Ultra‐stable carbon‐coated sodium vanadium phosphate as cathode material for sodium‐ion battery
Di Wang, Peng Cai, Guoqiang Zou, Hongshuai Hou, Xiaobo Ji, Ye Tian, Zhen Long
Abstract
Abstract Based on the excellent sodium ion mobility of sodium superionic conductor structures, Na 3 V 2 (PO 4 ) 3 materials have become promising cathode materials in sodium‐ion batteries (SIBs). However, inadequate electronic transport of Na 3 V 2 (PO 4 ) 3 limits the cycling stability and rate performances in SIBs. In this work, high‐performance conductive carbon‐coated Na 3 V 2 (PO 4 ) 3 materials are obtained via a simple and facile ball‐milling assisted solid‐state method by utilizing citric acid as carbon sources. The carbon‐coated composite electrodes display a high initial specific capacity of 111.6 mAh·g −1 , and the specific capacity could retention reach 92.83% after 100 cycles at 1C with the high coulombic efficiency (99.95%). More importantly, the capacity of conductive carbon‐coated nano‐sized Na 3 V 2 (PO 4 ) 3 can remain 48.5 mAh·g −1 at 10C after 3000 cycles (initial capacity of 101.2 mAh·g −1 ). At the same time, high coulombic efficiency (near 100%) has little decay even at a high rate of 20C during 1000 cycles, demonstrating the excellent cycling stability and remarkable rate performances, and showing potential in large‐scale productions and applications.