Surface modification of boron cobalt complexes to enhance cycling performance of cobalt-free Li-rich cathode materials

The instability of the anionic redox reaction and the resulting irreversible oxygen release are the core causes of the deterioration of the cycling stability of Li-rich cathode materials (LRM). The effective method is to establish a surface coating on the LRM, which is equivalent to converting surface oxygen on the LRM into bulk oxygen. However, developing a coating that can form a solid binding with the surface oxygen of the LRM remains challenging. To solve the above challenge, a uniform surface boron cobalt complexes (BCCs) coating was constructed on cobalt-free LRM. The constructed BCCs coating can significantly mitigate the interface side reaction, Mn dissolution, and irreversible gas release, and enhance structural stability. The cycling stability shows that the modified LRM cathode exhibits superior capacity retention (92.7 %) com-pared to that of the pristine LRM cathode (78.1 %) after 300 cycles at 1 C. This modification strategy heralds a useful paradigm for optimizing the cycling stability of LRM to promote their commercial application. (c) 2023 Elsevier B.V. All rights reserved.