Mechanofusion-derived cathode composite microstructures with scalable mixed conducting matrix coatings for solid state batteries.

Kissel, Maximilian; Frankenberg, Finn; Demuth, Thomas; Lai, Anton; Laser, Niklas; Wagner, Daniel; Eisa, Ahmed; Michalowski, Peter et al. · Nat Commun · 2026

basic_science · Level V

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Abstract

The successful implementation of solid state batteries not only requires the use of high-capacity anodes, but also high-performance composite cathodes. However, the production of solid state battery cathode composites with optimized microstructures remains a significant challenge, especially for large-scale fabrication. Here, we present a scalable high-intensity dry mixing process to create tailored functional coatings on single-crystalline LiNi<sub>0.82</sub>Mn<sub>0.07</sub>Co<sub>0.11</sub>O<sub>2</sub> via mechanofusion. We investigate the coating of LiNi<sub>0.82</sub>Mn<sub>0.07</sub>Co<sub>0.11</sub>O<sub>2</sub> with the malleable halide solid electrolyte Li<sub>3</sub>InCl<sub>6</sub> under various process conditions, linking process parameters obtained from discrete element method simulations with experimentally accessible morphological properties to offer guidelines for further optimization. In this way nanometer-thin covering coatings as well as thick matrix coatings are successfully produced. Incorporating carbon black into the thick matrix coating results in well-performing mixed conducting matrices that can be used directly as composite cathodes without further treatment. The compositions investigated enable stable cycling with a specific capacity of up to q<sub>comp</sub> = 100 mAh g<sup>-1</sup> (based on the total mass of the composite cathode) at a C-rate of 1 C (60 min). While higher carbon black content is observed to improve CAM utilization, excessive amounts are detrimental for cell kinetics and chemo-mechanics, emphasizing the importance of the cathode mixing process and composition on overall cell performance.