Sodium-ion batteries are ready for world domination

A new type of home battery is moving fast toward the market: sodium-ion. Most home batteries today use lithium, but sodium is cheaper, more abundant, and not controlled by a single country's supply chain. Sodium batteries also handle extreme heat and cold well (companies cite a range of -40°F to 140°F without losing performance), so they don't need the fans or cooling systems lithium batteries often require. That means fewer moving parts, less noise, and less maintenance.

For homeowners, the one to watch is Unigrid's Na+Casa, a 9.25-kWh sodium battery designed for houses. It's rated for more than 10,000 charge cycles at full depth of discharge, meaning it can be run down completely that many times before wearing out. Its size is limited by current fire-safety rules for sodium batteries, which cap them below the 15-kWh lithium units already sold for homes. Unigrid is now partnering with a manufacturer called Syntropic Power to build these batteries in the U.S.

Sodium batteries aren't cheaper than lithium yet, but the company developing this one expects costs to drop sharply over the next five to ten years, since sodium itself is inexpensive and most of the cost is in manufacturing, which should improve with scale. Grid-scale sodium batteries from other companies, including ESS and Peak Energy, are also set to launch in 2027, which could speed up the technology's spread. None of this is available to buy yet, but it points to a lower-cost, lower-maintenance alternative to today's home batteries within a few years.