Lithium-Sulfur:

https://oxisenergy.com/products/

The catch here is that they don't last that many cycles and the figure per unit volume is not amazing.

Great for aircraft though.

That page says they're only hoping for availability soon.

I've been following this company for years. They used to be overly optimistic, but got a reality check along the way and now are more careful in their statements.

Anyway 400Wh/kg are available as samples - that's not far away from 500Wh/kg.