Senthil Chenrayan, Kim Sun-Sik, Jung Hyun Young
Department of Energy Engineering, Gyeongsang National University, Jinju-si, Gyeongnam, 52725, South Korea.
Future Convergence Technology Research Institute, Gyeongsang National University, Jinju-si, Gyeongnam, 52725, South Korea.
Nat Commun. 2022 Jan 10;13(1):145. doi: 10.1038/s41467-021-27777-5.
Polymer binders for sulfur cathodes play a very critical role as they prerequisites for an in-situ immobilization against polysulfide shuttle and volume change, while ensuring good adhesion within active materials for ion conduction along with robust mechanical and chemical stability. Here, we demonstrate anionic surface charge facilitated bio-polymer binder for sulfur cathodes enabling excellent performance and fire safety improvement. The aqueous-processable tragacanth gum-based binder is adjusted to house high sulfur loading over 12 mg cm without compromising the sulfur utility and reversibility, imparting high accessibility for Li-ions to sulfur particles about 80%. The intrinsic rod and sphere-like saccharidic conformal fraction's multifunctional polar units act as active channels to reach the sulfur particles. As a result, the binder entraps polysulfides with 46% improvement and restrains the volume changes within 16 % even at 4 C. Moreover, the flexible Li-S battery delivers a stack gravimetric energy density of 243 Wh kg, demonstrating high reactivity of sulfur along with good shape conformality, which would open an avenue for the potential development of the compact and flexible high-power device.
用于硫阴极的聚合物粘结剂起着非常关键的作用，因为它们是原位固定以防止多硫化物穿梭和体积变化的先决条件，同时确保活性材料内部具有良好的附着力以实现离子传导，并具有强大的机械和化学稳定性。在此，我们展示了一种用于硫阴极的阴离子表面电荷促进型生物聚合物粘结剂，其具有优异的性能并提高了消防安全性能。这种可水加工的基于黄芪胶的粘结剂经过调整，能够容纳超过12 mg cm的高硫负载量，而不会损害硫的利用率和可逆性，使锂离子对硫颗粒的可及性高达约80%。固有的棒状和球状糖类共形部分的多功能极性单元充当到达硫颗粒的活性通道。结果，该粘结剂捕获多硫化物的能力提高了46%，即使在4C时也能将体积变化限制在16%以内。此外，柔性锂硫电池的堆叠重量能量密度为243 Wh kg，展示了硫的高反应活性以及良好的形状适形性，这将为紧凑型和柔性高功率器件的潜在发展开辟一条道路。
