DE-102024132972-A1 - Holding device for battery cells and method for manufacturing an energy storage device

Abstract

The disclosure relates to a holding device (4) for holding a plurality of battery cells (2) of an energy storage device, in particular a high-voltage storage device, which is movable between an assembly state and an installation state, wherein a first distance (d1) of adjacent battery cells (2) in the assembly state is greater than a second distance (d2) of adjacent battery cells (2) in the installation state, and a method for manufacturing an energy storage device.

Inventors

• Attila Farkas

Assignees

• BAYERISCHE MOTOREN WERKE AKTIENGESELLSCHAFT

Dates

Publication Date

20260513

Application Date

20241112

Claims (9)

1. Holding device (4) for holding a plurality of battery cells (2) of an energy storage device, in particular a high-voltage storage device, which is movable between an assembly state and an installation state, characterized in that a first distance (d1) of adjacent battery cells (2) in the assembly state is greater than a second distance (d2) of adjacent battery cells (2) in the installation state.
2. Holding device (4) according to Claim 1 , characterized in that the assembly state and the installation state form stable states of the holding device (4).
3. Holding device (4) according to Claim 1 or 2 , characterized in that the holding device (4) has a plurality of battery cell holding sections (6) on each of which a battery cell (2) can be received/received.
4. Holding device (4) according to Claim 3 , characterized in that each battery cell holding section (6) has two fastening sections (8) for fastening the battery cell (2) to the battery cell holding section (6), which are connected via two leg sections (10).
5. Holding device (4) according to Claim 4 , characterized in that the leg sections (10) are each designed in the manner of a bistable spring.
6. Holding device (4) according to one of the preceding Claims 1 until 5 , characterized in that the second distance (d2) is greater than zero in the installed state, so that in the installed state there is an air gap between adjacent battery cells (2).
7. Holding device (4) according to Claim 6 , characterized in that the battery cell holding sections (6) are each spaced apart from each other by a spacer section (16) which ensures the air gap between the adjacent battery cells (2).
8. Holding device (4) according to one of the preceding Claims 1 until 7 , characterized in that the holding device (4) is made of a plastic.
9. Method for manufacturing an energy storage device, in particular a high-voltage storage device, comprising the following steps: - Providing a holding device (4), preferably according to one of the preceding Claims 1 until 8 , in an assembly state; - Mounting the holding device (4) with a plurality of battery cells (2); - Moving the holding device (4) mounted with the plurality of battery cells (2) from the assembly state to an installation state; - Mounting the holding device (4) together with the plurality of battery cells (2) into a battery cell housing of the energy storage device.

Description

The disclosure relates to a holding device for holding a plurality of battery cells of an energy storage device, in particular a high-voltage storage device, which is movable between an assembly state and an installation state. Background of the Revelation An energy storage system/battery storage system/high-voltage storage system in a hybrid or electric vehicle is an energy storage system that stores electrical energy in the form of direct current at high voltage. This stored energy is typically used to power at least one of the vehicle's electric motors. These high-voltage storage systems are typically composed of individual battery cells, such as lithium-ion cells, or modules configured in a battery pack. Such battery packs are typically assembled sequentially, meaning they are built up row by row, regardless of the cell format. With prismatic cells, a row can consist of just one very wide cell. Alternatively, a row can be made up of several (narrower) cells. With cylindrical cells, a row conventionally consists of cells bonded together with a heat sink. The individual cell rows are attached sequentially to an already bonded cell or cell row, so that the battery pack grows with each step or cell row until the desired number of rows is reached. However, this sequential assembly involves a high number of repeatable steps and is therefore very time-consuming. Assembly aids/holding devices are already known in the prior art, which enable almost simultaneous assembly of the cell rows. For example, the DE 10 2021 122 739 A1 a method for manufacturing an energy storage device in which a structural component is provided in which the battery cells can be arranged and/or positioned simultaneously. Another challenge in the assembly of prismatic battery cells, in particular, is the swelling of the battery cells during operation and/or over their lifetime (so-called "cell swelling"). To counteract this effect, an air gap must be maintained between adjacent battery cells to allow for expansion. Spacers are therefore used between the battery cells to ensure this air gap. DE 10 2020 110 637 A1 For example, a tensioning element is shown which is arranged between adjacent battery cells and expands in an installed state of the battery cells in a housing of the energy storage device in order to push the battery cells apart and maintain the air gap. Summary of Revelation The tasks and objectives of this disclosure are to eliminate or at least mitigate the disadvantages of the prior art and, in particular, to provide a cost-effective holding device for a plurality of battery cells, which enables the parallel assembly of several cell rows and thus saves time. At the same time, the holding device should also ensure the air gap between the battery cells when assembled. The tasks and objectives with regard to a generic holding device are solved, as disclosed, by the subject matter of claim 1. The disclosure is thus based on the knowledge of a one-piece/one-piece holding device which is used during assembly and is simultaneously part of the energy storage device. The holding device is accordingly configured/adapted as disclosed such that a first distance between adjacent battery cells in the assembled state is greater than a second distance between adjacent battery cells in the installed state. In the assembled state, the battery cells are therefore spaced further apart than in the installed state. Consequently, the holding device ensures good accessibility in the assembled state, allowing the battery cells to be mounted simultaneously and thus quickly. In the installed state, the battery cells are closer together, which enables a high energy density in the energy storage device. Advantageous embodiments are claimed in the dependent claims and are explained below. In a preferred embodiment, the assembly state and the installation state can constitute stable states of the holding device. A stable state represents an equilibrium position of the holding device, from which the holding device can only be released by applying an external force. In other words, the holding device remains in the stable states, namely the assembly state and the installation state, until an external force pushes/moves it out of this stable state. According to an advantageous embodiment, the holding device can have a plurality of battery cell holding sections, each of which can accommodate a battery cell. Preferably, each battery cell holding section can have two fastening sections for attaching the battery cell to the holding section. The fastening sections can be connected to each other via two leg sections. Particularly preferably, the leg sections can each be designed in the manner of a bistable spring (click spring). The leg sections can therefore have a first stable state and a second stable state. The first stable state of the leg sections can correspond to the assembly state, whereas the second stable state of the leg sections represents the installe