Revealing Lithium Battery Gas Generation for Safer Practical Applications

Abstract Gases generated from lithium batteries are detrimental to their electrochemical performances, especially under the unguarded runaway conditions, which tend to contribute the sudden gases accumulation (including flammable gases), resulting in safety issues such as explosion and combustion. The comprehensive understanding of battery gas evolution mechanism under different conditions is extremely important, which is conducive to realizing a visual cognition about the complex reaction processes between electrodes and electrolytes, and providing effective strategies to optimize battery performances. This review aims to summarize the recent progress about battery gas evolution mechanism and highlight the gas suppression strategies to improve battery safety. New approaches toward future gas evolution analysis and suppression are also proposed. It is anticipated that this review will inspire further developments of lithium batteries on performance, gas suppression, and safety, especially in high energy density systems.