Abstract
In recent years,sodium-ion batteries(SIBs)have emerged as a promising technology for energy storage systems(ESSs)because of the abundance and affordability of sodium.Recently,metal selenides have been studied as promising high-performance conversion-type anode materials in SIBs.Among them,nickel se-lenide(NiSe2)has received considerable attention due to its high theoretical capacity of 495 mAh g-1 and conductivity.However,it still suffers from poor cycling stability because of the low electrochemical reactivity,large volume expansion,and structural instability during cycles.To address these challenges,NiSe2 nanoparticles encapsulated in N-doped graphitic carbon fibers(NiSe2@NGCF)were synthesized by using ZIF-8 as a template.NiSe2@NGCF showed a high discharge capacity of 558.3 mAh g-1 with a fading rate of 0.14％per cycle after 200 cycles at 0.5 A g-1 in 0.01-3.0 V.At a very high current density of 5 A g-1,the capacity still displayed excellent long-term cycle life with a discharge capacity of 406.1 mAh g-1 with a fading rate of 0.016％per cycle after 3000 cycles.The mechanism of the excellent electrochem-ical performance of NiSe2@NGCF was thoroughly investigated by ex-situ XRD,TEM,and SEM analyses.Furthermore,NiSe2@NGCF//Na3V2(PO4)3 full-cell also delivered an excellent reversible capacity of 378.7 mAh g-1 at 0.1 A g-1 after 50 cycles,demonstrating its potential for practical application in SIBs.
基金项目
Dong-A University research fund()
NETL
NSTL
万方数据