Performance of LiCoO2 cathodes, prepared using the Pechini method, in molten carbonate fuel cells

The Pechini method has successfully been used to fabricate a high-purity, ultrafine, homogeneous LiCoO2 powder. The powder has been used to cast tapes together with a plastic pore former. Sintered tapes show a bimodal pore size distribution comparable to that of state-of-the-art NiO cathodes and a homogeneous distribution of the pores throughout the tape. It is also shown that total porosity can be changed while retaining approximately the same pore size distribution using different sintering temperatures. Cell characterization, in a 3 cm(2) lab cell, was performed on three cathodes sintered at 850. 900, and 950 degrees C with total porosity ranging from 57 to 69%. It is concluded that (i) the selected chemical powder preparation technique provides pure, stable LiCoO2 with high surface area and high electrical conductivity and (ii) the cathode sintered at 900 degrees C possesses a compromise of both phase purity, maximum possible porosity and particle size, and hence gives a cathode polarization of 88 mV for 160 mA/cm(2) at 650 degrees C under optimum electrolyte content, which is comparable to state-of-the-art lithiated NiO. However, the voltage loss due to the interface resistance between current collector and electrode is on the order of 100 mV, which leads to a less advantageous total cathode performance.