Flatulence-proof electrolytic solution for iron phosphate lithium battery

Abstract

The invention relates to an anti-swelling electrolyte for lithium iron phosphate batteries, which comprises the following components: (1) a mixture composed of at least three solvents with high dielectric constant and low viscosity selected from ethylene carbonate, diethyl carbonate, dimethyl carbonate and ethylmethyl carbonate as a major solvent with the total content of 95%-98%; (2) fluoroethylene carbonate and battery-grade Li2CO3 as the functional additives for preventing swelling and bulging, wherein the contents of fluoroethylene carbonate and battery-grade Li2CO3 are 1%-3% and 1%-2% respectively and the total content thereof is 2-5%; and (3) the concentration of the lithium salts is 0.8-1.2 mol / L. The anti-swelling electrolyte for the lithium iron phosphate batteries can absorb the moisture in the electrode so as to prevent the batteries from swelling and bulging. Additionally, a dense SEI film is formed on the surface of the cathode to effectively improve the electrochemical performance of the lithium iron phosphate battery. Furthermore, Li2CO3 in the electrolyte can effectively increase the capacity per gram of lithium iron phosphate, and further increase the energy density of the lithium iron phosphate battery.

Description

technical field [0001] The invention relates to an electrolyte solution for a lithium ion battery, in particular to an anti-flat electrolyte solution for a lithium iron phosphate battery. Background technique [0002] Energy crisis, resource shortage, and environmental pollution are severe challenges facing human existence. Finding clean, renewable, resource-saving secondary energy is an important task to be solved to realize the sustainable development of human society. [0003] Lithium iron phosphate is widely regarded as the preferred cathode material for next-generation power batteries because of its good safety performance, long cycle life, and environmental friendliness. However, lithium iron phosphate cathode material also has a fatal shortcoming, that is, low electrical conductivity, which greatly affects LiFePO 4 Applications. [0004] At present, in order to overcome this shortcoming, people prepare ultrafine particles, increase the specific surface area of ​​the...

AI Technical Summary

Problems solved by technology

Especially for lithium iron phosphate, it is easy to cause gas swelling, which has a serious negative impact on the electrochemical performance and safety performance of lithium iron phosphate battery