The challenges and strategies towards high-performance anode-free post-lithium metal batteries.

With the merits of high theoretical energy density and ease of manufacture, anode-free post-lithium metal batteries have drawn extensive attention and have been rapidly emerging in recent years. However, the poor reversibility of metal anodes has severely hindered the realization of high-performance anode-free batteries. In this review, the critical challenges and strategies for achieving high-performance anode-free metal batteries are first elucidated. Then, the significant research studies devoted to promoting the reversibility of metal anodes for anode-free post-lithium (including sodium-, potassium- and zinc-) metal batteries are exclusively discussed to extract the principles for their practical implementation. Additionally, remedial solutions of supplying metal to the anode for improving the cyclability of anode-free batteries are also introduced. Finally, we summarize the advancements in anode-free post-lithium metal batteries, and propose some promising directions in this area. This review aims to provide a more comprehensive understanding towards the strategies for achieving highly reversible anode-free post-lithium metal batteries and a timely overview of the latest developments in this emerging field.