KR102383202B1 - Battery module with integrated multi-layer cover - Google Patents

Abstract

Disclosed is a battery module having an integrated multi-cover. A battery module having an integrated multi-cover according to the present invention includes: a battery unit in which a plurality of pouch-type battery cells are overlapped in a horizontal direction; and a hexahedron-shaped protection frame having an inner space for accommodating and protecting the battery unit. The protection frame includes: upper and lower covers which are disposed to support upper and lower surfaces of the battery unit, respectively; front and rear covers to which a plurality of busbars connected to lead tabs of the battery cells are mounted, and which are coupled to the upper and lower covers to respectively support the front and rear surfaces of the battery unit; and a pair of side covers which are coupled to the upper and lower covers, and are composed of multiple structures capable of performing both electrical insulation and heat dissipation functions for the battery unit while contacting and supporting both sides of the battery unit where the swelling phenomenon occurs. According to the present invention, the assembly process of the battery module can be reduced due to integration and simplification on parts of the protection frame, and also, thermal management of the battery unit can be effectively achieved through heat dissipation of the side covers and a cooling system associated therewith.

Description

BATTERY MODULE WITH INTEGRATED MULTI-LAYER COVER}

The present invention relates to a battery module having an integrated multi-cover, and more particularly, a multi-layer capable of integrally performing electrical insulation and heat dissipation functions for the battery unit by contacting and supporting both sides of the battery unit in which the swelling phenomenon occurs. It relates to a battery module provided with a cover.

A secondary battery refers to a battery that can be charged and discharged, unlike a primary battery that cannot be charged. , Electric Vehicle, Energy Storage System) or hybrid vehicle (HEV, Hybrid Electric Vehicle) is used as a power source.

Secondary batteries currently widely used in storage systems (ESS) and electric vehicles (EVs) can be classified into lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel hydride batteries, nickel zinc batteries, and the like. is repeated charging and discharging with an output voltage of approximately 25V to 42V per one unit cell.

Therefore, when higher output voltage and power capacity are required, a battery module is formed by connecting several battery cells in series, or a battery pack is formed by connecting these battery modules again in series or parallel and adding other circuits. do.

That is, the battery module refers to an aggregate in which a plurality of secondary batteries are bundled at the middle and upper ends, and the battery pack refers to a large-scale assembly in which battery modules are assembled again to increase capacity and output.

The number of battery cells included in such a battery pack may be variously increased or decreased according to a required output voltage or power capacity.

At this time, while the battery cells constituting the battery pack are repeatedly charged and discharged, a swelling phenomenon in which the outer skin of the battery cells swells due to various causes such as overcharging or overdischarging, short circuit, and leaving at high temperature. this will happen

Since this swelling phenomenon can lead to safety accidents such as ignition and explosion, as well as shortening the lifespan, reduction of capacity, and performance of the secondary battery, spaced apart battery cells at regular intervals in the battery module unit, or The swelling phenomenon is prevented by arranging a compression pad for pressure support between the battery cells.

On the other hand, when the temperature of a battery cell continuously rises beyond the threshold temperature due to a problem such as a short circuit occurring in some battery cells, a thermal runaway phenomenon in which the temperature rise is propagated to the surrounding battery cells may occur.

This thermal runaway phenomenon, in that it triggers a safety accident such as ignition or explosion of a battery module or battery pack, which is a battery unit with a larger capacity, a structure for suppressing or preventing this is required.

However, the housing of the conventional battery module includes an end plate for a battery module assembly that can prevent a change in the appearance of the battery module due to swelling in Korean Patent Application Laid-Open No. 10-2015-0142790 (published on December 23, 2015) and By manufacturing a frame in the form of a box-type steel plate, such as a 'battery pack including this', it remains at the level of preventing changes in the appearance of the battery module due to swelling or reducing external impact.

Therefore, it not only serves to safely protect battery cells from external shocks or swelling, but also can immediately and effectively suppress or prevent thermal runaway or internal heat generated during charging and discharging that rapidly propagates from one battery cell to another. Structural improvement or improvement is required from various angles in relation to the battery module housing.

Republic of Korea Patent Publication No. 10-2015-0142790 (published date: December 23, 2015)

It is an object of the present invention to integrate and simplify the parts of the protection frame that protects the battery cells from external shocks or swelling, while contacting and supporting both sides of the battery part and performing electrical insulation and heat dissipation functions for the battery part in an integrated way. It is to provide a battery module having an integrated multi-cover.

The above object, a battery unit in which a plurality of pouch-type battery cells are arranged to be overlapped in the transverse direction; and a protective frame in a hexahedral shape having an inner space to accommodate and protect the battery part, the protective frame comprising: upper and lower covers arranged to support upper and lower surfaces of the battery part, respectively; front and rear covers having a plurality of bus bars connected to the lead tabs of the battery cells mounted thereon and coupled to the upper and lower covers to support the front and rear surfaces of the battery unit, respectively; and a pair of side covers coupled to the upper and lower covers by contacting and supporting both sides of the battery unit in which the swelling phenomenon occurs and having a multi-layer structure capable of performing both electrical insulation and heat dissipation functions for the battery unit. It is achieved by a battery module having an integrated multiple cover, characterized in that.

The side cover is formed by embossing and insulating coating on a metal plate having excellent heat dissipation properties, or by injection molding an engineering plastic excellent in insulation, heat resistance, heat dissipation and rigidity to form predetermined reinforcing irregularities. It may include an end plate.

The side cover may include an inner shielding plate integrally molded with the end plate by inserting the end plate positioned outside into the mold and then injecting engineering plastic with excellent insulation, heat resistance, heat dissipation, rigidity and flame retardancy. can

The side cover may include: a plate-shaped division plate interposed between the reinforcing concavo-convex and the shielding plate to form a closed empty space with the reinforcing concavo-convex; and a first phase change material filled in the empty space to reduce a temperature difference between the battery unit and the outside air.

The split plate may be made of a metal material having excellent heat dissipation properties having a hollow therein, and a second phase change material may be filled in the hollow.

According to the present invention, the side cover for contacting and supporting both sides of the battery part in which the swelling phenomenon occurs among the hexahedron-shaped protective frame that accommodates and protects the battery part in which a plurality of pouch-type battery cells are horizontally overlapped is the battery part As it is manufactured as an integrated multi-structure to perform both electrical insulation and heat dissipation functions, the parts of the protection frame are integrated and simplified to reduce the assembly man-hours of the battery module, as well as thermal management of the battery part to prevent heat dissipation of the side cover. And it can be achieved more effectively through the cooling system connected thereto.

1 is a perspective view showing an open state of a battery module having an integrated multi-cover according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view of FIG. 1 .
3 is a cross-sectional view showing the internal structure of a side cover that is an integrated multi-cover constituting the battery module of FIG. 1 .
FIG. 4 is a view showing the manufacturing process of the side cover, which is an integrated multi-cover constituting the battery module of FIG. 1, step by step.
5 is a plan view showing the structure of the battery pack in which the battery module of FIG. 1 is mounted.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in describing the present invention, descriptions of already known functions or configurations will be omitted in order to clarify the gist of the present invention.

1 is a perspective view showing an open state of a battery module having an integrated multi-cover according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of FIG. 1, and FIG. 3 is an integrated multiple constituting the battery module of FIG. It is a cross-sectional view showing the internal structure of the side cover which is a cover, and FIG. 4 is a view showing step-by-step the manufacturing process of the side cover, which is an integrated multi-cover constituting the battery module of FIG. 1, and FIG. 5 is the battery module of FIG. It is a plan view showing the structure of the installed battery pack.

Top (top), bottom (bottom), left and right (side or lateral), front (front, front), rear (back, back), etc., which refer to directions in the description and claims of the invention, etc. are not used for limiting rights For convenience of explanation, it is determined based on the relative positions between the drawings and the configuration, and the three axes may be rotated to correspond to each other and changed, and will follow unless otherwise specifically limited.

The battery module 100 having an integrated multi-cover according to the present invention is a power supply source of a medium and high level that provides a predetermined output voltage and power by connecting a plurality of battery cells 10 in series and in parallel, which constitutes the module. It is an invention devised in order to reduce the assembly man-hours of the module by integrating and simplifying parts, and to make thermal management of the battery unit 110 more effective through heat dissipation of the side covers 150a and 150b.

In order to implement the above functions or actions in detail, the battery module 100 according to an embodiment of the present invention includes a battery unit 110 and a protection frame 120 as shown in FIGS. 1 to 3 . can be included.

Hereinafter, each configuration described above will be described in detail.

First, the battery unit 110 may be configured by stacking a plurality of pouch-type (flat plate-shaped) battery cells 10 so that the flat surfaces are horizontally overlapped to form a predetermined output voltage and power. .

Between the plurality of battery cells 10 constituting the battery unit 110, a material such as polyurethane that prevents external changes due to the swelling phenomenon as described above and protects the battery cells 10 from external impact is used. The formed buffer pad may be interposed.

Here, the battery cell 10 includes a pair of lead tabs 12, which are protruding plate-shaped electrodes that electrically connect the positive and negative plates in the electrolyte, and the respective positive and negative plates to the external bus bar 20, respectively. may be included.

In this case, the lead tabs 12 may be respectively formed on the front and rear sides as shown in FIG.

The battery unit 110 as described above is merely a component in which the well-known and commercialized battery cells 10 are stacked in the transverse direction, and is not related to the gist of the present invention. is to be omitted.

The protection frame 120 is a hexahedral-shaped component having an internal space to accommodate and protect the above-described battery unit 110 from external shocks or a changing external environment, and as shown in FIGS. 1 and 2 , It may be configured to include an upper cover 130a, a lower cover 130b, a pair of side covers 150a and 150b, a front cover 140a and a rear cover 140b, and the like.

The upper cover 130a and the lower cover 130b are plate-shaped components arranged to support the upper and lower surfaces of the battery unit 110, respectively, and the upper and lower surfaces of the protective frame 120 are will form

The upper cover 130a and the lower cover 130b according to the embodiment of the present invention do not attach a separate cooling plate, but heat generated according to the operation of the battery unit 110 by itself, respectively, in the battery unit ( 110), it has excellent thermal conductivity so that it can be transmitted smoothly to the outside from the top and bottom, and it can be manufactured from an aluminum alloy plate, etc.

In addition, the upper cover 130a and the lower cover 130b may be manufactured by injection molding an insulating and heat-resistant synthetic resin using a powder such as a graphene material or aluminum that can implement excellent heat dissipation and rigidity as a filler. there is.

Here, the graphene material is a component to compensate for the insufficient thermal conductivity and rigidity of the heat-resistant synthetic resin. As a next-generation new material, carbon atoms form a hexagonal lattice, that is, a honeycomb structure, and form a two-dimensional planar structure, It is thin and light with a thickness of several nanometers to several tens of micrometers, but is 200 times stronger than steel, has excellent electrical and thermal conductivity, and has excellent physical and chemical properties as well as elasticity.

In addition, in order to reduce the weight of the protective frame 120 and to prepare for electrical shielding of the battery cell 10 and heat of the battery cell 10, the insulating and heat-resistant synthetic resin is PPS (Polyphenylene Sulfide), PEEK (Polyetheretherketone), TPI It may be an engineering plastic including at least one of (Thermoplastic Polyimide), Polyethersulfone (PES), Polyphthalamide (PPA), and Polyetherimide (PEI).

Here, PPS is a heat-resistant resin having excellent mechanical strength, chemical resistance, etc., and having a use temperature of 240° C., and is an engineering plastic mainly used for electrical/mechanical parts requiring heat resistance due to flame-retardant properties.

And PEEK is a heat-resistant resin with excellent chemical and abrasion resistance, and a working temperature of 260°C. Even at a fairly high temperature, there is little change in mechanical strength or rigidity, and it has high utility in that injection molding using a general injection machine is possible. engineering plastics.

TPI is a heat-resistant resin with excellent abrasion resistance, rigidity, creep resistance, and chemical resistance, and a glass transition temperature of 250°C.

PES is a heat-resistant resin with high dimensional stability and excellent flame retardancy and a working temperature of 150 to 160°C.

PPA is a heat-resistant resin having very good chemical resistance, low water absorption, and a use temperature of 185° C.

PEI is an engineering plastic mainly used for new material parts because it has excellent high rigidity, high strength, flame retardancy, dimensional stability and especially electrical properties, and is a heat-resistant resin with a working temperature of 180 ° C., excellent in combustion resistance, rigidity and chemical resistance.

The various heat-resistant resins mentioned above may be used for injection molding of the upper cover 130a and the lower cover 130b by selecting any one or appropriately mixing two or more in order to realize the necessary physical properties, and to enhance cooling performance. It can also be used for injection molding in which a cooling plate made of insulating-coated aluminum is inserted therein.

The front cover 140a and the rear cover 140b are configured to seal the bus bars 20 from outside air so that the plurality of bus bars 20 electrically connected to the above-described lead tabs 12 are not contaminated by external foreign substances. As a plate-shaped component, it supports the front and rear surfaces of the battery unit 110, respectively, and forms the front and rear surfaces of the protection frame 120 in a form coupled to the bracket 142 on which the bus bar 20 is mounted. .

Here, the bracket 142 is disposed to support the front, which is the front side, and the rear, which is the rear side of the battery unit 110, respectively, and is fitted to the above-described upper and lower covers 130a and 130b or coupled by various fastening means such as bolts. As a component to be used, a fixing groove into which the battery cell 10 is inserted may be formed on one surface facing the battery unit 110, and the bus bar 20 is mounted and fixed on the other surface opposite to the one surface on which the fixing groove is formed. A groove may be formed.

The bus bar 20 is electrically connected to the lead tab 12 of the battery cell 10 and is a conductor provided to stably transmit a high voltage output to the outside without loss, and an external circuit (not shown) It can be manufactured in various forms, such as a bent rod shape for electrical connection with the battery cell 10 or a ring shape for parallel connection of the battery cells 10 .

When the bracket 142 is coupled to the upper and lower covers 130a and 130b so that the bus bar 20 is penetrated by the lead tab 12 of the battery cell 10, the bus bar 20 is mounted on the bracket 142 and then the bus The lead tab 12 bent to contact the surface of the bar 20 may be electrically and securely connected to each other by welding or the like.

At this time, although not specifically shown, the adjacent bus bars 20 may be electrically connected to each other through a flexible substrate (not shown) or a circuit board (not shown) installed on the bracket 142 .

The bracket 142 may be manufactured by press-working a metal material having excellent heat dissipation properties, such as aluminum, to form a fixing groove and a seating groove, and then insulating coating.

In the front and rear covers 140a and 140b according to the embodiment of the present invention, in addition to the sealing function as described above, the heat (resistance heat) of the bus bar 20 generated according to the output of the battery unit 110 is removed from the outside. Like the upper and lower covers 130a and 130b described above for the purpose of being smoothly released into the heat and electrically insulating the bus bar 20, a powder such as graphene material or aluminum, which has excellent thermal conductivity and can be rigidly implemented, is used as a filler. It can also be manufactured by injection molding a heat-resistant synthetic resin.

In this case, the heat-resistant synthetic resin forming the front and rear covers 140a and 140b is an engineering plastic, and may include at least one of PPS, PEEK, TPI, PES, PPA, and PEI as described above.

The side covers 150a and 150b have a plate-like configuration with a multi-layer structure that supports both sides of the battery unit 110 in contact with the swelling phenomenon and performs both electrical insulation and heat dissipation functions for the battery unit 110 . is an element

These side covers 150a and 150b are fitted to the above-described upper and lower covers 130a and 130b or are coupled by various fastening means such as bolts to form both side surfaces of the protection frame 120 .

The side covers 150a and 150b according to an embodiment of the present invention have a heat dissipation function that smoothly transfers heat generated in the battery unit 110 to the outside according to charging and discharging, as well as rigidity to suppress the swelling phenomenon and the battery unit. In order to implement the insulating function for 110 in detail, as shown in FIGS. 2 to 4 , it includes an end plate 152 and a shielding plate 154 , or a split plate 156 and a first phase change material. (PM1) may be further included.

The above-described end plate 152 is a plate-shaped component provided to smoothly transfer heat generated according to the operation of the battery unit 110 from both side surfaces of the battery unit 110 to the outside, and is an aluminum alloy having excellent thermal conductivity. It may be made of a plate or the like and disposed outside, that is, outside of the side covers 150a and 150b.

This end plate 152, the reinforcing unevenness 152a protruding in a predetermined shape in order to secure necessary rigidity is formed by embossing, and an insulating coating may be made on the surface for electrical shielding of the battery unit 110. .

In addition, the end plate 152 is injection-molded to form predetermined reinforcing concavities and convexities 152a using an insulating and heat-resistant synthetic resin using a graphene material or aluminum powder as a filler that can implement excellent heat dissipation and rigidity. It may be manufactured by

Here, since the synthetic resin having insulation and heat resistance is the same as the type of engineering plastic described above, a description thereof will be omitted.

The reinforcing unevenness 152a of a predetermined shape formed on the end plate 152 is the end plate ( 152) may be a structure provided to enhance the rigidity.

At this time, on the opposite side of the concave-convex shape protruding to the outside, as shown in FIG. 4 , a concave empty space S1 is formed, and the first phase change material PM1 is filled as will be described later.

The shielding plate 154 contacts and supports and insulates both sides of the battery unit 110, while transferring the heat generated in the battery unit 110 to the above-described end plate 152. Side covers 150a and 150b) It is a plate-shaped component placed on the inside of

This shielding plate 154, as shown in FIG. 4, inserts the pre-fabricated end plate 152 into the mold (lower mold 40) and then molds the mold (upper mold 30), and the insulating property , it is possible to be integrally molded with the end plate 152 by injecting engineering plastic having excellent heat resistance, heat dissipation, rigidity and flame retardancy.

In this case, the engineering plastic used for manufacturing the shielding plate 154 may be a plastic having a composition including at least one of PPS, PES, and PEI in order to implement a particularly required flame retardancy.

The required characteristics related to the shielding plate 154 as described above, and the integration with the end plate 152, suppress the swelling of the battery unit 110, integrate and simplify the components of the protection frame 120, and the battery unit 110. This is to promote efficient thermal management and delay of spread in case of fire in the battery unit 110 .

The split plate 156 is a plate-shaped component provided to form the above-described reinforcing unevenness 152a and the closed empty space S1, and may be made of an aluminum alloy plate having excellent thermal conductivity or the like.

The split plate 156 is pre-fabricated and then, as shown in FIG. 4, the reinforcing unevenness 152a and the shielding plate 154 of the above-described end plate 152 inserted into the mold (lower mold 40). It is interposed therebetween and may be integrated with the end plate 152 and the shielding plate 154 .

In this case, the empty space S1 sealed by the split plate 156 may be filled with the first phase change material PM1 that reduces or buffers the temperature difference between the battery unit 110 and the outside air.

Here, the phase change material is a temperature control material that changes state from solid to liquid and liquid to solid based on a specific temperature range and stores (endothermic) or emits (radiates) heat, respectively, in organic, inorganic or natural systems. It can be prepared to phase change in any intended temperature range using a variety of obtainable vegetable materials.

Among the phase change materials manufactured as described above, the first phase change material PM1 filled in the empty space S1 according to an embodiment of the present invention minimizes the temperature difference between the inside and the outside of the battery module 100 to minimize the battery unit 110 . It may be an organic-based paraffinic wax having a phase change temperature range set to 30°C to 35°C so that the stable operation can be achieved.

Due to the first phase change material PM1 in this temperature range, the temperature of the battery unit 110 is constantly maintained at 30°C to 35°C, which is the upper limit of the optimal operating temperature, for a certain period of time even if the internal or external temperature exceeds 35°C. can be maintained

Meanwhile, the split plate 156 may be made of an aluminum alloy plate having excellent heat dissipation property in which a hollow S2 filled with the second phase change material PM2 is formed.

At this time, the second phase change material PM2 filled in the hollow S2 according to an embodiment of the present invention minimizes the temperature difference between the inside and the outside of the battery module 100 so that the battery unit 110 can be stably operated. , the phase change temperature range may be an organic-based paraffinic wax set to 15 ℃ to 20 ℃.

Due to the second phase change material PM2 in this temperature range, the temperature of the battery unit 110 is maintained at 15°C to 20°C, which is the lower limit of the optimal operating temperature, for a certain period of time even if the internal or external temperature is lower than 15°C. can be maintained

As described above, when the first and second phase change materials PM1 and PM2 are simultaneously applied to the side covers 150a and 150b of the present invention, the battery pack 1 as shown in FIG. 5 , the battery unit 110 ), it is not significantly affected by heat generated by the operation or external temperature, and the ideal and optimal operating temperature of 15°C to 35°C is constantly maintained, and power can be transmitted stably.

Furthermore, when the heat that is thermally buffered and continuously emitted from the side covers 150a and 150b is quickly and consistently discharged along the ventilation path 3 by the cooling system 2 provided in the battery pack 1, Thermal management of the battery unit 110 can be performed more efficiently.

In the foregoing, specific embodiments of the present invention have been described and illustrated, but it is common knowledge in the art that the present invention is not limited to the described embodiments, and that various modifications and variations can be made without departing from the spirit and scope of the present invention. It is self-evident to those who have Accordingly, such modifications or variations should not be individually understood from the spirit or point of view of the present invention, and modified embodiments should be said to belong to the claims of the present invention.

1: battery pack
2: Cooling system
3: Blowing path of cooling system
10: battery cell
12: lead tab
20: bus bar
30, 40: upper mold, lower mold
100: battery module having an integrated multiple cover
110: battery unit
120: protection frame
130a, 130b: upper cover, lower cover
140a, 140b: front cover, rear cover
142: bracket
150a, 150b: side cover
152: end plate
152a: reinforcing concavo-convex
PM1: first phase change material
154: shielding plate
156: split plate
S1: empty space
S2: hollow
PM2: second phase change material

Claims (5)

a battery unit in which a plurality of pouch-type battery cells are horizontally overlapped; And as a battery module comprising a protective frame in the shape of a hexahedron having an inner space to accommodate and protect the battery unit,
The protection frame,
upper and lower covers disposed to support the upper and lower surfaces of the battery unit, respectively; a front and rear cover having a plurality of bus bars connected to the lead tab of the battery cell mounted thereon and coupled to the upper and lower covers to support the front and rear surfaces of the battery unit, respectively; and a pair of side covers coupled to the upper and lower covers by contacting and supporting both sides of the battery part in which the swelling phenomenon occurs, and having a multi-layer structure capable of performing both electrical insulation and heat dissipation functions for the battery part. do,
The side cover,
a plate-shaped end plate with predetermined reinforcing irregularities;
an inner shielding plate integral with the end plate positioned outside;
a plate-shaped division plate interposed between the reinforcing concavo-convex and the shielding plate to form a closed empty space with the reinforcing concavo-convex; and
In order to reduce the temperature difference between the battery unit and the outside air, including a first phase change material filled in the empty space,
The split plate is
It is made of a metal material with excellent heat dissipation with a hollow inside,
A battery module having an integrated multi-cover, characterized in that the hollow is filled with a second phase change material. According to claim 1,
The end plate is
It is made by embossing the reinforcing unevenness on a metal plate with excellent heat dissipation and insulating coating,
A battery module having an integrated multi-cover, characterized in that it is formed by injection molding an engineering plastic having excellent insulation, heat resistance, heat dissipation and rigidity to form the reinforcing unevenness. 3. The method of claim 2,
The shielding plate,
After inserting the end plate into a mold, engineering plastic having excellent insulation, heat resistance, heat dissipation, rigidity and flame retardancy is injected and integrally molded with the end plate.
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