Electrochemistry is the branch of physical chemistry that studies the relationship between electricity, as a measurable and quantitative phenomenon, and identifiable chemical change, with either electricity considered an outcome of a particular chemical change or vice versa. These reactions involve electric charges moving between electrodes and an electrolyte (or ionic species in a solution). Thus electrochemistry deals with the interaction between electrical energy and chemical change.When a chemical reaction is caused by an externally supplied current, as in electrolysis, or if an electric current is produced by a spontaneous chemical reaction as in a battery, it is called an electrochemical reaction. Chemical reactions where electrons are transferred directly between molecules and/or atoms are called oxidation-reduction or (redox) reactions. In general, electrochemistry describes the overall reactions when individual redox reactions are separate but connected by an external electric circuit and an intervening electrolyte.

電化學(xué)是物理化學(xué)的一個分支，研究電作為一種可測量和定量的現(xiàn)象與可識別的化學(xué)變化之間的關(guān)系，電被認(rèn)為是特定化學(xué)變化的結(jié)果，反之亦然。這些反應(yīng)涉及電極和電解質(zhì)（或溶液中的離子物質(zhì)）之間移動的電荷。因此，電化學(xué)研究電能和化學(xué)變化之間的相互作用。當(dāng)化學(xué)反應(yīng)是由外部提供的電流引起的，如在電解中，或如果電流是由電池中的自發(fā)化學(xué)反應(yīng)產(chǎn)生的，則稱為電化學(xué)反應(yīng)。電子直接在分子和/或原子之間轉(zhuǎn)移的化學(xué)反應(yīng)稱為氧化還原或（氧化還原）反應(yīng)。一般來說，電化學(xué)描述的是單個氧化還原反應(yīng)是分開的，但由外部電路和中間電解質(zhì)連接的總反應(yīng)。