Approaching Zero Voltage Attenuation of Lithium‐Rich Cathodes through Electrochemical Relaxation

ABSTRACT Li‐rich cathodes combining cationic/anionic redox have rejuvenated high‐energy batteries. However, their practical applications remain constrained by the inferior anion redox reversibility and stability. Herein, a facile electrochemical relaxation route was implemented for the first time in the initial charging process to tune the anion redox chemistry. It declares the electrochemical relaxation in the oxygen activation plateau of 4.6 V contributes to a lattice framework with reduced structural distortion and weakened O─O interactions. A back‐bonding π ‐bond is formed between Mn and the O─O dimer, strengthening the interactions between oxygen and Mn, mitigating structural degradation and local distortion during the electrochemical cycling. The relaxed material demonstrates a high capacity over 250 mAh g −1 and a high plateau voltage of 3.57 V with a negligible voltage decay (0.8%) after 100 cycles at 1C. This strategy presents a straightforward methodology for high‐voltage activation of O redox cathodes.