The Battery

Electrolysis uses electrical energy to stimulate a chemical reaction; batteries use this chemical reaction to produce electrical energy as a flow of electrons – an electric current – into an external circuit. The materials in the battery are consumed in the process. Energy is then stored in the battery.

Any batteries used in e.g. a vehicle must be rechargeable, i.e. the chemical changes during discharge must be reversed. Batteries must also be light and occupy a relatively small volume, and be capable of being recharged quickly.

Despite much intensive research these criteria are still a long way from being met. In addition, recharging batteries usually involves electricity that is generated in fossil fuel power stations and wastefully transmitted over long distances (which is inefficient and also releases carbon dioxide and other much more undesirable gases). The normal vehicle battery is kept charged by using some of the energy released by burning the fuel in the ICE.