Patent Description:
In general, a battery module includes a plurality of battery cells. The battery cell that is an electrode assembly includes a positive electrode and negative electrode collector, a separator, an active material, and an electrolyte to allow repeated charge and discharge by an electrochemical reaction between components.

Here, the battery cell generates heat in a process of charging or discharging. The battery cell may be accelerated in deterioration when the generated heat is not removed, and fired or exploded in some cases.

Typically, the battery cells are cooled by using a heat sink. That is, as a thermal interface material (TIM) is installed between a case for storing the battery cells and the heat sink, the battery cells are indirectly cooled by the heat sink. However, as a distance between the battery cells and the heat sink increases, a cooling efficiency may be degraded.

The present disclosure provides a battery module capable of effectively cooling a plurality of battery cells by using a heat sink.

The present disclosure also provides a battery module capable of restricting or preventing a heat sink from being deformed.

In accordance with an exemplary embodiment, a battery module includes: an outer case having an accommodation space therein; an inner case having a storage space therein and installed in the accommodation space; a plurality of battery cells stored in the storage space; a heat sink disposed in the accommodation space and installed between the inner case and one side wall of the outer case to cool the battery cells; and a pressing part disposed in the accommodation space and having at least a portion installed between the other side wall of the outer case, which is opposite to the one side wall, and the inner case to press the inner case toward the heat sink.

The pressing part may include: a pressing member brought into contact with the inner case to press the inner case; and a plurality of coupling members coupled to the one side wall of the outer case through the other side wall of the outer case, the pressing member, the inner case, and the heat sink. Here, the coupling member may couple the outer case, the pressing member, the inner case, and the heat sink into one body.

The pressing member may have a hollow shape.

The coupling members may be arranged along a circumference of the inner case.

A pressing projection that protrudes toward the inner case may be provided on a surface of the pressing member, which contacts the inner case, and an insertion groove to which the pressing projection may be inserted is defined in a surface of the inner case, which contacts the pressing member.

A cooling projection that protrudes toward the inner case may be provided on a surface of the heat sink, which contacts the inner case, and a through hole through which the cooling projection passes may be defined in a surface of the inner case, which contacts the heat sink.

Each of the cooling projection and the through-hole may be provided in plurality, and the cooling projections may respectively contact the battery cells through the through-holes.

Each of the cooling projection and the through-hole may be provided in plurality, a cooling plate may be installed between the battery cells and a wall of the inner case, and the cooling projections may contact the cooling plate through the through-holes.

Exemplary embodiments can be understood in more detail from the following description taken in conjunction with the accompanying drawings, in which:.

Hereinafter, specific embodiments will be described in detail with reference to the accompanying drawings. The present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. In the figures, the dimensions of layers and regions are exaggerated for clarity of illustration, and like reference numerals refer to like elements throughout.

<FIG> is a view illustrating a structure of a battery module in accordance with an exemplary embodiment, <FIG> is a view illustrating a connection structure of an inner case and a heat sink in accordance with an exemplary embodiment, <FIG> is a view illustrating a connection structure of an inner case and a heat sink in accordance with another exemplary embodiment, and <FIG> is a view illustrating a connection structure of a pressing member and the heat sink in accordance with another exemplary embodiment.

The battery module in accordance with an exemplary embodiment is a device for supplying a power to electronic equipment or an electronic device. Referring to <FIG>, a battery module <NUM> includes an outer case <NUM>, a battery cell <NUM>, an inner case <NUM>, a heat sink <NUM>, and a pressing part <NUM>.

The outer case <NUM> has an accommodation space therein. For example, the outer case <NUM> may have a cuboid box shape. Thus, the inner case <NUM>, the heat sink <NUM>, and the pressing part <NUM> may be accommodated in the accommodation space.

Here, the outer case <NUM> may include an outer case main body in which an opening is formed in at least a portion thereof and an outer case cover formed in the outer case main body to open and close the opening. Thus, the inner case <NUM>, the heat sink <NUM>, and the pressing part <NUM> may be put into the accommodation space through the opening and be installed therein. However, the exemplary embodiment is not limited to the structure and the shape of the outer case <NUM>. For example, the outer case <NUM> may have various structures and shapes.

The battery cell <NUM> may have a cylindrical shape. The battery cell <NUM> may be provided in plurality. The battery cells <NUM> may be stored in the inner case <NUM>. For example, the battery cells <NUM> may be arranged at predetermined positions in the inner case <NUM>.

The inner case <NUM> has a storage space therein for storing the battery cells. For example, the inner case <NUM> may have a cuboid box shape. Thus, the batter cells <NUM> may be stored in the storage space.

Also, the inner case <NUM> may have a volume less than an internal volume of the outer case <NUM>. Thus, the inner case <NUM> may be installed in the accommodation space of the outer case <NUM>. The inner case <NUM> may be spaced apart from an inner wall of the outer case <NUM>.

Here, the inner case <NUM> may include an inner case main body in which an opening is formed in at least a portion thereof and an inner case cover formed in the inner case main body to open and close the opening. Thus, the battery cells <NUM> may be put into the storage space through the opening and be installed therein. However, the exemplary embodiment is not limited to the structure and the shape of the inner case <NUM>. For example, the inner case <NUM> may have various structures and shapes.

The heat sink <NUM> is disposed in the accommodation space of the outer case <NUM>. The heat sink <NUM> may be installed between the inner case <NUM> and one side wall of the outer case <NUM>. For example, an upper portion of the heat sink <NUM> may contact a lower portion of the inner case <NUM>, and a lower portion of the heat sink <NUM> may contact an inner bottom surface of the outer case <NUM>.

Here, a separate thermal interface material (TIM) may not be installed between the inner case <NUM> and the heat sink <NUM>. Thus, as a distance between the battery cells <NUM> and the heat sink <NUM> decreases, the heat sink <NUM> may effectively cool the battery cells <NUM>.

Also, a flow path through which a refrigerant flows may be formed in the heat sink <NUM>. For example, the refrigerant may be a coolant. The refrigerant may absorb heat from the battery cells <NUM> while passing through the flow path of the heat sink <NUM>. Thus, the heat sink <NUM> may cool the battery cells <NUM>.

Here, a top surface of the heat sink <NUM> may have an area equal to or greater than that of a bottom surface of the inner case <NUM>. Thus, since the heat sink <NUM> may contact the entire bottom surface of the inner case <NUM>, the heat sink <NUM> may easily cool all of the battery cells <NUM> stored in the inner case <NUM>.

Also, the heat sink <NUM> may be made of a material having a high thermal conductivity. For example, the heat sink <NUM> may be made of aluminum or an aluminum alloy material. Thus, the heat sink <NUM> may easily absorb heat generated from the battery cells <NUM>.

As illustrated in <FIG>, the heat sink <NUM> may include a cooling projection <NUM>. The cooling projection <NUM> may protrude from a surface (or top surface) of the heat sink <NUM>, which contacts the inner case <NUM>, toward the inner case <NUM> (or in an upward direction). For example, the cooling projection <NUM> may have a cylindrical shape. However, the exemplary embodiment is not limited to the shape of the cooling projection <NUM>. For example, the cooling projection <NUM> may have various shapes.

Here, as illustrated in (a) of <FIG>, a through-hole <NUM> through which the cooling projection <NUM> passes may be defined in a surface (or bottom surface) of the inner case <NUM>, which contacts the heat sink <NUM>. The cooling projection <NUM> may have a vertical length equal to or greater than that of the through hole <NUM>. Thus, the cooling projection <NUM> of the heat sink <NUM> may directly contact the battery cell <NUM> in the inner case <NUM> through the through-hole <NUM>. Thus, the heat sink <NUM> may further effectively cool the battery cell <NUM>.

Also, the cooling projection <NUM> may be provided in plurality. The plurality of through-holes <NUM> may be provided as many as the number of the cooling projections <NUM>. For example, each of the cooling projections <NUM> and the through-holes <NUM> may be provided as many as the number of the battery cells <NUM>. Each of the cooling projections <NUM> and the through-holes <NUM> may be respectively arranged corresponding to positions of the battery cells <NUM>. Thus, as illustrated in (b) of <FIG>, the cooling projections <NUM> may pass the through-holes <NUM> and directly contact the battery cells <NUM>, respectively. Thus, as the number of the battery cells <NUM> directly contacting the cooling projections <NUM> increases, the battery cells <NUM> may be further effectively cooled. However, the exemplary embodiment is not limited to the structure and the material of the heat sink <NUM> and the number of the cooling projections <NUM>.

Here, when the cooling projections <NUM> are inserted into the through-holes <NUM>, the inner case <NUM> and the heat sink <NUM> are aligned in position and stably coupled to each other. Thus, the battery module <NUM> may be easily manufactured and maintained.

Also, the battery module <NUM> may further include a cooling plate <NUM> as illustrated in (a) of <FIG>. When the cooling plate <NUM> is provided, the cooling projections <NUM> may contact the cooling plate <NUM> instead of directly contacting the battery cells <NUM> as illustrated in (b) of <FIG>. The cooling plate <NUM> may have an area less than that of the storage space of the inner case <NUM>. Thus, the cooling plate <NUM> may be disposed in the storage space of the inner case <NUM>. The cooling plate <NUM> may be installed between the battery cells and a wall of the inner case <NUM>.

Also, the cooling plate <NUM> may be formed along a shape of a circumference of the storage space of the inner case <NUM>. For example, the cooling plate <NUM> may have a rectangular plate shape. The cooling plate <NUM> may have a top surface contacting all of the battery cells <NUM> and a bottom surface contacting the cooling projections <NUM>. That is, the cooling projections <NUM> may pass the through-holes <NUM> and directly contact the cooling plate <NUM> in the inner case <NUM>. Thus, the cooling plate <NUM> may absorb heat generated from all of the battery cells <NUM>, and the heat sink <NUM> may absorb heat of the cooling plate <NUM>. Thus, although the number of the cooling projections <NUM> is less than that of the battery cells <NUM>, or the cooling projections <NUM> and the battery cells <NUM> are not aligned in position, the heat sink <NUM> may easily absorb the heat of all of the battery cells <NUM> through the cooling plate <NUM>.

Here, the cooling plate <NUM> may be made of a material having a high thermal conductivity. For example, the cooling plate <NUM> may be made of aluminum or an aluminum alloy material. Thus, the cooling plate <NUM> may easily transfer the heat generated from the battery cells <NUM> to the heat sink <NUM>. However, the exemplary embodiment is not limited to the shape and the material of the cooling plate <NUM>. For example, the cooling plate <NUM> may have various shapes and include various materials.

The pressing part <NUM> is disposed in the accommodation space of the outer case <NUM>. The pressing part <NUM> may be installed between the inner case <NUM> and the other side wall (or an upper wall) of the outer case <NUM>, which is opposite to one side wall (or a lower wall) of the outer case <NUM>. The pressing part <NUM> may press the inner case <NUM> toward the heat sink <NUM> (or in a downward direction), so that the inner case <NUM> closely contacts the heat sink <NUM>. The pressing part <NUM> includes a pressing member <NUM> and a coupling member <NUM>.

The pressing member <NUM> may be formed along a shape of a circumference of the inner case <NUM>. The pressing member <NUM> has an upper portion contacting an inner ceiling surface of the outer case <NUM> and a lower portion contacting an upper portion of the inner case <NUM>. Thus, the pressing member <NUM> is disposed at an opposite side of the heat sink <NUM> with the inner case <NUM> therebetween. Thus, the pressing member <NUM>, the inner case <NUM>, and the heat sink <NUM> may be arranged in a row along a vertical direction in the accommodation space of the outer case <NUM>.

Here, a bottom surface of the pressing member <NUM> may have an area equal to or greater than that of a top surface of the inner case <NUM>. Thus, since the heat sink <NUM> may contact the entire top surface of the inner case <NUM>, the pressing member <NUM> may uniformly press the entire top surface of the inner case <NUM> in the downward direction. Thus, the entire inner case <NUM> may uniformly and closely contact the heat sink <NUM>.

Also, the pressing member <NUM> may be made of a material having a high thermal conductivity. For example, the pressing member <NUM> may be made of aluminum or an aluminum alloy material. Thus, the heat generated from the battery cells <NUM> may be transferred to the inner case <NUM>, and the pressing member <NUM> may dissipate the heat of the inner case <NUM>. Thus, as heat generated from upper ends of the battery cells <NUM> is dissipated by the pressing member <NUM>, and lower ends of the battery cells <NUM> are cooled by the heat sink <NUM>, temperature increase of the battery cells <NUM> may be effectively restricted or prevented.

Here, the pressing member may have a hollow shape. That is, the pressing member <NUM> may have a pipe shape having an empty inside when cut into a cross-section. Thus, a weight of the pressing member <NUM> may be reduced. Also, a weight of the battery module <NUM> may be reduced.

Also, since the pressing member <NUM> has the hollow shape, the shape of the pressing member <NUM> may be easily deformed by a force applied from the outside. That is, the pressing member <NUM> may have elasticity. Thus, the pressing member <NUM> may press the heat sink <NUM> with flexibility. Thus, the pressing member <NUM> may stably increase a force of pressing the heat sink <NUM> while preventing or restricting a damage of the pressing member <NUM>.

As illustrated in <FIG>, a pressing projection 151a may be provided on the pressing member <NUM>. The pressing projection 151a may protrude from a surface (or a bottom surface) of the pressing member, which contacts the inner case <NUM>, toward the inner case <NUM> (or in the downward direction). For example, the pressing projection 151a may have a cylindrical shape. However, the exemplary embodiment is not limited to the shape of the pressing projection 151a. For example, the pressing projection 151a may have various shapes.

Here, as illustrated in (a) of <FIG>, an insertion groove <NUM> to which the pressing projection 151a is inserted may be defined in a surface (or a top surface) of the inner case <NUM>, which contacts the pressing member <NUM>. The pressing member <NUM> and the inner case <NUM> may be stably coupled to each other by the pressing projection 151a and the insertion groove <NUM>.

Also, the pressing projection 151a may be provided in plurality. The insertion groove <NUM> may be also provided in plurality as many as the number of the pressing projections 151a. The pressing projections 151a may be respectively inserted to different insertion grooves <NUM>. As illustrated in (b) of <FIG>, the pressing member <NUM> and the inner case <NUM> may be further stably coupled to each other as a contact area of the pressing member <NUM> and the inner case <NUM> increases, and the pressing member <NUM> may further effectively dissipate the heat generated from the battery cells <NUM> through the inner case <NUM>. However, the exemplary embodiment is not limited to the structure and the material of the pressing member151 and the number of the pressing projections 151a.

Here, when the pressing projections 151a are inserted into the insertion grooves <NUM>, the pressing member <NUM> and the inner case <NUM> may be aligned in position. Since the positions of the inner case <NUM> and the heat sink <NUM> are aligned by the cooling projections <NUM> and the through-holes <NUM>, the pressing member <NUM>, the inner case <NUM>, and the heat sink <NUM> may be easily aligned in the vertical direction. Thus, the battery module <NUM> may be easily manufactured and maintained.

The coupling member <NUM> may have a bolt shape. The coupling member <NUM> may adjust a degree in which the pressing member <NUM> presses the inner case <NUM>. When the coupling member <NUM> is tightened, the pressing member <NUM> may further strongly press the inner case <NUM> in the downward direction, and when the coupling member <NUM> is loosened, the force of the pressing member <NUM> for pressing the inner case <NUM> in the downward direction may be weakened.

Also, the coupling member <NUM> may extend in the vertical direction. A vertical length of the coupling member <NUM> may be greater than that of the accommodation space of the outer case <NUM> and less than that of the entire outer case <NUM>. Thus, the coupling member <NUM> may be coupled to one side wall (or a lower wall) of the outer case <NUM> through the other side wall (or an upper wall) of the outer case <NUM>, the pressing member <NUM>, the inner case <NUM>, and the heat sink <NUM>. Thus, the coupling member <NUM> may couple the outer case <NUM>, the pressing member <NUM>, the inner case <NUM>, and the heat sink <NUM> into one body so that the outer case <NUM>, the pressing member <NUM>, the inner case <NUM>, and the heat sink <NUM> are stably coupled.

Here, the coupling member <NUM> may pass through the inner case <NUM> and the heat sink <NUM> while being spaced apart from the battery cells <NUM> and the flow path formed in the heat sink <NUM>. Thus, when the coupling member <NUM> passes, the coupling member <NUM> may not damage the battery cells <NUM> or the flow path.

Also, the coupling member <NUM> may be provided in plurality. The coupling members <NUM> may be arranged along the circumference of the inner case <NUM>. The pressing member <NUM> may uniformly press the entire top surface of the inner case <NUM> in a downward direction, and the inner case <NUM> may uniformly press the entire top surface of the heat sink <NUM> by the pressing member <NUM> in the downward direction.

Here, when a separate thermal interface material (TIM) is not installed between the inner case <NUM> and the heat sink <NUM>, the heat sink <NUM> may be deformed by a hydraulic pressure of the refrigerant because the top surface of the heat sink <NUM> is not uniformly pressed. However, since the entire top surface of the heat sink <NUM> is uniformly pressed as the inner case <NUM> closely contacts the top surface of the heat sink <NUM> by the pressing member <NUM> and the coupling member <NUM>, deformation of the heat sink <NUM> may be restricted or prevented.

Also, the coupling member <NUM> may be made of a material having a high thermal conductivity. For example, the coupling member <NUM> may be made of aluminum or an aluminum alloy material. Thus, the coupling member <NUM> may easily transfer heat of the storage space of the inner case <NUM> to the pressing member <NUM> or the heat sink <NUM>. Here, the battery cells <NUM> stored in the storage space of the inner case <NUM> may be further effectively cooled. However, the exemplary embodiment is not limited to the structure and the material of the coupling member <NUM> and a passing or coupling direction of the coupling member <NUM>. For example, the coupling member <NUM> may have various structures, include various materials, and have various passing or coupling directions.

Hereinafter, a method for manufacturing a battery module <NUM> will be described. The method for manufacturing the battery module <NUM> may include: a process of storing battery cells <NUM> in a storage space of an inner case <NUM>; a process of installing a pressing member <NUM>, an inner case <NUM>, and a heat sink <NUM> in an accommodation space of an outer case <NUM>; and a process of coupling the outer case <NUM>, the pressing member <NUM>, the inner case <NUM>, and the heat sink <NUM> by a coupling member <NUM>.

Here, the battery cells <NUM> may be stored in a storage space of the inner case <NUM>. That is, the battery cells <NUM> may be put into the storage space through an opened portion of an inner case main boy and then arranged at predetermined positions in a standing state. When all of the battery cells <NUM> are stored, an inner case cover may be installed on the inner case main body to block the opened portion of the inner case main body.

Thereafter, the pressing member <NUM>, the inner case <NUM>, and the heat sink <NUM> may be installed in the accommodation space of the outer case <NUM>. That is, the pressing member <NUM>, the inner case <NUM>, and the heat sink <NUM> may be put into the accommodation space through an opened portion of the outer case main body. When all of the pressing member <NUM>, the inner case <NUM>, and the heat sink <NUM> are installed in the accommodation space, an outer case cover may be installed on the outer case main body to block the opened portion of the outer case main body.

Specifically, pressing projections 151a of the pressing member <NUM> may be inserted to insertion grooves <NUM> in a top surface of the inner case <NUM>, and cooling projections <NUM> of the heat sink <NUM> may be inserted to through-holes <NUM> in a bottom surface of the inner case <NUM>. Thus, positions of the pressing member <NUM>, the inner case <NUM>, and the heat sink <NUM> may be arranged in a vertical direction in the accommodation space of the outer case <NUM>.

Here, a separate thermal interface material (TIM) may not be installed between the inner case <NUM> and the heat sink <NUM>. Thus, the heat sink <NUM> may be disposed closer to the battery cells <NUM>. Thus, the heat sink <NUM> may effectively cool the battery cells <NUM>.

The cooling projections <NUM> may pass the through-holes <NUM> and directly contact the battery cells <NUM> stored in the inner case <NUM>. Alternatively, when a cooling plate <NUM> is installed in the inner case <NUM>, the cooling projections <NUM> may pass the through-holes <NUM> and contact the cooling plate <NUM>. Thus, as a distance between the heat sink <NUM> and the battery cells <NUM> decreases, the heat sink <NUM> may be disposed closer to the battery cells <NUM>.

Thereafter, the coupling member <NUM> may couple the outer case <NUM>, the pressing member <NUM>, the inner case <NUM>, and the heat sink <NUM>. That is, the coupling member <NUM> may be coupled to a lower wall of the outer case <NUM> through an upper wall of the outer case <NUM>, the pressing member <NUM>, the inner case <NUM>, and the heat sink <NUM>.

Here, the coupling member <NUM> may pass a position at which the battery cells <NUM> are not disposed in the storage space of the inner case <NUM> and a portion at which a flow path is not formed in the heat sink <NUM>. When the coupling member <NUM> passes the inner case <NUM> or the heat sink <NUM>, the battery cells <NUM> or the flow path may be prevented from being damaged.

Also, a plurality of coupling members <NUM> may be arranged along a circumference of the inner case <NUM>. Thus, the pressing member <NUM> may uniformly press the entire top surface of the inner case <NUM> by the coupling member <NUM> in a downward direction, and the inner case <NUM> may uniformly press the entire top surface of the heat sink <NUM> by the pressing member <NUM> in the downward direction. Thus, as the inner case <NUM> closely contacts the heat sink <NUM>, deformation of the heat sink <NUM> may be restricted or prevented.

Here, a strength of a force of the pressing member <NUM> for pressing the inner case <NUM> in the downward direction may be adjusted by the coupling members <NUM>. For example, when the coupling member <NUM> is tightened downward, the pressing member <NUM> may further strongly press the inner case <NUM> in the downward direction, and when the coupling member <NUM> is loosened upward, the force of the pressing member <NUM> for pressing the inner case <NUM> in the downward direction may be weakened. Thus, a degree in which the inner case <NUM> presses the heat sink <NUM> may be adjusted so that the inner case <NUM> stably and closely contact the heat sink <NUM>.

As described above, a distance between the battery cells <NUM> and the heat sink <NUM> may decrease. Thus, the heat sink <NUM> may absorb heat generated from the battery cells <NUM> at a position close to the battery cells <NUM>. Thus, the battery cells <NUM> may be effectively cooled by using the heat sink <NUM>.

Also, the inner case <NUM> and the heat sink <NUM> may closely contact each other in an overall uniform manner by using the pressing part <NUM>. Thus, deformation of the heat sink <NUM> may be restricted or prevented. Thus, the heat sink <NUM> may have an improved lifespan and durability to stably cool the battery cells <NUM>.

In accordance with the exemplary embodiment, the distance between the battery cells and the heat sink may decrease. Thus, the heat sink may absorb the heat generated from the battery cells at the position close to the battery cells. Thus, the battery cells may be effectively cooled by using the heat sink.

Claim 1:
A battery module (<NUM>) comprising:
an outer case (<NUM>) having an accommodation space therein;
an inner case (<NUM>) having a storage space therein and installed in the accommodation space;
a plurality of battery cells (<NUM>) stored in the storage space;
a heat sink (<NUM>) disposed in the accommodation space and installed between the inner case (<NUM>) and one side wall of the outer case (<NUM>) to cool the battery cells (<NUM>); characterized by
a pressing part (<NUM>) disposed in the accommodation space and having at least a portion installed between the other side wall of the outer case (<NUM>), which is opposite to the one side wall, and the inner case (<NUM>) to press the inner case (<NUM>) toward the heat sink (<NUM>).