Patent Description:
Demand for a secondary battery as an energy source for mobile devices, electric vehicles, etc. has abruptly increased. In particular, demand for a lithium secondary battery, which has high energy density and high discharge voltage, is high.

Based on the shape and material thereof, the lithium secondary battery may be classified as a cylindrical secondary battery made of a metal material, a prismatic secondary battery made of a metal material, or a pouch-shaped battery made of a laminate sheet. The pouch-shaped battery has advantages in that the pouch-shaped secondary battery is stacked with high degree of integration, thereby having high energy density per unit weight, is manufactured at low cost, and is easily deformable. Consequently, the pouch-shaped battery is used in various devices.

In general, a laminate sheet including an outer coating layer, a metal blocking layer, and an inner adhesive layer is shaped so as to be used as a battery case of the pouch-shaped battery. An electrode assembly is received in a receiving portion formed in the laminate sheet together with an electrolytic solution, and the receiving portion is sealed, whereby the pouch-shaped battery is manufactured.

As shown in <FIG>, a pouch-shaped battery <NUM> is configured such that an electrode assembly <NUM> is mounted in a receiving portion <NUM> of a battery case <NUM> constituted by a pouch-shaped lower part <NUM> and a pouch-shaped upper part <NUM>. In the electrode assembly <NUM>, positive and negative electrode tabs <NUM> and <NUM> are exposed outside of the battery case <NUM> in a state of being welded respectively to two electrode leads <NUM> and <NUM>. An outer periphery of the battery case <NUM> is sealed in the state in which a pair of insulative films <NUM> and a pair of insulative films <NUM> are disposed respectively at an upper part and a lower part of the electrode lead <NUM> and an upper part and a lower part of the electrode lead <NUM>.

The outer periphery of the battery case <NUM> is sealed as the result of inner adhesive layers of laminate sheets being thermally melted and pressed by a rectangular parallelepiped sealing tool that is long in a longitudinal direction thereof.

<FIG> is an exploded perspective view of a pouch-shaped battery case sealing apparatus <NUM> according to Patent Document <NUM>. An outer periphery of a pouch-shaped battery is disposed between a holder <NUM> and a sealing block <NUM>. The holder <NUM>, which is movable upwards and downwards by a lifting means <NUM>, is moved downwards, and the outer periphery of the pouch-shaped battery is heated and fused, whereby the outer periphery of the pouch-shaped battery is sealed. The holder <NUM> and the lifting means <NUM> are fixed or are tiltable only in one direction.

Conventionally, the holder <NUM> and the lifting means <NUM> are fixed. In recent years, demand for secondary batteries has rapidly increased, and therefore various attempts to reduce process time for each step have been made. Conventionally, the holder <NUM> fixed to the lifting means <NUM> sufficiently presses an outer periphery of a laminate sheet to seal the outer periphery of the laminate sheet. An attempt to change the structure of the holder so as to be tiltable in a direction toward the sealing block <NUM> in order to rapidly and uniformly performing pressing has been made. Since tilting is performed only in one direction, however, a pouch-shaped secondary battery defect rate is not reduced, and yield is also lowered.

Patent Document <NUM> relates to a battery cell having a welded surplus portion, the battery cell including an electrode assembly having a structure including a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode; and a battery case having a structure including a sealed surplus portion at which an outer periphery of the battery case is sealed in the state in which the electrode assembly is received in the battery case, wherein the battery case is made of a laminate sheet having a structure in which a first resin layer, a metal layer, and a second resin layer are sequentially stacked from the side facing the electrode assembly, the sealed surplus portion is configured to have a structure in which a first sheet portion and a second sheet portion of the laminate sheet that face each other are joined to each other, at least a part of the sealed surplus portion includes a resin layer fusion portion formed by the first resin layer of the first sheet portion and the first resin layer of the second sheet portion and a metal layer weld portion formed by an end of the metal layer of the first sheet portion and an end of the metal layer of the second sheet portion.

Patent Document <NUM> discloses that first and second sealing tools are disposed above and under the sheet portion and that the sealing tools are rotated so as to be inclined by a predetermined angle; however, the sealing tools are configured to be tilted only in one direction, as mentioned above. Furthermore, Patent Document <NUM> discloses a means configured to further press a part of the portion to be sealed, not the entire portion to be sealed, which cannot become a solution for uniformly sealing the entire portion to be sealed, which is achieved by the present invention.

Patent Document <NUM> relates to a sealing apparatus used to seal a secondary battery packaging material, the sealing apparatus including a first sealing tool, a second sealing tool configured to perform sealing while facing the first sealing tool, a first pulling unit attached to an end of the first sealing tool, and a second pulling unit attached to an end of the second sealing tool so as to correspond to the first pulling unit, wherein, in a sealing process, the first pulling unit pulls the end of the first sealing tool in a direction toward the second sealing tool, and the second pulling unit pulls the end of the second sealing tool in a direction toward the first sealing tool.

Patent Document <NUM> relates to an apparatus for bending a sealed surplus portion formed at an outer periphery of an electrode assembly receiving portion of a battery cell in a direction toward the electrode assembly receiving portion, the apparatus including a cell fixing jig to which the battery cell is mounted in the state in which an outer end of the sealed surplus portion protrudes outwards from an outer side of the jig; a guide member configured to press an inner end of the sealed surplus portion that abuts the electrode assembly receiving portion downwards in a first direction perpendicular to the ground to form a bent point; and a bending member configured to press the outer end of the sealed surplus portion upwards while moving in a second direction opposite the first direction such that the outer end of the sealed surplus portion is bent in the second direction based on the bent point; wherein, in the state in which the outer end of the sealed surplus portion is bent in the second direction, the guide member returns to the position thereof before pressing, and the bending member is rotated in a third direction perpendicular to the first direction and the second direction to further bend the outer end of the sealed surplus portion in the third direction.

Patent Document <NUM> relates to a power storage device and a package structure thereof, wherein a power storage device cell configured such that bottoms of electrode terminals <NUM> and <NUM> are fixed to an adaptor <NUM> is received in two frames <NUM>, which are coupled to each other, the adapter <NUM> is pressed and held by the frames <NUM>, a power storage unit <NUM> is floated with respect to the frames <NUM> using the adaptor <NUM> as a supporting point, whereby the power storage device cell is positioned by the frames <NUM>, and therefore it is possible to easily handle the power storage device cell.

Patent Documents <NUM> to <NUM> do not disclose a construction for freely moving the sealing tool, and therefore do not recognize a problem to be solved by the present invention. <CIT> discloses a pressing apparatus for sealing a battery in a film pouch.

In sealing of a pouch-shaped battery recognized by the present invention as an important problem, as described above, technology capable of uniformly sealing a surface to be sealed within a short time, thereby improving sealing efficiency, has not yet been proposed.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a pouch-shaped battery case sealing apparatus capable of uniformly sealing a portion to be sealed of an outer periphery of a pouch-shaped secondary battery, thereby improving sealing efficiency while reducing sealing time, and a pouch-shaped secondary battery sealing method using the same.

In order to accomplish the above object, the present invention provides a pouch-shaped battery case sealing apparatus including an upper sealing block and a lower sealing block, wherein a surface to be sealed of the pouch-shaped battery case is disposed in an X-Y plane, the upper sealing block and the lower sealing block are configured to be disposed in parallel to a Y-axis, the upper sealing block is fixed to a fixing shaft configured to move upwards and downwards along a Z-axis direction so as to be moved upwards and downwards along a Z-axis direction, and the upper sealing block and the fixing shaft are coupled to each other via a hip joint type coupling unit.

The coupling unit may be disposed at the middle of the upper sealing block, and the upper sealing block may perform tilting motion with respect to the X-Y plane about the Z-axis. Meanwhile, a guide configured to prevent rotational motion of the upper sealing block about the Z-axis may be formed in the vicinity of the upper sealing block.

The coupling unit may include a first insertion portion extending from the fixing shaft, the distal end of the first insertion portion being spherical, and a first support portion fixed to the upper sealing block, the first insertion portion being inserted into and fixed to the first support portion.

The coupling unit may include a second insertion portion extending from the upper sealing block, the distal end of the second insertion portion being spherical; and a second support portion disposed at the distal end of the fixing shaft, the second insertion portion being inserted into and fixed to the second support portion.

The fixing shaft may move about the coupling unit in the form of precession with respect to the Z-axis.

In one embodiment not falling within the scope of the present claims, the hip joint type coupling unit may be replaced with a coupling unit having two or more joints.

In another aspect, the present invention provides a method of sealing a pouch-shaped battery using the pouch-shaped battery case sealing apparatus.

Further, the present application describes a pouch-shaped battery sealed using the pouch-shaped battery case sealing apparatus.

As is apparent from the above description, the present invention may provide a pouch-shaped battery case sealing apparatus capable of uniformly sealing a portion to be sealed of an outer periphery of a pouch-shaped secondary battery, thereby improving sealing efficiency while reducing sealing time, and a pouch-shaped secondary battery sealing method using the same.

The sealing apparatus according to the present invention is capable of securing a uniformly sealed surface within a short time while reducing a sealing defect rate.

<FIG> is a schematic view of a conventional pouch-shaped battery case sealing apparatus <NUM> configured to perform tilting motion about only one axis.

The pouch-shaped battery case sealing apparatus <NUM> includes an upper sealing block <NUM> and a lower sealing block <NUM>. In a pouch-shaped battery case sealing apparatus <NUM> or <NUM> according to the present invention as well as the conventional pouch-shaped battery case sealing apparatus <NUM>, an outer periphery of a pouch-shaped battery case to be sealed is located between the upper sealing block <NUM>, <NUM>, or <NUM> and the lower sealing block <NUM>, <NUM>, or <NUM>, in the same manner.

In addition, a surface to be sealed of the pouch-shaped battery case is disposed in an X-Y plane, the upper sealing block <NUM>, <NUM>, or <NUM> and the lower sealing block <NUM>, <NUM>, or <NUM> are disposed in parallel to a Y-axis, the upper sealing block <NUM>, <NUM>, or <NUM> is fixed to a fixing shaft <NUM>, <NUM>, or <NUM> configured to move upwards and downwards in a Z-axis direction so as to be moved upwards and downwards in a Z-axis direction, and the upper sealing block <NUM>, <NUM>, or <NUM> and the fixing shaft <NUM>, <NUM>, or <NUM> are coupled to each other via a coupling unit <NUM>, <NUM>, or <NUM>.

In the conventional pouch-shaped battery case sealing apparatus <NUM>, the coupling unit <NUM> is configured to perform one-axis coupling. Consequently, the upper sealing block <NUM> performs only rotational motion in a plane parallel to a Y-Z plane about the center of the coupling unit <NUM>. The rotational motion may also be referred to as spin motion about an X-axis.

In contrast, in the pouch-shaped battery case sealing apparatus <NUM> or <NUM> according to the first embodiment or the second embodiment of the present invention, coupling is achieved through a hip joint type coupling unit <NUM> or <NUM>.

The coupling unit <NUM> or <NUM> may be disposed at the middle of the upper sealing block <NUM> or <NUM>, and the upper sealing block <NUM> or <NUM> may perform tilting motion with respect to the X-Y plane about the Z-axis, specifically about the coupling unit <NUM> or <NUM>. Rotational motion about the Z-axis is not desirable while the tilting motion is performed. Consequently, a guide (not shown) may be formed in the vicinity of the upper sealing block <NUM> or <NUM> in order to prevent rotational motion of the upper sealing block about the Z-axis.

The upper sealing block <NUM> or <NUM> may perform spin motion about the X-axis and spin motion about the Y-axis. Consequently, the pouch-shaped battery case sealing apparatus according to the present invention is capable of more efficiently performing sealing than the conventional apparatuses <NUM> and <NUM>, whereby it is possible to reduce process time.

The coupling unit <NUM> may include a first insertion portion <NUM> extending from the fixing shaft <NUM>, the distal end of the first insertion portion <NUM> being spherical; and a first support portion <NUM> fixed to the upper sealing block <NUM>, the first insertion portion <NUM> being inserted into and fixed to the first support portion <NUM>. In <FIG>, A is an enlarged view of the first insertion portion <NUM> and the first support portion <NUM>. The first insertion portion <NUM> and the first support portion <NUM> may be coupled to each other by interference fitting, and a separate lubricant may be added therebetween.

The coupling unit <NUM> may include a second insertion portion <NUM> extending from the upper sealing block <NUM>, the distal end of the second insertion portion <NUM> being spherical; and a second support portion <NUM> disposed at the distal end of the fixing shaft <NUM>, the second insertion portion <NUM> being inserted into and fixed to the second support portion <NUM>. In <FIG>, B is an enlarged view of the second insertion portion <NUM> and the second support portion <NUM>. The second insertion portion <NUM> and the second support portion <NUM> may be coupled to each other by interference fitting, and a separate lubricant may be added therebetween.

Meanwhile, the fixing shaft <NUM> or <NUM> may move about the coupling unit <NUM> or <NUM> in the form of precession with respect to the Z-axis. This motion is performed in order to further press the upper sealing block <NUM> or <NUM> in a direction tilted from the lower sealing block <NUM> or <NUM>. On the assumption that the central axis of the fixing shaft <NUM> or <NUM> when inclined from the Z-axis by an angle t for precession is R, R may perform precession along an upper circle. Upward and downward movement, tilting, and precession related to driving of an upper end of the fixing shaft <NUM> or <NUM> are not specifically defined, and are not shown in the figure. This construction may be selected by those skilled in the art as needed.

In an embodiment not according to the present invention, the hip joint type coupling unit <NUM> or <NUM> may be replaced with a coupling unit <NUM> having two or more joints. A representative example of the coupling unit having two or more joints is shown in <FIG>. In <FIG>, C and C' are portions respectively coupled to the upper sealing block and the fixing shaft or to the fixing shaft and the upper sealing block.

In another aspect, the present invention provides a method of sealing a pouch-shaped battery using the pouch-shaped battery case sealing apparatus. In a further aspect, the present invention provides a pouch-shaped battery sealed using the pouch-shaped battery case sealing apparatus.

Those skilled in the art to which the present invention pertains will appreciate that various applications and modifications are possible within the category of the present invention based on the above description.

Claim 1:
A pouch-shaped battery case sealing apparatus (<NUM>, <NUM>), comprising:
an upper sealing block (<NUM>, <NUM>) and a lower sealing block (<NUM>, <NUM>),
wherein a surface to be sealed of the pouch-shaped battery case is disposed in an X-Y plane,
the upper sealing block (<NUM>, <NUM>) and the lower sealing block (<NUM>, <NUM>) are configured to be disposed in parallel to a Y-axis,
the upper sealing block (<NUM>, <NUM>) is fixed to a fixing shaft (<NUM>, <NUM>) configured to move upwards and downwards along a Z-axis direction so as to be moved upwards and downwards along the Z-axis direction, characterized in that
the upper sealing block (<NUM>, <NUM>) and the fixing shaft (<NUM>, <NUM>) are coupled to each other via a hip joint type coupling unit (<NUM>, <NUM>).