上海科技大学知识管理系统

Solar redox flow batteries (SRFBs) have shown a great promise for harvesting and storage of solar energy in simple and stand-alone way. The solar-to-redox conversion efficiency during photocharging is the bottleneck for the overall energy conversion efficiency of SRFBs, which is restricted by the photoelectrochemical activitybattery voltage trade-off. By far it remains challenging to unbiasedly photocharge a high voltage (>1.0 V) redox flow battery with a high energy conversion efficiency (>5%) based on a single cost-effective photoelectrode. Herein, we demonstrate a carbon-modified amorphous silicon photoanode to drive a 1.08 V pHneutral TEMPO/quinone-based flow battery for direct photocharging, which delivers an average solar-to-redox conversion efficiency of 6.8 % under simulated solar irradiation, surpassing previous results for the similar types of SRFBs. Combined with high redox-to-electricity conversion efficiency (81.6 %) and high integrating efficiency between photocharging and dark discharge (97.4 %), the as-fabricated SRFB yields an average overall solar-redox-electricity conversion efficiency of 5.4 %, which is seldom achieved by the previous SRFBs. The carbon overlayer on the amorphous silicon surface is identified to be an efficient cocatalyst for PEC oxidation of TEMPO species during photocharging. This work provides an insight to construct highly efficient SRFBs by boosting the photocharging efficiency.