Metal-Redox Bicatalysis Batteries for Energy Storage and Chemical Production

New types of electrochemical energy conversion and storage devices based on redox electrocatalytic reactions possess great potential in renewable energy to maximize energy utilization and balance environmental issues. The typical device is the metal-redox bicatalysis battery, where the cathode is redox bifunctional catalyst (named as redox bicatalyst) with gas, solid, liquid as active reactants while anode is metal, driven by cathodic redox electrocatalytic reactions during charge/discharge processes, which promotes the energy storage and chemical production. In this system, the metal anode, redox-bicatalyst cathode, electrolytes, and the redox electrochemical reactions can be modified and adjusted to achieve the optimal energy conversion and utilization. Therefore, the deep understanding of the electrochemical system is conducive to designing new devices to meet the demand among various applications, including energy storage and conversion. In this review, the authors clarify the fundamentals and design principles of the rechargeable/reversible metal-redox bicatalysis batteries and how each part affects the devices in energy conversion and chemical production. The authors summarize the electrocatalytic reduction/oxidation reactions, the reported systems relied on redox reactions, and the corresponding redox bicatalysts. Finally, a perspective of the key challenges and the possible new types of metal-redox bicatalysis batteries for efficient energy utilization and chemical production are given.