▎ 摘　　要

A Li-ion capacitor (LIC), typically composed of a pre-lithiated negative electrode and an activated-carbon positive electrode, can provide high energy and power density. In this work, we compare the electrochemical performances of pre-lithiated graphene nanosheets and conventional graphite as negative electrode materials for LICs. The LICs employing pre-lithiated graphene nanosheets show a specific capacitance of 168.5 F g(-1) with 74% capacitance retention at 400 mA g(-1) after 300 cycles. Moreover, the capacitors deliver a maximum power density of 222.2 W kg(-1) at an energy density of 61.7 Wh kg(-1) operated in the voltage range of 2.0-4.0 V. Therefore, pre-lithiated graphene nanosheets are promising negative electrode materials for high power LICs. (C) 2014 Elsevier B.V. All rights reserved.