GM Bets on Sodium-Ion Batteries to Undercut Lithium on Grid Storage

Colorado startup Peak Energy is trying to make sodium-ion batteries viable for U.S. grid storage after a string of Western failures, including Natron Energy and Bedrock Materials, both of which folded last year. Its edge over those predecessors is a partnership with General Motors, which — like Tesla and other automakers facing weak EV demand — is pivoting toward stationary storage to keep its battery plants running. Peak plans a $71 million factory near Sacramento with 4 GWh of annual capacity, slated to open in 2027. GM’s battery chief Kurt Kelty, a Tesla alum, says Peak’s cells have outlasted rivals in 55°C testing and hit 96 percent round-trip efficiency, a few points better than the incumbent lithium-iron phosphate (LFP) chemistry.

The core pitch is not raw energy density, where sodium-ion still trails LFP, but total lifetime cost. Peak claims its cells tolerate roughly double LFP’s operating temperature, enabling a passively cooled system with no fluid loops, fans, or pumps — cheaper to run and well-suited to hot, remote desert sites near solar farms and data centers. The company projects 20-year, 20,000-cycle life retaining 80 percent capacity, and a 20 percent lower lifetime cost than LFP despite higher per-cell prices today, with cell-level parity expected around 2028. Crucially, Peak uses sodium iron pyrophosphate (NFPP) cathodes, structurally similar to LFP and now an emerging industry standard also adopted by CATL, making the cells largely “drop-in” for existing plants like GM’s.

The unresolved catch is the supply chain. While sodium is roughly 1,000 times more abundant than lithium and the U.S. holds vast trona deposits in Wyoming, China dominates both raw-material processing and cell production. Peak currently sources its commercial cells from Chinese suppliers, and analysts at Benchmark Mineral Intelligence project sodium-ion will account for under 1 percent of new U.S. storage this year and under 4 percent by 2030 — meaningful potential, but a long climb before the domestic supply chain catches up to the abundant raw material.