title: Synthesis of SnO2 versus Sn crystals within N-doped porous carbon nanofibers via electrospinning towards high-performance lithium ion batteries.
abstract: The design of tin-based anode materials (SnO2 or Sn) has become a major concern for lithium ion batteries (LIBs) owing to their different inherent characteristics. Herein, particulate SnO2 or Sn crystals coupled with porous N-doped carbon nanofibers (denoted as SnO2/PCNFs and Sn/PCNFs, respectively) are fabricated via the electrospinning method. The electrochemical behaviors of both SnO2/PCNFs and Sn/PCNFs are systematically investigated as anodes for LIBs. When coupled with porous carbon nanofibers, both SnO2 nanoparticles and Sn micro/nanoparticles display superior cycling and rate performances. SnO2/PCNFs and Sn/PCNFs deliver discharge capacities of 998 and 710 mA h g(-1) after 140 cycles (at 100, 200, 500 and 1000 mA g(-1) each for 10 cycles and then 100 cycles at 100 mA g(-1)), respectively. However, the Sn/PCNF electrodes show better cycling stability at higher current densities, delivering higher discharge capacities of 700 and 550 mA h g(-1) than that of SnO2/PCNFs (685 and 424 mA h g(-1)) after 160 cycles at 200 and 500 mA g(-1), respectively. The different superior electrochemical performance is attributed to the introduction of porous N-doped carbon nanofibers and their self-constructed networks, which, on the one hand, greatly decrease the charge-transfer resistance due to the high conductivity of N-doped carbon fibers; on the other hand, the porous carbon nanofibers with numerous voids and flexible one-dimensional (1D) structures efficiently alleviate the volume changes of SnO2 and Sn during the Li-Sn alloying-dealloying processes. Moreover, the discussion of the electrochemical behaviors of SnO2vs. Sn would provide new insights into the design of tin-based anode materials for practical applications, and the current strategy demonstrates great potential in the rational design of metallic tin-based anode materials.
authors.affiliation: Center of Nanomaterials for Renewable Energy (CNRE), State Key Lab of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi'an Jiaotong University, Xi'an, China 710049. hongkang.wang@mail.xjtu.edu.cn.
authors.forename: Hongkang
authors.initials: H
authors.lastname: Wang
authors.affiliation: Center of Nanomaterials for Renewable Energy (CNRE), State Key Lab of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi'an Jiaotong University, Xi'an, China 710049. hongkang.wang@mail.xjtu.edu.cn and Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an, China 710049. g.yang@mail.xjtu.edu.cn.
authors.forename: Xuan
authors.initials: X
authors.lastname: Lu
authors.affiliation: Center for Biomedical Engineering and Regenerative Medicine, Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China 710049. baoling@mail.xjtu.edu.cn.
authors.forename: Longchao
authors.initials: L
authors.lastname: Li
authors.affiliation: Center of Nanomaterials for Renewable Energy (CNRE), State Key Lab of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi'an Jiaotong University, Xi'an, China 710049. hongkang.wang@mail.xjtu.edu.cn.
authors.forename: Beibei
authors.initials: B
authors.lastname: Li
authors.affiliation: Center of Nanomaterials for Renewable Energy (CNRE), State Key Lab of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi'an Jiaotong University, Xi'an, China 710049. hongkang.wang@mail.xjtu.edu.cn.
authors.forename: Daxian
authors.initials: D
authors.lastname: Cao
authors.affiliation: Center of Nanomaterials for Renewable Energy (CNRE), State Key Lab of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi'an Jiaotong University, Xi'an, China 710049. hongkang.wang@mail.xjtu.edu.cn.
authors.forename: Qizhen
authors.initials: Q
authors.lastname: Wu
authors.affiliation: Center of Nanomaterials for Renewable Energy (CNRE), State Key Lab of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi'an Jiaotong University, Xi'an, China 710049. hongkang.wang@mail.xjtu.edu.cn.
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Li
authors.affiliation: Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an, China 710049. g.yang@mail.xjtu.edu.cn.
authors.forename: Guang
authors.initials: G
authors.lastname: Yang
authors.affiliation: Center for Biomedical Engineering and Regenerative Medicine, Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China 710049. baoling@mail.xjtu.edu.cn.
authors.forename: Baolin
authors.initials: B
authors.lastname: Guo
authors.affiliation: Center of Nanomaterials for Renewable Energy (CNRE), State Key Lab of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi'an Jiaotong University, Xi'an, China 710049. hongkang.wang@mail.xjtu.edu.cn.
authors.forename: Chunming
authors.initials: C
authors.lastname: Niu