Metal-Air ionic batteries have been examined for their potentially higher energy density than lithium ion-batteries. These batteries have the potential to store up to 11 times more neergy than Lithium-Ion, and can be designed on the same scale, powering everything from personal electronic devices to electric and hybrid vehicles. If this technology proves economically scalable, we may soon see battery powered vehicles with ranges of 400-500 miles on one charge.
With a grant from the Department of Energy, an Arizona State University Materials Science Professor has designed a metal-air ionic battery that use ionic liquids, salts that are liquid at room temperature, sandwiched between a fuel electrode and an air electrode. The fuel eletrode is designed to oxidize a metal-oxide fuel, while the air electrode absorbs and reduces the gaseous oxygen created during oxidation. The fuel stream enters the cnter of the disk, where it flows radially outward and is oxidized on a porous carbon paper electrode coated with platinum nanoparticles. Electrons are conducted through the ionic fluid electrolyte, reacting with the oxidant at the cathode and completing the circuit.
These fuel cell batteries are rechargeable, and this design overcomes some of the premature failure and reduced capacity of previous porous membrane metal air batteries by using a membraneless design. Additionally, the use of a liquid inic eletrolyte instead of an aqueous electrolyte solution prevents the evaporation issues that lead to dendrimer build-up and premature failure. these two technologies combined, reduce the need for excess electrolyte solutions that ultimately reduce the energy storage capacity and reliability of these types of fuel cell batteries. The challenge to make these scalable is to design a cheap metal oxide fuel and create a system that makes their use convenient.
This technology offers the potential to increase the mileage range of battery powered electric vehicles by four or five times current range. This technology also has the potential for use in high energy demand personal electronic devices like cell phones, tablets, and the likes. This will greatly improve the energy density per unit size and weight, significantly reducing the design constraints on thee types of devices.