The three participants in the electrochemical reactions in a lithium-ion battery are the anode, the cathode, and the electrolyte. Both the anode, which is a lithium-containing compound, and the cathode, which is a carbon-containing compound, are materials into which lithium ions can migrate. The electrolyte is a lithium salt in an organic solvent. When a lithium-based cell is discharging, the positive lithium ion is extracted from the cathode and inserted into the anode, releasing stored energy in the process. When the cell is charging, the reverse occurs.