Rechargeable Batteries vs. Normal Batteries
Normal batteries (non-rechargeable/ primary cells) and rechargeable batteries (secondary cells) create current in the exact same manner as each other: through an electrochemical reaction involving an electrolyte, anode and cathode.
Primary batteries have a single-use, like those used in a remote control. The reaction that happens in the cell is irreversible and will eventually stop occurring, meaning the battery will no longer produce an electrical current. The battery is said to be discharged or dead, and needs to be thrown away. However in secondary, rechargeable batteries the reaction can be reversed by providing electrical energy back to the battery. For example, when you charge your phone, there is an electrical current flowing from the charger into the battery.
Using rechargeable batteries means you don't have to replace a battery every time it discharges. In fact, it can be used up 500 times.
Key Benefits of using rechargeable batteries
- more cost effective - it's cheaper to recharge a battery than to keep buying a new one
- reduction in waste - due to the dangerous chemicals in batteries they need to be disposed of safely
- consistent voltage - disposable batteries start at 1.5 volts at the beginning of their life and this progressively get lower until it they are dead. Rechargeable batteries use 1.2 volts of energy the entire time they are in use
Types of Rechargeable Batteries
- Some of the most commonly used secondary batteries today are lithium-ion (Li-ion) batteries, which are found in most modern electronic devices. These typically contain a cathode made of lithium cobalt dioxide, a carbon anode and an electrolyte containing dissolved lithium salt.
- Other rechargeable battery types include nickel-cadmium (NiCd) and nickel-metal hydride (Ni-MH). Both are commonly made as an AA battery size but NiCd batteries the typical form of battery used for electric vehicles and cordless power tools.
- The lead-acid (Pb-acid) battery is used to power cars and other vehicles for starting, lighting and ignition.
All of these rechargeable batteries operate under the same principle: when you plug the battery into a power source, the flow of electrons changes direction, and the anode and the cathode are returned to their original states.
