Wenelska Karolina, Kędzierski Tomasz, Bęben Damian, Mijowska Ewa
Department of Nanomaterials Physicochemistry, Szczecin Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology, Szczecin, Poland.
Nanores Sp. z o.o. Sp.k, Wroclaw, Poland.
Front Chem. 2023 Jan 16;10:1102207. doi: 10.3389/fchem.2022.1102207. eCollection 2022.
Since its discovery, graphene has been widely considered a great material that has advanced the Li-ion battery field and allowed development in its performance. However, most current graphene-related research is focused on graphene-based composites as electrode materials, highlighting the role of graphene in composite materials. Herein, we focused on a three-dimensional composite film with unique sandwich-type architecture based on ultrafast self-expanded and reduced graphene oxide (userGO) and exfoliated WS. This strategy allows non-active agents [e.g., carbon black and poly (vinylidene fluoride)] free electrodes in LIBs in the form of a film. The ultra-quick exothermal nature of the USER reaction allows the rapid release of internally generated gases to create highly porous channels inside the film. Hence, the improved Li-ion transport in the LIBs boosted the electrochemical performance of both film components (ex-WS and reduced graphene), resulting in a high specific capacity of 762 mAh/g at .05 A/g and high Coulombic efficiency (101%) after 1,000 cycles. Overall, userGO showed the highest capacity at a low current, and ex-WS provided a higher reversible capacity. These results showed that the expanded graphene layer is an excellent shield for ex-WS to protect against pulverization, promoting both stability and capacity.
自发现以来，石墨烯一直被广泛认为是一种推动锂离子电池领域发展并提升其性能的优质材料。然而，目前大多数与石墨烯相关的研究都集中在将基于石墨烯的复合材料用作电极材料，突出了石墨烯在复合材料中的作用。在此，我们专注于一种基于超快自膨胀还原氧化石墨烯（userGO）和剥离的WS₂的具有独特三明治型结构的三维复合薄膜。这种策略使得锂离子电池中无活性试剂（如炭黑和聚偏二氟乙烯）的电极能够以薄膜形式存在。USER反应的超快放热特性使得内部产生的气体能够快速释放，从而在薄膜内部形成高度多孔的通道。因此，锂离子电池中锂离子传输的改善提升了薄膜的两个组分（剥离的WS₂和还原石墨烯）的电化学性能，在0.05 A/g的电流下实现了762 mAh/g的高比容量以及1000次循环后99%的高库仑效率。总体而言，userGO在低电流下展现出最高的容量，而剥离的WS₂提供了更高的可逆容量。这些结果表明，膨胀的石墨烯层是剥离的WS₂防止粉化的优异屏障，同时提升了稳定性和容量。
