Ever since the very first modern electric vehicle was built, people have been wondering how to get them to travel further – without compromising on cost. Mainstream pure electric cars care barely travel 100 kilometres on one battery charge through electricity, while electric powertrains cost around 50% more than their petrol equivalents.
The answer lies in devising a low-cost, lightweight battery that can power an electric vehicle (EV) over a longer distance before requiring a recharge. Is that so much to ask?
Not necessarily. Over the last decade or so, there’s been a slow but steady advancement in battery technology. But recently, some exciting developments have really got people talking. In 2015, we could be closer to a breakthrough in electric vehicle battery technology than ever before.
Here’s a snapshot of where we are today:
Lithium battery technology has been one of the prime drivers behind electric vehicle development. Lithium-ion batteries are at least three times lighter than lead acid battery counterparts, and three times more powerful. They are comparatively lightweight and capable of being recharged numerous times – all great news for electric vehicles.
New research in lithium batteries tends to focus on three types: Lithium-vanadium-phosphate batteries (also known as vanadium redox flow batteries), lithium-sulphur batteries, and lithium-air batteries. But it’s the first of these, lithium-vanadium-phosphate batteries, which are most likely to be the next big thing in battery storage technology. Their battery density translates into lighter weight electric vehicles, and the higher voltages produced can result in higher speeds and acceleration. The batteries charge faster and more importantly, they have a higher life expectancy than current lithium-ion batteries. Tick, tick, and tick.
That said, IBM is currently exploring lithium-air, or “air-breathing” batteries. They have the same energy density as petrol, which if successfully developed, will extend the travel range of electricity vehicles by up to ten fold.
Solid State Batteries
Arguably the greatest potential for a breakthrough in battery technology lies in the development of solid-state batteries. Unlike lithium-ion batteries, solid-state lithium batteries have no liquid electrolyte and offer much higher energy density – about twice that of the lithium-ion batteries. There’s also no fire risk with solid-state batteries.
But their biggest advantage lies in the manufacturing process, which is similar to existing industrial processes. With economies of scale in production, electric cars would be cheaper to make and buy.
Over in the US, a team at Stanford University has developed an aluminium-ion battery incorporating a graphite cathode. Whilst it’s still in the experimental stage, they have produced some amazing results. Their research holds the potential for making cheap, ultra-fast charging and flexible batteries – with thousands of charge cycles. Plus it’s a safe, non-flammable option with a high charge storage capacity. If it came off, this would be a major breakthrough not only for electric vehicles but also for other sectors, like smart phone technology.
In another remarkable leap, a partnership between aluminium manufacturer Alcoa and Israeli company Phinergy has resulted in the development of a battery capable of powering an electric vehicle for 1,600 kms. The energy comes from a reaction between the aluminium and water when mixed with air (oxygen) in conjunction with a silver based catalyst.
There are a couple of drawbacks though. The prototype aluminium-air battery requires a top-up of water every 3 to 400 kms. And the battery can only be used once – no recharging. Currently, its use is restricted as a supplement to existing lithium-ion battery packs.
University researchers, think tanks and corporations around the world are working hard to push battery technology forward. And if these recent developments are anything to go by, low cost pure electric vehicles could be closer than we think.