锌负极和锂负极在不同温度下的电化学行为

Distinct chemistry between Zn and Li at varied temperature

本文研究表明锂金属负极的枝晶问题在较低温度下会加剧,在较高温度下会受到抑制;而对于水系可充电锌基电池中锌金属负极的枝晶演变,温度的影响则恰恰相反.对两种负极的电化学行为的研究结果表明,界面反应速率和离子扩散率的匹配程度以及副反应综合影响了金属负极的枝晶生长和循环寿命.研究发现有机电解质和水电解质在上述影响因素上的不同性质导致相反的温度影响.本文进一步对混合电解质(有机和水性)进行了详细研究,以调节离子扩散率和副反应,同时扩大水系可充锌基电池的工作温度窗口.本文揭示了有机锂金属负极和水系锌基电池完全相反的温度影响,并揭示了潜在的影响机制,有助于加深对金属负极的理解,从而促进水系锌基电池的大规模应用.

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.