A kind of ultra-low temperature resistant lithium battery electrolyte

Abstract

The invention relates to an ultra-low temperature resistant lithium battery electrolyte, which comprises: an organic solvent; a lithium salt electrolyte; an additive, the additive being selected from potassium bromide, bis(trifluoromethylsulfonyl)imide sodium, bis(tri One or more groups of potassium fluoromethylsulfonyl)imide and zinc bis[bis(trifluoromethanesulfonyl)imide], the mass content of which is 0.05%-0.15%. By using a specific content of potassium bromide as an additive and applying it to an organic solvent containing a lithium salt electrolyte, the electrolyte has a high conductivity below 0°C (especially at extremely low temperatures of -60°C-80°C) , so as to ensure the normal progress of the lithium battery cycle, and greatly improve the cycle performance and safety performance of the lithium battery under extreme low temperature conditions.

Description

technical field [0001] The invention belongs to the field of lithium batteries and relates to an electrolyte, in particular to an ultra-low temperature resistant lithium battery electrolyte. Background technique [0002] Counting from the dispatch of the first Antarctic expedition team in 1984, China’s Antarctic work has gone through 33 years. Although compared with some developed countries or countries with geographical advantages in the southern hemisphere, China started relatively late, but it has developed rapidly. As far as the construction of scientific research stations is concerned, China has built and put into operation 4 stations, they are the Great Wall Station, Zhongshan Station, Kunlun Station and Taishan Station. During the Antarctic scientific expedition, the demand for energy is self-evident. Especially in extreme conditions in cold regions such as Antarctica, the requirements for energy storage become particularly stringent. [0003] Since 2015, my country...

AI Technical Summary

Problems solved by technology

However, for ordinary commercial lithium batteries, the capacity decays rapidly at a low temperature of 0°C, only 10% of that at room temperature, or even lower

Such commercial lithium batteries are far from being able to meet research work in military, aerospace, Antarctic scientific research, etc., and cannot even be used in the Northeast region in winter.

The aging mechanism of lithium batteries under low temperature conditions is mainly due to the high resistance of the electrolyte under low temperature conditions, which leads to a decrease in the diffusion capacity of lithium ions inside the lithium battery.

Images