Zhu Yun Guang, Wang Ye, Han Zhao Jun, Shi Yumeng, Wong Jen It, Huang Zhi Xiang, Ostrikov Kostya Ken, Yang Hui Ying
Pillar of Engineering Product Development, Singapore University of Technology and Design, 20 Dover Drive, Singapore 138682.
Nanoscale. 2014 Dec 21;6(24):15020-8. doi: 10.1039/c4nr04736b. Epub 2014 Nov 4.
The catalytic role of germanium (Ge) was investigated to improve the electrochemical performance of tin dioxide grown on graphene (SnO(2)/G) nanocomposites as an anode material of lithium ion batteries (LIBs). Germanium dioxide (GeO(20) and SnO(2) nanoparticles (<10 nm) were uniformly anchored on the graphene sheets via a simple single-step hydrothermal method. The synthesized SnO(2)(GeO(2))0.13/G nanocomposites can deliver a capacity of 1200 mA h g(-1) at a current density of 100 mA g(-1), which is much higher than the traditional theoretical specific capacity of such nanocomposites (∼ 702 mA h g(-1)). More importantly, the SnO(2)(GeO(2))0.13/G nanocomposites exhibited an improved rate, large current capability (885 mA h g(-1) at a discharge current of 2000 mA g(-1)) and excellent long cycling stability (almost 100% retention after 600 cycles). The enhanced electrochemical performance was attributed to the catalytic effect of Ge, which enabled the reversible reaction of metals (Sn and Ge) to metals oxide (SnO(2) and GeO(2)) during the charge/discharge processes. Our demonstrated approach towards nanocomposite catalyst engineering opens new avenues for next-generation high-performance rechargeable Li-ion batteries anode materials.
研究了锗（Ge）的催化作用，以改善生长在石墨烯（SnO₂/G）纳米复合材料上的二氧化锡作为锂离子电池（LIBs）负极材料的电化学性能。通过简单的一步水热法，将二氧化锗（GeO₂）和二氧化锡纳米颗粒（<10 nm）均匀地锚定在石墨烯片上。合成的SnO₂(GeO₂)₀.₁₃/G纳米复合材料在100 mA g⁻¹的电流密度下可提供1200 mA h g⁻¹的容量，这远高于此类纳米复合材料的传统理论比容量（约702 mA h g⁻¹）。更重要的是，SnO₂(GeO₂)₀.₁₃/G纳米复合材料表现出更好的倍率性能、大电流能力（在2000 mA g⁻¹的放电电流下为885 mA h g⁻¹）和优异的长循环稳定性（600次循环后几乎保持100%）。电化学性能的增强归因于Ge的催化作用，它使得金属（Sn和Ge）在充放电过程中可逆地反应生成金属氧化物（SnO₂和GeO₂）。我们展示的纳米复合催化剂工程方法为下一代高性能可充电锂离子电池负极材料开辟了新途径。
