Synergistic design of O2/O3 composite Li-rich cathodes: A novel strategy for high-performance Li-ion batteries

Due to their unique anion and cation redox mechanisms, Li-rich Mn-based layered oxide cathodes are considered extremely promising candidates for next-generation high-performance Li-ion batteries. However, their practical applications are limited by capacity degradation, voltage degradation, and poor rate performance. In this work, an O2/O3 composite Li-rich cathode was constructed by integrating nanoscale O3 particles on the surface of O2 microspheres. By combining the inherent excellent voltage retention of the O2-type structure with the nanostructured O3 rate advantage, the O2/O3 composite cathodes exhibit excellent specific capacity, cycling stability, and rate performance. Thanks to the synergistic effect of O2 and O3, the obtained composite cathode has a high discharge specific capacity of 298.06 mAh g -1 at 0.1C. It maintains 85.34% capacity retention after 100 cycles at 0.5C and still delivers a discharge specific capacity of 144.64 mAh g -1 at 5C. Based on experiments and theoretical calculations, the potential impact of the O2/O3 interface on electrochemical performance is elucidated. The built-in electric field at the two-phase interface plays a crucial role in structural stability. The O2/O3 composite cathode developed in this study holds potential to advance the development of high-performance Li-ion batteries. The O2/O3 composite cathode constructed in this study exhibits excellent specific capacity, cycling stability, and rate performance, benefiting from the synergistic effect between the O2 and O3 phases and the contribution of the O2/O3 interface. • A novel O2/O3 composite cathode has been designed and constructed. • Harnessing O2/O3 phase synergy to resolve limitations of single-phase cathodes. • O2/O3 composite cathodes demonstrates improved electrochemical performance. • Investigating O2/O3 interface effects on electrochemical performance.