We all use lithium-ion (Li-ion) batteries these days – it sometimes seems difficult to purchase something that doesn’t use them. So there must be many upsides to using them!
The major advantages can be summarized quickly:
- Higher specific energy
- Higher energy density
- Higher energy efficiency
- Longer cycle life
- Longer calendar life.
No wonder they have become very popular!
But like everything else in life, there are downsides to Li-ion batteries.
Let’s start by looking at the lithium metal itself and some of its historical uses.
Lithium is in the same group as sodium in the periodic table. We all remember one of the dramatic chemistry experiments our teachers conducted in our school days – placing a small pellet of sodium in water – an explosive response!
Well, lithium does the same thing. In chemical terms, lithium plus water gives lithium hydroxide and hydrogen – explosively!
Now, obviously, this doesn’t happen in the wild simply because lithium doesn’t exist as the pure metal in the wild. In fact, lithium is a relatively unstable metal and is highly reactive. It is the least dense metal and the least dense solid element. So while we do not encounter pure lithium in the wild, it is important to remember that lithium can be dangerous.
Historically lithium compounds were used as mood stabilisers, but this use fell out of favour in the 1940s due to its side effects.
Now lithium and its compounds are used for things like heat-resistant glass and ceramics, lubricants, flux additives for iron, steel and aluminium production – and, of course, batteries.
Interestingly, lithium-ion batteries do not contain that much lithium. Back in 2016 Elon Musk described lithium as “the salt in your salad” – meaning that other metals (nickel especially) are used at much higher levels in these batteries. For example, up to 80% of the lithium battery by weight can be nickel, while lithium will be around 10%.
In terms of distribution, most of the lithium resources are in South America (Argentina, Chile, Bolivia), but Australia is also very important. Western Australia has 5 of the world’s biggest lithium deposits.
An important difference between Australia and the other major producers is the method used to mine the metal. In most countries salt-flat brines are used, but in Australia it is produced from hard-rock deposits, which is somewhat more environmentally friendly.
The downsides of lithium batteries start with the mining of the lithium and the other metals required. Salt-flat brine technologies, for example, produce all sorts of very damaging by-products as well as being poisonous to local fauna and flora.
But obviously the biggest issue with lithium batteries is their explosive fire potential. Most of these batteries available on the market today typically contain a liquid electrolyte solution with lithium salts dissolved into a solvent to create lithium ions. While it is the presence of these ions that yields the superior battery performance, it also creates a highly volatile and flammable mixture – particularly at higher temperatures. To complicate this, the way the battery produces power also generates heat as a by-product. Under thermal runaway conditions, excessive heat promotes this chemical reaction, thus creating even more heat in an ever increasing spiral.
One of the simplest ways to prevent thermal runaway is to store batteries at safe temperatures – for most lithium batteries this is between 5 and 20o C.
Lithium batteries can also catch fire if subjected to high-pressure levels – e.g. being punctured or crushed. This can happen if the device containing the battery is dropped or impacted in some way.
Warning signs to look for:
- If the shape of the battery has changed or looks swollen, stop using it immediately.
- Failing lithium batteries tend to make hissing or cracking sounds.
- If you detect a strong or unusual odour coming from the battery, stop using it immediately.
- The most obvious one is smoke – this indicates a fire has already started.
Fires caused by lithium batteries can be dangerous and difficult to extinguish. These fires burn differently from ordinary fires because they can keep flaring up again and again. This means that once the original fire has been extinguished, the battery needs to be kept cool for hours afterwards.
How to put out a lithium battery fire:
- Call emergency services immediately.
- Professionals recommend using a specialised extinguishing agent like the F-500 Encapsulator Agent.
- CO2 fire extinguishers will not be effective.
- Water is probably the easiest thing to use – but enormous amounts are required. The goal here is to cool the battery pack and thereby stop the thermal runaway.
Disposal of lithium batteries is also a problem. For example, fires in landfill and battery-recycling facilities have been attributed to the inappropriate disposal of Li-ion batteries.
How should you dispose of them? Call your local council for their best advice. Do not place them in your normal waste or recycling bins.
Will lithium batteries be phased out?
All indications are that they are here to stay. Improved battery types are being developed and they will become safer.
However, keep an eye on graphene batteries – they could be a serious disrupter in time. Graphene is a sheet of carbon atoms bound together in a honeycomb lattice pattern. It is a potent conductor of electrical and thermal energy, extremely lightweight, chemically inert, and flexible with a large surface area. It is also considered eco-friendly and sustainable. They are in an early stage of development.
But for the immediate future, it will be hard to beat lithium batteries for all the reasons stated at the beginning of this article. We just need to be aware of the risks and treat them with respect – not like we tend to treat traditional lead-acid batteries.
