Patent Description:
The present disclosure relates to a battery module, and a battery pack and a vehicle including the same, and more particularly, to a battery module capable of increasing life expectancy, and a battery pack and a vehicle including the battery module.

As the development and demand for mobile devices has increased, the demand for secondary batteries as energy sources has rapidly increased. Nickel cadmium batteries or hydrogen ion batteries have been used as conventional secondary batteries, but recently, lithium secondary batteries having little memory effect compared to nickel-based secondary batteries, free charging and discharging, a very low self-discharge rate, and high energy density have been widely used.

A lithium secondary battery mainly uses a lithium-based oxide and a carbon material as a positive electrode active material and a negative electrode active material. A lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate to which a positive electrode active material and a negative electrode active material are respectively applied are located with a separator therebetween, and a casing in which the electrode assembly is air-tightly accommodated with an electrolyte, that is, a battery case.

A lithium secondary battery includes a positive electrode, a negative electrode, a separator located between the positive electrode and the negative electrode, and an electrolyte, and is divided into a lithium-ion battery (LIB), a polymer lithium-ion battery (PLIB), and the like according to which of a positive electrode active material and a negative electrode active material is used. In general, an electrode of a lithium secondary battery is formed by applying a positive electrode or negative electrode active material to a current collector such as an aluminum or copper sheet, a mesh, a film, or a foil and then drying the same. Various types of secondary batteries include a case for protecting a battery cell, a battery module in which a plurality of battery cells are stacked and inserted into the case, and a battery pack in which a plurality of battery modules are included.

Battery cells may be electrically connected to one another through a bus bar that is a conductor. In general, a positive electrode lead is formed of an aluminum material, a negative electrode lead is formed of a copper material, and a bus bar is also formed of a copper material.

When battery cells provided in a battery module are continuously used, heat is generated from the battery cells and thus, the battery cells are cooled in various ways. For example, an exhaust fan may be provided, and air may be moved by the exhaust fan to cool the battery cells.

However, when a length of a duct coupled to a conventional exhaust fan is increased, battery cells located far from the exhaust fan are not well cooled compared to battery cells located close to the exhaust fan, and thus, lifetimes of the battery cells are different, thereby lowering a lifetime of a battery module.

Document <CIT> discusses a battery pack that can realize heat dissipation and temperature reduction, so as to prolong the service life of the battery pack. Document <CIT> discusses a cooling structure of a secondary battery module constructed by connecting a plurality of unit batteries. Document <CIT> relates to a battery-pack-cooling device. Document <CIT> relates to a cooling structure for a secondary battery module having a plurality of unit batteries. Document <CIT> discusses systems for cooling batteries for cordless power tools.

The present disclosure is designed to solve the problems of the related art, and therefore the present disclosure is directed to providing a battery module capable of increasing life expectancy by minimizing a temperature difference between battery cells through uniform cooling, regardless of positions of the battery cells, and a battery pack and a vehicle including the battery module.

According to an aspect of the present disclosure, there is provided a battery module including: a battery cell stack in which a plurality of battery cells are stacked; a case in which the battery cell stack is accommodated; an air circulation duct located between the battery cell stacks and having a plurality of holes formed therein; and an exhaust fan coupled to a side of the air circulation duct, wherein the plurality of holes of the air circulation duct have different sizes.

A plurality of battery cell stacks are arranged in at least two rows and at least two columns, and the air circulation duct is located between the plurality of battery cell stacks.

The plurality of holes of the air circulation duct are provided so that a hole closest to the exhaust fan is has a smallest size and a size of the hole increases away from the exhaust fan.

The plurality of battery cells are surrounded by an upper end plate, a lower end plate, and a side end plate, and an air inlet is formed in the side end plate, wherein an air cooling plate having a hollow portion in which air may flow is located between the plurality of battery cells, wherein the air inlet of the side end plate and the hollow portion of the air cooling plate are provided at a same height.

At least one partition wall may be formed in the hollow portion of the air cooling plate.

A plurality of partition walls may be arranged at equal intervals.

The case may include an upper cover, a side cover, and a lower cover, wherein the side cover is removed from a portion where the air inlet is located so that the air inlet is exposed to outside.

An air passage may be formed in the upper cover, wherein air moving through the air passage toward the battery cell stack passes through the air inlet and moves to the air circulation duct.

According to another aspect of the present disclosure, there are provided a battery pack and a vehicle including the battery module.

According to embodiments of the present disclosure, life expectancy may be increased by minimizing a temperature difference between battery cells through uniform cooling regardless of positions of the battery cells by changing an overall structure.

The size of each element or a specific portion of the element shown in the drawings may be exaggerated, omitted or schematically drawn for the purpose of convenience and clarity of explanation. Accordingly, the size of each element may not substantially reflect its actual size. While describing the present disclosure, detailed descriptions of related well-known functions or configurations that may blur the points of the present disclosure are omitted.

Also, in the present specification, it will be understood that when elements are "connected" or "coupled" to each other, the elements may be directly connected or coupled to each other, or may be indirectly connected or coupled to each other with an intervening element therebetween.

<FIG> is a perspective view illustrating a battery module according to an embodiment of the present disclosure. <FIG> is an exploded perspective view illustrating a battery module according to an embodiment of the present disclosure. <FIG> is a plan view illustrating a battery cell stack, an air circulation duct, and an exhaust fan which are separated in a battery module according to an embodiment of the present disclosure. <FIG> is a perspective view illustrating an air circulation duct in a battery module according to an embodiment of the present disclosure. <FIG> is a view viewed in an arrow direction A of <FIG>. <FIG> is a view illustrating an air circulation duct and an exhaust fan which are separated in a battery module according to an embodiment of the present disclosure. <FIG> is a cross-sectional view illustrating an air cooling plate located between battery cells in a battery module according to an embodiment of the present disclosure. <FIG> is a side view illustrating an air inlet formed in a side end plate in a battery module according to an embodiment of the present disclosure.

Referring to <FIG>, a battery module <NUM> according to an embodiment of the present disclosure includes a battery cell stack <NUM>, a case <NUM>, an air circulation duct <NUM>, and an exhaust fan <NUM>.

In the battery cell stack <NUM>, a plurality of battery cells <NUM> provided with electrode leads are stacked. Referring to <FIG>, the plurality of battery cell stacks <NUM> are arranged in at least two rows and at least two columns.

The electrode lead provided in the battery cell <NUM> may be a terminal externally exposed to be connected to an external device and may be formed of a conductive material.

The electrode leads may include a positive electrode lead and a negative electrode lead. The positive electrode lead and the negative electrode lead may be arranged in opposite directions in a longitudinal direction of the battery cell <NUM>, or the positive electrode lead and the negative electrode lead may be arranged in the same direction in the longitudinal direction of the battery cell <NUM>.

The positive electrode lead and the negative electrode lead may be formed of various materials. For example, the positive electrode lead may be formed of an aluminum material and the negative electrode lead may be formed of a copper material.

The electrode leads may be electrically connected by a bus bar (not shown). The battery cell <NUM> may have a structure in which a plurality of unit cells arranged in an order of positive electrode plate-separator-negative electrode plate or bi-cells arranged in an order of positive electrode plate-separator-negative electrode plate-separator-positive electrode plate-separator-negative electrode plate are stacked according to battery capacity.

In the battery cell stack <NUM>, a plurality of battery cells <NUM> may be stacked. The battery cell <NUM> may have any of various structures, and also, the plurality of battery cells <NUM> may be stacked in any of various ways.

The battery cell stack <NUM> may include a plurality of cartridges (not shown) in which the battery cells <NUM> are respectively accommodated. Each of the cartridges (not shown) may be manufactured by using plastic injection molding, and the plurality of cartridges (not shown) having a receiving portion in which the battery cell <NUM> may be accommodated may be stacked.

A cartridge assembly in which the plurality of cartridges (not shown) are stacked may include a connector element or a terminal element. The connector element may include, for example, any of various types of electrical connection components or connection members to be connected to a battery management system (BMS) for providing data about a voltage or a temperature of the battery cell <NUM>.

Also, the terminal element may include a positive electrode terminal and a negative electrode terminal as a main terminal connected to the battery cell <NUM>, and the terminal element may include a terminal bolt and may be electrically connected to the outside. The battery cell <NUM> may have any of various shapes.

Referring to <FIG> and <FIG>, the battery cell stack <NUM> or the cartridge assembly in which the battery cell stack <NUM> is accommodated is accommodated in the case <NUM>. For example, the case <NUM> may surround the battery cell stack <NUM>.

The case <NUM> entirely surrounds the battery cell stack <NUM> or a plurality of cartridge assemblies, and thus, protects the battery cell stack <NUM> or the cartridge assembly from external vibration or impact.

The case <NUM> may have a shape corresponding to a shape of the battery cell stack <NUM> or the cartridge assembly. For example, when the battery cell stack <NUM> or the cartridge assembly has a hexahedral shape, the case <NUM> may also have a corresponding hexahedral shape.

Referring to <FIG> and <FIG>, the case <NUM> may include an upper cover <NUM>, a side cover <NUM>, and a lower cover <NUM>. As described below, an air inlet <NUM> may be formed in a side end plate <NUM> surrounding the battery cells <NUM>, and the side cover <NUM> of the case <NUM> is removed from a portion where the air inlet <NUM> of the side end plate <NUM> is located so that the air inlet <NUM> is exposed to the outside.

Due to this structure, air may smoothly move through the air inlet <NUM> of the side end plate <NUM> toward the battery cells <NUM>.

An air passage <NUM> may be formed in the upper cover <NUM>, and air moving through the air passage <NUM> to the battery cell stack <NUM> passes through the air inlet <NUM> and moves to the air circulation duct <NUM>, to cool the battery cells <NUM>, which will be described below in detail with reference to <FIG>.

The case <NUM> may be manufactured by, for example, bending a plate formed of a metal material, or may be manufactured by plastic injection molding. The case <NUM> may be manufactured as an integrated type, or may be manufactured as a separated type.

A through-portion (not shown) through which the connector element or the terminal element may be exposed to the outside may be formed in the case <NUM>. That is, the connector element or the terminal element may be electrically connected to a certain external component or member, and the through-portion may be formed in the case <NUM> so that the electrical connection is not disturbed by the case <NUM>.

Referring to <FIG> together, the air circulation duct <NUM> is located between the plurality of battery cell stacks <NUM>, and a plurality of holes <NUM> are formed in the air circulation duct <NUM>.

Referring to <FIG>, the holes <NUM> of the air circulation duct <NUM> have different sizes. For example, as shown in <FIG>, from among the holes <NUM> of the air circulation duct <NUM>, a hole 310a closest to the exhaust fan <NUM> has a smallest size, a size of the hole <NUM> increases away from the exhaust fan <NUM>, and a hole 310b farthest from the exhaust fan <NUM> has a largest size.

As such, as a size of the hole <NUM> of the air circulation duct <NUM> increases away from the exhaust fan, a large amount of air may be introduced at one time into the battery cells <NUM> located far from the exhaust fan <NUM>.

That is, because a large amount of air is introduced at one time into the battery cells far from the exhaust fan to sufficiently cool the battery cells far from the exhaust fan, a temperature difference between the battery cells <NUM> may be minimized, thereby increasing life expectancy.

The exhaust fan <NUM> is coupled to only a side of the air circulation duct <NUM>, and air outside the case <NUM> is introduced into the case <NUM> and then circulates to cool the battery cells <NUM>.

The exhaust fan <NUM> is coupled to only an end portion, instead of both end portions, of the air circulation duct <NUM>. Referring to <FIG>, a rear side of the air circulation duct <NUM> is blocked.

The exhaust fan <NUM> may be provided in various ways, and includes various types of fans capable of circulating air.

Referring to <FIG>, the plurality of battery cells <NUM> may be protected by an end plate <NUM>. The end plate <NUM> may include an upper end plate <NUM>, a lower end plate <NUM>, and the side end plate <NUM>, and the plurality of battery cells <NUM> may be surrounded by the upper end plate <NUM>, the lower end plate <NUM>, and the side end plate <NUM>. The air inlet <NUM> is formed in the side end plate <NUM>.

Referring to <FIG>, an air cooling plate <NUM> may be located between the plurality of battery cells <NUM>.

A plurality of air cooling plates <NUM> may be provided, and the plurality of air cooling plates <NUM> may be located between the plurality of battery cells <NUM>. That is, the plurality of air cooling plates <NUM> are respectively located between the plurality of battery cells <NUM>.

Referring to <FIG>, a hollow portion <NUM> is formed in the air cooling plate <NUM> so that a fluid flows. That is, air moves along the hollow portion <NUM> in the air cooling plate <NUM>, to cool the battery cells <NUM> contacting the air cooling plate <NUM>. Accordingly, heat may be dissipated from each of the plurality of battery cells <NUM>.

Also, the air cooling plate <NUM> is provided to have a preset stiffness not to be deformed even when the battery cell <NUM> swells.

During charging and discharging, gas may be generated in the battery cell <NUM> and the battery cell <NUM> may swell.

Because the air cooling plate <NUM> is located between the plurality of battery cells <NUM>, if a stiffness of the air cooling plate <NUM> is weak, when the battery cells <NUM> swell, the air cooling plate <NUM> may be pressed and deformed to narrow the hollow portion <NUM> formed in the air cooling plate <NUM>, thereby narrowing a passage through which air may move and reducing heat dissipation effect.

Accordingly, the air cooling plate <NUM> should have a stiffness in a preset range not to be deformed even when the battery cell <NUM> swells. The range of stiffness of the air cooling plate <NUM> may be experimentally determined.

At least one partition wall <NUM> may be formed in the hollow portion <NUM> in the air cooling plate <NUM> so that even when the battery cell <NUM> swells, the air cooling plate <NUM> is not deformed and the hollow portion <NUM> through which air passes is maintained.

A plurality of partition walls <NUM> may be arranged at equal intervals. As such, due to the partition walls <NUM> that are arranged at equal intervals, even when the battery cell <NUM> swells, a shape of the hollow portion <NUM> of the air cooling plate <NUM> may be maintained, and thus, cooling performance may be maintained even during the swelling of the battery cell <NUM>.

The air cooling plate <NUM> may be formed of a metal material having thermal conductivity, for example, an aluminum material having excellent thermal conductivity. However, a material of the air cooling plate <NUM> is not limited to aluminum.

Referring to <FIG>, the air cooling plate <NUM> contacts only one surface of the battery cell <NUM>, by considering a total height of the battery cell stack <NUM>. However, the air cooling plate <NUM> may be provided to contact both surfaces of the battery cell <NUM>.

Referring to <FIG>, the air inlet <NUM> of the side end plate <NUM> and the hollow portion <NUM> of the air cooling plate <NUM> may be provided at the same height. In this case, air introduced through the air inlet <NUM> of the side end plate <NUM> moves through the hollow portion <NUM> of the air cooling plate <NUM> to cool the battery cells <NUM>, moves from the air cooling plate <NUM> to the air circulation duct <NUM>, and then is discharged through the exhaust fan <NUM>.

<FIG> is a view illustrating a movement of air in the battery module <NUM> according to an embodiment of the present disclosure.

An operation and effect of the battery module <NUM> according to an embodiment of the present disclosure will be described with reference to the drawings.

Referring to <FIG> and <FIG>, in the battery module <NUM> according to an embodiment of the present disclosure, the side cover <NUM> of the case <NUM> may be removed from a portion where the air inlet <NUM> of the side end plate <NUM> is located so that the air inlet <NUM> of the side end plate <NUM> is exposed to the outside.

Referring to <FIG>, the air inlet <NUM> of the side end plate <NUM> and the hollow portion <NUM> of the air cooling plate <NUM> may be provided at the same height.

Referring to <FIG>, when the exhaust fan <NUM> operates, air introduced through the air inlet <NUM> of the side end plate <NUM> (see an arrow direction a of <FIG>) moves through the hollow portion <NUM> of the air cooling plate <NUM> to cool the battery cells <NUM>, moves from the air cooling plate <NUM> through the holes <NUM> of the air circulation duct <NUM> to the air circulation duct <NUM>, and then is discharged through the exhaust fan <NUM> (see an arrow direction d of <FIG>).

In this case, referring to <FIG>, the holes <NUM> of the air circulation duct <NUM> may be provided so that the hole 310a closest to the exhaust fan <NUM> has a smallest size, a size of the hole <NUM> increases away from the exhaust fan <NUM>, and the hole 310b farthest from the exhaust fan <NUM> has a largest size, and thus, the battery cells <NUM> located far from the exhaust fan <NUM> may also be sufficiently cooled.

As shown in <FIG> and <FIG>, the air passage <NUM> may be formed in the upper cover <NUM>, and air moving through the air passage <NUM> toward the battery cell stack <NUM> (see an arrow direction b of <FIG>) passes through the air inlet <NUM>, moves through the hollow portion <NUM> of the air cooling plate <NUM> to cool the battery cells <NUM>, moves from the air cooling plate <NUM> through the holes <NUM> of the air circulation duct <NUM> to the air circulation duct <NUM> (see an arrow direction c of <FIG>), and then is discharged through the exhaust fan <NUM> (see the arrow direction d of <FIG>).

Due to this structure, the battery module <NUM> according to an embodiment of the present disclosure may easily cool the battery cells <NUM> and minimize a temperature difference between the battery cells <NUM>, thereby increasing life expectancy.

A battery pack (not shown) according to an embodiment of the present disclosure may include one or more battery modules <NUM> according to an embodiment of the present disclosure as described above. Also, in addition to the battery module <NUM>, the battery pack (not shown) may further include a housing for receiving the battery module <NUM>, and various devices for controlling charging and discharging of the battery module <NUM>, for example, a BMS, a current sensor, and a fuse.

A vehicle (not shown) according to an embodiment of the present disclosure may include the battery module <NUM> or a battery pack (not shown), and the battery module <NUM> may be included in the battery pack (not shown). The battery module <NUM> according to an embodiment of the present disclosure may be applied to the vehicle (not shown), for example, a certain vehicle (not shown) provided to use electricity such as an electric vehicle or a hybrid vehicle.

Claim 1:
A battery module (<NUM>) comprising:
a battery cell stack (<NUM>) in which a plurality of battery cells (<NUM>) are stacked;
a case (<NUM>) in which the battery cell stack (<NUM>) is accommodated;
an air circulation duct (<NUM>) located between the battery cell stacks (<NUM>) and having a plurality of holes (<NUM>) formed therein; and
an exhaust fan (<NUM>) coupled to a side of the air circulation duct (<NUM>),
wherein the plurality of holes (<NUM>) of the air circulation duct (<NUM>) have different sizes,
wherein a plurality of battery cell stacks (<NUM>) are arranged in at least two rows and at least two columns, and
the air circulation duct (<NUM>) is located between the plurality of battery cell stacks (<NUM>),
wherein the plurality of holes (<NUM>) of the air circulation duct (<NUM>) are provided so that a hole (310a) closest to the exhaust fan (<NUM>) has a smallest size and a size of the hole (310b) increases away from the exhaust fan (<NUM>),
wherein the plurality of battery cells (<NUM>) are surrounded by an upper end plate (<NUM>), a lower end plate (<NUM>), and a side end plate (<NUM>), and an air inlet (<NUM>) is formed in the side end plate (<NUM>),
wherein an air cooling plate (<NUM>) having a hollow portion (<NUM>) in which air may flow is located between the plurality of battery cells (<NUM>),
wherein the air inlet (<NUM>) of the side end plate (<NUM>) and the hollow portion (<NUM>) of the air cooling plate (<NUM>) are provided at a same height.