Mechanically and chemically robust ultrahigh-Ni cathodes enabled by localized cation disorder design
Yijun Song, Bo Wang, Yongpeng Cui, Pengyun Liu, Xiuli Gao, Xuejin Li, Lei Zhu, Qingzhong Xue, Yongfu Tang, Wei Xing
Abstract
Layered oxide cathodes play a crucial role in developing high-energy-density Li-ion batteries. However, limited by weak interlayer support and poor oxygen stability, the ordered structure is easily transformed into a dense disordered structure, thus limiting their cycle life. Here we show that constructing a localized cation disorder (LCD) structure by chemically inducing treatment can radically address the mechanical-chemical coupling-induced structural degradation in ultrahigh-Ni cathodes. The LCD structure is proved to function as a steady-state supporting nanodomain, not only effectively enhancing the collective mechanical stability, especially avoiding the collapse of the Li-ion diffusion channel, but also enhancing the lattice oxygen framework stability by reducing charge compensation and improving electronic conductivity. As a result, the ultrahigh-Ni cathode with an LCD structure demonstrates remarkable capacity retention and excellent rate performance. This work highlights the effectiveness of localized structural design in addressing the mechanical and chemical instabilities for advanced oxide cathodes.