Matter cannot be created nor destroyed. And elemental conversion is a big deal - usually involving nuclear fission or fusion. Batteries do become depleted but

Matter cannot be created nor destroyed. And elemental conversion is a big deal - usually involving nuclear fission or fusion. Batteries do become depleted but the lithium never disappears, I guess simply put a reverse potential is no longer able to reverse the battery equation back to the energy storing state. Presumably because there is some third reservoir state that a potential cannot reverse (without delving into the chemistry). Don't be mistaken into thinking that because a charger cannot reverse the battery reaction that the lithium itself is gone, or that there does not exist some completely unrelated process that can recover the lithium - separate from the immediate battery ecosystem