Envision Energy

Envision is playing a different game than the pure-play startups on this list — it has the balance sheet of a major global energy company to match its ambition. Envision has begun production of sodium-ion cells aimed at grid-scale and backup power applications, backed by substantial project financing that lets it pursue fast-growing markets like AI data center backup power more aggressively than smaller, capital-constrained rivals. The company says its cells offer long cycle life and a wide operating temperature range suited to extreme environments where lithium-ion batteries tend to degrade fastest, and it pairs its hardware with an adaptive energy management software layer — a capability few pure battery makers in this space can match.