Secondary battery pouch with enhanced insulation property, and method for manufacturing same
The present disclosure relates to a secondary battery pouch with an enhanced insulation property, and a method for manufacturing the same, and more specifically, to a secondary battery pouch for preventing occurrence of cracks in a sealing portion of a periphery of a pouch in a completed pouch-type secondary battery, particularly at a folded portion of the sealing portion, and a method for manufacturing the same.
1. A secondary battery pouch, wherein microcapsules of a core-shell structure are applied between an inner resin layer of an upper pouch and an inner resin layer of a lower pouch along a to-be-folded portion of the pouch,
the microcapsules include an elastic thermoplastic resin in the core thereof, and
the shell is formed of one or a mixture of at least two selected from the group consisting of polyethylene, polyethylene terephthalate, polypropylene, polycarbonate, polyvinyl chloride, polyacetal, polyoxymethylene, polybutylene terephthalate, acrylonitrile-butadiene-styrene and ethylene-vinyl alcohol copolymer.
2. The secondary battery pouch of claim 1 , wherein at least a portion of the shell is melted or destructed by thermal bonding process at from 170° C. to 200° C.
3. The secondary battery pouch of claim 1 , wherein the elastic thermoplastic resin is melted at from 170° C. to 200° C. and cured.
4. The secondary battery pouch of claim 1 , wherein the elastic thermoplastic resin is one or a mixture of at least two selected from epoxy compounds, acrylic compounds, silicones, rubber, polyurethanes, and elastomer.
5. The secondary battery pouch of claim 1 , wherein the microcapsules have an average diameter ranging from 0.5 μm to 2 μm.
6. The secondary battery pouch of claim 1 , wherein a thickness of the shell corresponds to from ⅕ to 1/10 the diameter of microcapsules.
7. A pouch-type secondary battery comprising:
an electrode assembly including a cathode, an anode, and a separator interposed between the cathode and the anode; and
the secondary battery pouch according to claim 1 , the secondary battery pouch having an accommodating portion to receive the electrode assembly therein,
wherein a sealing portion is formed on two sides or three sides of the secondary battery pouch,
the sealing portion is folded, and
a cured elastic thermoplastic resin is further formed in the folded portion.
8. The pouch-type secondary battery of claim 7 , wherein the cured elastic thermoplastic resin is one or a mixture of at least two selected from epoxy compounds, acrylic compounds, silicones, rubber, polyurethanes, and elastomer.
9. A method for manufacturing a secondary battery pouch of claim 1 , the method comprising:
applying the microcapsules of the core-shell structure including the elastic thermoplastic resin in the core thereof by screen printing, inkjet printing or laser printing, between the inner resin layer of the upper pouch and the inner resin layer of the lower pouch along the to-be-folded portion of the pouch.
10. A method for manufacturing a pouch-type secondary battery comprising:
receiving a secondary battery in the secondary battery pouch of claim 1 ;
heat-sealing a periphery of the secondary battery pouch; and
folding a sealing portion.
11. A method for manufacturing a pouch-type secondary battery comprising:
receiving a secondary battery in a secondary battery pouch, wherein microcapsules of a core-shell structure are applied between an inner resin layer of an upper pouch and an inner resin layer of a lower pouch along a to-be-folded portion of the pouch, the microcapsules include an elastic thermoplastic resin in the core thereof;
heat-sealing a periphery of the secondary battery pouch; and
folding a sealing portion,
wherein the heat-sealing is performed by the thermal bonding which is carried out at a temperature ranging from 170° C. to 200° C.