Comprehensive Insights into Rechargeable Magnesium Oxygen and Magnesium Carbon Dioxide Batteries

ABSTRACT Rechargeable magnesium‐oxygen batteries (RMOBs) and magnesium‐carbon dioxide batteries (RMCBs) have emerged as a prominent research focus for next‐generation sustainable energy storage systems due to their high energy density, low cost, and environmental friendliness. Recent advances have been achieved rapidly, with gradual clarification of discharge mechanisms and the development of effective catalysts improving electrochemical performance. However, sluggish redox reaction kinetics, electrolyte instability, and unsatisfactory cycle lifespan continue to limit their application. Herein, this review concentrates on the reversibility of discharge products in RMOBs and RMCBs, examining three key aspects: cathode catalyst design, electrolyte optimization, and interphase regulation. The energy barriers for generating and decomposing discharge products can be reduced through rational cathode catalyst design and strategic electrolyte modulation, which synergistically optimize reaction pathways. Additionally, optimizing the electrode interphase has emerged as an attractive approach to enhance reaction kinetics. Finally, we summarize the challenges and bottlenecks of these systems and provide insightful perspectives on future research directions and potential breakthroughs. This study is anticipated to further elucidate discharge products formation and decomposition mechanisms, propose strategies for interphase optimization, and guide the design of high‐performance RMOBs and RMCBs.