Three-dimensional networked Na3V2(PO4)3/C composite as high-performance cathode for aqueous zinc-ion battery

Na3V2(PO4)3 (NVP) as one typical Na+ super ionic conductor (NASICON) is recognized as an ideal cathode material for ZIBs owing to its promising structural stability that facilitates long cycle, rich vacancies and channels facilitate storing metal ions, high operating potentials to ensure high energy density. However, it still faces poor cyclability and high-rate capacity. Here, three-dimensional networked Na3V2(PO4)3/C composite is synthesized by a microemulsion strategy with cetyltrimethyl ammonium bromide (CTAB) as the soft template, and the effect of aging temperature of microemulsion on their morphology and electrochemical performance is investigated. The Na3V2(PO4)3/C composite derived from the precursor reacted at 70 degrees C shows micrometer-size particles assembled by three-dimensional networked nanoplates, facilitating for ions transport and delivers the best electrochemical performance. It displays a high first capacity of 102.2 mAh g-1 with 42.3 mAh g-1 remained after 5000 stable cycles (capacity retention of 41.4%) at 5 C, a high capacity of 83.2 mAh g-1 even the current density is as high as 20 C, which is better than most of the reports.

Automated summary

A three-dimensional networked Na3V2(PO4)3/C composite was successfully synthesized using a microemulsion strategy, showing excellent electrochemical performance with high initial capacity, stable cycles, and high-rate capacity.