Transactions of The Electrochemical Society · 1947 · 11 citations · 0 references
The preparation of the perchloric acid primary cell is described. The cell contains plated lead dioxide positive plates, metallic lead negative plates, and aqueous perchloric acid electrolyte. The soluble nature of the discharge product, lead perchlorate, permits relatively high currents to be drawn from the cell at temperatures as low as −20° C. Discharge data at current densities from 0.045 to 3.33 amp./sq. in. (0.70 to 51.6 amp./dm. 2 ), temperatures from −40° C to +40° C, and acid concentrations from 40% to 73% are given. Acid efficiencies at each concentration based on the equation : <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="block" id="ML1" overflow="scroll"> <mml:msub> <mml:mi mathvariant="normal">PbO</mml:mi> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> <mml:mo>+</mml:mo> <mml:mi mathvariant="normal">Pb</mml:mi> <mml:mo>+</mml:mo> <mml:mn>4</mml:mn> <mml:msub> <mml:mi mathvariant="normal">HClO</mml:mi> <mml:mrow> <mml:mn>4</mml:mn> </mml:mrow> </mml:msub> <mml:mo>=</mml:mo> <mml:mn>2</mml:mn> <mml:mi mathvariant="normal">Pb</mml:mi> <mml:msub> <mml:mfenced close=")" open="("> <mml:mrow> <mml:msub> <mml:mi mathvariant="normal">ClO</mml:mi> <mml:mrow> <mml:mn>4</mml:mn> </mml:mrow> </mml:msub> </mml:mrow> </mml:mfenced> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> <mml:mo>+</mml:mo> <mml:mn>2</mml:mn> <mml:msub> <mml:mo>H</mml:mo> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> <mml:mo>O</mml:mo> </mml:math> approach 100% as the current density is reduced. Efficiencies greater than 100% at low rates and high temperatures indicate a two‐stage discharge process under these conditions with the formation of basic perchlorates as reaction products. The use of negative materials other than lead is discussed.