摘要:
As a positive electrode active material, a lithium transition metal complex oxide having a layered rock-salt structure containing lithium (Li) and containing magnesium atoms (Mg) substituted for part of lithium atoms (Li) is used. The lithium transition metal complex oxide is formed by chemical or electrochemical substitution of Mg atoms for part of Li atoms in LiCoO2, LiMnO2, LiFeO2, LiNiO2, or the like. A cell is prepared in which a negative electrode 2 and a positive electrode 1 including the lithium transition metal complex oxide (positive electrode active material) are disposed in a non-aqueous electrolyte 5 including a lithium salt, and part of Li in the lithium transition metal complex oxide is extracted by discharging the cell. Then, the electrolyte including Li is replaced with an electrolyte including Mg; and the cell is discharged, so that Mg atoms are substituted for the part of Li atoms in the lithium transition metal complex oxide.
摘要:
The positive electrode active material of the present invention is characterized in that its main component is a lithium metal oxide, and the lithium concentration at the surface portion of the primary particles that make up the active material is lower than that in the interior thereof. There will be less increase in internal resistance with a secondary cell made using this active material. The above-mentioned active material can be manufactured, for example, by bringing the raw active material into contact with a treatment liquid containing metal ions, and thereby lowering the lithium concentration at the surface portion of the primary particles that make up the raw active material.