The widespread use of electricity to power vehicles depends on making the batteries less expensive, lighter, and perhaps more durable. For the past decade, the big push in battery technology has been toward improvements in materials that increase the electrical capacity of the battery without adding too much to the manufacturing costs or weight or losing anything in reliability. The improvements, though, haven’t been coming in as fast as had been hoped, and now some researchers are looking in other directions. One thought that is showing some promise is the idea of reducing the time to recharge a battery. If the battery recharges faster, then for many applications including cars, the capacity of the battery becomes less critical.
A shorter recharge time fundamentally means a smaller cell size. Cells are the chemical components inside a battery that store electricity, with at least three layers of different materials chosen for their contrasting electrical properties. A simple battery may contain only cell, a lead-acid car battery, six cells. What if you made a battery with millions of tiny cells? With smaller cells, the distance from the middle of the cell to the edge is smaller, and that should make it possible for the battery to charge faster.
Prototypes prove this works in practice, but it is an immense manufacturing challenge to make so many small cells quickly, so that the manufacturing costs are low enough to be practical. The answer might be found in recent advances in nanotechnology. Nanotechnology creates a range of small devices by getting materials to go together consistently on a small scale.
Wendy Koch writing in National Geographic explores the nanotech side of batteries in a new story: