Patent Description:
Secondary batteries that are repetitively chargeable and dischargeable may be divided into cylindrical type secondary batteries, prismatic type secondary batteries, and pouch type secondary batteries according to their structures and manufacturing methods. Among them, such a pouch type secondary battery is manufactured by accommodating an electrode assembly in a pouch sheet to seal the pouch sheet. When compared to other types of secondary batteries, the pouch type secondary battery has a simple structure and high capacity per unit volume and thus is widely used in vehicle batteries or energy storage devices.

In more detail, in the pouch type secondary battery, after forming a cup in a shape that is recessed in the pouch sheet, the electrode assembly is accommodated in the cup, and the pouch sheet is folded so that one area of the pouch sheet covers the electrode assembly. Then, a sealing part that seals a circumference of the electrode assembly is formed to manufacture the pouch type secondary battery.

<FIG> is a cross-sectional view of a sealing device according to a related art.

Referring to <FIG>, in the sealing device <NUM> according to the related art, a heat source <NUM> such as a heat line is built in a sealing tool <NUM> that performs sealing. When the sealing tool <NUM> is heated by the heat source <NUM>, a temperature of the sealing tool <NUM> increases, and thus, a temperature of the sealing surface <NUM>, which is in direct contact with a pouch to performs sealing, increases. Then, the sealing is performed after the temperature of the sealing surface <NUM> increases to a temperature suitable for the sealing.

<FIG> is a view illustrating a variation in temperature of the sealing surface in the sealing device of <FIG>.

Referring to <FIG>, in the sealing device <NUM> according to the related art, the temperature of the sealing surface <NUM> is not always constantly maintained to a sealing target temperature. When the temperature of the sealing surface <NUM> increases above the sealing target temperature, the heat source <NUM> is controlled to be turned off so that the temperature of the sealing surface <NUM> decreases, and when the temperature of the sealing surface <NUM> deceases below the sealing target temperature, the heat source <NUM> is controlled to be is turned on to heat the sealing surface <NUM> so that the temperature of the sealing surface <NUM> increases. Therefore, the temperature of the sealing surface <NUM> is not always constantly maintained and is controlled to draw a wave shape as illustrated in <FIG>.

If the pouch sealing is performed at such an irregular temperature, there are problems in that quality of the pouch sealing part is not uniform, and defects such as leakage or damage occur later.

<CIT> relates to a sealing rail for a packaging machine. The sealing rail has least one heating unit that is provided in a heating bar, and a sealing surface that is provided on a sealing bar. The sealing rail has at least one heat pipe that is oriented parallel to the sealing surface and in contact with both the heating bar and the sealing bar so as to transfer heat homogeneously from the heating bar to the sealing bar.

<CIT> discloses a device for joining stacked objects by application of heat and pressure comprising (a) a heating unit having a rigid metal pressure plate, on a frame, inside which are features, such as heat exchange pipes, wherein the plate contacts the lower side of the stacked objects; and (b) a pressure unit applied to the upper surface of the stack having; an inflatable envelope applied to the frame; an elastomer block; and a deformable metal sheet between the block and the stack. The metal sheet may ensure even temperature and pressure distribution over the stack of objects.

<CIT> encompasses a heat seal die incorporating heat tube technology for controlling the variation of temperature across a heat seal die, and a system and method for portion control size packaging of flowable liquid-containing condiments in a portion size in the range from <NUM> to <NUM> ounces using such a heat seal die.

<CIT> relates to a device for sealing portions of an overlapped pair of single or composite films by contacting or facing an appropriately heated sealing surface of a heat-sealing member. The heat-sealing member is provided with the sealing surface in a part of its outer surface and with a sealed chamber therewithin in the vicinity of the sealing surface. The sealed chamber contains under decompression working liquid for evaporating and generating high-temperature condensable gas by being heated. The heat-sealing member further has a heat source in the interior or the exterior thereof adjacent to at least a part of the sealed chamber for heating the working liquid.

The present invention is devised to solve the above problems, and an object of the present invention is to provide a sealing device in which a temperature of a sealing surface of the sealing device is constantly maintained even though an appropriate solvent is continuously heated using a phase change of a material, thereby manufacturing a pouch sealing part having excellent quality in a product of a pouch type secondary battery.

A sealing device (<NUM>) according to the present invention includes a sealing body (<NUM>) provided with a sealing surface (<NUM>), which is configured to seal a sealing target object, on one surface thereof, a solvent (<NUM>) that is in contact with the other surface of the sealing body (<NUM>) to supply heat to the sealing body (<NUM>), and a heat source (<NUM>) configured to heat the solvent (<NUM>) so that at least a portion of the solvent (<NUM>) is phase-changed into a gas, wherein while at least the portion of the solvent (<NUM>) is phase-changed into the gas, the sealing body (<NUM>) seals the sealing target object, the sealing device (<NUM>)further comprising a housing (<NUM>) having a structure connected to the sealing body (<NUM>) and configured to accommodate the solvent (<NUM>), and a condenser (<NUM>) configured to condense the solvent (<NUM>), which is phase-changed into the gas, into a liquid, wherein the condenser (<NUM>) is disposed above the heat source (<NUM>), and wherein a heat insulating part (<NUM>) is disposed between the heat source (<NUM>) and the condenser (<NUM>).

The housing may include sidewall extending upward from an edge of the sealing body, and the solvent may be contained in an inner space, which has a recessed shape formed by the other surface of the sealing body and the sidewall, in a liquid state.

At least a portion of the heat source may be contained in the solvent that is the liquid state, and the heat source may be spaced a predetermined distance from the sealing body.

The solvent may be vaporized by the heat source to move upward, and the solvent may be liquefied by the condenser to move downward.

The condenser may be disposed in the housing.

The solvent may be made of a material having a boiling point of <NUM> degrees Celsius and <NUM> degrees Celsius.

The solvent may be any one selected from ethylene glycol, propylene glycol, and dimethyl sulfoxide.

The sealing device according to the present invention may include the sealing body having the sealing surface for sealing the sealing target object on one surface, the solvent that is in contact with the other surface of the sealing body to supply the heat to the sealing body, and the heat source that heats the solvent so that at least a portion of the solvent is phase-changed to the gas, and thus, even if the appropriate solvent is continuously heated using the phase change of the material, the temperature of the sealing surface of the sealing device may be maintained constantly. As a result, in the product of the pouch type secondary battery, the pouch sealing part may be manufactured with the uniform and excellent quality.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily carry out the present invention.

In order to clearly explain the present invention, detailed descriptions of portions that are irrelevant to the description or related known technologies that may unnecessarily obscure the gist of the present invention have been omitted, and in the present specification, reference symbols are added to components in each drawing. In this case, the same or similar reference numerals are assigned to the same or similar elements throughout the specification.

<FIG> is a cross-sectional view illustrating a sealing device according to Embodiment <NUM>. <FIG> is a view illustrating a variation in temperature of a sealing surface in the sealing device of <FIG>.

Referring to <FIG>, a sealing device <NUM> according to Embodiment <NUM> may include a sealing body <NUM>, a solvent <NUM>, and a heat source <NUM>.

The sealing body <NUM> may be provided with a sealing surface <NUM> for sealing a sealing target object on one surface. The sealing target object may be a pouch for a secondary battery, which is used as a secondary battery case. Among secondary batteries, a pouch type battery may be manufactured by forming an inner space by molding a pouch coated with a resin on aluminum, accommodating an electrode assembly in the inner space, and sealing a circumferential portion of the pouch disposed around the accommodated electrode assembly. The sealing device <NUM> according to Embodiment <NUM> of the present invention may be used for sealing the pouch in the sealing process while the pouch type secondary battery is manufactured.

The solvent <NUM> may be configured to supply heat to the sealing body <NUM> by being in contact with the other surface <NUM> of the sealing body. The solvent <NUM> has a liquid form and may be provided to be in contact with the other surface <NUM> of the sealing body. The solvent <NUM> may receive heat from the heat source <NUM> to be described below to increase in temperature, and when the temperature of the solvent <NUM> increases, the solvent <NUM> may supply the heat to the sealing body <NUM>.

The heat source <NUM> may be configured to heat the solvent <NUM>. Particularly, the heat source <NUM> may be configured to heat the solvent <NUM> so that at least a portion of the solvent <NUM> is phase-changed from a liquid to a gas. In addition, in the sealing device <NUM> according to Embodiment <NUM>, the sealing body <NUM> may seal a sealing target object through the sealing surface <NUM> while at least a portion of the solvent <NUM> is phase-changed into the gas.

In this way, since the sealing device <NUM> according to Embodiment <NUM> uses a phase change of a material, the temperature of the sealing surface <NUM> of the sealing device <NUM> may be constantly maintained even though the appropriate solvent is continuously heated. As a result, the sealing of the pouch may be performed at a constant temperature. As a result, in the product of the pouch type secondary battery, the pouch sealing part may be manufactured with the uniform and excellent quality.

Referring to <FIG>, it is seen that the temperature of the sealing surface <NUM> is constantly maintained in the sealing device <NUM> according to Embodiment <NUM>. Particularly, the temperature of the sealing surface <NUM> may be maintained constantly according to the sealing target temperature, and in this case, the uniform and excellent sealing quality may be realized.

The sealing target temperature may be a value between <NUM> and <NUM> degrees Celsius. For this, the solvent <NUM> may be a material having a boiling point between <NUM> degrees Celsius and <NUM> degrees Celsius. In an embodiment, the solvent <NUM> may be any one selected from ethylene glycol, propylene glycol, and dimethyl sulfoxide. Ethylene glycol may have a boiling point of about <NUM> degrees Celsius. Propylene glycol may have a boiling point of about <NUM> degrees Celsius. Dimethyl sulfoxide may have a boiling point of about <NUM> degrees Celsius.

In this way, the sealing device <NUM> according to Embodiment <NUM> may perform the sealing at a constant temperature by using the point that when a material is phase-changed, energy is in and out, but there is no temperature change.

In addition, the sealing device <NUM> according to Embodiment <NUM> may further include a housing <NUM> to accommodate the solvent <NUM>. The housing <NUM> has a structure connected to the sealing body <NUM> and may be configured to accommodate the solvent <NUM>. Since the solvent <NUM> is disposed to be in contact with the other surface <NUM> of the sealing body, the housing <NUM> may be configured to extend from the other surface <NUM> of the sealing body.

Specifically, the housing <NUM> may include a sidewall <NUM> extending upward from an edge of the sealing body <NUM>. When the sidewall <NUM> is formed, a space may be provided by the other surface <NUM> and the sidewall <NUM> of the sealing body. Here, the solvent <NUM> may be contained in an inner space of the recessed shape formed by the other surface <NUM> and the sidewall <NUM> of the sealing body in a liquid state. Due to this structure, even if the sealing body <NUM> moves around for the sealing, the solvent <NUM> may always be in contact with the other surface <NUM> of the sealing body.

The heat source <NUM> may be disposed in a shape of which at least a portion is contained in the solvent <NUM> that is in a liquid state to heat the solvent <NUM>. In addition, the heat source <NUM> may be spaced a predetermined distance from the sealing body <NUM>. If the heat source <NUM> is in contact with the sealing body <NUM>, the temperature of the sealing body <NUM>, in particular, the sealing surface <NUM> may be rapidly affected. Thus, the heat source <NUM> may be disposed so as not to touch the sealing body <NUM>.

The sealing device <NUM> according to Embodiment <NUM> may further include a condenser <NUM> for condensing the solvent <NUM>, which is phase-changed into the gas, into a liquid. The condenser <NUM> may be disposed above the heat source <NUM>. In addition, the condenser <NUM> may be disposed in the housing <NUM>. When the condenser <NUM> is disposed in the housing <NUM>, a moving distance of the solvent <NUM> may be minimized to improve efficiency.

A principle of an operation of the solvent <NUM> in the sealing device <NUM> according to Embodiment <NUM> may be described as follows.

First, when the solvent <NUM> is heated by the heat source <NUM> to reach the boiling point, the solvent <NUM> starts to be vaporized and evaporated. During the process in which the solvent <NUM> is evaporated, the temperature of the solvent <NUM> may be constantly maintained, and also, the temperature of the sealing body <NUM> may be constantly maintained during that time.

Referring to <FIG>, the solvent <NUM> heated and vaporized by the heat source <NUM> may move upward (see arrow ① in <FIG>). The solvent <NUM> moving in the upward direction may meet the condenser <NUM>. When the solvent <NUM> meets the condenser <NUM>, the solvent <NUM> may be condensed (see an arrow ② in <FIG>). That is, the solvent may be phase-changed from a gas to a liquid.

The solvent <NUM> may be liquefied by the condenser <NUM> and then move in a downward direction, which is a direction toward the sealing body <NUM> (see an arrow ③ in <FIG>). Thus, the solvent <NUM> may be heated again by the heat source <NUM>. The solvent <NUM> heated in this manner may proceed to a process of being vaporized again and may be continuously circulated in this cycle.

When the cycle is repeated in this manner, the heat source <NUM> may perform the sealing operation while continuously constantly maintaining the temperature of the solvent <NUM> and the temperature of the sealing surface <NUM> even if the heat is continuously supplied.

<FIG> is a cross-sectional view illustrating a sealing device according to Embodiment <NUM> of the present invention.

Embodiment <NUM> of the present invention is different from the sealing device according to Embodiment <NUM> of the present invention in that a heat insulating part <NUM> is further added.

The contents that are duplicated with Embodiment <NUM> will be omitted as much as possible, and Embodiment <NUM> will be described with a focus on the differences. That is, it is obvious that the contents not described in Embodiment <NUM> are supplemented with the contents of Embodiment <NUM> if necessary.

Referring to <FIG>, in a sealing device <NUM> according to Embodiment <NUM> of the present invention, a heat insulating part <NUM> may be provided between a heat source <NUM> and a condenser <NUM>. Since the heat source <NUM> and the condenser <NUM> are disposed in one housing <NUM>, and the heat source <NUM> and the condenser <NUM> care maintained at different temperatures, it may be necessary that heat exchange does not occur between the heat source <NUM> and the condenser <NUM> in consideration of energy efficiency. Thus, the heat insulating part <NUM> that blocks the heat exchange may be provided between the heat source <NUM> and the condenser <NUM>.

Here, specifically, the heat insulating part <NUM> may be a heat insulating gap or a heat insulating plate. Alternatively, the heat insulating part <NUM> may be a heat insulating coating or heat insulating material layer.

The heat insulating gap may provide a space gap between the heat source <NUM> and the condenser <NUM> for the thermal insulation. This gap may be a space gap formed while the heat source <NUM> and the condenser <NUM> are spaced apart from each other. In addition, a gas having a heat insulating property may be filled in the heat insulating gap, and the inside of the heat insulating gap may be provided as a vacuum.

Claim 1:
A sealing device (<NUM>) comprising:
a sealing body (<NUM>) provided with a sealing surface (<NUM>), which is configured to seal a sealing target object, on one surface thereof;
a solvent (<NUM>) that is in contact with the other surface of the sealing body (<NUM>) to supply heat to the sealing body (<NUM>); and
a heat source (<NUM>) configured to heat the solvent (<NUM>) so that at least a portion of the solvent (<NUM>) is phase-changed into a gas,
wherein while at least the portion of the solvent (<NUM>) is phase-changed into the gas, the sealing body (<NUM>) seals the sealing target object, the sealing device (<NUM>)further comprising a housing (<NUM>) having a structure connected to the sealing body (<NUM>) and configured to accommodate the solvent (<NUM>), and characterized in that the sealing device further comprises
a condenser (<NUM>) configured to condense the solvent (<NUM>), which is phase-changed into the gas, into a liquid, wherein the condenser (<NUM>) is disposed above the heat source (<NUM>), and
wherein a heat insulating part (<NUM>) is disposed between the heat source (<NUM>) and the condenser (<NUM>).