Effect of temperature on silicon-based anodes for lithium-ion batteries

Silicon is considered a promising anode candidate to replace graphite in lithium-ion (Li-ion) batteries for electric vehicle (EV) applications, given its high capacity (approximately 10 times higher than graphite) and, consequently, the higher energy density it can provide. However, to ensure that silicon can be used in EVs, it is necessary to determine whether it can withstand the temperature changes that an EV can experience. For this purpose, we evaluate the electrochemical performance of silicon-graphite (Si-Gr) half-cells at 4 different temperatures and explore the effect of adding fluoroethylene carbonate (FEC) to the electrolyte. We observe that cells cycled without FEC are temperature-sensitive; that is, the specific capacity, cyclability, and coulombic efficiency of Si-Gr vary as a function of the temperature applied. Conversely, the presence of FEC in the cell stabilizes the electrochemical behavior of Si-Gr, diminishing its sensitivity to temperature and providing similar reversible capacity, coulombic efficiency, and cycle-life. In this manuscript, we provide an explanation of the reasons causing this phenomenon along with other side effects of temperature, as proved by several characterization techniques.