How did batteries evolve from stacked discs to powering electric cars?

The answer

In 1800, Alessandro Volta stacked alternating zinc and copper discs separated by brine-soaked cardboard to create the first true battery - inspired by Luigi Galvani's observation that frog legs twitched when touched by different metals. Lead-acid batteries (1859) powered early electric cars, and nickel-cadmium cells dominated for decades. The real revolution came with lithium-ion batteries, commercialized by Sony in 1991. Lithium-ion cells store three times the energy of NiCd at a third of the weight, enabling everything from smartphones to Tesla vehicles.