POSITIVE ELECTRODE FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERIES, AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

This positive electrode for nonaqueous electrolyte secondary batteries is provided with a positive electrode core body and a positive electrode mixture layer that is formed on the surface of the positive electrode core body. The positive electrode mixture layer contains a positive electrode active material that is mainly composed of a lithium transition metal composite oxide which contains 70% by mole or more of Ni relative to the total number of moles of the metal elements excluding Li. In addition, the positive electrode core body has a thermal conductivity X of from 50 to 155 W/m·K (25°C). It is preferable that the upper limit Y1 and the lower limit Y2 of the median value Y in the circularity distribution of the lithium transition metal composite oxide relative to the thermal conductivity X of the core body respectively satisfy the conditions of formula (1) and formula (2) described below. Formula (1): Y1 = 0.9322(X-0.987) Formula (2): Y2 = 0.1613(X-0.746) - 0.0005