Constructing a novel closed-loop and efficient pathway for multi-functional CO2 utilization in concentrated solar power systems

• A novel closed-loop, multi-functional CO 2 utilization pathway is proposed. • Thermo-electric chemical cycle realizes hybrid thermal-electrical energy storage. • Total RTE: 52.28 %, relative increase of 51.58 %; Exergy efficiency: 53.47 %. • The LCOE decreased by 40.42 %, reaching 94.55 $/MWh. In concentrated solar thermochemical cycles, CO 2 utilization enables both energy storage and release. However, the high energy consumption associated with CO 2 compression has limited the overall performance of solar power generation. In this work, an energy storage system coupling thermochemical and electrochemical cycles is proposed. This system constructs a “heat storage − electricity storage − electricity release − heat release” closed-loop path for the multi-functional utilization of CO 2 , achieving efficient and low-cost green power production. Energy analysis showed that the thermoelectric cycle coupling enabled the thermochemical subsystem to achieve a round-trip efficiency of 37.78 %, which represented a relative increase of 9.54 % compared to the conventional thermochemical system. Furthermore, the peak round-trip efficiency of the electrochemical subsystem is 74.70 %. The hybrid system achieved a maximum round-trip efficiency of 52.28%. Exergy analysis revealed that the thermochemical subsystem achieved an exergy efficiency of 41.55 %. The hybrid system achieved an exergy efficiency of 53.47%, with a relative increase of 28.69 %. Economic analysis showed that the hybrid system achieved the levelized cost of 94.55 $/MWh, representing a reduction of 40.42 % compared to the conventional thermochemical storage system. Therefore, this hybrid system has great potential for the multi-functional utilization of CO 2 .