Metal halide perovskites (MHPs) have shown remarkable potential for energy storage, with previous studies demonstrating exceptional stability enabled by protective coatings (e.g. TiO₂) on thin films [1, 2, 3]. However, translating these promising results from lab-scale demonstrations to practical coin cells with high-mass-loading electrodes presents a formidable technological challenge. At these scales, maintaining material integrity becomes critical, as uniform protective coatings via physical deposition are less feasible, and the electrode fabrication process itself can introduce severe instability.

In this work, we present a comprehensive investigation into the stability of all-inorganic lead-based (CsPbBr₃) and lead-free (Cs₂AgBiBr₆) perovskites in the context of high-loading anodes without external protective layers. We reveal that the conventional slurry-casting method -the standard protocol in battery research- is fundamentally incompatible with these sensitive materials. Through detailed structural characterization (XRD, SEM-EDS), we demonstrate that the synergistic effect of the polar solvent (NMP) and the mechanical grinding by carbon black additives induces catastrophic mechanochemical degradation.  Specifically, the carbon black acts as a grinding medium that exposes defect-rich surfaces, facilitating chemical attack by NMP. This leads to the leaching of lead and the precipitation of inactive byproducts, such as Cesium Bromide (CsBr), even before the battery is assembled or cycled.

To overcome this fabrication-induced degradation, we propose and demonstrate a solvent-free dry-processing technique utilizing hot roll-pressing. This approach successfully preserves the pristine crystalline phase of the perovskite in bulk electrodes. Electrochemical analysis confirms that the resulting dry-fabricated CsPbBr₃ anodes exhibit distinct differential capacity peaks corresponding to a reversible Li-Pb alloying mechanism, a behavior that is obscured in slurry-cast electrodes due to high polarization and material loss. Furthermore, we extended this methodology to lead-free double perovskites (Cs₂AgBiBr₆), elucidating a complex multi-phase storage mechanism involving Li-Bi and Li-Ag alloying.

Despite the preservation of the crystal structure during fabrication, the dry-processed anodes still exhibit capacity fading over prolonged cycling, attributed to active material loss and volume expansion in the absence of a confinement layer. Our findings confirm that while dry-processing is a prerequisite for fabricating functional high-loading perovskite anodes, it does not eliminate the need for interface engineering. This study ultimately underscores that achieving the long-term stability previously observed in protected thin films requires the development of scalable, chemically compatible protective strategies that can be integrated into bulk electrode manufacturing.