Aqueous manganese-ion batteries: The past, present, and future

Aqueous manganese-ion batteries (AMIBs) have emerged as a promising alternative in aqueous rechargeable batteries. However, AMIBs still face critical challenges, including insufficient stability of cathode materials, limited reversibility of the anode, and a restricted electrochemical stability window. Addressing these issues requires in-depth understanding of the underlying reaction mechanisms and formulation of effective strategies. This review systematically provides an overview of the latest advances in AMIBs, critically assesses the main challenges that hinder their practical application, and highlights innovative approaches to overcome these obstacles. Key strategies related to the design and modification of anode and cathode materials with optimized energy storage mechanisms, as well as the fine-tuning of electrolyte compositions, have been comprehensively dissected. Ultimately, this review aims to delineate future research directions and bridge the gap between advances in basic materials and industrial deployment, thereby accelerating the large-scale commercialization of aqueous batteries.