Aqueous zinc-ion batteries (ZIBs) have become the highest potential energy storage system for large-scale applications owing to the high specific capacity, good safety and low cost. In this work, a NASICON-type Na3 V2 (PO4 )3 cathode modified by a uniform carbon layer (NVP/C) has been synthesized via a facile solid-state method and exhibited significantly improved electrochemical performance when working in an aqueous ZIB. Specifically, the NVP/C cathode shows an excellent rate capacity (e. g., 48 mAh g-1 at 1.0 A g-1 ). Good cycle stability is also achieved (e. g., showing a capacity retention of 88% after 2000 cycles at 1.0 A g-1 ). Furthermore, the Zn2+ (de)intercalation mechanism in the NVP cathode has been determined by various ex-situ techniques. In addition, a Zn||NVP/C pouch cell has been assembled, delivering a high capacity of 89 mAhg-1 at 0.2 A g-1 and exhibiting a superior long cycling stability.
Keywords: Na3V2(PO4)3; Zn-storage mechanism; aqueous zinc-ion batteries; long cycling stability; pouch cells.
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