Lithium comprises only a very small fraction of the mass of Li-ion batteries. The resource constraints are on other elements, like cobalt, used in the electrodes. Lithium could become much more expensive without greatly affecting the economics of Li-ion batteries.
- lithium has scarcity issues which will only get worse with electric vehicles - liquid batteries likewise require some more rarer elements, corrosive enough to require - underground storage (of air pressure, CO2, etc) requires caverns/mines on site - pumped hydro has even tighter site constraints - biofuel/synfuel is decent for mid-to-long term storage, but slow to generate - flywheel has energy density issues
Hydrogen, your main limits are basically steel for tanks, and some rare metals in catalytic amounts.
There hasn't been enough incentive in energy storage deployment to push the scaling up and costs down. But I think we are closest to an "embarrassingly parallel" deployment of hydrogen as energy storage.