Ultra-stable carbon-coated sodium vanadium phosphate as cathode material for sodium-ion battery

Based on the excellent sodium ion mobility of sodium superionic conductor structures, Na3V2(PO4)(3) materials have become promising cathode materials in sodium-ion batteries (SIBs). However, inadequate electronic transport of Na3V2(PO4)(3) limits the cycling stability and rate performances in SIBs. In this work, high-performance conductive carbon-coated Na3V2(PO4)(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 center dot 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 Na3V2(PO4)(3) can remain 48.5 mAh center dot g(-1) at 10C after 3000 cycles (initial capacity of 101.2 mAh center dot 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.

Automated summary

High-performance conductive carbon-coated Na3V2(PO4)(3) materials were successfully prepared via a simple and facile solid-state method, showing excellent cycling stability and rate performances in sodium-ion batteries. The carbon-coated composite electrodes exhibited high initial specific capacity and maintained high coulombic efficiency even at high rates, indicating great potential for large-scale productions and applications.