Refillable lithium-ion battery

Abstract

The invention discloses a lithium ion battery with adoption of secondary electrolyte injection, comprising a positive pole, a negative pole, a diaphragm, an electrolyte and an outer package. In the process of manufacturing the battery, the secondary electrolyte injection is adopted; the electrolyte solvent in the first electrolyte injection is one or a combination of more than one of EC (ethylene carbonate), PC (propylene carbonate), DMC (dimethyl carbonate), DEC (diethyl carbonate), EMC (ethyl methyl carbonate), Gamma-BL (butyrolactone), MF (methyl formate), MA (methyl acetate), EP (ethyl propionate) and THF (tetrahydrofuran) and does not contain acetonitrile and propionitrile; the secondary electrolyte injection is conducted after the formation; and the used electrolyte in the secondary electrolyte injection contains at least one of the acetonitrile and the propionitrile. The electrolyte containing the at least one of the acetonitrile and the propionitrile has the advantage of high normal-temperature conductivity (10-50mS / cm) and low-temperature conductivity (4-20mS / cm at the temperature of -20 DEG C), thereby exceeding the level of an existing electrolyte.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to an electrolyte solution containing acetonitrile or propionitrile and a lithium ion battery using the electrolyte solution. Background technique [0002] Compared with lead-acid batteries, nickel-metal hydride batteries, and nickel-cadmium batteries, lithium-ion batteries have the advantages of higher energy density, small self-discharge, and long cycle life, and have been widely used in the field of consumer electronics. [0003] Electrolyte is an important part of lithium-ion batteries. It is the carrier and medium for the transmission of lithium ions between the positive and negative electrodes, and also provides lithium ions. The conductivity of the electrolyte is one of the important parameters of the electrolyte, which has an important impact on the performance of the specific capacity and rate of the electrode active material. [0004] Currently commonly use...

AI Technical Summary

Problems solved by technology

The use of acetonitrile-containing electrolyte will cause a large amount of gas to be generated when the battery is formed, and the battery performance will deteriorate

The root cause of this result is that the graphite anode cannot form a good SEI (solid electrolyte interface layer), so the reduction reaction of acetonitrile cannot be suppressed, so the electrolyte containing acetonitrile cannot be directly used as the electrolyte of lithium-ion batteries