Electrolyte for lithium ion battery and preparation method thereof

Abstract

The invention discloses an electrolyte for a lithium ion battery and a preparation method thereof. The electrolyte consists of a main electrolyte, an electrolyte additive, a main solvent and a solvent additive. The preparation method comprises the following steps of: A. under the condition of vacuum or inert gas protection, respectively mixing the main solvent and the solvent additive with a drying agent (lithium oxide) which is dried to be at constant weight in advance, and mixing and filtering to remove the lithium oxide and lithium hydroxide sediment; B. uniformly mixing the dried main solvent and the dried solvent additive from the step A; and C. adding a main electrolyte mixture and an electrolyte additive into the solvent mixed in the step B, and agitating and dissolving under the vacuum and inert gas protection to prepare a solution with the mass mol concentration of the main electrolyte of 0.5-1.5 M. The electrolyte has the advantages of abundant resources, low price and no toxin, effectively improves the work temperature range of the battery and effectively prolongs the circulating service life of the battery, so that various types of the lithium ion batteries are manufactured; and the electrolyte is particularly suitable for manufacturing a lithium ion power battery with high power capacity and high multiplying power charging and discharging capacity.

Description

Technical field [0001] The present invention relates to the technical field of chemical power sources, and more specifically to a lithium ion battery electrolyte, and also to a method for preparing lithium ion battery electrolyte. It can be used to manufacture various types of lithium ion batteries and is also suitable for manufacturing High-rate charge-discharge lithium-ion power battery. Background technique [0002] At present, the electrolyte used in lithium-ion batteries manufactured by existing industries is mainly LiPF 6 , LiBF 4 Etc. for electrolytes, the electrolyte concentration is 0.1~2.0M (mol / L, hereinafter referred to as M) EC-EMC, EC-EMC-EMC, EC-EMC-DEC, EC-DMC-DEC-PC (where EC is ethylene carbonate Ester, EMC is ethyl methyl carbonate, DEC is diethyl carbonate, DMC is dimethyl carbonate, PC is propylene carbonate, the same below) and other organic solvent solutions. The electrolyte has a great influence on the performance of lithium-ion batteries. This is because...

AI Technical Summary

Problems solved by technology

[0004] Based on the above-mentioned relevant research on the existing lithium-ion battery electrolyte and the relevant published patented technologies, it can be seen that the existing technology uses lithium salts as electrolytes, common organic solvents as solutions, and certain functional additives. Lithium-ion batteries manufactured by the liquid solution obviously have the following deficiencies: 1) the high temperature or low temperature work performance is poor, and even at high (above 55°C) or low (below -30°C) batteries cannot work at all or have poor work performance; 2) ) The charging and discharging effect of the power type lithium-ion battery is poor, which affects the normal operation of the lithium-ion battery pack and severely limits the application range of the lithium-ion power battery; 3) The battery storage capacity is severely attenuated, which directly affects the capacity and cycle of the lithium-ion battery 4) poor anti-overcharge performance, which affects the charging and discharging efficiency, battery capacity and cycle life of lithium-ion batteries; 6) Many electrolyte solvents such as furan, pyridine, and acetone are highly toxic, which will more or less cause a certain degree of pollution in the production and use of lithium-ion batteries and the process of waste batteries

Although the above deficiencies are not entirely caused by the electrolyte of lithium-ion batteries, all the deficiencies have a direct impact on the conductivity of the electrolyte, compatibility with the electrodes, charge and discharge performance of the electrodes, cycle life, and battery safety.

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