Although gasoline vehicles are getting more efficient, there’s no denying that they still pose some harm to the environment. The future of motoring is electric vehicles.
Electric vehicles are seen as a global saviour, something that can help fix the damage internal combustion has wreaked on the environment. More research and testing is going into developing and improving the components in EVs, but nothing is more important than the car’s battery.
Most EVs currently use a lithium-ion batteries, and some Toyota hybrids use older nickel-metal hydride batteries.
However, despite being used in just about every EV and hybrid, lithium-ion batteries have a low energy density. That means that for their size, they don’t pack much power. Incremental advancements that will bring down the size and cost of lithium-ion batteries are happening, but they won’t help to significantly improve the range of EVs.
On the other hand, lithium-ion batteries have one significant advantage and that’s in regards to recharging — they can be recharged hundreds of times without losing their capacity.
For reference, the benchmark for cars powered by lithium-ion batteries is the Tesla Model S 100D, which uses a 100 kWh battery that enables that car to go 315 miles on a single charge. That’s only possible thanks to a revamp of Tesla’s cooling system that allows the batteries to be run for so long.
But there are alternatives to lithium-ion batteries that could change the way electric cars work in the future, eliminating things like range anxiety, long recharge times, or the need to revamp current technology.
Nanotubes are long microscopic threads that can store and release more ions than a traditional lithium-ion battery. They can discharge and charge faster than most batteries, because, well, they’re not real batteries — they’re more of a supercapacitor. These nanotubes can be layered like sheets and are combined with Graphene (an extremely thin, strong layer of pure carbon) to make a storage system.
Researchers from the Nanyang Technology University (NTU) in Singapore have developed a kind of nanotube-based battery that can reach 70 percent of its charge in two minutes, while being able to last 20 years before deteriorating.
It’s a cutting edge technology that won’t be hitting our roads any time soon. Some are anticipating these batteries to be researched and developed for many more years before even being tested in automotive applications.
One solution to make lithium batteries more energy dense is to use carbon instead of heavier metals. The carbon would react with oxygen to make electricity, but although it’s called lithium air, it’s still a type of battery. IBM has been researching and developing these batteries in order to provide a new type of energy storage for electric vehicles.
In theory, this could help improve the range of EVs, although there are still some kinks to be worked out, including how stable the technology is — it has had some difficulties recharging and is prone to losing its charge through many cycles. Expect it to hit cars as soon as 2020.
Solid State Batteries
Solid state batteries shun the liquid materials used in current lithium-ion batteries and do away with that lithium air idea. Instead, it uses non-volatile materials that are stable at high temperatures. That’s a big deal because extreme temperatures wear out current batteries, which reduces their effectiveness. Solid state batteries, in comparison, would be safer and longer lasting.
Several companies are investing a lot of money into this technology, including Dyson, with the promise that it would bring about more power-dense batteries than we currently have. For example, the current Tesla-Panasonic batteries that are considered to be the benchmark in the EV industry feature a 240 Watt-hour per kilogram specification. Solid state batteries would be somewhere around 400 Wh/kg.
Semi-Solid Flow Battery
There are many unique ideas out there trying to make EVs better. By taking the normal lithium-ion battery and combining it with the theory behind a fuel-cell vehicle, you get a semi-solid flow battery. These work by putting the energy storage material in external tanks, which would mean that storage capacity isn’t limited by the size of the battery itself. This would help improve the costs associated with batteries.
Another way to reduce the costs associated with batteries is to utilize materials and chemicals that are more abundant. Sulfur is such a resource, and is expected to supercede lithium-ion as the go-to battery of choice because of its higher energy density and lower cost.
Lithium sulfur batteries are also supposedly lighter than lithium-ion units, which should help with efficiency and range. Theoretically, they can hold up to three times more energy than a comparable lithium ion battery.