Packaging for flexible secondary battery and flexible secondary battery comprising the same

A packaging for a flexible secondary battery configured to be disposed around an outer surface of an electrode assembly of the flexible secondary battery, the packaging comprising:

• a heat shrink layer;
• a reduced graphene oxide layer disposed on the heat shrink layer, the reduced graphene oxide layer including a plurality of reduced graphene oxide sheets and metal cations;
• and
• a sealant layer disposed on the reduced graphene oxide layer,
• wherein the plurality of reduced graphene oxide sheets in the reduced graphene oxide layer forms electrostatic interactions between adjacent sheets of the plurality of reduced graphene oxide sheets via the metal cations,
• wherein each sheet of the plurality of reduced graphene oxide sheets has a structure of one to three layers of reduced graphene oxide particles and a thickness ranging from 1 nm to 10 μm,
• wherein the reduced graphene oxide layer has a thickness ranging from 100 nm to 100 μm, and
• wherein the metal cations include at least one of Li+, K+, Mg2+, Ca2+, Pb2+, Co2+, Al3+, Cr3+, or Fe3+.