End plate of battery module and battery module

The present application relates to the technical field of batteries and, particularly, relates to an end plate of a battery module and a battery module. The end plate of a battery module includes a main body and an energy absorbing body, the energy absorbing body includes an acting portion and a connecting portion, the acting portion protrudes in a direction from the main body toward a battery, and the acting portion is connected with the main body through the connecting portion. After the battery module is assembled, if the battery of the battery module expands and applies an expansion force to the end plate, then the energy absorbing body will deform elastically, so as to absorb the expansion force of the battery. Therefore, the end plate can prevent the housing of the battery module from failure, so as to improve structural strength of the battery module.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of priority to Chinese Patent Application No. 201621443282.3, filed on Dec. 27, 2016, the content of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present application relates to the technical field of batteries and, particularly, relates to an end plate of a battery module and a battery module.

BACKGROUND

The housing is one of the core components of a battery module, the interior of the housing forms space for accommodating the battery. A traditional housing of a battery module mainly includes a pair of side plates, a pair of end plates, a bottom plate and a top plate. The end plates are fixed with the side plates through welding, screw threads etc. As continuous increasing of capacity of the battery module, the expansion force applied to the housing by the battery in the housing is also continuously increasing, which may easily cause deformation and displacement of the end plate, leading to connection failure between the side plates and the end plates (such as welding seam failure between the side plates and the end plates, bolt connection failure between the side plates and the end plates caused by an overlarge shearing force). Therefore, traditional battery modules have the problem of low structural strength.

SUMMARY

The present application provides an end plate of a battery module and a battery module, so as to improve structural strength of the battery module.

A first aspect of the present application provides an end plate of a battery module, including a main body and an energy absorbing body, the energy absorbing body includes an acting portion and a connecting portion, the acting portion protrudes in a direction from the main body toward a battery, and the acting portion is connected with the main body through the connecting portion.

Preferably, the main body has a connecting hole, the energy absorbing body is arranged at the connecting hole, and a surface of the energy absorbing body facing toward the connecting hole is a concave surface.

Preferably, a through hole is defined in the connecting portion, the through hole is communicated with the connecting hole.

Preferably, an auxiliary deforming hole is defined in the acting portion, and the auxiliary deforming hole penetrates through the acting portion.

Preferably, the connecting portion is structured in a strip shape, one end of the connecting portion is fixedly connected with the main body, and the other end of the connecting portion is fixed at an edge of the acting portion.

Preferably, the connecting portion is obliquely arranged relative to a protruding direction of the acting portion, and the end of the connecting portion connected with the acting portion is closer to the acting portion than the other end of the connecting portion.

Preferably, a plurality of energy absorbing bodies is arranged, and the plurality of energy absorbing bodies is arranged on the main body and is spaced from each other.

Preferably, a surface of the acting portion of each energy absorbing body away from the main body is a flat surface, and the flat surfaces of all the acting portions are parallel and level to each other.

A second aspect of the present application provides a battery module, including a rigid end plate and a plastic end plate, the plastic end plate is arranged between a battery in the battery module and the rigid end plate, and the rigid end plate is any one of the end plate of a battery module as mentioned above.

Preferably, the plastic end plate includes a plastic main body and a cooperative protruding portion fixed with the plastic main body, the cooperative protruding portion protrudes from the plastic main body toward a side close to the rigid end plate, and the cooperative protruding portion abuts with the acting portion.

The technical solution provided by the present application can reach the following beneficial effects:

The end plate of a battery module provided by the present application includes a main body and an energy absorbing body, after the battery module is assembled, if the battery of the battery module expands and applies an expansion force to the end plate of a battery module, then the energy absorbing body will deform elastically, so as to absorb the expansion force of the battery. Therefore, the end plate of a battery module can prevent the housing of the battery module from failure, so as to improve structural strength of the battery module.

It should be understood that, the above general description and the following detailed description are just exemplary, which cannot limit the present application.

REFERENCE SIGNS

10—end plate of battery module;

The drawings are incorporated into the present description and form a part thereof, which show embodiments of the present application, and are used to explain the principle of the present application together with the description.

DESCRIPTION OF EMBODIMENTS

The present application will be described in further detail with reference to the following embodiments and the accompany drawings.

As shown fromFIG. 1toFIG. 6, embodiments of the present application provide an end plate10of a battery module, the end plate10forms a housing of the battery module together with side plates11, a bottom plate and a top plate. A battery12of the battery module can be placed in the housing.

The above-mentioned end plate10can include a main body101and an energy absorbing body102. The main body101is the main structure of the end plate10, and the main body101can be welded with the side plate11. The energy absorbing body102can be arranged on the main body101, specifically, the energy absorbing body102can be welded on the main body101, or the energy absorbing body10and the main body101are integrated as a whole, or they are connected with each other adopting other manners.

The energy absorbing body102can include an acting portion102aand a connecting portion102b. The acting portion102aprotrudes from the main body101toward a side where the battery12is located. At this time, a surface of the acting portion102afacing toward the battery12forms a first-stage stress surface, and a surface of the main body101facing toward the battery12forms a second-stage stress surface. The acting portion102ais connected with the main body101through the connecting portion102b, so that the entire energy absorbing body102has certain elastic deformation amount relative to the main body101. That is, after bearing an external force, the energy absorbing body102can absorb the external force through self-deformation, so as to avoid problems such as deformation and displacement of the end plate10as well as fracture of a fastening piece in the battery module caused by shearing force.

After the battery module is assembled, if the battery12of the battery module expands, and applies an expansion force to the end plate10, then the energy absorbing body102will deform elastically, so as to absorb the expansion force of the battery12. Therefore, the end plate10can prevent the housing of the battery module from failure, so as to improve structural strength of the battery module. Moreover, the end plate10can release the expansion force of the battery12, so as to prolong the service life of the battery module.

Besides, the above-mentioned first-stage stress surface and second-stage stress surface can be formed on the above-mentioned end plate10, the expansion force of the battery12is firstly absorbed by the first-stage stress surface, so as to reduce the expansion force, the remaining expansion force is then transferred to the second-stage stress surface, so that the deformation amount of the end plate10is smaller, or even no deformation will occur.

In order to further improve the elastic deformation ability of the energy absorbing body102, a connecting hole can be defined in the main body101, and the energy absorbing body102is arranged at the connecting hole. Specifically, the connecting portion102bcan be fixed at an edge of the connecting hole. After such arrangement, the rigidity of a position of the main body101where the energy absorbing body102is arranged will be reduced due to the connecting hole. As a result, after the energy absorbing body102has absorbed the expansion force, the deformation magnitude of the energy absorbing body102will be larger, so as to achieve the above-mentioned purpose. Further, a surface of the energy absorbing body102facing toward the connecting hole can be provided to be a concave surface, a concave direction of the concave surface is a direction close to the battery. After providing the concave surface, the thickness of the energy absorbing body102is smaller, so that the energy absorbing body102is more easily deformed, thereby absorbing more expansion force.

Further, a through hole can be defined in the connecting portion102b, the through hole is communicated with the connecting hole. Adopting such a structure can allow larger elastic deformation amount of the connecting portion102b, so as to better optimize performance of the energy absorbing body102.

After the battery module is assembled, the above-mentioned acting portion102acan directly contact with the battery12, so as to bear the expansion force of the battery12. An auxiliary deforming hole102aacan be further defined in the acting portion102a. The auxiliary deforming hole102aapenetrates through the acting portion102a, so that the acting portion102ahas a larger elastic deformation after being stressed. Specifically, the auxiliary deforming hole102aacan be a round-hole, square-hole, oval-hole and the like, which can be located at the central portion of the acting portion102a.

In embodiments of the present application, the deformation ability of the energy absorbing body102is related to the structure of the connecting portion102b. Generally, if other factors are not taken into consideration, the higher the rigidity of the connecting portion102bis, the worse the deformation ability of the energy absorbing body102is; on the contrary, the lower the rigidity of the connecting portion102bis, the higher the deformation ability of the energy absorbing body102is. Accordingly, the connecting portion102bcan be structured as a strip shape, one end of the connecting portion102bis fixedly connected with the main body101, the other end is fixed at an edge of the acting portion102a. Comparing to other structures, the connecting portion102badopting the strip-shaped structure can properly reduce the rigidity thereof, so as to achieve the effect of improving the deformation ability of the energy absorbing body102.

Furthermore, the connecting portion102bis obliquely arranged relative to the protruding direction of the acting portion102a, and the end of the connecting portion102bconnected with the acting portion102ais closer to the acting portion102athan the other end. That is, the entire energy absorbing body102presents a gradual contraction structure along a direction close to the battery12. When adopting such a structure, in order to guarantee the structural strength of the energy absorbing body102, a plurality of connecting portions102bcan be arranged in interval along the edge of the acting portion102a. Further, connecting portions102bare uniformly arranged along the edge of the acting portion102a. When the connecting portion102badopts a straight strip-shaped structure, the connecting portion102bforms an inclining angle α relative to the protruding direction of the acting portion102a.

As shown inFIG. 5, after adopting the above-mentioned structure, the expansion force F stressed by the energy absorbing body102can be decomposed into two component forces, respectively F1and F2. The F2of opposite directions can counteract each other, so as to further reduce the expansion force stressed by the entire end plate10. Since the inclining angle α of the connecting portion102bdetermines the magnitude of the component forces F1and F2, therefore, the value of the inclining angle α can be designed according to the expansion force transferred onto the end plate10and the rigidity parameter of the end plate10, etc. The larger the expansion force is, the larger the rigidity is required, then the inclining angle α can adopt a larger value, so that the component force F2is larger; otherwise, a smaller value shall be adopted. Considering various requirements, in embodiments of the present application, the inclining angle α can be set as 30°-45°.

One or more energy absorbing body102can be provided. In order to improve the energy absorbing effect of the energy absorbing body102, a plurality of energy absorbing bodies102can be provided, the energy absorbing bodies102are arranged on the main body101in interval. Further, in each energy absorbing body102, a surface of the acting portion102away from the main body101can be provided to be a flat surface, so as to simplify processing of the end plate10and, at the same time, appropriately increase a stress area of the acting portion102awhen bearing the expansion force. Furthermore, the above-mentioned flat surfaces of the acting portions102bare parallel and level to each other, so as to strengthen the ability of the end plate10on bearing the expansion force.

It shall be understood that, factors such as the number of the above-mentioned connecting portion102b, the size of the above-mentioned connecting portion102b, the number of the above-mentioned energy absorbing body102and the interval between each two adjacent energy absorbing bodies102and the like will influence the ability of the end plate10on absorbing the expansion force. Therefore, when designing the structure of the end plate10, the structure of the end plate10can be appropriately arranged by taking parameters such as application scenario of the battery module, structure of the battery module and the like into consideration.

Based on the above-mentioned structure, as shown inFIG. 1andFIG. 6, embodiments of the present application also provide a battery module. The battery module can include a rigid end plate and a plastic end plate13. The plastic end plate13can be placed between the battery12and the rigid end plate, the material of the rigid end plate can be steel. Specifically, the rigid end plate can be the end plate10described in any one of the above embodiments. The plastic end plate13can firstly bear a part of expansion force, the remaining expansion force will be transferred onto the rigid end plate, and absorbed by the energy absorbing body102of the rigid end plate.

In the above-mentioned battery module, the plastic end plate13cooperates with the rigid end plate, when the rigid end plate adopts the above-mentioned end plate10provided by the embodiments of the present application, the plastic end plate13can include a plastic main body130and a cooperative protruding portion131fixed with the plastic main body130. The cooperative protruding portion131protrudes relative to the plastic main body toward a side close to the rigid end plate, and the cooperative protruding portion131abuts with the acting portion102aof the rigid end plate.

Preferably, the abutting surface between the above-mentioned cooperative protruding portion131and the acting portion102ais a first flat surface, that is, both the cooperative protruding portion131and the acting portion102ahave the first flat surface, the first flat surfaces are fitted with each other. A surface of the main body101of the rigid end plate facing toward the plastic end plate13is a second flat surface, the first flat surface and the second flat surface are parallel to each other. Such an arrangement can allow the end plate10more effectively bearing the expansion force, and prevent the battery module from moving relative to the plastic end plate13after bearing the expansion force. Therefore, such an arrangement can further improve the reliability of the housing. Alternatively, both the above-mentioned two first surfaces can adopt a round surface.

In an embodiment, in a direction of the plastic end plate13opposite to the rigid end plate, a preset gap is defined between the portion of the plastic end plate13, except the cooperative protruding portion131, and the rigid end plate. Such a solution, in one aspect, can provide space for the deformation of the energy absorbing body102of the rigid end plate and, in the other aspect, can prevent the expansion force stressed by the plastic end plate13from being directly transferred to the rigid end plate.

The above are just the preferred embodiments of the present application, which will not limit the present application. For those skilled in the art, the present application can have various modifications and variations. Any modifications, equivalent replacements and improvements made within the spirits and principles of the present application shall all fall into the protection scope of the present application.