In a carefully managed release of data, QuantumScape announced that its lithium-metal battery would take a car 240,000 miles and recharge in 15 minutes. The data show the cells working comparatively well in cold temperatures.

I wrote in The Mobilist yesterday about how the San Jose-based battery company is playing down what it must do next: Scale up from a single-layer cell to 100 layers, make its separator without defects, and do so fast and continuously. But when discussing his own work, Elon Musk says scaling up is 99% of the effort. The prototype is just 1%.