WET MIXTURE, COATED LITHIUM-CONTAINING POSITIVE ELECTRODE ACTIVE MATERIAL PARTICLES, AND METHOD OF PRODUCING LITHIUM ION SECONDARY BATTERY, AND WET MIXTURE, COATED LITHIUM-CONTAINING POSITIVE ELECTRODE ACTIVE MATERIAL PARTICLES, AND LITHIUM ION SECONDARY BATTERY

A method of producing a wet mixture includes a stirring and mixing process in which lithium-containing positive electrode active material particles having surplus lithium compounds on the surface and crystalline ferroelectric ceramic particles are dried, stirred and mixed to obtain a mixed powder; and a solution mixing process in which a lithium conductor forming solution is mixed with the mixed powder to obtain a wet mixture containing coated lithium-containing positive electrode active material particles having a coating which is made of an amorphous lithium conductor and in which the ferroelectric ceramic particles are dispersed on the surface of the lithium-containing positive electrode active material particles.