Using glass defect engineering to obtain order?disorder transformation in cathode for high specific capacity lithium ion battery

Vanadium-based glass shows high electronic conductivity without grain boundaries. It easily undergoes structural microcrack defects during fabrication using the melt-quenching method resulting in voids that affect its properties. This paper demonstrates that the cathode material obtained by nanocrystals precipitated by longcycle electric fields are identical with those obtained by the heat treatment method. V2O5-Li3PO4 (VP) glass precipitates nanocrystals of Li3P and Li0.3V2O5 under heat treatment at 340 ?C. It showed a prominent specific capacity of 269.4 mAh.g? 1 in the first cycle at a current density of 50 mA.g? 1, and 227.4 mAh.g? 1 after 50 cycles with a retention rate of 86.3%, as the cathode of a lithium ion battery. Thermal field-controlled VP glass allows selective crystallization of nanocrystal of Li3P and Li0.3V2O5, which promote conductivity and charge transfer and significantly enhance the electrode reaction kinetics. Through ex-situ TEM, DSC, XRD and XPS, it was observed that discharge/charge caused disordered transitions in the amorphous VP, leading to the formation of nanocrystals of Li3P and Li0.3V2O5 after 100 cycles. Amorphous glass electrode material as a high-energy unstable state, has same tendency of precipitation of crystals to become stable under different treatment methods with long electric field cycles and thermal field induction.

Automated summary

The study demonstrates that cathode materials obtained by nanocrystals precipitated through long-cycle electric fields and heat treatment methods are identical, which can enhance conductivity and charge transfer rate, improving electrode reaction kinetics.