Hamad Bin Khalifa University , Qatar Environment and Energy Research Institute, Qatar Foundation , Education City , Doha 34110 , Qatar.
ACS Appl Mater Interfaces. 2018 Apr 25;10(16):13509-13518. doi: 10.1021/acsami.8b01104. Epub 2018 Apr 16.
The transition-metal disulfide (MoS) is a fantastic material used in diverse fields of applications. Ionic diffusivity and interfacial exchange current density are model parameters that play a crucial role for the optimization of device performances, which are not clearly known for this material. The additive-free dense film of MoS has been deposited by a facile electrodeposition approach and characterized by structural, morphological, and compositional analyses. This report provides the characterization of interfacial charge-transfer kinetics and diffusion of lithium ion in the MoS films as a function of lithium concentration at 25 °C temperature. The interfacial exchange current density is observed to be varied barely, ∼0.069-0.066 mA/cm, with the change of lithium content, from x = 0.01-0.25, in Li MoS. The ionic diffusivity of the film is found to be in the range of ∼3 × 10-10 cm s and does not vary much with the measured lithium concentration window. The electrochemical performances of the material are limited by the transport of lithium ion and interfacial kinetics over the measured state of lithium content. A submicron-size particle with high surface area is needed to be used as an electrode of the material for practical C-rates.
过渡金属二硫化物(MoS)是一种应用广泛的理想材料。离子扩散率和界面交换电流密度是优化器件性能的重要模型参数,但对于这种材料来说,这些参数并不明确。本研究通过简便的电沉积方法制备了无添加剂的 MoS 致密膜,并通过结构、形态和成分分析对其进行了表征。本报告提供了 MoS 薄膜中锂离子的界面电荷转移动力学和扩散特性随温度为 25°C、锂浓度变化的研究结果。结果表明,在 LiMoS 中,随着锂含量从 x = 0.01 变化到 0.25,界面交换电流密度几乎没有变化,约为 0.069-0.066 mA/cm。薄膜的离子扩散率在 3×10-10 cm s 的范围内,且随测量的锂浓度窗口变化不大。该材料的电化学性能受到测量锂含量状态下锂离子传输和界面动力学的限制。需要使用具有高表面积的亚微米尺寸颗粒作为该材料的电极,以实现实际的 C 率。