Porous Hybrid Nanofibers Comprising ZnSe/CoSe?/Carbon with Uniformly Distributed Pores as Anodes for High-Performance Sodium-Ion Batteries.

ABSTRACT: Well-designed porous structured bimetallic ZnSe/CoSe?/carbon composite nanofibers with uniformly distributed pores were prepared as anodes for sodium-ion batteries by electrospinning and subsequent simple heat-treatment processes. Size-controlled polystyrene (PS) nanobeads in the electrospinning solution played a key role in the formation and uniform distribution of pores in the nanofiber structure, after the removal of selected PS nanobeads during the heat-treatment process. The porous ZnSe/CoSe?/C composite nanofibers were able to release severe mechanical stress/strain during discharge-charge cycles, introduce larger contact area between the active materials and the electrolyte, and provide more active sites during cycling. The discharge capacity of porous ZnSe/CoSe2/C composite nanofibers at the 10,000th cycle was 297 mA h g-1, and the capacity retention measured from the second cycle was 81%. The final rate capacities of porous ZnSe/CoSe2/C composite nanofibers were 438, 377, 367, 348, 335, 323, and 303 mA h g-1 at current densities of 0.1, 0.5, 1, 3, 5, 7, and 10 A g-1, respectively. At the higher current densities of 10, 20, and 30 A g-1, the final rate capacities were 310, 222, and 141 mA h g-1, respectively.

SUBMITTER: Jeong SY 

PROVIDER: S-EPMC6835312 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature