Foldable mobile phones are gaining popularity these days. As the popularity of such intelligent flexible devices and electric vehicles increases, the demand for high-energy, long-life and fast-charging energy storage systems is increasing.
The current lithium-ion battery technologies cannot meet this demand, so the focus is progressively shifting toward next-generation batteries. Recently, a research team at POSTECH succeeded in synthesizing a lithium-sulfur battery cathode material in just 30 minutes by using sulfur, which is discarded as a by-product of oil refinery processing.
由Moon Jeong Park教授和博士学位领导的研究团队。Postech化学系的候选人Haneol Kang开发了一种创新的锂硫（LI-S）电池，可提供高能量密度，快速充电和机械灵活性。这是富含硫的层次分层共聚物的首次合成，即无需使用表面活性剂或空间稳定剂的快速反应时间少于30分钟。该研究的发现在在线版本中作为突发新闻发表Nano Energyon August 25, 2021
与目前使用的剧毒过渡金属阴极材料不同，由于其低成本，天然丰度和低毒性，Sulfur引起了人们的注意。欧洲杯足球竞彩特别是，LI-S电池具有较高的理论能量密度（2,600WH kg-1) and high capacity (1672mAh g-1），显示其潜力作为下一代电池。然而，硫从根本上具有较低的电导率，从而阻碍了活性材料的完全利用，从而减慢了电荷/放电周期。欧洲杯足球竞彩它还具有高溶解度在电解质中的缺点，从而降低了电池的寿命。
To overcome these limitations, the research team did not use the melt-diffusion process – unlike the conventional sulfur electrode – but conducted copolymerization using the inverse vulcanization of sulfur and vinylphosphonic acid (VPA) to synthesize sulfur-based polymer particles in just 30 minutes. The resultant sulfur particles are composed of phase-separated α-sulfur and sulfur-VPA network (SVPA) based on low-density sulfur allotropes.
在短时间内形成均匀尺寸的分层颗粒的关键是硫自由基和VPA之间的自催化反应。欧洲杯猜球平台在反应的开头形成了与VPA相连的长硫链，以稳定无表面活性剂的SVPA的球形形状。有趣的是，已经证明在SVPA颗粒的表面自发形成皱纹和毛孔，这促进了电解质渗透到阴极中，同时又缓解了施加到电极表面的机械应力。欧洲杯猜球平台
通过此，研究人员证实，可以基于简单的合成方法将多孔结构引入活性材料本身中，以促进电解质的穿透，并通过将硫同素嵌入SVPA框架中提高电极的机械完整性来提高电极的机械完整性量较低。此外，研究人员有效地防止了通过磷酸官能团在活性材料表面大量存在的磷酸官能团洗脱，从而实现了出色的锂硫电池特性。活性材料本身具有出色的弹性，并且具有交联聚合物的优势，表明其作为柔性电极的潜力。
“在这项研究中，通过以低成本且环保的方式合成与丰富的磷酸基团的反硫化聚合物来开发柔性锂硫电池。”explained Professor Moon Jeong Park who led the study. "The findings are significant in that it has chemically trapped lithium polysulfides, resolving the elution issue that has hampered commercialization, and has increased the potential use in wearable device batteries by adding flexible characteristics to the sulfur cathode, which has been difficult to implement so far."
This research was conducted with the support from the Mid-Career Researcher Program of the National Research Foundation of Korea, the Creative Materials Discovery Program, and the Science Research Center Program.
来源：https://www.postech.ac.kr/eng/