Building a better battery requires dealing with problems in materials science, chemistry and manufacturing. We regularly cover the work that is going on in the previous two categories, but we get a fair number of complaints about our inability to deal with the third: to find out how businesses manage to take solutions for science and to convert into usable products. So it was exciting to see that a company called StoreDot, which allows the development of a battery for five minutes of charging electric vehicles, was apparently willing to talk to the press.
Unfortunately, the response to our queries has become a little less than we hoped. “Thank you for your interest,” was the reply, “we are still in pure R & D mode and can not share any information or answer questions at this time.” The company apparently gave The Guardian an exclusive option and did not speak to anyone else.
Undoubtedly, we have since retrieved every bit of information we could get from StoreDot’s website to find out approximately what they do, and we have gone backwards from there to go looking for research we have previously discussed related. Following is an attempt to put together a picture of the technology and the challenges that a business must face in order to take research concepts and make products out of them.
The need for speed
To some extent, StoreDot uses ideas that have been floating around in research labs and startups for years, but it takes a bit of risk by using these ideas in a way that differs from their apparent promise. The bet that StoreDot makes is that it is not the absolute charging range of an electric vehicle that matters; this is how fast you can expand the range. Although it uses research on technologies that allow greater capacity in lithium-ion batteries, it turns around and increases the capacity to speed up charging.
In other words, the bet is that people would rather add 300 km to the range of their car within five minutes than have a car with a 600 km range that takes an hour to fully charge.
What are the implications of betting at the hardware level? They are mostly dictated by heat management. As anyone knows what puts a laptop with a charging charge in the lap, it knows that charging a battery produces a lot of heat. Loading it faster yields even more. To handle this heat, StoreDot essentially produces a diffuse battery with plenty of space between individual cells, as you can see at the four-minute point of this video (embedded below). The cells have significant gaps between them, and the battery housing has holes that allow airflow between them. It is charged on a stand with fans that force air through the battery to keep the heat under control.
Anyone can do this with the existing battery technology, but there is a very clear cost: a much lower energy density, which means that a battery must be much larger to hold the same amount of charge. StoreDot compensates by working on technology that allows a much higher charge density, which compensates for the lower density of materials. Finally, the battery should contain similar amounts of charge per volume as existing batteries, although there is less battery material.