title: Na(+) intercalation pseudocapacitance in graphene-coupled titanium oxide enabling ultra-fast sodium storage and long-term cycling.
abstract: Sodium-ion batteries are emerging as a highly promising technology for large-scale energy storage applications. However, it remains a significant challenge to develop an anode with superior long-term cycling stability and high-rate capability. Here we demonstrate that the Na(+) intercalation pseudocapacitance in TiO2/graphene nanocomposites enables high-rate capability and long cycle life in a sodium-ion battery. This hybrid electrode exhibits a specific capacity of above 90 mA h g(-1) at 12,000 mA g(-1) (∼36 C). The capacity is highly reversible for more than 4,000 cycles, the longest demonstrated cyclability to date. First-principle calculations demonstrate that the intimate integration of graphene with TiO2 reduces the diffusion energy barrier, thus enhancing the Na(+) intercalation pseudocapacitive process. The Na-ion intercalation pseudocapacitance enabled by tailor-deigned nanostructures represents a promising strategy for developing electrode materials with high power density and long cycle life.
authors.affiliation: State Key Laboratory of Materials Processing and Die &Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Chaoji
authors.initials: C
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Materials Processing and Die &Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Yanwei
authors.initials: Y
authors.lastname: Wen
authors.affiliation: State Key Laboratory of Materials Processing and Die &Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Xianluo
authors.initials: X
authors.lastname: Hu
authors.affiliation: Department of Chemistry, Oregon State University, Corvallis, Oregon 97331-4003, USA.
authors.forename: Xiulei
authors.initials: X
authors.lastname: Ji
authors.affiliation: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, WUT-Harvard Joint Nano Key Laboratory, Wuhan University of Technology, Wuhan 430070, China.
authors.forename: Mengyu
authors.initials: M
authors.lastname: Yan
authors.affiliation: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, WUT-Harvard Joint Nano Key Laboratory, Wuhan University of Technology, Wuhan 430070, China.
authors.forename: Liqiang
authors.initials: L
authors.lastname: Mai
authors.affiliation: State Key Laboratory of Materials Processing and Die &Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Pei
authors.initials: P
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Materials Processing and Die &Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Shan
authors.affiliation: State Key Laboratory of Materials Processing and Die &Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Yunhui
authors.initials: Y
authors.lastname: Huang