Activated graphene as a cathode material for Li-ion hybrid supercapacitors.
Chemically activated graphene ('activated microwave expanded graphite oxide', a-MEGO) was used as a cathode material for Li-ion hybrid supercapacitors. The performance of a-MEGO was first verified with Li-ion electrolyte in a symmetrical supercapacitor cell. Hybrid supercapacitors were then constructed with a-MEGO as the cathode and with either graphite or Li(4)Ti(5)O(12) (LTO) for the anode materials. The results show that the activated graphene material works well in a symmetrical cell with the Li-ion electrolyte with specific capacitances as high as 182 F g(-1). In a full a-MEGO/graphite hybrid cell, specific capacitances as high as 266 F g(-1) for the active materials at operating potentials of 4 V yielded gravimetric energy densities for a packaged cell of 53.2 W h kg(-1).
Department of Mechanical Engineering and the Materials Science and Engineering Program, The University of Texas at Austin, 1 University Station, C2200, Austin, TX 78712-0292, USA.
Meryl D
MD
Stoller
Shanthi
S
Murali
Neil
N
Quarles
Yanwu
Y
Zhu
Jeffrey R
JR
Potts
Xianjun
X
Zhu
Hyung-Wook
HW
Ha
Rodney S
RS
Ruoff