SU-8/MWCNT derived Electrospun Composite Carbon Nanofabric as a High Performance Anode Material for Lithium Ion Battery

Abstract

SU-8, an epoxy based negative photoresist was electrospun with a fixed amount of multiwall carbon nanotubes (MWCNT) added into it to form the long, uniform, and bead-free fibers. These composite electrospun fibers were then subjected to pyrolysis in inert atmosphere at 1173 K to yield carbon nanofibers with enhanced crystallinity as revealed by structural characterization. Although the morphology of the nanofibers before and after pyrolysis was found to be largely unaffected however there was a shrinkage of nearly 32% in the average fiber diameter upon pyrolysis. As-synthesized electrospun composite carbon nanofibers were then tested directly without adding a binder for their electrochemical performance as anode for lithium ion battery. A significantly higher reversible capacity of 1320 mAh/g was observed at 0.1 C-rate with excellent initial efficiency of 54%. Similarly at high C-rates also, electrochemical performance was found to be excellent primarily due to enhanced crystallinity with the addition of MWCNT and entangled morphology of electrospun carbon nanofibers.