Lithium-ion (Li-I) batteries store electricity through a reversible chemical reaction. The basic components are a container, electrodes, and an electrolyte. By loading the battery, the electricity is transformed into chemical energy, while during discharge, electrochemical reactions occur at the two electrodes generating a flow of electrons through an external circuit (DNV KEMA, 2013).
Li-ion batteries can be used for a variety of applications in large-scale energy storage such as frequency regulation, temporal storage, and integrating renewables into the grid (making them more dispatchable). This factsheet focuses on long-term electricity storage applications with high energy capacity and discharge times of over 1 hour.