PDF(Pubmed)
Abstract：
Sulfurized polyacrylonitrile (SPAN) is a promising cathode material for lithium-sulfur batteries owing to its reversible solid-solid conversion for high-energy-density batteries. However, the sluggish reaction kinetics of SPAN cathodes significantly limit their output capacity, especially at high cycling rates. Herein, a CNT-interpenetrating hierarchically porous SPAN electrode is developed by a simple phase-separation method. Flexible self-supporting SPAN cathodes with fast electron/ion pathways are synthesized without additional binders, and exceptional high-rate cycling performances are obtained even with substantial sulfur loading. For batteries assembled with this special cathode, an impressive initial discharge capacity of 1090 mAh g-1 and a retained capacity of 800 mAh g-1 are obtained after 1000 cycles at 1 C with a sulfur loading of 1.5 mg cm-2. Furthermore, by incorporating V2O5 anchored carbon fiber as an interlayer with adsorption and catalysis function, a high initial capacity of 614.8 mAh g-1 and a notable sustained capacity of 500 mAh g-1 after 500 cycles at 5 C are achieved, with an ultralow decay rate of 0.037% per cycle with a sulfur loading of 1.5 mg cm-2. The feasible construction of flexible SPAN electrodes with enhanced cycling performance enlists the current processing as a promising strategy for novel high-rate lithium-sulfur batteries and other emerging battery electrodes.
摘要：
硫化聚丙烯腈（SPAN）是锂硫电池的正极材料，由于其可逆的固体-固体转化为高能量密度电池。然而,SPAN阴极的缓慢反应动力学显著限制了它们的输出容量，尤其是在高循环速率下。在这里，通过简单的相分离方法开发了CNT互穿分层多孔SPAN电极。具有快速电子/离子通道的柔性自支撑SPAN阴极无需额外的粘合剂即可合成，和优异的高速率循环性能，即使有大量的硫负荷获得。对于用这种特殊阴极组装的电池，在1C下1000次循环后，硫负载为1.5mgcm-2，获得了令人印象深刻的1090mAhg-1初始放电容量和800mAhg-1保留容量。此外，通过引入V2O5锚定碳纤维作为具有吸附和催化功能的中间层，614.8mAhg-1的高初始容量和在5C下500次循环后500mAhg-1的显著持续容量，每个循环的衰变速率为0.037％，硫负载为1.5mgcm-2。具有增强的循环性能的柔性SPAN电极的可行构造使当前处理成为新型高倍率锂-硫电池和其他新兴电池电极的有希望的策略。
