Tagliaferri Stefano, Nagaraju Goli, Sokolikova Maria, Quintin-Baxendale Rachael, Mattevi Cecilia
Department of Materials, Imperial College London, London SW7 2AZ, UK.
Nanoscale Horiz. 2024 Apr 29;9(5):742-751. doi: 10.1039/d3nh00576c.
Miniaturized aqueous zinc ion batteries are attractive energy storage devices for wearable electronics, owing to their safety and low cost. Layered vanadium disulfide (VS) has demonstrated competitive charge storage capability for aqueous zinc ion batteries, as a result of its multivalent states and large interlayer spacing. However, VS electrodes are affected by quick oxide conversion, and they present predefined geometries and aspect ratios, which hinders their integration in wearables devices. Here, we demonstrate the formulation of a suitable ink for extrusion-based 3D printing (direct ink writing) based on micro flowers of layered VS obtained using a scalable hydrothermal process. 3D printed architectures of arbitrary design present electrochemically active, porous and micron-sized struts with tuneable mass loading. These were used as cathodes for aqueous zinc-ion battery electrodes. The 3D printed VS cathodes were assembled with carbon/zinc foil anodes to form full cells of zinc-ion, demonstrating a capacity of ∼1.98 mA h cm with an operating voltage of 1.5 V. Upon cycling a capacity retention of around 65% was achieved after ∼100 cycles. The choice of the electrolyte (a water-in-salt electrolyte) and the design of the pre-processing of the 3D printed cathode ensured improved stability against dissolution and swift oxidation, notorious challenges for VS in an aqueous environment. This works paves the way towards programmable manufacturing of miniaturized aqueous batteries and the materials processing approach can be applied to different materials and battery systems to improve stability.
小型化水系锌离子电池因其安全性和低成本，是可穿戴电子产品中极具吸引力的储能装置。层状二硫化钒（VS）由于其多价态和较大的层间距，在水系锌离子电池中展现出了具有竞争力的电荷存储能力。然而，VS电极受到快速氧化转化的影响，并且它们具有预定义的几何形状和纵横比，这阻碍了它们在可穿戴设备中的集成。在此，我们展示了一种基于通过可扩展水热法获得的层状VS微花，用于基于挤出的3D打印（直接墨水书写）的合适墨水的配方。任意设计的3D打印结构呈现出具有可调节质量负载的电化学活性、多孔且微米级的支柱。这些被用作水系锌离子电池电极的阴极。3D打印的VS阴极与碳/锌箔阳极组装形成锌离子全电池，在1.5V的工作电压下展示出约1.98 mA h cm的容量。在循环约100次后，实现了约65%的容量保持率。电解质（盐包水电解质）的选择和3D打印阴极的预处理设计确保了在水性环境中对VS来说臭名昭著的溶解和快速氧化挑战方面具有更高的稳定性。这项工作为小型化水系电池的可编程制造铺平了道路，并且这种材料加工方法可应用于不同的材料和电池系统以提高稳定性。
