A lithium-ion or Li-ion battery is a type of rechargeable battery that uses the reversible intercalation of Li+ ions into electronically conducting solids to store energy. In comparison with other commercial rechargeable batteries, Li-ion batteries are characterized by higher specific energy, higher energy density, higher energy efficiency, a longer cycle life, and a longer calendar life. Also noteworthy is a dramatic improvement in lithium-ion battery properties after their market introduction in 1991: over the following 30 years, their volumetric energy density increased threefold while their cost dropped tenfold. In late 2024 global demand passed 1 Terawatt-hour per year, while production capacity was more than twice that. The invention and commercialization of Li-ion batteries may have had one of the greatest impacts of all technologies in human history, as recognized by the 2019 Nobel Prize in Chemistry. More specifically, Li-ion batteries enabled portable consumer electronics, laptop computers, cellular phones, and electric cars. Li-ion batteries also see significant use for grid-scale energy storage as well as...