Cao Jun-Ming, Ma Ming-Yang, Liu Han-Hao, Yang Jia-Lin, Liu Yue, Zhang Kai-Yang, Butt Faaz A, Gu Zhen-Yi, Li Kai, Wu Xing-Long
MOE Key Laboratory for UV Light-Emitting Materials and Technology, Northeast Normal University, Changchun, Jilin, 130024, P. R. China.
Department of Chemistry, Northeast Normal University, Changchun, Jilin, 130024, P. R. China.
Small. 2024 Mar;20(11):e2311024. doi: 10.1002/smll.202311024. Epub 2024 Jan 18.
Sodium-ion batteries (SIBs) have gradually become one of the most promising energy storage techniques in the current era of post-lithium-ion batteries. For anodes, transitional metal selenides (TMSe) based materials are welcomed choices , owing to relatively higher specific capacities and enriched redox active sites. Nevertheless, current bottlenecks are blamed for their poor intrinsic electronic conductivities, and uncontrollable volume expansion during redox reactions. Given that, an interfacial-confined isochronous conversion strategy is proposed, to prepare orthorhombic/cubic biphasic TMSe heterostructure, namely CuSe/Cu VSe , through using MXene as the precursor, followed by Cu/Se dual anchorage. As-designed biphasic TMSe heterostructure endows unique hierarchical structure, which contains adequate insertion sites and diffusion spacing for Na ions, besides, the surficial pseudocapacitive storage behaviors can be also proceeded like 2D MXene. By further investigation on electronic structure, the theoretical calculations indicate that biphasic CuSe/Cu VSe anode exhibits well-enhanced properties, with smaller bandgap and thus greatly improves intrinsic poor conductivities. In addition, the dual redox centers can enhance the electrochemical Na ions storage abilities. As a result, the as-designed biphasic TMSe anode can deliver a reversible specific capacity of 576.8 mAh g at 0.1 A g , favorable Na affinity, and reduced diffusion barriers. This work discloses a synchronous solution toward demerits in conductivities and lifespan, which is inspiring for TMSe-based anode development in SIBs systems.
在当前锂离子电池时代之后，钠离子电池（SIBs）已逐渐成为最具前景的储能技术之一。对于阳极而言，基于过渡金属硒化物（TMSe）的材料是受欢迎的选择，这是由于其具有相对较高的比容量和丰富的氧化还原活性位点。然而，目前的瓶颈在于其固有的电子电导率较差，以及在氧化还原反应过程中体积不可控地膨胀。鉴于此，提出了一种界面受限的同步转化策略，以通过使用MXene作为前驱体，随后进行铜/硒双锚固，来制备正交/立方双相TMSe异质结构，即CuSe/CuVSe。所设计的双相TMSe异质结构赋予了独特的分级结构，该结构除了为钠离子提供足够的插入位点和扩散间距外，还可以像二维MXene一样进行表面赝电容存储行为。通过对电子结构的进一步研究，理论计算表明双相CuSe/CuVSe阳极表现出显著增强的性能，具有更小的带隙，从而极大地改善了固有的低电导率。此外，双氧化还原中心可以增强电化学钠离子存储能力。结果，所设计的双相TMSe阳极在0.1 A g时可提供576.8 mAh g的可逆比容量、良好的钠亲和力以及降低的扩散势垒。这项工作揭示了一种同步解决电导率和寿命缺点的方案，这对SIBs系统中基于TMSe的阳极开发具有启发性。
