Form Energy raised a $70 million Series C to scale its super-long-duration energy storage technology. That investment was first reported by Reuters Friday, without naming the participating investors. It brings Form Energy's total funds raised to around $120 million, a hefty sum for a novel technology that's still a few years away from its first commercial deployment. Lithium-ion batteries dominate nearly all the grid storage that is being installed today, but that technology's cost-effectiveness wanes in applications geared to store energy for many hours or days.