GM Leads $108 Million Round for Sodium-Ion Startup Peak Energy

General Motors has led a $108 million Series B round for Peak Energy, betting that sodium-ion batteries can undercut lithium-ion for grid-scale storage. The money will help ramp up manufacturing at the energy-storage startup's California plant, according to a Wednesday announcement first reported by Bloomberg.

The number that explains the timing: sodium-ion demand is forecast to reach 257 gigawatt-hours by 2035, up from just over 1 gigawatt-hour in 2025, according to BloombergNEF. By then, the technology could account for almost 10% of stationary storage.

Peak says its sodium-ion cells tolerate higher operating temperatures than lithium-ion cells, which offers cost and safety advantages for data centers, grids and independent power producers. It's one of several startups racing to scale manufacturing for grid-scale storage systems.

Why did GM Ventures write the check?

GM Ventures President Kevin McCabe laid out the logic in a statement Wednesday. The firm invested, he said, "because we believe it has significant potential in the energy-storage market as a safe, cost-effective solution using abundant, domestically sourced materials."

The deal deepens an existing relationship. In June, the two companies announced a partnership to advance sodium-ion technology in the US. GM is developing sodium-ion cells at its Michigan battery labs, and Peak plans to use those cells in its energy-storage systems later on.

In plain terms: GM supplies the cell chemistry, Peak builds the storage business around it.

How big is Peak's order book?

Peak reports roughly $1.1 billion in customer orders. Two contracts account for most of it:

• A 4.75 gigawatt-hour agreement with Jupiter Power
• A 1.5 gigawatt-hour deal with Energy Vault

The company is already shipping small volumes from a pilot line in San Francisco. CEO and co-founder Landon Mossburg said Peak expects to complete its first commercial facility in the first quarter, with battery systems rolling off the line shortly after that.

Mossburg framed the GM partnership in supply-chain terms. "You just want to catalyze this supply chain as much as possible," he said. "It's already catalyzed in China."

Can sodium-ion actually compete on cost?

Not yet. The sodium-ion cell market remains far from mature, and the cells still cost more than lithium-ion alternatives. Both technologies also face the same trade pressures, with the bulk of manufacturing concentrated in China and other parts of Asia.

Peak investor Greg Reichow, a partner at Eclipse Capital, argues the cost gap closes over time. Lithium-ion batteries "are very cheap right now because they're at a very high scale," he said. "When you look at fundamental materials that are in sodium-ion and the actual costs that it takes to transform those materials, it will ultimately be lower cost."

Reichow points to two structural advantages: the raw materials for sodium-ion cells are readily available in the US, and costs should fall as the technology matures. That makes sodium-ion an easier and cheaper path to domestic manufacturing than rebuilding a lithium-ion supply chain from scratch.

The $108 million question — literally — is whether Peak can move from a San Francisco pilot line to commercial volumes fast enough to convert $1.1 billion in orders into revenue before cheaper Chinese sodium-ion cells flood the market.