School of Physics and Materials Science, Engineering Research Center for Nanophotonics & Advanced Instrument, Shanghai Key Laboratory of Magnetic Resonance, East China Normal University , Shanghai 200062, China.
State Key Laboratory of Optoelectronic Materials and Technologies, Nanotechnology Research Center, School of Materials Science & Engineering, Sun Yat-sen University , Guangzhou 510275, Guangdong, China.
ACS Appl Mater Interfaces. 2017 Jan 25;9(3):2309-2316. doi: 10.1021/acsami.6b12529. Epub 2017 Jan 11.
Currently sodium-ion batteries (SIBs) as energy storage technology have attracted lots of interest due to their safe, cost-effective, and nonpoisonous advantages. However, many challenges remain for development of SIBs with high specific capacity, high rate capability, and long cycle life. Therefore, CuS as an important earth-abundant, low-cost semiconductor was applied as anode of SIBs with ether-based electrolyte instead of conventional ester-based electrolyte. By incorporating reduced graphene oxide (RGO) into CuS nanosheets and optimizing the cutoff voltage, it is found that the sodium-ion storage performance can be greatly enhanced using ether-based electrolyte. The CuS-RGO composites deliver an initial Coulombic efficiency of 94% and a maximum specific capacity of 392.9 mAh g after 50 cycles at a current density of 100 mA g. And a specific capacity of 345 mAh g is kept after 450 cycles at a current density of 1 A g. Such an excellent electrochemical performance is ascribed to the conductive network construction of CuS-RGO composites, the suppression of dissolved polysulfide intermediates by using ether-based electrolyte, and the avoidance of conversion-type reaction by optimizing the cutoff voltage.
目前，钠离子电池（SIBs）作为储能技术，由于其安全、经济高效和无毒的优势，引起了广泛关注。然而，要开发具有高比容量、高倍率性能和长循环寿命的 SIBs，仍然存在许多挑战。因此，CuS 作为一种重要的丰富、低成本半导体，被应用于基于醚的电解质而不是传统基于酯的电解质的 SIBs 作为阳极。通过将还原氧化石墨烯（RGO）掺入 CuS 纳米片中并优化截止电压，发现使用基于醚的电解质可以大大提高钠离子存储性能。CuS-RGO 复合材料在 100 mA g 的电流密度下循环 50 次后，初始库仑效率为 94%，最大比容量为 392.9 mAh g。在 1 A g 的电流密度下循环 450 次后，比容量保持在 345 mAh g。这种优异的电化学性能归因于 CuS-RGO 复合材料的导电网络构建、基于醚的电解质抑制溶解多硫化物中间体以及优化截止电压避免转换型反应。
