GM is adding a manganese battery at Spring Hill

General Motors is not putting the cheap iron-phosphate battery into its cars. On Monday its joint venture with LG Energy Solution said the cell plant at Spring Hill, Tennessee, will be altered to make a different one: lithium manganese-rich, in a flat prismatic can, for electric vehicles that GM has not named.

The building work starts later this year and is supposed to be finished in 2028. Ultium Cells has not said when the first of those cells will come off the line. It says the plant should be the first in the world to make this kind of cell in volume. Take that as the company’s claim. The part you can use is the place, the chemistry, and the date on the building.

2028

When the building work is due to finish. No date for the first cell

500

Jobs on top of the 1,200 people already there

33%

The energy-density gain GM claims against iron phosphate, at a similar cost

$1bn

Spending on this line, the storage cells and the building, by 2030. Not a new cheque

Two chemistries, one roof

Spring Hill is already making cells. Since June it has been turning out lithium iron phosphate for LG Energy Solution Vertech, which sells batteries that sit on the grid, not batteries that go in a pickup. So the iron chemistry is in the building. It is just not the one GM has chosen for the car.

The manganese cell is meant to sit between the two things a carmaker usually has to choose. High-nickel cells go further and cost more. Iron phosphate is cheaper and heavier for the energy you get. Kurt Kelty, who runs battery work at GM, said high-nickel will stay the long-range option. The manganese cell, he said, is there to get past today’s cheaper chemistries: lower cost, and better performance than those cheaper cells. GM puts the gap at about a third more energy in the same weight as iron phosphate, for about the same money. That is a design target. It is not a pack you can order.

The shape matters as much as the powder. Prismatic means a flat, hard can, stacked, rather than the pouches Ultium has used. The company says Spring Hill will be able to run more than one chemistry and more than one shape. High-nickel, iron phosphate, and now manganese. Pouch and prismatic. A buyer of cooling plates, busbars or module frames should ask which of those is actually on the line they are quoting, because they do not share a drawing.

The money, read slowly

Ultium says the combined spending on the two programmes, the storage cells and the manganese cells, plus the work on the building, will reach $1 billion by 2030. That is not the same sentence as “GM has just written a cheque for a billion.” Some of it is the iron-phosphate line that started in June. Some of it is still to be spent. None of it comes with a breakdown.

The jobs are clearer. Five hundred more people, on a workforce of 1,200. If those 1,200 are still there when the line is finished, the plant would have 1,700. The company has not said they all will be. In March GM talked about bringing back about 700 laid-off workers at the site to make batteries that do not go in vehicles. That was a different announcement, about the storage work, and it should not be added to Monday’s 500.

What the 33% does not mean

A third more energy density is a cell claim, set against iron phosphate. It is not a promise that the car will go a third further. Range also depends on how the pack is cooled, how heavy the vehicle is, and how much of the cell’s energy the car will actually use. GM has not published a pack, a vehicle, or a mile figure for this line. If a slide already has one, it did not come from Monday’s announcement.

The can is the other change, and it is the one a supplier feels first. A prismatic cell is a rigid box. A pouch is a soft rectangle that has to be squeezed and protected. The frames, the cooling plate, the vent path and the busbar are different drawings. Ultium already makes both shapes. Quoting Spring Hill as if it were the pouch plant will price the wrong part.

Kelty was also careful about where this sits. High-nickel stays the one for the customers who want the furthest car. The manganese cell is the attempt to undercut the cheaper chemistries without giving all of that range away. He did not say iron phosphate is finished at GM. The iron cells at Spring Hill carry on, for the storage customer that started taking them in June.

What you can put on a plan

If you sell into a GM pack, or you make the cathode powder, Spring Hill is now a named manganese line with a 2028 date on the building and no date on the car. If a programme brief still has Spring Hill down as an iron-phosphate car plant, change it. The iron cells there are for storage. The cells GM wants in a vehicle are the manganese ones, and they are not in production.

It is a different bet from the one Volkswagen has just been making in Spain, where the talk is of iron phosphate for the car. GM is keeping the expensive chemistry for range and trying a manganese one for the rest. Both are still plans. Neither has a part number. The difference, this week, is that the American plan has a building, a partner, and a year on the construction.