本项目以太阳能利用、STEP化学过程、超铁电池和太阳能燃料四个热点概念的交集为研究背景，以太阳能高效利用为目标，研究构建新型的Fe(Ⅲ)/Fe(Ⅵ)氧化还原电-燃料联产循环系统。利用太阳能光-热和光-电效应构建高温双池(Double-cell)反应体系，在Cell(I)中阳极将Fe(III)氧化到Fe(VI)，阴极生成H2，Cell(II)中利用CO2的碳捕捉过程生成C和CO，进行充电过程；在放电过程中，Cell(I)中Fe(Ⅵ)放电生成Fe(Ⅲ)，在Cell(II)中将C氧化持续生成CO。具体内容为（1）循环系统理论研究与构建研究；（2）关键技术研究：①Fe(III)氧化到Fe(VI)过程控制，②充电过程CO2还原生成C和CO过程控制和放电过程C氧化生成CO的过程控制。两过程能够在太阳能的驱动下循环进行，构筑了完美的、无污染的电-燃料联产新型太阳能利用系统。

Based on the intersection of four majorities of hot concepts- Solar Energy Utilization, Solar Fuel, Super Iron Battery and STEP (Solar Thermal Electrochemical process), the STEP-framed Solar Energy Rechargeable Cell, characterized with high energy and multi-electron transfer/redox cycle for efficient conversion of solar energy to electric energy combined with the synergistic production of solar fuel, is proposed and established in this application. Double-cell reaction system was constructed with the foundation of photothermal and photoelectric effect. The charging process was first carried out and then the discharging process. The Fe (III) was oxidized to Fe (VI) at the anode and hydrogen gas was generated at the cathode in Cell(I), while C and CO were generated in Cell(II) by the process of carbon capture; The electric energy released while the conversion of Fe (VI) to Fe (III) in Cell(I), while CO was generated continuously in Cell(II) by the process of carbon oxidation. The main contents are as follows :(1)Circulation was constructed by theoretical study and pattern construction.(2)The two key technologies were that the process control of Fe(III) oxidation to Fe (VI) and C oxidation to CO. A perfect pollution-free, sustainable STEP process was established, accomplishing the construction of solar cell-fuel combined cycle system by the cycle operation of charge and discharge process.