Elgendy Amr, Papaderakis Athanasios A, Cai Rongsheng, Polus Kacper, Haigh Sarah J, Walton Alex S, Lewis David J, Dryfe Robert A W
Department of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
Henry Royce Institute, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
Nanoscale. 2022 Jul 21;14(28):10125-10135. doi: 10.1039/d2nr02014a.
The development of intrinsically safe and environmentally sustainable energy storage devices is a significant challenge. Recent advances in aqueous rechargeable lithium-ion batteries (ARLIBs) have made considerable steps in this direction. In parallel to the ongoing progress in the design of aqueous electrolytes that expand the electrochemically stable potential window, the design of negative electrode materials exhibiting large capacity and low intercalation potential attracts great research interest. Herein, we report the synthesis of high purity nanoscale Chevrel Phase (CP) MoS a simple, efficient and controllable molecular precursor approach with significantly decreased energy consumption compared to the conventional approaches. Physical characterization of the obtained product confirms the successful formation of CP-MoS and reveals that it is crystalline nanostructured in nature. Due to their unique structural characteristics, the MoS nanocubes exhibit fast kinetics in a 21 m lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) electrolyte as a result of the shorter Li ion diffusion distance. Full battery cells comprised of MoS and LiMnO as negative and positive electrode materials, respectively, operate at 2.23 V delivering a high energy density of 85 W h kg (calculated on the total mass of active materials) under 0.2 C-rate. At 4 C, the coulombic efficiency (CE) is determined to be 99% increasing to near 100% at certain cycles. Post-mortem physical characterization demonstrates that the MoS anode maintained its crystallinity, thereby exhibiting outstanding cycling stability. The cell outperforms the commonly used vanadium-based (VO (B), VO) or (NASICON)-type LiTi(PO) anodes, highlighting the promising character of the nanoscale CP-MoS as a highly efficient anode material. In summary, the proposed synthetic strategy is expected to stimulate novel research towards the widespread application of CP-based materials in various aqueous and non-aqueous energy storage systems.
开发本质安全且环境可持续的储能设备是一项重大挑战。水系可充电锂离子电池（ARLIBs）的最新进展已在这一方向上迈出了重要步伐。在扩大电化学稳定电位窗口的水系电解质设计不断取得进展的同时，具有大容量和低嵌入电位的负极材料设计也引起了极大的研究兴趣。在此，我们报告了通过一种简单、高效且可控的分子前驱体方法合成高纯度纳米级 Chevrel 相（CP）MoS，与传统方法相比，能耗显著降低。对所得产物的物理表征证实了 CP-MoS 的成功形成，并表明其本质上是晶体纳米结构。由于其独特的结构特征，MoS 纳米立方体在 2.1 m 双（三氟甲磺酰）亚胺锂（LiTFSI）电解质中表现出快速动力学，这是由于锂离子扩散距离较短。分别由 MoS 和 LiMnO 作为负极和正极材料组成的全电池在 2.23 V 下运行，在 0.2 C 倍率下可提供 85 W h kg 的高能量密度（基于活性材料的总质量计算）。在 4 C 时，库仑效率（CE）确定为 99%，在某些循环中增加到接近 100%。死后物理表征表明 MoS 阳极保持了其结晶度，从而表现出出色的循环稳定性。该电池优于常用的钒基（VO（B）、VO）或（NASICON）型 LiTi（PO）阳极，突出了纳米级 CP-MoS 作为高效阳极材料的前景。总之，所提出的合成策略有望激发新的研究，推动基于 CP 的材料在各种水系和非水系储能系统中的广泛应用。
