Wang Yun-Xiao, Chou Shu-Lei, Wexler David, Liu Hua-Kun, Dou Shi-Xue
Institute for Superconducting & Electronic Materials (ISEM), Innovation Campus, University of Wollongong, Wollongong, NSW, 2519 (Australia).
Chemistry. 2014 Jul 28;20(31):9607-12. doi: 10.1002/chem.201402563. Epub 2014 Jul 2.
Sodium-ion energy storage, including sodium-ion batteries (NIBs) and electrochemical capacitive storage (NICs), is considered as a promising alternative to lithium-ion energy storage. It is an intriguing prospect, especially for large-scale applications, owing to its low cost and abundance. MoS2 sodiation/desodiation with Na ions is based on the conversion reaction, which is not only able to deliver higher capacity than the intercalation reaction, but can also be applied in capacitive storage owing to its typically sloping charge/discharge curves. Here, NIBs and NICs based on a graphene composite (MoS2 /G) were constructed. The enlarged d-spacing, a contribution of the graphene matrix, and the unique properties of the MoS2 /G substantially optimize Na storage behavior, by accommodating large volume changes and facilitating fast ion diffusion. MoS2 /G exhibits a stable capacity of approximately 350 mAh g(-1) over 200 cycles at 0.25 C in half cells, and delivers a capacitance of 50 F g(-1) over 2000 cycles at 1.5 C in pseudocapacitors with a wide voltage window of 0.1-2.5 V.
钠离子储能，包括钠离子电池（NIBs）和电化学电容储能（NICs），被认为是锂离子储能的一种有前景的替代方案。由于其低成本和丰富性，这是一个引人入胜的前景，特别是对于大规模应用。MoS2与Na离子的脱嵌/嵌入基于转化反应，该反应不仅能够提供比嵌入反应更高的容量，而且由于其典型的倾斜充放电曲线，还可应用于电容储能。在此，构建了基于石墨烯复合材料（MoS2/G）的NIBs和NICs。石墨烯基体导致的d间距增大以及MoS2/G的独特性能，通过适应大的体积变化和促进快速离子扩散，极大地优化了钠存储行为。在半电池中，MoS2/G在0.25 C下200次循环中表现出约350 mAh g(-1)的稳定容量，在具有0.1 - 2.5 V宽电压窗口的赝电容器中，在1.5 C下2000次循环中提供50 F g(-1)的电容。
