Electropolymerized Donor-Acceptor Cathodes for Photoresponsive Li-Dual-Ion Batteries

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.