ENERGY STORAGE SYSTEM WITH AT LEAST ONE ENERGY STORAGE CELL FOR STORING ELECTRICAL ENERGY AND METHOD FOR PRODUCING SUCH AN ENERGY STORAGE SYSTEM

Abstract

The invention relates to an energy storage system (1) with at least one energy storage cell (2) for storing electrical energy, wherein the energy storage cell (2) has at least one contract terminal (3), in particular in the form of a connection pole, and wherein the at least one energy storage cell (2) is assigned a carrier (4), in particular in the form of a printed circuit board, wherein the at least one contract terminal (3) of the energy storage cell (2) is galvanically connected, in particular, to a conductor track of the carrier (4) via a soldered connection, and wherein an adhesive layer (5) is formed at least partially or regionally between the energy storage cell (2) and the carrier (4), via which adhesive layer the energy storage cell (2) is integrally connected to the carrier (4).

Description

[0001] The present invention relates to an energy storage system having at least one energy storage cell for storing electrical energy. According to a further aspect, the invention relates to a method for producing such an energy storage system.

[0002] Energy storage systems of the type considered herein are used in many fields of technology. The present invention relates in particular to the field of energy storage systems for vehicles, which may be aircraft or watercraft, rail-guided vehicles, or preferably road vehicles. Road vehicles are understood to mean, in particular, passenger cars, trucks, buses, or mobile homes.

[0003] The document DE 10 2020 130 751 A1 relates to a battery arrangement with at least one battery cell, a method for producing such a battery arrangement and methods for connecting, disconnecting and replacing a battery cell.

[0004] The document DE 10 2021 123 246 A1 relates to a battery arrangement comprising a plurality of energy storage cells, wherein the energy storage cells have connection poles to which cell connectors are fastened, in particular welded, for interconnecting the energy storage cells, thereby forming fastening points (60), and wherein the energy storage cells are connected to a contacting system formed by a printed circuit board having a cover layer on both sides. In particular, it is provided that the printed circuit board is arranged between the connection poles and the cell connectors in such a way that the fastening points, in particular the welds, via which the cell connectors are indirectly connected to the connection poles via the printed circuit board, are protected from external influences by the cover layers.

[0005] As part of the effort to optimize the energy balance of vehicles, especially road vehicles, and to reduce fuel consumption, existing batteries are being incorporated into various concepts, for example, in start / stop systems or energy recovery during braking. Vehicles are also increasingly equipped with on-board systems that require electrical power.

[0006] Lead-acid batteries are typically used as starter batteries, but their low energy density makes them heavy. Lithium-ion batteries, on the other hand, have a relatively high energy density. Lithium-ion batteries also offer, for example, a longer service life, lower self-discharge, improved rapid charging capability, and shorter maintenance intervals compared to conventional lead-acid batteries.

[0007] Overall, new requirements exist for energy storage systems, especially accumulators, that go beyond the previous requirement of being suitable for starting an internal combustion engine. At the same time, modern energy storage systems that meet the new requirements should have as similar a footprint as existing accumulators, meaning no additional installation space should be consumed, and the external dimensions should be retained as much as possible. Overall, particularly due to the growing number of energy consumers, ever-increasing demands are being placed on the performance, weight, reliability, and manufacturing costs of energy storage systems in vehicles.

[0008] The invention is therefore based on the object of specifying an energy storage system with one or more energy storage cells for storing electrical energy, which offers improved properties for the aforementioned novel vehicle concepts with comparable external dimensions.

[0009] In particular, the invention is based on the object of designing an energy storage system for series production, especially large-scale production, more efficiently, particularly with regard to automated manufacturing processes in automotive applications. Furthermore, an improved method for assembling such energy storage systems is to be provided.

[0010] With regard to the energy storage system, the object underlying the invention is achieved by the subject matter of independent patent claim 1, wherein advantageous developments of the energy storage system according to the invention are specified in dependent claims 2 to 9.

[0011] With regard to the manufacturing method, the object underlying the invention is achieved by the subject matter of the independent patent claim 10, wherein advantageous developments of the method according to the invention are specified in the dependent claims 11 and 12.

[0012] Accordingly, the invention relates in particular to an energy storage system comprising at least one energy storage cell for storing electrical energy, wherein the energy storage cell has at least one contract terminal, in particular in the form of a connection pole, and wherein a carrier, in particular in the form of a printed circuit board, is assigned to the at least one energy storage cell. It is provided that the at least one contract terminal of the energy storage cell is galvanically connected, in particular, to a conductor track of the carrier or the printed circuit board via a solder connection.

[0013] In order to optimize the mechanical connection between the energy storage cell and in particular the carrier designed as a printed circuit board, the invention provides that an adhesive layer is formed at least partially or regionally between the energy storage cell and the carrier, via which adhesive layer the energy storage cell is integrally connected to the carrier.

[0014] The adhesive layer formed between the energy storage cell and the carrier performs a dual function: Firstly, the integral bond optimizes the mechanical connection provided by the solder joint between the energy storage cell and the carrier, which is often designed as a printed circuit board, eliminating the need for additional connections or frame elements. Secondly, the adhesive layer also serves as an insulator to electrically isolate the conductor tracks of the carrier, which is often designed as a printed circuit board, from the energy storage cell.

[0015] According to implementations of the energy storage system according to the invention, it is provided that the carrier has an upper side facing the at least one storage cell and a lower side opposite the upper side, wherein at least one soldering eye or at least one soldering surface, in particular a soldering pad, is provided at least on the upper side of the carrier, via which or via which of the at least one contract terminal of the energy storage cell is galvanically connected in particular to the conductor track of the carrier.

[0016] This design variant has the advantage that the galvanic connection between the at least one contract terminal of the energy storage cell and the soldering pad or soldering surface of the carrier can be made using a dip soldering or wave soldering process. This allows for particularly efficient production of the energy storage system. Of course, other soldering processes are also possible.

[0017] The at least one soldering pad or the at least one soldering surface is designed in particular to mechanically hold and electrically connect the energy storage cell via the contract terminal which is galvanically connected in particular to the conductor track of the carrier.

[0018] According to preferred implementations of the energy storage system, it is provided that the carrier has a through-opening or bore in the region of the at least one energy storage cell, via which the adhesive material required to form the adhesive layer is introduced or can be introduced into the region between the carrier and in particular between the upper side of the carrier and the energy storage cell during the manufacture of the energy storage system.

[0019] By providing such a through-hole or bore, the adhesive material can penetrate from the back of the carrier into the area between the energy storage cell and the carrier. This allows for complete automation of the manufacturing process.

[0020] It is preferred that the through-opening or bore on the upper side of the carrier opens into a region which is preferably centrally and in particular substantially centrally aligned with an end face of the energy storage cell.

[0021] This design variant has the advantage that the adhesive layer can be formed only locally in the form of adhesive pads. This saves material (adhesive material) and reduces the overall weight of the energy storage system.

[0022] In this context in particular, it is advisable that, if the energy storage cell has several contract terminals, a central region of the adhesive layer is formed equidistant from the at least two contract terminals in order to form a uniform material connection between the energy storage cell and the carrier.

[0023] In order to effectively achieve electrical insulation with the aid of the adhesive layer, a distance between the carrier and in particular the upper side of the carrier facing an end face of the energy storage cell and the energy storage cell and in particular the end face of the energy storage cell should be at least 1 mm, preferably at least 2 mm and more preferably at least 3 mm.

[0024] The energy storage system according to the invention is particularly suitable for applications in which a supercap (supercapacitor) or ultracap (ultracapacitor) is used as the energy storage cell.

[0025] Such energy storage cells are characterized by excellent properties, in particular high cycle stability, long life expectancy, wide temperature range, high power density, high energy efficiency, high vibration resistance, high acceleration forces, and freedom from maintenance.

[0026] Of course, the invention is not limited to supercapacitors or ultracapacitors as energy storage cells. In other words, the invention also relates to energy storage systems in which the at least one energy storage cell is embodied as an electrochemical accumulator. A suitable electrochemical accumulator is, in particular, a lithium-ion battery, a lithium-polymer battery, but also a nickel-cadmium battery or a nickel-metal hydride battery.

[0027] Preferably, the at least one energy storage cell is connected to a battery management system via the carrier, which is designed in particular as a printed circuit board.

[0028] It is advisable for the carrier itself to be part of a battery management system assigned to the energy storage system.

[0029] The battery management system is an electronic circuit used to monitor and control the performance, safety, and service life of the individual energy storage cells in the energy storage system. The battery management system monitors key parameters such as the SoC (state of charge), voltage, current flow, and temperature of the individual energy storage cells and the entire energy storage system. This data is used to optimize the performance of the energy storage system and to detect and, if necessary, correct potential problems.

[0030] In the manufacturing method according to the invention, at least one energy storage cell and a carrier, in particular in the form of a printed circuit board, are first provided. Subsequently, the at least one contract terminal of the energy storage cell is electrically connected to a soldering pad or a soldering surface of the carrier by soldering.

[0031] Thereafter, a plastic material is introduced into a space between a surface of the carrier facing the energy storage cell and an end face of the energy storage cell facing the surface of the carrier.

[0032] In particular, it is provided in this context that the plastic material is introduced into the space between the surface of the carrier facing the energy storage cell and the end face of the energy storage cell facing the surface of the carrier in such a way that an adhesive layer is formed at least partially or regionally between the energy storage cell and the carrier, via which the storage cell is materially connected to the carrier and via which the energy storage cell is electrically insulated from the carrier.

[0033] As with the energy storage system according to the invention, it is suitable in the manufacturing method according to the invention that the plastic material is injected from a bottom side of the carrier facing away from the energy storage cell surface of the carrier via a through opening or bore in the carrier into the space between the carrier and the energy storage cell.

[0034] The invention is described in more detail below with reference to the accompanying drawings.

[0035] They show: Fig. 1 schematically and in an isometric view, a region of an exemplary embodiment of the energy storage system according to the invention, specifically a number of energy storage cells which are connected both galvanically via solder joints and materially via adhesive joints to a printed circuit board serving as a carrier; Fig. 2 schematically and in an isometric view a portion of the energy storage system according to Fig. 1 before the galvanic and material-locking connection of the energy storage cells to the circuit board; Fig. 3 schematically and in an isometric view the area of ​​the energy storage system according to Fig. 2 after galvanically connecting the contract terminals of the energy storage cells with the corresponding solder pads of the circuit board; Fig. 4 schematically and in an isometric view the process of injecting adhesive material from the outside of the circuit board into the area between the respective end faces of the energy storage cells and the circuit board; Fig. 5 schematically and in an isometric view the area between the end face of an energy storage cell and the circuit board after the introduction of the plastic material according to Fig. 4; and Fig. 6 schematically and in a partially sectioned view the area between the end face of an energy storage cell and the conductor plate after penetration of the plastic material.

[0036] The energy storage system 1 shown in the drawings comprises a plurality of energy storage cells 2, which in the exemplary embodiment are designed as supercapacitors (supercapacitors) and each have a total of four contract terminals 3 on one end face of the energy storage cell 2. The respective energy storage cells 2 are galvanically connected to corresponding conductor tracks of a printed circuit board 4 via the contract terminals 3 using solder joints. This is preferably done by dip soldering or wave soldering.

[0037] In order to improve / reinforce the solder connection between the energy storage cells 2 and the circuit board 4, an adhesive layer 5 is formed between each energy storage cell 2 and the circuit board 4, via which adhesive layer 5 the corresponding energy storage cell 2 is firmly connected to the circuit board 4.

[0038] In particular, the representations in Fig. 1 and Fig. 2 that the printed circuit board 4 has an upper side 6 facing the energy storage cells 2 and a lower side 7 opposite the upper side 6, wherein the printed circuit board 4 has corresponding soldering pads 9 or soldering surfaces via which the individual contract terminals 3 of the energy storage cells 2 are galvanically connected to conductor tracks of the printed circuit board 4.

[0039] The representation in Fig. 2 it can further be seen that the carrier or the printed circuit board 4 in the area of ​​each energy storage cell 2 has a through-opening 8 in the form of a bore, through which the adhesive material required to form the adhesive layer 5 is introduced into the area between the printed circuit board 4 and in particular the top side 6 of the printed circuit board 4 and the respective energy storage cells 2 during the manufacture of the energy storage system, as in Fig. 4 indicated.

[0040] The invention is not limited to the exemplary embodiment shown in the drawings, but results from a combination of all features disclosed herein. List of reference symbols 1 energy storage system 2 energy storage cells 3 Contract terminal 4 carrier / circuit board 5 Adhesive layer 6 Top of the carrier 7 Underside of the carrier 8 Through hole / bore 9 soldering pad

Claims

[1] Energy storage system (1) with at least one energy storage cell (2) for storing electrical energy, wherein the energy storage cell (2) has at least one contract terminal (3), in particular in the form of a connection pole, and wherein the at least one energy storage cell (2) is assigned a carrier (4), in particular in the form of a printed circuit board, wherein the at least one contract terminal (3) of the energy storage cell (2) is galvanically connected, in particular, to a conductor track of the carrier (4) via a soldered connection, and wherein an adhesive layer (5) is formed at least partially or regionally between the energy storage cell (2) and the carrier (4), via which adhesive layer the energy storage cell (2) is integrally connected to the carrier (4). [2] Energy storage system (1) according to claim 1, wherein the carrier (4) has an upper side (6) facing the at least one energy storage cell (2) and a lower side (7) opposite the upper side (6), wherein at least on the upper side (6) of the carrier (4) at least one soldering eye (9) or at least one soldering surface, in particular a soldering pad, is provided, via which the at least one contract terminal (3) of the energy storage cell (2) is galvanically connected in particular to the conductor track of the carrier (4). [3] Energy storage system (1) according to claim 2, wherein the at least one soldering pad (9) or the at least one soldering surface is designed to mechanically hold and electrically connect the energy storage cell (2) via the contract terminal (3) which is galvanically connected in particular to the conductor track of the carrier (4). [4] Energy storage system (1) according to one of claims 1 to 3, wherein the carrier (4) has a through-opening (8) or bore in the region of the at least one energy storage cell (2), via which the adhesive material required to form the adhesive layer (5) was introduced into the region between the carrier (4) and in particular between the upper side (6) of the carrier (4) and the energy storage cell (2) during the manufacture of the energy storage system (1). [5] Energy storage system (1) according to claim 4, wherein the through-opening (8) or bore on the upper side (6) of the carrier (4) opens into a region which is preferably centrally and in particular at least substantially centrally aligned with an end face of the energy storage cell (2). [6] Energy storage system (1) according to one of claims 1 to 5, wherein the at least one energy storage cell (2) has at least two contract terminals (3), in particular each in the form of a connection pole, wherein a central region of the adhesive layer (5) is formed equidistant from the at least two contract terminals (3). [7] Energy storage system (1) according to one of claims 1 to 6, wherein a distance between the carrier (4) and in particular an upper side (6) of the carrier (4) facing an end face of the energy storage cell (2) and the energy storage cell (2) and in particular the end face of the energy storage cell (2) is at least 1 mm, preferably at least 2 mm and more preferably at least 3 mm. [8] Energy storage system (1) according to one of claims 1 to 7, wherein the at least one energy storage cell (2) is designed as a supercap or ultracap; or wherein the at least one energy storage cell (2) is designed as an electrochemical accumulator. [9] Energy storage system (1) according to one of claims 1 to 8, wherein the carrier (4) is part of a battery management system associated with the energy storage system (1). [10] Method for producing an energy storage system (1), in particular an energy storage system (1) according to one of claims 1 to 9, wherein the method comprises the following method steps: (a) providing at least one energy storage cell (2) and a carrier (4), in particular in the form of a printed circuit board; (b) electrically connecting at least one contract terminal (3) of the energy storage cell (2) to a soldering pad (9) or a soldering surface of the carrier (4) by soldering; and (c) introducing a plastic material into a space between a surface of the carrier (4) facing the energy storage cell (2) and an end face of the energy storage cell (2) facing the surface of the carrier (4). [11] Method according to claim 10, wherein in step (c) the plastic material is introduced into the space between the surface of the carrier (4) facing the energy storage cell (2) and the end face of the energy storage cell (2) facing the surface of the carrier (4) in such a way that an adhesive layer (5) is formed at least partially or regionally between the energy storage cell (2) and the carrier (4), via which adhesive layer the energy storage cell (2) is integrally connected to the carrier (4). [12] Method according to claim 10 or 11, wherein in step (c) the plastic material is injected from an underside (7) of the carrier (4) facing away from the surface of the carrier (4) facing the energy storage cell (2) via a through-opening (8) or bore in the carrier (4) into the space between the surface of the carrier (4) facing the energy storage cell (2) and the end face of the energy storage cell (2) facing the surface of the carrier (4).

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