Electrolyte and battery

Abstract

Provided in the present application are an electrolyte and a battery. The electrolyte is used for a battery comprising a lithium supplementing additive, and the lithium supplementing additive is a lithium supplementing additive capable of decomposing to generate oxygen. The electrolyte includes an additive shown in Formula 1. In Formula 1, R1, R2, R3, and R4 are each independently selected from a C1-C5 alkyl group, a C2-C5 alkenyl group, a C2-C5 alkynyl group, a C6-C12 aryl group, a C3-C6 unsaturated cyclic hydrocarbyl group unsubstituted or substituted with Ra, a C1-C6 alkoxy group unsubstituted or substituted with Ra, a C2-C6 alkenyloxy group unsubstituted or substituted with Ra, a C2-C6 alkynyloxy group unsubstituted or substituted with Ra, a C6-C12 aryloxy group unsubstituted or substituted with Ra, and a heteroatom. At least one of R1, R2, R3, and R4 contains an unsaturated bond. The substituent Ra is selected from a C1-C5 alkyl group or a halogen atom. The present application can reduce the expansion rate of a battery, inhibit lithium plating, reduce impedance, and improve the high-temperature cycle performance and storage performance of the battery.

Description

An electrolyte and a battery

[0001] This application claims priority to Chinese Patent Application No. 202410971743.7, filed on July 19, 2024, entitled "An Electrolyte and a Battery", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to an electrolyte and a battery, belonging to the field of lithium-ion battery technology. Background Technology

[0003] The current short cycle life of lithium-ion batteries affects their service life, hindering the large-scale commercial application of energy storage power stations and increasing battery recycling costs, which in turn increases production costs. Therefore, how to further improve the cycle life of lithium-ion batteries is an urgent problem to be solved in the energy storage field.

[0004] The loss of active lithium ions is the direct cause of cycle degradation and shortened cycle life in lithium-ion batteries. This loss includes: during the initial charge-discharge cycle, a solid electrolyte interphase (SEI) film forms on the negative electrode surface. The formation of the SEI film consumes a significant amount of active lithium ions, leading to a low coulombic efficiency in the first cycle. Additionally, during the charge-discharge cycle, the cracking and fragmentation of the positive electrode active material particles, as well as the thickening and repair of the SEI film, all consume active lithium ions. As active lithium ions are continuously lost, lithium-ion batteries experience cycle degradation, a significant decrease in cycle performance, and a shortened cycle life.

[0005] Adding lithium additives can improve the cycle life of lithium-ion batteries. Among these, positive electrode lithium addition is relatively simple to perform and has the greatest industrial application potential due to its high safety and the fact that it does not require changes to existing battery manufacturing processes. A typical positive electrode lithium addition involves adding a small amount of high-capacity material during the positive electrode slurry preparation process. During charging, Li... + The lithium replenisher is extracted from high-capacity materials to compensate for the irreversible capacity loss during the first charge and discharge cycle. This high-capacity material is the lithium replenisher. While it can replenish lithium, due to factors such as the reactivity of the lithium replenisher (e.g., lithium iron ferrite Li5FeO4), oxygen is generated during battery charge-discharge cycles or high-temperature storage. Oxygen can cause battery expansion and adversely affect the process of active lithium intercalation into the negative electrode, leading to problems such as black spots and lithium plating, resulting in a decline in high-temperature performance and cycle performance. Summary of the Invention

[0006] This application provides an electrolyte and a battery that can improve the battery's expansion problem, suppress lithium plating, reduce interface impedance, and thus significantly improve the battery's high-temperature cycle performance and storage performance.

[0007] This application provides an electrolyte for use in a battery containing a lithium replenishing agent, wherein the lithium replenishing agent is a lithium replenishing agent that can decompose to generate oxygen; the electrolyte includes additives shown in Formula 1.

[0008] In Formula 1, R1, R2, R3, and R4 are each independently selected from C1-C5 alkyl, C2-C5 alkenyl, C2-C5 alkynyl, C6-C12 aryl, unsubstituted or R-substituted groups. a Substituted C3–C6 unsaturated cyclic hydrocarbon groups, unsubstituted or R a Substituted C1–C6 alkoxy groups, unsubstituted or R a Substituted C2–C6 olefins, unsubstituted or R a Substituted C2–C6 alkynyl groups, unsubstituted or R a The substituted C6-C12 aromatic phenolic oxygen group and heteroatom, at least one of R1, R2, R3, and R4 contains an unsaturated bond; the substituent R a Alkyl or halogen atoms selected from C1 to C5.

[0009] In one embodiment of this application, the heteroatom is selected from N, O, S, and Si.

[0010] In one embodiment of this application, R1 is selected from C1-C5 alkyl or C2-C5 alkenyl groups, R2 and R3 are each independently selected from C1-C5 alkyl, C2-C5 alkenyl, or C6-C12 aryl groups, and R4 is selected from unsubstituted or R-substituted groups. a The substituted C2-C6 alkenyl group; or, R1 and R2 are each independently selected from C2-C5 alkenyl groups, R3 is selected from C1-C5 alkyl groups or C6-C12 aryl groups, and R4 is selected from unsubstituted or R-substituted groups. a The substituted C1-C6 alkoxy group; or, R1 is selected from C2-C5 alkenyl groups, R2 is selected from C2-C5 alkenyl or C2-C5 alkynyl groups, R3 is selected from C1-C5 alkyl or C2-C5 alkenyl groups, and R4 is selected from C1-C5 alkyl groups; or, R1 is selected from C1-C5 alkyl groups, R3 is selected from C1-C5 alkyl or C2-C5 alkenyl groups, and R4 is selected from unsubstituted or R-substituted groups. a The substituted C1-C5 alkoxy or C2-C5 alkenyl group, wherein R2 is selected from the group shown in formula a.

[0011] In equation a, R 11 Selected from N, O, C2-C5 alkenyl groups or *-OR 12 -O-*, where R 12Selected from C1 to C5 alkyl groups, R 13 R 14 R 15 Each is independently selected from C1 to C5 alkyl groups, unsubstituted or R-substituted. b Substituted C1–C5 alkoxy or C2–C5 alkenyl groups; substituent R b The R1, R2, and R3 are each independently selected from unsubstituted or R-substituted alkyl or halogen atoms selected from C1 to C5. c The substituted C1-C6 alkoxy group, wherein R4 is selected from the group shown in formula b; the substituent R c Selected from C1 to C5 alkyl or halogen atoms;

[0012] In one embodiment of this application, the additive represented by Formula 1 is selected from compounds represented by Formulas 1-1 to 1-12:

[0013] In one embodiment of this application, the additive has a mass percentage content of 0.2% to 2% in the electrolyte.

[0014] In one embodiment of this application, the lithium supplement includes one or more of lithium nickelate, lithium ferrite, and lithium oxide.

[0015] In one embodiment of this application, the mass ratio of the additive to the lithium supplement is 1:(4-32).

[0016] In one embodiment of this application, the electrolyte further includes a film-forming agent, which includes one or more of cyclic carbonates, cyclic sulfates, and cyclic sulfonyl lactones.

[0017] In one embodiment of this application, the film-forming agent has a mass percentage content of 0.5% to 3% in the electrolyte, preferably 0.5% to 2.5%; and / or, the cyclic carbonate includes vinylene carbonate and / or fluoroethylene carbonate; and / or, the cyclic sulfate includes vinyl sulfate; and / or, the cyclic sulfonyl lactone includes 1,3-propanesulfonyl lactone.

[0018] In one embodiment of this application, the electrolyte further includes an organic solvent and an electrolyte salt. The organic solvent includes one or more of carbonate solvents, carboxylic acid ester solvents, and ether solvents. The carbonate solvent includes one or more of ethylene carbonate, propylene carbonate, butene carbonate, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methyl ethyl carbonate, and methyl propyl carbonate. The carboxylic acid ester solvent includes one or more of methyl formate, methyl acetate, methyl propionate, methyl butyrate, ethyl acetate, ethyl propionate, propyl propionate, and ethyl butyrate. The ether solvent includes one or more of tetrahydrofuran, 1,3-dioxapentane, diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether. The electrolyte salt includes one or more of lithium hexafluorophosphate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, and lithium tetrafluoroborate. The electrolyte salt has a mass percentage of 8% to 18% in the electrolyte.

[0019] This application also provides a battery, including a positive electrode sheet containing a lithium replenishing agent and an electrolyte as described above; the positive electrode sheet includes a positive current collector and a positive active material layer located on at least one side surface of the positive current collector, the positive active material layer including the lithium replenishing agent, the positive active material layer further including a positive active material, the positive active material including one or more of nickel-cobalt-manganese ternary materials, nickel-cobalt-aluminum ternary materials, nickel-cobalt-manganese-aluminum quaternary materials, nickel-manganese-aluminum ternary materials, lithium cobalt oxide, lithium manganese oxide, lithium manganese iron phosphate, and lithium iron phosphate; and / or, the battery further includes a negative electrode sheet, the negative electrode sheet including a negative current collector and a negative active material layer located on at least one side surface of the negative current collector, the negative active material layer including a negative active material, the negative active material including a carbon-based material and / or a silicon-based material, the carbon-based material including one or more of natural graphite, artificial graphite, hard carbon, and soft carbon, the silicon-based material including one or more of pure silicon material, silicon-carbon material, and silicon-oxygen material.

[0020] In one embodiment of this application, the lithium supplement includes one or more of lithium nickelate, lithium ferrite, and lithium oxide.

[0021] In one embodiment of this application, the mass ratio of the additive to the lithium supplement is 1:(4-32).

[0022] This application provides an electrolyte and a battery. The electrolyte is used in a battery containing a lithium replenishing agent, which is a lithium replenishing agent that can decompose to generate oxygen. The lithium replenishing agent can effectively compensate for the loss of active lithium ions by releasing active lithium. The electrolyte includes an additive shown in Formula 1. The additive can absorb oxygen generated during battery cycling and high-temperature storage due to factors such as the reactivity of the lithium replenishing agent itself, effectively mitigating battery swelling and lithium plating problems caused by oxygen, reducing impedance, and thus significantly improving the high-temperature cycling performance and storage performance of the battery. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. All other embodiments obtained by those skilled in the art based on this application are within the scope of protection of this application.

[0024] This application provides an electrolyte for use in a battery containing a lithium replenishing agent, wherein the lithium replenishing agent is a lithium replenishing agent that can decompose to generate oxygen; the electrolyte includes additives shown in Formula 1.

[0025] In Formula 1, R1, R2, R3, and R4 are each independently selected from C1-C5 alkyl, C2-C5 alkenyl, C2-C5 alkynyl, C6-C12 aryl, unsubstituted or R-substituted groups. a Substituted C3–C6 unsaturated cyclic hydrocarbon groups, unsubstituted or R a Substituted C1–C6 alkoxy groups, unsubstituted or R a Substituted C2–C6 olefins, unsubstituted or R a Substituted C2–C6 alkynyl groups, unsubstituted or R a The substituted C6-C12 aromatic phenolic oxygen group and heteroatom, at least one of R1, R2, R3, and R4 contains an unsaturated bond; the substituent R a Alkyl or halogen atoms selected from C1 to C5.

[0026] According to the inventors' research and analysis, lithium replenishing agents can replenish lithium, but due to factors such as the reactivity of the lithium replenishing agents themselves, oxygen will be generated during battery charge-discharge cycles or high-temperature storage. In the battery system described above, additives (siloxanes or silanes) with the structure shown in Formula 1 can exhibit strong oxygen absorption capacity, absorbing the oxygen generated due to factors such as the reactivity of the lithium replenishing agents themselves, forming a dense silicon-containing polyalkoxy network channel, avoiding oxygen accumulation inside the battery, thereby improving the battery expansion problem. At the same time, the formed dense silicon-containing polyalkoxy network channel can guide the active lithium to desolvate and embed into the negative electrode, reducing polarization, thereby suppressing lithium plating problems, reducing interface impedance, and improving the high-temperature cycle performance and storage performance of the battery.

[0027] Therefore, the embodiments of this application effectively compensate for the loss of active lithium ions by using lithium replenishment agents, and at the same time, the additives shown in Formula 1 can improve the battery expansion problem, suppress lithium plating, reduce interface impedance, and thus significantly improve the high-temperature cycle performance and storage performance of the battery.

[0028] For example, the number of carbon atoms in the C1-C5 alkyl group can be 1, 2, 3, 4 or 5; the number of carbon atoms in the C2-C5 alkenyl group can also be 2, 3, 4 or 5; the number of carbon atoms in the C2-C5 alkynyl group can also be 2, 3, 4 or 5; and the C6-C12 aromatic group can include phenyl.

[0029] The substituents in the above-mentioned substituted C3-C6 unsaturated cyclic hydrocarbon groups, substituted C1-C6 alkoxy groups, substituted C2-C6 alkenoxy groups, substituted C2-C6 alkynoxy groups, and substituted C6-C12 aromatic phenoloxy groups may contain heteroatoms.

[0030] The heteroatoms mentioned above are selected from N, O, S, and Si.

[0031] In some embodiments, R1 is selected from C1-C5 alkyl or C2-C5 alkenyl groups, R2 and R3 are each independently selected from C2-C5 alkyl, C2-C5 alkenyl, or C6-C12 aryl groups, and R4 is selected from unsubstituted or R-substituted groups. a The addition of substituted C2-C6 olefins enhances oxygen absorption, thus improving battery swelling and lithium plating, reducing impedance, and significantly improving high-temperature cycle performance and storage performance.

[0032] In some embodiments, R1 and R2 are each independently selected from C2-C5 alkenyl groups, R3 is selected from C1-C5 alkyl groups or C6-C12 aryl groups, and R4 is selected from unsubstituted or R-substituted groups. a The substitution of C1 to C6 alkoxy groups in the additive shown in Formula 1 results in a denser silicon-containing polyalkoxy network channel, which is more conducive to lithium ion desolvation, facilitating its insertion into the negative electrode and reducing polarization.

[0033] In some embodiments, R1 is selected from C2-C5 alkenyl groups, R2 is selected from C2-C5 alkenyl groups or C2-C5 alkynyl groups, R3 is selected from C1-C5 alkyl groups or C2-C5 alkenyl groups, and R4 is selected from C1-C5 alkyl groups. This additive has a higher oxygen absorption capacity, which better improves the battery's expansion and lithium plating problems, reduces impedance, and significantly improves the battery's high-temperature cycle performance and storage performance.

[0034] In some embodiments, R1 is selected from C1-C5 alkyl groups, R3 is selected from C1-C5 alkyl groups or C2-C5 alkenyl groups, and R4 is selected from unsubstituted or R-substituted groups. a The substituted C1-C5 alkoxy or C2-C5 alkenyl group, where R2 is selected from the group shown in formula a.

[0035] In equation a, R 11 Selected from N, O, C2-C5 alkenyl groups or *-OR 12 -O-*, where R 12 Selected from C1 to C5 alkyl groups, R 13 R 14 R 15 Each is independently selected from C1 to C5 alkyl groups, unsubstituted or R-substituted. b Substituted C1–C5 alkoxy or C2–C5 alkenyl groups; substituent R b The silicon content is selected from alkyl or halogen atoms from C1 to C5. Because a low silicon content in the silicon-containing polyalkoxy network channel (silicon-containing polyalkoxy membrane) increases the membrane thickness and decreases the hardness, introducing the group shown in formula a forms structures such as silicon-oxy-silicon in the silicon-containing polyalkoxy network channel (silicon-containing polyalkoxy membrane). This results in a higher silicon content in the silicon-containing polyalkoxy network channel, forming a membrane with a more suitable thickness and hardness. This allows for better guidance of active lithium desolvation and insertion into the negative electrode, reducing polarization, thereby suppressing lithium plating, lowering interfacial impedance, and improving the high-temperature cycle performance and storage performance of the battery.

[0036] In some embodiments, R1, R2, and R3 are each independently selected from those that are not substituted or replaced by R. c The substituted C1-C6 alkoxy group, R4 is selected from the group shown in formula b; the substituent R c Selected from C1 to C5 alkyl or halogen atoms;

[0037] The chain segment shown in Formula b has a better oxygen absorption effect. By introducing the chain segment shown in Formula b, the oxygen absorption capacity of the additive shown in Formula 1 is further improved, avoiding the accumulation of oxygen inside the battery, thereby better improving the battery expansion problem. It also makes the silicon-containing polyalkoxy network channel (silicon-containing polyalkoxy film) more flexible and has better self-healing ability, reducing the loss of silicon-containing polyalkoxy film during electrode expansion.

[0038] In some embodiments, the additive shown in Formula 1 is selected from the compounds shown in Formulas 1-1 to 1-12:

[0039] In some embodiments, the lithium replenishing agent includes lithium replenishing materials containing oxygen, specifically one or more of lithium nickelate, lithium iron ferrite, and lithium oxide. These lithium replenishing agents can efficiently compensate for the loss of active lithium by releasing active lithium. For example, lithium iron ferrite has the advantages of high irreversible capacity (≥670mAh), good cycle improvement effect (energy density improvement of 6%-8%), and low production cost. In addition, it has high chemical reactivity and can achieve the effect of lithium replenishment by efficiently releasing active lithium, which helps to improve the cycle performance of the battery.

[0040] However, during battery charge-discharge cycles, these oxygen-containing lithium replenishment materials release active lithium along with oxygen, which causes battery expansion and adversely affects the process of active lithium intercalation into the negative electrode, leading to problems such as black spots and lithium plating. Furthermore, during battery storage (especially high-temperature storage), these oxygen-containing lithium replenishment materials continue to react and generate oxygen, further exacerbating battery expansion and lithium plating, thus degrading the battery's high-temperature cycle performance and storage performance. In the aforementioned battery system, additives (siloxanes or silanes) with the structure shown in Formula 1 exhibit strong oxygen absorption capabilities. They absorb oxygen generated by factors such as the reactivity of the lithium replenishment agent itself, forming a dense silicon-containing polyalkoxy network channel. This prevents oxygen accumulation inside the battery, thereby improving the expansion problem. Simultaneously, the formed dense silicon-containing polyalkoxy network channel guides the desolvation and intercalation of active lithium into the negative electrode, reducing polarization, thus suppressing lithium plating, lowering interfacial impedance, and improving the battery's high-temperature cycle performance and storage performance.

[0041] The mass ratio of the additive to the lithium replenisher can be 1:(4-32), for example, 1:4, 1:8, 1:16, 1:32, or any combination thereof. This is beneficial for fully absorbing the generated oxygen while compensating for the loss of active lithium, thereby improving battery expansion and lithium plating problems, reducing impedance, and improving the battery's high-temperature cycle performance and storage performance. The reason for this is that if the amount of additive is too high, the lithium ion insertion / extraction channels formed by the silicon polyalkoxide film become too saturated, the channel size shrinks, and the film thickness increases, which is not conducive to the smooth insertion / extraction of active lithium and degrades the effect of inhibiting lithium plating. On the other hand, if the amount of additive is too low, it is insufficient to absorb the oxygen generated by factors such as the reactivity of the lithium replenisher itself, resulting in poor effect of inhibiting battery expansion. By controlling the mass ratio of the additive to the lithium replenisher to be 1:(4-32), it is beneficial to absorb oxygen more fully while keeping the amount of additive less and reducing costs.

[0042] The above-mentioned additives can be present in the electrolyte at a mass percentage of 0.2%-2%, which is beneficial for sufficient oxygen absorption without causing excessive SEI film thickness and increased impedance, thus avoiding battery capacity decay. In some embodiments, the electrolyte also includes a film-forming agent, which includes one or more of cyclic carbonates, cyclic sulfates, and cyclic sulfonyl lactones. The film-forming agent and the above-mentioned additives have a synergistic effect, helping to improve battery swelling and lithium plating problems, reduce impedance, and thus further improve the high-temperature cycle performance and storage performance of the battery. The reason for this is that the film formed by the film-forming agent alone is thicker and looser, and its effect on guiding the desolvation and insertion of active lithium into the negative electrode is poor. However, the additive shown in Formula 1 absorbs oxygen and forms a dense SEI film containing silicon-modified polyether. This SEI film is thinner and denser, and its effect on guiding the desolvation and insertion of active lithium into the negative electrode is better.

[0043] In some embodiments, the cyclic carbonates described above include vinylene carbonate and / or fluoroethylene carbonate.

[0044] In some embodiments, the cyclic sulfate esters described above may include vinyl sulfate esters.

[0045] In some embodiments, the cyclic sulfonate lactones described above may include 1,3-propanesulfonate lactones.

[0046] Furthermore, when the mass percentage of the film-forming agent in the electrolyte is 0.5% to 3%, for example, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, or any combination thereof, preferably 0.5% to 2.5%, the synergistic effect of the film-forming agent and the additive is better, which more effectively improves the battery swelling and lithium plating problems, reduces impedance, and is more conducive to improving the high-temperature cycle performance and storage performance of the battery. The reason for this is that if the amount of film-forming agent is too low, a high-quality SEI film cannot be formed on the surface of the negative electrode, so the negative electrode cannot be well protected; if the amount of film-forming agent is too high, the thickness of the SEI film formed on the surface of the negative electrode will be too large, thus increasing the internal resistance and reducing the effect of guiding lithium ions to intercalate into the negative electrode, increasing polarization, leading to easy lithium plating problems and causing battery capacity decay.

[0047] In some embodiments, the electrolyte may also include an organic solvent and an electrolyte salt.

[0048] Organic solvents may include one or more of carbonate solvents, carboxylic acid ester solvents, and ether solvents. Specifically, carbonate solvents may include one or more of ethylene carbonate, propylene carbonate, butene carbonate, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methyl ethyl carbonate, and methyl propyl carbonate. Carboxylic acid ester solvents may include one or more of methyl formate, methyl acetate, methyl propionate, methyl butyrate, ethyl acetate, ethyl propionate, propyl propionate, and ethyl butyrate. Ether solvents may include one or more of tetrahydrofuran, 1,3-dioxane, diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether.

[0049] In some embodiments, the organic solvents mentioned above include ethylene carbonate (EC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC), which helps the additives to better absorb oxygen, improve battery swelling and lithium plating, reduce impedance, and improve the battery's high-temperature cycle performance and storage performance.

[0050] The mass ratio of EC, DMC and EMC is (2-4):(0.5-2):(5-7), for example, 2:0.5:5, 3:1:6, 4:2:7 or any combination thereof.

[0051] Electrolyte salts include one or more of lithium hexafluorophosphate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, and lithium tetrafluoroborate.

[0052] Furthermore, the mass percentage of the electrolyte salt in the electrolyte is 8% to 18%, for example, a range consisting of 8%, 10%, 12%, 12.5%, 14%, 16%, 18%, or any two of these.

[0053] The electrolyte in this application is prepared by the following process: adding an electrolyte salt to an organic solvent to obtain a mixed solution, then adding an additive to the mixed solution and mixing it evenly to obtain the electrolyte.

[0054] Since electrolyte salts generate heat during dissolution, which raises the temperature of the mixed solution, the process of adding additives to the mixed solution may include: adding additives after cooling the mixed solution to room temperature.

[0055] In practice, the electrolyte can be prepared in a glove box.

[0056] This application also provides a battery, including a positive electrode sheet containing a lithium replenishing agent and the aforementioned electrolyte; the positive electrode sheet includes a positive current collector and a positive active material layer located on at least one side surface of the positive current collector, the positive active material layer including the aforementioned lithium replenishing agent; the positive active material layer further includes a positive active material, which includes one or more of the following: nickel-cobalt-manganese ternary material, nickel-cobalt-aluminum ternary material, nickel-cobalt-manganese-aluminum quaternary material, nickel-manganese-aluminum ternary material, lithium cobalt oxide, lithium manganese oxide, lithium manganese iron phosphate, and lithium iron phosphate. This application embodiment can compensate for the loss of active lithium ions generated by the aforementioned positive active material during battery cycling, and can absorb oxygen released by the positive active material while absorbing oxygen released by the lithium replenishing agent, thereby improving the battery's expansion and lithium plating problems, reducing impedance, and significantly improving the battery's high-temperature cycle performance and storage performance.

[0057] In some embodiments, the lithium replenishing agent includes lithium replenishing materials containing oxygen, specifically one or more of lithium nickelate, lithium iron ferrite, and lithium oxide. These lithium replenishing agents can efficiently compensate for the loss of active lithium by releasing active lithium. For example, lithium iron ferrite has the advantages of high irreversible capacity (≥670mAh), good cycle improvement effect (energy density improvement of 6%-8%), and low production cost. In addition, it has high chemical reactivity and can achieve the effect of lithium replenishment by efficiently releasing active lithium, which helps to improve the cycle performance of the battery.

[0058] However, during battery charge-discharge cycles, these oxygen-containing lithium replenishment materials release active lithium along with oxygen, which causes battery expansion and adversely affects the process of active lithium intercalation into the negative electrode, leading to problems such as black spots and lithium plating. Furthermore, during battery storage (especially high-temperature storage), these oxygen-containing lithium replenishment materials continue to react and generate oxygen, further exacerbating battery expansion and lithium plating, thus degrading the battery's high-temperature cycle performance and storage performance. In the aforementioned battery system, additives (siloxanes or silanes) with the structure shown in Formula 1 exhibit strong oxygen absorption capabilities. They absorb oxygen generated by factors such as the reactivity of the lithium replenishment agent itself, forming a dense silicon-containing polyalkoxy network channel. This prevents oxygen accumulation inside the battery, thereby improving the expansion problem. Simultaneously, the formed dense silicon-containing polyalkoxy network channel guides the desolvation and intercalation of active lithium into the negative electrode, reducing polarization, thus suppressing lithium plating, lowering interfacial impedance, and improving the battery's high-temperature cycle performance and storage performance.

[0059] The mass ratio of the additive to the lithium replenisher can be 1:(4-32), for example, 1:4, 1:8, 1:16, 1:32, or any combination thereof. This is beneficial for fully absorbing the generated oxygen while compensating for the loss of active lithium, thereby improving battery expansion and lithium plating problems, reducing impedance, and improving the battery's high-temperature cycle performance and storage performance. The reason for this is that if the amount of additive is too high, the lithium ion insertion / extraction channels formed by the silicon polyalkoxide film become too saturated, the channel size shrinks, and the film thickness increases, which is not conducive to the smooth insertion / extraction of active lithium and degrades the effect of inhibiting lithium plating. On the other hand, if the amount of additive is too low, it is insufficient to absorb the oxygen generated by factors such as the reactivity of the lithium replenisher itself, resulting in poor effect of inhibiting battery expansion. By controlling the mass ratio of the additive to the lithium replenisher to be 1:(4-32), it is beneficial to absorb oxygen more fully while keeping the amount of additive less and reducing costs.

[0060] The positive electrode active material layer may also include a conductive agent and a binder. Both the conductive agent and the binder can be conventional types in the art. For example, the conductive agent may be selected from one or more of conductive carbon black, acetylene black, graphene, Ketjen black, and carbon fiber; the binder may be selected from one or more of polytetrafluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, polyethylene, polypropylene, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, ethylene oxide-containing polymers, polyvinylpyrrolidone, polyurethane, and polyvinylidene fluoride.

[0061] In the aforementioned positive electrode active material layer, the mass percentage of the positive electrode active material is 70%–99%, the mass percentage of the lithium supplement is 2%–4%, the mass percentage of the conductive agent is 0.5%–15%, and the mass percentage of the binder is 0.5%–15%. For example, the mass percentage of the positive electrode active material is 93%, the mass percentage of the lithium supplement is 3%, the mass percentage of the conductive agent is 2%, and the mass percentage of the binder is 2%.

[0062] In this embodiment, the positive current collector can be a conventional positive current collector in the art, such as one or more of aluminum foil and nickel foil.

[0063] The positive electrode sheet is prepared by the following process in the embodiments of this application: the positive electrode active material, lithium supplement, conductive agent and binder are dispersed in a solvent to obtain a positive electrode slurry, and then the positive electrode slurry is uniformly coated on at least one side surface of the positive electrode current collector. After drying, rolling, baking, slitting and spot welding of the tabs, the positive electrode sheet is obtained. These processes are all conventional processes in the art, and the embodiments of this application do not impose any special limitations on them. The solvent mentioned above may include N-methylpyrrolidone (NMP).

[0064] In addition, the battery also includes a negative electrode sheet, which comprises a negative electrode current collector and a negative electrode active material layer located on at least one side surface of the negative electrode current collector. The negative electrode active material layer comprises a negative electrode active material. The negative electrode active material may include carbon-based materials and / or silicon-based materials. Using this negative electrode active material, additives having the structure shown in Formula 1 absorb oxygen and form a dense silicon-containing polyalkoxy network channel, guiding active lithium ions to smoothly insert into the negative electrode, reducing polarization, thereby suppressing lithium plating problems, reducing interfacial impedance, and improving the high-temperature cycle performance and storage performance of the battery.

[0065] In some embodiments, the carbon-based material described above includes one or more of natural graphite, artificial graphite, hard carbon, and soft carbon.

[0066] In some embodiments, silicon-based materials include one or more of pure silicon materials, silicon-carbon materials, and silicon-oxygen materials.

[0067] The aforementioned negative electrode active material layer may further include a conductive agent, a binder, and a dispersant. The conductive agent, binder, and dispersant may be of conventional types in the art. For example, the conductive agent may be selected from one or more of natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, and graphene; the binder may be selected from one or more of carboxymethyl cellulose, styrene-butadiene rubber, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide-containing polymers, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamide-imide, polyvinyl alcohol, and sodium polyacrylate; and the dispersant may be selected from at least one of carboxymethyl cellulose, hydroxymethyl cellulose, and sodium hydroxymethyl cellulose.

[0068] In the aforementioned negative electrode active material layer, the mass percentage of the negative electrode active material is 70%–99%, the mass percentage of the conductive agent is 0.5%–15%, the mass percentage of the binder is 0.5%–15%, and the mass percentage of the dispersant is 0.5%–15%. For example, the mass percentage of the negative electrode active material is 95%, the mass percentage of the conductive agent is 1.5%, the mass percentage of the binder is 2%, and the mass percentage of the dispersant is 1.5%.

[0069] In this embodiment, the negative electrode current collector can be a conventional negative electrode current collector in the art. For example, the material of the negative electrode current collector layer can be one or more of copper foil, nickel foam, and copper foam.

[0070] The negative electrode sheet is prepared by the following process in the embodiments of this application: the negative electrode active material, conductive agent, binder and dispersant are dispersed in deionized water to obtain a negative electrode slurry, and then the negative electrode slurry is uniformly coated on at least one side of the negative electrode current collector. After drying, rolling, baking, cutting and spot welding of electrode tabs, the negative electrode sheet is obtained. These processes are all conventional processes in the art, and the embodiments of this application do not impose any special limitations on them.

[0071] The battery in this application embodiment may also include a separator. The separator may be made of separator materials commonly used in the art, such as one or more of the following: polypropylene separator (PP), polyethylene separator (PE), polypropylene / polyethylene bilayer composite membrane (PP / PE), polyimide electrospun separator (PI), polypropylene / polyethylene / polypropylene trilayer composite membrane (PP / PE / PP), cellulose nonwoven separator, and separator with ceramic coating.

[0072] The battery in this application embodiment can be manufactured by conventional methods in the art. For example, positive electrode, negative electrode and separator are stacked in sequence (separator is placed between positive electrode and negative electrode), and then wound to form a wound cell. The cell is placed in an outer packaging, and the electrolyte is injected into the cell in a glove box. Then it is left to stand, for example, for about 24 hours. It is pre-charged for a first formation, then sealed, and after a second formation, the battery is obtained.

[0073] The battery described above will be described in more detail below through specific embodiments.

[0074] Example 1

[0075] This embodiment prepares the battery through the following process:

[0076] In an argon-atmospheric glove box (water content <0.1ppm, oxygen content <1ppm), 12.5% ​​lithium hexafluorophosphate (by mass of the electrolyte) was added to 85% organic solvent (a mixture of EC, DMC, and EMC, with a mass ratio of EC:DMC:EMC of 3:1:6) to obtain a mixed solution. After cooling the mixed solution to room temperature, 0.5% of the additive shown in Formula 1-1 (by mass of the electrolyte) and 2% of vinylene carbonate (by mass of the electrolyte) were added and mixed thoroughly to obtain the electrolyte.

[0077] Lithium iron phosphate, lithium ferrite, conductive carbon black (super-p), and polyvinylidene fluoride (PVDF) were dispersed in N-methylpyrrolidone (NMP) at a mass ratio of 93:3:2:2 to obtain a positive electrode active material slurry with a solid content of 55 wt%. This slurry was then uniformly coated onto one surface of a 16 μm thick aluminum foil used as a positive electrode current collector, with a coating weight of 4.2 mg / cm². 2 After drying at 85℃, a positive electrode sheet with a single-sided coating of positive electrode material layer with a coating thickness of 168μm is obtained; the above steps are repeated on the other surface of the positive electrode current collector aluminum foil to obtain a positive electrode sheet with a double-sided coating of positive electrode material layer; after drying, rolling, baking, slitting and spot welding of electrode tabs, a positive electrode sheet with a specification of 558mm×55mm is obtained.

[0078] Graphite, conductive carbon black (super-p), styrene-butadiene rubber (SBR), and sodium carboxymethyl cellulose (CMC) were dispersed in deionized water at a mass ratio of 95:1.5:2:1.5 and stirred until homogeneous to obtain a negative electrode active material slurry with a solid content of 49 wt%. This negative electrode active material slurry was then uniformly coated onto one surface of a 9 μm thick copper foil negative electrode current collector, with a coating weight of 8.8 mg / cm². 2 After drying at 85℃, a negative electrode sheet with a single-sided coating of negative electrode material layer with a coating thickness of 109μm is obtained; the above steps are repeated on the other surface of the negative electrode current collector copper foil to obtain a negative electrode sheet with a double-sided coating of negative electrode material layer; after drying, rolling, baking, slitting and spot welding of electrode tabs, a negative electrode sheet with a specification of 708mm×59mm is obtained.

[0079] Enjie wet-process biaxially oriented diaphragm (PP / PE) with a thickness of 12μm was used as the diaphragm;

[0080] The positive electrode, negative electrode, and separator are stacked in sequence (the separator is placed between the positive and negative electrodes), and wound to obtain a battery cell. The electrode assembly is placed in an aluminum-plastic film packaging bag and dehydrated at 85°C. 6.2g of the electrolyte is then injected into the battery cell in the outer packaging in a glove box. The cell is then left to stand for 24 hours, pre-charged for a first formation, sealed, and then formed a second time to obtain the battery. The formation current for both formations is 0.1C, the upper limit voltage for formation is 3.65V, and the formation temperature is 45°C.

[0081] Following the process of Example 1, batteries of Examples 2 to 32 and Comparative Examples 1 to 3 were prepared respectively. In the battery of Comparative Example 3, no additives shown in Formula 1 were added during the preparation of the electrolyte. The mass percentage of organic solvent changed accordingly, while the percentage of other components in the electrolyte remained unchanged.

[0082] The types of additives used in each embodiment and comparative example are summarized in Table 1. The types of lithium replenishing agents, the mass percentage of additives in the electrolyte, the mass ratio of additives to lithium replenishing agents, the types of film-forming agents, and the mass percentage of film-forming agents in the electrolyte are summarized in Table 2. The mass ratio of EC:DMC:EMC is 3:1:6. The additive in Example 27 is shown in Formula 2, the additive in Example 28 is shown in Formula 3, and the additive in Example 29 is shown in Formula 3.

[0083] As shown in Equation 4.

[0084] Table 1 lists the types of additives used in each example and comparative example.

[0085] Table 1

[0086] In Table 1, " / " indicates that there are no relevant parameters.

[0087] Table 2 includes the types of lithium replenishing agents, the amount of lithium replenishing agents added, the mass percentage of additives in the electrolyte, the mass ratio of additives to lithium replenishing agents, the types of film-forming agents, and the mass percentage of film-forming agents in the electrolyte for each embodiment and comparative example. Specifically, the mass percentage of additives in the electrolyte is A, the mass percentage of organic solvents in the electrolyte is B, and the mass percentage of film-forming agents in the electrolyte is C.

[0088] Table 2

[0089] In Table 2, " / " indicates that there are no relevant parameters.

[0090] Test case

[0091] 1. The following parameters of the batteries in the above embodiments and comparative examples were tested:

[0092] 1) Storage performance test at 60℃

[0093] After the battery is sealed twice (gas removed), it is left to stand at 25°C for 30 minutes. Then, it is charged at a constant current of 1C to 3.65V, and further charged at a constant voltage of 3.65V until the current reaches 0.05C. Next, the battery is discharged at a constant current of 1C to 2.0V; this discharge capacity is recorded as C0. The battery is then charged again at a constant current of 1C to 3.65V, and further charged at a constant voltage of 3.65V until the current reaches 0.05C. The lithium-ion battery is then suspended by a thin thread and immersed in a container of water; the balance reading is recorded as m1. The battery is then stored at 60°C for 30 days. After storage, the battery is placed at 25°C, and again suspended by a thin thread and immersed in a container of water; the balance reading is recorded as m2. Finally, the battery is discharged at a constant current of 1C to 2.0V; this discharge capacity is recorded as C. 30 Then, charge the battery with a constant current of 1C to 3.65V, and further charge it with a constant voltage of 3.65V until the current is 0.05C; then discharge the lithium-ion secondary battery with a constant current of 1C to 2.0V. The discharge capacity at this point is denoted as C'. 30 .

[0094] Capacity retention rate (%) after 30 days of storage at 60℃ = C 30 / C0;

[0095] Capacity recovery rate (%) after 30 days of storage at 60℃ = C' 30 / C0;

[0096] The gas production ΔV (mL) was measured using the water displacement method, where ΔV = (m2 - m1) / ρ, and ρ is the density of liquid water.

[0097] After the battery was left to stand at 25°C for 30 minutes, its discharge DC internal resistance (DCIR) was tested and recorded as R0. Then, the battery was stored at 60°C for 30 days. After storage, the battery was placed at 25°C and its discharge DC internal resistance (DCIR) was tested again and recorded as R. 30 The unit is mΩ.

[0098] 2) 45℃ Cyclic Performance Test

[0099] Place the battery in a constant temperature chamber at 45℃±1℃ and let it stand for 3 hours to allow it to reach a constant temperature. In the chamber, charge the battery at a constant current and constant voltage of 1C to 3.65V, then charge it at 3.65V to the cutoff current of 0.05C, and then discharge it at 1C to 2.0V. Record the initial discharge capacity as C1. This constitutes one charge-discharge cycle. Repeat this cycle 500 times, and record the discharge capacity after the 500th cycle as C2. Capacity retention rate (%) after 500 cycles at 45℃ = C2 / C1 × 100%.

[0100] Before the high-temperature cycling performance test, the battery was removed, and the area of ​​the entire negative electrode interface was recorded as S0, and the area of ​​the lithium plating region at the interface was recorded as S1. After the high-temperature cycling performance test, the battery was removed, and the area of ​​the entire negative electrode interface was recorded as S, and the area of ​​the lithium plating region at the interface was recorded as S2. The percentage of lithium plating region at the negative electrode interface of the battery before 45℃ cycling (%) = S1 / S0 × 100%; the percentage of lithium plating region at the negative electrode interface of the battery after 500 cycles at 45℃ (%) = S2 / S × 100%.

[0101] The test results are shown in Table 3.

[0102] 2. Test Results

[0103] Table 3 Battery Performance

[0104] Analyze the data in the table above:

[0105] Comparison of the various embodiments and comparative examples revealed that the high-temperature storage performance, cycle performance and lithium plating problem of the batteries in each embodiment were improved, proving that the additive (siloxane or silane) with the structure shown in Formula 1 helps to suppress lithium plating problem, reduce interface impedance and improve the high-temperature cycle performance and storage performance of the battery.

[0106] A comparison of Examples 12 and 22-26 revealed that when the mass percentage of the film-forming agent in the electrolyte is 0.5% to 3%, preferably 0.5% to 2.5%, the synergistic effect of the film-forming agent and the additive is better, which more effectively improves the battery swelling and lithium plating problems, reduces impedance, and thus is more conducive to improving the high-temperature cycle performance and storage performance of the battery.

[0107] A comparison of Examples 12-17 revealed that the additive's mass percentage in the electrolyte is 0.2-2%, which is beneficial for sufficient oxygen absorption and does not cause excessive SEI film thickness leading to increased impedance, thereby avoiding battery capacity degradation.

[0108] A comparison of Examples 1, 12, 13-18 and Examples 8, 30-32 revealed that a mass ratio of additive to lithium replenisher of 1:(4-32) is beneficial for fully absorbing the generated oxygen while compensating for the loss of active lithium, thereby improving battery expansion and lithium plating problems, reducing impedance, and improving the high-temperature cycle performance and storage performance of the battery.

[0109] Based on Examples 1-32, by changing the amount of lithium replenishing agent added according to conventional standards in the art, the same technical effects as Examples 1-32 can still be achieved. This is beneficial for fully absorbing the generated oxygen while compensating for the loss of active lithium, thereby improving battery expansion and lithium plating problems, reducing impedance, and improving the high-temperature cycle performance and storage performance of the battery.

[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. An electrolyte, characterized by, The electrolyte is used in a battery comprising a lithium supplementing agent, the lithium supplementing agent being a lithium supplementing agent capable of decomposing to generate oxygen; the electrolyte comprises an additive represented by Formula 1, In Formula 1, R1, R2, R3, and R4 are each independently selected from C1-C5 alkyl, C2-C5 alkenyl, C2-C5 alkynyl, C6-C12 aryl, unsubstituted or R-substituted groups. a Substituted C3–C6 unsaturated cyclic hydrocarbon groups, unsubstituted or R a Substituted C1–C6 alkoxy groups, unsubstituted or R a Substituted C2–C6 olefins, unsubstituted or R a Substituted C2–C6 alkynyl groups, unsubstituted or R a The substituted C6-C12 aromatic phenolic oxygen group and heteroatom, at least one of R1, R2, R3, and R4 contains an unsaturated bond; the substituent R a Alkyl or halogen atoms selected from C1 to C5.

2. The electrolyte according to claim 1, characterized in that, The heteroatom is selected from N, O, S, Si. 3.The electrolyte of claim 1 or 2, wherein, R1 is selected from C1-C5 alkyl or C2-C5 alkenyl groups, R2 and R3 are each independently selected from C1-C5 alkyl, C2-C5 alkenyl, or C6-C12 aryl groups, and R4 is selected from unsubstituted or R-substituted groups. a Substituted C2–C6 olefins; Alternatively, R1 and R2 are each independently selected from C2-C5 alkenyl groups, R3 is selected from C1-C5 alkyl groups or C6-C12 aryl groups, and R4 is selected from unsubstituted or R-substituted groups. a Substituted C1–C6 alkoxy groups; or, the R1 is selected from C2-C5 alkenyl, the R2 is selected from C2-C5 alkenyl or C2-C5 alkynyl, the R3 is selected from C1-C5 alkyl or C2-C5 alkenyl, and the R4 is selected from C1-C5 alkyl. Alternatively, R1 is selected from C1-C5 alkyl groups, R3 is selected from C1-C5 alkyl groups or C2-C5 alkenyl groups, and R4 is selected from unsubstituted or R-substituted groups. a The substituted C1-C5 alkoxy or C2-C5 alkenyl group, wherein R2 is selected from the group shown in formula a. In equation a, R 11 Selected from N, O, C2-C5 alkenyl groups or *-OR 12 -O-*, where R 12 Selected from C1 to C5 alkyl groups, R 13 R 14 R 15 Each is independently selected from C1 to C5 alkyl groups, unsubstituted or R-substituted. b Substituted C1–C5 alkoxy or C2–C5 alkenyl groups; substituent R b Selected from C1 to C5 alkyl or halogen atoms; Alternatively, R1, R2, and R3 are each independently selected from those that are not substituted or have been replaced by R. c The substituted C1-C6 alkoxy group, wherein R4 is selected from the group shown in formula b; the substituent R c Selected from C1 to C5 alkyl or halogen atoms; 4. The electrolyte according to any one of claims 1 to 3, characterized in that, The additive represented by the formula 1 is selected from the group consisting of compounds represented by the formulae 1-1 to 1-12:

5. The electrolyte according to any one of claims 1 to 4, characterized in that, The mass percentage of the additive in the electrolyte is 0.2%-2%.

6. The electrolyte according to any one of claims 1 to 5, characterized in that, The lithium supplement agent comprises one or more of lithium nickelate, lithium ferrite, and lithium oxide.

7. The electrolyte according to any one of claims 1 to 6, characterized in that, The mass ratio of the additive to the lithium supplement agent is 1:(4-32).

8. The electrolyte according to any one of claims 1 to 7, characterized in that, The electrolyte further comprises a film-forming agent, the film-forming agent comprising one or more of cyclic carbonate, cyclic sulfate, and cyclic sulfonate lactone.

9. The electrolyte of claim 8, wherein, The mass percentage of the film-forming agent in the electrolyte is 0.5%-3%, preferably 0.5%-2.5%. and / or, the cyclic carbonate comprises vinylene carbonate and / or fluoroethylene carbonate; and / or, the cyclic sulfate comprises vinyl sulfate; and / or, the cyclic sulfonate lactone comprises 1,3-propane sulfonate lactone.

10. The electrolyte according to any one of claims 1 to 9, characterized in that, The electrolyte further comprises an organic solvent and an electrolyte salt, wherein, The organic solvent comprises one or more of carbonate solvent, carboxylate solvent, and ether solvent, the carbonate solvent comprises one or more of vinyl carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methyl ethyl carbonate, and methyl propyl carbonate, the carboxylate solvent comprises one or more of methyl formate, methyl acetate, methyl propionate, methyl butyrate, ethyl acetate, ethyl propionate, propyl propionate, and ethyl butyrate, and the ether solvent comprises one or more of tetrahydrofuran, 1,3-dioxolane, diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether; The electrolyte salt comprises one or more of lithium hexafluorophosphate, lithium bisfluorosulfonimide, lithium bis-trifluoromethanesulfonimide, and lithium tetrafluoroborate; The mass percentage of the electrolyte salt in the electrolyte is 8%-18%.

11. A battery, characterized by The battery comprises a positive electrode sheet comprising a lithium supplement agent and the electrolyte of any one of claims 1-10. The positive electrode sheet comprises a positive electrode current collector and a positive electrode active material layer located on at least one side surface of the positive electrode current collector, the positive electrode active material layer comprising the lithium supplement agent, and the positive electrode active material layer further comprising a positive electrode active material, the positive electrode active material comprising one or more of nickel-cobalt-manganese ternary material, nickel-cobalt-aluminum ternary material, nickel-cobalt-manganese-aluminum quaternary material, nickel-manganese-aluminum ternary material, lithium cobaltate, lithium manganate, lithium manganese iron phosphate, and lithium iron phosphate. and / or, the battery further comprises a negative electrode sheet comprising a negative electrode current collector and a negative electrode active material layer located on at least one side surface of the negative electrode current collector, the negative electrode active material layer comprising a negative electrode active material, the negative electrode active material comprising one or more of carbon-based material and silicon-based material, the carbon-based material comprising one or more of natural graphite, artificial graphite, hard carbon, and soft carbon, and the silicon-based material comprising one or more of pure silicon material, silicon-carbon material, and silicon-oxygen material.

12. The battery of claim 11, wherein, The lithium supplement agent comprises one or more of lithium nickelate, lithium ferrite, lithium oxide.

13. The battery of claim 11, wherein, The mass ratio of the additive and the lithium supplement agent is 1:(4-32).

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