Positive electrode material and battery comprising it

It is the object of the invention to provide a cathode material capable of improving charge-and-discharge cycle characteristics and a battery using the cathode material. A rolled electrode body (20) is provided, the rolled electrode body being comprised of a strip-shaped cathode (21) and a strip-shaped anode (22) with a separator (23) sandwiched in-between. Lithium metal precipitates on the anode (22) in the middle of charge, and a capacity of the anode (22) is expressed by a sum of a capacity component obtained through insertion and extraction of lithium and a capacity component obtained through precipitation and dissolution of lithium. The cathode (21) includes lithium-containing oxide as the cathode material capable of insertion and extraction of lithium, which is expressed in a chemical formula LixMI1-yMIIyO2. MI corresponds to Co or Ni, and MII corresponds to a transition metal element except for MI. Therefore, charge-and-discharge cycle characteristics can be improved.