Patent Description:
A battery cell is a cell capable of being charged and discharged, and has a wide application range, including relatively small portable electronic devices, mid-sized to large-sized automobiles, and power storage devices.

The battery cell may have a configuration in which a stack body including a positive electrode, a negative electrode, and a separator is disposed in a case and an electrolyte is filled and sealed in the case. The case of the battery cell may have various shapes, such as a pouch shape, a square shape, a round shape, and the like. When a plurality of battery cells are electrically connected to form a battery module, capacity and an output amount of the battery module may further increase.

When the charging and discharging process of the battery cell are repeated, gas by the electrolyte may be generated inside the case. The gas may be accommodated inside the case, and when pressure therein is higher than a certain level, a sealing portion of the case may be released, and the gas may be discharged to the outside of the case.

Accordingly, timing of releasing sealing of the case, a position in which the sealing is first released from the case, a shape of an unsealing portion of the case, or the like may be controlled by a method of regulating the pressure of the gas inside the case. In Patent Document <NUM>, a receiving element for accommodating pouch cells is described. The receiving element comprises a body which is configured as a profile with a contact surface for contact with a sealing seam.

An object of the present disclosure is to increase gas-accommodating capacity of a case of a battery cell.

Another object of the present disclosure is to delay unsealing of a case of a battery cell by gas.

The invention is as defined in independent claims <NUM> and <NUM>.

According to an aspect of the present disclosure, a battery cell includes a case; an electrode assembly including a positive electrode, a negative electrode, and a separator, accommodated in the case; and a venting guide member having a guide groove therein into which a sealing portion of the case is at least partially inserted, and pressing the case to delay opening of the case.

In an embodiment, the electrode assembly may further include a positive electrode tab connected to the positive electrode and drawn out of the case in one direction; and a negative electrode tab connected to the negative electrode and drawn out of the case in a direction, different from the one direction of the positive electrode tab, wherein the sealing portion of the case may include a first sealing portion formed on a surface of the case from which the positive electrode tab is drawn out; and a second sealing portion formed on a surface of the case from which the negative electrode tab is drawn out, wherein the venting guide member may be coupled to the case, to insert at least one of the first sealing portion or the second sealing portion into the guide groove.

Also, in an embodiment, the venting guide member may be coupled to the case such that a region thereof at least partially faces at least one of the positive electrode tab or the negative electrode tab.

In addition, in an embodiment, the venting guide member may be coupled to the case such that end portions of the venting guide member are present on the case in a cross-section taken in a width-height direction of the case.

Also, in an embodiment, the plurality of venting guide members may be spaced apart from each other to sandwich the positive electrode tab and the negative electrode tab therebetween, and may be coupled to the case.

In addition, in an embodiment, in the venting guide member, at least a region thereof may face at least one of the positive electrode tab or the negative electrode tab, and end portions of the venting guide member may extend in an outer circumferential direction of the case in a cross-section taken in a width-height direction of the case, such that the end portions may be present outside of the case.

In addition, in an embodiment, the venting guide member may have a pair of the guide groove, and may further include a tab lead-out hole provided therein to be positioned between the pair of guide grooves, and through which at least one of the positive electrode tab or the negative electrode tab passes.

In addition, in an embodiment, the guide groove may have an intermediate forcedly fitting tolerance or a loose forcedly fitting tolerance with the case, and the tab lead-out hole may have an intermediate forcedly fitting tolerance or a loose forcedly fitting tolerance with at least one of the positive electrode tab or the negative electrode tab.

The present disclosure provides a battery module including a battery cell as another aspect.

A battery module according to an embodiment of the present disclosure may include a module housing; at least one battery cell accommodated in the module housing; and a bus bar unit electrically connected to a positive electrode tab and a negative electrode tab of the battery cell, wherein the battery cell may include a case; an electrode assembly accommodated in the case, and including a positive electrode to which the positive electrode tab is connected, a negative electrode to which the negative electrode tab is connected, and a separator interposed between the positive electrode and the negative electrode; and a venting guide member having a guide groove therein into which a sealing portion of the case is at least partially inserted, and pressing the case to delay opening of the case.

Also, in an embodiment, the battery cell may be seated in the module housing such that the case does not contact the module housing.

Also, in an embodiment, the venting guide member may be in contact with the module housing.

In order to help understanding of a description of embodiments of the present disclosure, elements indicated with the same reference numerals in the accompanying drawings are the same elements, and related elements among the elements that perform the same action in each embodiment are denoted by the same or related numerals.

In addition, in order to clarify a gist of the present disclosure, a description of elements and techniques well known in the prior art will be omitted, and hereinafter, the present disclosure will be described in detail with reference to the accompanying drawings.

However, it can be understood that the spirit of the present disclosure is not limited to embodiments to be provided, and specific components may be proposed in other forms in which specific elements are added, changed, or deleted by those skilled in the art, but this is also included within the scope of the same spirit as the present disclosure.

Hereinafter, as illustrated in the accompanying drawings, an X-axis is a width direction of a battery cell, a Y-axis is a height direction of the battery cell, and a Z-axis is a thickness direction of the battery cell.

<FIG> schematically illustrates a battery cell <NUM> according to an embodiment of the present disclosure.

As illustrated in <FIG>, a battery cell <NUM> may include a case <NUM> having a pouch shape, and the case <NUM> may accommodate at least one electrode assembly <NUM> and an electrolyte therein.

A positive electrode tab <NUM> connected to a positive electrode (not illustrated) of the electrode assembly <NUM> and a negative electrode tab <NUM> connected to a negative electrode (not illustrated) of the electrode assembly <NUM> may be drawn out of the case <NUM>, and a lead film (not illustrated) may be present between the positive electrode tab <NUM> and the case <NUM> and between the negative electrode tab <NUM> and the case <NUM> in a thickness direction of the case <NUM>.

An outer surface of the case <NUM> may be formed of a material containing an aluminum alloy, and an inner surface of the case <NUM> may be formed of a material containing polypropylene. The case <NUM> may be heat-sealed to seal a space in which the electrode assembly <NUM> and the electrolyte are accommodated.

In an embodiment of the present disclosure, the case <NUM> may be heat-sealed in a state in which the positive electrode tab <NUM> and the negative electrode tab <NUM> are drawn out of the case <NUM>, and a heat-sealed region in the case <NUM> may become a sealing portion <NUM>. The sealing portion <NUM> may be present in plurality in the case <NUM>.

The sealing portion <NUM> may include a first sealing portion <NUM> formed in a region from which the positive electrode tab <NUM> is drawn out, and a second sealing portion <NUM> formed in a region from which the negative electrode tab <NUM> is drawn out. The sealing portion <NUM> may further include a third sealing portion (not illustrated) and a fourth sealing portion (not illustrated), formed in a direction, parallel to the X-axis, in addition to the first sealing portion <NUM> and the second sealing portion <NUM>. However, this is not necessarily limited by the present disclosure, and the number of sealing portions and a region in which the sealing portions are formed may be appropriately selected and applied according to specifications and the like required for the battery cell <NUM>.

The first sealing portion <NUM> and the second sealing portion <NUM> may be formed by overlapping and heat sealing of both surfaces of the case <NUM>.

Gas generated by the electrolyte may be accommodated in a space between the first sealing portion <NUM> and the electrode assembly <NUM> inside the case <NUM>. In addition, the gas generated by the electrolyte may be accommodated in a space between the second sealing portion <NUM> and the electrode assembly <NUM> inside the case <NUM>.

The gas generated by the electrolyte may stay inside the case <NUM>, since the case <NUM> may be sealed by the first sealing portion <NUM> and the second sealing portion <NUM> until a pressure of a certain level is reached. When the pressure of the gas exceeds a bonding force of the case <NUM> between the first sealing portion <NUM> and the second sealing portion <NUM>, sealing of the case <NUM> may be released in the first sealing portion <NUM> and the second sealing portion <NUM>, to discharge the gas to the outside of the case <NUM>.

In the first sealing portion <NUM> according to an embodiment of the present disclosure, a bonding force in a region facing the positive electrode tab <NUM> may be weaker than a bonding force in a region not facing the positive electrode tab <NUM>. In addition, in the second sealing portion <NUM>, a bonding force in a region facing the negative electrode tab <NUM> may be weaker than a bonding force in a region not facing the negative electrode tab <NUM>.

In this case, since the gas inside the case <NUM> may be concentrated toward a region in which the positive electrode tab <NUM> and the negative electrode tab <NUM> are present, a point in time of unsealing the case <NUM> may be advanced, compared to when a bonding force of the first sealing portion <NUM> is equal to a bonding force of the second sealing portion <NUM> in a direction, parallel to the Y-axis. Therefore, gas-accommodating capacity of the case <NUM> may be relatively reduced.

According to an embodiment of the present disclosure, a battery cell <NUM> may include a plurality of venting guide members <NUM> coupled to the case <NUM> to press a region of the first sealing portion <NUM> facing the positive electrode tab <NUM> and a region of the second sealing portion <NUM> facing the negative electrode tab <NUM>.

In this case, the plurality of venting guide members <NUM> may be coupled to the case <NUM>, not to press at least a region of a region of the case <NUM> not facing the positive electrode tab <NUM> and at least a region of a region of the case <NUM> not facing the negative electrode tab <NUM>.

In an embodiment of the present disclosure, a venting guide member <NUM> may be forcedly fitted and coupled to the case <NUM>. In this case, the positive electrode tab <NUM> and the negative electrode tab <NUM> may pass through the venting guide member <NUM>.

The venting guide member <NUM> forcedly fitted to the case <NUM> may be in contact with one surface and the other surface of the case <NUM>, respectively, and the one surface and the other surface of the case <NUM> may be pressed in the thickness direction of the case <NUM>. In this case, a region of the positive electrode tab <NUM> and a region of the negative electrode tab <NUM> may also be pressed by the venting guide member <NUM>.

The venting guide member <NUM> may prevent an additional increase in bonding force of a portion having a relatively strong bonding force in the first sealing portion <NUM> and the second sealing portion <NUM>, while reinforcing a bonding force of a portion having a relatively weak bonding force. According to the venting guide member <NUM>, the first sealing portion <NUM> and the second sealing portion <NUM> may have a uniform bonding force in a direction, parallel to the Y-axis.

In addition, according to the venting guide member <NUM>, since a bonding force of the first sealing portion <NUM> and a bonding force of the second sealing portion <NUM> are uniform, a portion of the first sealing portion <NUM> and a portion of the second sealing portion <NUM> may be prevented from being unsealed first. Therefore, a point in time at which gas inside the case <NUM> unseals the case <NUM> may be delayed, and gas-accommodating capacity of the case <NUM> may increase.

The venting guide member <NUM> may be formed of a material including a plastic having a certain level of dielectric strength, but the material is not necessarily limited by the present disclosure, and may be matters that may be appropriately selected and applied according to a usage environment, standards, specifications, or the like of the battery cell <NUM>.

In another embodiment of the present disclosure, a venting guide member <NUM> may be coupled to the case <NUM>, to press only one sealing portion of the first sealing portion <NUM> or the second sealing portion <NUM>. This may be appropriately selected and applied in consideration of a bonding characteristic of the first sealing portion <NUM>, a bonding characteristic of the second sealing portion <NUM>, a venting characteristic of the battery cell <NUM>, or the like.

<FIG> schematically illustrates a battery cell <NUM> according to another embodiment of the present disclosure.

As illustrated in <FIG>, in a first sealing portion <NUM> of a battery cell <NUM> according to another embodiment of the present disclosure, a bonding force in a region in which a positive electrode tab <NUM> is not present may be weaker than a bonding force in a region in which the positive electrode tab <NUM> is present.

Also, in a second sealing portion <NUM>, a bonding force in a region in which a negative electrode tab <NUM> is not present may be weaker than a bonding force in a region in which the negative electrode tab <NUM> is present.

In another embodiment of the present disclosure, a venting guide member <NUM> may be coupled to a case <NUM>, to press a region having a relatively weak bonding force in the first sealing portion <NUM> and the second sealing portion <NUM>.

In another embodiment of the present disclosure, a venting guide member <NUM> may include a first venting guide member <NUM> and a second venting member <NUM>, coupled to the case <NUM>, to cover at least a region of the first sealing portion <NUM>.

The first venting guide member <NUM> may be present on the positive electrode tab <NUM> in a +Y direction, and the second venting guide member <NUM> may be present below the positive electrode tab <NUM> in a -Y direction. The first venting guide member <NUM> and the second venting guide member <NUM> may be spaced apart from each other with the positive electrode tab <NUM> interposed therebetween.

The first venting guide member <NUM> and the second venting guide member <NUM> may be provided in plurality, to also press the second sealing portion <NUM>. In the second sealing portion <NUM>, a first venting guide member <NUM> may be present on the negative electrode tab <NUM> in the +Y direction, and a second venting guide member <NUM> may be present below the negative electrode tab <NUM> in the -Y direction.

A plurality of first venting guide members <NUM> and a plurality of second venting guide members <NUM> may be formed by additionally pressing a region having a relatively weak bonding force in the first sealing portion <NUM> and the second sealing portion <NUM>. The first sealing portion <NUM> and the second sealing portion <NUM> may have uniform bonding force in a direction, parallel to the Y-axis.

In this case, an end portion 131a of the first venting guide member <NUM> in the +Y direction and an end portion 132a of the second venting guide member <NUM> in the -Y direction may be present outside the case <NUM>. According to this, the first venting guide member <NUM> and the second venting guide member <NUM> may surround a bat ear portion of the case <NUM>.

The bat ear portion may be a region in which particles of the case <NUM> are concentrated and protrude during a heat-sealing process of the case <NUM> or a folding process of the case <NUM>, and may be a region from which a portion of an aluminum layer of the case <NUM> is exposed. The bat ear portion may mainly occur in an outer peripheral region of the case <NUM>. Therefore, when the first venting guide member <NUM> and the second venting guide member <NUM> surround the bat ear portion, exposure of the aluminum layer outside the case <NUM> may be prevented, and breakage of insulation of the case <NUM> may be prevented.

As illustrated in <FIG>, a first sealing portion <NUM> and a second sealing portion <NUM> of a battery cell <NUM> according to another embodiment of the present disclosure may have uniform bonding force in a direction, parallel to the Y-axis.

In another embodiment of the present disclosure, a venting guide member <NUM> may press the first sealing portion <NUM> and a positive electrode tab <NUM> on the same line in a direction, parallel to the Y-axis.

In another embodiment of the present disclosure, a plurality of venting guide members <NUM> may be provided to press the second sealing portion <NUM> and a negative electrode tab <NUM> on the same line in a direction, parallel to the Y-axis.

The first sealing portion <NUM>, the positive electrode tab <NUM>, the second sealing portion <NUM>, and the negative electrode tab <NUM> may be pressed by the venting guide member <NUM> to uniformly increase a bonding force of the first sealing portion <NUM> and a bonding force of the second sealing portion <NUM>. Therefore, a point in time at which sealing of a case <NUM> is released may be delayed, and a time period at which gas is accommodated in the case <NUM> may increase.

An end portion 130a of the venting guide member <NUM> in a direction, parallel to the Y-axis, may be present outside the case <NUM>, and the other end portion 130b of the venting guide member <NUM> in a direction, parallel to the Y-axis, may be also present outside the case <NUM>. According to this, the above-described bat ear portion may be surrounded by the venting guide member <NUM>, and exposure of an aluminum layer outside the case <NUM> may be prevented, to contribute to maintaining insulation of the case <NUM>.

<FIG> is a perspective view of a venting guide member <NUM> according to an embodiment of the present disclosure.

As illustrated in <FIG>, a venting guide member <NUM> according to an embodiment of the present disclosure may be provided with a pair of guide grooves <NUM> therein, and at least a region of a case (<NUM> in <FIG>) may be inserted into a guide groove <NUM>. The case (<NUM> in <FIG>) inserted into the guide groove <NUM> may be pressed by the venting guide member <NUM>.

A tab lead-out hole <NUM> may be provided between the pair of guide grooves <NUM> in the Y-axis direction of the venting guide member <NUM>. The tab lead-out hole <NUM> may be a through-hole formed inside the venting guide member <NUM>, through which a positive electrode tab (<NUM> in <FIG>) or a negative electrode tab (<NUM> in <FIG>) may pass, and the positive electrode tab (<NUM> in <FIG>) or the negative electrode tab (<NUM> in <FIG>) passing through the tab lead-out hole <NUM> may be exposed outside the venting guide member <NUM>.

The case (<NUM> in <FIG>) may be positioned inside the guide groove <NUM>, and may not be exposed outside the venting guide member <NUM>. According to this, a phenomenon of exposing an aluminum layer of the case (<NUM> in <FIG>) outside the venting guide member <NUM> to break insulation thereof may be prevented.

The positive electrode tab (<NUM> in <FIG>) or the negative electrode tab (<NUM> in <FIG>) may pass through the tab lead-out hole <NUM>, to be exposed outside the venting guide member <NUM>. According to this, the positive electrode tab (<NUM> in <FIG>) or the negative electrode tab (<NUM> in <FIG>) may be easily connected to a bus bar (not illustrated).

<FIG> is a perspective view illustrating the venting guide member <NUM> of <FIG> from another viewpoint.

As illustrated in <FIG>, the tab lead-out hole <NUM> may be a through-hole formed in the venting guide member <NUM> in a direction, parallel to the X-axis. The positive electrode tab (<NUM> in <FIG>) or the negative electrode tab (<NUM> in <FIG>) may be inserted into one side opening of the tab lead-out hole <NUM>, and the positive electrode tab (<NUM> in <FIG>) or the negative electrode tab (<NUM> in <FIG>) may be drawn out of the other side opening of the tab lead-out hole <NUM>.

<FIG> is an exploded perspective view of a venting guide member <NUM> and a case <NUM> according to an embodiment of the present disclosure.

As illustrated in <FIG>, a positive electrode tab <NUM> may be inserted into one side opening of a tab lead-out hole <NUM> and may be drawn out of the other side opening of the tab lead-out hole <NUM>, and at least a region of a case <NUM> and at least a region of a first sealing portion <NUM> of the case <NUM> may be inserted into a guide groove <NUM>.

In an embodiment of the present disclosure, a tab lead-out hole <NUM> may be provided to have an intermediate forcedly fitting tolerance or a loose forcedly fitting tolerance with a positive electrode tab (<NUM> in <FIG>) or a negative electrode tab (<NUM> in <FIG>). In addition, a guide groove <NUM> may be provided to have an intermediate forcedly fitting tolerance or a loose forcedly fitting tolerance with the case <NUM>. According to this, assembly of the venting guide member <NUM> and the case <NUM> may be facilitated, and when the venting guide member <NUM> is assembled with the case <NUM>, the venting guide member <NUM> may cause to press the first sealing portion <NUM>.

Even when a region of the case <NUM> is inserted together into the tab lead-out hole <NUM>, the case <NUM> may have a relatively thin film. In this case, even though an intermediate forcedly fitting tolerance or a loose forcedly fitting tolerance is formed between the tab lead-out hole <NUM> and the positive electrode tab <NUM>, the case <NUM> may be inserted into the tab lead-out hole <NUM> without unreasonableness within ranges of the tolerance. As necessary, a value obtained by adding a thickness of the case <NUM> to a thickness of the positive electrode tab <NUM> may be determined as a thickness of the positive electrode tab <NUM>, and based on the thickness of the positive electrode tab <NUM> determined in this manner, an intermediate forcedly fitting tolerance or a loose forcedly fitting tolerance with the tab lead-out hole <NUM> may be formed.

In an embodiment of the present disclosure, a depth at which the case <NUM> is inserted into the guide groove <NUM> and a depth at which the positive electrode tab <NUM> is inserted into the tab lead-out hole <NUM> may be controlled to adjust an amount of increasing a bonding force of the first sealing part <NUM>.

As the case <NUM> and the positive electrode tab <NUM> are inserted more deeply into the guide groove <NUM> and the tab lead-out hole <NUM> in the -X direction, a bonding force of the first sealing portion <NUM> may increase in a relative large amount. As the case <NUM> and the positive electrode tab <NUM> are inserted more shallowly into the guide groove <NUM> and the tab lead-out hole <NUM> in the -X direction, the bonding force of the first sealing portion <NUM> may increase in a relative small amount. This may be equally applied to the second sealing portion (<NUM> in <FIG>) in which the negative electrode tab (<NUM> in <FIG>) is present.

In an embodiment of the present disclosure, a width of the first sealing portion <NUM> and a width of the second sealing portion (<NUM> in <FIG>) in a direction, parallel to the X-axis, may be <NUM>, respectively. In this case, a depth at which the case <NUM> and the positive electrode tab <NUM> are inserted into the guide groove <NUM> and the tab lead-out hole <NUM> in a direction, parallel to the X-axis, in the first sealing portion <NUM> may be a value of <NUM> or more and <NUM> or less. This may be equally applied to the negative electrode tab (<NUM> in <FIG>) and the case <NUM> in the second sealing portion (<NUM> in <FIG>).

However, the above numerical values are not necessarily limited by the present disclosure, and may be appropriately selected and applied according to a usage environment of the battery cell <NUM>, specifications required for the battery cell <NUM>, or the like.

<FIG> is an exploded perspective view of a venting guide member <NUM> and a case <NUM> according to another embodiment of the present disclosure.

As illustrated in <FIG>, when a folded portion <NUM> is formed by rolling one end portion of a case <NUM>, the folded portion <NUM> may have a protruding shape, compared to other regions of the case <NUM>. Therefore, in another embodiment of the present disclosure, a guide groove <NUM> may include a folded portion insertion region 133a having a width corresponding to the folded portion <NUM>. The folded portion insertion region 133a may be provided to have an intermediate forcedly fitting tolerance or a loose forcedly fitting tolerance with the folded portion <NUM>.

<FIG> schematically illustrates a gas-accommodating space S inside a case <NUM> to which a venting guide member (<NUM> in <FIG>) is not applied.

As illustrated in <FIG>, a width of a gas-accommodating space S in a direction, parallel to the X-axis, may have a section ranging from an end portion of a separator (not illustrated) of an electrode assembly <NUM> just to a first sealing portion <NUM> in the -X direction. The gas-accommodating space S may have the aforementioned section as a width, and a height of the gas-accommodating space S in a direction, parallel to the Y-axis, may be equal to a height 123a of an accommodation space <NUM> for accommodating the electrode assembly <NUM>. However, these may be a width and a height of the gas-accommodating space S before a sealing portion releasing region A<NUM> is generated in the first sealing portion <NUM>.

Gas generated by an electrolyte in the accommodation space <NUM> may be present in the gas-accommodating space S, and as a pressure thereof gradually increases, the gas may permeate into a region of the first sealing portion <NUM> to release a region of the first sealing portion <NUM>, and a sealing portion releasing region A<NUM> may be formed in the first sealing portion <NUM>.

A volume of the sealing portion releasing region A<NUM>, which is a region in which the sealing is partially released in the first sealing portion <NUM>, may gradually increase, as a pressure of the gas increases. When the pressure of the gas is concentrated in the sealing portion releasing region A<NUM>, an open portion D<NUM> may be generated in the first sealing portion <NUM>, and bonding of the first sealing portion <NUM> may be discontinuous in a direction, parallel to the X-axis. Then, as the sealing of the case <NUM> is completely released, the gas may be discharged outside the case <NUM>. In this case, the first sealing portion <NUM> in which the sealing portion releasing region A<NUM> and the open portion D<NUM> are not present may not fulfill its role.

<FIG> schematically illustrates a gas-accommodating space S inside a case <NUM> to which a venting guide member <NUM> is applied according to an embodiment of the present disclosure.

Until a sealing portion releasing region A<NUM> occurs in a first sealing portion <NUM>, a gas-accommodating space S may have a volume, equal to the volume of the gas-accommodating space S illustrated in <FIG>.

When a pressure of gas in the gas-accommodating space S increases, the sealing portion releasing region A<NUM> may be generated in the first sealing portion <NUM>, but a maximum width of the sealing portion releasing region A<NUM> in a direction, parallel to the X-axis, may be limited to a section ranging from from the first sealing portion <NUM> just to a venting guide member <NUM>. Since the venting guide member <NUM> presses the first sealing portion <NUM>, sealing of a case <NUM> may not be released before a pressure of the gas exceeding a pressing force of the venting guide member <NUM> is reached.

As illustrated in <FIG>, as a pressure of gas gradually increases, a volume of a sealing portion releasing region A<NUM> may also gradually increase, but a maximum width of the sealing portion releasing region A<NUM> in a direction, parallel to the X-axis, may be limited, a volume of the sealing portion releasing region A<NUM> may increase, as a height of the sealing portion releasing region A<NUM> in a direction, parallel to the Y-axis, increases.

In some cases, a second sealing portion releasing region A<NUM> may be subsequently generated in the first sealing portion <NUM>. In this case, a sealing portion releasing region A<NUM>, first generated, may be provided as a first sealing portion releasing region A<NUM>.

As illustrated in <FIG>, when a pressure of gas gradually increases even after a first sealing portion releasing region (A<NUM> in <FIG>) and a second sealing portion releasing region (A<NUM> in <FIG>) occur, bonding of a case <NUM> in a first sealing portion (<NUM> in <FIG>) may be entirely released, such that a width of a gas-accommodating space in a direction, parallel to the X-axis, becomes a value obtained by adding an initial width of the first sealing portion (<NUM> in <FIG>).

Therefore, according to the present disclosure, the width of the gas-accommodating space may be further increased by a width of a region in which a venting guide member <NUM> is not present in the first sealing portion <NUM>. This means that an amount of gas that may be present in the gas-accommodating space increases, and that a point in time of unsealing the case <NUM> is delayed by the amount. According to the present disclosure as described above, gas-accommodating capacity of the case <NUM> of the battery cell may increase, and a point in time at which sealing of the case <NUM> of the battery cell is released by the gas may be also delayed.

<FIG> schematically illustrates a portion of a battery module <NUM> according to an embodiment of the present disclosure.

As illustrated in <FIG>, a battery module <NUM> according to an embodiment of the present disclosure may include a module housing <NUM>, at least one battery cell <NUM> seated in the module housing <NUM>, and a bus bar unit <NUM> electrically connected to a positive electrode tab <NUM> and a negative electrode tab <NUM> of the battery cell <NUM>.

The battery cell <NUM> may be provided as a plurality of battery cells <NUM> according to capacity of the battery module <NUM>, and the plurality of battery cells <NUM> may be stacked in a direction, parallel to the Z-axis. In this case, the bus bar unit <NUM> may also extend in a direction, parallel to the Z-axis, and the positive electrode tab <NUM> and the negative electrode tab <NUM> of the battery cell <NUM> may be electrically connected to the bus bar unit <NUM>.

The bus bar unit <NUM> may include a bus bar member (not illustrated) to which the positive electrode tab <NUM> and the negative electrode tab <NUM> are welded, and a bus bar frame (not illustrated) supporting the bus bar member, but is not limited by the present disclosure, and may be appropriately selected and applied according to standards of the battery module <NUM>, specifications required for the battery module <NUM>, or the like.

A material such as a thermal resin may be applied between the battery cell <NUM> and the module housing <NUM>, and a cooling member (not illustrated) for cooling may be provided in the module housing <NUM>.

In an embodiment of the present disclosure, a venting guide member <NUM> of the battery cell <NUM> may be provided as a plurality of venting guide members <NUM>, and the plurality of venting guide members <NUM> may be coupled to a case <NUM> to press a first sealing portion <NUM> and a second sealing portion <NUM>.

The venting guide member <NUM> may extend in a direction, parallel to the Y-axis. The other end portion 130b of the venting guide member <NUM> may be present outside the case <NUM>, and may be in contact with the module housing <NUM>. This may correspond to the plurality of venting guide members <NUM> pressing the first sealing portion <NUM> and the second sealing portion <NUM>.

The other end portion 130b of the venting guide member <NUM> may be in contact with the module housing <NUM>, such that the case <NUM> of the battery cell <NUM> may not be in contact with the module housing <NUM>, and a gap G may be present between the case <NUM> and the module housing <NUM>.

The gap G may serve to separate the case <NUM> from the module housing <NUM>, and may be a space in which an electrolyte flowing out of the case <NUM> exists. The electrolyte flowing out of the case <NUM> may be a medium for energization. Therefore, it is possible to contribute to preventing dielectric breakdown by accommodating the electrolyte in the gap G and preventing the electrolyte from coming into contact with the case <NUM> from the outside of the case <NUM>.

However, the case <NUM> may be in direct contact with the module housing <NUM> according to specifications required for the battery module <NUM>, standards of the battery module <NUM>, or the like, which is not necessarily limited by the present disclosure.

According to the present disclosure, gas-accommodating capacity of a case of a battery cell may increase.

In addition, according to the present disclosure, unsealing of a case of a battery cell may be delayed by gas.

Claim 1:
A battery cell (<NUM>) comprising:
a case (<NUM>);
an electrode assembly (<NUM>) including a positive electrode, a negative electrode, and a separator, accommodated in the case (<NUM>) ;
a venting guide member (<NUM>) having a guide groove (<NUM>) therein into which a sealing portion (<NUM>, <NUM>) of the case (<NUM>) is at least partially inserted, and pressing the case (<NUM>) to delay opening of the case (<NUM>);
the electrode assembly (<NUM>) further comprising a positive electrode tab (<NUM>) connected to the positive electrode and drawn out of the case (<NUM>) in one direction; and
a negative electrode tab (<NUM>) connected to the negative electrode and drawn out of the case (<NUM>) in a direction, different from the one direction of the positive electrode tab,
wherein the sealing portion (<NUM>, <NUM>) of the case comprises:
a first sealing portion (<NUM>) formed on a surface of the case (<NUM>) from which a positive electrode tab (<NUM>) is drawn out; and
a second sealing portion (<NUM>) formed on a surface of the case (<NUM>) from which a negative electrode tab (<NUM>) is drawn out,
wherein a bonding force of the first sealing portion (<NUM>)in a region facing the positive electrode tab (<NUM>) is weaker than in a region not facing the positive electrode tab (<NUM>) and a bonding force of the second sealing portion (<NUM>) in a region facing the negative electrode tab (<NUM>) is weaker than in a region not facing the negative electrode tab (<NUM>), or wherein a bonding force in a region of the first sealing portion (<NUM>) in which the positive electrode tab (<NUM>) is not present is weaker than in a region of the first sealing portion (<NUM>) in which the positive electrode tab (<NUM>) is present and a bonding force in a region of the second sealing portion (<NUM>) in which the negative electrode tab (<NUM>) is not present is weaker than in a region of the second sealing portion (<NUM>) in which the negative electrode tab (<NUM>) is present, and
wherein the region of the first sealing portion (<NUM>) having the relatively weaker bonding force and the region of the second sealing portion (<NUM>) having the relatively weaker bonding force are pressed by the venting guide member (<NUM>).