Batteries that are cost effective largely solve the intermittent renewable problem. Lithium batteries aren’t even suited to anything more than very short term storage of minutes to a few hours, lithium was developed for energy and power density, able to sustain vibration and impacts without damage (such as being dropped without dents), and the cost can be relatively high as these are mobile device requirements like for laptops, power tools, and EV.
Grid storage is almost diametrically opposed. Energy and power density almost don’t matter at all, if a lithium battery needs to be a ten foot cube, something 100 times less dense mass or power wise is only 46 feet. They can be extremely fragile, and not work under vibration or movement. Low cycle cost lifetime is extremely important. It’s also much more important to have a high efficiency of discharge energy to charge energy. So really lithiums only make sense in niche cases and it’s why pumped hydro is still the vast majority of stored kWh.