In a groundbreaking step towards sustainable energy, researchers from the University of Cordoba, in collaboration with colleagues from the Polytechnic University of Cartagena, have developed an innovative battery prototype employing hemoglobin. This biocompatible device marks a significant advancement in the realm of electrochemical energy storage.
Hemoglobin, a protein predominantly found in red blood cells, is crucial for transporting oxygen throughout the body. Its high oxygen affinity has made it a subject of interest in various scientific fields. Building on research from the University of Oxford and a project at the University of Cordoba, the researchers explored hemoglobin’s potential in zinc-air batteries, a promising alternative to the prevailing lithium-ion batteries.
Zinc-air batteries, known for their sustainability, use oxygen from the air to generate power. In this new prototype, hemoglobin functions as a catalyst in the oxygen reduction reaction (ORR), a critical process in these batteries. When air enters the battery, hemoglobin facilitates the conversion of oxygen into water at the cathode, thereby releasing electrons that travel to the anode where zinc oxidation occurs.
Manuel Cano Luna, a researcher from the University of Cordoba, explains that hemoglobin’s efficiency as a catalyst stems from its ability to rapidly absorb oxygen molecules and form water molecules. The team’s prototype, with just 0.165 milligrams of hemoglobin, can operate effectively for 20 to 30 days.
This novel battery offers several advantages. Apart from its strong performance, its sustainability stands out, especially in comparison to lithium-ion batteries which are plagued by lithium scarcity and environmental concerns. Moreover, zinc-air batteries are more resilient to adverse atmospheric conditions, a significant advantage over other battery types that require an inert atmosphere during production.
One of the most exciting prospects of this development is the potential application in biomedical devices. The battery’s operation at a pH level similar to that of human blood, coupled with its biocompatibility, makes it an ideal candidate for devices like pacemakers. The fact that hemoglobin is present in almost all mammals further broadens the possibilities for sourcing this protein.
However, the research team acknowledges that there is room for improvement. Currently, the battery is a primary, non-rechargeable type, limiting its scope of application. The team is actively working towards integrating another biological protein capable of transforming water back into oxygen, which would allow the battery to be rechargeable. Additionally, since the battery’s operation depends on the presence of oxygen, its use is restricted to environments where oxygen is available, precluding its application in space.
Published in the journal Energy & Fuels, this research not only presents a novel battery technology but also opens up new possibilities for energy storage solutions. In a world increasingly reliant on mobile devices and committed to renewable energy, there is a growing need for efficient storage of excess electrical energy. This development represents a significant step in addressing these needs while also tackling the environmental and resource challenges associated with current lithium-ion battery technology.