Design Principles of structured lithium metal anodes for high-energy batteries

Abstract

Lithium metal batteries (LMBs) hold promise as a next-generation energy storage technology due to their ultra-high theoretical specific capacity and energy density. The functioning of LMBs heavily relies on stable, high-capacity, and fast charging/discharging Li metal anodes (LMAs). However, the plating/stripping of the Li metal on the widely used “host-less” Li foil results in severe dendrite growth and low reversibility, hindering the practical application of LMBs. Unlike conventional Li foil, LMAs with delicately designed bulk structures, denoted as structured LMAs, regulate Li deposition behavior through the incorporated framework, providing an effective way of containing the inherent defects of LMAs, such as infinite volume expansion, the uncontrollable growth of Li dendrites, and excessive side reactions with electrolytes. Despite huge progress, the design of structured LMAs lacks a systematic summary, and deep insights into their structure–property relationships are unavailable. This review underlines the challenges in the design and fabrication of structured LMAs and categorizes and summarizes the current progress in the research on structured LMAs in detail, highlighting the interplay of framework components in regulating the deposition behavior of the Li metal. We also discuss the existing challenges and possible design criteria for fabricating structured LMAs and provide an outlook on some promising directions for future research. The aim of this review is to provide guidance for the rational design of LMAs with unique structures for the fabrication of next-generation high-energy-density batteries.