Modifying Li@Mn6 Superstructure Units by Al Substitution to Enhance the Long‐Cycle Performance of Co‐Free Li‐Rich Cathode. Issue 37 (18th August 2021)

• Record Type: Journal Article
• Authors: Li, Zhibo; Li, Yiwei; Zhang, Mingjian; Yin, Zu‐Wei; Yin, Liang; Xu, Shenyang; Zuo, Changjian; Qi, Rui; Xue, Haoyu; Hu, Jiangtao; Cao, Bo; Chu, Mihai; Zhao, Wenguang; Ren, Yang; Xie, Lin; Ren, Guoxi; Pan, Feng
• Is Part Of: Advanced energy materials. Volume 11:Issue 37(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-08-18
• Subjects: Al substitution -- Co‐free Li‐rich cathodes -- Li@Mn 6 superstructure units -- Li‐ion batteries -- local structural modification; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.202101962
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: As one of the most promising cathodes for Li‐ion batteries, Li‐rich layered oxides suffer from low Coulombic efficiency, severe capacity fading, and voltage decay, which are related to the aggregated Li@Mn6 superstructure units. Herein, a Co‐free Li‐rich oxide Li[Li1/4 Mn1/2 Ni1/6 Al1/12 ]O2 through Al substitution of Co in Li[Li1/4 Mn1/2 Ni1/6 Co1/12 ]O2, is designed. Combining the average structural refinement with the detailed local structural/chemical analysis, it is found that the introduced Al ions occupy the Mn sites in Li@Mn6 superstructure units, which further induces the partial replacement of the central Li ions in Li@Mn6 units by Ni 2+ . The modified superstructure units stabilize the anionic framework and suppress structural degradation during long‐term cycling. A superior cyclability (a capacity retention of 91.4% after 500 cycles at 1 C) is achieved. This work not only deepens the understanding into the mechanism of Al substitution, but also provides a novel route to design high‐performance Li‐rich cathodes by modifying the local functional units. Abstract : The modification of Li@Mn6 superstructure units is implemented in a Co‐free Li‐rich layered oxide Li[Li1/4 Mn1/2 Ni1/6 Al1/12 ]O2 through Al substitution of Co, which exhibits a superior long‐term cyclability due to the suppressed structural degradation during long‐term cycling.