Sodium Ion Capacitor Using Pseudocapacitive Layered Ferric Vanadate Nanosheets Cathode
Qiulong Wei,
Yalong Jiang,
Xiaoshi Qian,
Liang Zhang,
Qidong Li,
Shuangshuang Tan,
Kangning Zhao,
Wei Yang,
Qinyou An,
Jinghua Guo,
Liqiang Mai
Affiliations
Qiulong Wei
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China; Department of Materials Science and Engineering, University of California Los Angeles, Los Angeles, CA 90095, USA
Yalong Jiang
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China
Xiaoshi Qian
Department of Materials Science and Engineering, University of California Los Angeles, Los Angeles, CA 90095, USA
Liang Zhang
Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
Qidong Li
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China
Shuangshuang Tan
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China
Kangning Zhao
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China
Wei Yang
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China
Qinyou An
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China; Corresponding author
Jinghua Guo
Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
Liqiang Mai
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China; Corresponding author
Summary: Sodium ion capacitors (SICs) are designed to deliver both high energy and power densities at low cost. Electric double-layer capacitive cathodes are typically used in these devices, but they lead to very limited capacity. Herein, we apply a pseudocapacitive layered ferric vanadate (Fe-V-O) as cathode to construct non-aqueous SICs with both high energy and power densities. The Fe-V-O nanosheets cathode displays remarkable rate capability and cycling stability. The pseudocapacitive sodium storage mechanism of Fe-V-O, with over 83% of total capacity from capacitive contribution, is confirmed by kinetics analysis and ex situ characterizations. The capacitive-adsorption mechanism of hard carbon (HC) anode is demonstrated, and it delivers excellent rate capability. Based on as-synthesized materials, the assembled HC//Fe-V-O SIC delivers a maximum energy density of 194 Wh kg−1 and power density of 3,942 W kg−1. Our work highlights the advantages of pseudocapacitive cathodes for achieving both high energy and power densities in sodium storage devices. : Electrochemical Energy Storage; Energy Materials; Nanoelectrochemistry Subject Areas: Electrochemical Energy Storage, Energy Materials, Nanoelectrochemistry
