▎ 摘　　要

Nanoclay assisted electrochemical exfoliation was developed to in-situ form functionalized graphene electrode materials from pencil core with different ratios of graphite and clay. This method made a positive transformation from solid graphite to graphene colloidal solution, which can be used to construct binder- and additive-free thin-film electrodes. Exfoliated graphene can be served as both conductive current collector (film resistance of 33 5)/square) and electrode materials. Graphene thin-film electrodes from pencil cores displayed higher capacity of 224 than 80 mA h/g of that from pure graphite. The electrochemical performance can be controlled by the ratio of graphite and clay and the oxidation reaction of surface oxygen functional groups. The described nanoclay-assisted electrochemical oxidation route shows great potential for the synthesis of functionalized graphene electrode materials for high conductive thin-film lithium ion batteries and supercapacitors. (C) 2016 Elsevier Inc. All rights reserved.