Approaching the capacity limit of lithium cobalt oxide in lithium ion batteries via lanthanum and aluminium doping. (November 2018)

• Record Type: Journal Article
• Authors: Liu, Qi; Su, Xin; Lei, Dan; Qin, Yan; Wen, Jianguo; Guo, Fangmin; Wu, Yimin; Rong, Yangchun; Kou, Ronghui; Xiao, Xianghui; Aguesse, Frederic; Bareño, Javier; Ren, Yang; Lu, Wenquan; Li, Yangxing
• Is Part Of: Nature energy. Volume 3:Number 11(2018)
• Page Start: 936
• Page End: 943
• Publication Date: 2018-11
• Subjects: Power resources -- Periodicals; Energy development -- Periodicals; Renewable energy sources -- Periodicals; Energy policy -- Periodicals; Electric power systems -- Periodicals; 333.7905
• DOI: 10.1038/s41560-018-0180-6
• Languages: English
• ISSNs: 2058-7546

Abstract

Abstract Lithium cobalt oxides (LiCoO2 ) possess a high theoretical specific capacity of 274 mAh g–1 . However, cycling LiCoO2 -based batteries to voltages greater than 4.35 V versus Li/Li+ causes significant structural instability and severe capacity fade. Consequently, commercial LiCoO2 exhibits a maximum capacity of only ~165 mAh g–1 . Here, we develop a doping technique to tackle this long-standing issue of instability and thus increase the capacity of LiCoO2 . La and Al are concurrently doped into Co-containing precursors, followed by high-temperature calcination with lithium carbonate. The dopants are found to reside in the crystal lattice of LiCoO2, where La works as a pillar to increase thec axis distance and Al as a positively charged centre, facilitating Li+ diffusion, stabilizing the structure and suppressing the phase transition during cycling, even at a high cut-off voltage of 4.5 V. This doped LiCoO2 displays an exceptionally high capacity of 190 mAh g–1, cyclability with 96% capacity retention over 50 cycles and significantly enhanced rate capability. Lithium cobalt oxides are used as a cathode material in batteries for mobile devices, but their high theoretical capacity has not yet been realized. Here, the authors present a doping method to enhance diffusion of Li ions as well as to stabilize structures during cycling, leading to impressive electrochemical performance.