ALL-SOLID LITHIUM SECONDARY BATTERY

摘要

An exemplary lithium secondary battery includes: a positive electrode including a positive-electrode active substance layer 103; a negative electrode; and a solid electrolyte layer 104. The positive-electrode active substance layer 103 comprises lithium cobaltate, and has an α-NaFeO2 type crystal structure. The positive-electrode active substance layer 103 includes a lower layer 103a, and an upper layer 103b interposed between the lower layer and the solid electrolyte layer. The lower layer 103a is oriented in the (110) plane. The upper layer 103b is composed only of first regions 103b1 oriented in the (110) plane and second regions 103b2 oriented in the (018) plane, the first and second regions being mixedly present in the xy plane of the positive-electrode active substance layer. The solid electrolyte layer 104 comprises lithium lanthanum titanate, and has a tetragonal perovskite-type crystal structure. The solid electrolyte layer 104 is oriented in the (110) or (102) plane.

主权项

1. An all-solid lithium secondary battery comprising:
a positive electrode including a positive-electrode active substance layer; a negative electrode including a negative-electrode active substance layer, the negative-electrode active substance layer allowing lithium ions to be inserted and allowing inserted lithium ions to be released; and a solid electrolyte layer interposed between the positive electrode and the negative electrode, wherein, the positive-electrode active substance layer comprises lithium cobaltate, and has an α-NaFeO2 type crystal structure; given an x axis and a y axis which are defined as two axes that are parallel to a principal face of the positive-electrode active substance layer, and a z axis which is defined as an axis that is perpendicular to the principal face, the positive-electrode active substance layer has a multilayer structure including a lower layer and an upper layer which is interposed between the lower layer and the solid electrolyte layer; the lower layer is oriented in the (110) plane; the upper layer is composed only of first regions oriented in the (110) plane and second regions oriented in the (018) plane, the first regions and second regions being mixedly present in an xy plane of the positive-electrode active substance layer; the solid electrolyte layer comprises lithium lanthanum titanate and has a tetragonal perovskite-type crystal structure; and the solid electrolyte layer is oriented in the (110) plane or the (102) plane.