ИСТИНА

Rechargeable Li-ion batteries exclusively power a huge variety of portable electronic devices, which can be spotted in our everyday life. In most cases, such a battery is fabricated with Li-containing layered oxide cathode materials, which can store much energy, however, lack thermal and structural stability as well as high-power performance. Polyanion or mixed anion cathode materials such as fluoride-phosphates AxMPO4F (A = Li, Na; M = V, Mn, Fe, Co, Ni; x = 1, 2), have recently gained much popularity and now are envisaged to occupy a large-scale applications. Within this class of materials, the nature of alkali and transition metals has a strong impact on the crystal structure adopted, which further determines electrochemical properties. A larger ionic radius compared to Li and Na and somewhat different crystal chemistry of K and Rb allow designing and stabilizing new frameworks for reversible ion de/intercalation. Here we report on novel vanadium-based AVPO4F (A = Li, K, Rb) cathode materials with a KTP-type framework for rechargeable batteries with high specific energy and excellent kinetics.