Distinct chemistry between Zn and Li at varied temperature

Abstract

The operating temperature of batteries is an essential consideration in actual applications. Understanding the temperature dependence is conducive to battery design. The experience in lithium-ion batteries (LIBs) indicates that the dendrite issue is exacerbated at lower temperatures and suppressed at higher temperatures. In this study, we revealed the dendrite evolution in aqueous rechargeable zinc-based batteries (RZBs), for which the opposite temperature dependence was observed. Detailed investigations elucidate that the degree of matching of the interface reaction rate and ion diffusivity, together with side reactions, are the key factors that determine the cycling performance. The different properties of organic and aqueous electrolytes result in a reversed temperature dependence. We further conducted a detailed investigation of hybrid electrolytes (organic and aqueous) for balancing the ion diffusivity and side reactions to broaden the working temperature window for RZBs. This work reveals a completely opposite temperature dependence for LIBs and RZBs and discloses the underlying mechanism, reminding one of the differences between LIBs and RZBs in many aspects.

Keywords: Hybrid electrolytes; Metal anodes; Temperature dependence; Zn dendrites.