GM's Lithium-Free Bet Is a Grid Battery: Peak Energy Raises $108 Million for a 4 GWh Sodium-Ion Plant

Peak Energy, a sodium-ion battery maker, closed an oversubscribed $108 million Series B led by GM Ventures, according to an Electrek update dated October 23. The cells GM is developing with it contain no lithium, but they are not for vehicles; they are for grid-scale stationary storage, according to Electrek.

The photograph shows a Tesvolt lithium-based storage system in Switzerland, used here only to show the container format of stationary storage. It is not a Peak or GM product.

What GM and Peak are building

GM and Peak announced the partnership on June 10, 2026. GM develops the sodium-ion cell in its Michigan battery labs and keeps exclusive manufacturing rights, while Peak builds the cell into its own storage systems, per Electrek. GM Ventures made a strategic investment in Peak, and LG Technology Ventures is among the other investors in the Series B.

Kurt Kelty, GM's vice president of battery and sustainability, said: "At GM, we know that the application should determine the battery." Electrek adds that sodium-ion's lower energy density makes it unsuitable for vehicles.

The denominator: 4 GWh a year against 6 GWh of commitments

Peak chose Sacramento, California, for a plant of up to 4 GWh a year, according to EnergyTech's July report. The facility is 183,000 square feet in Metro Air Park, with shipments planned for the first quarter of 2027. Peak reports 6 GWh of customer commitments, with agreements in place with Jupiter Power, Energy Vault and RWE Americas.

Those two figures do not match. At 4 GWh a year, a full-rate plant needs a year and a half to fill 6 GWh, and the plant has not started production.

The plant's capital investment is $71 million, which works out to roughly $17.75 million per GWh of annual capacity. It also received a $10.5 million CalCompetes tax credit, awarded in May. Peak says the Series B proceeds will go to U.S. manufacturing, to filling more than $1 billion in existing customer orders and to the data-center market. If the $1 billion and the 6 GWh describe the same orders, which neither source says, that implies about $167 per kWh. Treat that as an arithmetic check, not a price.

1. Peak Energy plant, per year4 GWh
2. Peak Energy commitments6 GWh
3. Alsym Energy, ESS Tech partnership8.5 GWh
4. Alsym Energy, ERITY agreement9 GWh

Source: EnergyTech, July 10, 2026, accessed 2026-10-23

The bars compare different things: plant capacity, commitments and agreements. They show scale, not output.

Peak's claims, and what is unverified

Peak says its passively cooled platform removes the active cooling equipment conventional lithium iron phosphate (LFP) storage needs. The company claims it cuts storage cost by 20% against conventional systems and delivers more than 99% uptime, per Electrek. Both are company claims; neither source names an independent test.

Peak also estimates that switching conventional LFP storage to its design could cut annual U.S. battery-storage energy waste by up to 2 terawatt-hours. The figure is Peak's.

EnergyTech's July report says sodium-ion is under 1% of global EV and storage battery production and costs more than lithium-ion per equivalent capacity. That sits awkwardly beside a 20% cost-reduction claim, and neither source breaks down where the saving would come from.

Cars and data centers

For the vehicle side of battery chemistry, see the Terminal's piece on the VW ID. Cross Trend and its two conflicting charging times. Sodium-ion is not in that conversation, because Electrek says its energy density rules out vehicles.

Peak says data centers are its next market. The compute demand behind that is covered in the piece on Amazon's Trainium software.

What to watch

The test is Q1 2027, when Peak says shipments from Sacramento begin. A first delivery with a GWh figure attached would settle whether the 4 GWh plant can serve 6 GWh of commitments on schedule.