Mitigating Lattice Distortion of High-Voltage LiCoO2 via Core-Shell Structure Induced by Cationic Heterogeneous Co-Doping for Lithium-Ion Batteries

• DOI: 10.1007/s40820-023-01269-1
• Publication Date: 2023-12-11T17:04:22Z
• Authors: Zezhou Lin; Ke Fan; Tiancheng Liu; Zhihang Xu; Gao Chen; Honglei Zhang; Hao Li; Xuyun Guo; Xi Zhang; Ye Zhu; Peiyu Hou; Haitao Huang
• Keywords: Heterogeneous co-doping; High-voltage stability; Technology; Core-shell structure; T; Lithium-ion battery; LiCoO2; 0210 nano-technology; Core–shell structure; Article; 0104 chemical sciences

Abstract Inactive elemental doping is commonly used to improve the structural stability of high-voltage layered transition-metal oxide cathodes. However, one-step co-doping strategy usually results in small grain size since low diffusivity ions such as Ti 4+ will be concentrated on boundaries, which hinders growth. In order synthesize large single-crystal cathodes, considering different diffusivities dopant ions, we propose a simple two-step multi-element fabricate core–shell structured LiCoO 2 (CS-LCO). current work, high-diffusivity Al 3+ /Mg 2+ occupy core while enrich shell layer. The -enriched layer (~ 12 nm) with Co/Ti substitution and stronger Ti–O bond gives rise less oxygen ligand holes. In-situ XRD demonstrates constrained contraction c -axis lattice parameter mitigated distortion. Under high upper cut-off voltage 4.6 V, CS-LCO maintains reversible capacity 159.8 mAh g −1 good retention ~ 89% after 300 cycles, reaches specific 163.8 at 5C. proposed can extended other pairs low- (Zr , Ta 5+ W 6+ etc.) cations (Zn Ni Fe for rational design advanced cathodes lithium-ion batteries.