Key Milestones in Electrochemistry

1789 — Luigi Galvani discovers "animal electricity" by observing frog legs twitching when touched by two different metals. First hint of bioelectricity and galvanic action.

1799 — Alessandro Volta constructs the first electrochemical battery ("Voltaic pile") — alternating Zn and Ag discs separated by cloth soaked in brine. Demonstrated sustained electrical current. Named after him: Volt (V).

1800 — William Nicholson and Anthony Carlisle perform first electrolysis of water using Volta's pile, decomposing water into $H_{2}$ and $O_{2}$.

1834 — Michael Faraday formulates the laws of electrolysis (Faraday's First and Second Laws). Coined terms: electrode, anode, cathode, electrolyte, ion. Faraday constant F ≈ 96500 C/mol named after him.

1868 — Georges Leclanché invents the Leclanché cell (forerunner of modern dry cell), using Zn and Mn$O_{2}$ in ammonium chloride electrolyte, EMF ≈ 1.5 V.

1884 — Svante Arrhenius proposes ionic dissociation theory — electrolytes dissociate into ions in solution — explaining conductance data of weak vs strong electrolytes.

1889 — Hermann Walther Nernst derives the Nernst equation, relating electrode potential to ion concentration and temperature. Foundation for quantitative electrochemical calculations.

1890s — Lead storage battery developed; widely adopted for automobile starting in early 20th century (2 V/cell, 12 V total for 6 cells).

1920s — Peter Debye and Erich Hückel develop the Debye-Hückel theory of strong electrolytes; Onsager extends it to the Debye-Hückel-Onsager equation for molar conductivity (Λm = Λ°m − A√C).

1959 — Francis Thomas Bacon develops the first practical $H_{2}$-$O_{2}$ fuel cell for NASA. Used in Apollo space program (provided both electricity and drinking water).