Electrode composite body, method of manufacturing electrode composite body, and lithium battery

A method of manufacturing an electrode composite body, comprising:

• supplying a solution of a first inorganic solid electrolyte to come into contact with an active material molded body including active material particles which include a lithium composite oxide and have a particle shape, and a communication hole that is provided between the active material particles so as to impregnate the solution into the communication hole;
• heating the active material molded body that is impregnated with the solution;
• supplying a solid material of a second inorganic solid electrolyte, of which a composition is different from a composition of the first inorganic solid electrolyte and contains boron as a constituent element, to come into contact with the active material molded body;
• melting the solid material of the second inorganic solid electrolyte, and impregnating the resultant molten material of the second inorganic solid electrolyte into the communication hole;
• and
• solidifying the molten material to be crystallized.