LiMPO4 and Li2MPO4F cathode materials: synthesis, morphology and electrochemical characteristics

The cathode is one of the key components responsible for the capacity of a lithium-ion battery. The presented review examines structural features and electrochemical characteristics of LiMPO4 and Li2MPO4F materials. In the literature, prototypes of lithium all-solid-state batteries only with LiFePO4 and lithium-ion solid electrolytes have been presented and studied. These cells show capacities in the range from 100 to 160 mA · h/g, which is comparable to lithium-ion batteries with liquid electrolyte. Li2MPO4F cathodes possess a high theoretical capacity of ~ 280 m · Ah/g and a theoretical energy density of ~ 1435 W · h/kg. However, the electrochemical study of Li2MPO4F fluorophosphates is limited due to the lack of a high-voltage liquid or polymer electrolyte. Thus, Li2MPO4F can be considered as a promising cathode for all-solid-state batteries with solid electrolytes that have a wider window of electrochemical stability.