Patent Description:
Since a battery pack is used in various fields such as electric vehicles and also applied to transportation means or mobile devices, the environment to which the battery pack is applied may involve consistent transfer of shock to the battery pack. In addition, heat generated in the battery pack itself or heat received from surrounding environment may cause explosion of the battery pack.

A battery module is formed of a plurality of battery cells, and a plurality of battery modules may be embedded in the battery pack. This structure may be for safe, efficient management of a large number of battery cells.

In case of simultaneous ignition of the plurality of battery modules embedded in the battery pack, a strong explosion may occur, leading to a serious accident.

Therefore, there is a need for prevention of an accident in the battery pack in advance or minimization of the extent of accident by blocking or delaying shock transfer such as heat or vibration among the battery modules embedded in the battery pack.

Examples of background art can be found in <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, and <CIT>.

The present disclosure relates to a battery pack and may provide a battery pack for preventing or reducing explosion by minimizing shock and heat transfer among a plurality of battery modules embedded therein.

Technical objects to be achieved by the present disclosure are not limited to the technical problems mentioned above, and other technical objects not mentioned will be clearly understood from the description below by those of ordinary skill in the art to which the present disclosure pertains.

A battery pack of example embodiments of the present disclosure includes a first battery module and a second battery module aligned along a first direction; a crush beam unit provided between the first battery module and the second battery module; and a housing accommodating the first battery module, the second battery module, and the crush beam unit therein, wherein the crush beam unit includes a first heat insulation pad facing the first battery module and a second heat insulation pad facing the second battery module.

According to a battery pack of example embodiments of the present disclosure, it is possible to inhibit transfer of shock and heat among battery modules by providing a crush beam having a heat insulation pad between the battery modules. Thus, even if a single battery module is heated up or explodes, it is possible to prevent or delay chain explosions of surrounding battery modules.

A battery pack of example embodiments of the present disclosure is capable of stably operating even in the environment in which heat and vibration are consistently generated.

A battery pack as defined in the independent claim <NUM> includes:.

The first heat insulation pad or the second heat insulation pad include a mica sheet layer and a ceramic paper layer.

In the battery pack of the present disclosure, the first heat insulation pad or the second heat insulation pad may be formed by laminating the ceramic paper layer between the two mica sheet layers.

In the battery pack of the present disclosure, the thickness of the two mica sheet layers may be <NUM> to <NUM>, and the thickness of the ceramic paper layer may be <NUM> to <NUM>.

In the battery pack of the present disclosure, the crush beam unit may include a first frame part having one side to which the first heat insulation pad is attached; and a second frame part having one side facing the other side of the first frame part and the other side to which the second heat insulation pad is attached, and the first frame part and the second frame part may be coupled such that the other side of the first frame part and the one side of the second frame part are spaced apart from each other.

In the battery pack of the present disclosure, when the first direction is a direction perpendicular to a vertical direction and a second direction is perpendicular to the first direction and the vertical direction, the first frame part may include
a first body part formed of a plate which is planar and perpendicular to the first direction; and a pair of first wing parts formed to protrude from both ends of first body part in the second direction, respectively, and the pair of first wing parts may be coupled to an inner surface of the housing.

In the battery pack of the present disclosure, the second frame part may include a second body part formed of a plate which is planar and perpendicular to the first direction, and a pair of second wing parts formed to protrude from both ends of the second body part in the second direction, respectively, an end of the first wing part may be bent in the first direction to form a first coupling region, and the second wing part may be coupled to the first coupling region.

The battery pack of the present disclosure may further include:.

In the battery pack of the present disclosure, one side of the first battery module may be in close contact with the third battery module, the other side of the first battery module may be in close contact with the first heat insulation pad, one side of the second battery module may be in close contact with the second heat insulation pad, and the other side of the second battery module may be in close contact with the fourth battery module.

The battery pack of the present disclosure may further include a crush layer stacked on upper ends of the first battery module and the third battery module, and the fifth battery module and the sixth battery module may be stacked on an upper surface of the crush layer.

In the battery pack of the present disclosure, the crush layer may include a first layer having an upper surface coupled to lower ends of the fifth battery module and the sixth battery module, and a second layer having a lower surface coupled to upper ends of the first battery module and the third battery module, and the first layer and the second layer may be coupled in a state where a lower surface of the first layer and an upper surface of the second layer are spaced apart from each other.

In the battery pack of the present disclosure, the first frame part may further include a support part protruding from an upper end of the first body part, and the support part may be coupled with the crush layer.

Hereinafter, an example embodiment according to the present disclosure will be described in detail with reference to the accompanying drawings. Here, the size or shape of components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, terms specifically defined in consideration of the configuration and operation of the present disclosure may vary depending on the intention or custom of a user or operator. Definitions of these terms should be made based on the context throughout this specification.

In the description of the present disclosure, it should be noted that orientation or positional relationships indicated by the terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", "one side", and "the other side" are based on orientation or positional relationships shown in the drawings or orientation or positional relationships usually of disposition when a product according to the present disclosure is used, are merely for the description and brief illustration of the present disclosure, and should not be construed as limiting the present disclosure because they are not suggesting or implying that the indicated device or element must be configured or operated in the specified orientation.

<FIG> is a schematic diagram illustrating a battery pack of an example embodiment of the present disclosure. <FIG> is a perspective view illustrating a crush beam unit. <FIG> is a perspective view illustrating a first heat insulation pad <NUM>. <FIG> is a cross-sectional view taken along a line A-A of <FIG>. <FIG> is a schematic diagram illustrating a battery pack of another example embodiment of the present disclosure. <FIG> is a cross-sectional view taken along a line B-B of <FIG>. <FIG> is a graph illustrating temperature of each battery module over time in a battery pack without the first heat insulation pad <NUM> and a second heat insulation pad <NUM>. <FIG> is a graph illustrating temperature of each battery module over time in a battery pack with the first heat insulation pad <NUM> and the second heat insulation pad <NUM>.

Hereinafter, the battery pack of an example embodiment of the present disclosure will be described in detail with reference to <FIG>.

Referring to <FIG> and <FIG>, the battery pack of an example embodiment of the present disclosure includes.

The battery module may be a bundle of a predetermined number of battery cells put in a frame in order to protect the battery cells from external shock, heat, and vibration.

The battery cell is a basic unit of a battery to be used by charging or discharging electrical energy, and may be manufactured by accommodating a positive electrode, a negative electrode, a separator, and an electrolyte in a battery case.

A battery pack may be the final form of a battery system mounted on an electric vehicle. The battery pack may include various control and protection systems such as a battery management system (BMS) and a cooling system along with a plurality of battery modules.

The battery pack of an example embodiment of the present disclosure may include a plurality of battery modules which are accommodated in the housing <NUM> while being aligned along the first direction. When one of the aligned battery modules is referred to as the first battery module <NUM> and a battery module adjacent to the first battery module <NUM> is referred to as the second battery module <NUM>, the crush beam unit <NUM> having the first heat insulation pad <NUM> and the second heat insulation pad <NUM> may be inserted between the first battery module <NUM> and the second battery module <NUM>.

The first direction may be an x-axis direction in <FIG>. A second direction to be described later may be a y-axis direction in <FIG>, and a vertical direction may be a z-axis direction. In the battery pack of the present disclosure, the battery cell may be provided in a planar shape perpendicular to the first direction, and a plurality of battery cells may be embedded in a stacked form along the first direction in the battery module such that surfaces of the respective battery cells face each other. The crush beam unit <NUM> may be disposed between a plurality of the battery modules provided along the first direction to mitigate the shock.

As shown in <FIG>, the first heat insulation pad <NUM> or the second heat insulation pad <NUM> include a mica sheet layer <NUM> and a ceramic paper layer <NUM>.

Mica sheet is a sheet having electrical insulation and heat resistance, is usable in a temperature of about <NUM>, and may stand heat up to approximately <NUM>.

The ceramic paper layer <NUM> may be formed in a paper form through addition of a binder to ceramic fibers (e.g., superwool bulk fiber). The ceramic fiber may include a mixture of CaO and MgO and SiO<NUM>. More specifically, the ceramic paper layer <NUM> may include <NUM> to <NUM> wt% of the mixture of CaO and MgO and <NUM> to <NUM> wt% of SiO<NUM> based on the total weight.

As shown in <FIG>, the first heat insulation pad <NUM> or the second heat insulation pad <NUM> may be formed by laminating the ceramic paper layer <NUM> between the two mica sheet layers <NUM>. In this case, the thickness of the two mica sheet layers <NUM> may be <NUM> to <NUM>, and that of the ceramic paper layer <NUM> may be <NUM> to <NUM>. For example, the mica sheet layer <NUM> may be formed to have a thickness of <NUM>, and the ceramic paper layer <NUM> may be formed to have a thickness of <NUM>. With the laminated structure as described above, it is possible to absorb swing and tolerance of the battery module. The mica sheet layer <NUM> blocks, as an insulating material, disallowed electrical connections between adjacent structures and may support the ceramic paper layer <NUM> to maintain a constant shape due to relatively high rigidity. The ceramic paper layer <NUM> exhibits, as a heat insulating material, an insulation effect which increases as the thickness increases. However, the thickness may be determined in consideration of structural conditions.

As shown in <FIG> and <FIG>, the crush beam unit <NUM> may further include:.

In other words, the first frame part <NUM> may be in close contact with a side of the first battery module <NUM> with the first heat insulation pad <NUM> interposed therebetween, and the second frame part <NUM> may be in close contact with a side of the second battery module <NUM> with the second heat insulation pad <NUM> interposed therebetween.

The first frame part <NUM> and the second frame part <NUM> may be coupled such that the other side of the first frame part <NUM> and the one side of the second frame part <NUM> are spaced apart from each other. Between the other side of the first frame part <NUM> and the one side of the second frame part <NUM>, a supporting means for maintaining a distance between the two surfaces may be provided. However, the entire space between the two surfaces is not completely filled. Owing to the structure above, it is possible to minimize the transfer of heat generated in a single battery module to another battery module along the structure of the crush beam unit <NUM>.

As shown in <FIG>, when the first direction is perpendicular to the vertical direction and a direction perpendicular to the first direction and the vertical direction is referred to as the second direction, the first frame part <NUM> may include a first body part <NUM> formed of a plate which is planar and perpendicular to the first direction, and a pair of first wing parts <NUM> formed to protrude from both ends of first body part <NUM> in the second direction, respectively, and the pair of first wing parts <NUM> may be coupled to an inner surface of the housing <NUM>. In other words, each of the first wing parts <NUM> is formed at each of both edges of the first body part <NUM>, and the first wing parts may be fixed to the housing <NUM>, thereby preventing the crush beam unit <NUM> from swinging inside the housing <NUM>.

The second frame part <NUM> may include a second body part <NUM> formed of a plate which is planar and perpendicular to the first direction and a pair of second wing parts <NUM> formed to protrude from both ends of the second body part <NUM> in the second direction, respectively.

An end of the first wing part <NUM> may be bent in the first direction to form a first coupling region 212a, and the second wing part <NUM> may be coupled to the first coupling region 212a.

An outer surface of the first coupling region 212a formed by bending the first wing part <NUM> may be coupled to the inner surface of the housing <NUM>, and the second wing part <NUM> of the second frame part <NUM> may be coupled to the first coupling region 212a. An end of the second wing part <NUM> may be also bent to be formed as a second coupling region 222a (see <FIG>), and the second coupling region 222a may be coupled to the first coupling region 212a.

As shown in <FIG> and <FIG>, the first heat insulation pad <NUM> may be coupled to the first body part <NUM>, and the second heat insulation pad <NUM> may be coupled to the second body part <NUM>. A first concave part <NUM> may be formed in a partial region of the first body part <NUM> facing the first heat insulation pad <NUM>, and a second concave part <NUM> may be formed in a partial region of the second body part <NUM> facing the second heat insulation pad <NUM>. The first concave part <NUM> and the second concave part <NUM> may be formed at positions facing each other. The other side of the first concave part <NUM> and the other side of the second concave part <NUM> may play a role as a support to help the first frame part <NUM> and the second frame part <NUM> supported in a state of being spaced apart from each other by a predetermined distance when the first frame part <NUM> and the second frame part <NUM> are coupled to each other. In addition, the first concave part <NUM> and the second concave part <NUM> may increase the heat insulation effect by minimizing the area at which the first heat insulation pad <NUM> and the second heat insulation pad <NUM> come in contact with the first body part <NUM> and the second body part <NUM>.

As shown in <FIG>, the battery pack of an example embodiment of the present disclosure may include at least six battery modules. Specifically, the battery pack of an example embodiment of the present disclosure may further include a third battery module <NUM> and a fourth battery module <NUM> aligned along the first direction together with the first battery module <NUM> and the second battery module <NUM>; a fifth battery module <NUM> positioned on the first battery module <NUM>; and a sixth battery module <NUM> positioned on the third battery module <NUM>. In other words, in the battery pack of an example embodiment of the present disclosure, a plurality of battery modules may be arranged in a two-layer structure. The first battery module <NUM>, the second battery module <NUM>, the third battery module <NUM>, and the fourth battery module <NUM> may be disposed in the lower layer, and the fifth battery module <NUM> and the sixth battery module <NUM> may be disposed in the upper layer.

Specifically, the first battery module <NUM>, the second battery module <NUM>, the third battery module <NUM>, the fourth battery module <NUM>, and the crush beam unit <NUM> may be disposed in the lower layer, so that one side of the first battery module is in close contact with the third battery module <NUM>, the other side of the first battery module is in close contact with the first heat insulation pad <NUM>, one side of the second battery module is in close contact with the second heat insulation pad <NUM>, and the other side of the second battery module is in close contact with the fourth battery module <NUM>. In other words, inside the housing <NUM> of the battery pack of an example embodiment of the present disclosure, the third battery module <NUM>, the first battery module <NUM>, the crush beam unit <NUM>, the second battery module <NUM>, and the fourth battery modules <NUM> may be disposed in order along the first direction in the lower layer.

As shown in <FIG>, the battery pack of an example embodiment of the present disclosure may further include a crush layer <NUM> stacked on upper ends of the first battery module <NUM> and the third battery module <NUM>, and the fifth battery module <NUM> and the sixth battery module <NUM> may be stacked on an upper surface of the crush layer <NUM>.

As shown in <FIG> and <FIG>, the crush layer <NUM> may include a first layer <NUM> having an upper surface coupled to lower ends of the fifth battery module <NUM> and the sixth battery module <NUM>, and a second layer <NUM> having a lower surface coupled to upper ends of the first battery module <NUM> and the third battery module <NUM>, wherein the first layer <NUM> and the second layer <NUM> may be coupled in a state where a lower surface of the first layer <NUM> and an upper surface of the second layer <NUM> are spaced apart from each other. The first frame part <NUM> may further include a support part <NUM> protruding from an upper end of the first body part <NUM>, and the support part <NUM> may be coupled with the crush layer <NUM>. Transfer of vibration and heat among layers may be reduced by the crush layer <NUM>.

<FIG> and <FIG> are graphs illustrating changes in temperature of each battery module over time in a situation with an explosion taken place in the first battery module <NUM>.

<FIG> is a graph indicating temperature of each battery module over time in the battery pack without the first heat insulation pad <NUM> and the second heat insulation pad <NUM>. In <FIG>, a graph indicating the temperature of the first battery module <NUM> is M3-<NUM>, and a graph indicating the temperature of the second battery module <NUM> is M2-<NUM>. The temperature gradually increased in the second battery module <NUM> without a rapid change in the temperature before about <NUM> minutes, but a rapid change in the temperature may be observed after about <NUM> minutes. As can be seen in the graph of <FIG>, the structural features of the crush beam unit <NUM> delay heat transfer.

<FIG> is a graph illustrating temperature of each battery module over time in the battery pack with the first heat insulation pad <NUM> and the second heat insulation pad <NUM>. In <FIG>, a graph indicating the temperature of the first battery module <NUM> is M3, and a graph indicating the temperature of the second battery module <NUM> is M2. Referring to <FIG>, the explosion was delayed longer than <NUM> minutes when the first heat insulation pad <NUM> and the second heat insulation pad <NUM> were provided. In other words, it can be seen that the first heat insulation pad <NUM> and the second heat insulation pad <NUM> further maximize the heat transfer delay effect of the crush beam unit <NUM>.

Although the example embodiments according to the present disclosure have been described above, these are merely exemplary, and the invention is defined in the appended claims.

Claim 1:
A battery pack comprising:
a first battery module (<NUM>) and a second battery module (<NUM>) aligned along a first direction (x-axis);
a crush beam unit (<NUM>) provided between the first battery module (<NUM>) and the second battery module (<NUM>); and
a housing (<NUM>) configured to accommodate the first battery module (<NUM>), the second battery module (<NUM>), and the crush beam unit (<NUM>) therein,
wherein the crush beam unit (<NUM>) comprises a first heat insulation pad (<NUM>) facing the first battery module (<NUM>) and a second heat insulation pad (<NUM>) facing the second battery module (<NUM>),
characterized in that the first heat insulation pad (<NUM>) or the second heat insulation pad (<NUM>) comprises a mica sheet layer (<NUM>) and a ceramic paper layer (<NUM>).