Most attempts to improve lithium-ion batteries involve changes in the chemistry or components of a cell. But you can also work wonders on the larger scale of the battery pack—the array of cells that power big machines, like electric cars.
That’s the tack taken by Cadenza Innovation, a Connecticut firm started up by Christina Lampe-Onnerud, a Swedish battery maven we profiled back when electric automobiles were just getting going (“The Lady and the Li-ion,” March 2008). And because the strategy, which she calls a supercell architecture, allows for the packaging of different cell shapes and sizes, it means serving existing battery companies rather than supplanting them.
She declines to reveal which manufacturers Cadenza is negotiating with.
Lampe-Onnerud’s earlier initiatives centered on the cell itself, but that required her to play the sharp-elbowed game of mass manufacturing. That game is far harder to get into now that megacorporations have started building battery gigafactories.
“We simplify the architecture and manufacture of the batteries, eliminating quite a few parts,” she says. “That means there are more energy-carrying components and fewer surrounding components.” You can get from 30 to 100 percent more watt-hours per kilogram of battery pack, depending on the kind of cell being used and the number of cells in the array.
Exploded view of the supercell architectureImage: Cadenza Innovation
Besides increasing energy density, the idea also cuts cost. One electrical connector can yoke together 20 or 30 cells, for instance. And, by offering a way to keep the familiar “jelly roll” cylindrical cells separate from one another, in a heat-resistance plastic frame resembling an egg crate, Cadenza makes it safer to be around all that close-packed energy.
This heat-resistant, egg-crate structure separates the “jelly roll’’ form of lithium-ion cellsPhoto: Cadenza Innovation
Other safety devices enter the mix as well, like a vent, a pressure dome, and a mechanical means of connecting and disconnecting cells. Of course, the tradeoff of energy density and safety goes in both directions: A customer can choose to pack even more cells into a battery while maintaining existing safety standards.
“You can say we’re packaging 20 years’ worth of best practice into a Lego block,” she laughs. “And it’s coming out when one of the best performaners, Samsung, overstepped what it should have done with its Galaxy phone.”