Ultralow-temperature resistant lithium battery electrolyte

Abstract

The invention relates to an ultralow-temperature resistant lithium battery electrolyte. The ultralow-temperature resistant lithium battery electrolyte comprises an organic solvent, a lithium salt electrolyte and an additive, wherein the additive is selected from one or more of potassium bromide, bi(trifluoromethanesulphonyl) sodium imide, bi(trifluoromethanesulphonyl) potassium imide and bi[bi(trifluoromethanesulphonyl) imide] zinc, and the mass content of the additive accounts for 0.05-0.15%. The potassium bromide with special content is used as the additive applied to an organic solvent of the lithium salt electrolyte, so that the electrolyte also has relatively high conductivity under a condition of 0 DEG C (particularly an extremely low temperature condition of (-60)-(-80) DEG C, so that normal circulation of the lithium battery is ensured, and the cycle property and the safety of the lithium battery under the extremely low temperature condition are substantially improved.

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.

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