Cross-linked compound particle and secondary battery including the same

1. A compound particle comprised in an electrolyte for a lithium-ion polymer battery, wherein the compound particle comprises:

a monomer and a polymerization initiator, as a core; and

a film as a shell,

wherein the monomer is acrylonitrile,

wherein the film comprises a thermoplastic resin that is polyacrylonitrile (PAN), and

wherein the polymerization initiator is a photoinitiator, a thermoinitiator, a radiation initiator or a mixture thereof.

2. The compound particle comprised in an electrolyte for a lithium-ion polymer battery according to claim 1 , wherein the photoinitiator is at least one selected from the group consisting of α-hydroxyketone-based compounds, phenyl glyoxylate-based compounds, benzyl dimethyl ketal-based compounds, α-amino ketone-based compounds, monoacyl phosphine-based compounds, bisacyl phosphine-based compounds, phosphine oxide-based compounds, metallocene-based compounds and iodonium salts.

3. The compound particle comprised in an electrolyte for a lithium-ion polymer battery according to claim 1 , wherein the thermoinitiator is at least one selected from the group consisting of axo-based compounds, peroxy-based compounds, tert-butyl peracetate, peracetic acid and potassium persulfate.

4. The compound particle comprised in an electrolyte for a lithium-ion polymer battery according to claim 1 , wherein the radiation initiator is at least one selected from the group consisting of X-rays, alpha particle gamma rays and high-energy electron rays.

5. The compound particle comprised in an electrolyte for a lithium-ion polymer battery according to claim 1 , wherein the film further comprises a vanadium compound.

6. The compound particle comprised in an electrolyte for a lithium-ion polymer battery according to claim 5 , wherein the vanadium compound is at least one selected from the group consisting of vanadium(II) chloride, vanadium(III) chloride, vanadium tetrachloride, vanadium(II) bromide, vanadium(III) bromide, vanadium tetrabromide, vanadium(II) iodide and vanadium(III) iodide.

7. The compound particle comprised in an electrolyte for a lithium-ion polymer battery according to claim 1 , wherein the film is a copolymer of a thermoplastic resin and a vanadium compound.

8. The compound particle comprised in an electrolyte for a lithium-ion polymer battery according to claim 1 , wherein the core further comprises a foaming agent.

9. The compound particle comprised in an electrolyte for a lithium-ion polymer battery according to claim 8 , wherein the foaming agent is at least one selected from the group consisting of azodicarbonamide (ADCA), azobisisobutyronitrile (AZDN), N,N′-dimethyl-N,N′-dinitroso-terephthalate (NTA), 4,4′-oxybis(benzenesulfonyl hydrazide (OBSH), 3,3′-sulfonbis(benzene-sulfonyl hydrazide, 1,1-azobisformamide (ABFA)-(azodicarbonamide), p-ttoluenesulfonyl semicarbazide and barium azodicarboxylate (BaAC).

10. The compound particle comprised in an electrolyte for a lithium-ion polymer battery according to claim 1 , wherein a thickness of the film is 1 μm to 10 μm.

11. The compound particle comprised in an electrolyte for a lithium-ion polymer battery according to claim 1 , wherein a thickness of the film is 2 μm to 5 μm.

12. A lithium-ion polymer battery comprising the compound particle according to claim 1 .

13. A battery pack comprising the lithium-ion polymer battery according to claim 12 .

14. A device using the battery pack according to claim 13 as a power source.