CN-115395104-B - Lithium battery and electrolyte

Abstract

The application discloses lithium battery electrolyte which comprises lithium salt, an organic solvent and an additive, wherein the additive is any one or more of fluoroethylene carbonate, vinylene carbonate, ethylene carbonate, succinonitrile, adiponitrile and hexanetrinitrile. The application also provides a lithium battery. The application relates to a lithium battery and electrolyte. The lithium battery electrolyte and the lithium battery provided by the application solve the problem that the PS content in the battery exceeds the standard, and simultaneously can ensure that the high temperature and the cycle performance of the battery are compatible and the high temperature performance of the battery can reach or be higher than the high temperature performance of the battery containing PS.

Inventors

• LIU PENG
• XU XIONGWEN
• WANG ZHIBIN
• HUANG YUXI

Assignees

• 湖南立方新能源科技有限责任公司

Dates

Publication Date

20260508

Application Date

20220926

Claims (1)

1. 1. A lithium battery comprises a positive plate, a negative plate, a diaphragm and electrolyte, and is characterized in that, The positive plate is prepared by mixing positive material lithium cobaltate, conductive agent Super-P and binder PVDF according to the mass ratio of 98:1:1, dispersing in an organic solvent NMP, stirring the mixture until the mixture is stable and uniform by using a vacuum stirrer to form positive paste, uniformly coating the positive paste on aluminum foil with the thickness of 12 mu m, airing the aluminum foil at room temperature, transferring the aluminum foil into a blast oven at 120 ℃ for drying for 1h, and then carrying out cold pressing and die cutting to prepare the positive plate; The negative electrode plate is prepared by mixing negative electrode material graphite, conductive agent Super-P, SBR and CMC according to the mass ratio of 97:0.5:1.5:1, dispersing in deionized water, stirring the materials to be stable and uniform by using a vacuum stirrer to form negative electrode slurry, uniformly coating the negative electrode slurry on copper foil with the thickness of 6 mu m, airing the copper foil at room temperature, transferring the copper foil into a blast oven with the temperature of 120 ℃ for drying for 1h, and then carrying out cold pressing and die cutting to prepare the negative electrode plate; The electrolyte is prepared from any one of the following components: Mixing LiPF 6 , mixed organic solvent PC/DEC/pp=10/20/70, and FEC, SN, ADN, HTCN, liODFB, VC and VEC, stirring with a vacuum stirrer until the mixture is stable and uniform to obtain electrolyte, wherein the mass of LiPF 6 , mixed organic solvent FEC, SN, ADN, HTCN, liODFB, VC and VEC respectively accounts for 15%, 69.7%, 10%, 1%, 2%, 0.5%, 0.3% of the total mass of electrolyte, or, LiPF 6 , mixed organic solvent PC/DEC/pp=10/20/70, and FEC, SN, ADN, HTCN, liODFB, VC and VEC are mixed, and stirred to be stable and uniform by using a vacuum stirrer to obtain electrolyte, wherein the mass of LiPF 6 , mixed organic solvent FEC, SN, ADN, HTCN, liODFB, VC and VEC respectively accounts for 15%, 69.0%, 10%, 1%, 2%, 0.5%, 1%, 0.5% or, LiPF 6 , mixed organic solvent PC/DEC/pp=10/20/70, and FEC, SN, ADN, HTCN, liODFB, VC and VEC were mixed and stirred to be stable and uniform using a vacuum stirrer to obtain an electrolyte, wherein the mass of LiPF 6 , mixed organic solvent FEC, SN, ADN, HTCN, liODFB, VC and VEC respectively accounts for 17%, 67.7%, 10%, 1%, 2%, 0.5% and 0.3% of the total mass of the electrolyte.

Description

Lithium battery and electrolyte Technical Field The application relates to the technical field of lithium batteries, in particular to a lithium battery and electrolyte. Background Along with the social development, the traditional fossil energy cannot meet the production and living needs, and meanwhile, many environmental problems are brought, and the development of novel renewable energy sources becomes a necessary trend. The lithium ion battery has been widely used in electric vehicles, notebook computers, energy storage and the like due to its advantages of high energy density, long cycle life, environmental friendliness and the like. In recent years, the european union chemical administration (ECHA) has performed tabulated management of substances that may be carcinogenic, distorted, or have reproductive toxicity, as well as, bioaccumulative and other substances that have serious impact on humans and the environment, i.e., substances of high concern (Substances of Very High Concern, SVHC). The EU stipulates that if the commodity product which is put into the EU market contains any SVHC candidate substance with the concentration of more than 0.1%, the EU manufacturer or importer should fulfill the obligations of informing, reporting and the like specified by REACH rule, when the commodity product contains any SVHC candidate substance with the concentration of more than 0.1% and the total amount of the substance entering the EU is more than 1 ton/year, the EU manufacturer or importer must firstly notify ECHA, and the product side can be sold in the EU market. In order to ensure the high temperature performance of the battery, a certain amount of 1, 3-propane sultone (PS for short) is added into the conventional electrolyte at present, the content of the 1, 3-propane sultone in the electrolyte of the digital battery is generally more than or equal to 3wt percent, the content of the 1, 3-propane sultone in the power is generally less than or equal to 2 percent, and the content in the battery is converted More than or equal to 0.1 percent. The 1, 3-propane sultone belongs to SVHC candidate substances, so that most of the batteries in the market at present do not meet the requirement that the PS content in the batteries is less than or equal to 0.1 percent, the outlet is greatly affected, and the 1, 3-propane sultone contained in the batteries also threatens the environment. Therefore, how to develop a lithium ion battery with low content of 1, 3-propane sultone in the battery and performance meeting the use requirement is a technical problem to be solved by the person skilled in the art. Disclosure of Invention In order to solve the technical problems, the first object of the application is to provide a lithium battery electrolyte, the second object of the application is to provide a lithium battery, and the lithium battery electrolyte and the lithium battery provided by the application solve the problem that the PS content in the battery exceeds the standard, and simultaneously can ensure that the high temperature performance and the cycle performance of the battery are compatible, and the high temperature performance can reach or be higher than the high temperature performance of the battery containing PS. The technical scheme provided by the invention is as follows: A lithium battery electrolyte comprises lithium salt, organic solvent and additive, Wherein the additive is any one or more of fluoroethylene carbonate, vinylene carbonate, ethylene carbonate, succinonitrile, adiponitrile and hexanetrinitrile. Preferably, the additive comprises any one or more of fluoroethylene carbonate, vinylene carbonate and ethylene carbonate, and any one or more of succinonitrile, adiponitrile and hexanetrinitrile. Preferably, the mass ratio of the ethylene carbonate to the ethylene carbonate is (5-20): 0-1, and the mass ratio of the succinonitrile, the adiponitrile and the hexanetrinitrile is (0-2): 0-3. Preferably, the lithium salt is one or more of lithium hexafluorophosphate, lithium perchlorate, lithium difluorophosphate and lithium difluorooxalato borate, and/or, In the electrolyte, lithium salt accounts for 10-18% of the total mass of the electrolyte, organic solvent accounts for 60-80% of the total mass of the electrolyte, and additive accounts for 10-30% of the total mass of the electrolyte. Preferably, the organic solvent includes carbonates and carboxylates, wherein the carbonates include cyclic carbonates and chain carbonates. Preferably, the mass ratio of the cyclic carbonate to the chain carbonate to the carboxylic acid ester is (10-50): 20 (30-70). Preferably, the cyclic carbonate comprises one or more of ethylene carbonate, propylene carbonate; The chain carbonate comprises one or more of dimethyl carbonate, diethyl carbonate and methyl ethyl carbonate; the carboxylic acid ester comprises one or two of propyl acetate, butyl acetate, ethyl propionate and propyl propionate. Preferably, the ethylene carbonate