作者
Xiang Liu,Gui‐Liang Xu,Venkata Surya Chaitanya Kolluru,Chen Zhao,Qingtian Li,Xinwei Zhou,Yuzi Liu,Liang Yin,Zengqing Zhuo,Amine Daali,Jingjing Fan,Wenjun Liu,Yang Ren,Wenqian Xu,Junjing Deng,Inhui Hwang,Dongsheng Ren,Xuning Feng,Cheng‐Jun Sun,Ling Huang,Tao Zhou,Ming Du,Zonghai Chen,Shi‐Gang Sun,Maria K. Y. Chan,Wanli Yang,Minggao Ouyang,Khalil Amine
摘要
Oxygen redox at high voltage has emerged as a transformative paradigm for high-energy battery cathodes such as layered transition-metal oxides by offering extra capacity beyond conventional transition-metal redox. However, these cathodes suffer from voltage hysteresis, voltage fade and capacity drop upon cycling. Single-crystalline cathodes have recently shown some improvements, but these challenges remain. Here we reveal the fundamental origin of oxygen redox instability to be from the domain boundaries that are present in single-crystalline cathode particles. By investigating single-crystalline cathodes with different domain boundaries structures, we show that the elimination of domain boundaries enhances the reversible lattice oxygen redox while inhibiting the irreversible oxygen release. This leads to significantly suppressed structural degradation and improved mechanical integrity during battery cycling and abuse heating. The robust oxygen redox enabled through domain boundary control provides practical opportunities towards high-energy, long-cycling, safe batteries. Oxygen redox instability at high voltages hinders the application of high-energy battery cathodes. Here the authors report that elimination of domain boundaries in single-crystal cathodes improves the redox stability and consequently the electrochemical performance in extended high-voltage cycling.