Understanding how spatial heterogeneity governs ionic transport is essential for advancing solid polymer electrolytes. In this work, impedance spectroscopy, photoluminescence and field-resolved electrostatic simulations are employed to investigate chitosan-lithium perchlorate solid biopolymer ionogel electrolytes (SPIEs) embedded with 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid across a wide composition range ( \(\:\varphi\:\) = 0-0.60). The ionic conductivity exhibits a nonlinear, non-monotonic dependence on \(\:\varphi\:\) , attaining a pronounced maximum near \(\:\varphi\:\) ≈ 0.45 where enhanced photoluminescence and elevated thermal stability reveal the formation of interconnected ionic liquid-rich domains. A hybrid transport framework combining thermally activated hopping, percolation-assisted conduction and cluster-induced suppression quantitatively reproduces this trend, establishing network connectivity as the dominant factor governing correlated charge transport. Field-resolved simulations of electric field and current density distributions reveal the emergence of spatially continuous, electrostatically coherent conduction pathways near the percolation threshold, followed by their fragmentation into spatially heterogeneous ion-rich clusters associated with reduced transport efficiency at higher ionic liquid loadings. This work establishes a unified framework that connects spatial connectivity and electrostatic coherence to macroscopic ionic transport, providing a basis for the rational design of efficient biopolymer-based solid ionogel electrolytes.
