Positive electrode active material of power storage device, power storage device, electrically propelled vehicle, and method for manufacturing power storage device

A manufacturing method of a power storage device comprising the step of:

• forming a positive electrode comprising the steps of:
• performing a first grinding on a mixture of raw materials;
• performing a first baking on the mixture after the first grinding;
• performing a first pressure treatment before the first baking;
• performing a second grinding on the mixture after the first baking;
• adding a saccharide to the mixture after the second grinding, so that a surface of the mixture is supported by a carbon material;
• performing a second baking on the mixture after the adding at a higher temperature than the first baking, so that a positive electrode active material is formed;
• and
• performing a second pressure treatment before the second baking,
• wherein the positive electrode active material has a surface area per unit mass of 24 m2/g or more and 27.5 m2/g or less, and an X-ray diffraction half width of greater than or equal to 0.13° and less than 0.17°.