Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University , Shanghai 200092, China.
Additive Manufacturing Institute, College of Mechatronics and Control Engineering, Shenzhen University , Shenzhen 518060, China.
ACS Appl Mater Interfaces. 2018 Jan 31;10(4):3938-3947. doi: 10.1021/acsami.7b16174. Epub 2018 Jan 16.
Carbon hosts have been utilized to obtain composite cathodes with high sulfur loadings for Li-S batteries. However, the complicated synthesis process may hinder their practical applications. Their mechanical and electrochemical properties shall be further improved. Herein, a facile scalable dip-coating process is developed to synthesize a flexible composite cathode with a high sulfur loading. Via the process, a hybrid composed of carbon nanotubes, carbon black, sulfur, and titania nanoparticles is successfully conformally coated on the carbonized textile (c-textile). The formed flexible c-textile@S/TiO cathodes with sulfur loadings of 1.5 and 3.0 mg cm can deliver reversible discharge capacities of 860 and 659 mA h g at 2 C, respectively. For the latter one, it can retain 94% of the initial capacity after 400 cycles with a high Coulombic efficiency (∼96%). When its sulfur loading is further increased to 7.0 mg cm, its areal capacity reaches 5.2 mA h cm. Such excellent performance is ascribed to the synergy effect of the three-dimension conductive hierarchical pore structure and TiO additive. They can physically and chemically entrap the soluble polysulfides in the composite cathode. The as-synthesized free-standing composite electrode is of low cost and a high areal capacity, making it suitable for flexible energy storage applications based on Li-S batteries.
碳载体已被用于获得具有高硫负载的 Li-S 电池复合阴极。然而，复杂的合成工艺可能会阻碍其实际应用。它们的机械和电化学性能需要进一步提高。在此，开发了一种简便的可扩展浸涂工艺，用于合成具有高硫负载的柔性复合阴极。通过该工艺，成功地将由碳纳米管、炭黑、硫和纳米二氧化钛组成的混合物在碳化纺织品（c-textile）上进行了共形涂覆。形成的柔性 c-textile@S/TiO 阴极的硫负载量分别为 1.5 和 3.0 mg cm 时，在 2 C 下的可逆放电容量分别为 860 和 659 mA h g。对于后者，在 400 次循环后，它可以保持 94%的初始容量，且库仑效率（约 96%）较高。当硫负载量进一步增加到 7.0 mg cm 时，其面积容量达到 5.2 mA h cm。如此优异的性能归因于三维导电分层孔结构和 TiO 添加物的协同效应。它们可以物理和化学地捕获复合阴极中的可溶性多硫化物。所合成的自支撑复合电极成本低、面积容量高，适用于基于 Li-S 电池的柔性储能应用。
