The term "battery" refers to a device that stores chemical energy and converts it into electrical energy through an electrochemical reaction. Batteries consist of one or more cells, each containing an anode, cathode, and electrolyte. The anode and cathode are materials that differ significantly in their electronegativity, leading to a potential difference. When connected in a circuit, an electrochemical reaction occurs whereby electrons flow from the anode to the cathode through an external circuit, generating an electric current. This flow continues until the reactants are exhausted, at which point the battery is considered "dead."
Batteries come in various forms and sizes, tailored to diverse applications. Common types include alkaline batteries, used in everyday household items like remote controls and toys; lithium-ion batteries, favored in mobile devices and electric vehicles due to their high energy density and rechargeability; and lead-acid batteries, which are typically used in automotive starters. The choice of battery depends on factors such as capacity, voltage requirements, stability, life cycle, and environmental conditions under which the battery needs to operate.
The history of batteries can be traced back to the 18th century, with the invention of the voltaic pile by Alessandro Volta in 1800, often considered the first true battery. Volta's discovery led to significant advancements in the field of electrochemistry, paving the way for the development of the Daniell cell in 1836 by John Frederic Daniell, which was the first practical source of electricity. This evolution continued with the introduction of the Leclanché cell in 1866, which later evolved into the modern zinc-carbon battery, a staple in households worldwide.
Today, the development of batteries focuses heavily on improving energy density, reducing costs, and enhancing sustainability. Innovations such as solid-state batteries, which replace the liquid electrolyte with a solid, promise higher safety and energy density. The push towards renewable energy sources and the increasing demand for electric vehicles have also stimulated research in areas like battery recycling and alternative materials such as lithium-air or sodium-ion, which aim to reduce reliance on rare materials like cobalt and lithium. As this field evolves, the societal shift toward sustainable energy solutions continues to drive the advancement of battery technology.