Enhanced lithium ion storage in nanoimprinted carbon

Disordered carbons processed from polymers have much higher theoretical capacity as lithium ion battery anode than graphite, but they suffer from large irreversible capacity loss and have poor cyclic performance. Here, a simple process to obtain patterned carbon structure from polyvinylpyrrolidone was demonstrated, combining nanoimprint lithography for patterning and three-step heat treatment process for carbonization. The patterned carbon, without any additional binders or conductive fillers, shows remarkably improved cycling performance as Li-ion battery anode, twice as high as the theoretical value of graphite at 98 cycles. Localized electrochemical strain microscopy reveals the enhanced lithium ion activity at the nanoscale, and the control experiments suggest that the enhancement largely originates from the patterned structure, which improves surface reaction while it helps relieving the internal stress during lithium insertion and extraction. This study provides insight on fabricating patterned carbon architecture by rational design for enhanced electrochemical performance