Occasionally I write a newsletter called The Race to Zero Emissions. (You can sign up here if you’d like.) While reporting our recently published guide to the battery revolution, I asked subscribers to send me their questions about the subject. Some of those questions have been answered in the articles we’ve published so far, but there were some interesting ones that didn’t quite fit, so we decided to answer these individually below.
1. Why so much focus on batteries, and so little on hydrogen fuel cells?
Both technologies have been around for decades, but clearly one is winning. There are currently more than 5 million battery-powered electric cars (BEVs) on the road today but fewer than 10,000 hydrogen fuel-cell cars.
The reason for hydrogen failing to take off is the need for completely new infrastructure. While the world needs more charging stations for electric cars, there is at least an option to plug in BEVs in any electric charger. There are only a handful of places in the world where you can go fill up on hydrogen.
That said, the two technologies share many fundamentals, and as a result, there are researchers currently working on lines of study that could have applications in both batteries and fuel cells. Further, with the costs of renewable energy and water electrolyzers falling, it could still be possible that we will live in a hydrogen-powered future.
2. Which part of the world is leading on battery technology research?
The US is the clear leader in battery research. Through the Department of Energy, the US government has made significant investments in battery research going back decades. In the early days, the research was to gain a competitive edge in space applications. In the 2000s, the focus shifted to electrification of road transport. And now it is focused on electrification of air travel and grid-scale energy storage.
The upshot is that the US has the most number of battery researchers, and thus it also produces the most number of battery startups.
That said, as MIT professor and battery entrepreneur Yet-Ming Chiang told me, the US doesn’t yet have the right support to help batteries go from pilot to industrial scale. As a result, a good few startups in the US have ended up scaling up in China or being purchased by Chinese companies when their US efforts to scale up failed.
3. Is the battery-management system becoming more important than the battery?
A battery management system is crucial to applications of lithium-ion batteries in everything from phones to electric cars. For example, lithium-ion batteries in cars heat up a lot when charging or discharging. Without some system to monitor and manage heat, the materials inside can become damaged and the battery will have a shorter life. Another example: Most electric-car battery packs are made up of hundreds of small batteries inside it, and when charging or discharging, the system has to maintain a proper balance among all these individual units. Without a battery management system, there is a risk of overcharging one of the many units, causing it to fail or even catch fire.
The ultimate limits on the battery come from fundamental physics and chemistry, which are more difficult to overcome than problems of management-system software. So batteries are still more important than the battery management system.
4. Are solid-state batteries going to be practical—and commercially available—for cars in the next few years?
It seems so. Venkat Viswanathan, a professor at Carnegie Mellon University and an advisor to QuantumScape, one of the hottest solid-state battery startups, certainly thinks so. Typically, new battery materials take 15 years to go from lab to commercial scale. QuantumScape was founded in 2010.
For context, solid-state batteries use a solid electrolyte material instead of the typical liquid electrolyte. The job of the electrolyte is to shuttle ions between the electrodes, as the battery charges and discharges. Using solid electrolytes will open up the possibility of using new types of anode, such as lithium metal, which store a lot more energy than today’s graphite anode.
The difficulty is that, so far, liquids tend to be better at doing the job than solids. But companies like QuantumScape, Blue Current, and Toyota are trying to solve the problem.
5. Are there any home-sized flow batteries in a reasonable price range?
Yes. There’s a company in Australia called RedFlow and another in Germany called Voltstorage that offer flow batteries for homes. Whether you consider their pricing reasonable price will depend on where you live and what you pay for the electricity you consume.
For context, “flow batteries” are unusual type of batteries. Instead of packing the energy in a small solid case, like most batteries, flow batteries store energy in large amounts of liquids held in vats attached to pumps. The most common use for flow batteries is in industrial application. That’s because scaling up the battery requires large vats and pumps, and thus tends to be cheaper to use for larger-scale storage. RedFlow and Voltstorage’s products appear to be about the size of a typical refrigerator; neither company publishes prices on their websites.
6. What are the plans to reuse and recycle battery metals to minimize constant extraction of metals?
I answered this question at length in the opening article of Quartz’s battery field guide, which lays out the state of the industry. State of Play article. The short answer is that, so far, economics of batteries haven’t supported the need to recycle or reuse. That’s starting to change as the number of electric cars sold keeps increasing.
Reuse: Companies like Nissan, Renault, and Audi are putting their electric-car batteries to second use in energy storage or in other electric vehicles. But such applications are yet to go beyond pilot tests.
Recycle: There’s a lot more happening here. In 2018, Audi and Umicore showed that 95% of the valuable materials in lithium-ion batteries can be recovered from recycling. The Chinese government has also laid down stricter recycling regulations, which have encouraged battery makers to invest hundreds of millions of dollars in setting up recycling plants.
In short, on both fronts, we’ll see a lot more happening in the next few years.