A three-in-one engineering strategy to achieve LiNi0.8Co0.1Mn0.1O2 cathodes with enhanced high-voltage cycle stability and high-rate capacities towards lithium storage.

Recently, the Ni-rich layered LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) is established as a promising cathode material for next-generation lithium-ion batteries (LIBs). However, it always suffers from severe bulk structural and interfacial degradation during electrochemical operation. To well address the issues, herein, a three-in-one engineering strategy is devised to construct a stable Nb-doped full concentration-gradient NCM811 coated with rhombohedral LiNbO 3 (denoted as N-FCG-NCM811@LNO). In the strategy, each secondary particle possesses a Ni-rich core and a Co/Mn-rich outer surface, along with the Li+-conductive LNO coating layer and surface gradient Nb doping. It is the synergistic contributions from three-aspect design (i.e. , FCG construction, surface coating and heteroatom doping) that renders NCM811 cathodes with stable crystalline structure and surface, mitigated microcracks, accelerated Li+ diffusion kinetic, and suppressed interfacial phase transition over cycling. The optimum N-FCG-NCM811@LNO achieves the improved capacity retention at high cut-off voltages (∼85.1% after 300 cycles between 3.0 and 4.4 V, and ∼80.5% after 200 cycles between 3.0 and 4.5 V both at 1C rate) and better high-rate capability (∼162.4 mAh g−1 at 10C). More meaningfully, the instructive electrode design concept here can be extended to other Ni-rich cathodes for high-energy/power LIBs via the simple yet scalable fabrication process. • A three-in-one engineering strategy is devised to construct N-FCG-NCM811@LNO. • The FCG design accommodates anisotropic internal strain and ensures bulk stability. • LNO coating favors Li + diffusion kinetic and minimizes surf-/interfacial decay. • Nb doping reduces cation mixing degree/phase transitions and microcracks in cycles. • The optimum cathode achieves superb high-rate capability and capacity retention. [ABSTRACT FROM AUTHOR]