.png){kind=icon}
.png){kind=icon}
Return
Selective core-shell doping enabling high performance 4.6 V-LiCoO2
.png){kind=icon}
PRE
AI
DOI：10.1016/j.jechem.2024.04.004.png)
.png){kind=icon}
Original request for help.png){kind=icon}
Share.png){kind=icon}
Save
Abstract
En 中文
Constructing robust surface and bulk structure is the prerequisite for realizing high performance high voltage LiCoO2 (LCO). Herein, we manage to synthesize a surface Mg -doping and bulk Al -doping coreshell structured LCO, which demonstrates excellent cycling performance. Half -cell shows 94.2% capacity retention after 100 cycles at 3.0-4.6 V (vs. Li/Li+) cycling, and no capacity decay after 300 cycles for fullcell test (3.0-4.55 V). Based on comprehensive microanalysis and theoretical calculations, the degradation mechanisms and doping effects are systematically revealed. For the undoped LCO, high voltage cycling induces severe interfacial and bulk degradations, where cracks, stripe defects, fatigue H2 phase, and spinel phase are identified in grain bulk. For the doped LCO, Mg -doped surface shell can suppress the interfacial degradations, which not only stabilizes the surface structure by forming a thin rock -salt layer but also significantly improves the electronic conductivity, thus enabling superior rate performance. Bulk Al -doping can suppress the lattice breathing effect and the detrimental H3 to H1-3 phase transition, which minimizes the internal strain and defects growth, maintaining the layered structure after prolonged cycling. Combining theoretical calculations, this work deepens our understanding of the doping effects of Mg and Al, which is valuable in guiding the future material design of high voltage LCO. (c) 2024 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.
Keywords:
Lithium-ion battery
Doping effect
Failure mechanism
High-voltage LiCoO2
Electron microscopy
Journal
IF:
14.9
Papers:
6.3K
Citations:
4.5W
Organization
View more organizations