Lithium ion battery store and release energy by moving electrons from the negative side to the positive side of the battery. When electrons flow through an electrical circuit, they power our electronic devices. It is the same idea as watermill. The watermill uses water flow to spin a wheel that drive a mechanical process such as milling and grinding. Since the electrolyte separates the two lakes, water can only flow is through the water pipeline. The giant hippos cannot go through the water pipeline, so they have to walk past the electrolyte terrain into lake Cathode in valley. When the water from the lake Anode is drained and the last hippos arrive to the lake Cathode, the battery is fully discharged. To recharge the battery, we need the