Building Stable Anodes for High‐Rate Na‐Metal Batteries

Abstract

Due to the low‐cost and high energy density, sodium metal batteries (SMBs) have attracted growing interests, with great potential to power future electric vehicles (EVs) and mobile electronics, which require the rapid charge/discharge capability. However, the development of high‐rate SMBs has been impeded by the sluggish Na+ ion kinetics, particularly at the sodium metal anode (SMA). The high‐rate operation severely threatens the SMA stability, due to the unstable solid‐electrolyte interface (SEI), the Na dendrite growth, and large volume changes during Na plating‐stripping cycles, leading to rapid electrochemical performance degradations. In this paper, we survey key challenges faced by high‐rate SMAs, and we highlight representative stabilization strategies, including the general modification of SMB components (including the host, Na metal surface, electrolyte, separator, and cathode), and emerging solutions with the development of solid‐state SMBs and liquid metal anodes; we elaborate the working principle, performance, and application of these strategies, to reduce the Na nucleation energy barriers and promote Na+ ion transfer kinetics for stable high‐rate Na metal anodes. This review will inspire further efforts to stabilize SMAs and other metal (e.g., Li, K, Mg, Zn) anodes, promoting high‐rate applications of high‐energy metal batteries towards a more sustainable society.This article is protected by copyright. All rights reserved