A new lead/lead sulphate reference electrode for lead/acid battery research

Abstract

A description is given of a new reference electrode made from the porous lead plate material used in the lead/acid battery. The reproducibility and stability of the equilibrium potential is achieved by keeping the state-of-charge at 0.90 ± 0.05, and by using 4.80 M (25°C) H₂SO₄ solution as electrolyte. The latter avoids passivation effects and minimises liquid junction potentials with the test solution. The electrode, represented as Pb(porous)/PbSO₄, H₂SO₄ (4.80 M), shows a value of 0.9678 ± 0.0005 V versus an Hg/Hg₂SO₄ electrode at 25 ° C in the same solution. This potential is indefinitely stable if the electrode is reconditioned every three months by a charge-discharge cycle using conventional PbO₂ lead/acid battery plates as counter electrodes.