Carbon felt modified with copper sulfide nanoflowers as a high-performance electrode for polysulfide–ferrocyanide redox flow batteries
摘要
The development of efficient and cost-effective energy storage systems is crucial for addressing the intermittency of renewable energy sources. Redox flow batteries (RFBs) have emerged as promising candidates for large-scale energy storage due to their scalability and flexibility. However, the sluggish kinetics of polysulfide redox reactions at conventional carbon-based electrodes limit their performance. In this study, we report a novel copper sulfide (CuS) nanoflower-modified carbon felt (CuS-CF) electrode for polysulfide–ferrocyanide redox flow batteries (PFRFBs). The CuS nanoflowers were synthesized via a low-temperature water bath method, exhibiting a highly ordered hexagonal crystal structure with minimal defects. The CuS-CF composite electrodes demonstrated superior electrochemical performance, including enhanced conductivity, reduced overpotential, and improved reversibility of polysulfide redox reactions. At a current density of 120 mA cm−2, the CuS-CF composite electrodes achieved an energy efficiency of 68.9%, significantly outperforming the pristine CF electrode. Long-term cycling tests revealed excellent stability, with minimal capacity decay over 2000 cycles. These results highlight the potential of CuS-CF composite electrodes as high-performance, cost-effective solutions for large-scale energy storage applications.