Recent Advances of Mesoscale-Structured Cathode Materials for High Energy Density Lithium-Ion Batteries

To meet the demands for Li-ion batteries in consumer electronics and renewable technologies, Ni-high and Li-rich layered oxides are attracting significant research interests for their extraordinarily high reversible capacities and being environmentally benign. However, both Ni-high and Li-rich layered oxides undergo serious cation mixing, superficial structural instability, and undesirable voltage decay, thus resulting in unsatisfactory electrochemical performance, which may trade off their benefits. Herein, this spotlight article focuses on recent advances in the rational design, preparation, and modification of mesoscale materials to overcome the shortcomings of Ni-high and Li-rich layered oxides, including soft chemical method, sequential precipitation method, poly(vinylpyrrolidone) (PVP: PVP-K30 [(C6H9NO)(n)] (molecular mass: 44000-54000)) bridging coating method, etching-induced coating method, and near-equilibrium deposition method, etc. This work will provide a scientific basis in material design and synthetic strategies toward high-performance mesoscale-structured Ni-high and Li-rich layered oxides and lay an experimental foundation for their future applications.