New Type of Dynamically "Solid-Liquid" Interconvertible Electrolyte for High-Rate Zn Metal Battery.

ABSTRACT

The practical application of aqueous high-rate Zn metal battery (ZMB) is limited due to accelerated dendrite formation at high current densities. It is urgent to find an electrolyte, which could not only be mechanically stiff to clamp down dendrites but also not sacrifice ionic conductivity and interfacial compatibility. Herein, a new type of dynamically "solid-liquid" interconvertible electrolyte based on non-Newtonian fluid (NNFE) is proposed. Liquidity characteristic of NNFE is favorable for electrochemical kinetics and interfacial compatibility. Furthermore, in an area with high current rate NNFE would respond and mechanically stiffen to dissuade localized increase in Zn dendrite growth. Even at a current density of 50 mA cm-2, NNFE enables reversible and stable operation of a Zn symmetrical cell over 20 000 cycles. For Zn//Na5V12O32 (NVO) full cell, the NNFE also realizes lengthy cycling for 5000 periods at 5 A g-1. This research opens up new inspirations to high-rate Zn metal even other metal batteries.