If you really want to play with this sort of thing, look into aluminum-air batteries. Your aluminum cans might be worth more than the deposit. Aluminum is refined electrically from aluminum oxide because the latter has the highest heat-of-formation of any compound, making purely chemical extraction energetically infeasable. You can get much of that juice back out - at quite high power density.
Caution: Aluminum is WAY toxic - including neruotoxic. Use extreme care when smelting your used cans into cast electrodes and when discarding the bauxite cleaned out of the batteries when you install new electrodes. Especially don't get exposed to fumes and be sure to carefully dispose of battery leftovers as toxic waste.
(Your body can't excrete Aluminum. Instead it has an extreme barrier against absorption, attempts to clear the little that gets past the barrier by laying it down in bone, and once that's full your brain is toast. Look up "dialysis disease". Symptoms just like Alzheimers. Patients got it from early artificial kidneys, limiting how long they could be on dialysis. At first they thought it was from something a natural kidney cleared that wasn't getting removed by the artificial versions. Eventually the docs figured out it was Aluminum poisoning - from the few atoms released by the water bath container and diffusing directly into the blood - and switched to stainless.)
