US Patent 7674552 Battery having lithium fluoride/lithium hydroxide coating on anode

A battery capable of improving battery characteristics such as cycle characteristics is provided. A coating containing lithium fluoride and lithium hydroxide is provided on the surface of an anode active material layer. The ratio between lithium fluoride and lithium hydroxide is in the range, in which the Li2F+/Li2OH+ peak intensity ratio obtained in positive ion analysis by a Time of Flight-Secondary Ion Mass Spectrometry is 1 or more. The anode active material layer contains a substance containing Si or Sn as an element as an anode active material. By the coating, oxidation of the anode active material layer is inhibited, and decomposition reaction of the electrolytic solution is inhibited.