Patent Description:
In the related art, a battery pack further includes a tray and a sealing cover. A battery module is arranged in an accommodating chamber defined by the tray and the sealing cover. The tray includes a bottom plate and side beams connected around the bottom plate. In order to increase the rigidity and strength of the tray, reinforcing transverse beams and/or longitudinal beams are arranged in the tray. The battery module is fixed to the transverse beams and/or the longitudinal beams by screws or other structural members. Since the batteries and the structural members are scattered inside the battery pack and assembled together by fasteners or adhesion, such a battery pack is not of high integrity at the system level. After the battery pack is installed on a vehicle, the structure of the battery pack alone cannot satisfy the mechanical safety performance at the vehicle level, and the structure of the battery pack needs to be supported and protected by the frame of the vehicle. As a result, compact and light-weight design cannot be achieved for the battery pack and the vehicle at present, resulting in higher overall costs and a complex structural design of the vehicle and the battery pack.

<CIT> discloses a battery apparatus including a housing, a plurality of battery cells housed in the housing, and an adhesive agent which adheres to the battery cells. <CIT> provides a battery device having a stabilizing structure that may resist vibrations. <CIT> relates to a support plate that has substantially the same shape as the plane shape of the inner space of a lower case and that is bonded to the upper surface of plate-like battery cells.

According to the invention a battery pack and a vehicle are provided as set out in the claims.

In order to solve at least one of the technical problems mentioned above, according to a first aspect of the present disclosure, a battery pack is provided. The battery pack includes a cell array and two first reinforcing plates. The cell array includes a number of cells. Each of the cells is defined with a length L, a thickness D, and a height H between the length L and the thickness D. The number of cells are arranged along a thickness direction, and the cells are adhered to each other by a structural adhesive. The two first reinforcing plates are arranged opposite to each other and are respectively adhered to the two surfaces of the cell array along an arrangement direction of the cells, and are configured to constrain relative positions between the cells.

In some implementations of the present disclosure, the two first reinforcing plates are respectively adhered to two opposite surfaces of the cells along a height direction.

In some implementations of the present disclosure, at least one of the cells satisfies: <NUM>≤L≤<NUM>, and <NUM>≤L/D≤<NUM>.

According to the invention, the battery pack includes a number of layers of cell arrays arranged along a height direction of the cells, a partition plate is arranged between two neighboring layers of cell arrays, and the partition plate is fixedly adhered to the cell arrays on two sides of the partition plate.

In some implementations of the present disclosure, a second reinforcing plate is arranged between at least two neighboring cells, and the second reinforcing plate is fixedly adhered to the cells arranged on two sides of the second reinforcing plate.

In some implementations of the present disclosure, the battery pack further includes an upper cover and a tray, the tray includes a bottom plate and a side frame surrounding the bottom plate, the upper cover and the tray are connected to define a cell accommodating chamber, and the cell array is arranged in the cell accommodating chamber.

In some implementations of the present disclosure, the two first reinforcing plates constitute the upper cover and the bottom plate respectively.

In some implementations of the present disclosure, the battery pack further includes a protection plate, and the protection plate is arranged on an outer surface of the bottom plate.

In some implementations of the present disclosure, the protection plate includes two layers of aluminum plates and a steel plate or a foamed aluminum plate sandwiched between the two layers of aluminum plates.

In some implementations of the present disclosure, the protection plate includes two fiber composite layers and a foamed polymer layer sandwiched between the two fiber composite layers, and the fiber composite layer includes a glass fiber layer or a carbon fiber layer.

In some implementations of the present disclosure, outer surfaces of the two first reinforcing plates are respectively adhered to an inner surface of the upper cover and an inner surface of the bottom plate.

In some implementations of the present disclosure, at least one of the bottom plate or the upper cover includes two layers of aluminum plates and a steel plate or a foamed aluminum plate sandwiched between the two layers of aluminum plates.

In some implementations of the present disclosure, at least one of the bottom plate and the upper cover includes two fiber composite layers and a foamed polymer layer sandwiched between the two fiber composite layers, and the fiber composite layer includes a glass fiber layer or a carbon fiber layer.

In some implementations of the present disclosure, the upper cover is provided with a sealing groove at a position corresponding to the side frame, a sealant layer is arranged in the sealing groove, and the upper cover and the tray are hermetically connected by the sealant layer.

In some implementations of the present disclosure, a gap between the cell array and the side frame is filled with a structural adhesive.

In some implementations of the present disclosure, each of the cells includes a first end and a second end arranged opposite to each other along a length direction, the side frame includes a first side frame and a second side frame arranged opposite to each other along the length direction of each of the cells, the first end of each of the cells is supported by the first side frame, and the second end of each of the cells is supported by the second side frame.

In some implementations of the present disclosure, a first support step is arranged on the first side frame, a second support step is arranged on the second side frame, the first end of each of the cells is supported by the first support step, and the second end of each of the cells is supported by the second support step.

In some implementations of the present disclosure, the battery pack further includes a supporting structure, the first end of each of the cells is fitted to and supported by the first side frame through the supporting structure, and/or the second end of the cell is fitted to and supported by the second side frame through the supporting structure.

In some implementations of the present disclosure, the supporting structure includes a first support block, a lower surface of the first end of each of the cells is supported by the first side frame through the first support block, and/or a lower surface of the second end of each of the cells is supported by the second side frame through the first support block.

In some implementations of the present disclosure, the supporting structure includes a second support block, the first end of each of the cells facing the first side frame is fitted to the first side frame through the second support block; and/or the second end of each of the cells facing the second side frame is fitted to the second side frame through the second support block.

In some implementations of the present disclosure, each of the cells includes electrode terminals, the electrode terminals are respectively arranged at the first end and the second end of each of the cells, holes are provided on the supporting structure, and the electrode terminals of each of the cells extend through the holes respectively and are electrically connected by a cell connector.

In some implementations of the present disclosure, the battery pack further includes an insulation partition plate, and the insulation partition plate is arranged between the supporting structure and an inner surface of the side frame.

In some implementations of the present disclosure, the battery pack further includes a third side frame and a fourth side frame arranged opposite to each other along the arrangement direction of the cells, and the third side frame and the fourth side frame are respectively fixedly adhered to each of the cells adjacent thereto.

In some implementations of the present disclosure, a reinforcing beam is arranged on the third side frame and/or the fourth side frame, and the reinforcing beam is configured to limit expansion of the cell array.

In some implementations of the present disclosure, a thickness of the first reinforcing plate is <NUM>-<NUM>.

According to a second aspect of the present disclosure, an electric vehicle is provided, including the battery pack according to any one of the above implementations.

Compared with the prior art, the present disclosure has the following beneficial effects. In the present disclosure, the two first reinforcing plates are arranged on the two opposite surfaces of the cell array along the arrangement direction of the cells, and the two first reinforcing plates are configured to constrain the relative positions between the cells, to eliminate the weak points in the gap between two neighboring cells when the cells are adhered to each other. The two first reinforcing plates and the cell array form a honeycomb-like structure, and thus, the battery pack is designed as an integral structural member of great rigidity. Such a honeycomb-like structure is of strong resistance to instability, high bending rigidity, and a significantly reduced weight. Therefore, the rigidity and strength of the battery pack are greatly enhanced, thereby improving the mechanical safety and reliability. When in use, the structural strength of the integral battery pack provides part of the structural strength of the vehicle. The battery pack can be used to enhance the structural strength of the vehicle, and the battery pack does not need to be protected by the vehicle. Such a design allows for the simplification or even removal of the structure designed for the frame of the vehicle to protect the structural strength of the battery pack, and meets the requirements for a lightweight design of the vehicle, thereby reducing the manufacturing costs and improving the efficiency of vehicle production.

As shown in <FIG>, the present disclosure provides a battery pack <NUM>, including a cell array <NUM> and two first reinforcing plates <NUM>. The cell array <NUM> includes a number of cells <NUM>. Each of the cells is defined with a length L, a thickness D, and a height H between the length L and the thickness D. The number of cells <NUM> are arranged along a thickness direction, and the cells <NUM> are adhered to each other by a structural adhesive <NUM>. The two first reinforcing plates <NUM> are arranged opposite to each other and are adhered to the two surfaces of the cell array <NUM> along an arrangement direction of the cells <NUM>, and are configured to constrain relative positions between the cells <NUM>.

In the related arts, a number of battery cells <NUM> are first assembled into a battery module. The number of battery modules are assembled into a battery pack <NUM> by fasteners or a structural adhesive. The cells and structural members in the battery pack <NUM> are relatively scattered, and there are many weak points in gaps between fasteners and cells, gaps between cells, and gaps between fasteners. Once the entire battery pack <NUM> is squeezed or impacted by an external force, these weak points will be destroyed by the extemal force, and the fastening effects of the fasteners and adhesive fail, resulting in upcoming damages to the entire battery pack <NUM>.

In order to prevent the damage caused by the external force, in the related arts, the strength of the casing of the battery pack <NUM> is enhanced for resisting external impact by the battery pack <NUM>. In order to enhance the strength of the battery pack <NUM>, a bottom plate <NUM> of a tray <NUM> is made of steel with higher strength or is made thicker. Or the tray <NUM> is configured as a multi-layer structure with cavities, and reinforcing ribs are arranged in the cavity structure. However, all the methods of enhancing the strength of the battery pack <NUM> lead to an increase in the weight of the entire battery pack <NUM> or a reduction in the space utilization of the battery pack <NUM>, reducing the energy density of the battery pack <NUM>.

In the present disclosure, the cells <NUM> are adhered to each other to form a cell array <NUM>, and the two first reinforcing plates <NUM> are adhered to the two opposite surfaces of the cell array <NUM> along the arrangement direction of the cells <NUM>. The two first reinforcing plates <NUM> are configured to constrain the relative positions between the number of cells <NUM>, and form an integral structure with the number of cells <NUM>. Such an integral structure can eliminate the weak points in the gaps between the cells <NUM>, allowing the battery pack <NUM> to be designed as an integral structural member of great rigidity. On the other hand, the two first reinforcing plates <NUM> and the cell array <NUM> arranged between the two first reinforcing plates <NUM> form a honeycomb-like structure. From a mechanical point of view, the honeycomb-like structure can bear the maximum force with the least material. When the cell array <NUM> is subjected to a load perpendicular to the first reinforcing plate <NUM>, the first reinforcing plate <NUM> and the cell array <NUM> deform in coordination. Therefore, the rigidity and strength of the battery pack <NUM> are greatly enhanced, thereby improving the mechanical safety and reliability.

In the present disclosure, as shown in <FIG>, the cell <NUM> is a prismatic cell of a cuboid structure, including two first surfaces opposite to each other in a thickness direction, two second surfaces opposite to each other in a height direction, and two third surfaces opposite to each other in a length direction. The area of the first surface is larger than the area of the second surface, and the area of the first surface is larger than the area of the third surface.

The cells <NUM> are arranged along the thickness direction, and the cells <NUM> are fixedly adhered to each other by a structural adhesive, i.e. the first surfaces of the cells <NUM> are adhered to each other. In other words, the cells <NUM> are arranged and adhered with large surfaces thereof facing toward each other, thereby increasing the area of adhesion between the cells <NUM>, and enhancing the adhesion between the cells <NUM>.

In the arrangement direction of the cells <NUM>, the cells <NUM> are likely to displace relative to each other. Therefore, by the two first reinforcing plates <NUM> are adhered to the two opposite surfaces of the cell array <NUM> along the arrangement direction of the cells <NUM>, the relative positions between the cells <NUM> can be constrained.

In the present disclosure, the two first reinforcing plates <NUM> may be adhered to the two second surfaces of the cells <NUM>, or may be adhered to the two third surfaces of the cells <NUM>.

In the present disclosure, because the length of the cell <NUM> is greater than the height of the cell <NUM> and the height of the cell <NUM> is greater than the thickness of the cell <NUM>, an area of the second surface defined by the length and the thickness is greater than an area of the third surface defined by the height and the thickness. To enhance the adhesion, the two first reinforcing plates <NUM> are adhered to the second surfaces of the cells <NUM>.

In the present disclosure, the two surfaces of all the cells <NUM> along the arrangement direction may be adhered to the first reinforcing plates <NUM>, or, the two surfaces of only some of the cells <NUM> along the arrangement direction may be directly adhered to the first reinforcing plates <NUM>.

That is to say, in the present disclosure, the two second surfaces or the two third surfaces of some of the cells may be adhered to the first reinforcing plates <NUM>, and the two second surfaces or the two third surfaces of some of the cells <NUM> may not be adhered to the first reinforcing plates <NUM>.

In order to improve the adhesion strength, the number of cells <NUM> directly adhered to the two first reinforcing plates <NUM> is not less than half of the number of cells contained in the cell array <NUM>.

For at least one cell <NUM> in the cell array <NUM>, the two second surfaces or the two third surfaces of the cell <NUM> may both be adhered to the two first reinforcing plates <NUM>; or, one of the two second surfaces or the two third surfaces of the cell <NUM> is adhered to the first reinforcing plate <NUM>, and the other is not adhered to the first reinforcing plate <NUM>.

In the present disclosure, the two second surfaces or the two third surfaces of the cell <NUM> are entirely adhered to the first reinforcing plate <NUM>, or the two second surfaces or the two third surfaces of some of the cells <NUM> are partially adhered to the first reinforcing plate <NUM>.

In order to enhance the strength of the entire battery pack <NUM>, in the present disclosure, the two second surfaces or the two third surfaces of all the cells <NUM> in the cell array <NUM> are adhered to the two first reinforcing plates <NUM>, to maximize the strength and rigidity of the battery pack <NUM>.

In the present disclosure, the shapes and areas of the two first reinforcing plates <NUM> are not particularly limited, as long as the two first reinforcing plates <NUM> have a certain strength, can connect the cell array <NUM> to form a unity, can enhance the structural strength of the cell array <NUM>, and are not readily deformable.

In some embodiments, the shape of the first reinforcing plate <NUM> and the shape of the surface of the cell array <NUM> to which the first reinforcing plate <NUM> is adhered are the same and are set corresponding to each other, so that the first reinforcing plate <NUM> can be more easily tightly adhered to the surface of the cell array <NUM>.

In some embodiments, an area of the first reinforcing plate <NUM> may be different from an area of the surface of the cell array <NUM> to which the first reinforcing plate <NUM> is adhered. When the strength of the battery pack <NUM> meets requirements and the first reinforcing plate <NUM> can connect the cell array <NUM> to form a unity, the area of the first reinforcing plate <NUM> may be smaller than the area of the surface of the cell array <NUM> to which the first reinforcing plate <NUM> is adhered.

In some implementations, at least one of the first reinforcing plates <NUM> is a "¬ "-shaped plate, where the "-"-shaped part of the "¬"-shaped plate is arranged in contact with the second surface of the cell <NUM> in the cell array <NUM>, and the "|"-shaped part of the "¬"-shaped plate is arranged in contact with the third surface of the cell <NUM> in the cell array <NUM>; or the "-"-shaped part of the "¬"-shaped plate is arranged in contact with the third surface of the cell <NUM> in the cell array <NUM>, and the "|"-shaped part of the "¬"-shaped plate is arranged in contact with the second surface of the cell <NUM> in the cell array <NUM>.

In some implementations, at least one of the first reinforcing plates <NUM> is a "<IMG> "-shaped plate, where the "-"-shaped part of the " <IMG> "-shaped plate is arranged in contact with the second surface of the cell <NUM> in the cell array <NUM>, and the two "|"-shaped parts of the "<IMG>"-shaped plate are arranged in contact with the third surface of the cell <NUM> in the cell array <NUM>; or the "-"-shaped part of the "<IMG>"-shaped plate is arranged in contact with the third surface of the cell <NUM> in the cell array <NUM>, and the two "|"-shaped parts of the "<IMG>"-shaped plate are arranged in contact with the second surface of the cell <NUM> in the cell array <NUM>.

By arranging a bent portion or bent portions bent toward a side surface of the cell array <NUM> on an edge of the first reinforcing plate <NUM>, the strength and structural stability of the entire cell array <NUM> can be enhanced.

In the present disclosure, the first reinforcing plates <NUM> and the cells <NUM> in the cell array <NUM> constitute a honeycomb-like structure, and the first reinforcing plates <NUM> and the cells <NUM> in the cell array <NUM> deform in coordination. A deformation of the first reinforcing plate <NUM> causes the cell <NUM> to deform at the same time, which is equivalent to providing an additional bending moment to the first surface of the cell <NUM>, resulting in a reduced strength of the honeycomb-like structure. As the thickness of the first reinforcing plate <NUM> increases, the strength of the honeycomb-like structure increases. However, the increase in the strength of the honeycomb-like structure by increasing the thickness of the first reinforcing plate <NUM> cannot exceed a maximum value. This is because the increase in the thickness of the first reinforcing plate <NUM> leads to an increase in the bending rigidity of the first reinforcing plate <NUM>, and when the thickness of the first reinforcing plate <NUM> increases to a certain extent, the strength of the honeycomb-like structure relies on the strength of the cell array <NUM>. Consequently, when an ultimate bearing capacity is reached due to the instability and collapse of the first reinforcing plate <NUM>, the entire honeycomb-like structure loses its bearing capacity. It is found through multiple experiments that when the thickness of the first reinforcing plate <NUM> is <NUM>-<NUM>, the first reinforcing plate <NUM> within this thickness range can provide an optimal reinforcing effect for the honeycomb-like structure, so as to meet the strength requirements of the battery pack <NUM>. In some implementations, the thickness of the first reinforcing plate <NUM> is <NUM>-<NUM>.

In the present disclosure, the first reinforcing plates <NUM> are made of a metal material.

The first reinforcing plates <NUM> made of the metal material not only protect the cells <NUM> inside the battery pack, but also provide a heat dissipation effect. The first reinforcing plates <NUM> may be made of a metal material with high thermal conductivity, including but not limited to aluminum, copper, and alloys thereof.

In practice, the first reinforcing plates <NUM> may be made of an aluminum alloy material, which has a good heat-conducting property and low density.

As shown in <FIG>, <FIG>, and <FIG>, the length direction of the cell <NUM> is defined as a Y direction, the height direction thereof is defined as a Z direction, and the thickness direction is defined as an X direction.

The cell <NUM> is substantially of a cuboid structure. To be specific, the cell <NUM> may be cuboid or cubic, or may be partially special-shaped but basically cuboid or cubic, or may be largely of a cuboid or cubic shape having a notch, a bump, a chamfer, an arc portion, or a bent portion.

In some implementations, the cell <NUM> satisfies: <NUM>≤L≤<NUM>, and <NUM>≤L/D≤<NUM>.

The cell <NUM> has a long length and a small thickness, so the cell <NUM> can be regarded as a rigid member with great strength, which well functions as a reinforcing beam in the casing and reduces the use of reinforcing ribs in the casing, in this way, not only the weight of the battery pack <NUM> can be reduced, but also the structure of the casing can be greatly simplified, thereby improving the utilization of the space inside the battery pack <NUM> and the energy density of the battery pack <NUM>.

According to the invention, in the height direction (i.e., the Z direction) of the cell <NUM>, a number of layers of cell arrays <NUM> are arranged. A partition plate is arranged between two neighboring layers of cell arrays <NUM>, and the partition plate is fixedly adhered to the cell arrays <NUM> on two sides of the partition plate.

In this implementation, with the arrangement of the partition plate between the two layers of cell arrays <NUM>, each layer of cell array <NUM> and the partition plates or panels on upper and lower surfaces of the cell array <NUM> form a number of I-beam structures, to form a honeycomb-like structure. Therefore, the rigidity and strength of the battery pack <NUM> are greatly enhanced, thereby improving the mechanical safety and reliability.

In some implementations, As shown in <FIG>, in order to further enhance the overall strength of the battery pack <NUM>, a second reinforcing plate <NUM> is arranged between at least two neighboring cells <NUM>. The arrangement of the second reinforcing plate <NUM> can well absorb the impact received by the cell array <NUM> in three-dimensional directions, thereby enhancing the mechanical strength of the entire cell array <NUM>.

In the present disclosure, the second reinforcing plate <NUM> may be an aluminum or steel plate. The number of the second reinforcing plates <NUM> is not limited, and may be one or more. When the number of the second reinforcing plates <NUM> is more than one, the second reinforcing plate <NUM> may be arranged between every two neighboring cells <NUM>, or the second reinforcing plate <NUM> may be arranged between only some of the neighboring cells <NUM>.

In order to facilitate the dense arrangement of the cells <NUM> in the entire battery pack <NUM>, in some implementations, the second reinforcing plate <NUM> may be of a shape which is substantially similar to the shape of the cell <NUM>, i.e., may be fabricated into a "dummy cell". The term "dummy cell" means that from the appearance, the dummy cell looks exactly the same as the cell <NUM>, but the dummy cell does not contain an electrode assembly including a positive electrode, a negative electrode, and separator, and provides a reinforcing function only.

The second reinforcing plate <NUM> is fixedly adhered to the cells <NUM> arranged on two sides of the second reinforcing plate <NUM>, to enhance the strength of the entire battery pack <NUM>.

In some implementations, as shown in <FIG>, the battery pack <NUM> further includes an upper cover <NUM> and a tray <NUM>. The tray <NUM> includes a bottom plate <NUM> and a side frame surrounding the bottom plate <NUM>. The upper cover <NUM> and the tray <NUM> are connected to define a cell accommodating chamber, and the cell array <NUM> is arranged in the cell accommodating chamber.

In some implementations, the two first reinforcing plates <NUM> constitute the upper cover <NUM> and the bottom plate <NUM> respectively.

In other words, two surfaces of the cell array <NUM> are respectively adhered to the upper cover <NUM> and the bottom plate <NUM>.

In this implementation, the surface of the cell array <NUM> facing the upper cover <NUM> is adhered to the upper cover <NUM>, and the surface of the cell array <NUM> facing the bottom plate <NUM> is adhered to the bottom plate <NUM>. In this way, the two opposite surfaces of the cell array <NUM> are both adhered to the casing of the battery pack <NUM>, and the cells <NUM> are adhered to each other, which improves the integrity of the battery pack <NUM>, and reduces gaps between fasteners and cells, gaps between cells, and gaps between fasteners. Therefore, weak points in the battery pack <NUM> are reduced, thereby improving the strength and rigidity of the entire battery pack <NUM>.

In some implementations, one of the first reinforcing plates <NUM> is adhered to an inner surface of the upper cover <NUM> (not shown in the figure), and the other first reinforcing plate <NUM> is adhered to an inner surface of the bottom plate <NUM> (as shown in <FIG>). In this way, the cell array <NUM> is indirectly adhered to the casing of the battery pack <NUM>, which facilitates assembly and processing.

In some implementations, the upper cover <NUM> and/or the tray <NUM> may be of a multi-layer composite structure, to enable the battery pack <NUM> to well bear the impact to the entire vehicle, thereby improving the structural strength.

In this implementation, the bottom plate <NUM> of the battery pack <NUM> may be designed as a sandwich composite material structure, which can bear the structural strength of the entire battery module. The bottom plate <NUM> is designed as a composite board structure, and integrates a support strength function and a stone-chip resistant function for the bottom of the battery. The bottom plate <NUM> may also integrate a support strength function and a liquid cooling function for the bottom of the battery.

For example, in some implementations, the multi-layer composite structure includes two layers of aluminum plates and a steel plate or a foamed aluminum plate sandwiched between the two layers of aluminum plates, i.e., the multi-layer composite structure is aluminum plate/foamed aluminum plate/aluminum plate or the multi-layer composite structure is aluminum plate/steel plate/aluminum plate.

In some other implementations, the multi-layer composite structure includes two fiber composite layers and a foamed material layer sandwiched between the two fiber composite layers.

The foamed material layer includes a foamed polymer material, e.g., a polyurethane foam or phenolic foam material. The foamed material layer has a low thermal conductivity and can provide a good thermal insulation effect. In addition, the foamed material is of low density, and can reduce the weight of the battery pack <NUM> as compared with the case where the sealing cover is made of a steel plate or aluminum alloy.

The fiber composite layer includes a glass fiber layer and/or a carbon fiber layer. In other words, the multi-layer composite layer may be glass fiber layer/foamed material layer/glass fiber layer, carbon fiber layer/foamed material layer/carbon fiber layer, or glass fiber layer/foamed material layer/carbon fiber layer. By designing the upper cover <NUM> and/or the tray <NUM> of the battery pack <NUM> as a foamed material layer and fiber composite layers distributed on inner and outer sides of the foamed material layer, the fiber layers are of a high tensile strength and elastic modulus, are deformation-resistant when the internal pressure of the battery pack <NUM> increases within a certain range, and can also effectively insulate fire and heat, thereby improving the safety performance of the battery pack <NUM> under extreme conditions.

The structural strength of the integral battery pack <NUM> may provide part of the structural strength of the vehicle. The battery pack <NUM> can be used to enhance the structural strength of the vehicle, such a design allows for the simplification of the structure designed for the frame of the vehicle to protect the structural strength of the battery pack <NUM>, and meets the requirements for a lightweight design of the vehicle, thereby reducing the manufacturing costs and improving the efficiency of vehicle production.

In some implementations of the present disclosure, as shown in <FIG>, for example, in the implementation where the two first reinforcing plates <NUM> constitute the upper cover <NUM> and the bottom plate <NUM> respectively, the bottom plate <NUM> of the tray <NUM> is a single-layer aluminum plate, a protection plate <NUM> is arranged on an outer surface of the bottom plate <NUM> of the tray <NUM>, and the protection plate <NUM> is a multi-layer composite structure. The protection plate <NUM> can effectively protect the bottom of the power battery pack <NUM> to prevent the power battery pack <NUM> from being directly damaged by stone chips or bumping, meets the ball impact requirements on the bottom by a lightweight design, and has good safety and reliability. In addition, the composite material of the protection plate <NUM> at the bottom has environmental reliability such as corrosion resistance and aging resistance. The design of the bottom plate <NUM> as a detachable compact structure with strong protection facilitates after-sales maintenance in the future, and greatly reduces after-sale maintenance costs.

For the multi-layer composite structure of the protection plate <NUM>, reference may be made to the above descriptions, so the details will not be repeated herein.

Various connection and fixing methods may be designed for the protection plate <NUM> and the side frame of the tray <NUM> of the battery pack <NUM>, including riveting, automatic punch riveting, bolted connection, etc., which can be disassembled freely and facilitates repair, maintenance and inspection.

As shown in <FIG>, the upper cover <NUM> is provided with a sealing groove at a position corresponding to the side frame, a sealant layer is arranged in the sealing groove, and the upper cover <NUM> and the tray <NUM> are hermetically connected by the sealant.

In some implementation, the sealing groove may be provided on only the upper cover <NUM> or on only the side frame, or the upper cover <NUM> and the side frame are each provided with the sealing groove.

In some implementation, the upper cover <NUM> may also be hermetically fixed to the side frame by riveting or bolts, so as to improve the sealing performance and the structural strength of the entire battery pack <NUM>.

At the position for sealed fitting between the side frame of the battery and the upper cover <NUM>, a sealing groove is designed for sealing. The sealing groove may be designed on the side frame of the battery or on the upper cover <NUM>, to ensure the sealing and fixing between the side frame and the upper cover <NUM>.

A structural adhesive is filled between the cell array <NUM> and an inner surface of the side frame. A gap between the cell array <NUM> and the side frame often becomes a weak point, and by injecting the structural adhesive to adhere the cell <NUM> to the side frame, the strength is enhanced.

As shown in <FIG>, in some embodiments, each of the cells <NUM> is substantially of a cuboid structure, including a first end and a second end arranged opposite to each other along the length direction. The side frame includes a first side frame <NUM> and a second side frame <NUM> arranged opposite to each other along the length direction of each of the cells <NUM>. The cells <NUM> are disposed between the first side frame <NUM> and the second side frame <NUM>. The first end of each of the cells <NUM> is supported by the first side frame <NUM>, and the second end of each of the cells <NUM> is supported by the second side frame <NUM>. In other words, the cells <NUM> extend between the first side frame <NUM> and the second side frame <NUM>.

Because the cells <NUM> extend between the first side frame <NUM> and the second side frame <NUM>, and the two ends of the cell <NUM> are respectively supported by the first side frame <NUM> and the second side frame <NUM>, the cell <NUM> itself can serve as a transverse beam or longitudinal beam to enhance the structural strength of the casing. That is to say, no reinforcing structure for enhancing the structural strength needs to be arranged in the casing, that is, the cell <NUM> itself can be directly used to replace the reinforcing structure to ensure the structural strength of the casing, thereby ensuring that the casing does not easily deform under an external force.

In some embodiments of the present disclosure, a first support step <NUM> is arranged on the first side frame <NUM>, a second support step is arranged on the second side frame <NUM>, the first end of each of the cells <NUM> is supported by the first support step <NUM>, and the second end of each of the cells <NUM> is supported by the second support step.

In some embodiments of the present disclosure, the first end of each of the cells <NUM> may be directly or indirectly supported by the first side frame <NUM>, and the second end of each of the cells <NUM> may be directly or indirectly supported by the second side frame <NUM>. The term "directly" means that the first end of the cell <NUM> is in direct contact fit with and supported by the first side frame <NUM>, and the second end of each of the cells <NUM> is in direct contact fit with and supported by the second side frame <NUM>.

As shown in <FIG>, the battery pack <NUM> further includes a supporting structure. The first end of each of the cells <NUM> is fitted to and supported by the first side frame <NUM> through the supporting structure, and the second end of the cell <NUM> is fitted to and supported by the second side frame <NUM> through the supporting structure.

In this implementation, the term "fit" means that a spacing between the two side frames is configured for mounting one cell <NUM>. The fit may be various fitting methods such as clearance fit, interference fit, tight fit, immovable fit, etc., thereby achieving the objective of the present disclosure.

The arrangement of the supporting structure between the two ends of the cell <NUM> in the length direction and the side frame can enhance the strength of the cell array <NUM> and the strength of the battery frame.

With the arrangement of the supporting structure, when the side frame receives an external force, the cell <NUM> itself is a rigid member with great strength, and can transmit a force to the side frame through the supporting structure, to prevent plastic deformation of the side frame.

In some implementations, as shown in <FIG>, and <FIG>, the supporting structure includes a first support block <NUM>, a lower surface of the first end of each of the cells <NUM> is supported by the first side frame <NUM> through the first support block <NUM>, and/ or a lower surface of the second end of the cell <NUM> is supported by the second side frame <NUM> through the first support block <NUM>.

The first support block <NUM> is fixedly mounted on lower surfaces of the ends of the cell <NUM> in the length direction, which on the one hand facilitates the positioning of the cells <NUM> when the cells are arranged to form the cell array <NUM>, and on the other hand insulates and isolates the cells <NUM> from the bottom plate <NUM> of the tray <NUM>. In addition, the side frame can be connected to a lower end surface of the cell <NUM> by the first support block <NUM>, thereby improving the strength and rigidity of the entire battery pack <NUM>.

Through the first support block <NUM>, the lower surface of the first end of each of the cells <NUM> may be supported by the first side frame <NUM>, or may be supported by the support step on the first side frame <NUM>. Through the first support block <NUM>, the lower surface of the second end of the cell <NUM> may be supported by the second side frame <NUM> through the first support block <NUM>, or may be supported by the support step on the second side frame <NUM>.

In some implementations of the present disclosure, the supporting structure includes a second support block <NUM>, the first end of each of the cells <NUM> facing the first side frame <NUM> is fitted to the first side frame <NUM> through the second support block <NUM>, and/or, the second end of each of the cells <NUM> facing the second side frame <NUM> is fitted to the second side frame <NUM> through the second support block <NUM>.

Each of the cells <NUM> includes electrode terminals. The electrode terminals are respectively arranged at the first end and the second end of each of the cells <NUM>. Holes <NUM> are provided on the supporting structure. The electrode terminals of each of the cells <NUM> extend through the holes <NUM> respectively and are electrically connected by a cell connector <NUM>.

In a first implementation of the present disclosure, as shown in <FIG> and <FIG>, the battery pack <NUM> further includes an insulation partition plate <NUM>, and the insulation partition plate <NUM> is arranged between the supporting structure and an inner surface of the side frame. The insulating partition plate is configured to insulate the cell connector <NUM> and the electrode terminals from the side frame, to prevent a short circuit and other safety problems.

As shown in <FIG> and <FIG>, a second supporting structure is mounted on a side surface of the electrode terminals, to fix the cell connector <NUM> of each of the cells <NUM> and a flexible printed circuit board (FPC).

The electrode terminals of each of the cells <NUM> are also weak points, and the second support block <NUM> can protect the electrode terminals.

In the present disclosure, the specific structure of the supporting structure is not limited, as long as the supporting structure is of a certain strength and is resistant to deformation under an external force. In some implementations, the material of the supporting structure includes one or more of polyether plastic (PPS), glass fiber, or polycarbonate.

In some embodiments of the present disclosure, the side frame includes a third side frame <NUM> and a fourth side frame arranged opposite to each other along the arrangement direction of the cells <NUM>. The number of cells <NUM> are arranged side by side between the third side frame <NUM> and the fourth side frame. The third side frame <NUM> and the fourth side frame are respectively fixedly adhered to each of the cells <NUM> adjacent thereto.

The arrangement of the third side frame <NUM> and the fourth side frame makes the cell array <NUM> and the side frame to form a unity, and the side frame of the battery tightly clamps the cell array <NUM> along the arrangement direction of the cells <NUM>.

That is to say, the third side frame <NUM> applies an acting force, which is toward the fourth side frame, on the cell <NUM> arranged adjacent to the third side frame <NUM>, and the fourth side frame applies an acting force, which is toward the third side frame <NUM>, on the cell <NUM> arranged adjacent to the fourth side frame, so that the number of cells <NUM> can be closely arranged between the third side frame <NUM> and the fourth side frame, and the number of cells <NUM> can closely fit each other. Moreover, the third side frame <NUM> and the fourth side frame may provide a limiting function for the cells <NUM>, and especially when the cell <NUM> undergoes slight expansion, may provide a buffering function and an inward pressure for the cell <NUM>, to prevent the cell <NUM> from excessive expansion and deformation.

In order to further solve the expansion problem of the cell array <NUM>, a reinforcing beam is arranged on the third side frame <NUM> and/or the fourth side frame. The reinforcing beam may be in close contact with to the outer surface of each of the cells adjacent thereto or may be spaced from each of the cells adjacent thereto by a gap, to provide a limiting function for the expansion of the cell array <NUM>.

The side frame and the bottom plate <NUM> of the tray <NUM> may be adhered to each other by a structural adhesive, may be directly welded together, or may be connected by bolts. The side frame may be an integral frame or a split-type frame. In some embodiments of the present disclosure, the side frame is a split-type frame, i.e. the first side frame <NUM>, the second side frame <NUM>, the third side frame <NUM>, and the fourth side frame are separate from each other. The connection between the two side frames may be further reinforced by a fastener.

An assembly process of the battery pack <NUM> is described below using an example where each of the cells <NUM> is a cuboid cell, the electrode terminals of each of the cells <NUM> are arranged on the two ends of the cell <NUM> along the length direction, the first side frame <NUM>, the second side frame <NUM>, the third side frame <NUM>, and the fourth side frame are separate from each other, and the two first reinforcing plates <NUM> constitute the upper cover <NUM> and the bottom plate <NUM> of the battery pack respectively.

Step <NUM>: The number of cells <NUM> are arranged along the thickness direction to form the cell array, with the cells <NUM> being aligned to each other in the height direction and the length direction. The cells <NUM> are adhered to each other by a structural adhesive <NUM>. The arrangement direction of the cells <NUM> is defined as an X direction. The length direction of the cell <NUM> is defined as a Y direction.

Step <NUM>: Along the X direction, two opposite first surfaces with the largest areas of the two outermost cells <NUM> in the cell array <NUM> are respectively adhered to the third side frame <NUM> and the fourth side frame (where this direction is not a lead-out direction of the electrode terminals).

Step <NUM>: Along the Y direction, the first side frame <NUM> and the second side frame <NUM> are arranged on the two end faces of the cell array <NUM>.

Step <NUM>: The first side frame <NUM> and the second side frame <NUM> are connected to the third side frame <NUM> and the fourth side frame by welding or fasteners (bolts, etc.).

Step <NUM>: The two first reinforcing plates <NUM> are adhered to the two opposite surfaces of the cell array <NUM> along the arrangement direction of the cells <NUM>.

Step <NUM>: The first reinforcing plates <NUM> are connected to the first side frame <NUM>, the second side frame <NUM>, the third side frame <NUM>, and the fourth side frame by a structural adhesive or fasteners. One of the first reinforcing plates <NUM> is the upper cover <NUM> of the battery pack <NUM>. The other first reinforcing plate <NUM> is the bottom plate <NUM> of the battery pack <NUM>.

Step <NUM>: The protection plate <NUM> is further arranged on the outer surface of the bottom plate <NUM>.

Step <NUM>: A structural adhesive is filled in or a supporting structure is arranged at the gap between the cell array <NUM> and the side frame.

As can be seen from the above assembly process, the six surfaces of the cell <NUM> are all of a strong structural strength, and the design of the battery pack <NUM> as an integral structure greatly enhances the rigidity and strength, thereby greatly improving the mechanical safety and reliability. The structural strength of the integral battery pack <NUM> may provide part of the structural strength of the vehicle. The battery pack <NUM> can be used to enhance the structural strength of the vehicle, such a design allows for the simplification of the structure designed for the frame of the vehicle to protect the structural strength of the battery pack <NUM>, and meets the requirements for a lightweight design of the vehicle, thereby reducing the manufacturing costs and improving the efficiency of vehicle production.

In the present disclosure, the battery pack <NUM> further includes a battery management system.

According to a second aspect of the present disclosure, an electric vehicle is provided, including the above battery pack <NUM>. The electric vehicle has a long battery life and requires low costs.

In the description of the present disclosure, it should be noted that unless otherwise explicitly specified or defined, the terms such as "mount", "install", "connect", and "connection" should be understood in a broad sense. For example, the connection may be a fixed connection, a detachable connection, or an integral connection; or the connection may be a mechanical connection or an electrical connection; or the connection may be a direct connection, an indirect connection through an intermediary, or internal communication between two components. A person of ordinary skill in the art may understand the specific meanings of the foregoing terms in the present disclosure according to specific situations.

In description of this specification, description of reference terms such as "an embodiment", "specific embodiments", or "an example", means including specific features, structures, materials, or features described in the embodiment or example in at least one embodiment or example of the present disclosure. In this specification, schematic descriptions of the foregoing terms do not necessarily point at a same embodiment or example. In addition, the described specific features, structures, materials, or characteristics may be combined in a proper manner in any one or more of the embodiments or examples.

Claim 1:
A battery pack (<NUM>), comprising:
a cell array (<NUM>), wherein the cell array comprises a plurality of cells (<NUM>); each of the cells is defined with a length L, a thickness D, and a height H between the length L and the thickness D,
the plurality of cells (<NUM>) are arranged along a thickness direction, and the cells are adhered to each other by a structural adhesive (<NUM>);
two first reinforcing plates (<NUM>); wherein the two first reinforcing plates are arranged opposite to each other and are respectively adhered to two surfaces of the cell array (<NUM>) along an arrangement direction of the cells (<NUM>), and are configured to constrain relative positions between the cells;
characterized in that the battery pack comprises a plurality of layers of cell arrays (<NUM>) arranged along a height direction (Z) of the cells, a partition plate is arranged between two neighboring layers of cell arrays, and the partition plate is fixedly adhered to the cell arrays on two sides of the partition plate.