In situ built interphase with high interface energy and fast kinetics for high performance Zn metal anodes

By Y. Chu, Shu Zhang, Shuang Wu, Zhenglin Hu, G. Cui, Jiayan Luo. 2021

174 citations recorded by the source corpus.

In-situ constructing multifunctional solid electrolyte interphase (SEI) for Zn anode is promising to address the dendrite growth and side reactions (corrosion and hydrogen evolution) in aqueous Zn-ion batteries. However, there is a lack of constructive methods for choosing suitable SEI compounds and feasible implementation routes. Here, inspired by SEI-design for Li-metal batteries, we identified that Zn3(PO4)2 with high interface energy could suppress Zn dendrite growth effectively and ZnF2 could accelerate the kinetics of Zn2+ transference and deposition, thus constructing a Zn3(PO4)2-ZnF2 composite SEI (ZCS) is likely to improve interface deposition and electrode kinetics comprehensively. However, the high redox potential of Zn/Zn2+ make it difficult to develop an in-situ SEI for Zn anode in aqueous electrolytes via traditional electrochemical route. Considering this dilemma, we take advantage of the instability of KPF6 in aqueous environment and build in-situ ZCS on Zn anode through PF6- anion-induced chemical strategy. Surprisingly, the ZCS protencted Zn exhibits enhanced reversibility with smooth and compact structure during long-term cycling. Both cumulative capacity (2020 mA h cm-2) and the product of largest current density and areal capacity (10 mA cm-2 × 20 mA h cm-2) reach the highest levels compared with recent reports under mildly acidic condition. This work paves a new way for designing desirable SEI on Zn anode and may also enlighten other systems to overcome intrinsic defects in constructing favorable interphases.

Subfields: Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/c11537d17e25484a87b79b3484c2663f173b53d9