Mechanistic Origin of Capacity Limitation in Sidorenkite‐Type Na3‐xFe(PO4)(CO3) Carbonophosphate Cathodes for Na‐Ion Batteries
New classes of materials are required for sodium ion batteries (SIBs) to compete with their Li‐counterpart. Sidorenkite‐type carbonate‐phosphate cathodes, such as Na3‐xFe(PO4)(CO3), were predicted to deliver high capacities based on two electron reactions. However, experiments consistently only access one of the predic...