Electrode assembly and secondary battery using the same
An electrode assembly of a secondary battery includes an electrode group including a first electrode plate, a separator, and a second electrode plate that are stacked and wound, and a finishing tape attached to a predetermined region of a terminal portion of the electrode group. The finishing tape satisfies the equation Y 1 =tensile strength×thickness of finishing tape/modulus of elasticity, with Y 1 ranging from 64 to 89. Alternatively, the finishing tape includes a film layer and an adhesive layer, and satisfies the equation Y 2 =tensile strength×thickness of film layer of finishing tape/modulus of elasticity, with Y 2 ranging from 51 to 75. The finishing tape effectively prevents an increase in the thickness of a high-capacity secondary battery.
1. An electrode assembly comprising:
an electrode group comprising a first electrode plate, a separator, and a second electrode plate that are sequentially stacked and wound; and
a finishing tape attached to a predetermined region of a terminal portion of the electrode group;
wherein the finishing tape satisfies the following equation, with Y 1 ranging from 64 to 89 when a tensile strength of the finishing tape is expressed in kgf/cm 2 , a thickness of the finishing tape is expressed in μm, and a modulus of elasticity of the finishing tape is expressed in kgf/mm 2 :
Y
1
=
tensile
strength
×
thickness
of
finishing
tape
modulus
of
elasticity
.
2. The electrode assembly according to claim 1 , wherein the thickness of the finishing tape is about 15 μm to 19 μm.
3. The electrode assembly according to claim 1 , wherein the finishing tape has a width of about 10 mm or more in a wound direction of the electrode group, and a length equal to at least 25% of a total height of the electrode assembly.
4. The electrode assembly according to claim 1 , wherein the finishing tape is one of two finishing tapes respectively attached to upper and lower portions of the electrode group, each of the finishing tapes has a width of about 10 mm or more in a wound direction of the electrode group, and a sum of lengths of the two finishing tapes is equal to at least 25% of a total height of the electrode assembly.
5. The electrode assembly according to claim 1 , wherein the finishing tape has a width of about 10 mm or more in a wound direction of the electrode group, and a length equal to a total height of the electrode assembly.
6. The electrode assembly according to claim 1 , wherein the finishing tape is one two finishing tapes respectively attached to upper and lower portions of the electrode group, a sum of lengths of the two finishing tapes is equal to at least 25% of a total height of the electrode assembly, and each of the two finishing tapes has a width in a wound direction of the electrode group that enables each of the two finishing tapes to wrap around an entire outer surface of the electrode group in the wound direction of the electrode group.
7. The electrode assembly according to claim 1 , wherein the finishing tape has a length equal to a total height of the electrode assembly, and a width in a wound direction of the electrode group that enables the finishing tape to wrap around an entire outer surface of the electrode group in the wound direction of the electrode group.
8. The electrode assembly according to claim 1 , wherein the finishing tape comprises a film layer and an adhesive layer, and satisfies the following equation, with Y 2 ranging from 51 to 75 when a tensile strength of the finishing tape is expressed in kgf/cm 2 , a thickness of the film layer of the finishing tape is expressed in μm, and a modulus of elasticity of the finishing tape is expressed in kgf/mm 2 :
Y
2
=
tensile
strength
×
thickness
of
film
layer
of
finishing
tape
modulus
of
elasticity
.
9. An electrode assembly comprising:
an electrode group comprising a first electrode plate, a separator, and a second electrode plate that are sequentially stacked and wound; and
a finishing tape attached to a predetermined region of a terminal portion of the electrode group;
wherein the finishing tape comprises a film layer and an adhesive layer, and satisfies the following equation, with Y 2 ranging from 51 to 75 when a tensile strength of the finishing tape is expressed in kgf/cm 2 , a thickness of the film layer of the finishing tape is expressed in μm, and a modulus of elasticity of the finishing tape is expressed in kgf/mm 2 :
Y
2
=
tensile
strength
×
thickness
of
film
layer
of
finishing
tape
modulus
of
elasticity
.
10. The electrode assembly according to claim 9 , wherein the thickness of the finishing tape is about 15 μm to 19 μm.
11. The electrode assembly according to claim 9 , wherein the finishing tape has a width of about 10 mm or more in a wound direction of the electrode group, and a length equal to at least 25% of a total height of the electrode assembly.
12. The electrode assembly according to claim 9 , wherein the finishing tape is one of two finishing tapes respectively attached to upper and lower portions of the electrode group, each of the finishing tapes has a width of about 10 mm or more in a wound direction of the electrode group, and a sum of lengths of the two finishing tapes is equal to at least 25% of a total height of the electrode assembly.
13. The electrode assembly according to claim 9 , wherein the finishing tape has a width of about 10 mm or more in a wound direction of the electrode group, and a length equal to a total height of the electrode assembly.
14. The electrode assembly according to claim 9 , wherein the finishing tape is one of two finishing tapes respectively attached to upper and lower portions of the electrode group, a sum of lengths of the two finishing tapes is equal to at least 25% of a total height of the electrode assembly, and each of the two finishing tapes has a width in a wound direction of the electrode group that enables each of the two finishing tapes to wrap around an entire outer surface of the electrode group in the wound direction of the electrode group.
15. The electrode assembly according to claim 9 , wherein the finishing tape has a length equal to a total height of the electrode assembly, and a width in a wound direction of the electrode group that enables the finishing tape to wrap the entire outer surface of the electrode group in the wound direction of the electrode group.
16. A secondary battery comprising:
an electrode assembly comprising:
an electrode group comprising a first electrode plate, a separator, and a second electrode plate that are sequentially stacked and wound; and
a finishing tape attached to a predetermined region of a terminal portion of the electrode group;
a housing having the electrode assembly disposed therein; and
an electrolyte injected into a margin between the housing and the electrode assembly;
wherein the finishing tape satisfies the following equation, with Y 1 ranging from 64 to 89 when a tensile strength of the finishing tape is expressed in kgf/cm 2 , a thickness of the finishing tape is expressed in μm, and a modulus of elasticity of the finishing tape is expressed in kgf/mm 2 :
Y
1
=
tensile
strength
×
thickness
of
finishing
tape
modulus
of
elasticity
.
17. The secondary battery according to claim 16 , wherein the thickness of the finishing tape is about 15 μm to 19 μm.
18. The secondary battery according to claim 16 , wherein the finishing tape has a width of about 10 mm or more in a wound direction of the electrode assembly, and a length equal to at least 25% of a total height of the electrode assembly.
19. The secondary battery according to claim 16 , wherein the finishing tape comprises a film layer and an adhesive layer, and satisfies the following equation, with Y 2 ranging from 51 to 75 when a tensile strength of the finishing tape is expressed in kgf/cm 2 , a thickness of the film layer of the finishing tape is expressed in μm, and a modulus of elasticity of the finishing tape is expressed in kgf/mm 2 :
Y
2
=
tensile
strength
×
thickness
of
film
layer
of
finishing
tape
modulus
of
elasticity
.
20. A secondary battery comprising:
an electrode assembly comprising:
an electrode group comprising a first electrode plate, a separator, and a second electrode plate that are sequentially stacked and wound; and
a finishing tape attached to a predetermined region of a terminal portion of the electrode group;
a housing having the electrode assembly disposed therein; and
an electrolyte injected into a margin between the housing and the electrode assembly;
wherein the finishing tape comprises a film layer and an adhesive layer, and satisfies the following equation, with Y 2 ranging from 51 to 75 when a tensile strength of the finishing tape is expressed in kgf/cm 2 , a thickness of the film layer of the finishing tape is expressed in μm, and a modulus of elasticity of the finishing tape is expressed in kgf/mm 2 :
Y
2
=
tensile
strength
×
thickness
of
film
layer
of
finishing
tape
modulus
of
elasticity
.
21. The secondary battery according to claim 20 , wherein the thickness of the finishing tape is about 15 μm to 19 μm.
22. The secondary battery according to claim 20 , wherein the finishing tape has a width of about 10 mm or more in a wound direction of the electrode group, and a length equal to at least 25% of a total height of the electrode assembly.