Doping stabilized Li3V2(PO4)3 cathode for high voltage, temperature enduring Li-ion batteries

Structural and stoichiometric alterations in cathode materials with high intercalation voltages have been a bottleneck for next generation lithium ion batteries. Moreover, structure damage with the slightest of temperature elevation is predominant in known cathode systems. Monoclinic Li3V2(PO4)(3)(LVP) with high intercalation voltage (> 4.0 V) is a potential high-power cathode for lithium ion batteries owing to extraordinary stability of the phosphate anion framework. However, severe vanadium dissolution and lattice re-arrangement remains the biggest nuisance. Modification of electron conduction pathways by doping LVP lattice with Cr3+ is studied here and the efficacy of Cr3+ to stabilize the structure is understood. Vacant d-orbital sites in Cr3+ promote de-localization of electrons suppressing disproportionation and hence vanadium dissolution resulting in improved electrochemical performance for robust cycling conditions. Significant enhancement in specific capacity retention (from 26% to 84%) and improved cycle life of 400 high power cycles was observed on doping suggesting excellent performance of the cathode at high temperature (60 degrees C) environments.