General Motors has plans to operate four battery plants, with one in Lordstown, Ohio already pumping out cells. With the ability to make its own batteries comes the potential for custom configurations and form factors, something the company is considering taking to the extreme. A recent patent from GM shows batteries not shaped like rectangles or cylinders, but Tetris-like blocks meant to accommodate more efficient cooling channels.
The document is currently just an application, but it was published very recently in late February, with a recent file date as well. All of this seems to indicate it's a new idea out of the automaker that it may have wanted to protect quickly. It begins by saying how battery cells are currently cooled, at least in GM's case. In cars like the Hummer EV, we know this is achieved on a module-by-module basis with a cooling plate at the bottom of the cells. In this patent, GM claims this method can lead to uneven cooling, which leads to premature battery degradation. As a side note, other companies use other cooling methods to combat this phenomenon.
GM's idea is to make the cells in a rough "L" or "C" shape so that two cells combined will leave one or more tunnels between the cells where a cooling channel can be added. GM even has some unusual diagonal shapes in there.
Gallery: GM Tetris Battery Cells Patent
I'm not aware of any other battery cell, at least in automotive use, that is shaped anything like this. I have personally only ever seen rectangular prisms or cylinders. There might be considerable manufacturing challenges associated with making these strange cells, though it's tough to tell going only by this application.
To that end, the company suggests other possible configurations using rectangular prismatic cells but achieving a similar effect. Two of the cells in a proposed four-cell group would be shorter and fatter, while the other pair would be longer and skinnier. This would allow for a rectangular or H-shaped cooling channel. Longer and skinnier cells like that are less common, but there's one China-based company, Topband, that makes somewhat similar long slender lithium iron-phosphate cells.
In any case, GM's idea is an unusual one that may have some merit, but it's unclear if developing an entirely new cell format in the name of cooling would be an effective approach to improving electric vehicles. If the company patented it, it's likely worth exploring, at least conceptually.
