Governments, pressure groups even car manufacturers want us to change our fossil fuel burning vehicles, for cleaner, greener electric versions. But for that to happen the alternative needs to become as flexible as what we already have.
Jump in your combustion engine car, fill the fuel tank in minutes and drive 500 miles without even thinking about it. Get behind the wheel of current electric vehicles and you can drive, maybe, 200 miles before having to plug in and wait hours for it to be refuelled. That’s a problem.
But a problem for the general public is a challenge for engineers, and there are solutions being developed that could help us move away from fossil fuels and combustion engines.
A global revolution is taking place in energy storage as firms develop the next generation of batteries that set new benchmarks for charging speed, frequency and environmental friendliness.
One company in particular, NAWA Technologies, has developed the Ultra Fast Carbon Battery, a technology that can be charged and discharged within seconds. And it can do so over a million cycles without any loss in performance. That’s far in advance of conventional lithium-ion batteries which take hours to fully charge and typically have 5,000 cycle limits.
The technology is based on the principle of the ultracapacitor, a high-capacity capacitor with capacitance values much higher than other capacitors, but lower voltage limits, that bridge the gap between electrolytic capacitors and rechargeable batteries.
Traditionally ultracapacitors have been the Usain Bolt of storage devices and the lithium-ion battery a marathon runner. Ultracapacitors can charge and discharge in seconds, great for bursts of energy, while lithium-ion batteries are slower to charge but give out that energy over a longer time. NAWA’s system is capable of storing up to five times more energy than existing ultracapacitors. That could prove a real breakthrough.
The firm has created an ultracapacitor that sits between regular ultracapacitors and lithium-ion batteries. How was it achieved? By using carbon nanotubes with a unique coating.
The nanotube structure imparts an anisotropic topology to the material which helps create a technology with higher power and energy density.
Current power densities for existing ultracapacitors is 100,000W/Kg today but with NAWA’s system that’s expected to reach 500,000W/kg). And energy density, the important aspect for electric vehicles and their range, the increase is targeted at 25Wh/kg compared to today’s 15Wh/kg.
There’s still a long way to go, that leap to 25Wh/kg may sound an impressive figure, but the lithium-ion battery in the Nissan Leaf, one of the best-selling electric vehicles, has an energy density figure of 140Wh/kg.
But it’s the future that could prove far more exciting. In the long term, the possibilities offered by the electrode material could enable the development hybrid ultracapacitor cells with performance levels approaching those of lithium-ion batteries or even advanced lithium batteries that will surpass current lithium batteries in terms of fast charging and lifecycle.
There is a significant difference in the way the batteries store electricity too. In a regular ultracapacitor, there is a purely electrostatic reaction, in a lithium-ion battery there is a purely chemical reaction. But in the new system, the combination of vertically aligned carbon nanotubes, a unique coating and a chemical electrolyte, allows the Ultra Fast Carbon Batteries to sit between regular ultracapacitors and lithium-ion batteries, offering huge potential.
So although there are a lot of ifs and buts, the possibility is there that electric cars could start to rival the vehicles of today for refuelling times using a technology similar to NAWA’s.
In the short term, Ultra Fast Carbon Batteries offer two major solutions. As replacements for existing ultracapacitors, enabling faster charging of electricity. When combined with existing lithium-ion batteries – which boast greater energy density – or hydrogen fuel cells, they can provide more power and extend a product’s lifetime.
Ultra Fast Carbon Batteries could find their way into the automotive industry initially in hybrid cars where they can, for example, rapidly store and deploy energy from regenerative braking systems.
Urban mobility is another key area. In tomorrow’s intelligent cities, the technology batteries could be ideally suited for autonomous vehicles, whether they are buses or shared cars, which can be recharged in a few seconds when vehicles are at rest. A further benefit could be their use in regulating smart electricity grids, which will have an increased reliance on renewable, more variable energy.
Of course NAWA’s chief operating officer is enthusiastic about the firm’s technology, Pascal Boulanger says: “With our new Ultra Fast Carbon Battery, we have combined the best nanotechnology with the best clean technology. We have a ground-breaking battery that stores more electricity, more rapidly – and it is safer, more reliable and kinder to the environment than current storage systems. What is really exciting is the sheer potential of ultracapacitors.
“The world is becoming increasingly electrified and we see several markets open to NAWA. Products powered solely by Ultra Fast Carbon Batteries, such as powertools and electric bikes, but also our technology combined with lithium-ion. Take an electric or hybrid car, for example. Ultra Fast Carbon Batteries are capable of accelerating that car, reducing the number lithium-ion cells required, reducing the car’s weight and extending its performance and range.
“Then there’s our NAWASHELL technology, which is capable of revolutionising the way we look at energy storage. NAWA Technologies can change the way people relate to electricity: not consuming too much, but consuming better in a more virtuous way – just what you need, whenever you need, wherever you need.”
The technology is promising and Boulanger’s enthusiasm is almost infectious, but there is a lot of development work still to be done before electric vehicles are using NAWA’s Ultra Fast Carbon Batteries, or anybody else’s version thereof.
The life of combustion engine vehicles is coming to an end, it won’t happen quickly, which should give technologies like this develop and mature, but we’re on the path to fully electric vehicles being our main mode of transport. And with new power storage technologies driving 500 miles and refuelling in minutes should continue to be part of daily lives no matter what we’re behind the wheel of.