Chemomechanically Stable Small Single‐crystal Mo‐doped LiNi0.6Co0.2Mn0.2O2 Cathodes for Practical 4.5 V‐class Pouch‐type Li‐ion Batteries

High voltage can cost-effectively boost energy density of Ni-rich cathodes based Li-ion batteries (LIBs), but compromises their mechanical, electrochemical and thermal-driven stability. Herein, a collaborative strategy (i.e., small single-crystal design and hetero-atom doping) is devised to construct a chemomechanically reliable small single-crystal Mo-doped LiNi_0.6 Co_0.2 Mn_0.2 O₂ (SS-MN6) operating stably under high voltage (≥4.5 V vs. Li/Li⁺ ). The substantially reduced particle size combined with Mo⁶⁺ doping absorbs accumulated localized stress to eradicate cracks formation, subdues the surface side reactions and lattice oxygen missing meanwhile, and improves thermal tolerance at highly delithiated state. Consequently, the SS-MN6 based pouch cells are endowed with striking deep cycling stability and wide-temperature-tolerance capability. The contribution here provides a promising way to construct advanced cathodes with superb chemomechanical stability for next-generation LIBs.