High pressure materials for energy storage. The case of V2O5

The high pressure polymorph of V2O5 is investigated as example of a high-pressure material (HP-V2O5) with potential applications in electrochemical devices, such as lithium batteries. HP-V2O5 reversibly intercalates up to 2 lithium ions down to 1 Volt vs Li+/Li. The typical voltage-composition profile of HP-V2O5 shows distinct features than that of the ambient pressure polymorph, AP-V2O5. Remarkably, the specific capacity retention with cycling of HP-V2O5 // Li cells (250 Ah/Kg at a C/3.5 rate) is comparable to that of the ambient pressure polymorph. Furthermore, the measured resistivities at room temperature (10000 Ωcm in AP and 400 Ωcm in HP) reveal that HP-V2O5 is a better electronic conductor than AP-V2O5. The enhanced electronic conductivity of HP-V2O5 is an advantage for electrochemical applications.