First Steps in Developing Cement-Based Batteries to Power Cathodic Protection of Embedded Steel in Concrete

This paper presents the first steps in developing innovative cement-based batteries to power cathodic protection in reinforced concrete structures. Initial electrical outputs of 1.55V and 23mA have been found to be sufficient to polarise prescribed corrosion currents of 20mA per m2 of embedded steel. Cathodic protection is a well-developed and powerful technique to limit the effects of steel reinforcement corrosion. However, as it requires an electrical supply day and night, it is often powered by non-environmentally friendly diesel generators or connected to the electrical grid. This paper focuses on increasing the ionic conductivity of the solution in the cement pores, increasing the porosity of the cement, examining ways of sealing moisture into the cement and comparing different electrode materials and treatments. The batteries presented consist of different combinations of Portland cement, water, carbon black and salt solutions with embedded copper acting as the cathode and magnesium, aluminium or zinc cast as the anode. The preliminary findings demonstrate that cementbased batteries can produce sufficient sustainable electrical outputs with the correct materials and arrangement of cast-in anodes. Work is ongoing to determine how these batteries can be recharged using photovoltaics which will further enhance their sustainability properties.