Yoo Hyundong, Park Eunjun, Bae Juhye, Lee Jaewoo, Chung Dong Jae, Jo Yong Nam, Park Min-Sik, Kim Jung Ho, Dou Shi Xue, Kim Young-Jun, Kim Hansu
Department of Energy Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 133-791, Republic of Korea.
Institute for Superconducting and Electronic Materials (ISEM), Australian Institute for Innovative Materials (AIIM), University of Wollongong, North Wollongong, New South Wales, 2500, Australia.
Sci Rep. 2018 May 2;8(1):6904. doi: 10.1038/s41598-018-25159-4.
Silicon (Si) based materials are highly desirable to replace currently used graphite anode for lithium ion batteries. Nevertheless, its usage is still a big challenge due to poor battery performance and scale-up issue. In addition, two-dimensional (2D) architectures, which remain unresolved so far, would give them more interesting and unexpected properties. Herein, we report a facile, cost-effective, and scalable approach to synthesize Si nanocrystals embedded 2D SiO nanofoils for next-generation lithium ion batteries through a solution-evaporation-induced interfacial sol-gel reaction of hydrogen silsesquioxane (HSiO, HSQ). The unique nature of the thus-prepared centimeter scale 2D nanofoil with a large surface area enables ultrafast Li insertion and extraction, with a reversible capacity of more than 650 mAh g, even at a high current density of 50 C (50 A g). Moreover, the 2D nanostructured Si/SiO nanofoils show excellent cycling performance up to 200 cycles and maintain their initial dimensional stability. This superior performance stems from the peculiar nanoarchitecture of 2D Si/SiO nanofoils, which provides short diffusion paths for lithium ions and abundant free space to effectively accommodate the huge volume changes of Si during cycling.
硅基材料非常适合用于替代目前锂离子电池中使用的石墨负极。然而，由于电池性能不佳和放大问题，其应用仍然是一个巨大的挑战。此外，二维（2D）结构目前仍未得到解决，这将赋予它们更有趣和意想不到的特性。在此，我们报告了一种简便、经济高效且可扩展的方法，通过氢倍半硅氧烷（HSiO，HSQ）的溶液蒸发诱导界面溶胶 - 凝胶反应，合成用于下一代锂离子电池的嵌入二维SiO纳米箔的硅纳米晶体。由此制备的具有大表面积的厘米级二维纳米箔的独特性质能够实现超快的锂嵌入和脱出，即使在50 C（50 A g）的高电流密度下，可逆容量也超过650 mAh g。此外，二维纳米结构的Si/SiO纳米箔在高达200次循环时表现出优异的循环性能，并保持其初始尺寸稳定性。这种优异的性能源于二维Si/SiO纳米箔独特的纳米结构，它为锂离子提供了短扩散路径和丰富的自由空间，以有效适应循环过程中硅的巨大体积变化。
