Lithium-Ion Battery
A lithium-ion battery (Li-ion battery) is a rechargeable battery that stores and releases energy by moving lithium ions through an electrolyte between two electrodes while electrons flow through the external circuit.
Why it matters in an EV
Most current battery-electric and plug-in hybrid vehicles use lithium-ion traction batteries. The term describes a battery family rather than one fixed recipe: electrode materials, electrolyte formulation, cell construction, and pack integration can differ. This is why two lithium-ion EV batteries can behave differently in everyday use.
A lithium-ion label alone therefore does not specify energy density, charging performance, service life, or safety. Those outcomes also depend on cell design, operating limits, thermal management, and the battery-management system.
For the detailed chemistry, components, and design trade-offs, see Cell Chemistry & Components.