Raju Vadivukarasi, Wang Xingfeng, Luo Wei, Ji Xiulei
Department of Chemistry, Oregon State University, Corvallis, Oregon (USA).
Chemistry. 2014 Jun 16;20(25):7686-91. doi: 10.1002/chem.201402280. Epub 2014 May 7.
A novel ambient hydrolysis deposition (AHD) methodology that employs sequential water adsorption followed by a hydrolysis reaction to infiltrate SnO2 nanoparticles into the nanopores of mesoporous carbon in a conformal and controllable manner is introduced. The empty space in the SnO2/C composites can be adjusted by varying the number of AHD cycles. An SnO2/C composite with an intermediate SnO2 loading exhibited an initial specific delithiation capacity of 1054 mAh g(-1) as an anode for Li-ion batteries. The capacity contribution from SnO2 in the composite electrode approaches the theoretical capacity of SnO2 (1494 mAh g(-1)) if both Sn alloying and SnO2 conversion reactions are considered to be reversible. The composite shows a specific capacity of 573 mAh g(-1) after 300 cycles, that is, one of the most stable cycling performances for SnO2/mesoporous carbon composites. The results demonstrated the importance of well-tuned empty space in nanostructured composites to accommodate expansion of the electrode active mass during alloying/dealloying and conversion reactions.
介绍了一种新型的环境水解沉积(AHD)方法,该方法采用顺序水吸附,然后进行水解反应,以共形且可控的方式将SnO₂纳米颗粒渗透到介孔碳的纳米孔中。通过改变AHD循环次数,可以调节SnO₂/C复合材料中的空隙。一种具有中等SnO₂负载量的SnO₂/C复合材料作为锂离子电池的阳极,其初始比脱锂容量为1054 mAh g⁻¹。如果同时考虑Sn合金化和SnO₂转化反应都是可逆的,那么复合电极中SnO₂的容量贡献接近SnO₂的理论容量(1494 mAh g⁻¹)。该复合材料在300次循环后显示出573 mAh g⁻¹的比容量,即SnO₂/介孔碳复合材料中最稳定的循环性能之一。结果表明,在纳米结构复合材料中,调整良好的空隙对于在合金化/脱合金化和转化反应过程中容纳电极活性物质的膨胀非常重要。