Could an electric vehicle go 550 kilometres on a single charge? Nissan came to the Geneva Motor Show last month with a new battery technology that significantly increases energy density and performance. The technology will be available in an updated version of the Japanese automaker’s Leaf and e-NV200 models. At the show, Gareth Dunsmore, European General Manager for electric vehicles at Nissan, noted that battery technology is seeing rapid development in two areas — quick chargers with top-up charging ability, and batteries that literally go the distance.
The Advanced and Post Lithium-ion Batteries 2016-2026 report, released by IDTechEx in October 2015, asserts lithium-ion battery tech is the best we have ever seen. It has increased in energy density by 5 per cent every year, and decreased in cost by 8 per cent.
However, the report adds that “A new generation of battery technologies will be necessary in order to address the existing and future challenges of the increasingly complex energy systems our society will require.” Lithium-ion and lead acid batteries will be in charge for the next decade, but newer technologies have the potential to grab around 10 per cent of the battery market. We look at five emerging technologies below
It’s been called the ultimate battery tech and boasts of an energy density ten times that of lithium-ion, apart from being 90 per cent more efficient. University of Cambridge scientists have assembled a lithium-air battery and recharged it over 2,000 times without blowing things up.
They note that such a high energy density would be comparable to that of gasoline, and also allow for car batteries that are one fifth the cost and weight of current options — and still pack in enough capacity to take you more than 600km on a charge.
The underlying tech is similar to lithium-ion, but lithium is a rare element, expensive, and subject to political instability. In contrast, sodium is virtually limitless. But as the Institute of Electrical and Electronics Engineers’ Spectrum magazine notes, finding suitable electrodes has been a challenge.
This may have been overcome though. Last year, French scientists demoed a prototype with a special composition for the negative electrode, but the tech is still less efficient than lithium-ion.
How about a set-up that charges in 16 seconds and can be recharged over 10,000 times? In home electronics, capacitors charge rapidly, but also discharge in seconds. Supercapacitors made of graphene retain the former trait, but release the charge gradually, like a battery. However, a downside is that energy density is on par with existing lithium-ion tech.
Lithium-sulphur batteries can hold double the energy of lithium-ion, and can be produced cheaply. But a major drawback is that they can’t hold a charge for long.
Science Daily reports the Pacific Northwest National Laboratory found that when LiTFSI (a salt) is packed in the liquid, the battery can hold most of its charge for more than 200 uses. “Drivers don’t want to be stranded between charging stations, and this concern can factor into their decision to buy lower emission vehicles. The results of this study add another important page to the design guide for high-energy lithium-sulphur batteries.”
Solid state batteries
Bosch, Toyota and Volkswagen are working on solid-state batteries that will double the range of electric vehicles at half the cost.
The tech dispenses with liquid electrolytes to make cars non-flammable. It can operate in temperatures from minus 30 to 100 degrees Celsius and vehicles don’t need a cooling system.