Space efficient modular lithium ion battery pack structure

Abstract

The invention discloses a space efficient modular lithium ion battery pack structure. The space efficient modular lithium ion battery pack structure is mainly characterized in that a minimum'subset 'unit in a lithium ion battery pack capable of adapting to different energy requirements is designed to solve the basic module problem of a space large-scale lithium ion battery pack; through the design of four strings of standard battery modules and six strings of standard battery modules, the problem of assembling battery groups with different voltage levels can be completely solved; by adopting the highly integrated and standardized battery module design, the standardization degree of each component in the battery pack can be greatly improved, and the problems of rapid production and rapid application of the battery pack are solved.

Description

Technical Field

[0001] The present invention relates to a key technology for the efficient modular application of lithium-ion battery packs in the field of space aerospace, belonging to the field of aerospace energy technology, and is particularly applicable to application scenarios such as rapid response, modular and efficient integration represented by commercial satellites. Background Art

[0002] At present, the energy storage power supply of my country's satellite platform is mostly based on lithium-ion battery packs as the main energy storage unit, which is an important part of the whole satellite design. Usually, lithium-ion battery packs need to be customized according to the technical requirements of the satellite's space envelope, installation location, weight distribution, voltage level, output energy requirements, power requirements, and cycle life. Therefore, the battery pack has problems such as low standardization and is difficult to adapt to the application of large-scale commercial satellites in the future.

[0003] Space lithium-ion battery packs are composed of single cells connected in series and parallel, structural parts and thermal control components. At present, the bus voltages of domestic power subsystems mainly include 28V, 42V, 100V and other types of power supply buses. At the same time, according to different application requirements, the voltage is divided into a regulating bus and a non-regulating bus. Therefore, the current design of battery packs includes 7, 8, 9, 11, 16, 20, 22 and 24 battery series. At the same time, due to the different capacities of energy storage battery packs, the capacity of battery packs also varies greatly, ranging from 30Ah to 200Ah. It is necessary to design batteries of different capacities to form battery packs through a large number of series and parallel connections to meet energy requirements. Summary of the invention

[0004] The technical problem solved by this application is: to overcome the shortcomings of the existing technology and provide a space efficient modular lithium-ion battery pack structure, which can meet the future space energy storage power supply application needs represented by commercial satellites through the rapid grouping of basic modules; and solve the difficult problems such as "the current space aerospace lithium-ion battery pack has a low degree of standardization, such as a wide variety of battery pack modules, and extremely complex designs in appearance, size, space envelope, battery pack interface, etc."

[0005] This application mainly targets the modular design requirements of space lithium-ion battery packs, finds the smallest subset unit in the battery pack, and designs standardized battery pack modules. Based on this standardized module, the architecture is quickly iterated and grouped to meet the needs of future commercial satellites for efficient and highly integrated energy storage battery packs.

[0006] The main improvement method of the present invention comes from the analysis of existing traditional customized space lithium-ion battery packs, designing the smallest "subset" unit in lithium-ion battery packs of different sizes, and using this smallest unit for flexible expansion design to solve the application problems of current standardized and modular energy storage battery packs.

[0007] The technical solutions provided by this application are as follows:

[0008] A space-efficient modular lithium-ion battery pack structure includes at least one battery pack unit, and different battery pack units are connected in parallel or in series; each battery pack unit includes a bottom plate, an end plate, a tie rod and a plurality of single cells, the end plate is connected to opposite ends of the bottom plate, a plurality of single cells are installed between the two end plates, the tie rod is connected between the two end plates, and the tie rod contacts one end of the single cell away from the bottom plate, so as to fix the single cell between the two end plates and the bottom plate.

[0009] The bottom plate is provided with a plurality of limiting grooves, and each single cell has a convex block at the bottom, and the convex blocks are matched with the limiting grooves one by one, so that the bottoms of the plurality of single cells are clamped with the bottom plate.

[0010] It also includes a plurality of guide bars, which are connected to the positive electrode terminals and the negative electrode terminals of two adjacent single cells so as to connect the two adjacent single cells in series.

[0011] A total positive bus and a total negative bus are respectively arranged on opposite sides of the two end plates. The positive electrode terminals of the single cells at the end are connected to the total positive bus through a guide bar, and the negative electrode terminals of the single cells at the other end are connected to the total negative bus through a guide bar.

[0012] The end plate is provided with a lead-out port, so that the total positive bus and the total negative bus extend to the opposite side of the end plate through the lead-out port, so that the battery pack units can be connected in series or in parallel through the total positive bus and the total negative bus.

[0013] A first ear piece is fixedly connected to one end plate connected to the bottom plate on one side away from the single cell, and a second ear piece is fixedly connected to the other end plate connected to the bottom plate on one side away from the single cell. Bolts pass through the first ear piece and the second ear piece to connect and fix the first ear piece and the second ear piece.

[0014] The distances between the bottom surfaces of the first ear piece and the second ear piece and the bottom surface of the bottom plate are different, wherein the high ear piece has a larger distance from the bottom surface of the bottom plate, and the low ear piece has a smaller distance from the bottom surface of the bottom plate; the bottom surface of the low ear piece is flush with the bottom surface of the bottom plate, and the distance between the bottom surface of the high ear piece and the bottom surface of the bottom plate is the thickness of the low ear piece.

[0015] The battery pack unit also includes a model battery, which has the same appearance and structure as the single battery but does not have the function of providing electricity; the model battery and the single battery are both located between the two end plates.

[0016] In summary, this application at least includes the following beneficial technical effects:

[0017] By designing lithium-ion battery modules with standard modular design, finding the smallest subset unit in large-scale battery packs, and quickly assembling them into groups in a "building blocks" manner, we can solve the current problems of complex series and parallel connection and customized design of satellite battery packs, greatly improve the standardization and integration of space lithium-ion battery packs, and meet the high-density application needs of commercial satellites. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Design lithium-ion battery modules for 4S standard modularization;

[0019] Figure 2 Design lithium-ion battery modules for 6S standard modularization;

[0020] Figure 3 Designed for N-parallel 7-series lithium-ion battery pack;

[0021] Figure 4 Standardized design diagrams for different platform voltage series;

[0022] Figure 5 Design diagram for two sets of standard modules connected in series.

[0023] Description of the accompanying drawings: 1-single cell, 2-guide bar, 3-end plate, 4-pull rod, 51-first ear piece. DETAILED DESCRIPTION

[0024] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments disclosed in the present invention will be further described in detail below with reference to the accompanying drawings.

[0025] The present application embodiment discloses a space efficient modular lithium ion battery pack structure, such as Figure 1 As shown, at least one battery pack unit is included.

[0026] The battery pack unit is a basic module. The battery pack unit is a standard module designed for 4 strings and 6 strings. First, the structure of the 4-string and 6-string standard modules is designed, such as Figure 1 and Figure 2 As shown, a two-end tie rod structure is adopted, and the tie rod is designed inside the envelope space of the battery pack body to prevent the tie rod from interfering with the external space when modularly assembled into groups. The front and rear end plates tightly constrain the battery inside the battery pack, and the monomers are connected in series through multiple layers of guide copper strips. On the end plates on both sides of the battery pack, mounting screw holes for horizontal and vertical grouping are designed. Lightweight flexible materials are designed inside the battery pack to suppress the longitudinal volume expansion of the battery. Mounting holes are designed on the bottom surface of the battery to achieve reliable connection between the battery module and the cabin. The battery structural parts are made of lightweight and low-density magnesium alloy materials, and local reinforcement ribs are designed to improve the strength of the external structure to ensure that it can adapt to high mechanical magnitudes such as satellite vibration.

[0027] Specifically, the battery pack unit includes a bottom plate, an end plate 3, a tie rod 4, a plurality of guide bars 2 and a plurality of single cells 1. The end plate 3 is connected to the two opposite ends of the bottom plate; the bottom plate is provided with a plurality of limit grooves, each single cell 1 has a protrusion at the bottom, and the protrusions match the limit grooves one by one, so that the bottoms of the plurality of single cells 1 are clamped with the bottom plate, and the plurality of single cells 1 are installed between the two end plates 3. Two tie rods 4 are provided, and the two tie rods 4 are connected between the two end plates, and the tie rods 4 are in contact with one end of the single cell 1 away from the bottom plate.

[0028] The two end plates 2 are provided with a total positive bus and a total negative bus respectively on opposite sides. The end of the single cell 1 away from the bottom plate is provided with a positive terminal and a negative terminal, and the guide bar 2 is connected to the positive terminal and the negative terminal of two adjacent single cells 1 to connect the two adjacent single cells 1 in series, and the positive terminal of the single cell 1 at the end is connected to the total positive bus through the guide bar 2, and the negative terminal of the single cell 1 at the other end is connected to the total negative bus through the guide bar 2.

[0029] The end plate 3 is higher than the top of the single cell 1, so that the multiple single cells 1 are completely within the envelope formed by the end plate and the floor. In terms of power electrical interface, the total positive bus and the total negative bus are designed on the opposite side of the two end plates 3 of the battery module, and lead-out ports are opened on both sides, so that the total positive bus and the total negative bus extend through the lead-out ports to the opposite side of the end plate 3, realizing rapid series and parallel connection with other basic modules. Through the standardized design of the above mechanical and power electrical interfaces, different standard modules are spliced ​​to meet the needs of different battery packs.

[0030] The first ear piece 51 is fixedly connected to the side of one end plate 3 connected to the bottom plate away from the single battery 1, and the second ear piece 52 is fixedly connected to the side of the other end plate 3 connected to the bottom plate away from the single battery 1. When two adjacent battery pack units are connected, and the bottom plates of the two battery pack units are located on the same fixed plate, the first ear piece 51 of one battery pack unit and the second ear piece 52 of the other battery pack unit are just staggered, so that the bolt passes through the first ear piece 51 and the second ear piece 52 and is finally connected to the fixed plate.

[0031] like Figure 5 The figure shows a schematic diagram of further connecting two groups of 4 standard modules in series. The two groups of standard modules are mechanically connected through the first ear piece 51 and the second ear piece 52 on the end plates at both ends to form a series connection of standard modules in different directions. Figure 5 The total positive bus or total negative bus of the standard module can realize the quick connection of two sets of standard module power interfaces. In this way, the expansion connection of the battery pack can be realized in two dimensions. Through the splicing of standard modules, the design of large-scale satellite-borne battery packs can be realized.

[0032] The battery pack unit also includes a model battery. The model battery has the same structure as the single cell 1. When the model battery is connected to the single cell 1, the current of the single cell 1 can be extracted through the model battery. The model battery only acts as a conductor, but the model battery does not provide power.

[0033] The battery pack design of the present invention adopts the method of first connecting in series and then in parallel. Through the arrangement and combination of the above 4-series and 6-series standard battery modules, a series module is first formed to meet different voltage requirements, and then a parallel module is formed to meet different capacity requirements. It can be clearly seen that no matter how the battery pack is connected in series or in parallel, the current design can fully cover all current battery pack requirements, as shown below. Figure 3 As shown, when an N-parallel 7-string battery pack design is adopted, 4-string and 6-string standard modules can be used for building block combination to meet all battery pack designs from 1-parallel 7-string to 9-parallel 7-string. Specifically, for example, when 1 parallel to 7 strings is used, one single cell 1 in a battery pack unit having 4 single cells 1 connected in series (i.e., a 4-string battery pack unit) is replaced with a model battery to obtain an adjusted battery pack unit, and the adjusted battery pack unit is connected in series with a 4-string battery pack unit to obtain a 1 parallel to 7 string structure; for example, when 2 parallel to 7 strings is used, two 4-string battery pack units and a battery pack unit having 6 single cells 1 connected in series (i.e., a 6-string battery pack unit) are combined. When combined, the 4 single cells 1 connected in series of a 4-string battery pack unit are connected in series with the 3 single cells 1 connected in series of another 4-string battery pack unit through the positive and negative terminals of the single cells 1 to obtain a first group of 7 strings, and then the last single cell 1 of the 4-string battery pack unit is connected in series with the 6 single cells 1 connected in series of the 6-string battery pack unit to obtain a second group of 7 strings, and the first group of 7 strings and the second group of 7 strings are connected in parallel to obtain 2 parallel to 7 strings.

[0034] When the number of battery packs in series increases, the combination design can also be carried out through 4 strings and 6 strings of standard battery modules, as follows Figure 4 As shown, specifically, for example, when 8 strings are needed, two battery pack units with 4 series-connected single cells 1 are connected in series; for example, when 7 strings are needed, one single cell 1 in a battery pack unit with 4 series-connected single cells 1 is replaced with a model battery to obtain an adjusted battery pack unit, and the adjusted battery pack unit is connected with a battery pack unit with 4 series-connected single cells 1 to obtain a 7-string structure. It can be seen that the present invention provides an extremely efficient spatial modular lithium-ion battery pack structure, which greatly optimizes the current design of spatial lithium-ion batteries.

[0035] The contents not described in detail in this application specification belong to the common knowledge of those skilled in the art.

[0036] The present application is described in detail above in conjunction with specific implementation methods and exemplary examples, but these descriptions cannot be understood as limiting the present application. Those skilled in the art understand that, without departing from the spirit and scope of the present application, a variety of equivalent replacements, modifications or improvements can be made to the technical solution of the present application and its implementation methods, all of which fall within the scope of the present application. The scope of protection of the present application shall be subject to the attached claims.

Claims

1. A space efficient modular lithium ion battery pack structure, characterized in that: It includes at least one battery pack unit, and different battery pack units are connected in parallel or in series; Each battery pack unit comprises a bottom plate, an end plate (3), a tie rod (4) and a plurality of single cells (1); the end plate (3) is connected to two opposite ends of the bottom plate; the plurality of single cells (1) are mounted between the two end plates (3); the tie rod (4) is connected between the two end plates, and the tie rod (4) is in contact with one end of the single cell (1) facing away from the bottom plate, so as to fix the single cell (1) between the two end plates (3) and the bottom plate.

2. A space efficient modular lithium ion battery pack structure according to claim 1, characterized in that: The bottom plate is provided with a plurality of limiting grooves, and each single battery (1) has a protrusion at the bottom, and the protrusions are matched with the limiting grooves one by one, so that the bottoms of the plurality of single batteries (1) are clamped with the bottom plate.

3. The space-efficient modular lithium-ion battery pack structure according to claim 1, characterized in that: It also comprises a plurality of current guide bars (2), wherein the current guide bars (2) are connected to the positive electrode terminals and the negative electrode terminals of two adjacent single cells (1) so as to connect the two adjacent single cells (1) in series.

4. A space efficient modular lithium ion battery pack structure according to claim 3, characterized in that: A total positive bus and a total negative bus are respectively arranged on opposite sides of the two end plates (3); the positive electrode terminals of the single cells (1) at the end are connected to the total positive bus via a guide bar (2); and the negative electrode terminals of the single cells (1) at the other end are connected to the total negative bus via a guide bar (2).

5. A space efficient modular lithium ion battery pack structure according to claim 4, characterized in that: The end plate (3) is provided with an outlet port, so that the total positive bus and the total negative bus extend through the outlet port to opposite sides of the end plate (3), so that the battery pack units can be connected in series or in parallel through the total positive bus and the total negative bus.

6. A space efficient modular lithium ion battery pack structure according to claim 1, characterized in that: A first ear piece (51) is fixedly connected to one end plate (3) connected to the bottom plate on a side facing away from the single battery (1), and a second ear piece is fixedly connected to the other end plate (3) connected to the bottom plate on a side facing away from the single battery (1), and bolts pass through the first ear piece (51) and the second ear piece to connect and fix the first ear piece (51) and the second ear piece.

7. A space efficient modular lithium ion battery pack structure according to claim 6, characterized in that: The distances between the bottom surfaces of the first ear piece (51) and the second ear piece and the bottom surface of the bottom plate are different, wherein the ear piece with a larger distance from the bottom surface of the bottom plate is a high ear piece, and the ear piece with a smaller distance from the bottom surface of the bottom plate is a low ear piece; the bottom surface of the low ear piece is flush with the bottom surface of the bottom plate, and the distance between the bottom surface of the high ear piece and the bottom surface of the bottom plate is the thickness of the low ear piece.

8. The space-efficient modular lithium-ion battery pack structure according to claim 1, characterized in that: The battery pack unit also includes a model battery, which has the same appearance and structure as the single battery (1) but does not have the function of providing power; the model battery and the single battery (1) are both located between the two end plates (3).

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