Positive electrode material, its manufacturing method and lithium batteries

摘要

The invention provides a positive electrode material for lithium batteries in which the discharge rate characteristic and the battery capacity are hardly deteriorated in an environment of low temperature of -30 °C, a method of manufacturing the positive electrode material and lithium secondary batteries using that positive electrode material. The positive electrode material of the present invention comprises secondary particles (2) composed of a network of primary particles (1) wherein the sum of the contact lengths of the primary particles (1) is equivalent to 10 to 70 % of the length of the whole periphery of the primary particles (1) in a section of the primary particles being in contact with each other. The voidage of the secondary particles (2) is preferably 2.5 to 35 % of the sectional area of the secondary particles (2).