3D SnO2/Graphene Hydrogel Anode Material for Lithium-Ion Battery
Xue-Jun BAI, 1 上海航天电源技术有限责任公司,上海201615,1 Shanghai Aerospace Power Technology LTD, Shanghai 201615, P. R. China, Min HOU, Chan LIU, Biao WANG, Hui CAO, Dong WANG, 2 东华大学材料科学与工程学院,上海201620,2 College of Material Science and Engineering, Donghua University, Shanghai 201620, P. R. China, 3 上海空间电源研究所,上海200245,3 Shanghai Institute of Space Power Source, Shanghai 200245, P. R. China
2017
Wuli huaxue xuebao
摘要:通过溶液水解反应在氧化石墨烯表面引入氧化锡(SnO2)纳米颗粒,再经过自组装作用形成具有三维结 构的氧化锡/石墨烯水凝胶(SnO2-GH)负极材料。其中三维多孔的石墨烯水凝胶为碳质缓冲基体,SnO2纳米 颗粒为活性物质,其颗粒尺寸为 2-3 nm,均匀分布在石墨烯层上,担载量可以达到 54% (w,质量分数)。 直接将该材料用作锂离子电池负极时,在 5000 mA•g -1 的大电流密度下循环 60 次容量稳定在 500 mAh•g -1 , Abstract: With the widespread use of mobile electronic devices and increasing demand for electric energy storage in the transportation and energy sectors, lithium-ion batteries (LIBs) have become a major research and development focus in recent years. The current
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... n of LIBs use graphite as the anode material, which has a theoretical capacity of 372 mAh•g -1 . Tin-based materials are considered promising anode materials for next-generation LIBs because of their favorable working voltage and unsurpassed theoretical specific capacity. However, overcoming the rapid storage capacity degradation of tin caused by its large volumetric changes (> 200%) during cycling remains a major challenge to the successful implementation of such materials. In this paper, SnO2 nanoparticles with a diameter of 2-3 nm were used as active materials in LIB anodes and a threedimensional (3D) graphene hydrogel (GH) was used as a buffer to decrease the volumetric change. Typically, SnCl4 aqueous solution (18 mL, 6.4 mmol•L -1 ) and graphene oxide (GO) suspension (0.5% (w, mass fraction), 2 mL) were mixed together via sonication. NaOH aqueous solution (11.4 mmol•L -1 , 40 mL) was slowly added and then the mixture was stirred for 2 h to obtain a stable suspension. Vitamin C (VC, 80 mg) was then added as a reductant. The mixture was kept at 80°C for 24 h to reduce and self-assemble. The resulting black block was washed repeatedly with distilled deionized water and freeze-dried to obtain SnO2-GH. In this composite, GH provides large specific surface area for efficient loading (54% (w)) and uniform distribution of nanoparticles. SnO2-GH delivered a capacity of 500 mAh•g -1 at 5000 mA•g -1 and 865 mAh•g -1 at 50 mA•g -1 after rate cycling.
doi:10.3866/pku.whxb201610272
fatcat:inai542zorb7na7pezrw6mnstu
