title: Self-assembling synthesis of free-standing nanoporous graphene-transition-metal oxide flexible electrodes for high-performance lithium-ion batteries and supercapacitors.
abstract: The synthesis of nanoporous graphene by a convenient carbon nanofiber assisted self-assembly approach is reported. Porous structures with large pore volumes, high surface areas, and well-controlled pore sizes were achieved by employing spherical silica as hard templates with different diameters. Through a general wet-immersion method, transition-metal oxide (Fe3O4, Co3O4, NiO) nanocrystals can be easily loaded into nanoporous graphene papers to form three-dimensional flexible nanoarchitectures. When directly applied as electrodes in lithium-ion batteries and supercapacitors, the materials exhibited superior electrochemical performances, including an ultra-high specific capacity, an extended long cycle life, and a high rate capability. In particular, nanoporous Fe3O4-graphene composites can deliver a reversible specific capacity of 1427.5 mAh g(-1) at a high current density of 1000 mA g(-1) as anode materials in lithium-ion batteries. Furthermore, nanoporous Co3O4-graphene composites achieved a high supercapacitance of 424.2 F g(-1) . This work demonstrated that the as-developed freestanding nanoporous graphene papers could have significant potential for energy storage and conversion applications.
authors.affiliation: Centre for Clean Energy Technology, School of Chemistry and Forensic Science, University of Technology Sydney, NSW 2007 (Australia).
authors.forename: Xiaodan
authors.initials: X
authors.lastname: Huang
authors.forename: Bing
authors.initials: B
authors.lastname: Sun
authors.forename: Shuangqiang
authors.initials: S
authors.lastname: Chen
authors.forename: Guoxiu
authors.initials: G
authors.lastname: Wang
keywords: electrochemistry; graphene; nanostructures; supercapacitors; transition metals