Patent Description:
Secondary batteries may be classified into a cylindrical battery, a prismatic battery, and a pouch-shaped battery based on the shape thereof. Among these batteries, the pouch-shaped battery, which can be stacked with high integration, has high energy density per unit weight, and can be easily deformed, has attracted considerable attention.

The pouch-shaped battery, which means a battery configured such that a battery case is made of a laminate sheet, has a structure in which an electrode assembly is mounted in the battery case. <FIG> is a schematic view of a pouch-shaped battery <NUM>, wherein the pouch-shaped battery <NUM> has an electrode assembly <NUM> mounted in a battery case <NUM>, the electrode assembly including a positive electrode, a negative electrode, and a separator disposed therebetween. Positive electrode and negative electrode tabs of the electrode assembly <NUM> are welded to two electrode leads, respectively, and the battery case is hermetically sealed in the state in which the electrode leads are exposed outwards from the battery case.

The battery case <NUM> is made of a laminate sheet, and includes a concave receiving portion <NUM>, in which the electrode assembly <NUM> is seated. An upper case <NUM> corresponds to a lower case <NUM>, and hermetically seals the receiving portion <NUM>, in which the electrode assembly <NUM> is received. The receiving portion <NUM> is manufactured by pressing and deforming the laminate sheet using a punch having a shape corresponding to the shape of the receiving portion.

<FIG> is a photograph showing wrinkles formed at a corner part of the receiving portion of the pouch-shaped battery. Referring to <FIG>, when the receiving portion <NUM> is shaped by pressing of the punch, wrinkles may be generated at a corner part A of the electrode assembly receiving portion <NUM>. The wrinkles cause a substantial problem in that the pouch-shaped battery is easily damaged during manufacture or use of the pouch-shaped battery as well as an aesthetical problem.

Patent Document <NUM> discloses a pouch shaping apparatus and a shaping method capable of gradually reducing pressing force of a stripper configured to fix a laminate sheet, whereby it is possible to gradually increase elongation of the laminate sheet, and therefore it is possible to prevent generation of cracks at an angular point of a receiving portion.

In Patent Document <NUM>, the pouch shaping apparatus includes a punch, a stripper member including a stripper configured to press a laminate sheet disposed on a support so as to be fixed and a first driving piece configured to move the stripper in an upward-downward direction, and a control member configured to, when the punch presses the laminate sheet while being inserted in a shaping portion of the support, control the first driving piece such that the stripper is moved upwards, thereby reducing pressing force applied to the laminate sheet. In Patent Document <NUM>, the control member, which controls the stripper driving piece configured to move the stripper upwards when the punch is moved downwards to press the laminate sheet, is added, whereby the structure of the pouch shaping apparatus is complicated.

Patent Document <NUM> discloses a pouch shaping apparatus that uniformly disperses stretching force applied to a pouch film when a cup part of a pouch is formed, thereby preventing generation of wrinkles at the cup part. In Patent Document <NUM>, a blanking holder is located at a central part of the support so as to be movable upwards and downwards, the blanking holder contacts one surface of the laminate sheet disposed at an upper end of the support, and the blanking holder is moved downwards together with the punch that is moved downwards from an upper end of the laminate sheet after contact with the laminate sheet disposed at the upper end of the support, whereby the cup part is formed.

In Patent Documents <NUM> and <NUM>, formation of wrinkles at a corner part of a pouch case is prevented; however, the construction of the apparatus is more complicated than conventional pouch shaping apparatuses, and a pouch shaping process is complicated.

The relevant prior art for the present invention are given by <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT> and <CIT>.

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 shaping apparatus capable of, when pressing a laminate sheet to form a receiving portion configured to receive an electrode assembly, reducing or preventing generation of wrinkles at a corner of the receiving portion and a pouch with remedied wrinkles manufactured thereby.

A pouch shaping apparatus according to the present invention to accomplish the above object includes a support unit configured to allow a laminate sheet to be disposed on an upper surface thereof, a stripper located above the support unit, the stripper configured to be movable upwards and downwards, the stripper configured to press and fix an outer periphery of the laminate sheet disposed on the upper surface of the support unit when moved downwards, and a punch located above the support unit, the punch configured to be movable upwards and downwards, the punch configured to form an electrode assembly receiving portion in the laminate sheet while inserted into a shaping portion located at the center of the support unit when moved downwards, wherein the support unit includes an upper support and a support plate, and the pouch shaping apparatus includes a core member located between the upper support and the support plate, the core member having a predetermined thickness.

The upper support may include a shaping portion, as an empty space defined therein, the shaping portion configured to allow the punch to be inserted thereinto such that the electrode assembly receiving portion is formed in the laminate sheet, and an upper support frame constituting a periphery of the shaping portion.

The core member comprises a plurality of core members, the plurality of core members disposed spaced apart from each other.

The core members are disposed at a lower end of the upper support frame adjacent to corner parts of the shaping portion.

The core members may be disposed at positions symmetrical with respect to the center of the upper support frame.

The core member may comprise, on at least one surface thereof, an adhesive layer, and the core member may be detachably attached to an upper surface of the support plate and/or a lower surface of the upper support frame.

A pressing surface of the stripper that faces the laminate sheet may face an upper surface of the upper support frame, and the stripper may include a second stripper added to the pressing surface and a first stripper disposed at a lower surface of the second stripper.

The second stripper may include an elastic material.

Bead portions may be disposed so as to correspond to each other at a pressing surface of the stripper that faces an upper surface of the laminate sheet and an upper surface of the upper support frame that faces a lower surface of the laminate sheet.

The bead portions may comprise a plurality of bead portions, the plurality of bead portions disposed spaced apart from each other.

The bead portions may be disposed at positions adjacent to corner parts of the shaping portion.

Each of the bead portions may be formed in a straight shape and may be located so as to have an oblique angle with respect to two sides that join each other at a right angle of the upper support frame constituting the shaping portion.

In addition, the present invention provides a pouch manufactured using the pouch shaping apparatus and a pouch-shaped battery comprising the pouch.

As is apparent from the above description, a pouch shaping apparatus according to the present invention has an effect in that a core member is added, whereby it is possible to reduce or prevent generation of wrinkles at a corner part of a pouch receiving portion while minimizing an increase in construction and volume.

In addition, the pouch shaping apparatus according to the present invention has an advantage in that it is possible to easily replace an upper support based on the size of a battery.

In addition, all numeric ranges include the lowest value, the highest value, and all intermediate values therebetween unless the context clearly indicates otherwise.

Embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<FIG> is a front view of a pouch shaping apparatus according to a first embodiment of the present invention, <FIG> is a perspective view of a support unit of the pouch shaping apparatus according to the first embodiment of the present invention, and <FIG> is an exploded perspective view of <FIG>.

Referring to <FIG>, the pouch shaping apparatus <NUM> according to the first embodiment of the present invention includes a support unit <NUM> configured to allow a laminate sheet <NUM> to be disposed on an upper surface thereof, a stripper <NUM> located above the support unit <NUM>, the stripper being configured to be movable upwards and downwards, the stripper being configured to press and fix an outer periphery of the laminate sheet <NUM> disposed on the upper surface of the support unit <NUM> when being moved downwards, and a punch <NUM> located above the support unit <NUM>, the punch being configured to be movable upwards and downwards, the punch being configured to form an electrode assembly receiving portion in the laminate sheet <NUM> while being inserted into a shaping portion <NUM> located at the center of the support unit <NUM> when being moved downwards. Although not shown in the drawings, the pouch shaping apparatus <NUM> may include a controller and a driving unit configured to move the punch <NUM> and the stripper <NUM> upwards and downwards.

The punch <NUM> according to the first embodiment of the present invention is located above the support unit <NUM>, is configured to be movable upwards and downwards, and forms the electrode assembly receiving portion in the laminate sheet <NUM> while being inserted into the shaping portion <NUM> located at the center of the support unit <NUM> when being moved downwards. Although not shown in the drawings, a punch controller and a punch driving unit configured to move the punch <NUM> upwards and downwards may be included. When the punch driving unit is driven, the punch <NUM> presses the laminate sheet <NUM> located at an upper end of the support unit <NUM> so as to be inserted into the shaping portion <NUM> while being moved downwards, whereby the electrode assembly receiving portion is formed in the laminate sheet <NUM>.

The stripper <NUM> according to the first embodiment of the present invention, which is provided to fix the laminate sheet <NUM> disposed on the uppermost surface of the support unit <NUM>, is located above the support unit <NUM>, and is configured to be movable upwards and downwards. Although not shown in the drawings, a stripper controller and a stripper driving unit configured to move the stripper <NUM> upwards and downwards may be included. The stripper <NUM> has a size corresponding to the size of an upper surface of an upper support <NUM>, and a hole (not shown), through which the punch <NUM> can extend, is formed in a central part of the stripper.

The support unit <NUM> includes an upper support <NUM> and a support plate <NUM>. Here, the area of the upper support <NUM> may be equal to or less than the area of the support plate <NUM> such that an outer periphery of the upper support <NUM> does not extend farther than an outer periphery of the support plate <NUM>.

The upper support <NUM> includes a shaping portion <NUM>, which is an empty space defined therein, the shaping portion being configured to allow the punch <NUM> to be inserted thereinto such that the electrode assembly receiving portion is formed in the laminate sheet <NUM>, and an upper support frame <NUM> constituting a periphery of the shaping portion <NUM>.

The shaping portion <NUM> is located in the upper support frame <NUM>, and is formed through the upper support <NUM> from an upper surface to a lower surface thereof in order to form the electrode assembly receiving portion. The shaping portion <NUM> is configured to have a size corresponding to the size of the hole of the stripper <NUM>, and the punch <NUM> may be inserted up into the shaping portion <NUM> through the hole of the stripper <NUM>.

The support plate <NUM> is located at a lower surface of the upper support frame <NUM>.

A plurality of core members <NUM> is disposed so as to be spaced apart from each other between facing surfaces of the support plate <NUM> and the upper support frame <NUM>. Specifically, four core members <NUM> are located at parts adjacent to four corner parts B of the shaping portion <NUM> in one-to-one correspondence.

The core members <NUM> are located between the upper support <NUM> and the support plate <NUM>, and it may be seen that the core members are disposed at a lower end of the upper support frame <NUM> adjacent to the corner parts B of the shaping portion <NUM>.

Each of the core members <NUM> may be formed in an "L" shape corresponding to two sides that join each other at a right angle of the upper support frame <NUM> that forms the corner parts B of the shaping portion <NUM>. That is, each core member may be constituted by one long side and one short side that are coupled perpendicular to each other so as to form an "L" shape.

The core members <NUM> are disposed at positions symmetrical with respect to the center of the upper support frame <NUM>. That is, the "L"-shaped core members may be disposed at the lower end of the upper support frame adjacent to the corner parts B in symmetry. Diagonal symmetry, horizontal symmetry, and vertical symmetry are possible as symmetry. Although each core member <NUM> is shown as having an "L" shape in the drawings, each core member may be configured to have an "I" shape.

Since each core member <NUM> has a predetermined thickness, the upper support <NUM> and the support plate <NUM> are spaced apart from each other by the core members <NUM>.

When the punch <NUM> is moved downwards to press the laminate sheet <NUM> located on the support unit <NUM> so as to be inserted into the shaping portion <NUM>, the upper support frame <NUM> cannot move downwards in a z-axis direction due to the core members <NUM> at the corner parts B of the shaping portion at which the core members <NUM> are located, but the upper support frame <NUM> is deformed in the z-axis direction with increasing distance from the core members <NUM>, whereby the downward movement distance of the upper support frame is increased.

Since the movement distance of the upper support frame <NUM> at a middle part of each of sides thereof in an overall length direction is greater than the movement distance of the upper support frame at each of the corner parts, the z-axis downward movement distance of the upper support frame <NUM> is the maximum at the middle part of each of the sides thereof in the overall length direction. The laminate sheet <NUM> interposed between the punch <NUM> and the upper support frame <NUM> is minimally stretched at the middle part of each of the sides of the upper support frame <NUM> in the overall length direction. As a result, when the laminate sheet is pressed by the punch, tensile force is generated at the central part of the laminate sheet in the overall length direction, which is the minimally stretched portion, toward the corner parts B.

When the laminate sheet is pressed by the punch to shape a pouch, at corner parts of a receiving portion of the pouch, radial tensile force acting in a depth direction of the receiving portion and circumferential compressive force concentrated from sealed surfaces of the corner parts to the corner parts are generated. As shown in <FIG>, wrinkles are generated at each of the corner parts of the pouch by the radial tensile force and the circumferential compressive force.

When the core members <NUM> are disposed between the upper support <NUM> and the support plate <NUM>, as in the present invention, additional tensile force is generated at each of the corner parts of the laminate sheet, when the laminate sheet is pressed by the punch, whereby the radial tensile force concentrated on the corner parts B of the shaping portion <NUM> is reduced, and therefore, it is possible to reduce generation of wrinkles at the corner parts of the receiving portion.

The core members <NUM> may have uniform thickness. The thickness of each of the core members <NUM> may range from <NUM> to <NUM>, specifically from <NUM> to <NUM>. If the thickness of each of the core members <NUM> is less than <NUM>, when the laminate sheet <NUM> is pressed by the punch <NUM>, whereby the laminate sheet is inserted into the shaping portion <NUM> to form the electrode assembly receiving portion, it is difficult to prevent generation of wrinkles at the corner parts of the electrode assembly receiving portion, since the downward movement distance of the upper support frame <NUM> in the z-axis direction is too short. If the thickness of each of the core members is greater than <NUM>, the laminate sheet <NUM> may be excessively stretched at the center of the shaping portion <NUM> in the downward direction (z-axis direction), whereby the laminate sheet may rupture.

The thickness of each core member <NUM> may be changed based on the following criterion in consideration of the thickness of the laminate sheet.

When the long side and the short side of each core member <NUM> join each other at a right angle so as to be formed in an "L" shape, the thickness of the core member may range from <NUM> to <NUM>, the length of the long side of each core member may range <NUM> to <NUM>, and the length of each short side of the core member may range <NUM> to <NUM>. In addition, each core member <NUM> may be formed in an "I" shape having a thickness of <NUM> to <NUM> and a length of <NUM> to <NUM>. If the lengths of each core member are less than the minimum value of the length, it is difficult to prevent formation of wrinkles at the corner parts of the receiving portion when the laminate sheet <NUM> is shaped. If the lengths of each core member are greater than the maximum value of the length, cracks may be generated when the receiving portion is formed.

In the present invention, each core member <NUM> may be made of the same material as the upper support <NUM> and the support plate <NUM>. In addition, each core member <NUM> may be made of a material that exhibits high rigidity and elasticity. This is advantageous to preventing breakage of each core member <NUM> due to pressure repeatedly applied thereto when the stripper <NUM> is moved downwards to press and fix the laminate sheet <NUM> located at the upper end of the upper support <NUM> or absorbing stress applied to the upper support <NUM> and the support plate <NUM> located above and under the core members to prevent damage to the upper support <NUM> and the support plate <NUM>.

In the present invention, at least one of an upper surface of each core member <NUM> that faces the upper support <NUM> and a lower surface of each core member <NUM> that faces the support plate <NUM> may include an adhesive layer (not shown). For example, each core member <NUM> may be detachably attached to an upper surface of the support plate <NUM> and/or a lower surface of the upper support frame <NUM>. When the upper support <NUM> is changed so as to correspond to various sizes of pouch-shaped battery cases, the position of each core member <NUM> on the upper surface of the support plate <NUM> may be changed based on the size of the upper support <NUM>, and each core member <NUM> may be fixed using the adhesive layer.

In another example, a recess, into which a part of each core member <NUM> is inserted, may be provided in each of the lower surface of the upper support frame <NUM> and the upper surface of the support plate <NUM> such that the upper support frame <NUM> and the support plate <NUM> are not moved when the laminate sheet <NUM> is shaped.

The upper support <NUM> and the support plate <NUM> may be coupled and fixed to each other via a coupling member configured to be easily detached and attached.

<FIG> is a perspective view of a two-stage stripper according to a second embodiment of the present invention.

Referring to <FIG>, a two-stage stripper <NUM> of a pouch shaping apparatus according to a second embodiment includes a first stripper <NUM> and a second stripper <NUM>, wherein the first stripper corresponds to the stripper of the pouch shaping apparatus according to the first embodiment, and it is understood that the pouch shaping apparatus according to the second embodiment is configured to have a structure in which the second stripper is added to the pouch shaping apparatus according to the first embodiment. Hereinafter, therefore, only the two-stage stripper <NUM> will be described. A description of the stripper of the pouch shaping apparatus according to the first embodiment may be equally applied to the first stripper, and therefore only the two-stage stripper will be described hereinafter.

The two-stage stripper <NUM> according to the second embodiment includes a first stripper <NUM> and a second stripper <NUM>. As shown in <FIG>, the second stripper <NUM> is located spaced apart from a hole of the first stripper <NUM> by a predetermined distance.

The second stripper <NUM> is added to a pressing surface of the stripper that faces the laminate sheet. Specifically, the second stripper <NUM> faces the upper support <NUM> while being located at a lower surface of the first stripper <NUM>. Here, the second stripper <NUM> may have predetermined adhesiveness and/or may include an elastic material. Alternatively, the second stripper may be constituted by a coating layer including an elastic material. Consequently, the second stripper <NUM> may increase fixing force of the laminate sheet located at the upper end of the support unit and may control the pouch inflow amount at the corner parts of the electrode assembly receiving portion formed in the receiving portion of the support unit by insertion due to downward movement of the punch, whereby it is possible to reduce generation of wrinkles.

<FIG> is a perspective view of a stripper according to a third embodiment of the present invention, and <FIG> is a perspective view of a support unit according to a third embodiment of the present invention.

Referring to <FIG> and <FIG>, a pouch shaping apparatus according to a third embodiment of the present invention includes a stripper <NUM> and a support unit <NUM>, wherein the support unit <NUM> includes an upper support <NUM> and a support plate <NUM>. The pouch shaping apparatus according to the third embodiment is identical to the pouch shaping apparatus described with reference to <FIG> except that corresponding bead portions are located at facing surfaces of the stripper and the support unit. Hereinafter, therefore, only the bead portions formed at the stripper and the support unit will be described.

The pouch shaping apparatus according to the third embodiment includes bead portions formed at the stripper and the support unit. Specifically, bead portions are disposed so as to correspond to each other at a pressing surface of the stripper <NUM> that faces the upper surface of the laminate sheet and an upper surface of an upper support frame <NUM> that faces the lower surface of the laminate sheet.

The bead portions include a first bead portion <NUM> located at the stripper <NUM> and a second bead portion <NUM> located at the support unit <NUM>.

A plurality of first bead portions <NUM> is disposed so as to be spaced apart from each other, and a plurality of second bead portions <NUM> is disposed so as to be spaced apart from each other. Four first bead portions <NUM> are disposed at a lower surface of the stripper <NUM> so as to be adjacent respectively to four corner parts thereof, and the second bead portions <NUM> are disposed at an upper surface of the upper support <NUM> so as to be adjacent respectively to four corner parts thereof.

Here, each second bead portion <NUM> may be an "I"-shaped slit that is located at an upper surface of the upper support frame <NUM> of the upper support <NUM>, that is formed in a straight shape having a predetermined length, and that has a concave recess. The "I"-shaped second bead portions <NUM> are located adjacent respectively to four corner parts of a shaping portion <NUM> of the upper support <NUM>, and are located so as to have an oblique angle with respect to two sides that join each other at a right angle of the upper support frame <NUM> constituting the shaping portion <NUM>.

The first bead portions <NUM> are located at the lower surface of the stripper <NUM> that faces the support unit <NUM>. Each of the first bead portions <NUM> is configured in a convex shape corresponding to a corresponding one of the second bead portions <NUM>, each of which is a concave recess, so as to be inserted into a corresponding one of the second bead portions <NUM>. Here, the first bead portions <NUM> are disposed at positions corresponding to the second bead portions <NUM>.

Although the first bead portions <NUM> are convex and the second bead portions <NUM> are concave in the above description, the convex shapes and the concave shapes may be disposed so as to cross each other as long as the first bead portions and the second bead portions are capable of fixing the laminate sheet therebetween.

Four "L"-shaped core members were disposed between an upper support and a support plate so as to be adjacent to corner parts of a shaping portion of the upper support. The thickness of each core member was <NUM>, the length of a long side of each core member was <NUM>, and the length of a short side of each core member was <NUM>. Shaping of a laminate sheet was simulated using a pouch shaping apparatus including the core members, and the maximum displacement of the shaping portion in a direction toward a lower part of a pouch (z-axis direction) was checked.

Shaping of a laminate sheet was simulated in the same manner as in Example <NUM> except that core members each having a thickness of <NUM> were used, and the maximum displacement of a shaping portion in a direction toward a lower part of a pouch (z-axis direction) was checked.

<FIG> shows the results of simulation according to Example <NUM> and Example <NUM> of the present invention. In <FIG>, only <NUM>% of the support plate cut at a middle part thereof in an overall length direction is shown.

Referring to <FIG>, the figure on the left side of <FIG> shows the maximum displacement of Example <NUM> in the Z-axis direction, and the figure on the right side of <FIG> shows the maximum displacement of Example <NUM> in the Z-axis direction.

For Example <NUM>, in which the thickness of each core member was <NUM>, the maximum displacement of the laminate sheet in the shaping portion was <NUM>. For Example <NUM>, in which the thickness of each core member was <NUM>, the maximum displacement of the laminate sheet in the shaping portion was <NUM>. It can be seen therefrom that the displacement of the stretched laminate sheet was increased in proportion to the thickness of each core member.

A laminate sheet was shaped using a pouch shaping apparatus including a two-stage stripper constituted by a first stripper and a second stripper, and the thickness increase rate of the laminate sheet at each corner part of a receiving portion was checked. The increased thickness of the laminate sheet was caused by wrinkles formed at each corner part, which means that the smaller the thickness increase rate, the less wrinkles are generated.

The thickness increase rate of a laminate sheet was checked using the same method as in Example <NUM> except that a stripper including no second stripper was used, unlike the two-stage stripper of Example <NUM>.

<FIG> shows the results of simulation according to Example <NUM> of the present invention, and <FIG> shows the results of simulation according to Comparative Example <NUM> of the present invention.

Referring to <FIG> and <FIG>, when a conventional stripper including no second stripper was used, as in Comparative Example <NUM>, the thickness of each corner part of a receiving portion was increased by <NUM>%. When a two-stage stripper including a second stripper was used, as in Example <NUM>, the thickness of each corner part of the receiving portion was increased by <NUM>%. Consequently, it can be seen that, when the two-stage stripper was used, wrinkles generated at each corner part were reduced.

Claim 1:
A pouch shaping apparatus (<NUM>) comprising:
a support unit (<NUM>, <NUM>) configured to allow a laminate sheet (<NUM>) to be disposed on an upper surface thereof;
a stripper (<NUM>, <NUM>) located above the support unit (<NUM>, <NUM>), the stripper (<NUM>, <NUM>) configured to be movable upwards and downwards, the stripper (<NUM>, <NUM>) configured to press and fix an outer periphery of the laminate sheet (<NUM>) disposed on the upper surface of the support unit (<NUM>, <NUM>) when moved downwards; and
a punch (<NUM>) located above the support unit (<NUM>, <NUM>), the punch (<NUM>) configured to be movable upwards and downwards, the punch (<NUM>) configured to form an electrode assembly (<NUM>) receiving portion in the laminate sheet (<NUM>) while inserted into a shaping portion (<NUM>, <NUM>) located at a center of the support unit (<NUM>, <NUM>) when moved downwards, wherein
the support unit (<NUM>, <NUM>) comprises an upper support (<NUM>, <NUM>) and a support plate (<NUM>, <NUM>),
the pouch shaping apparatus (<NUM>) comprises a core member (<NUM>) located between the upper support (<NUM>, <NUM>) and the support plate (<NUM>, <NUM>), the core member (<NUM>) having a predetermined thickness,
characterized in that
the core member (<NUM>) comprises a plurality of core members (<NUM>), the plurality of core members (<NUM>) disposed spaced apart from each other;
the core members (<NUM>) are disposed at a lower end of the upper support frame (<NUM>, <NUM>) adjacent to corner parts of the shaping portion (<NUM>, <NUM>).