Highly Dispersed Micrometer Nickel-Rich Single-Crystal Construction: Benefits of Supercritical Reconstruction during Hydrothermal Synthesis

The disordered volume effect of anisotropic primary particles during electrochemical processes is a key problem in the electrochemical instability of LiNiO2-based cathode materials. In this work, Ni0.8Co0.1Mn0.1(OH)2 precursors with a hexagonal morphology were synthesized via a hydrothermal method. Highly crystalline micrometer Ni-rich single-crystal LiNi0.8Co0.1Mn0.1O2 cathode materials with excellent dispersion were successfully prepared at a relatively lower calcination temperature and excess lithium ratio than those of conventional methods. When compared to traditional commercial Ni-rich polycrystalline cathodes, these single-crystal cathode materials had a better initial capacity of 186.2 mAh g–1 and an excellent capacity retention of ∼93.4% (2.8–4.3 V) after 100 cycles at 1 C. Moreover, monodispersed, micrometer- and submicrometer-sized Li-storage architectures shortened the Li+-diffusion distance and provided upgraded rate performance, achieving a capacity of 130.4 mAh g–1 at a rate of 10 C. Thus, the hydrothermal construction of a single-crystal precursor-assisted mild sintering strategy was effective for designing single-crystal Ni-rich Li-storage structures with good electrochemical properties.