New high capacity cathode materials for rechargeable Li-ion batteries: Vanadate-borate glasses

Abstract

V2O5 based materials are attractive cathode alternatives due to the many oxidation state switches of vanadium bringing about a high theoretical specific capacity. However, significant capacity losses are eminent for crystalline V2O5 phases related to the irreversible phase transformations and/or vanadium dissolution starting from the first discharge cycle. These problems can be circumvented if amorphous or glassy vanadium oxide phases are employed. Here, we demonstrate vanadate-borate glasses as high capacity cathode materials for rechargeable Li-ion batteries for the first time. The composite electrodes of V2O5 - LiBO2 glass with reduced graphite oxide (RGO) deliver specific energies around 1000 Wh/kg and retain high specific capacities in the range of ∼ 300 mAh/g for the first 100 cycles. V2O5 - LiBO2 glasses are considered as promising cathode materials for rechargeable Li-ion batteries fabricated through rather simple and cost-efficient methods.