Patent Description:
The present disclosure relates to a battery module and a battery pack including the same, and more particularly, to a battery module with improved temperature deviation between battery cells, and a battery pack including the same.

With the increase of the technological development and demand for a mobile device, the demand for batteries as energy sources is rapidly increasing. In particular, a secondary battery has attracted considerable attention as an energy source for power-driven devices, such as an electric bicycle, an electric vehicle, and a hybrid electric vehicle, as well as an energy source for mobile devices, such as a mobile phone, a digital camera, a laptop computer and a wearable device.

Small-sized mobile devices use one or several battery cells for each device, whereas middle or large-sized devices such as vehicles require high power and large capacity. Therefore, a middle or large-sized battery module having a plurality of battery cells electrically connected to one another is used.

The middle or large-sized battery module is preferably produced so as to have as small a size and weight as possible. Consequently, a prismatic battery, a pouch-shaped battery or the like, which can be stacked with high integration and has a small weight relative to capacity, is usually used as a battery cell of the middle or large-sized battery module. Meanwhile, in order to protect the battery cell stack from external impact, heat or vibration, the battery module may include a module frame of which a front surface and back surface are opened to house the battery cell stack in an internal space.

<FIG> is an exploded perspective view of a conventional battery module. <FIG> is a perspective view showing a state in which components constituting the battery module of <FIG> are combined.

Referring to <FIG> and <FIG>, the conventional battery module <NUM> includes a battery cell stack <NUM> in which a plurality of battery cells <NUM> are stacked in one direction, a module frame <NUM> for housing the battery cell stack <NUM>, end plates <NUM> for covering the front and rear surfaces of the battery cell stack and a busbar frame <NUM> formed between the end plate <NUM> and the front and rear surfaces of the battery cell stack <NUM>. The module frame <NUM> includes a lower frame <NUM> that covers the lower part and both side surfaces of the battery cell stack <NUM> and an upper plate <NUM> that covers the upper surface of the battery cell stack <NUM>. In the battery module <NUM>, a heat conductive resin layer <NUM> is applied to a bottom surface for covering the lower part of the battery cell stack <NUM> in the lower frame <NUM>. The heat conductive resin layer <NUM> can cool the heat generated in the battery cell stack <NUM> while transferring the heat generated in the battery cell stack <NUM> to the outside of the battery module <NUM>.

<FIG> is a cross-sectional view taken along the cutting line A-A of <FIG>. <FIG> is a top view of the bottom surface of the module frame, which is a component of the battery module of <FIG>.

Referring to <FIG>, the conventional battery module <NUM> has a structure for cooling the lower part of the battery cell stack <NUM>, which is a structure in which the heat generated in the battery cells <NUM> flows in the first cooling direction D1 toward the lower part. However, the battery cell stack <NUM> has the feature that the temperature of the central battery cell is the highest and the temperature of the outer battery cell is the lowest. In addition, as the battery cell stack <NUM> is configured such that the positive electrode and the negative electrode are positioned at both end parts based on the longitudinal direction, heat is generated relatively more than the central part in the charging/discharging process of the battery module <NUM>.

In particular, in order to prevent the lithium plating phenomenon, the battery cell <NUM> stops charging/discharging the entire battery module <NUM> when the voltage drops below a predetermined voltage value. At this time, in terms of using the battery module <NUM>, there is no problem even if the central battery cell of the battery cell stack <NUM> is as a reference. However, due to the cooling deviation between the battery cells, the outer battery cells are cooled more than the central battery cells, so that the voltage drop of the outer battery cell is severe, and can therefore be limited in terms of the use of the module.

However, referring to <FIG>, in the case of the conventional battery module <NUM>, the heat conductive resin layer <NUM> is applied to the entire bottom surface of the lower frame <NUM> without considering the characteristics of the temperature deviation of the battery cell stack <NUM>, and thus, a cooling deviation occurs in the battery cell stack <NUM>. In particular, in a low-temperature environment, the heat conductive resin layer <NUM> has a large effect on the cooling of the battery cell stack <NUM>, and the cooling deviation of the battery cell stack <NUM> due to the heat conductive resin layer <NUM> can be formed to be larger than that in a high temperature environment. Therefore, in the conventional battery module <NUM>, the outer battery cells of the battery cell stack <NUM> are limited in terms of the use of the module due to a voltage drop, and there is a need to improve the cooling deviation between the central battery cell and the outer battery cell.

<CIT> provides a battery module, including a battery pack and a heat dissipation unit, the battery pack including a plurality of stacked battery cells, the heat dissipation unit comprising a cooling member and an elastic heat conducting member.

It is an object of the present disclosure to provide a battery module with improved temperature deviation between battery cells, and a battery pack including the same.

The objects of the present disclosure are not limited to the aforementioned objects, and other objects which are not described herein should be clearly understood by those skilled in the art from the following detailed description and accompanying drawings.

According to one embodiment of the present disclosure, there is provided a battery module comprising: a battery cell stack in which a plurality of battery cells are stacked; and a module frame for housing the battery cell stack, wherein a heat conductive resin layer is formed on the bottom surface of the module frame, wherein the heat conductive resin layer includes a first heat conductive resin layer and a second heat conductive resin layer, wherein the first heat conductive resin layer is formed adjacent to the front surface of the battery cell stack, and the second heat conductive resin layer is formed adjacent to the rear surface of the battery cell stack, and wherein at least a part of the first heat conductive resin layer and at least a part of the second heat conductive resin layer are spaced apart from each other.

The first heat conductive resin layer and the second heat conductive resin layer may be formed to have equal width, and at least part of the first heat conductive resin layer and at least part of the second heat conductive resin layer are spaced apart from each other.

A first distance spaced apart between the first heat conductive resin layer and the second heat conductive resin layer differ depending on a position on the bottom surface of the module frame.

The first distance increases from the center of the bottom surface of the module frame toward the outside.

The first heat conductive resin layer and the second heat conductive resin layer formed at a position corresponding to the center of the bottom surface of the module frame are spaced apart from each other.

The first heat conductive resin layer and the second heat conductive resin layer may have shapes symmetrical with each other based on the longitudinal direction of the module frame.

The first heat conductive resin layer and the second heat conductive resin layer may have shapes symmetrical with each other based on the width direction of the module frame.

The first heat conductive resin layer and the second heat conductive resin layer may be composed of the same heat conductive resin material.

The module frame may include a lower frame for housing the lower part and both side surfaces of the battery cell stack, and an upper plate for covering the upper surface of the battery cell stack.

According to another embodiment of the present disclosure, there is provided a battery pack comprising the above-mentioned battery module.

According to embodiments of the present disclosure, a heat conductive resin layer whose length differs depending on the position of the bottom surface of the module frame corresponding to the battery cell stack is formed, thereby capable of improving the temperature deviation between the battery cells.

The effects of the present disclosure are not limited to the effects mentioned above and additional other effects not described above will be clearly understood from the description and the appended claims by those skilled in the art.

Hereinafter, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement them. The present disclosure may be modified in various different ways, and is not limited to the embodiments set forth herein.

Portions that are irrelevant to the description will be omitted to clearly describe the present disclosure, and like reference numerals designate like elements throughout the specification.

Further, in the drawings, the size and thickness of each element are arbitrarily illustrated for convenience of the description, and the present disclosure is not necessarily limited to those illustrated in the drawings. In the drawings, for convenience of the description, the thicknesses of some layers and regions are shown to be exaggerated.

Further, throughout the specification, when a portion is referred to as "including" a certain component, it means that the portion can further include other components, without excluding the other components, unless otherwise stated.

Further, throughout the specification, when referred to as "planar", it means when a target portion is viewed from the upper side, and when referred to as "cross-sectional", it means when a target portion is viewed from the side of a cross section cut vertically.

Below, the battery module according to one embodiment of the present disclosure will be described. However, the description herein is made based on the front surface among the front and rear surfaces of the battery module, without being necessarily limited thereto, and even in the case of the rear surface, a description may be given with the same or similar contents.

<FIG> is an exploded perspective view of a battery module according to one embodiment of the present disclosure. <FIG> is a diagram showing a heat conductive resin layer formed on the bottom surface of the module frame of <FIG>.

Referring to <FIG> and <FIG>, the battery module <NUM> according to the present embodiment includes a battery cell stack <NUM> in which a plurality of battery cells <NUM> are stacked in a first direction (y-axis), a module frame <NUM> that houses the battery cell stack <NUM>, end plates <NUM> that are positioned respectively on the front and rear surfaces of the battery cell stack <NUM>, and a busbar frame <NUM> that is positioned between the battery cell stack <NUM> and the end plate <NUM>. The module frame <NUM> includes a U-shaped frame <NUM> of which an upper surface, a front surface and a rear surface are opened, and an upper plate <NUM> that covers the upper part of the battery cell stack <NUM>.

In the battery module <NUM> according to the present embodiment, a first heat conductive resin layer <NUM> may be positioned between the battery cell stack <NUM> and the bottom surface of the U-shaped frame <NUM>. In the first heat conductive resin layer <NUM>, a heat conductive resin can be applied to the bottom surface of the U-shaped frame <NUM>, before the battery cell stack <NUM> is mounted on the bottom surface of the U-shaped frame <NUM>. Then, as the heat conductive resin is cured, the first heat conductive resin layer <NUM> can be formed. Thereby, the first heat conductive resin layer <NUM> can transfer the heat generated in the battery cell <NUM> to the bottom of the battery module <NUM> to cool the battery cell <NUM>.

Further, referring to <FIG> and <FIG>, the heat conductive resin layer <NUM> includes a first heat conductive resin layer <NUM> and a second heat conductive resin layer <NUM>. Here, the first heat conductive resin layer <NUM> and the second heat conductive resin layer <NUM> may be composed of the same heat conductive resin material.

On the bottom surface of the module frame <NUM>, the first heat conductive resin layer <NUM> is formed adjacent to the front surface of the battery cell stack <NUM>, and the second heat conductive resin layer <NUM> is formed adjacent to the rear surface of the battery cell stack <NUM>. In addition, at least a part of the first heat conductive resin layer <NUM> and at least a part of the second heat conductive resin layer <NUM> may be spaced apart from each other.

In one example, the first heat conductive resin layer <NUM> and the second heat conductive resin layer <NUM> may be spaced apart from each other. At this time, the first heat conductive resin layer <NUM> and the second heat conductive resin layer <NUM> may be formed to have mutually equal or different width. More preferably, the first heat conductive resin layer <NUM> and the second heat conductive resin layer <NUM> may be formed to have mutually equal width. That is, in the battery module <NUM> according to the present embodiment, the heat conductive resin layer <NUM> may be formed based on both end parts of the battery cell stack at the lower surface of the module frame <NUM>.

Consequently, according to the present embodiment, the heat conductive resin layer <NUM> can relatively reduce the degree of cooling for the outer battery cells of the battery cell stack, thereby reducing the cooling deviation within the battery cell stack. In addition, the heat conductive resin layer <NUM> can effectively cool the heat generated as the positive electrode and the negative electrode are positioned at both end parts based on the longitudinal direction of the battery cell stack. Thereby, according to the present embodiment, since the voltage drop of the outer battery cells becomes relatively weak, even if the outer battery cell is used as a reference, there is no limitation in terms of the use of the module, and non-uniform deterioration between battery cells in the module resulting therefrom can be prevented. In addition, the energy efficiency can also be increased.

Further, the heat conductive resin layer <NUM> is configured such that the first heat conductive resin layer <NUM> and the second heat conductive resin layer <NUM> are spaced apart from each other, which is economically advantageous in that the application amount of the heat conductive resin can be reduced and the manufacturing cost is reduced. Further, the first heat conductive resin layer <NUM> and the second heat conductive resin layer <NUM> may have shapes symmetrical with each other based on the longitudinal direction of the module frame <NUM>. Further, the first heat conductive resin layer <NUM> and the second heat conductive resin layer <NUM> may have shapes symmetrical with each other based on the width direction of the module frame <NUM>. Consequently, the heat conductive resin layer <NUM> can be cooled more uniformly with respect to the battery cell stack <NUM>, so that the cooling deviation of the battery module <NUM> can be further improved.

<FIG> and <FIG> are diagrams showing a heat conductive resin layer formed on a bottom surface of a module frame according to another embodiment of the present disclosure.

Referring to <FIG> and <FIG>, in the heat conductive resin layer <NUM>, a first distance spaced apart between the first heat conductive resin layer <NUM> and the second heat conductive resin layer <NUM> may differ depending on the position on the bottom surface of the battery module <NUM>. Other contents are the same as those described above, and the heat conductive resin layer <NUM> will be mainly described below.

Referring to <FIG> and <FIG> , according the present embodiment, a first distance between the first heat conductive resin layer <NUM> and the second heat conductive resin layer <NUM> may increase from the center of the bottom surface of the module frame <NUM> toward the outside. In other words, the width of the first heat conductive resin layer <NUM> and the second heat conductive resin layer <NUM> may decrease from the center of the bottom surface of the module frame <NUM> toward the outside. In one example, the first heat conductive resin layer <NUM> and the second heat conductive resin layer may be in contact with each other at a position corresponding to the center of the bottom surface of the module frame <NUM>. Further, the first heat conductive resin layer <NUM> and the second heat conductive resin layer may be spaced apart from each other at positions corresponding to the center of the bottom surface of the module frame <NUM>.

Thereby, the heat conductive resin layer <NUM> is formed to have a relatively large width at a position corresponding to the central battery cell of the battery cell stack, and may be formed to have a relatively small width at a position corresponding to the outer battery cell of the battery cell stack. That is, in the battery module <NUM> according to the present embodiment, the heat conductive resin layer <NUM> is formed based on the center battery cell of the battery cell stack and both end parts of the battery cell stack at the lower surface of the module frame <NUM>.

Thereby, in the present embodiment, the heat conductive resin layer <NUM> can further reduce the degree of cooling for the outer battery cells of the battery cell stack while maintaining the degree of cooling for the central battery cells of the battery cell stack, thereby further reducing the cooling deviation within the battery cell stack. Consequently, the heat conductive resin layer <NUM> reduces the degree of cooling for the outer battery cells of the battery cell stack while maintaining the degree of cooling for both end parts of the battery cell stack, thereby more efficiently reducing the cooling deviation within the battery cell stack. Therefore, according to the present embodiment, the voltage drop of the outer battery cell is relatively weaker, and even if the outer battery cell is used as a reference, it is not more limited in terms of the use of the module, and non-uniform degradation between the battery cells in the module resulting therefrom can be further prevented. In addition, the energy efficiency can be further increased.

In addition, in the heat conductive resin layer <NUM>, a distance at which the first heat conductive resin layer <NUM> and the second heat conductive resin layer <NUM> is spaced apart depending on the position of the module frame <NUM> is larger, which is economically advantageous in that the application amount of the thermal conductive resin can be further reduced, and the manufacturing cost is further reduced.

The battery pack according to another embodiment of the present disclosure includes the battery module described above. Meanwhile, one or more of the battery modules according to the present embodiment may be packaged in a pack case to form a battery pack.

The above-described battery module and battery pack including the same can be applied to various devices. Such a device may be applied to a vehicle means such as an electric bicycle, an electric vehicle, or a hybrid vehicle, but the present disclosure is not limited thereto, and is applicable to various devices capable of using a battery module, which also falls under the scope of the present disclosure.

Although the invention has been shown and described above with reference to the preferred embodiments, the scope of the present disclosure is not limited thereto.

Claim 1:
A battery module (<NUM>) comprising:
a battery cell stack (<NUM>) in which a plurality of battery cells (<NUM>) are stacked; and
a module frame (<NUM>) for housing the battery cell stack (<NUM>),
wherein a heat conductive resin layer (<NUM>) is formed on the bottom surface of the module frame,
wherein the heat conductive resin layer (<NUM>) comprises a first heat conductive resin layer (<NUM>) and a second heat conductive resin layer (<NUM>),
wherein the first heat conductive resin layer (<NUM>) is formed adjacent to the front surface of the battery cell stack (<NUM>), and the second heat conductive resin layer (<NUM>) is formed adjacent to the rear surface of the battery cell stack (<NUM>), and
wherein at least a part of the first heat conductive resin layer (<NUM>) and at least a part of the second heat conductive resin layer (<NUM>) are spaced apart from each other,
wherein a first distance spaced apart between the first heat conductive resin layer (<NUM>) and the second heat conductive resin layer (<NUM>) differ depending on a position on the bottom surface of the module frame (<NUM>), the first distance increasing from the center of the bottom surface of the module frame (<NUM>) toward the outside,
wherein the first heat conductive resin layer (<NUM>) and the second heat conductive resin layer (<NUM>) formed at a position corresponding to the center of the bottom surface of the module frame are spaced apart from each other.