TECHNICAL FIELD
[0002] The present invention relate to a secondary battery.
BACKGROUND ART
[0003] Secondary batteries are rechargeable unlike primarily
batteries, and also, the possibility of compact size and high
15 capacity is high. Thus, recently, many studies on secondary
batteries are being carried out. As technology development
and demands for mobile devices increase, the demands for
secondary batteries as energy sources are rapidly increasing.
[0004] Rechargeable batteries are classified into coin type
20 batteries, cylindrical type batteries, prismatic type
batteries, and pouch type batteries according to a shape of a
battery case. In such a secondary battery, an electrode
assembly mounted in a battery case is a chargeable and
dischargeable power generating device having a structure in
25 which an electrode and a separator are stacked.
2
[0005] The electrode assembly may be approximately classified
into a jelly roll type electrode assembly in which a separator
is interposed between a positive electrode and a negative
electrode, each of which is provided as the form of a sheet
5 coated with an active material, and then, the positive
electrode, the separator, and the negative electrode are wound,
a stacked type electrode assembly in which a plurality of
positive and negative electrodes with a separator therebetween
are sequentially stacked, and a stack/folding type electrode
10 assembly in which stacked type unit cells are wound together
with a separation film having a long length.
[0006] Currently, as the energy density of the secondary
battery increases, an amount of gas generated inside the
secondary battery increases. In addition, solutions are
15 needed because the secondary battery is bent due to the gas
generation to cause defects.
[0007] In addition, the defect rate due to the gas generation
is expected to be accelerated as the energy density of the
secondary battery increases.
20 [0008] There is an issue in that the amount of moisture that
is diffused from the outside while extracting the generated
gas to the outside has to be minimized. When the moisture is
permeated into the secondary battery, a side reaction occurs,
resulting in deterioration in performance of the secondary
25 battery and causing the generation of gas.
3
[0009] [Prior Art Document] (Patent Document) Korean Patent
Publication No. 10-2014-0015647
DISCLOSURE OF THE INVENTION
TECHNICAL PROBLEM
5 [0010] One aspect of the present invention is to provide a
secondary battery capable of discharging an internal gas while
minimizing moisture permeated from the outside.
TECHNICAL SOLUTION
[0011] A secondary battery according to an embodiment of the
10 present invention comprises an electrode assembly, in which
electrodes and separators are alternately stacked, a battery
case, in which an accommodation part accommodating the
electrode assembly is formed, and a sealing part is formed
along an outer circumferential surface thereof, a connection
15 pipe having one side connected to the accommodation part of
the battery case and the other side connected to the outside
of the battery case and passing through the battery case, and
an aroma valve connected to the other side of the connection
pipe 140 and disposed outside the battery case so as to be
20 opened to discharge an internal gas when an internal pressure
of the battery case is greater than or equal to a predetermined
pressure.
[0012] A battery pack according to an embodiment of the
present invention may comprise the secondary battery according
25 to an embodiment of the present invention.
4
ADVANTAGEOUS EFFECTS
[0013] According to the present invention, the aroma valve
may be connected through the connection pipe passing through
the sealing part of the battery case to discharge the internal
5 gas while minimizing the moisture permeated from the outside.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a plan view of a secondary battery according
to a first embodiment of the present invention.
[0015] FIG. 2 is a side view of the secondary battery
10 according to the first embodiment of the present invention.
[0016] FIG. 3 is a cross-sectional view taken along line BB’ of FIG. 1.
[0017] FIG. 4 is a perspective view of a connection pipe and
an aroma valve in the secondary battery according to the first
15 embodiment of the present invention.
[0018] FIG. 5 is a cross-sectional view of the secondary
battery according to the first embodiment of the present
invention.
[0019] FIG, 6 is a cross-sectional view of the aroma valve in
20 the secondary battery according to the first embodiment of the
present invention.

CLAIMS
1. A secondary battery comprising:
an electrode assembly, in which electrodes and separators
5 are alternately stacked;
a battery case, in which an accommodation part
accommodating the electrode assembly is formed, and a sealing
part is formed along an outer circumferential surface thereof;
a connection pipe having one side connected to the
10 accommodation part of the battery case and the other side
connected to the outside of the battery case and passing
through the battery case; and
an aroma valve connected to the other side of the
connection pipe and disposed outside the battery case so as to
15 be opened to discharge an internal gas when an internal
pressure of the battery case is greater than or equal to a
predetermined pressure.
2. The secondary battery of claim 1, wherein the
20 connection pipe comprises a polypropylene (PP) material.
3. The secondary battery of claim 2, wherein the
battery case comprises an upper case and a lower case,
each of surfaces facing each other on outer
25 circumferential surfaces of the upper case and the lower case
26
comprises a polypropylene (PP) material,
the connection pipe passes between the outer
circumferential surfaces of the upper case and the lower case,
and
5 an outer surface of the connection pipe is sealed
together with the outer circumferential surfaces of the upper
case and the lower case.
4. The secondary battery of claim 1, wherein the aroma
10 valve comprises:
a body having an exhaust hole formed therein;
a cover provided on an outer surface of the body to cover
the exhaust hole; and
an adhesive provided between the body and the cover to
15 allow the cover and the body to adhere to each other.
5. The secondary battery of claim 4, wherein the
adhesive comprises silicone oil.
20 6. The secondary battery of claim 1, wherein the aroma
valve comprises:
a body having an exhaust hole formed therein;
a cover provided on an outer surface of the body to cover
the exhaust hole; and
25 an elastic member configured to surround the cover,
27
wherein the elastic member has an end fixed to the body and
fixes the cover to the body by elastic force thereof.
7. The secondary battery of claim 6, wherein, when the
5 internal pressure of the battery case is equal to or greater
than the elastic force of the elastic member, the cover and
the body are spaced apart from each other so that the exhaust
hole is opened to discharge the internal gas, and
when the internal pressure of the battery case is lowered
10 after discharging the internal gas, the cover and the body are
in close contact with each other by restoring force of the
elastic member so that the exhaust hole is sealed.
8. The secondary battery of claim 6, wherein the
15 elastic member is made of a material comprising at least one
or more of natural rubber, a poly-isoprene-based material,
polyvinylidene fluoride (PVDF) (polyproplylene), polyvinyl
fluoride (PVF), poly-3-hydroxybutrate (PHB), polyvinyl acetate
(PVA), polychlorotrifluoroethylene (PCTFE), polyamide,
20 polyactic acid, polyethylene terephthalate, polyvinylchloride,
polyvinyl alcohol, polystyrene, poly methyl methacrylate
(PMMA), polytetrafluoroethlene (PTFE), poly carbonate,
polysulfone, and polynorbone.