Patent Description:
In a pouch-type battery cell, if a positive electrode tab and a negative electrode tab are drawn in different directions and thus a positive electrode lead connected to the positive electrode tab and a negative electrode lead connected to the negative electrode tab are also drawn in different directions, a sensing line for sensing a voltage of the battery cell is inevitably elongated very long.

Referring to <FIG>, a pouch-type battery cell <NUM> in which a pair of electrode leads 1a, 1b are drawn in opposite directions is depicted.

For sensing a voltage of the battery cell <NUM>, the positive electrode lead 1a and the negative electrode lead 1b located at opposite sides should be connected to a voltage sensor <NUM> by using a sensing wire <NUM>, respectively. Thus, in the bi-directional drawing-type battery cell, the sensing wire <NUM> inevitably has a very long length.

If the sensing wire <NUM> has a long length, the complicated sensing structure causes space limitation in the module, and also the sensing wire <NUM> is more likely to be damaged due to interference with other components.

<CIT> relates to a double-tabbed cell and battery pack. Positive foil and negative foil coated respectively with active materials and over both surfaces are stacked to a plurality of layers via separators, and the stack is sealed in a packaging material as immersed in an electrolyte. The positive foil and negative foil of each layer are joined respectively to the positive tab and negative tab, and the positive tab and the negative tab are projected from the packaging material. Along the positive and negative tabs and, detecting terminals are disposed for detection of the output voltage between the positive tab and the negative tab, respectively.

<CIT> refers to a flat battery. A battery has an electrochemical reaction element, outer members to store the electrochemical reaction element and an electric terminal to output electric energy generated from the electrochemical reaction element or electrical information to the outside of the outer members. In this case, at least parts of the outer members are formed as the sealed parts of a film structure and an electric terminal is provided in the sealed part to be planely exposed to the outside of the outer members in the perpendicular direction to the sealed face.

<CIT> relates to an energy storage device. A metal foil laminate package for an electrochemical cell has a multilayered structure comprising a metal foil sandwiched between layers of a thermoplastic and a heat-sealable polymer. An electrically conducting tab extends from the cell and has a layer of insulative tape disposed on both sides of the tab. Apertures formed through the various layers of the package expose both sides of the tab, providing sites for subsequent welding of the tab to external circuitry.

<CIT> refers to a connection between a conductive substrate and laminate.

The present disclosure is designed to solve the problems of the related art, and therefore the present disclosure is directed to providing a structure in which a sensing wire is capable of being installed at only one side of a battery cell to minimize a length of the installed sensing wire and also minimize the possibility of short circuit between a sensing lead for connecting the sensing wire and an electrode lead adjacent thereto.

According to the present invention, there is provided a battery cell as defined in claim <NUM>. The battery cell comprises: an electrode assembly having a pair of electrode tabs; a pair of electrode leads connected to the electrode tabs; and a pouch case configured to accommodate the electrode assembly. The pouch case is sealed in a state where the electrode leads are exposed to the outside of the pouch case, wherein the pouch case comprises an accommodation portion for accommodating the electrode assembly and a sealing portion extending in a circumferential direction of the accommodation portion. The battery cell is a bidirectional drawing-type battery cell in which the pair of electrode leads are drawn in opposite directions, wherein the battery cell includes a sensing lead connected to one of the electrode tabs, wherein the sensing lead is located at the sealing portion at one side or the other side of the battery cell. The sensing lead extends in parallel to any one of the pair of electrode leads adjacent thereto, wherein the sensing lead is located to be adjacent to any one of the pair of electrode leads having opposite polarity than the sensing lead, and wherein the sensing lead does not extend to the outside of the pouch case but is located at the inside thereof, and is exposed to the outside through a sensing hole formed in the sealing portion of the pouch case, wherein the sensing hole is formed in at least one of upper and lower surfaces of the pouch case.

There is also provided a battery module as defined in claim <NUM>. The battery module comprises: the pouch-type battery cell according to the above; a voltage sensor configured to sense a voltage of the battery cell; and a sensing wire configured to connect the battery cell and the voltage sensor.

The sensing wire may connect the sensing lead to the voltage sensor and also connect the electrode lead adjacent to the sensing lead to the voltage sensor.

The sensing hole may be formed in an upper or lower surface of the pouch case.

The sensing wire may be connected to the sensing lead by a solder.

The sensing hole may be formed in both of upper and lower surfaces of the pouch case.

A receptacle may be connected to an end of the sensing wire, and the receptacle may be in contact with and elastically presses both surfaces of the sensing lead.

According to an embodiment of the present disclosure, since the sensing wire is capable of being installed only at one side of the battery cell, the length of the installed sensing wire may be minimized.

According to another embodiment of the present disclosure, the possibility of short circuit between a sensing lead for connecting the sensing wire and an electrode lead adjacent thereto sensing wire may be minimized.

Therefore, the description proposed herein is for the purpose of illustrations only, not intended to limit the scope of the disclosure, so it should be understood that other equivalents and modifications could be made thereto within the scope of the appended claims.

The overall configuration of a battery module according to an embodiment of the present disclosure will be described with reference to <FIG>.

<FIG> is a plane view showing a battery module according to an embodiment of the present disclosure.

Referring to <FIG>, a battery module according to an embodiment of the present disclosure includes a pouch-type battery cell <NUM>, a voltage sensor <NUM> for sensing a voltage of the battery cell <NUM>, and a sensing wire <NUM> for electrically connecting a positive electrode and a negative electrode of the battery cell <NUM> to the voltage sensor <NUM>.

The battery cell <NUM> employed at the present disclosure is a pouch-type battery cell and includes an electrode assembly <NUM>, a pouch case <NUM>, a pair of electrode leads <NUM>, <NUM>, a pair of sealants <NUM>, <NUM> and a sensing lead <NUM>.

The electrode assembly <NUM> is configured so that a positive electrode plate, a separator and a negative electrode plate are stacked at least once, and the separator is preferably located at both outer sides for insulation.

Though not shown in the figures, the positive electrode plate includes a positive electrode current collector and a positive electrode active material layer coated on at least one surface thereof, and a positive electrode uncoated region not coated with the positive electrode active material layer is formed at one end thereof. The positive electrode uncoated region serves as a positive electrode tab 11a connected to the positive electrode lead <NUM>.

Similarly, the negative electrode plate includes a negative electrode current collector and a negative electrode active material layer coated on at least one surface thereof, and an uncoated region not coated with the active material layer is formed at one end thereof. The uncoated region serves as a negative electrode tab 11a connected to the negative electrode lead <NUM>.

In this specification, for example, the electrode lead <NUM> located at the right in <FIG> is called a positive electrode lead, and the electrode lead <NUM> located at the left is called a negative electrode lead. However, the present disclosure is not limited thereto, and the polarities may be formed on the contrary.

Meanwhile, when being stacked, the positive electrode plate and the negative electrode plate are disposed so that the electrode tabs 11a having different polarities, namely the positive electrode tab and the negative electrode tab, are oriented to opposite sides.

In addition, the separator is interposed between the positive electrode plate and the negative electrode plate to prevent the electrode plates having different polarities from directly contacting, and is made of a porous material to allow ion passage.

The electrode leads <NUM>, <NUM> are classified into a positive electrode lead <NUM> connected to the positive electrode tab and a negative electrode lead <NUM> connected to the negative electrode tab. Since the positive electrode tab and the negative electrode tab are oriented oppositely as described above, the positive electrode lead <NUM> and the negative electrode lead <NUM> also extend in opposite directions accordingly.

Meanwhile, the electrode leads <NUM>, <NUM> are generally made of an aluminum material coated with nickel, and such metallic electrode leads <NUM>, <NUM> are not easily adhered to an inner surface of the pouch case <NUM> when the pouch case <NUM> is sealed.

Thus, in the sealing region of the pouch case <NUM>, a portion where the electrode leads <NUM>, <NUM> are drawn may have weak sealing. For this reason, in order to improve the sealing property, sealants <NUM>, <NUM> made of a resin material with good adhesion to the inner surface of the pouch case <NUM> may be attached to the periphery of the electrode leads <NUM>, <NUM>.

The pouch case <NUM> may be composed of an upper case and a lower case, and the upper case and the lower case may be respectively made of a multilayered porous film composed of a first resin layer, a metal layer and a second resin layer.

In this case, the first resin layer forming an innermost surface of the pouch film may be made of a resin with a thermal bonding property so that the upper case and the lower case may be easily fused to each other when heat is applied thereto in a state where the upper case and the lower case are in contact.

The pouch case <NUM> may be classified into two portions, namely an accommodation portion 12a for accommodating the electrode assembly <NUM> and a sealing portion 12b extending in a circumferential direction of the accommodation portion 12a so that the electrode leads <NUM>, <NUM> drawn to the outside is thermally fused thereto to seal the pouch case <NUM>.

As described above, in the sealing portion 12b, a region where the electrode leads <NUM>, <NUM> pass may have weak sealing, and thus the sealants <NUM>, <NUM> are applied to the corresponding region.

In other words, the sealants <NUM>, <NUM> are interposed between the inner surfaces of the upper pouch case and the lower pouch case in a state of being attached to the peripheries of the electrode leads <NUM>, <NUM>.

Meanwhile, the battery cell <NUM> employed at the present disclosure further includes a sensing lead <NUM> for voltage sensing, in addition to the pair of electrode leads <NUM>, <NUM>. The sensing lead <NUM> may have positive polarity or negative polarity.

In other words, the sensing lead <NUM> is located to be adjacent to any one of the positive electrode lead <NUM> and the negative electrode lead <NUM>. Here, if the sensing lead <NUM> is located on the sealing portion 12b provided in a side where the positive electrode lead <NUM> is drawn as shown in <FIG>, the sensing lead <NUM> has negative polarity, and if the sensing lead <NUM> is located in a side where the negative electrode lead <NUM> contrary to <FIG>, the sensing lead <NUM> has positive polarity.

Next, the sensing lead <NUM> will be described in more detail with reference to <FIG>.

<FIG> is a plane view showing a battery cell employed at the present disclosure, and <FIG> is an enlarged view showing a portion A of <FIG>. Also, <FIG> is a diagram showing an example of the battery cell employed at the present disclosure and is a cross-sectioned view, taken along the line X-X' of <FIG>.

Referring to <FIG>, the sensing lead <NUM> is a component located at the sealing portion 12b at one side or the other side of the battery cell <NUM>. The sensing lead <NUM> is bonded to the electrode tab 11a of the electrode assembly <NUM> and extends in parallel to the positive electrode lead <NUM> or the negative electrode lead <NUM> adjacent thereto. However, the sensing lead <NUM> does not extend to the outside of the pouch case <NUM> but is located at the inside thereof, and is exposed to the outside through a sensing hole H formed in a part of the sealing portion 12b of the pouch case <NUM>.

Meanwhile, as shown in <FIG>, in the sealing portion 12b, a region where the sensing lead <NUM> is located is not sealed. In other words, compared to the entire width D of the sealing portion 12b, a sealing width D of the region where the sensing lead <NUM> is located is smaller. Here, in order to prevent the sealing property from deteriorating due to the smaller width, the sealing width D of the region where the sensing lead <NUM> is located is preferably <NUM>/<NUM> or above of the entire width of the sealing portion 12b.

Next, a method for connecting a sensing wire to the battery cell according to an embodiment of the present disclosure will be described with reference to <FIG>.

<FIG> is a diagram showing that a sensing wire is connected to the battery cell depicted in <FIG>.

<FIG> is a diagram showing an embodiment in which a gasket is applied to the battery cell depicted in <FIG>.

First, referring to <FIG> and <FIG>, if the sensing hole H is formed only in any one surface of the sealing portion 12b, the sensing wire <NUM> may be bonded to the sensing lead <NUM> by using a solder S.

Even though the figures of the present disclosure depict only a case where the sensing hole H is formed in the upper surface of the pouch case <NUM>, the present disclosure is not limited thereto, and the sensing hole H may be formed in the lower surface thereof, instead of the upper surface, if necessary.

Next, referring to <FIG>, the battery cell <NUM> employed at the present disclosure may further include a gasket <NUM> for preventing the sealing property of the pouch case <NUM> from deteriorating due to the sensing hole H.

The gasket <NUM> is inserted into an edge of the sensing hole H and is interposed between the sensing lead <NUM> and the inner surface of the pouch case <NUM> to seal a region where the sensing hole H is formed.

In addition, the gasket <NUM> covers the inner wall of the sensing hole H to prevent the metal layer from being exposed to the outside through the inner wall of the sensing hole H, namely a cut surface for forming the sensing hole H, thereby preventing the occurrence of short circuit by the metal layer.

Next, another example of the battery cell employed at the present disclosure and a method for connecting a sensing wire and a sensing lead will be described with reference to <FIG>.

<FIG> is a diagram showing another example of the battery cell employed at the present disclosure and is a cross-sectioned view, taken along the line X-X' of <FIG>, and <FIG> is a diagram showing that a sensing wire is connected to the battery cell depicted in <FIG>. Also, <FIG> is a diagram showing an embodiment in which a gasket is applied to the battery cell depicted in <FIG>.

First, referring to <FIG>, the battery cell <NUM> employed at the present disclosure may have the sensing hole H in both of the upper and lower surfaces of the pouch case <NUM>, different from <FIG>.

Referring to <FIG>, if the sensing hole H is formed in both of the upper and lower surfaces of the pouch case <NUM> as described above, the sensing wire <NUM> and the sensing lead <NUM> may be electrically connected by using a receptacle <NUM>.

The receptacle <NUM> is connected to one end of the sensing wire <NUM>, and a pair of contact portions 31a formed at the end elastically press both surfaces of the sensing lead <NUM> so that the battery cell <NUM> and the voltage sensor <NUM> may be electrically connected in a stable and convenient way. In this case, in order to minimize electric resistance and maximize the coupling force, the contact portion 31a may be shaped and sized to correspond to the sensing hole H.

Meanwhile, referring to <FIG>, the sensing holes H formed in both surfaces of the pouch case <NUM> may be sealed by the gasket <NUM>, similar to the embodiment depicted in <FIG>.

As described above, since the battery module according to an embodiment of the present disclosure includes the sensing lead <NUM> exposed to the outside through the sealing portion 12b, it is not needed to respectively connect the sensing wire <NUM> to the electrode leads <NUM>, <NUM> drawn in opposite directions.

In other words, the battery module according to an embodiment of the present disclosure is configured such that the battery cell <NUM> and the voltage sensor <NUM> are electrically connected through the sensing lead <NUM> and one electrode lead located adjacent to one side of the battery cell <NUM>, and thus has a structural advantage in that the extending length of the sensing wire <NUM> may be shortened.

Claim 1:
A battery cell (<NUM>), comprising:
an electrode assembly (<NUM>) having a pair of electrode tabs (11a);
a pair of electrode leads (<NUM>, <NUM>) connected to the electrode tabs (11a); and
a pouch case (<NUM>) configured to accommodate the electrode assembly (<NUM>),
wherein the pouch case (<NUM>) is sealed in a state where the electrode leads (<NUM>, <NUM>) are exposed to the outside of the pouch case (<NUM>),
wherein the pouch case (<NUM>) comprises an accommodation portion (12a) for accommodating the electrode assembly (<NUM>) and a sealing portion (<NUM>) extending in a circumferential direction of the accommodation portion (12a),
wherein the battery cell (<NUM>) is a bidirectional drawing-type battery cell in which the pair of electrode leads (<NUM>, <NUM>) are drawn in opposite directions,
wherein the battery cell (<NUM>) includes a sensing lead (<NUM>) connected to one of the electrode tabs (11a), wherein the sensing lead (<NUM>) is located at the sealing portion (12b) at one side or the other side of the battery cell (<NUM>), and
characterized in that the sensing lead (<NUM>) extends in parallel to any one of the pair of electrode leads (<NUM>, <NUM>) adjacent thereto, wherein the sensing lead (<NUM>) is located to be adjacent to any one of the pair of electrode leads (<NUM>, <NUM>) having opposite polarity than the sensing lead (<NUM>), and
wherein the sensing lead (<NUM>) does not extend to the outside of the pouch case (<NUM>) but is located at the inside thereof, and is exposed to the outside through a sensing hole (H) formed in the sealing portion (12b) of the pouch case (<NUM>), wherein the sensing hole (H) is formed in at least one of upper and lower surfaces of the pouch case (<NUM>).