US firm Form Energy has secured $405m (£310m) from investors to progress its battery technology that is longer lasting than lithium-ion.

Most modern tech, including smartphones, electric vehicles (EVs) and grid-scale storage, uses lithium-ion batteries. But the technology is prone to degrading over time, particularly if frequently charged and discharged in full cycles. Manufacturing them also requires rare and expensive materials such as lithium and cobalt, leading to environmental concerns around mining and disposal.

Instead, Form uses an iron-air battery system that is effectively based on a reversible rusting process capable of discharging energy for around 100 continuous hours. While they are too heavy to be used in consumer gadgets or EVs, they are ideal for use in grid-scale storage where weight isn’t a major concern, but longevity is.

Form Energy CEO Mateo Jaramillo said: “Form is at an exciting juncture as we gear up to fulfil our mission of deploying multi-day energy storage solutions...