Crumpled graphene-molybdenum oxide composite powders: preparation and application in lithium-ion batteries.
Crumpled graphene-MoO2 composite powders are directly prepared by means of spray pyrolysis and from a stable graphene oxide colloidal solution in the presence of Mo ions. The crumpled graphene-MoO2 composite powders are transformed into MoO3 -based composite powders after post-treatment at 300 °C. The transmission electron microscopy and dot-mapping images of the post-treatment composite powders show uniform distribution of MoO3 nanocrystals in the crumpled graphene powders. The two typical D and G bands of graphene are observed at 1350 and 1590 cm(-1) , respectively, in the Raman spectrum of the graphene-MoO3 composite. In addition, the crumpled graphene-MoO3 powders exhibit superior electrochemical behavior compared to that of pure MoO3 as an anode material for lithium-ion batteries. The initial discharge capacities of the graphene-MoO3 composite and bare MoO3 powders at a current density of 2 A g(-1) are 1490 and 1225 mA h g(-1) , respectively. The capacity retention of the graphene-MoO3 composite is 87 % after the first cycle, whereas that of bare MoO3 is 47 %, as measured after 100 cycles. The reversible discharge capacity of the graphene-MoO3 composite decreases slightly from 1228 to 845 mA h g(-1) as the current density increases from 0.5 to 3 A g(-1) .
Department of Chemical Engineering, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701 (Korea), Fax: (+82) 2-4583504.
Seung Ho
SH
Choi
Yun Chan
YC
Kang
D011211:Electric Power Supplies; D004563:Electrochemistry; D006108:Graphite / Q000737:chemistry*; D008094:Lithium / Q000737:chemistry*; D008982:Molybdenum / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D011208:Powders
D010087:Oxides; D011208:Powders; C539565:molybdenum dioxide; D006108:Graphite; D008982:Molybdenum; D008094:Lithium
anode materials; electrochemistry; graphene; lithium-ion batteries; molybdenum oxide