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 LiNi0.8Co0.1Mn0.1O2 (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 LiNbO3 (denoted as [email protected]). 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 [email protected] 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.