How a battery works

Batteries store electricity in the form of chemical energy to use when they are connected to a device.

Batteries contain a positive cathode and a negative anode. These electrode terminals are made up of different materials depending on the battery type. When a device is connected to the battery, a chemical reaction occurs that generates positively charged ions and negatively charged electrons. The ions flow through electrolyte to the cathode; whereas the electrons (that cannot penetrate the electrolyte) travel around the outer circuit powering a device en route to the cathode. Disposable batteries die when the anode or cathode runs out of the chemical needed to catalyse the reaction.

Rechargeable batteries

When a device is recharged, electric energy from the charger (such as a phone charger plugged into a wall) is applied to the chemical system to reverse the process and restore the battery’s charge. Rechargeable batteries are thought to degrade because of the irregular movement of ions in the electrolyte.

Types of rechargeable batteries

The lifetime, cost, energy storage and re-usability of the battery are determined by the material used. This also dictates whether the battery is best used for devices that do not consume much energy or in those that do. Capacity Ability to supply electric energy Performance How well high-drain devices are powered Recharge cycles The number of times the battery can be recharged in its lifetime Toxicity Composition and ease of recycling Affordability Cost to consumer

Credit: Source: batteryuniversity.com
Credit: Source: batteryuniversity.com

Batteries and the smart grid

Sources of renewable energy such as wind and the Sun provide only intermittent power. Storing excess energy on sunny or windy days is of paramount importance. Several types of battery are being explored for their use as grid storage.

Credit: Source: B. Berger. (Fraunhofer ISE, 2014)

Resource scarcity

Batteries contain materials that could eventually run out. Countries that are rich in these resources could one day hold the same sway as today’s oil-rich countries. Lithium is one of the main concerns — demand for the metal has almost doubled in the past five years, with most of the world’s supply coming from Latin America.

Credit: Sources: minerals.usgs.gov/minerals/pubs/commodity/lithium/index.html

The rechargeable-battery market of the future looks set to be dominated by lithium-ion batteries.

Credit: Sources: bernstein.com
Credit: Source: batteryuniversity.com
Credit: Source: batteryuniversity.com
Credit: Source: B. Berger. (Fraunhofer ISE, 2014)
Credit: Sources: minerals.usgs.gov/minerals/pubs/commodity/lithium/index.html
Credit: Sources: bernstein.com