Carrier-Regulation in Organic Cathodes for Photochargeable Batteries Boosting High Photoresponse and Long Durability.

Abstract

Photochargeable batteries (PCBs) show promise for sustainable energy conversion and storage, yet face challenges in inefficient photocharging and limited cyclicity, primarily caused by mismatched charge kinetics in the multistep solar-to-electric-to-chemical conversion process. To address this, we introduce a coregulation strategy that integrates a photocathode featuring electron "Acceptor-Acceptor-Acceptor" structure for efficient charge separation (CS), along with ammonium-based carriers exhibiting rapid transfer dynamics to enhance charge utilization in PCBs. When illuminated, the smooth electron pathway in photocathode yields persistent photogenerated charges that are efficiently shuttled by NH₄⁺ carriers to engage in electrochemical processes. Consequently, this multiregulation strategy with orchestrating carriers and photocathodes produces high photocurrent of 31.4 μA cm^-2 and photovoltage of 510 mV cm^-2, thereby enhancing reversible capacity of <i>ca</i>. 29.8%. Moreover, low-corrosive NH₄⁺ enables high photostability of PCB, sustaining cyclability over 800 times. This study introduces carrier/photocathode co-regulation as a transformative demonstration for advancing PCBs, complementing existing photoelectrode optimization frameworks.