Microwave-assisted synthesis of SnO2/mesoporous carbon core-satellite microspheres as anode material for high-rate lithium ion batteries

The highly ordered microspheres containing ultrafine SnO2 nanoparticles and mesoporous carbon is fabricated using microwave-assisted hydrothermal method for high-rate and durable Li-ion battery application. The uniformly carbon nanosphere with an average diameter of around 90 nm exhibits large specific surface area and good mechanical stability to minimize the volume expansion of SnO2 during intercalation-deintercalation. The homogeneous coverage with 3-6 nm SnO2 nanoparticle provides sufficient active sites to facilitate the rapid lithiation-delithiation process through the fast ion transfer rates. Remarkably, SnO2/OMCS at Sn/C ratio of 35% exhibits an excellent initial capacity of 1770 mAh g(-1) at a current density of 35 mAg(-1) and can maintain at a stable capacity of 400 mAh g(-1) under an ultrahigh current density of 3500 mA g(-1) after 400 cycles. The intimate contact of SnO2 with ordered mesoporous carbon sphere shortens the electrons transport paths, resulting in the enhancement of stable lithium storage capacity at a high current density. Results obtained in this study clearly demonstrate that SnO2/OMCS nanocomposite is a promising material for lithium-ion battery and can provide an alternative to fabricate novel mesoporous carbon sphere-based nanocomposites for long cycle life and high-rate energy storage application. (C) 2018 Elsevier B.V. All rights reserved.