School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY, 14853, USA.
Department of Material Science and Engineering, Cornell University, Ithaca, NY, 14853, USA.
Angew Chem Int Ed Engl. 2017 Oct 9;56(42):13070-13077. doi: 10.1002/anie.201707754. Epub 2017 Sep 8.
Rechargeable batteries based on metallic anodes are of interest for fundamental and application-focused studies of chemical and physical kinetics of liquids at solid interfaces. Approaches that allow facile creation of uniform coatings on these metals to prevent physical contact with liquid electrolytes, while enabling fast ion transport, are essential to address chemical instability of the anodes. Here, we report a simple electroless ion-exchange chemistry for creating coatings of indium on lithium. By means of joint density functional theory and interfacial characterization experiments, we show that In coatings stabilize Li by multiple processes, including exceptionally fast surface diffusion of lithium ions and high chemical resistance to liquid electrolytes. Indium coatings also undergo reversible alloying reactions with lithium ions, facilitating design of high-capacity hybrid In-Li anodes that use both alloying and plating approaches for charge storage. By means of direct visualization, we further show that the coatings enable remarkably compact and uniform electrodeposition. The resultant In-Li anodes are shown to exhibit minimal capacity fade in extended galvanostatic cycling when paired with commercial-grade cathodes.
基于金属阳极的可充电电池引起了人们的兴趣，因为它们可以深入研究固液界面处液体的化学和物理动力学。采用简便的方法在这些金属上形成均匀的涂层，以防止与液态电解质发生物理接触，同时实现快速离子传输，这对于解决阳极的化学不稳定性至关重要。在这里，我们报告了一种简单的化学镀离子交换方法，用于在锂上形成铟涂层。通过联合密度泛函理论和界面特性实验，我们表明铟涂层通过多种过程稳定了锂，包括锂离子的异常快速表面扩散和对液态电解质的高化学稳定性。铟涂层还与锂离子发生可逆的合金化反应，这有利于设计高容量的混合铟-锂阳极，该阳极可以同时采用合金化和电镀方法进行电荷存储。通过直接可视化，我们进一步表明，该涂层可以实现非常紧凑和均匀的电沉积。当与商业级阴极配对时，所得到的铟-锂阳极在延长的恒电流循环中表现出最小的容量衰减。
