Extinguishing composition, method for preparing the same, secondary battery and battery pack

A method for preparing an extinguishing composition, the method comprising:

• mixing a thermoplastic resin with a solvent to prepare a capsule solution in which the thermoplastic resin is dissolved;
• adding a plurality of extinguishing materials to the capsule solution to apply the capsule solution to surfaces of the plurality of extinguishing materials;
• and
• heating the plurality of extinguishing materials coated with the capsule solution to evaporate the solvent contained in the capsule solution so as to capsulate the thermoplastic resin remaining on the surfaces of the plurality of extinguishing materials, thereby preparing the extinguishing composition.

A secondary battery comprising:

• an electrode assembly in which a plurality of electrodes and a plurality of separators are alternately stacked;
• a case in which the electrode assembly is accommodated;
• an electrolyte stored in the case so as to be impregnated into the electrode assembly;
• and
• an extinguishing composition provided in at least one of the electrodes, the separators, or the electrolyte,
• wherein the extinguishing composition comprises an extinguishing material and a capsule containing the extinguishing material, and
• wherein the extinguishing material comprises calcium bromide.