Thermally activated secondary battery using low-temperature molten salt electrolyte

Abstract

The invention provides a thermally activated secondary battery using a low-temperature molten salt electrolyte based on a lithium / oxygen reaction mechanism. The thermally activated secondary battery comprises the low-temperature molten salt electrolyte, a lithium cathode, an oxygen anode and a diaphragm positioned between the anode and the cathode, wherein the low-temperature molten salt electrolyte consists of alkali metal cations and di(sulfonyl fluoride)imine anions, and particularly consists of di(sulfonyl fluoride)lithium imide and one, two or three of four non-lithium salts, namely, di(sulfonyl fluoride)sodium imide, di(sulfonyl fluoride)potassium imide, di(sulfonyl fluoride)rubidium imide and di(sulfonyl fluoride)cesium imide. The molten salt electrolyte in the invention is in a molten state at the temperature of 40-100 DEG C, and has the advantages of low melting temperature, freeness from volatilization, incombustibility, high chemical stability and high ion conductivity. Charging and discharging reactions are finished on the basis of a lithium / oxygen reaction, so that the problems of high battery working temperature, short working time after activation, low energy density, failure in charging after activation and the like in a conventional thermally activated battery can be effectively solved. The thermally activated secondary battery provided by the invention has wide application prospects in the fields of national defense, industrial use and civil use.

Description

technical field [0001] The invention relates to an electrochemical energy storage device, in particular to a thermally activated secondary battery using a low-temperature molten salt electrolyte. Background technique [0002] Thermal battery is a thermally activated reserve battery, which uses the battery's own heating system to heat and melt the non-conductive solid salt electrolyte into an ionic conductor to enter the working state. Once the thermal battery is activated, as long as the electrolyte remains molten, it can continuously output electricity until the active substances participating in the reaction are exhausted, or the electrolyte will re-solidify due to the heat loss inside the battery, causing the battery to stop outputting electricity. Thermal batteries occupy a very important position in military, industrial and civilian fields due to their characteristics of high-power discharge, high specific power, wide operating environment temperature, long storage time...

AI Technical Summary

Problems solved by technology

[0005] At present, thermal batteries have been widely used in national defense and military fields, but thermal batteries still face the following disadvantages: 1) Short working time after activation (usually no more than 10min); 2) Moderately low specific energy, energy density is usually No more than 40Wh / kg; 3) The working temperature of the battery is high (generally above the melting point of lithium, which is 180°C); 4) After activation, it can only be used once and cannot be charged

At present, the molten chloride, molten nitrate and other electrolyte systems commonly used in thermal batteries generally have a high melting temperature, requiring a lot of external energy supply to keep the battery in working condition, reducing energy utilization efficiency and increasing danger.

Images