The whole industry is always working on improved batteries. But it's a long road from lab-scale to mass production, and often improvements in one area have downsides in another.

New generations of cells that improve energy density usually start out more expensive than existing chemistries, so they show up at the high end of the market first and work their way down.

If we do get truly improved solid-state batteries available in EVs in the next 5 years, it will likely start at the high end of the market and work its way down over many years to cheaper segments as production capacity ramps up. The base model EVs aren't going to suddenly have their batteries swapped out with ones that are twice as good for the same price.