While Li-ion battery cathode–electrolyte interfaces (CEIs) have been extensively investigated in recent decades, accurately identifying the chemical nature and tracking the dynamics of the CEIs during electrochemical cycling still remain a grand challenge. Here we report our findings in the investigation into the dynamic evolution of the interface between a LiNi_0.33Co_0.33Mn_0.33O₂ (LNMC) cathode and an ethylene carbonate/dimethyl carbonate (EC/DMC)-based electrolyte using surface-enhanced Raman spectroscopy (SERS) performed on a model cell under typical battery operating conditions. In particular, the strong SERS activity provided by a monolayer of Au nanocubes deposited on a model LNMC electrode (additive-free) enables quasi-quantitative assessment of the CEI evolution during cycling, proving information vital to revealing the dynamics of the species adsorbed on the LNMC surface as a function of cell potential. Furthermore, our theoretical calculation, which is based on the interaction between a model interface-bound molecule and a model LNMC surface, agrees with our experimental observation. The carefully designed operando SERS platform has demonstrated high sensitivity, good surface specificity, and excellent compatibility with extensive electrochemical measurements; it is also applicable to fundamental studies of dynamic interfaces in other electrochemical energy storage and conversion systems.

中文翻译：

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锂离子电池中阴极-电解质界面动态演化的Operando研究

尽管近几十年来对锂离子电池的阴极-电解质界面（CEI）进行了广泛的研究，但在电化学循环过程中准确地识别化学性质并跟踪CEI的动力学仍然是一个巨大的挑战。在这里，我们报告了我们对LiNi _0.33 Co _0.33 Mn _0.33 O ₂之间的界面的动态演化的研究结果。（LNMC）阴极和使用表面增强拉曼光谱（SERS）的碳酸亚乙酯/碳酸二甲酯（EC / DMC）基电解质在典型电池工作条件下在模型电池上进行的测试。特别地，由沉积在模型LNMC电极上的金纳米立方单层提供的强大SERS活性（无添加剂）可以对骑车过程中CEI的演化进行定量评估，从而证明了对于揭示吸附在水中的物种的动力学至关重要的信息。 LNMC表面随细胞电位的变化而变化。此外，我们的理论计算（基于模型界面结合的分子与模型LNMC表面之间的相互作用）与我们的实验观察结果一致。经过精心设计的操作性SERS平台具有很高的灵敏度，良好的表面特异性，与广泛的电化学测量具有极好的兼容性；它也适用于其他电化学能量存储和转换系统中动态界面的基础研究。