A Long-Cycling Aqueous Zinc-Ion Pouch Cell: NASICON-Type Material and Surface Modification.

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, NASICON-type Na 3 V 2 (PO 4 ) 3 cathode that modified by a uniform carbon layer (NVP/C) is 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, Zn 2+ (de)intercalation mechanism in NVP cathode is determined by various ex-situ techniques. In addition, the Zn||NVP/C pouch cell is also assembled, delivering a high capacity of 89 mAhg -1 at 200 mA g -1 and exhibiting a superior long cycling stability.