When half-cells are used to evaluate and understand electrochemical performance and interface properties of a given electrode, the metal electrode size is rarely mentioned. To evaluate such impact on the electrochemical performance and interphase formation, graphite/Li coin cells were used. Undersizing the Li metal electrode led to significantly lower charge/discharge capacities even at C/20 rate due to incomplete lithiation/delithiation processes of the graphite electrode edge. It also led to the formation of non-uniform Li metal deposits as well as to a graphite SEI film with a thickness and composition gradient across the electrode. Oversized Li led, however to homogeneous graphite SEI film. Overall, these results highlight the critical role of the metal electrode size in half-cells and should apply to all half-cells studies using other metal electrodes such as Na, K, Mg.

当使用半电池评估和了解给定电极的电化学性能和界面特性时，很少提及金属电极的尺寸。为了评估这种对电化学性能和相间形成的影响，使用了石墨/锂纽扣电池。由于石墨电极边缘的不完全锂化/脱锂过程，Li金属电极尺寸不足导致即使在C / 20速率下也明显降低了充电/放电容量。这还导致形成不均匀的锂金属沉积物，并导致石墨SEI膜在整个电极上的厚度和成分梯度下降。然而，过大的锂导致形成均质的石墨SEI膜。全面的，