The 21st century is placing ever greater demand on our battery needs. The devices we use are becoming smaller and more technologically advanced and this combines with a general demand to be more environmentally friendly. Marrying these two elements is a challenge, both for the devices and for the batteries they use. That technology is in evidence in wider society and it is now easier to find batteries online rather than buying them from a store. Research is looking for ways that will see batteries last for longer and recharge quickly and efficiently. However, research is also looking at ways at adapting them for use with renewable energy. In the same area, battery technology for hybrid and electric vehicles is already advanced and developing apace.
With electric vehicles there is obviously a necessity for knowing how much battery life is remaining when starting or continuing with a journey. So, rather than having a fuel gauge to tell the motorist how much petrol is remaining, electric vehicles include a monitor which shows how much charge there is left in the battery.
In electric car battery technology, developers are looking ahead, away from the lithium-ion batteries of today. While the Li-ion batteries are lighter and reactive and can maximize performance, these properties also carry risks and they are vulnerable to overheating and even catching fire. Therefore, research is concentrating on developing new batteries, one of which is the aluminium-air battery, which, it is hoped, will soon become an established new addition to the metal-air market.
The al-air battery works by oxidizing the aluminium with ambient air and water triggering the reaction in the battery with the electric charge created by the aluminium consumed. The energy is therefore created by the aluminium and its contact with the air. These batteries are “refuelled” by replacing the aluminium anodes and the water supply instead of being electrically recharged as with other types of battery.
Those responsible for its development claim that this new concept will give electric vehicles a range of about 1,000 miles, with the car only needing to have distilled water added approximately every 200 miles, to be fully effective. They have a much higher energy density – about 100 times more than Li-ion batteries – and are appreciatively lighter. The 1,000 mile figure can be explained by the fact that each aluminium plate is able to fuel the car for 20 miles and, because there are 50 plates, this adds up to 1,000.
They are considered attractive in terms of their relatively small environmental impact and they are also inexpensive. However, though metal-air batteries have numerous benefits, there are drawbacks too. Most markedly recharging is a problem area and few manufacturers are able to provide an electrically rechargeable battery.
At present al-air batteries are seen more as a way of increasing the length of electric car journeys rather than being the trigger for much greater use of the vehicle. The hurdles that advocates of aluminium-aid batteries must overcome are doubts over the aluminium being corroded by carbon dioxide released within the battery, the regular refills of water – every 200 miles – and the fact that the plates themselves must be replaced every 12,000 miles. If these issues can be successfully overcome, those developing the al-air batteries are confident that they will revolutionise electric car production.