Solid electrolyte material, lithium battery, and method of producing solid electrolyte material

#The present invention relates to a solid electrolyte material having excellent Li ion conductivity.

#In accordance with a rapid spread of information relevant apparatuses and communication apparatuses such as a personal computer, a video camera and a portable telephone in recent years, as a power source thereof the development of a battery to be utilized has been emphasized. The development of a high-output and high-capacity battery for an electric automobile or a hybrid automobile has been advanced also in the automobile industry. A lithium battery has been presently noticed from the viewpoint of a high energy density among various kinds of batteries.

#Liquid electrolyte containing a flammable organic solvent is used for a presently commercialized lithium battery, so that the installation of a safety device for restraining temperature rise during a short circuit and the improvement in structure and material for preventing the short circuit are necessary therefor. On the contrary, a lithium battery all-solidified by replacing the liquid electrolyte with a solid electrolyte layer is conceived to intend the simplification of the safety device and be excellent in production cost and productivity for the reason that the flammable organic solvent is not used in the battery.

#FIG. 1 is a ternary view explaining a solid electrolyte material of the present invention.

#FIG. 2 is a schematic cross-sectional view showing an example of a lithium battery of the present invention.

#FIG. 3 is a schematic cross-sectional view showing an example of a method of producing a solid electrolyte material of the present invention.

#A solid electrolyte material, a lithium battery and a method of producing a solid electrolyte material of the present invention are hereinafter described in detail.

#A. Solid Electrolyte Material

#A solid electrolyte material of the present invention is first described. A solid electrolyte material of the present invention is represented by a general formula: Lix(La1-aM1a)y(Ti1-bM2b)zOδ, characterized in that “x”, “y”, and “z” satisfy relations of x+y+z=1, 0.652≦x/(x+y+z)≦0.753, and 0.167≦y/(y+z)≦0.232; “a” is 0≦a≦1; “b” is 0≦b≦1; “δ” is 0.8≦δ≦1.2; “M1” is at least one selected from the group consisting of Sr, Na, Nd, Pr, Sm, Gd, Dy, Y, Eu, Tb, and Ba; and “M2” is at least one selected from the group consisting of Mg, W, Mn, Al, Ge, Ru, Nb, Ta, Co, Zr, Hf, Fe, Cr, and Ga.