Controlling Diffusion Dynamics Through Additive Electrolyte Chemistry in Flexible Free‐Standing Electrode With Unified 1D‐2D Morphologies

High electronic conductivity and specific capacitance are critical challenges for free‐standing electrodes in neutral electrolyte‐based supercapacitors (SCs). This study introduces a 1D/2D heterostructure electrode composed of reduced graphene oxide/polyaniline/cerium‐metal‐organic framework (rGO/PANI/Ce‐MOF), demonstrating enhanced mechanical strength, flexibility, and electrical conductivity. The integration of rGO into the in situ polymerized PANI and Ce‐MOF facilitates improved charge transport under neutral electrolytic conditions. Additionally, hydrogen bond interactions were engineered using electrolyte additives, propanol, 1,2‐propanediol, and glycerol (Gly) with water molecules to boost ion mobility. The rGO/PANI/Ce‐MOF electrode achieved a specific capacitance of 1180 ± 5% F g − 1 at 2 A g − 1 in 1 M Na 2 SO 4 , which further increased to 1346 ± 5% F g − 1 in a Gly‐modified electrolyte under the same conditions. Density functional theory (DFT) calculations using Na + (H 2 O) 4 clusters provided molecular insights into ion interactions, while distribution of relaxation time (DRT) analysis of electrochemical impedance data revealed improved electrode kinetics. An assembled asymmetric SC delivered 205 F g − 1 , an energy density of 113 ± 5% W h kg − 1 at a power density of 1.1 ± 5% kW kg − 1 , and excellent cycling stability 98% retention. These results underscore the promise of 1D/2D rGO/PANI/Ce‐MOF heterostructures and tailored electrolytes for high‐performance, flexible energy storage in neutral conditions.