In this study, we investigate the strategic spatial integration of a conducting polymer into lithium electrodes for energy storage applications. Poly(3,4-ethylenedioxythiophene) (PEDOT) was incorporated into 2D graphene-molybdenum disulfide (GM) heterolayers to enhance their electrochemical performance in lithium-ion hybrid capacitors (LHCs). Two design strategies were explored: (i) N-PGM with an intra-embedded 3D PEDOT network via vapor-phase polymerization (VDP), and (ii) L-PGM with an outer 2D PEDOT layer deposited in the final fabrication step. N-PGM exhibited improved rate capability over GM, while L-PGM achieved the highest specific capacity and excellent cycling stability, retaining over 95.3% of its capacity after 2000 cycles. PEDOT introduced an additional surface-driven charge storage mechanism, complementing the diffusion-limited redox behavior of MoS₂. Molecular dynamics simulations further revealed that PEDOT weakened direct Li⁺ binding but improved electrolyte compatibility and ion mobility. Notably, the spatial configuration of PEDOT critically influenced these effects: surface-localized PEDOT in L-PGM reduced Li⁺ adsorption energy and promoted faster ion diffusion, whereas embedded PEDOT in N-PGM maintained a balance between ion transport and retention. These findings highlight that spatially controlled polymer incorporation offers a promising route to optimizing ionic accessibility and charge transport in nanostructured electrodes.

Conducting polymers (CPs) have emerged as multifunctional components that modulate electrolyte and separator design for Zn-ion hybrid capacitors, with selected Zn-based battery and alkali-ion systems used as mechanistic references rather than direct performance evidence. Their π-conjugated backbones, tunable doping states, and reversible redox chemistry enable coupled ion transport, interfacial charge regulation, and mechanically compliant ion-conducting environments. However, CP integration also requires careful control of electronic leakage, self-discharge, short-circuit risk, and redox-state-dependent swelling, particularly when CP domains are introduced into separator architectures. This review examines how CP-containing electrolytes and separator-related architectures can regulate ion transport and interfacial charge distribution, provided that continuous electronic pathways are suppressed. In aqueous, quasi-solid gel, solid polymer, and redox-active electrolytes, CP-containing domains are examined in terms of ionic conductivity, Zn²⁺ transport, solvation regulation, and polarization mitigation. In separator-related architectures, spatially confined and electronically interrupted CP domains are discussed with emphasis on ion-flux homogenization, dendrite suppression, electron-blocking requirements, and dimensional stability. Comparative analyses separate directly demonstrated Zn-ion hybrid capacitor behavior from mechanisms inferred from related ion-storage systems. Finally, future directions are discussed for quantitative benchmarking, scalable CP processing, and architecture-controlled CP domains for coordinated electrolyte and separator design.