Save the date: Our 1-year anniversary is coming up. As a thanks to you, we are celebrating with a special subscribers-only event on perhaps the most important challenge facing the industry—building a battery supply chain not reliant on China. Our guest for this September 8 live chat is Bob Galyen, a foremost leader of the U.S. effort to establish a local battery industry, and formerly chief technology officer of China’s Contemporary Amperex Technology Ltd, the world’s largest battery company. Register here for the 3 pm ET call with Bob. Email me directly if you’d like to invite a guest: steve@theinformation.com.

As we all know, batteries degrade steeply over time. So why would anyone agree to hook up their electric vehicle to the grid and let their local utility drain it of power every day? This week, we speak with Jeff Dahn, one of the most important battery inventors of our time, who has an answer: It's the century battery.

For a quarter century, academics and inventors have discussed the idea they call vehicle to grid, in which hundreds, thousands, even tens of thousands of electric vehicles would be plugged into a local electric grid and feed power from their batteries to the utility. Using a bidirectional cord, the same system would charge up the EVs. But this idea—what effectively would add up to a mobile power station—suffered from some major drawbacks: It would be dauntingly expensive, and it was not clear who would pay for it. Perhaps more to the point was this question: Why would any EV owner participate in such a cockup, allowing their battery—a resource with limited life—to be constantly drained and refilled, actions that cause it to degrade?

Jeff Dahn, a professor at Canada’s Dalhousie University and a prominent adviser to Tesla, whom we’ve written about before, has an answer to the second question—that is, why motorists would connect their expensive EVs to power the grid. It’s the century battery, a cell with the capacity to endure multiple daily charging cycles for literally 100 years, adding up to tens of millions of miles on the road. With that kind of robustness, the skeptical motorist wouldn’t care about hooking up their EV to their local utility.