A year ago, Redwood Materials didn’t have an energy storage business. Now, it is the fastest-growing unit within the battery recycling and materials startup — a reflection of an AI data center building boom.

The evidence of that growth, the company says, can be found at its R&D lab in San Francisco, which has expanded four-fold into a 55,000-square-foot facility and now employs nearly 100 people. Those are small figures compared to Redwood’s total workforce of 1,200 people and its sprawling campus at its Carson City, Nevada headquarters and another facility near Reno.