Grain size regulation for balancing cycle performance and rate capability of LiNi0.9Co0.055Mn0.045O2 single crystal nickel-rich cathode materials

Abstract It is challenging to balance the cyclability and rate capability of single crystal nickel-rich cathode materials (Ni > 0.8). Multicomponent oxides by spray pyrolysis shows potential as highly-reactive precursors to synthesize single crystal nickel-rich cathode at lower temperature, yet Ni2+ will severely inhibit particle growth when Ni content exceeds 0.9. Herein, lithium nitrate (LiNO3) with low melting point and strong oxidation is introduced as collaborate lithium salts for fabrication of well-dispersed submicron and micron single crystal LiNi0.9Co0.055Mn0.045O2 (NCM90) cathode without extra unit operation. By changing amount of LiNO3, particle size regulation is realized and cation disorder can be diminished. The as-prepared material with optimal content of 4 wt% LiNO3 (NCM90-4LN) displays the most appropriate particle size (1 μm) with approximately stoichiometric structure, and presents better kinetics characterization of lithium-ion diffusion (15% higher than NCM90) and good electrochemical performance with specific discharge capacity of 220.6 and 173.8 mAh g−1 at 0.1C and 10C at room temperature, respectively. This work broadens the conventional research methodology of size regulation for single crystal Ni-rich cathode materials and is indispensable for the development of designing principal of nickel-rich cathode materials for lithium-ion batteries.