A Review on the Energy Storage Mechanisms of Transition Metal Sulfide and Selenide Cathode Materials for Non‐Aqueous Aluminum Batteries

Non‐aqueous rechargeable Al batteries (RABs) have significant potential as sustainable energy storage technology as attention shifts toward the next generation of battery systems and away from the current Li reliance. Even though RABs can achieve high theoretical specific (2980 Ah kg −1 ) and volumetric (8046 mAh cm −3 ) capacities if they harness Al's three electron chemistry via Al 3+ intercalation, they are still falling short of their potential. Suitable cathodes are a bottleneck obstructing RAB's progress into industry along with the current lack of understanding of the underlying reaction mechanisms of the energy storage process including cation insertion and conversion mechanisms. This review will investigate the promising class of transition metal sulfide‐ and selenide‐based cathode materials for RABs and lay the foundations for uncovering the controlling factors behind their electrochemical processes. A systematic and critical literature investigation is carried out to identify contradictions and knowledge gaps to highlight promising research pathways with the aim of propelling researchers’ understandings of these systems, and hence, advancing the field of RABs.