One of the necessary prerequisites to advance the electrochemical performance of Li₇La₃Zr₂O₁₂ (LLZ) based all-solid-state lithium batteries is the manufacturing of dense composite cathodes from cathode active material (CAM) and the LLZ ceramic solid electrolyte. However, free co-sintering of LLZ and CAM mixtures requires temperatures above 1000 °C which often leads to decomposition and secondary phase formation, especially for high energy CAMs. In our study we present a completely dry processing route which is fast, free of any sintering additives and coatings and suitable to fabricate dense mixed cathodes, pure LLZ separators and multilayers of the two. Through application of high mechanical pressure during Field-Assisted Sintering we were able to reduce the sintering temperature down to 675–750 °C with dwell times as low as 10 min, while still obtaining 95% theoretical density for LCO/LLZ mixtures. The low sintering temperature is suitable for high energy CAMs, but leads to a significant effect of surface impurities, especially from powder handling in air, and affects the crystallinity of the CAM/LLZ interface. In the present paper we investigate the impact of resulting interfaces on the ionic conductivity, the interfacial impedance and the cycling stability of produced cells and propose the optimization strategy.

提升Li ₇ La ₃ Zr ₂ O ₁₂电化学性能的必要先决条件之一基于LLZ的全固态锂电池是由阴极活性材料（CAM）和LLZ陶瓷固体电解质制造致密的复合阴极。但是，LLZ和CAM混合物的自由共烧结需要高于1000°C的温度，这通常会导致分解和二次相的形成，特别是对于高能CAM。在我们的研究中，我们提出了一条完全干燥的加工路线，该路线快速，不含任何烧结添加剂和涂层，并且适合制造致密的混合阴极，纯LL​​Z隔板和两者的多层。通过在现场辅助烧结过程中施加较高的机械压力，我们能够将烧结温度降至675-750°C，停留时间低至10分钟，同时仍获得LCO / LLZ混合物的理论密度的95％。较低的烧结温度适用于高能CAM，但会导致表面杂质（尤其是空气中的粉末处理）产生显着影响，并影响CAM / LLZ界面的结晶度。在本文中，我们研究了所得界面对产生的细胞的离子电导率，界面阻抗和循环稳定性的影响，并提出了优化策略。