Simultaneous regulation of grain size and interface of single-crystal ultrahigh-nickel LiNi0.9Co0.055Mn0.045O2 via one-step Li2ZrO3 coating

Single-crystal ultrahigh-nickel LiNixCoyMn1-x-yO2 (NCM) materials are recognized for significant potential in the development of high-performance lithium-ion batteries, primarily owing to their higher energy density and superior cycling performance compared to polycrystalline counterparts. However, these materials require high calcination temperatures, suffer from significant lithium/nickel mixing, and face challenges in composition control. Although high-activity oxide precursors prepared via spray pyrolysis can reduce calcination temperatures, the smaller particle size of the resulting NCM materials intensifies interfacial side reactions. In this study, we addressed these challenges by coating LiNi0.9Co0.055Mn0.045O2 (NCM90) with Li2ZrO3 through low-temperature annealing, which integrates grain size regulation and interface modification in one step. Morphology and structure analysis show that the applied coating increased the particle size from 0.3 μm to 0.75 μm, preserved a more reversible crystalline structure in the lithium-deficient state, and reduced the volumetric shrinkage of NCM during cycling. The initial discharge capacity (212 mAh/g at 0.1 C) and 100 cycle capacity retention (88 %) of the optimal material (Li2ZrO3 loading of 0.16 wt%) significantly exceeded those of unmodified NCM90 and C-NCM90 prepared from a commercial precursor. This proposed “two birds with one stone” strategy offers a promising approach for developing single-crystal ultrahigh-nickel cathode materials and, consequently, high-performance lithium-ion batteries.