The Need

Potassium-air batteries have recently emerged as alternative energy storage devices beyond lithium-ion batteries. However, potassium metal anodes suffer from poor reversibility during plating and stripping processes due to their high reactivity and unstable solid electrolyte interphase (SEI). It is well known that dendrite formation on the surface of the potassium anode is the leading cause of poor reversibility. Dendrites pose a significant problem because they can cause shortages between different chambers of the battery leading to high power loss. A method is needed to combat the growth of dendrites in potassium batteries.

The Technology

Dr. Yiying Wu and his research team at The Ohio State University have developed a novel electrolyte system for potassium batteries, using potassium bis(fluoroslufonyl)imide (KFSI)- dimethoxyethane (DME), for use in a potassium air battery which inhibits the growth of dendrites. This electrolyte forms a uniform solid electrolyte inter-phase with 99% efficiency at ambient temperatures. The potassium anode has been shown stable up to 5 V, compared to K/K⁺. This breakthrough by Dr. Wu and his team is based on their theoretical calculations that a potassium air battery could have a specific energy of 935 Wh/kg².

Commercial Applications

• Next gen power grids
• In home energy storage
• Electric vehicles
• Phone batteries

Benefits/Advantages

• Potassium is more abundant than lithium, making it more cost effective
• Batteries can be made larger because both the material and process are cheaper than lithium ion batteries
• High efficiency
• Dendrite-free feature is favorable for preventing short-circuit of the battery