SIUC-Battery preprint (v1)

This preprint introduces the SIUC-Battery architecture, a multi-scale battery concept integrating a hierarchical Solid Electrolyte Interphase (SEI) fabricated via Direct Ink Writing (DIW) prototyping. We propose three novel collective coherence metrics — coherence time (τ_coh), cohesive stress proxy (σ_coh), and coherence exponent (α_coh) — as quantitative proxies to assess interphase stability across large-area electrodes. Experimental thermal and chemical gradients on silicon wafers, combined with physics-informed neural network (PINN) simulations, demonstrate strong position-dependent coherence (y/L normalization) that correlates directly with cycling performance. Key results include: - PINN cycling simulations showing 94.2 % capacity retention after 100 cycles at C/5. - Position-dependent degradation patterns revealed by coherence maps, offering insights beyond conventional bulk tests. The approach leverages Nb₂C MXene-based inks and controlled gradients to enable scalable, high-reliability lithium-based batteries. A multi-phase fabrication roadmap is outlined, targeting >300 Wh/kg energy density, >500 cycles at 80 % retention, and integration of artificial SEI strategies (e.g., FEC/LiTFSI for LiF-rich layers). Preprint version 1.0 — independent research, not peer-reviewed. Comments, feedback and potential collaboration welcome. Keywords: lithium battery, solid electrolyte interphase, SEI, MXene, Direct Ink Writing, DIW, 3D printing, coherence metrics, PINN, hierarchical SEI, battery prototyping