A battery is just a tepid chemical reaction that we can easily reverse, which is why we accept the poor energy density. If we could find a dense fuel that didn’

A battery is just a tepid chemical reaction that we can easily reverse, which is why we accept the poor energy density. If we could find a dense fuel that didn’t throw off a lot of carbon dioxide or methane, synthesizing that would probably be better. If only storing hydrogen weren’t such a problem …