Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
University of Chinese Academy of Sciences, Beijing 101400, China.
Molecules. 2023 Mar 13;28(6):2608. doi: 10.3390/molecules28062608.
Potassium-ion batteries (PIBs) have aroused a large amount of interest recently due to the plentiful potassium resource, which may show cost benefits over lithium-ion batteries (LIBs). However, the huge volume expansion induced by the intercalation of large-sized potassium ions and the intrinsic sluggish kinetics of the anode hamper the application of PIBs. Herein, by rational design, nano-roses assembled from petals with a MoS/monolayer carbon (C-MoS) sandwiched structure were successfully synthesized. The interlayer distance of ultrathin C-MoS was expanded from original MoS of 6.2 to 9.6 Å due to the formation of the MoS-carbon inter overlapped superstructure. This unique structure efficiently alleviates the mechanical strain, prevents the aggregation of MoS, creates more active sites, facilitates electron transport, and enhances the specific capacity and K diffusion kinetics. As a result, the prepared C-MoS-1 anode delivers a high reversible specific capacity (437 mAh g at 0.1 A g) and satisfying rate performance (123 mAh g at 6.4 A g). Therefore, this work provides new insights into the design of high-performance anode materials of PIBs.
钾离子电池（PIBs）由于钾资源丰富，可能比锂离子电池（LIBs）具有成本优势，因此最近引起了广泛关注。然而，由于大尺寸钾离子的嵌入引起的巨大体积膨胀和阳极内在的缓慢动力学限制了 PIBs 的应用。在此，通过合理设计，成功合成了由花瓣组装而成的纳米蔷薇，其中夹有 MoS/单层碳（C-MoS）结构。由于 MoS-碳交叠超结构的形成，超薄 C-MoS 的层间距从原始 MoS 的 6.2 Å扩展到 9.6 Å。这种独特的结构有效地缓解了机械应变，防止了 MoS 的聚集，创造了更多的活性位点，促进了电子传输，并提高了比容量和 K 扩散动力学。因此，所制备的 C-MoS-1 阳极具有高可逆比容量（在 0.1 A g 时为 437 mAh g）和令人满意的倍率性能（在 6.4 A g 时为 123 mAh g）。因此，这项工作为设计高性能 PIBs 阳极材料提供了新的思路。
