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Screen Printed Asymmetric Supercapacitors based on LiCoO 2 and Graphene Oxide*
Author(s) -
Dighe Ashish B.,
Dubal Deepak P.,
Holze Rudolf
Publication year - 2014
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.201400319
Subject(s) - supercapacitor , materials science , graphene , cyclic voltammetry , oxide , capacitance , electrode , electrolyte , chemical engineering , electrochemistry , separator (oil production) , nanotechnology , cobalt oxide , metallurgy , chemistry , physics , engineering , thermodynamics
Aiming at both high energy and power density, asymmetric supercapacitors with screen printed lithium cobalt oxide (LiCoO 2 ) and graphene oxide GO as electrode materials were assembled. LiCoO 2 was synthesized by a facile and inexpensive hydrothermal method, whereas GO was synthesized according to a modified Hummer's method. Both powders were coated on flexible stainless steel substrates using screen printing technology. Finally, asymmetric supercapacitors were assembled using LiCoO 2 as positive and GO as negative electrode with a porous polypropylene sheet as separator and an aqueous electrolyte solution of LiClO 4 . The electrochemical properties of this asymmetric cell were investigated by cyclic voltammetry and galvanostatic charge/discharge experiments. The asymmetric supercapacitor LiCoO 2 //GO could be cycled reversibly in the wide voltage region 0–1.5 V; it shows an impressive performance with an energy density of 19.2 Whkg –1 (based on the total mass of the active materials of the two electrodes). Importantly, this device exhibits an excellent long cycling life with 85 % specific capacitance retained after 1500 cycles. A demonstration cell could effectively light up an LED.