The Function of Rechargeable Batteries
Rechargeable batteries are one of the most revolutionary technologies in history. Batteries have two sides, an anode (negative during discharge) and cathode (positive during discharge). Electrons move due to an electric field created by a voltage difference, and are released from the anode during discharge. The anode is usually made up of graphite, while cathodes are usually made up of lithium metal oxide. Lithium is used for these batteries because of how easy it looses it valence electron and forms stable lithium ions. Electrons are held in the anode material due to atomic structure and electromagnetic attraction. This makes the anode negatively charged.
How They Discharge
Lithium ions move through the electrolyte and become inserted into the cathode structure. This change causes the lithium to lose its valence electron and it finally goes into the wire supplying power.
Also, most people may say to never allow batteries near water, and this is because lithium is VERY reactive to water and similar liquids. It is a highly reactive material.