What’s Up With Lithium Batteries?
There’s almost no way you haven’t heard about lithium batteries. They’re in everything now, from bathroom scales to electric cars. It’s also likely you’ve heard some horror stories in the news about smartphones exploding in people’s faces or in their pockets. Lithium batteries catch fire on planes – sometimes it’s the planes own batteries too!
So what are lithium batteries? Why do we use them in everything? What do you need to know about them? That’s what I’m going to talk about in this article; by the end you should know all the basic facts about this modern battery technology. Enough to make sure you don’t get caught out by the pitfalls of lithium battery ownership.
What is a Lithium Battery?
Simply put, a lithium battery is one that uses the metal lithium as a core component. The rechargeable batteries that we all know are actually lithium ion batteries. They use a special chemical mix that contains lithium. Pure lithium metal batteries are possible, but since lithium is a very unstable metal, recharging lithium metal batteries proved far too dangerous for commercial use.
Why Use Lithium Batteries?
Of all the battery chemistry suitable for use in small electronic and electrical devices, lithium batteries have the best power capacity for a given weight. Compared to the previous nickel-cadmium battery technology, you can get nearly twice as much energy for the same battery weight.
This is especially important for electric vehicles, since heavy batteries have a severe negative effect on the power-to-weight ratio. The rise of lithium batteries is what has made the electric car a practical prospect.
Apart from their high power density, lithium batteries also charge much more quickly than other mobile battery technologies. Also, while they still degrade with each recharge, they last for many more cycles than older battery technology.
Researchers also have many promising methods that may one day increase the capacity of lithium batteries, reduce the degradation, and allow them to be charged much more quickly still.
It’s because of these general advantages that lithium ion batteries have essentially taken over as mainstream battery technology.
The Downside To Lithium Batteries
In general, lithium ion batteries are more expensive than other types of batteries. Thanks to the relative volatility of the battery chemistry, they require complex protection circuitry in the battery itself as well as on the part of the charger. This is one of the reasons counterfeit lithium ion batteries are such a problem, since they often have inferior protection systems – if they have any at all! Lithium ion batteries are also pretty hard to manufacture, which is why Sony, LG and Samsung are the world leaders in this arena. They have the technical and financial clout to make safe lithium batteries at a price the market can afford. The same can’t be said for a no-name backyard factory in Shenzen.
While lithium ion batteries don’t suffer from “memory” effects or need periodic discharging like nickel-cadmium batteries do, they do have a problem with aging. If left in storage the batteries should have about a 50% charge, which will help extend the lifespan, but in the end a disused lithium battery will become useless and not hold a charge at all. That being said, the self-discharge rate for these batteries is quite low.
What’s Lithium Polymer?
There is actually a difference between a lithium battery and a lithium polymer battery. Most of the batteries that you’ll encounter are actually lithium polymer or “LiPo” batteries. These batteries are encased in a pouch rather than a solid plastic casing. The electrochemistry of lithium ion and lithium polymer batteries is the same, it’s just the packaging that’s different. Actual LiPo batteries that have a non-liquid polymerized electrolyte (the stuff inside the battery) are not yet available to consumers. So basically lithium ion and LiPo batteries that you can buy today are the same in all but the packaging method.
What’s the Deal With Fires and Planes?
Lithium battery fires are violent affairs and can be hard to put out before they start secondary fires. People into the RC plane and helicopter hobby have many tricks when charging their lithium batteries. Some people charge them in pots or on concrete, where a flameout or explosion won’t do any damage. You can also get a special flame-containment bag. Of course this is only possible if you are charging the battery directly using a special balance charging computer, something that RC hobbyist generally do.
If you buy an e-bike, hoverboard, or some other lithium-powered vehicle, you should charge it in a place where a battery flameout won’t cause secondary fires, such as in a section of the garage that only has bare concrete.
The whole thing with lithium batteries catching fire on airplanes has more to do with the fact that these batteries were being charged at the time; they were part of the plane’s actual system. Lithium batteries can be prone to shorting when charged, which can cause a runaway thermal event, igniting the rest of the battery.
Still, there are regulations preventing the shipping of lithium batteries by air under some circumstances and they are classified as hazardous materials. NEVER ship a defective or recalled lithium battery by air or you could find yourself in hot water with federal law enforcement.
The specific issue with electric vehicles and lithium batteries, apart from charging issues, comes in the form of accidental damage. Puncturing or putting excessive forces on a lithium battery can also cause an explosion or fire. So be very careful around an electric vehicle that’s been in an accident, and never charge a lithium battery that’s swollen or leaking.
If a lithium battery does catch fire you can use an ABC fire extinguisher or water to put out the fire, but be sure to disconnect the power source (if safe to do so) or switch off the main circuit breaker.
However, it’s always the best option to let the fire department deal with a fire, so consider putting it out yourself a last resort.
That’s it! Hopefully you now know that lithium batteries should be treated with caution and respect. Try to charge them in a safe place, and be attentive to swelling, whistling, or smoke. Don’t buy no-name batteries, and check for authenticity certification from device manufacturers. Don’t let large lithium vehicles charge unattended, either.
Armed with this basic knowledge of lithium battery technology you can enjoy your lithium-powered electronics safely.