Small-Molecule Polycyclic Aromatic Hydrocarbons
In article number 2400273, Jeng-Kuei Chang, Elise Yu-Tzu Li, Yu-Sheng Su, and co-workers present geometric variations of pyrene crystals during the electrochemical process in Li-ion batteries. The image illustrates the irreversible structural collapse caused by the vertical expansion of pyrene dimers, leading to the dissolution of pyrene into the electrolyte, a key factor affecting the long-term cycling stability of the anode material.
Lithium-sulfur batteries (LSBs) present a promising alternative to conventional lithium-ion (Li-ion) batteries due to their high energy density and theoretical capacity. However, their practical application is hindered by issues such as poor sulfur utilization, highly soluble lithium polysulfides (LiPSs), and rapid capacity decay. This study introduces an innovative cell configuration using a separator coated with reduced graphene oxide/carbon nanotube (rGO/CNT) microspheres. The rGO/CNT-coated separator aims to enhance electron transfer, confine LiPSs within the cathode region, and mitigate their migration to the anode. In particular, the LSB cell with an rGO/CNT-modified separator delivers an impressive initial capacity of 1482 mAh g−1 and demonstrates a low capacity decay rate of 0.09% per cycle. The highly conductive rGO/CNT-coated separator enhances active material utilization even at high rates, resulting in a significant capacity of 824 mAh g−1 at 4C. Furthermore, the rGO/CNT-modified separator shows an impressive capacity of 895 mAh g−1 under high sulfur loading of 4.8 mg cm−2 with long-term cycling performance. The results demonstrate that the rGO/CNT-coated separator significantly enhances sulfur reutilization, reduces capacity decay, and improves the electrochemical stability of LSBs. This configuration simplifies the manufacturing process and offers a viable solution for the practical application of LSBs.
Our lab hosted a well-deserved gathering to celebrate the end of mid-terms! After weeks of studying and hard work, we took some time to unwind, share project updates, and enjoy good food together. The event was filled with laughter, team games, and inspiring conversations that reminded us of the supportive spirit we share. It was a great way to recharge and reconnect as we look forward to the next phase of the semester with renewed energy and motivation!
