Xia Jiaojiao, Xu Peng, Wang Wei, Hu Pingping, Sun Yan, Shao Jiaojing
College of Materials and Metallurgy, Guizhou University, Guiyang 550025, China.
Teaching and Scientific Research Center, Guizhou Qiannan Economic College, Qiannan 550600, China.
Langmuir. 2024 Jul 16. doi: 10.1021/acs.langmuir.4c01451.
Challenges including rapid capacity degradation and reduced Coulombic efficiency due to the shuttle effect have hindered the commercial viability of lithium-sulfur (Li-S) batteries. A novel sandwich-structured electrode with an optimized electrode structure and current collector interface design was presented as a free-standing positive electrode for Li-S batteries. Fabricated via a simple slurry coating process, the electrode embedded multiwalled carbon nanotubes within carbon nanofiber composite films (PCNF/T). Owing to the superior conductivity and reduced weight in comparison to both carbon nanofibers (PCNF) and the conventional aluminum foil current collector (Al), the PCNF/T electrode exhibited diminished polarization and accelerated redox reaction kinetics. Thus, it delivers an initial discharge capacity of 990.23 mA h g at 0.5 C. Even after 400 cycles, while retains a reversible capacity of 707.45 mA h g, corresponding to a minimal capacity degradation rate of merely 0.07% per cycle. Notably, the electrode exhibits a capacity retention of 619.81 mA h g after 400 cycles at 1 C, with a capacity decay rate of only 0.08% per cycle. This study presents an innovative approach to developing a new free-standing cathode for high-performance Li-S batteries.
包括由于穿梭效应导致的快速容量衰减和库仑效率降低在内的挑战阻碍了锂硫（Li-S）电池的商业可行性。提出了一种具有优化电极结构和集流体界面设计的新型三明治结构电极，作为Li-S电池的独立正极。该电极通过简单的浆料涂覆工艺制备，在碳纳米纤维复合膜（PCNF/T）中嵌入了多壁碳纳米管。与碳纳米纤维（PCNF）和传统铝箔集流体（Al）相比，由于具有优异的导电性和减轻的重量，PCNF/T电极表现出极化减小和氧化还原反应动力学加速。因此，它在0.5 C下的初始放电容量为990.23 mA h g。即使在400次循环后，仍保持707.45 mA h g的可逆容量，对应于仅0.07%/循环的最小容量衰减率。值得注意的是，该电极在1 C下400次循环后容量保持率为619.81 mA h g，容量衰减率仅为0.08%/循环。本研究提出了一种开发高性能Li-S电池新型独立阴极的创新方法。
