Lithium ion secondary battery and method for producing the same

Abstract

Provided is a lithium ion secondary battery with enhanced charge-discharge characteristics. Disclosed is a lithium ion secondary battery comprising: a columnar anode comprising a carbon fiber assembly having an assembled carbon fiber structure, a cathode, and an ion-conducting, insulating separation film disposed between the cathode and the anode to insulate the cathode and the anode from each other, wherein a void content of the carbon fiber assembly is 20% or more and 40% or less, and wherein at least one of a lithium metal and a lithium alloy is contained in voids of the carbon fiber assembly, when the lithium ion secondary battery is in a fully charged state.

Dependencies are inferred from the claim text.