Fast-Charging Organic Flow Batteries Break the Speed Limit

Self-charging batteries promise to revolutionise our energy networks by integrating storage and conversion into a single unit. However, conventional designs utilising solid-state electrodes face a major bottleneck: the chemical reactions occurring where solids meet gases are sluggish, meaning a full charge typically requires hours. To overcome this, researchers have developed a self-charging organic redox flow battery that leverages the rapid kinetics of liquids.

The performance shift is dramatic. By relying on liquid-phase redox reactions—chemical processes where oxidation states change—the system achieves 94% of its total capacity in a mere eight minutes. Through computational modelling, the team identified that fast 'outer-sphere electron transfer' (a mechanism where electrons hop between molecules without forming a chemical bond) drives this speed.

Durability is equally impressive. Using manganese oxide-based catalysts to minimise unwanted side reactions, the battery maintained nearly 99.98% capacity retention over 1,600 cycles. It proved robust even in harsh conditions, running more than 2,500 cycles at -10 °C. While the proof-of-concept used zinc, the researchers successfully extended the technology to include magnesium and aluminium negative electrodes, offering a sustainable pathway for future energy systems.