Electric-Car Battery Breakthroughs: Ultimate Guide

26 février 2015

If it wasn't so important for the future of electric cars, it could almost get tiresome: Just how do you improve batteries for longer life, quicker charging and a greater range? Inspired by Popular Mechanics' look at potential electric vehicle and hybrid battery breakthroughs, here is a compilation of our previous battery tech articles into one handy guide. Which of the following will be our batteries of the future?

Aluminum-air

We've all heard--and laughed off--stories of water-powered cars. It just isn't possible on any practical, car-based level. But aluminum-air uses water in a different way. Aluminum is used as the anode in a battery, ambient air (and the oxygen in it) as a cathode, and water molecules. Combined in the battery, they produce hydrated aluminum oxide and energy--and that energy can be used to power a car. The aluminum plates used have high energy density, and companies testing it such as Phinergy say you'd need to refill the car with water every few hundred miles. The air--well, that's all around us.

Improved lithium-ion

Existing lithium-ion technology is among the best battery technology we have for electric cars and hybrids.Compared to other battery types it's relatively energy-dense, charges relatively quickly, is lighter than many other battery types, and it's tried-and-tested. But it isn't perfect, and several research groups are looking for a way to improve on its existing strengths.

Recent advances in nano-technology are proving a popular avenue for lithium-ion. Egg-line nanoparticles of sulfur are one option, improving energy transfer and hugely increasing capacity, while silicon nanoparticles to replace graphite anodes is another.

Egg-like nanoparticles for lithium-ion batteries. [Image: Zhi Wei She et al., Stanford University]

Herbs

It sounds unlikely, but simple herbs could be employed to make batteries greener in future. In a rare look at improving the environmental aspects of batteries rather than increasing their range, researchers at Rice University and the City College of New York have looked at using the herb madder, or purpurin, as a natural cathode for lithium-ion batteries.

Graphene

It's one of the biggest breakthroughs of the 21st century so far, and something we'll be hearing a lot more of whatever industry you look at: graphene.

The "wonder material" is essentially a single-atom-thick lattice of carbon atoms. It's light, incredibly strong for its size, and incredibly electrically conductive. And if those aren't qualities that'd be useful for batteries, we don't know what else is...

Graphene's light-weight benefits are being explored, using graphene rolled into carbon nanotubes and then weaved into an 'Aerographite' material. Graphene 'foam' also has potential--graphene grown on a metal foam to form a three-dimensional structure, both light, flexible and highly conductive.

Graphene paper. Image: Lisa Aliosio

Brine

Another substance aimed at greening batteries, rather than improving range and other factors, is brine that salty water substance. Plenty of it is bubbling out of the ground through the San Andreas fault in California, and it's bringing minerals with it--including lithium. Collecting lithium from the brine is a more ecologically-friendly way of gathering it than digging huge mines, that's for sure.