Gossage Zachary T, Hui Jingshu, Zeng Yunxiong, Flores-Zuleta Heriberto, Rodríguez-López Joaquín
Department of Chemistry , University of Illinois at Urbana-Champaign , 600 S Mathews Ave. , Urbana , Illinois 61801 , USA . Email:
Chem Sci. 2019 Oct 8;10(46):10749-10754. doi: 10.1039/c9sc03569a. eCollection 2019 Dec 14.
Ions at battery interfaces participate in both the solid-electrolyte interphase (SEI) formation and the subsequent energy storage mechanism. However, few methods can directly track interfacial Li dynamics. Herein, we report on scanning electrochemical microscopy with Li sensitive probes for its , localized tracking during SEI formation and intercalation. We followed the potential-dependent reactivity of edge plane graphite influenced by the interfacial consumption of Li by competing processes. Cycling in the SEI formation region revealed reversible ionic processes ascribed to surface redox, as well as irreversible SEI formation. Cycling at more negative potentials activated reversible (de)intercalation. Modeling the ion-sensitive probe response yielded Li intercalation rate constants between 10 to 10 cm s. Our studies allow decoupling of charge-transfer steps at complex battery interfaces and create opportunities for interrogating reactivity at individual sites.
电池界面处的离子参与了固体电解质界面（SEI）的形成以及随后的能量存储机制。然而，很少有方法能够直接追踪界面锂动力学。在此，我们报道了使用锂敏感探针的扫描电化学显微镜，用于在SEI形成和嵌入过程中的局部追踪。我们追踪了受竞争过程中锂的界面消耗影响的边缘平面石墨的电位依赖性反应性。在SEI形成区域循环揭示了归因于表面氧化还原的可逆离子过程以及不可逆的SEI形成。在更负的电位下循环激活了可逆的（脱）嵌入。对离子敏感探针响应进行建模得出锂嵌入速率常数在10至10厘米/秒之间。我们的研究能够解耦复杂电池界面处的电荷转移步骤，并为探究单个位点的反应性创造机会。
