Gas‐Induced Surface Reconstruction for Stable Lithium‐Rich Manganese‐Based Cathodes

ABSTRACT Lithium‐rich manganese‐based materials (LRM) are promising high‐energy cathodes with the ability to undergo anionic redox for higher capacity, whose potential is unfortunately challenged by the associated stability issues related to oxygen release. Herein, we demonstrate the possibility to improve the electrochemical stability of LRM through a facile gas‐induced surface reconstruction (GSR) strategy involving a direct sintering of a mixture of LRM and artificial graphite (AG). We identify that the emergence of a CO 2 atmosphere during this heating treatment triggered the transition of the surface lattices from a layer‐typed feature into well‐regulated domains dominated by rock‐salt‐like structures, thereby effectively suppressing the activity of surface oxygen to combat the notorious interfacial side reactions. This surface‐engineered cathode exhibited improved cycling performance to achieve a capacity retention of 93.1% after 150 cycles when tested at 0.5 C as compared to only 65.8% for the untreated sample. Meanwhile, a suppressed voltage decay from 3.6 mV per cycle for the unmodified material to only 2.2 mV per cycle was observed. Our study highlights the critical role of surface chemistry in improving structural and electrochemical stability, and offering insights into surface lattice reconstruction to enhance the practical viability of high‐energy lithium‐ion batteries.