Hybrids might have potential - recover energy when braking, charge when idling, use the battery at low speed or instead of idling. Actually makes a sort of sense.
Electric cars are coal powered (unless you are lucky, then they are nuclear or hydroelectric powered...).
But batteries do wear out, and the materials are expensive and toxic. I’d love to see an honest evaluation of battery life and savings vs. cost. I bet they are not available for a reason...
Electric cars probably use the same design as hybrids so energy lost in braking is used to charge the battery packs versus dissipated in heat in the brake pads and brake drums.
However, the original energy is provided by the power plant and whatever means used to spin the turbines.