Tin Modified Carbon Nanofibers as an Effective Catalytic Electrode for Bromine Redox Reactions in Static Zinc-bromine Batteries

Zinc-bromine batteries (ZBBs) have emerged as a compelling solution for large-scale energy storage, yet they confront significant technical challenges impeding widespread commercialization. The electrochemical processes within ZBBs rely on a stoichiometric mechanism, where the bromine reaction at the cathode drives the zinc plating reaction on the anode. However, the sluggish electrochemical kinetics of Br₂/Br⁻ redox reactions lead to substantial electrochemical polarization, resulting in interruptions in zinc plating and significant voltage losses in ZBBs. This study introduces a new solution to address these challenges by leveraging carbon nanofiber decorated with tin nanoparticles as an efficient catalyst. The catalyst serves to enhance the Br₂/Br^– redox reaction, effectively reducing voltage losses in ZBBs. When implemented in static ZBB configurations, the Sn/CNF catalysts demonstrate exceptional long-term stability, achieving an impressive 3000 cycles with minimal voltage loss. In contrast, ZBBs utilizing SnO₂ based catalysts experience a substantially higher voltage loss of 736 mV, along with limited and unstable cycling performance. These findings signify a promising approach for the development of catalytic electrodes, paving the way for high-performance ZBBs with improved efficiency and cycling durability.