Exceptional rate performance of functionalized carbon nanofiber anodes containing nanopores created by (Fe) sacrificial catalyst

Exceptional capacities and excellent rate performance have been achieved by anodes made from electrospun carbon nanofibers (CNFs) that possess synergies of (i) functionalization with carbonyl and carboxyl groups, (ii) presence of nanopores and (iii) embedded graphene layers. The Fe precursor incorporated into the polyacrylonitrile melt functions as both catalyst for graphitization and sacrificial phases. CNFs are functionalized and nanopores surrounded by graphene layers are simultaneously created during the chemical etching of Fe₃C particles from the CNFs. The pore size and volume could be tuned by controlling the Fe precursor content. Both the functional groups and nanopores are accessible to Li ions, and the satisfactory electrical conductivity arising from graphitization allows fast transfer of electrons. Remarkable capacities of 983 and 318mAhg^-1 are obtained when discharged at 100 and 3000mAg^-1, respectively, along with excellent capacity retention after 100 cycles.