title: Li3V2(PO4)3 encapsulated flexible free-standing nanofabric cathodes for fast charging and long life-cycle lithium-ion batteries.
abstract: Lithiated transition metal phosphates with large theoretical capacities have emerged as promising cathode materials for rechargeable lithium-ion batteries. However, the poor kinetic properties caused by their low intrinsic electronic and ionic conductivity greatly hinder their practical applications. In this work, we demonstrate a novel strategy to prepare monoclinic lithium vanadium phosphate nanoparticles implanted in carbon nanofibers as the cathodes of Li-ion cells with high capacity, flexibility, long cycle stability and significantly improved high-rate performance. The composite nanofibers were obtained by electrospinning using polyacrylonitrile and Li3V2(PO4)3 nanoparticles, followed by annealing and coating with a thin layer of carbon by plasma enhanced chemical vapor deposition. The Li3V2(PO4)3 nanocrystals with the monoclinic phase were uniformly distributed in the composite nanofibers. The electrochemical performances of the as-prepared binder-free fibrous cathodes were characterized by potentiostatic and galvanostatic tests. At the rate of 0.5 C in the range of 3.0-4.3 V, the composite displayed an initial discharge capacity of 128 mA h g(-1) (96.2% of the theoretical capacity). A discharge capacity of 120 mA h g(-1) was observed even at a high rate of 10 C, and a capacity retention of 98.9% was maintained after 500 cycles at 5 C, indicating excellent high-rate capability and capacity retention. Compared to the control samples without a carbon outer-layer, the composite nanofibers with carbon coating demonstrated much better electrochemical performances. It indicates that the carbon coating can further protect the structural integrity of nanofabric electrodes during the charge/discharge processes without hindering the Li-ion mobility and also can prevent undesired side reactions with an electrolyte, thus greatly improving the rate performance and cyclic stability of the cathode.
authors.affiliation: Key Laboratory of Mesoscopic Chemistry of MOE and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China. zhongjin@nju.edu.cn and Key Laboratory of MEMS of the Ministry of Education, Department of Physics, Southeast University, Nanjing 210096, China. xuqingyu@seu.edu.cn.
authors.forename: Pingping
authors.initials: P
authors.lastname: Sun
authors.affiliation: Key Laboratory of Mesoscopic Chemistry of MOE and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China. zhongjin@nju.edu.cn and College of Chemistry, Chemical Engineering and Materials Science, Zaozhuang University, Zaozhuang, 277160, China.
authors.forename: Xueying
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Mesoscopic Chemistry of MOE and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China. zhongjin@nju.edu.cn.
authors.forename: Renpeng
authors.initials: R
authors.lastname: Chen
authors.affiliation: Key Laboratory of Mesoscopic Chemistry of MOE and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China. zhongjin@nju.edu.cn.
authors.forename: Tao
authors.initials: T
authors.lastname: Chen
authors.affiliation: Key Laboratory of Mesoscopic Chemistry of MOE and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China. zhongjin@nju.edu.cn.
authors.forename: Lianbo
authors.initials: L
authors.lastname: Ma
authors.affiliation: Key Laboratory of MEMS of the Ministry of Education, Department of Physics, Southeast University, Nanjing 210096, China. xuqingyu@seu.edu.cn.
authors.forename: Qi
authors.initials: Q
authors.lastname: Fan
authors.affiliation: Key Laboratory of Mesoscopic Chemistry of MOE and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China. zhongjin@nju.edu.cn.
authors.forename: Hongling
authors.initials: H
authors.lastname: Lu
authors.affiliation: Key Laboratory of Mesoscopic Chemistry of MOE and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China. zhongjin@nju.edu.cn.
authors.forename: Yi
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Key Laboratory of Mesoscopic Chemistry of MOE and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China. zhongjin@nju.edu.cn and College of Engineering and Applied Sciences, Nanjing University, Nanjing, 210093, China.
authors.forename: Zuoxiu
authors.initials: Z
authors.lastname: Tie
authors.affiliation: Key Laboratory of Mesoscopic Chemistry of MOE and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China. zhongjin@nju.edu.cn.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Jin
authors.affiliation: Key Laboratory of MEMS of the Ministry of Education, Department of Physics, Southeast University, Nanjing 210096, China. xuqingyu@seu.edu.cn.
authors.forename: Qingyu
authors.initials: Q
authors.lastname: Xu
authors.affiliation: Key Laboratory of Mesoscopic Chemistry of MOE and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China. zhongjin@nju.edu.cn and Department of Chemistry, Duke University, Durham, North Carolina 27708, USA. j.liu@duke.edu.
authors.forename: Jie
authors.initials: J
authors.lastname: Liu