Electrode assembly for secondary battery including separator with notch groove and secondary battery comprising the same
According to embodiments of the present disclosure, there is provided an electrode assembly for secondary battery comprising: a stacked body that includes a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, with the separator being located at the outermost surface on both sides; and at least two pairs of fixing members attached in the stacking direction for fixing between the separators located at the outermost surface on both sides of the stacked body, wherein the separator includes at least one pair of notch grooves, and wherein the pair of notch grooves are formed one by one on one surface perpendicular to a protruding direction of an electrode tab and the other surface located in a diagonal direction thereof.
1 . An electrode assembly for a secondary battery, the electrode assembly comprising:
a stacked body that includes a first outermost surface, a second outermost surface opposite the first outermost surface, a positive electrode, a negative electrode, and a plurality of separators stacked with one another, the plurality of separators including first and second separators located at the first and second outermost surfaces, respectively;
wherein each of the first and second separators comprise a first longitudinal side and a second longitudinal side;
and at least two pairs of fixing members extending in a stacking direction between the first and second separators and located at the first longitudinal side and the second longitudinal sides of the first and second separators,
wherein each of the first and second separators includes at least one pair of notch grooves,
wherein a first groove of a first pair of notch grooves of the first separator extends into a first lateral edge of the first separator, the first lateral edge of the first separator is perpendicular to the first longitudinal side of the first separator; and
a first groove of a first pair of notch grooves of the second separator extends into a first lateral edge of the second separator, the first lateral edge of the second separator is perpendicular to the first longitudinal side of the second separator; and
a second groove of the first pair of notch grooves of the first separator extends into a second lateral edge of the first separator, the second lateral edge of the first separator is opposite to the first lateral edge of the first separator and perpendicular to the second longitudinal side of the first separator; and
a second groove of the first pair of notch grooves of the second separator extends into a second lateral edge of the second separator, the second lateral edge of the second separator is opposite to the first lateral edge of the second separator and perpendicular to the second longitudinal side of the second separator;
and wherein a first electrode tab protrudes along a first lateral edge of the stacked body and a second electrode tab protrudes along a second lateral edge of the stacked body,
and wherein, in the stacking direction, the first groove of the first pair of notch grooves of the first separator is located between the first electrode tab and a corner of the first separator formed from the first longitudinal side of the first separator and the first lateral edge of the first separator; and
in the stacking direction, the first groove of the first pair of notch grooves of the second separator is located between the first electrode tab and a corner of the second separator formed from the first longitudinal side of the second separator and the first lateral edge of the second separator; and
in the stacking direction, the second groove of the first pair of notch grooves of the first separator is located between the second electrode tab and a corner of the first separator formed from the second longitudinal side of the first separator and the second lateral edge of the first separator; and
in the stacking direction, the second groove of the first pair of notch grooves of the second separator is located between the second electrode tab and a corner of the second separator formed from the second longitudinal side of the second separator and the second lateral edge of the second separator; and
wherein the first and second separators are configured such that when the first and second separators are contracted, tearing of the first and second separators occurs while inducing a path in which the first and second separators are contracted by the at least one pair of notch grooves.
2 . The electrode assembly according to claim 1 , wherein the at least one pair of notch grooves is at least two pairs of notch grooves,
wherein a first groove of a second pair of notch grooves of the first separator extends into the first lateral edge of the first separator; a first groove of a second pair of notch grooves of the second separator extends into the first lateral edge of the second separator; and
wherein a second groove of the second pair of notch grooves of the first separator extends into the second lateral edge of the first separator; and a second groove of the second pair of notch grooves of the second separator extends into the second lateral edge of the second separator; and
wherein, in the stacking direction, the first groove of the second pair of notch grooves of the first separator is located between the first electrode tab and a corner of the first separator formed from the second longitudinal side of the first separator and the first lateral edge of the first separator; and
wherein, in the stacking direction, the first groove of the second pair of notch grooves of the second separator is located between the first electrode tab and a corner of the second separator formed from the second longitudinal side of the second separator and the first lateral edge of the second separator; and
wherein, in the stacking direction, the second groove of the second pair of notch grooves of the first separator is located between second electrode tab and a corner of the first separator formed from the second lateral edge of the first separator and the first longitudinal side of the first separator; and
wherein, in the stacking direction, the second groove of the second pair of notch grooves of the second separator is located between second electrode tab and a corner of the second separator formed from the second lateral edge of the second separator and the first longitudinal side of the second separator.
3 . The electrode assembly according to claim 1 , wherein each notch groove is formed at a position that does not overlap the first electrode tab or the second electrode tab.
4 . The electrode assembly according to claim 1 , wherein a planar shape of each notch groove is a slit-like shape, a polygonal shape, a circular shape, or an elliptical shape.
5 . The electrode assembly according to claim 4 , wherein the planar shape of each notch groove is a slit-like shape or a triangular shape.
6 . The electrode assembly according to claim 1 , wherein each fixing member includes polyimide.
7 . The electrode assembly according to claim 1 , wherein a first pair of the at least two pairs of fixing members are disposed at positions of the first and second longitudinal sides of the first and second separators, and a second pair of the at least two pairs of fixing members are disposed at positions of the first and second longitudinal sides of the first and second separators, the first pair of fixing members being spaced apart from the second pair of fixing members.
8 . The electrode assembly according to claim 1 , wherein the electrode assembly is a lamination and stack type electrode assembly or a stack and folding type electrode assembly.
9 . The secondary battery comprising the electrode assembly according to claim 1 disposed in a secondary battery case together with an electrolyte.