It’s not only the power stored in batteries that is important, but a battery’s staying power, size, weight and ability to charge up quickly – not to mention the cost. Another important factor is safety. The elements used in batteries can be dangerous to handle, but people who use them don’t usually come into contact with these elements. However, if a battery degrades and is touched it can cause an acid burn. Also some elements in some batteries are flammable.
There are many different kinds of batteries and it’s important to get the right one for the job. Experts are working constantly on new technology to improve batteries – we've all seen the giant leaps forward in innovation over the last decade. This is an ongoing scenario with constant improvements - both big and little - all of which are important in the general scheme of things.
Technology is not the only consideration when it comes to improvements in batteries. It also has to be mixed with other factors such as affordability, lightness and the amount of deliverable power in each battery. Cosmos Magazine detailed a number of the latest trends in batteries which we've summarised below.
Regarded as the champ of batteries, the lithium ion can be used for just about everything; from cars to small appliances and your household solar power supply. In fact, they have the potential to allow home-owners with solar power to make considerable savings. While the technology used in these batteries is mature and reliable, there are some safety concerns. Airline passengers are warned of the risk of fire, especially if appliances containing lithium ion batteries are stored in the luggage section, where a fire can break out unnoticed until it’s too late. It is better to keep such devices in the cabin where the risk can be minimised.
However, aeroplanes also use lithium ion batteries as back-up for ground maintenance and to provide electricity during flight, as well as for back-up power of other important in-flight functions. In 2013 they overheated due to a chemical reaction called thermal runaway, and caused fires in a Boeing 787. It wasn't just the fault of the batteries; certain other issues played a part in the problem. For instance, during the investigation, Boeing and the Federation Aviation Authority (FAA) found 17 non-compliance issues, some to do with the battery manufacture, but others to do with outsourcing the manufacture of certain airplane parts. With the latter, certain changes to the design and assembly of components were made without being okayed by Boeing first. While these issues did play a part in the fire, it’s hoped that a replacement will be found for the flammable component in these batteries and with a little tweaking the new ones will be even better.
According to Cameron Shearer, materials engineer at Flinders University in Adelaide, the lithium sulphur battery will be the next commercial battery that may even replace the lithium ion battery. Why? It‘s more energy dense, with the potential to hold five times more energy than the lithium ion battery. It will potentially be suitable for small appliances, cars and household power supplies. The lithium sulphur battery uses lithium instead of granite to catch the lithium ions at the anode, while at the cathode, sulphur is used instead of a mix of metals. This makes it a much lighter battery – the only downside is that it doesn't have a long life due to the sulphur degrading and clogging up the works. Once a viable solution for this has been found this battery could shoot to the top of the list. In fact, chemists at the Toyota Research Institute of North America in Michigan are working on a polymer coating to stabilise the sulphur.
It’s always good when something that is freely available can be used in a project. The lithium air battery is so called because it uses oxygen straight from the air, rather than sulphur to soak up the spent ions. This oxygen is exhaled as the battery is re-charged, making it the lightest battery yet. It can be used in devices and electric cars and has the potential to contain ten times more energy than the lithium ion battery. The main disadvantage is that it has a very short life span – so far. In fact, this battery has yet to move off the lab bench as it needs several elements to be improved before it’s suitable for commercial use. When that finally happens it may be the best battery of all.
If you don’t mind weight and size, a cheaper battery that uses sodium rather than lithium is available for solar energy storage. The sodium ion battery also has the potential for use in cars and devices, but so far can only be used for applications where size is not a problem. The main disadvantage is that of poor performance, at least when compared with the lithium ion battery.
Last but not least is the flow battery which is ideal to store renewable energy. While it’s cheap and reliable, it can only be used for stationary applications due to using two tanks of electro-active liquids to shuttle the electrons between. Since the smallest of these batteries is the size of a bar fridge, you can understand that they are hardly suitable for appliances or even cars. But they are useful for places where size is not important. They’re great for use in remote locations such as mining sites. They could also be used for energy storage in the home by situating them behind a wall or somewhere that they can remain invisible.
As technology improves and delivers different and improved methods of making things, it’s highly likely that batteries will benefit. Even now techniques for high resolution microscopy are enabling scientists to custom design better and smaller battery components. So cool! Stay tuned on this one.