Research progress on direct borohydride fuel cells

The rapid development of industry has accelerated the utilization and consumption of fossil energy, resulting in an increasing shortage of energy resources and environmental pollution. Therefore, it is crucial to explore new energy storage devices using renewable and environment-friendly energy as fuel. Direct borohydride fuel cells (DBFCs) are expected to be a feasible and efficient energy storage device by virtue of the read availability of raw materials, non-toxicity of products, and excellent operational stability. Moreover, while utilizing H₂O₂ as an oxidant, a significant theoretical energy density of 17 kW h kg^-1 can be achieved, indicating the broad application prospect of DBFCs in long-range operation and oxygen-free environment. This review summarizes the research progress on DBFCs in term of reaction kinetics, electrode materials, membrane materials, architecture, and electrolytes. In addition, we predict the future research challenges and feasible research directions, considering both performance and cost. We hope this review will help guide future studies on DBFCs.