GM could add alternative battery chemistry to slash costs

General Motors could add different battery chemistries and form factors that move beyond its plans with LG Energy Solution as the automaker launches a line of affordable electric vehicles, analysts said.

GM has announced three U.S. battery plants with LG Energy Solution under its joint venture, Ultium Cells. The companies have said for months that they would add a fourth U.S. plant but have not reached an agreement.

The automaker plans to offer a line of EVs priced below $30,000. But that would force it to move away from the high-cost lithium nickel cobalt manganese chemistry, or NCM, used in the Ultium design. A different chemistry, such as the less expensive lithium iron phosphate, or LFP, would get GM closer to its price target but could require an additional battery partner, analysts said.

"If you're going to build a low-cost EV, I don't see how you can do it with an NCM battery," said Conrad Layson, senior alternative propulsion analyst at AutoForecast Solutions. "I think you have to use an LFP. That means shorter range, less performance than many drivers anticipate."

GM spokesperson Phil Lienert declined to discuss future technology plans but touted the flexibility of the Ultium platform. It can accommodate "a range of cell form factors and battery chemistries," he said.

The platform is chemistry-agnostic and can take pouch, cylindrical or prismatic cells, GM CEO Mary Barra told analysts last month. She said the automaker is considering the use of all three.

"We're looking really at performance," she said. "With the way that you configure the packs within Ultium, the difference of the cells [has to do] with performance and how do we get the max benefit."

Discussions about a fourth Ultium plant are ongoing, LG Energy Solution said in a statement to Automotive News.

GM executives have said the automaker would build an EV for customers in every price tier, with some priced below $30,000.

Sam Abuelsamid, principal analyst with Guidehouse Insights, expects that GM will add plants to build lithium iron phosphate batteries to power lower-cost mass-market EVs and commercial EVs.

Those cells typically cost about 30 percent less than nickel cobalt manganese cells, but the gap may have widened on higher nickel prices, he said.

If GM were to build an EV with a 100-kilowatt-hour battery, the cost of doing so with an NCM battery would be about $15,000 at today's material prices, according to Abuelsamid. Batteries for that same model using LFP chemistry would be closer to $10,000, based on current pricing. The $5,000 savings would be a significant factor in GM's ability to sell the car at a lower price.

The driving range of EVs with LFP batteries is 30 to 35 percent shorter than for vehicles with NCM batteries, he said. But that still fits the needs of many commercial vehicles, which travel repeated and predetermined routes. And it is suitable for most everyday work commutes, Abuelsamid said.

GM has touted the use of stackable pouch cells for its Ultium battery architecture. The modular design allows GM to use the same platform with any vehicle type — from cars to commercial vans and full-size pickups.

Pouch and prismatic cells can be stacked with minimal space between cells because of their rectangular shape. They fill the volume of the entire battery pack or module, Abuelsamid said. Cylindrical cells can't be packed as densely. The space between them when installed in a rectangular module results in lower energy density, he said.
GM could also consider cell-to-pack designs with LFP batteries, which would increase the share of active material at a lower cost, he said.

"It's way cheaper than nickel chemistries. Iron and phosphorus are readily available everywhere," Abuelsamid said. "You're not going to have any supply chain issues with iron and phosphorus. And it's also very durable."

Regardless of cell form and battery chemistry, modular architectures are easier to service than cell-to-pack structures, but the modules take up more space. Typically, only 30 to 40 percent of the pack volume in modular architectures is active cathode and anode material, but the active material can double with a cell-to-pack architecture, Abuelsamid said.
Lindsay VanHulle contributed to this report.