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How do lithium batteries provide high voltage and high energy density?

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Cross-section diagram of an alkaline-manganese dioxide battery showing labeled internal components, including the steel-plated covers, cathode, anode gel, current collector, separator, steel can, and brass rivet. — battery Cutaway view of an alkaline–manganese dioxide power cell.

Lithium batteries achieve high voltage and energy density primarily due to the unique chemical properties of lithium. As an alkali metal, lithium is highly chemically active and possesses a large negative electrochemical potential, which allows it to serve as an efficient anode (negative electrode).123

The high energy density is a result of lithium's light weight and its ability to participate in high-energy electrochemical reactions. Because of this high chemical activity, these batteries utilize nonaqueous electrolytes, which enable the cells to operate at higher voltages—often near 3.6 volts—compared to traditional aqueous systems.21

In lithium-ion cells, high voltage and energy density are maintained by using specially selected carbon powders as an anode base. Lithium ions are inserted into this structure to form a compound that provides stable, high-performance power. While lithium-metal anode batteries offer even higher theoretical energy densities, lithium-ion designs are widely used in consumer electronics because they balance high energy output with improved safety through the use of these carbon-based anodes.41