Electrochimica Acta, Vol.224, 608-621, 2017
A comparative study on the performance of binary SnO2/NiO/C and Sn/C composite nanofibers as alternative anode materials for lithium ion batteries
The development of alternative anode materials out of flexible composite nanofibers has seen a growing interest. In this paper, binary carbon nanofiber electrodes of SnO2/NiO and Sn nanoparticles are produced using a scalable technique, Forcespinning (FS), and subsequent thermal treatment (carbonization). The Sn/C composite nanofibers were porous and flexible, while the SnO2/NiO composite nanofibers had "hairy-like" particles and pores on the fiber strands. The nanofiber preparation process involved the FS of Sn/PAN and SnO2/NiO/PAN solution precursors into nanofibers and subsequent stabilization in air at 280 degrees C and calcination at 800 degrees C under an inert atmosphere. The flexible composite nanofibers were directly used as working electrodes in lithium-ion batteries without a current collector, conducting additives, or binder. The electrochemical performance of the SnO2/NiO/C and Sn/C composite fiber anodes showed a comparable cycle performance of about 675 mAhg(-1) after 100 cycles. However, the SnO2/NiO/C electrode exhibited a better rate performance than the Sn/C composite anode and was able to recover its capacity after charging with a higher current density. A postmortem analysis of the composite nanofiber electrode after the aging process revealed a heavily passivated electrode from the electrolyte decomposition by-prbducts. The synthesis and processing methods used to produce these composite nanofibers clearly were a factor for the high rate capability and excellent cycle performance of these binary composite electrodes, largely on the account of the unique structure and properties of the composite nanofibers. (C) 2016 Published by Elsevier Ltd.