Synergetic lithium storage of bimetallic sulfide Co8FeS8/N-C dodecahedral nanocages with enhanced lithium-ion battery performance

In this paper, bimetallic sulfide Co 8 FeS 8 /N-C dodecahedral nanocages (DNCs) were synthesized by using ZIF-67 as a template through subsequent pyrolysis and sulfuration process. Co 8 FeS 8 nanoparticles are embedded carbon framework, which has porous hollow interior and conductive N-doped carbon matrix. When the Co 8 FeS 8 /N-C DNCs were applied as anode materials in lithium-ion battery, the bimetallic sulfide composites realize high reversible capacity (396 mA h g −1 at 0.5 A g −1 after 400 cycles) and excellent rate capability (349 mA h g −1 at 5.0 A g −1 ). Meanwhile, Co 8 FeS 8 /N-C DNCs also have superior cycle performance (308 mA h g −1 at 5.0 A g −1 after 1000 cycles). The remarkable properties are attributed to the synergy effect of bimetallic sulfide and the special polyhedral hollow structure with the conductive N-dopped mesoporous carbon.