Interlayer Engineering of Preintercalated Layered Oxides as Cathode for Emerging Multivalent Metal-ion Batteries: Zinc and Beyond

Typical layered structures with large capacity have attracted much interest in lithium ion batteries and emerging post-lithium ion batteries. However, these typical layered oxides, including alpha-, delta-V2O5, delta-MnO2, and alpha-MoO3, have suffered poor electrical conductivity, severe structural deterioration, and sluggish diffusion kinetics during the repetitive charging/discharging process. In recent years, interlayer engineering of preintercalation strategies has offered effective solutions for solving these problems. Structural water molecules (H2O), monovalent alkali cations (Li+/Na+/K+) and ammonium ion (NH4+), multivalent alkali-earth cations (Mg2+/Ca2+/Ba2+) and aluminum ion (Al3+), various transition metal cations (Mn2+/Fe2+/Co2+/Ni2+/Cu2+/Zn2+/Ag+, etc.), and organic molecules (PANI/PEDOT/PEO, etc.) have been proved to be efficient "pillars" for stabilizing the fragile layered structure and enhanced diffusion kinetics. These prominent effects have boosted the developments of preintercalated layered structures for emerging multivalent metal-ion batteries, especially rechargeable aqueous zinc ion batteries (AZIBs). In this review, we have clarified the representative crystal structures, preparation methods, advanced characterization methods and corresponding mechanistic insights, and successful applications of these preintercalated layered oxides in multivalent metal-ion batteries.