2.

[0268] Example 9

[0269] Compared with Example 1, in the process of manufacturing the positive electrode plate, polyolefin 10 prepared in Preparation Example 10 was used to replace polyolefin 1, and its addition amount was 2% of the total solid weight of the positive electrode coating material, and the others were the same as in Example 1.

[0270] Test according to the battery testing method in Example 1, and the test results are shown in Table 2.

[0271] Example 10

[0272] Compared with Example 1, in the process of making the positive electrode plate, polyamide 2 prepared in Preparation Example 33 is used to replace polyolefin 1, and its addition amount is 4% of the total solid weight of the positive electrode coating material, and the others are the same as those in Example 1.

[0273] Test according to the battery testing method in Example 1, and the test results are shown in Table 2.

[0274] Example 11

[0275] Compared with Example 1, in the process of making the positive electrode plate, polyolefin 13 prepared in Preparation Example 13 is used to replace polyolefin 1, and its addition amount is 1% of the total solid weight of the positive electrode coating material, and the others are the same as those in Example 1.

[0276] Test according to the battery testing method in Example 1, and the test results are shown in Table 2.

[0277] Example 12

[0278] Compared with Example 1, in the process of making the positive electrode plate, polyester 3 prepared in Preparation Example 26 is used to replace polyolefin 1, and its addition amount is 2% of the total solid weight of the positive electrode coating material, and the others are the same as those in Example 1.

[0279] Test according to the battery testing method in Example 1, and the test results are shown in Table 2.

[0280] Example 13

[0281] Compared with Example 1, in the process of making the positive electrode plate, polyester 6 prepared in Preparation Example 29 is used to replace polyolefin 1, and its addition amount is 1% of the total solid weight of the positive electrode coating material, and the others are the same as those in Example 1.

[0282] Test according to the battery testing method in Example 1, and the test results are shown in Table 2.

[0283] Example 14

[0284] Compared with Example 1, in the process of making the positive electrode plate, polyolefin 11 prepared in Preparation Example 11 is used to replace polyolefin 1, and its addition amount is 0.8% of the total solid weight of the positive electrode coating material, and the others are the same as those in Example 1.

[0285] Test according to the battery testing method in Example 1, and the test results are shown in Table 2.

[0286] Example 15

[0287] Compared with Example 1, in the process of fabricating the positive electrode plate, polyester 7 prepared in Preparation Example 30 was used to replace polyolefin 1, and its addition amount was 1.2% of the total solid weight of the positive electrode coating material. Others were the same as in Example 1.

[0288] The battery was tested according to the test method of the battery in Example 1, and the test results are shown in Table 2.

[0289] Example 16

[0290] Compared with Example 1, in the process of fabricating the positive electrode plate, polyolefin 18 prepared in Preparation Example 18 was used to replace polyolefin 1, and its addition amount was 3% of the total solid weight of the positive electrode coating material. Others were the same as in Example 1.

[0291] The battery was tested according to the test method of the battery in Example 1, and the test results are shown in Table 2.

[0292] Example 17

[0293] Compared with Example 1, in the process of fabricating the positive electrode plate, polyolefin 20 prepared in Preparation Example 20 was used to replace polyolefin 1, and its addition amount was 2% of the total solid weight of the positive electrode coating material. Others were the same as in Example 1.

[0294] The battery was tested according to the test method of the battery in Example 1, and the test results are shown in Table 2.

[0295] Example 18

[0296] Compared with Example 1, in the process of fabricating the positive electrode plate, polyimide 1 prepared in Preparation Example 38 was used to replace polyolefin 1, and its addition amount was 0.05% of the total solid weight of the positive electrode coating material. Others were the same as in Example 1.

[0297] The battery was tested according to the test method of the battery in Example 1, and the test results are shown in Table 2.

[0298] Example 19

[0299] Compared with Example 1, in the process of fabricating the positive electrode plate, polyamide 2 prepared in Preparation Example 33 was used to replace polyolefin 1, and its addition amount was 6% of the total solid weight of the positive electrode coating material. Others were the same as in Example 1.

[0300] The battery was tested according to the test method of the battery in Example 1, and the test results are shown in Table 2.

[0301] Comparative Example 1

[0302] Except that polyolefin 1 was not added in the process of fabricating the positive electrode plate, others were the same as in Example 1.

[0303] The battery was tested according to the test method of the battery in Example 1, and the test results are shown in Table 2.

[0304] Comparative Example 2

[0305] Compared with Example 1, during the production process of the positive electrode plate, polyolefin 23 prepared in Preparation Example 23 was used to replace polyolefin 1, and its addition amount was 2% of the total solid weight of the positive electrode coating material. Other conditions were the same as those in Example 1.

[0306] The test was carried out according to the test method of the battery in Example 1, and the test results are shown in Table 2.

[0307] Comparative Example 3

[0308] Compared with Example 1, during the production process of the positive electrode plate, polyolefin 22 prepared in Preparation Example 22 was used to replace polyolefin 1, and its addition amount was 1% of the total solid weight of the positive electrode coating material. Other conditions were the same as those in Example 1.

[0309] The test was carried out according to the test method of the battery in Example 1, and the test results are shown in Table 2.

[0310] Comparative Example 4

[0311] Compared with Example 1, during the production process of the positive electrode plate, polyester 8 prepared in Preparation Example 31 was used to replace polyolefin 1, and its addition amount was 2% of the total solid weight of the positive electrode coating material. Other conditions were the same as those in Example 1.

[0312] The test was carried out according to the test method of the battery in Example 1, and the test results are shown in Table 2.

[0313] Table 1 Basic Parameters of Prepared Polymers

[0314]

[0315]

[0316] Note: The swelling degree of polyester 8 being "-" indicates that the polymer dissolved during the test.

[0317] Table 2 Test Results of Battery Performance

[0318]

[0319]

[0320] As can be seen from Table 1, the polymers containing coordination groups used in Examples 1-15 are selected from polymers having one of the structures of Formula 1-Formula 23. The coordination groups in the above polymers are polydentate ligands, which can have a strong coordination effect with transition metal ions in the cathode active material, and the formed protective layer is more stable. The polymers containing coordination groups used in Examples 16-17, due to the relatively large spacing of the coordination groups or steric hindrance, although they can also have a coordination effect with transition metal ions in the cathode active material, the coordination effect is weaker than that of the polymers having the structures of Formula 1-Formula 23. And at 45 °C, the swelling degree of these polymers in the electrolyte is between 5% and 50%, and the swelling loss rate is <2%.

[0321] As can be seen from Table 2, compared with Comparative Example 1 without adding the polymer containing coordination groups of the present invention, the lithium-ion batteries obtained by adding the polymer containing coordination groups in the cathode coating material in Examples 1-19 have significantly improved initial performance, high-temperature storage and cycling performance. Among them, the capacity of the lithium-ion batteries prepared in Examples 1-15 is about 3 Ah, the internal resistance is 6.8-8.9 mΩ, the thickness expansion rate during high-temperature storage is 0.2-2.2%, the capacity retention rate during high-temperature storage is 96.3-98.1%, the capacity recovery rate during high-temperature storage is 97.2-98.9%, the room-temperature cycling capacity retention rate after 1000 cycles is 92.1-93.8%, and the high-temperature cycling capacity retention rate is 88.7-90.8%. At the same time, the thermal runaway temperature in the hot box test is also 165-180 °C; while the initial performance, high-temperature storage and cycling performance of the lithium-ion batteries prepared in Examples 16-17 are inferior to those in Examples 1-15, and the thermal runaway temperature is slightly lower, at 155 °C. Compared with Example 8, only 0.05% of polyimide 1 was added to the cathode coating material in Example 18, and the high-temperature performance, cycling performance and safety performance of the lithium-ion battery prepared were all deteriorated, but were better than those of Comparative Examples 1 and 2. Compared with Example 10, 6% of polyamide 2 was added in Example 19, and the internal resistance of the battery increased significantly.

[0322] The polymer containing coordination groups of the present invention was not added to the cathode coating of Comparative Example 1. The lithium-ion battery prepared had good initial performance, but poor high-temperature storage and cycling performance. The capacity retention rate was <80% after 1000 high-temperature cycles, and the thermal runaway temperature was 140 °C.

[0323] In Comparative Example 2, polyolefin 23 with a swelling degree of only 2% was added, resulting in a significant increase in the internal resistance of the battery and a low capacity. The capacity decayed to less than 80% after 1000 room-temperature cycles.

[0324] In Comparative Example 3, polyolefin 22 with a swelling degree of 86% was added, and in Comparative Example 4, polyester 8 that could dissolve in the electrolyte was added. The capacities of both groups of batteries were low. Their high-temperature storage and cycling performance were slightly better than those of Comparative Example 1, but significantly lower than those of Examples 1-17, and the thermal runaway temperature did not increase at all.

[0325] In summary, in the present invention, a polymer containing a coordination group is added to the positive electrode. The coordination group contained in the polymer coordinates with the transition metal ions of the positive electrode active material, enabling the polymer to be adsorbed on the surface of the positive electrode active material. At the same time, after contacting the electrolyte, the polymer can absorb the electrolyte and undergo a low degree of swelling, thereby forming a complete and stable polymer coating layer with a certain ion-conducting effect on the surface of the positive electrode active material, which can more effectively inhibit the decomposition reaction of the electrolyte on the surface of the positive electrode active material. This technology can follow the traditional production process, avoiding the problems of complex process and incomplete coating caused by separately performing inorganic coating on the positive electrode active material in the prior art, and can meet the requirements of high-energy-density and high-safety batteries. At the same time, this technology can also inhibit the oxidative decomposition reaction of the electrolyte on the surface of the positive electrode active material and the dissolution of transition metal ions, thereby greatly improving the high-temperature performance of lithium-ion batteries and improving the safety of lithium-ion batteries, and having great application prospects.

[0326] In addition, the polymer containing a coordination group of the present invention is also applicable to sodium-ion batteries. The coordination group contained in the polymer coordinates with the transition metal ions of the positive electrode active material of the sodium-ion battery, enabling the polymer to be adsorbed on the surface of the positive electrode active material. At the same time, after contacting the electrolyte, the polymer can absorb the electrolyte and undergo a low degree of swelling, thereby forming a complete and stable polymer coating layer with a certain ion-conducting effect on the surface of the positive electrode active material, which can more effectively inhibit the decomposition reaction of the electrolyte on the surface of the positive electrode active material, and ultimately improve the high-temperature performance of sodium-ion batteries and improve the safety of sodium-ion batteries.

[0327] Although this application is disclosed above with preferred embodiments, it is not used to limit the claims. Any person skilled in the art can make several possible changes and modifications without departing from the concept of this application. Therefore, the protection scope of this application should be determined by the scope defined by the claims of this application. The above are only preferred embodiments of the implementation of the present invention, and do not constitute any form of limitation to the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention need to be included within the protection scope of the present invention.

Claims

1. A lithium-ion battery or a sodium-ion battery, characterized in that, It includes a positive electrode, a negative electrode, a separator, and an electrolyte. The positive electrode includes a current collector and a positive electrode coating material loaded on the current collector. The positive electrode coating material includes a positive electrode active material containing a transition metal and a polymer containing a coordination group. The coordination group can coordinate with the transition metal ions in the positive electrode active material, and at 25-60 °C, the swelling degree of the polymer containing the coordination group in the electrolyte is 5-50%, and the swelling loss rate < 2%; the swelling degree refers to the ratio of the mass difference of the polymer containing the coordination group before and after soaking in the electrolyte to the mass of the polymer before soaking; the swelling loss rate refers to the ratio of the mass lost due to partial dissolution of the polymer into the electrolyte when the polymer containing the coordination group swells in the electrolyte to the mass of the polymer before swelling. Among them, the coordination group contains one or more of cyano, carbonyl, pyridyl, pyrazinyl, pyrimidinyl, furyl, pyrrolyl, thienyl, thiazolyl, and oxazolyl.

2. The lithium-ion battery or sodium-ion battery according to claim 1, characterized in that, The coordination group contains two or more atoms that can coordinate with the same transition metal ion.

3. The lithium ion battery or sodium ion battery according to claim 1, characterized in that, The coordination group includes one or more of the following structures wherein, R1 is selected from one of hydrogen, hydrocarbon group, halogenated hydrocarbon group, oxygen-containing substituted hydrocarbon group, nitrogen-containing substituted hydrocarbon group, phosphorus-containing substituted hydrocarbon group, or sulfur-containing substituted hydrocarbon group, and R2 and R4 are each independently selected from one of hydrocarbon group, halogenated hydrocarbon group, oxygen-containing substituted hydrocarbon group, nitrogen-containing substituted hydrocarbon group, phosphorus-containing substituted hydrocarbon group, or sulfur-containing substituted hydrocarbon group, R3 is selected from one of hydrogen, hydrocarbon group, halogenated hydrocarbon group, oxygen-containing substituted hydrocarbon group, nitrogen-containing substituted hydrocarbon group, phosphorus-containing substituted hydrocarbon group, or sulfur-containing substituted hydrocarbon group, X1 is selected from S, NH, or O, and X2 is selected from S or O.

4. The lithium-ion battery or sodium-ion battery according to claim 2, wherein The coordination group includes one or more of the following structures wherein, R1 is selected from one of hydrogen, hydrocarbon group, halogenated hydrocarbon group, oxygen-containing substituted hydrocarbon group, nitrogen-containing substituted hydrocarbon group, phosphorus-containing substituted hydrocarbon group, or sulfur-containing substituted hydrocarbon group, and R2 and R4 are each independently selected from one of hydrocarbon group, halogenated hydrocarbon group, oxygen-containing substituted hydrocarbon group, nitrogen-containing substituted hydrocarbon group, phosphorus-containing substituted hydrocarbon group, or sulfur-containing substituted hydrocarbon group, R3 is selected from one of hydrogen, hydrocarbon group, halogenated hydrocarbon group, oxygen-containing substituted hydrocarbon group, nitrogen-containing substituted hydrocarbon group, phosphorus-containing substituted hydrocarbon group, or sulfur-containing substituted hydrocarbon group, X1 is selected from S, NH, or O, and X2 is selected from S or O.

5. The lithium-ion battery or sodium-ion battery according to claim 1, characterized in that, The polymer containing the coordination group is selected from one or more of polyolefin, polyester, polyamide, polyurethane, and polyimide.

6. The lithium-ion battery or sodium-ion battery according to claim 2, characterized in that, The polymer containing the coordination group is selected from one or more of polyolefin, polyester, polyamide, polyurethane, and polyimide.

7. The lithium ion battery or sodium ion battery according to claim 3, characterized in that, The polymer containing the coordination group is selected from one or more of polyolefin, polyester, polyamide, polyurethane, and polyimide.

8. The lithium ion battery or sodium ion battery according to claim 4, characterized in that, The polymer containing the coordination group is selected from one or more of polyolefin, polyester, polyamide, polyurethane, and polyimide.

9. The lithium ion battery or sodium ion battery according to claim 1, characterized in that, Based on the total weight of the solid matter of the positive electrode coating material loaded on the current collector, the content of the polymer containing the coordination group is 0.1-10%.

10. The lithium ion battery or sodium ion battery according to claim 9, characterized in that, The content of the polymer containing the coordination group is 0.2-5%.

11. The lithium-ion battery or sodium-ion battery according to claim 9, wherein, The content of the polymer containing the coordination group is 0.2-2%.

12. The lithium-ion battery or sodium-ion battery according to claim 9, characterized in that, The content of the polymer containing a coordination group is 0.5-2%.

13. The lithium ion battery or sodium ion battery according to claim 2, characterized in that, Based on the total weight of the solid of the positive electrode coating material loaded on the current collector, the content of the polymer containing a coordination group is 0.1-10%.

14. The lithium-ion battery or sodium-ion battery according to claim 3, wherein Based on the total weight of the solid of the positive electrode coating material loaded on the current collector, the content of the polymer containing a coordination group is 0.1-10%.

15. The lithium-ion battery or sodium-ion battery according to claim 1, characterized in that, The transition metal is selected from one or more of nickel, cobalt, manganese, copper and iron.

16. The lithium-ion battery or sodium-ion battery according to claim 2, characterized in that, The transition metal is selected from one or more of nickel, cobalt, manganese, copper and iron.

17. The lithium ion battery or sodium ion battery according to claim 3, characterized in that, The transition metal is selected from one or more of nickel, cobalt, manganese, copper and iron.

18. The lithium ion battery or sodium ion battery according to claim 5, characterized in that, The transition metal is selected from one or more of nickel, cobalt, manganese, copper and iron.

19. The lithium-ion battery or sodium-ion battery according to claim 9, wherein The transition metal is selected from one or more of nickel, cobalt, manganese, copper and iron.

20. The lithium-ion battery or sodium-ion battery according to any one of claims 1-19, characterized in that, The electrolyte includes an organic solvent.

21. The lithium-ion battery or sodium-ion battery according to claim 20, characterized in that, The organic solvent is selected from one or more of ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate and propyl propionate.

22. The lithium ion battery or sodium ion battery according to claim 20, wherein In the lithium ion battery, the electrolyte further includes a lithium salt, and the lithium salt is selected from one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis(trifluoromethylsulfonyl)imide and lithium bisfluorosulfonylimide; or, In the sodium ion battery, the electrolyte further includes a sodium salt, and the sodium salt is selected from one or more of sodium hexafluorophosphate, sodium tetrafluoroborate, sodium bis(trifluoromethylsulfonyl)imide and sodium bisfluorosulfonylimide.

23. The lithium ion battery or sodium ion battery according to claim 20, characterized in that, The electrolyte further includes one or more of an unsaturated cyclic carbonate, a fluorinated cyclic carbonate, a cyclic sultone and a cyclic sulfate.

24. The lithium ion battery or sodium ion battery according to claim 23, wherein The unsaturated cyclic carbonate is selected from vinylene carbonate and / or ethyl vinyl carbonate, and / or the fluorinated cyclic carbonate is selected from at least one of fluoroethylene carbonate, trifluoromethyl ethylene carbonate or difluoroethylene carbonate, and / or the cyclic sultone is selected from at least one of 1,3-propane sultone, 1,4-butane sultone and allyl-1,3-sultone, and / or the cyclic sulfate is selected from at least one of ethylene sulfate, propylene sulfate and 4-methyl ethylene sulfate.

25. The lithium ion battery or sodium ion battery according to claim 22, characterized in that, The electrolyte further includes one or more of an unsaturated cyclic carbonate, a fluorinated cyclic carbonate, a cyclic sultone and a cyclic sulfate.

26. The method for preparing a lithium-ion battery or a sodium-ion battery according to any one of claims 1-25, characterized in that, The preparation method includes forming a battery cell with a positive electrode, a negative electrode and a separator and then placing it in a battery case, and then injecting an electrolyte to obtain a semi-finished lithium ion battery or a semi-finished sodium ion battery. The semi-finished lithium ion battery or the semi-finished sodium ion battery is formed and exhausted, and then the liquid injection port of the battery case is sealed to obtain a lithium ion battery or a sodium ion battery. Among them, the positive electrode is obtained by coating a positive electrode coating material on a current collector and then drying, rolling and slitting. The positive electrode coating material is prepared by mixing the polymer containing a coordination group with a solvent and then mixing it with a positive electrode active material, a conductive agent and a binder.

27. A positive electrode coating material, which comprises a positive electrode active material containing a transition metal and a polymer containing a coordination group; the coordination group can coordinate with the transition metal ions in the positive electrode active material, and at 25-60 °C, the swelling degree of the polymer containing a coordination group in the electrolyte is 5-50%, and the swelling loss rate < 2%; the swelling degree refers to the ratio of the mass difference of the polymer containing a coordination group before and after immersion in the electrolyte to the mass of the polymer before immersion; the swelling loss rate refers to the ratio of the mass lost due to partial dissolution of the polymer into the electrolyte during the swelling of the polymer containing a coordination group in the electrolyte to the mass of the polymer before swelling; Among them, the coordination group contains one or more of a cyano group, a carbonyl group, a pyridyl group, a pyrazinyl group, a pyrimidinyl group, a furyl group, a pyrrolyl group, a thienyl group, a thiazolyl group and an oxazolyl group.

28. The positive electrode coating material according to claim 27, wherein The positive electrode coating material further contains a conductive agent and a binder.

29. A method for preparing the positive electrode coating material according to claim 27 or 28, which comprises mixing the polymer containing a coordination group with a solvent and then mixing it with a positive electrode active material, a conductive agent and a binder.

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