Abstract
Integrated supercapacitors with extended operation voltage are important for high energy density storage devices. In this work, we develop a novel direct electrode deposition on separator (DEDS) process to fabricate graphene based integrated tandem supercapacitors for the first time. The DEDS process generates compact graphene-polyaniline electrodes directly on the separators to form integrated supercapacitors. The integrated graphene-polyaniline tandem supercapacitors demonstrate ultrahigh volumetric energy density of 52.5W h L-1 at power density of 6037W L-1 and excellent gravimetric energy density of 26.1 W h kg(-1) at power density of 3002 W kg(-1) with outstanding electrochemical stability for over 10,000 cycles. This study show great promises for the future development of integrated energy storage devices. (C) 2015 Published by Elsevier Ltd.