Mechanism study on the cycling stability of silicon-based lithium ion batteries as a function of temperature

Adapting to a wide operating temperature range is an inevitable trend in the development of rechargeable batteries. This work investigates the cycling stability of silicon (Si)-based half and full cells at a wide temperature range and the associated capacity fading mechanisms. Results show that compared with room temperature (25 °C), low temperature (0 °C) causes a decrease in capacity due to sluggish kinetics, and high temperature (60 °C) results in the lowest first Coulombic efficiency and the worst cycling stability with different capacity fading mechanisms in the half and full cells. In addition, composition and stability of solid-electrolyte interphase films are strongly temperature sensitive. Specifically, high temperature aggravates the dissolution of organic layer and the degradation of lithium hexafluorophosphate, and low temperature is not conducive to the formation of lithium carbonate. This work clearly reveals the problems that need to be solved to realize the application of Si anodes at a wide temperature range, which has important guiding significance for promoting the development and application of Si anodes in lithium ion batteries.