All-solid-state batteries (ASSBs) are safe, high-energy-storage systems. However, despite the progress achieved in the development of high-ionic-conductivity solid electrolytes (SEs), the power performance of ASSBs remains low because of the high interfacial impedances in composite cathodes. Therefore, understanding the interfacial factors is crucial for obtaining high power ASSBs. This study provides a quantitative analysis of the influence of these factors using impedance spectroscopy measurements, which enables the elucidation of the interfacial impedance values of two key parameters, the grain-boundary resistance (r_i,gb) and charge-transfer resistance (r_i/e). Systematic investigation revealed an unexpected increase in the cathodic resistance with the decrease in the size of the cathode active material (CAM) particles, indicating that even high-reaction-surface-area CAMs yield low r_i/e but high r_i,gb values owing to their high porosity, resulting in a trade-off relationship. In contrast, this phenomenon is unlikely to occur in liquid-electrolyte-based batteries. Notably, we discuss how composite cathode design impacts performances of stable, high-power, and high-energy ASSBs.

中文翻译：

---

制定界面阻抗以设计高能和高功率全固态电池阴极


全固态电池（ASSB）是安全的高能量存储系统。然而，尽管在高离子电导率固体电解质（SE）的开发方面取得了进展，但由于复合阴极的高界面阻抗，ASSB的功率性能仍然较低。因此，了解界面因素对于获得高功率 ASSB 至关重要。本研究使用阻抗谱测量对这些因素的影响进行了定量分析，从而能够阐明两个关键参数的界面阻抗值，即晶界电阻 (r _i,gb ) 和电荷转移电阻（r _i/e ）。系统研究表明，随着阴极活性材料 (CAM) 颗粒尺寸的减小，阴极电阻出人意料地增加，这表明即使是高反应表面积的 CAM，也会产生较低的 r _i/e 但较高的 r _i,gb 值归因于其高孔隙率，从而导致权衡关系。相比之下，这种现象不太可能发生在液体电解质电池中。值得注意的是，我们讨论了复合阴极设计如何影响稳定、高功率和高能 ASSB 的性能。