What type of reaction characterizes rechargeable batteries?

Rechargeable batteries operate based on reversible reactions, which is a key characteristic that allows them to be charged and discharged multiple times. In a rechargeable battery, chemical reactions take place during discharge (when the battery is providing power) and can be reversed during charging (when electrical energy is supplied to the battery).

The reversible nature of these reactions enables the chemical reactants to convert back into their original forms, allowing the energy to be stored and released repeatedly. This is fundamental for the functionality of rechargeable batteries, such as lithium-ion batteries commonly used in many electronic devices. Hence, the primary reaction type which defines the operation of these batteries is reversible reactions.