Stalin Sanjuna, Tikekar Mukul, Biswal Prayag, Li Gaojin, Johnson Hillis E N, Deng Yue, Zhao Qing, Vu Duylinh, Coates Geoffrey W, Archer Lynden A
School of Chemical and Biomolecular Engineering, Cornell University, Olin Hall, Ithaca, New York 14853, United States.
Sibley School of Mechanical and Aerospace Engineering, Cornell University, Upson Hall, Ithaca, New York 14853, United States.
Nano Lett. 2020 Aug 12;20(8):5749-5758. doi: 10.1021/acs.nanolett.0c01501. Epub 2020 Jul 2.
Reactive metals are known to electrodeposit with irregular morphological features on planar substrates. A growing body of work suggest that multiple variables: composition, mechanics, structure, ion transport properties, reductive stability, and interfacial energy of interphases, formed either spontaneously or by design on the metal electrode play important but differentiated roles in regulating these morphologies. We examine the effect of fluorinated thermoset polymer coatings on Li deposition by means of experiment and theoretical linear stability analysis. By tuning the chemistry of the polymer backbone and side chains, we investigate how physical and mechanical properties of polymeric interphases influence Li electrodeposit morphology. It is found that an interplay between elasticity and diffusivity leads to an optimum interphase thickness and that higher interfacial energy augments elastic stresses at a metal electrode to prevent out-of-plane deposition. These findings are explained using linear stability analysis of electrodeposition and provide guidelines for designing polymer interphases to stabilize metal anodes in rechargeable batteries.
众所周知，活性金属在平面基底上进行电沉积时会呈现出不规则的形态特征。越来越多的研究表明，在金属电极上自发形成或通过设计形成的多个变量，如组成、力学性能、结构、离子传输特性、还原稳定性和界面相的界面能，在调节这些形态方面发挥着重要但不同的作用。我们通过实验和理论线性稳定性分析研究了氟化热固性聚合物涂层对锂沉积的影响。通过调整聚合物主链和侧链的化学性质，我们研究了聚合物界面相的物理和力学性能如何影响锂电沉积形态。研究发现，弹性和扩散率之间的相互作用导致了最佳的界面相厚度，并且较高的界面能会增加金属电极处的弹性应力，从而防止面外沉积。利用电沉积的线性稳定性分析对这些发现进行了解释，并为设计聚合物界面相以稳定可充电电池中的金属阳极提供了指导。
