Fig. 2: Fabrication process and parameters of co-rolling dry-process.

a Schematic illustrating three fabrication steps (S1-3) and parameters (P1-3). b, c SEM image of positive electrode side of co-rolled film fabricated with (b) large PC-NCM and (c) small SC-NCM. d, e Cross-sectional SEM image of co-rolled film fabricated with (d) 30 °C and (e) 120 °C co-rolling temperatures. f, g Cross-sectional SEM image of co-rolled film fabricated with (f) 100 µm and (g) 20 µm reduction thicknesses. h, i SEM images of as-fabricated and pressed co-rolled film with optimized fabrication parameters and EDS mapping of (h) SSE side and (i) positive electrode side. j Micro-CT reconstruction of co-rolled film.