Advanced 3D-structured electrode for potassium metal anodes

The potassium (K) metal anode, following the "Holy Grail" Li metal anode, is one of the most promising anode materials for next-generation batteries. In comparison with Li, K exhibits even more pronounced energy storage properties. However, it suffers from similar challenges as most alkali metal anodes, such as safety and cyclability issues. Borrowing strategies from Li/Na metal anodes, the three-dimensional (3D)-structured current collector has proven to be a universal and effective strategy. This study examines the recent research progress of 3D-structured electrodes for K metal anodes, focusing on the most commonly used host materials, including carbon-, metal-, and MXene-related electrode materials. Finally, existing challenges, various perspectives on the rational design of K metal anodes, and the future development of K batteries are presented.