Patent Description:
The secondary battery is drawing attentions as a new energy source for enhancing energy efficiency and environment friendliness in that the use of fossil fuels can be reduced greatly and no byproduct is generated during energy consumption.

Secondary batteries widely used at the preset include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries and the like. 5V to <NUM>.

Meanwhile, when a plurality of battery cells are connected in series or in parallel to configure a battery pack, it is common to configure a battery module composed of at least one battery cell first, and then configure a battery pack by using at least one battery module and adding other components.

When the battery cell is manufactured, an electrolyte is injected into a battery case that accommodates an electrode assembly. In order to inject the electrolyte, in the conventional battery cell manufacturing process, after a battery cell is disposed in a vacuum chamber of a vacuum state, an electrolyte is injected into the vacuum chamber, and then if the electrolyte is completely injected, the battery case is sealed in the vacuum chamber.

However, for the conventional battery cell, facilities for injecting an electrolyte into the vacuum chamber and sealing the battery case should be provided, and thus its implementation is difficult due to the complicated facilities. This is a major factor that increases the manufacturing cost of the battery cell and decreases the productivity.

In addition, for the conventional battery cell, the battery case should be cut and then sealed again in a vacuum state in order to remove gaseous products.

Moreover, after the conventional battery cell is completely manufactured, it is not possible to inject an additional electrolyte into the battery case or remove gas from the battery case.

Thus, it is required to search for a battery cell which may allow an electrolyte to be easily injected into a battery case thereof and also ensure easy management in the future, and a method for manufacturing the battery cell.

<CIT>, <CIT>, <CIT>, <CIT>, and <CIT> disclose a battery having an injection hole and/or a method for injecting electrolyte into the battery.

Thus, the present disclosure is directed to providing a battery cell which may allow an electrolyte to be easily injected into a battery case thereof and also ensure easy management in the future, and a method for manufacturing the battery cell.

In one aspect of the present disclosure, there is provided a battery cell, comprising: an electrode assembly; a pair of electrode leads electrically connected to the electrode assembly; a battery case configured to accommodate the electrode assembly and expose a portion of the pair of electrode leads to the outside; an electrolyte injection hole formed in the battery case and connectable to an electrolyte injecting device that injects an electrolyte in a vacuum state so that the electrolyte is injected into the battery case; and an injection hole cap configured to cover the electrolyte injection hole and mounted to the electrolyte injection hole so as to be detachable from the electrolyte injection hole by user manipulation.

The injection hole cap may be screwed to the electrolyte injection hole.

The electrolyte injection hole may have an inner hollow for injecting the electrolyte into the battery case and protrude out of the battery case.

The electrolyte injecting device may be inserted into an outer circumference of the electrolyte injection hole when the electrolyte is injected in the vacuum state.

An outer circumference of the electrolyte injection hole and an inner circumference of the injection hole cap may respectively have threads for the screwing.

The electrolyte injection hole may have an inner hollow for injecting the electrolyte into the battery case and protrude to the inside of the battery case.

The electrolyte injecting device may be inserted into an inner circumference of the electrolyte injection hole when the electrolyte is injected in the vacuum state.

An inner circumference of the electrolyte injection hole and an outer circumference of the injection hole cap may respectively have threads for the screwing.

At least one anti-slip groove for preventing a slip during the user manipulation may be formed at an outer circumference of the injection hole cap.

The electrolyte injecting device may include: an injection cylinder connected to the electrolyte injection hole; a vacuum unit provided at the injection cylinder to decompress the inside of the battery case to a vacuum state; and an electrolyte unit provided at the injection cylinder to provide an electrolyte into the battery case.

In one embodiment of the present invention, there is provided a method for injecting an electrolyte of a pouch-type battery cell as defined in the appended claim <NUM>, the method comprising: separating an injection hole cap, which covers an electrolyte injection hole formed in a battery case of a battery cell, according to user manipulation; connecting an electrolyte injecting device to the electrolyte injection hole; decompressing the inside of the battery case to a vacuum state by using the electrolyte injecting device; injecting an electrolyte into the battery case by using the electrolyte injecting device; separating the electrolyte injecting device from the electrolyte injection hole; and mounting the injection hole cap to the electrolyte injection hole according to user manipulation to cover the electrolyte injection hole.

The injection hole cap is screwed to the electrolyte injection hole.

The electrolyte injection hole has an inner hollow for injecting the electrolyte into the battery case and protrudes out of the battery case.

At least one anti-slip groove for preventing a slip during the user manipulation is formed at an outer circumference of the injection hole cap.

According to various embodiments as above, it is possible to provide a battery cell which may allow an electrolyte to be easily injected into a battery case thereof and also ensure easy management in the future, and a method for manufacturing the battery cell.

<FIG> is a diagram for illustrating a battery cell according to an embodiment of the present disclosure, and <FIG> is a cross-sectioned view showing a portion A of the battery cell of <FIG>.

Referring to <FIG> and <FIG>, the battery cell <NUM> may be a pouch-type secondary battery. The battery cell <NUM> may be filled with an electrolyte e (see <FIG>) by using an electrolyte injecting device <NUM>, explained later.

The electrolyte injecting device <NUM> includes an injection cylinder <NUM>, a vacuum unit <NUM> and an electrolyte unit <NUM>.

The injection cylinder <NUM> is mounted to be connected to the inside of the battery cell <NUM> and have a predetermined flow path therein. In detail, the injection cylinder <NUM> is connected to an electrolyte injection hole <NUM>, explained later, and the electrolyte e and the air inside the battery cell <NUM> may flow through the flow path of the injection cylinder <NUM>.

The vacuum unit <NUM> is connected to the injection cylinder <NUM> and may decompress the inside of the battery cell <NUM> to a vacuum state. The vacuum unit <NUM> may suck the air inside the battery cell <NUM> so that the battery cell <NUM> comes into a vacuum state.

The electrolyte unit <NUM> is connected to the injection cylinder <NUM> and may inject the electrolyte e into the battery cell <NUM>. The electrolyte unit <NUM> may supply the electrolyte e to the battery cell <NUM> after the battery cell <NUM> comes into a vacuum state by the vacuum unit <NUM>.

Seeing the battery cell <NUM> again, the battery cell <NUM> may include an electrode assembly <NUM>, a battery case <NUM>, an electrode lead <NUM>, an insulation tape <NUM>, an electrolyte injection hole <NUM> and an injection hole cap <NUM>.

The electrode assembly <NUM> may include a positive electrode plate, a negative electrode plate and a separator. The electrode assembly <NUM> is well known in the art and thus will not be described in detail here.

The battery case <NUM> may be made of a laminate sheet including a resin layer and a metal layer and accommodate the electrode assembly <NUM>. The battery case <NUM> may be filled with the electrolyte e by using the electrolyte injecting device <NUM>.

An edge of the battery case <NUM> exposes a portion of the electrode leads <NUM>, explained later, to the outside and may be sealed to keep the electrode assembly <NUM> and the electrolyte e airtight therein. The sealing process may be performed before or after the electrolyte e is injected by using the electrolyte injecting device <NUM>.

The electrode lead <NUM> is provided in a pair, and the pair of electrode leads <NUM> may include a positive electrode lead and a negative electrode lead. The pair of electrode leads <NUM> is connected to the electrode assembly <NUM> and may protrude out of the battery case <NUM>.

The insulating tape <NUM> may be provided in a number corresponding to the number of the electrode leads <NUM>. In other words, the insulating tape <NUM> may be provided in a pair. The pair of insulating tapes <NUM> may prevent a short circuit between the battery case <NUM> and the electrode lead <NUM> and improve the sealing of the battery edge <NUM>.

The pair of insulation tapes <NUM> may be made of a film having insulation and thermal fusion. For example, the pair of insulation tapes <NUM> may be made of any one material layer (a single layer or a multilayer) selected from polyimide (PI), polypropylene (PP), polyethylene (PE) and polyethylene terephthalate (PET).

The electrolyte injection hole <NUM> is formed at one side of the battery case <NUM> and may be connected to the electrolyte injecting device <NUM> to inject the electrolyte e into the battery case <NUM>. As described above, after being connected to the battery case <NUM>, the electrolyte injecting device <NUM> may decompress the battery case <NUM> to a vacuum state and then inject the electrolyte e into the battery case <NUM>.

The electrolyte injection hole <NUM> has an inner hollow <NUM> for injecting the electrolyte e and protrudes out of the battery case <NUM>. In addition, a thread for screwing with the injection hole cap <NUM>, explained later, may be formed at an outer circumference <NUM> of the electrolyte injection hole <NUM>.

The injection cylinder <NUM> may be inserted into the outer circumference <NUM> of the electrolyte injection hole <NUM> when the electrolyte injecting device <NUM> is mounted. Accordingly, the electrolyte injecting device <NUM> may be mounted to the electrolyte injection hole <NUM> more stably.

The injection hole cap <NUM> covers the electrolyte injection hole <NUM> and may be mounted to the electrolyte injection hole <NUM> so as to be detachable from the electrolyte injection hole <NUM> according to user manipulation.

Accordingly, the injection hole cap <NUM> may open the inside of the battery case <NUM> when being detached from the electrolyte injection hole <NUM> and may seal the inside of the battery case <NUM> when being mounted to the electrolyte injection hole <NUM>.

The injection hole cap <NUM> is screwed to the electrolyte injection hole <NUM> for easy removal and mounting according to user manipulation. For this, a thread corresponding to the thread of the electrolyte injection hole <NUM> may be formed at an inner circumference <NUM> of the injection hole cap <NUM>.

An anti-slip groove <NUM> is formed at an outer circumference <NUM> of the injection hole cap <NUM>. The anti-slip groove <NUM> is used for preventing a slip during the user manipulation and may be formed to have a predetermined length along a length direction (Y-axial direction) of the injection hole cap <NUM>, which is perpendicular to a rotation direction according to the user manipulation. Also, the anti-slip groove <NUM> is provided in plural and spaced apart from each other by a predetermined distance.

Hereinafter, an electrolyte injection process of the battery cell <NUM> will be described in more detail.

<FIG> are diagrams for illustrating that an electrolyte is injected into the battery cell of <FIG>.

Referring to <FIG>, when an electrolyte e (see <FIG>) is injected into the battery cell <NUM> in order to make the battery cell <NUM>, a manufacturer or the like may separate the injection hole cap <NUM> from the electrolyte injection hole <NUM> according to user manipulation to open the battery case <NUM>. Here, the user manipulation may be performed by simply turning the injection hole cap <NUM> for releasing the screwing.

If the injection hole cap <NUM> is separated, the electrolyte injection hole <NUM> exposes the inside of the battery case <NUM> to the outside. If the battery case <NUM> is filled with gas or the like, the gas or the like may also be easily removed from the battery case <NUM> by separating the injection hole cap <NUM>.

Accordingly, in this embodiment, since the gas or the like in the battery case <NUM> may be removed only by separating the injection hole cap <NUM>, a gas pocket cutting process, demanded to manufacture the battery cell <NUM>, and a sealing process required again after the gas pocket cutting process may be omitted.

Referring to <FIG>, after that, the manufacturer or the like may connect the electrolyte injecting device <NUM> to the opened electrolyte injection hole <NUM>. At this time, the electrolyte injecting device <NUM> is inserted to surround the outer circumference <NUM> of the electrolyte injection hole <NUM> and thus may be stably mounted to the electrolyte injection hole <NUM>.

After that, the manufacturer or the like may inject the air inside the battery case <NUM> into the vacuum unit <NUM> through the electrolyte injection hole <NUM> and the injection cylinder <NUM> by using the vacuum unit <NUM> of the electrolyte injecting device <NUM>, so that the inside of the battery case <NUM> is decompressed to a vacuum state.

In this case, the electrolyte e is easily injected into the electrode assembly <NUM> in the vacuum state. In addition, when the electrolyte e is injected into the battery case <NUM>, moisture or foreign substances in the air are prevented from entering the battery case <NUM>.

Referring to <FIG>, if the inside of the battery case <NUM> comes into the vacuum state, the manufacturer or the like may inject the electrolyte e (see <FIG>) into the battery case <NUM> through the electrolyte cylinder <NUM> and the electrolyte injection hole <NUM> by using the electrolyte unit <NUM> of the electrolyte injecting device <NUM>.

Referring to <FIG>, if the electrolyte e is completely injected, the manufacturer or the like may separate the electrolyte injecting device <NUM> from the electrolyte injection hole <NUM>. After that, the manufacturer or the like may mount the injection hole cap <NUM> to the electrolyte injection hole <NUM> again according to user manipulation to seal the inside of the battery case <NUM>. Here, the user manipulation may be performed by simply turning the injection hole cap <NUM> for the screwing.

As described above, in the battery cell <NUM> of this embodiment, it is possible to inject the electrolyte e into the battery case <NUM> more easily or remove the gas inside the battery case <NUM> to the outside easily when the battery cell <NUM> is manufactured using the injection hole cap <NUM> conveniently detachable according to user manipulation and the electrolyte injection hole <NUM> connected to the electrolyte injecting device <NUM>.

In addition, in the battery cell <NUM> of this embodiment, it is possible to inject the electrolyte e into the battery case <NUM> more easily or remove the gas inside the battery case <NUM> to the outside easily not only when the battery cell <NUM> is being manufactured but also at any time after the battery cell <NUM> is manufactured, by means of the detachable injection hole cap <NUM>.

Moreover, in the battery cell <NUM> of this embodiment, the sealing process for sealing the battery case <NUM> may be performed independently at any time before or after the electrolyte e is injected.

Further, as described above, in the battery cell <NUM> of this embodiment, the gas pocket cutting process for the battery cell <NUM> and the sealing process performed after the gas pocket cutting process may be omitted when the battery cell <NUM> is manufactured.

Thus, it is possible to reduce the manufacturing cost of the battery cell <NUM> of this embodiment and significantly increase the productivity of the battery cell <NUM>.

In addition, while the battery cell <NUM> of this embodiment is in use, it is easy to inject the electrolyte e and remove the gas, thereby facilitating easy management of the battery cell <NUM>.

<FIG> are diagrams for illustrating a battery cell, which is not covered by the present invention.

The battery cell <NUM> of this embodiment is substantially identical or similar to the battery cell <NUM> (see <FIG>) in the former embodiment, and thus the same or similar components are not described in detail and just different features will be described in detail.

Referring to <FIG>, the battery cell <NUM> may include an electrode assembly <NUM>, a battery case <NUM>, an electrolyte injection hole <NUM> and an injection hole cap <NUM>. In addition, though not shown in the figures, the battery cell <NUM> of this embodiment may also include the electrode lead <NUM> (see <FIG>) and the insulation tape <NUM> (see <FIG>) of the former embodiment.

The electrode assembly <NUM> and the battery case <NUM> are similar to the electrode assembly <NUM> (see <FIG>) and the battery case <NUM> (see <FIG>) of the former embodiment and thus are not described in detail here.

The electrolyte injection hole <NUM> has an inner hollow for injecting the electrolyte e (see <FIG>) into the battery case <NUM> and may be formed to protrude into the battery case <NUM>.

The electrolyte injecting device <NUM> may be inserted into an inner circumference <NUM> of the electrolyte injection hole <NUM>. Accordingly, the electrolyte injecting device <NUM> may be stably mounted to the electrolyte injection hole <NUM>, and after that, the inside of the battery case <NUM> may be decompressed to a vacuum state by using the vacuum unit <NUM>, and the electrolyte e (see <FIG>) may be injected into the battery case <NUM>.

Meanwhile, the electrolyte injecting device <NUM> further includes a mount cylinder <NUM> as shown in <FIG>. The mount cylinder <NUM> is mounted to a lower side of the injection cylinder <NUM> and supports the injection cylinder <NUM> when the electrolyte injection hole <NUM> of the injection cylinder <NUM> is mounted.

The mount cylinder <NUM> is closely adhered to a surface of the battery case <NUM> when the electrolyte injecting device <NUM> is mounted. The mount cylinder <NUM> may prevent the injection cylinder <NUM> from being twisted or warped and prevent foreign substances from penetrating into the injection cylinder <NUM>.

Meanwhile, the injection cylinder <NUM> is provided to be capable of sliding in a vertical direction of the mount cylinder <NUM>. Accordingly, after the injection cylinder <NUM> completely contacts the surface of the battery case <NUM>, the injection cylinder <NUM> may be mounted to the electrolyte injection hole <NUM> while sliding downwardly. In this case, the injection cylinder <NUM> may be mounted to the electrolyte injection hole <NUM> more tightly and stably.

In addition, the inner circumference <NUM> of the electrolyte injection hole <NUM> may have a thread for screwing with the cap body <NUM> of the injection hole cap <NUM>, explained later, and for releasing the screwing.

The injection hole cap <NUM> may include a cap head <NUM> and a cap body <NUM>.

The cap head <NUM> may cover the electrolyte injection hole <NUM> when the injection hole cap <NUM> is mounted. The cap head <NUM> is formed to have a diameter larger than the diameter of the electrolyte injection hole <NUM>, and when the injection hole cap <NUM> is mounted, the cap head <NUM> come into contact with the battery case <NUM> at an upper side (+Y-axial direction) of the electrolyte injection hole <NUM>.

Accordingly, the cap head <NUM> may seal the electrolyte injection hole <NUM> more reliably when the injection hole cap <NUM> is mounted, thereby more surely preventing foreign substances or the like from penetrating into the electrolyte injection hole <NUM>.

The cap body <NUM> extends downward (-Y-axial direction) from the cap head <NUM> and may be screwed to the inner circumference <NUM> of the electrolyte injection hole <NUM> when the injection hole cap <NUM> is mounted. For this, a thread corresponding to the thread of the electrolyte injection hole <NUM> may be formed at an outer circumference <NUM> of the cap body <NUM>.

<FIG> is a diagram for illustrating a battery cell according to the present disclosure.

The battery cell <NUM> is substantially identical or similar to the battery cell <NUM> (see <FIG>) in the former embodiment, and thus the same or similar components are not described in detail and just different features will be described in detail.

Referring to <FIG>, the battery cell <NUM> may include an electrode assembly <NUM>, a battery case <NUM>, an electrolyte injection hole <NUM> and an injection hole cap <NUM>. Moreover, though not shown in the figures, the battery cell <NUM> of this embodiment may also include the electrode lead <NUM> (see <FIG>) and the insulation tape <NUM> (see <FIG>) of the former embodiment.

The electrolyte injection hole <NUM> may be formed at one side of the battery case <NUM> to have an inner hollow having the same thickness as the battery case <NUM>. A thread for screwing with the injection hole cap <NUM>, explained later, may be formed at an inner circumference <NUM> of the electrolyte injection hole <NUM>.

The cap head <NUM> covers the electrolyte injection hole <NUM> and is formed to have a larger diameter than the inner hollow of the electrolyte injection hole <NUM> so as to contact one side of the battery case <NUM> when the injection hole cap <NUM> is mounted.

The cap body <NUM> may also be detachably mounted to the electrolyte injection hole <NUM>, for example by fitting instead of the screwing. In this case, the process for forming a thread at the cap body <NUM> and the electrolyte injection hole <NUM> may be omitted.

<FIG> is a diagram for illustrating a battery cell according to still further another embodiment of the present disclosure.

Referring to <FIG>, the injection hole cap <NUM> of the battery cell <NUM> may be provided at one side (+X-axial direction) of both sides (X-axial direction) of the battery case <NUM>. In other words, the injection hole cap <NUM> may be formed at one side (+X-axial direction) of the battery case <NUM> where the electrode leads <NUM> are not provided. In addition, the injection hole cap <NUM> may be provided at both sides (X-axial direction), instead of being provided at only one side (+X-axial direction or -X-axial direction). Meanwhile, the electrolyte injection hole not depicted in the figure may be formed at a portion of the battery case <NUM> corresponding to the position of the injection hole cap <NUM>.

<FIG> is a flowchart for illustrating a method for manufacturing a battery cell according to an embodiment of the present disclosure.

Referring to <FIG>, when the electrolyte is injected into the battery cell to manufacture the battery cell, a manufacturer or the like separates the injection hole cap covering the electrolyte injection hole provided at the battery case of the battery cell according to user manipulation (S10). As the injection hole cap is separated, the inside of the battery case may be exposed to the outside.

After that, the manufacturer or the like connects an electrolyte injecting device for injecting an electrolyte into the electrolyte injection hole (S20). At this time, the electrolyte injecting device may be stably fixed as being inserted into the electrolyte injection hole.

If the electrolyte injecting device is completely mounted, the manufacturer or the like decompresses the inside of the battery case to a vacuum state by using the electrolyte injecting device (S30), and then, injects the electrolyte into the battery case by using the electrolyte injecting device (S40).

If the electrolyte is completely injected into the battery case, the manufacturer or the like separates the electrolyte injecting device from the electrolyte injection hole (S50) and mounts the injection hole cap to the electrolyte injection hole again according to user manipulation to cover the electrolyte injection hole (S60).

Claim 1:
A method for injecting an electrolyte of a pouch-type battery cell, comprising:
separating an injection hole cap (<NUM>), which covers an electrolyte injection hole (<NUM>) formed in a battery case (<NUM>) of a battery cell, according to user manipulation;
connecting an injection cylinder (<NUM>) of an electrolyte injecting device (<NUM>) which includes the injection cylinder (<NUM>), a vacuum unit (<NUM>), and an electrolyte unit (<NUM>) to the electrolyte injection hole (<NUM>);
decompressing the inside of the battery case (<NUM>) to a vacuum state by using the electrolyte injecting device (<NUM>);
injecting an electrolyte into the battery case (<NUM>) by using the electrolyte injecting device (<NUM>);
separating the electrolyte injecting device (<NUM>) from the electrolyte injection hole (<NUM>); and
mounting the injection hole cap (<NUM>) to the electrolyte injection hole (<NUM>) according to user manipulation to cover the electrolyte injection hole (<NUM>),
wherein anti-slip grooves (<NUM>) for preventing a slip during the user manipulation are formed at an outer circumference (<NUM>) of the injection hole cap (<NUM>),
wherein the anti-slip grooves (<NUM>) are formed to have a predetermined length along a length direction of the injection hole cap (<NUM>), which is perpendicular to a rotation direction according to the user manipulation, to preventing a slip during the user manipulation,
wherein the user manipulation is performed by turning the injection hole cap (<NUM>) for releasing or mounting the screwing,
wherein the anti-slip grooves (<NUM>) are spaced apart from each other by a predetermined distance,
wherein the injection hole cap (<NUM>) is screwed to the electrolyte injection hole (<NUM>),
wherein the electrolyte injection hole (<NUM>) has an inner hollow for injecting the electrolyte into the battery case (<NUM>) and protrudes out of the battery case (<NUM>),
wherein the electrolyte injecting device (<NUM>) further includes a mount cylinder (<NUM>), the mount cylinder (<NUM>) is mounted to a lower side of the injection cylinder (<NUM>) and supports the injection cylinder (<NUM>) when the electrolyte injection hole (<NUM>) of the injection cylinder (<NUM>) is mounted, and the mount cylinder (<NUM>) is closely adhered to a surface of the battery case when the electrolyte injecting device (<NUM>) is mounted, and
the injection cylinder (<NUM>) is provided to be capable of sliding in a vertical direction of the mount cylinder (<NUM>).