title: Rational selection of amorphous or crystalline V2O5cathode for sodium-ion batteries.
abstract: Vanadium oxide (V2O5), as a potential positive electrode for sodium ion batteries (SIBs), has attracted considerable attention from researchers. Herein, amorphous and crystalline V2O5cathodes on a graphite paper without a binder and conductive additives have been synthesized via facile anodic electrochemical deposition following different heat treatments. Both the amorphous V2O5(a-V2O5) cathode and crystalline V2O5(c-V2O5) cathode show good rate cycling performance and long cycling life. After five rate cycles, the reversible capacities of both the cathodes were almost unchanged at different current densities from 40 to 5120 mA g-1. Long cycling tests with 10 000 cycles were carried out and the two cathodes exhibit excellent cycling stability. The c-V2O5cathode retains a high specific capacity of 54 mA h g-1after 10 000 cycles at 2560 mA g-1and can be charged within 80 s. Interestingly, the a-V2O5cathode possesses higher reversible capacities than the c-V2O5cathode at low current densities, whereas it is inversed at high current densities. The c-V2O5cathode shows faster capacity recovery from 5120 to 40 mA g-1than the a-V2O5cathode. When discharged at 80 mA g-1(long discharge time of 140 min) and charged at 640 mA g-1(short charge time of 17 min), the a-V2O5cathode shows a higher discharge capacity than its c-V2O5counterpart. The different electrochemical performance of a-V2O5and c-V2O5cathodes during various electrochemical processes can provide a rational selection of amorphous or crystalline V2O5cathode materials for SIBs in their practical applications to meet the variable requirements.
authors.affiliation: MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, PR China. jpzhao@hit.edu.cn liu88062321@163.com.
authors.forename: Shikun
authors.initials: S
authors.lastname: Liu
authors.affiliation: Center for Composite Materials, Harbin Institute of Technology, Harbin 150001, PR China. yaoli@hit.edu.cn.
authors.forename: Zhongqiu
authors.initials: Z
authors.lastname: Tong
authors.affiliation: MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, PR China. jpzhao@hit.edu.cn liu88062321@163.com.
authors.forename: Jiupeng
authors.initials: J
authors.lastname: Zhao
authors.affiliation: MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, PR China. jpzhao@hit.edu.cn liu88062321@163.com.
authors.forename: Xusong
authors.initials: X
authors.lastname: Liu
authors.affiliation: MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, PR China. jpzhao@hit.edu.cn liu88062321@163.com.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, PR China. jpzhao@hit.edu.cn liu88062321@163.com.
authors.forename: Xiaoxuan
authors.initials: X
authors.lastname: Ma
authors.affiliation: MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, PR China. jpzhao@hit.edu.cn liu88062321@163.com.
authors.forename: Caixia
authors.initials: C
authors.lastname: Chi
authors.affiliation: MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, PR China. jpzhao@hit.edu.cn liu88062321@163.com.
authors.forename: Yu
authors.initials: Y
authors.lastname: Yang
authors.affiliation: MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, PR China. jpzhao@hit.edu.cn liu88062321@163.com and Heilongjiang University of Science and Technology, Harbin 150022, PR China.
authors.forename: Xiaoxu
authors.initials: X
authors.lastname: Liu
authors.affiliation: Center for Composite Materials, Harbin Institute of Technology, Harbin 150001, PR China. yaoli@hit.edu.cn.
authors.forename: Yao
authors.initials: Y
authors.lastname: Li