Effect Effect of pore distribution on the lithium storage properties of porous C/SnO2 nanofibers

摘要

Carbon-coated SnO2 composite nanofibers has been considered as an efficient way to alleviate the enormous volume change problem of tin-based anodes for lithium ion batteries (LIBs). Herein, porous carbon/SnO2 nanofibers were prepared via single-needle electrospinning which was followed by carbonization treatment. The procedure involved two categories of precursors of SnO2, stannic chloride pentahydrate and stannic acetate, whereas former was fully dissolved while later was partially dissolved in solvent, leading to different pore distribution in cooperating with thermal decomposition of poly methyl methacrylate. The pores generated from stannic chloride pentahydrate/polymethyl methacrylate system were randomly distributed on the surface of nanofibers. In the case of stannic acetate/polymethyl methacrylate derived composites, the thermolysis of polymer left multichannels within the nanofibers coupled with SnO2 nanoparticles. Galvanostatic charge/discharge was carried out to evaluate them as anode materials for LIBs. It was found that multichannel carbon/SnO2 nanofibers with large specific surface area (34.97 m(2)/g) achieved better rate capability and stable capacity retention of 89.9% after 50 cycles. The longitudinally aligned pores facilitated lithium diffusion and transference, which avoided nonuniform deposition and separation of lithium ions, thereby further enhancing the stability during the discharge/charge process. (C) 2017 Elsevier B.V. All rights reserved.