Electropolymerized Donor–Acceptor Cathodes for Photoresponsive Li‐Dual‐Ion Batteries

ABSTRACT As a novel energy storage method, photo‐assisted rechargeable batteries offer an effective solution to numerous issues currently plaguing organic lithium‐ion batteries. Herein, we propose two donor–acceptor (D–A) structure‐based organic bifunctional electrode materials (TPA‐PTO and CZ‐PTO), which integrates photocatalysis and redox activity. The electropolymerization of D–A conjugated polymer extends π‐conjugation, reduces the molecular bandgap, broadens the light absorption spectrum, and improves intramolecular electron transfer. Specifically, the long exciton lifetimes enable efficient photo‐exciton charge separation and directional charge transfer. Under light irradiation, the photo‐electrodes achieved a capacity of 232 mAh g −1 at 0.2 A g −1 , while the impedance decreased by 50%. Furthermore, the photo‐assisted cell demonstrates remarkable 55% increased capacity at high current density of 10 A g −1 . The exciton transfer dynamic mechanisms of photo‐assisted dual‐ion batteries were also demonstrated by examining the differential effects of light exposure on anion and cation intercalation.