Study on a new single flow acid Cu–PbO2 battery

The present paper reports a new single flow acid battery, Cu–H2SO4–PbO2 battery, in which smooth graphite is employed as negative electrode, lead dioxide as positive electrode and the intermixture of H2SO4–CuSO4 as electrolyte. The reaction Cu⇌Cu2+ takes place on the negative electrode. The working process of the battery is only the circulation of H2SO4–CuSO4 intermixture by means of a single pump. No cationic membrane is needed. A miniature acidic copper single flow battery with a rated capacity of 2000 mAh can offer a discharge voltage of 1.29 V, an average coulombic efficiency of 97% and an energy efficiency of 83% during 450 cycles at a charge/discharge current of 1000 mA.