Real World Uses
Metal-air batteries are already in use- Zinc-air hearing aide batteries are an example. In fact research into metal-air batteries started over 25 years ago. The renewed interest in this time of chemical batteries is due to advances that allow large amounts of aluminum alloy to be produced at very low costs. Who is interested in this technology? The American military, hybrid car manufacturers, third world countries, and makers of portable electronic devices top the list.
The initial American military research focused on creating reliable, lightweight power sources for military and space applications. Because weight and battery life were the main concerns, aluminum became the best choice for the metal "fuel" since it is lightweight, has a very high energy density, and is recyclable. Unfortunately the first aluminum air batteries were very expensive to produce and only found limited application in underwater vehicles and in Special Forces long term emergency packs. Today the military has reinvested in this technology hoping to develop lightweight “personal power stations" that can be carried by ground soldiers as a way of charging and running integrated computer and communication devices while in the field.
Car manufacturers are always looking for ways to reduce the weight of a vehicle without compromising performance or safety. Having a lightweight, high power battery system could potentially reduce the weight of a vehicle up to 500 lbs. and make electricity a viable power source for hybrid engines. Many car companies are looking at Lithium Air batteries, but Toyota has experimented with a Nickel Aluminum air battery that has the potential of reducing the weight of its Prius over 750 lbs.
Some personal aluminum-air fuel cells have the potential to be up to 75 times more energy dense than lithium-ion fuel cells meaning that laptops, cell phones, PDA’s, tablet computers and all other types of personal entertainment devices could use more of their footprints for components and less for battery, reducing the weight and increasing performance.
The most intriguing place that this technology could (and should) be used is in developing regions of the world that do not have ready access to electric grids. Aluminum air battery research has led to the development of large battery banks that could be used to power sanitation and building efforts in third world countries. This can include simple water purification systems, medical diagnostic tools, and even power to whole houses or communities until an infrastructure can be put into place.