It's easy to charge cells in parallel. The problem is keeping the battery from catching on fire when you do that.
Good point. Their are 15 to 20 batteries claiming they have the solution and taking in VC money or are internally funded. Of this group many are in the "solid state battery" space, were the electrolyte is supplanted with a permeable membrane. With the membrane, they are also claiming no the risk of fire from "dentryting" (Li creating mountain ranges under a microscope and causing the fire problem ) they can go to pure Lithium vs the Li-Ion mixture which I believe is diluted w/ graphite. With the pure Li, they can then up the energy densities....