Ni_(3)FeN anchored on porous carbon as electrocatalyst for advanced Li-S batteries

摘要

Lithium-sulfur(Li-S)battery is one of the newgeneration energy storage systems with great potential.However,the development of Li-S battery now is hampered by the shuttle effect and depressed redox kinetics.Herein,we report a composite of Ni_(3)FeN nanoparticles anchored in grid-like porous carbon(PC)spheres as an effective cathode electrocatalyst with simultaneous polysulfide trapping and rapid polysulfides conversion in Li-S battery.The multi-cavity structure of PC with high-efficiency encapsulation ability can significantly improve sulfur utilization and confinement.Furthermore,Ni_(3)FeN nanoparticles embedded in PC cavities render highly active catalytic sites to promote the redox conversion of solvated poly sulfide,as revealed by the electrochemical results.Moreover,the catalytic mechanism is further analyzed through density functional theory calculations and in-situ Fourier transform infrared analysis.As a result,PC@Ni_(3)FeN@S cathode delivers an outstanding capacity of 1294mAh·g^(-1)at 0.1C and low decay rates of 0.10%per cycle over 500 cycles at 0.5C.