Dual‐Ion Intercalation Chemistry Enabling Hybrid Metal‐Ion Batteries

To outline the role of dual-ion intercalation chemistry to reach sustainable energy storage, the present Review aimed to compare two types of batteries: widely accepted dual-ion batteries based on cationic and anionic co-intercalation versus newly emerged hybrid metal-ion batteries using the co-intercalation of cations only. Among different charge carrier cations, the focus was on the materials able to co-intercalate monovalent ions (such Li+ and Na+ , Li+ and K+ , Na+ and K+ , etc.) or couples of mono- and multivalent ions (Li+ and Mg2+ , Na+ and Mg2+ , Na+ and Zn2+ , H+ and Zn2+ , etc.). Furthermore, the Review was directed on co-intercalation materials composed of environmentally benign and low-cost transition metals (e. g., Mn, Fe, etc.). The effect of the electrolyte on the co-intercalation properties was also discussed. The summarized knowledge on dual-ion energy storage could stimulate further research so that the hybrid metal-ion batteries become feasible in near future.