All-Solid-State Thick-Film Battery

An all-solid-state Li-ion secondary battery based on Li/LiSiPO/LiCoO2 has been developed and the cell performance has been evaluated. The electrolyte and cathode were fabricated by tape casting. The charge and discharge behaviour of the cell at constant current was investigated in view of the fact of lower conductivities of solid conductors compared to liquid electrolytes and the internal resistance of the solid-solid interface. Solutions to these problems have been investigated by varying the fabrication methods. A major advantage was the application of pyrolyzable pore formers in the cathode green tape in order to produce a porous cathode matrix. This result indicates that the interfacial contacts between solid electrolytes and electrodes can be greatly improved. Also, the internal resistance may be further decreased by tape casting of thinner electrolyte films. In conclusion, the tape casting method is very promising for the development of high performance all-solid-state Li-ion batteries.