Contemporary Amperex Technology Co Ltd signed a three-year deal to supply 60 gigawatt-hours of sodium-ion batteries to energy storage firm Hithium Energy Storage Technology Co Ltd on Monday, marking what the companies said is the world's largest order of its kind.

The agreement, signed in Ningde, in eastern China's Fujian province, positions Hithium as CATL's first strategic partner in sodium-ion batteries for energy storage, the companies said in a joint statement.

Under the deal, the two sides will collaborate across research and development, product deployment, and project implementation, as CATL pushes to commercialize sodium-ion technology at scale.

The partnership signals that CATL has overcome key bottlenecks across the sodium-ion battery production chain, enabling large-scale manufacturing and delivery, according to the statement.

Sodium-ion batteries are widely seen as a lower-cost alternative to lithium-ion batteries, particularly suited for grid-scale energy storage, though they typically offer lower energy density.

The companies said the deal could usher in a new phase of rapid industrial expansion for sodium-ion batteries globally, as China's battery giants race to diversify beyond lithium and secure leadership in next-generation energy storage technologies.