Electrode materials for aqueous multivalent metal-ion batteries: Current status and future prospect

In recent years, the pursuit of high-efficiency electrochemical storage technology, the multivalent metal-ion batteries (MIBs) based on aqueous electrolytes have been widely explored by researchers because of their safety, environmental friendliness, abundant reserves and low price, and especially the merits in energy and power densities. This review firstly expounds on the problems existing in the electrode materials of aqueous multivalent MIBs (Zn2+, Mg2+, Al3+, Ca2+), from the classical inorganic materials to the emerging organic compounds, and then summarizes the design strategies in bulk and interface structure of electrodes with favorable kinetics and stable cycling performance, especially laying the emphasis on the charge storage mechanism of cathode materials and dendrite-free Zinc anode from the aspect of electrolyte optimization strategies, which can be extended to other aqueous multivalent MIBs. Ultimately, the possible development directions of the aqueous multivalent MIBs in the future are provided, anticipating to provide a meaningful guideline for researchers in this area.