EP3977552A1

EP3977552A1 - Goods carrier

Info

Publication number: EP3977552A1
Application number: EP20729709.4A
Authority: EP
Inventors: Ansgar VOM HEMDT; Hans HEIMES; Arne STOMMEL
Original assignee: Rheinisch Westlische Technische Hochschuke RWTH
Current assignee: Rheinisch Westlische Technische Hochschuke RWTH
Priority date: 2019-05-29
Filing date: 2020-05-28
Publication date: 2022-04-06
Also published as: WO2020239927A1; DE102019207945A1

Abstract

The invention relates to a goods carrier system comprising a goods carrier and comprising cell carriers for the formation of battery cells, said goods carrier having a guide device for receiving the cell carriers, wherein the cell carriers have contact elements for supplying an inserted battery cell with current, wherein the cell carriers can be clamped in the goods carrier, wherein connections for supplying cell carriers with current are brought together centrally on the goods carrier to form electrical connections.

Description

Goods carrier system

background

There are 3 common cell formats on the market: pouch cell, round cell and prismatic cell. Pouch cells have a flexible housing made of an aluminum-plastic composite film. Round cells have a cylindrical metal housing and prismatic cells have a prismatic metal housing. Basically, battery cell production can be divided into the following areas: electrode production, cell assembly (assembly of the cell) and cell conditioning. The production of electrodes hardly differs in terms of cell formats. The cell assembly and cell conditioning, however, show clear differences.

In the last part of cell production, lithium-ion battery cells go through the cell conditioning steps (synonyms: cell finishing, formation). The actual formation (the first charging and discharging of the cell) is only one sub-step in cell conditioning. In common parlance, however, “formation” is often used as a synonym for all steps. The exact sequence of the process sequence depends on the cell manufacturer. A possible reference sequence is shown below:

1. Process step: Pre-Aging: Process step in which the battery cell is stored in a chamber at room temperature or at an elevated temperature (approx. 45 ° C) for up to 24 hours. The aim of the process step is the homogeneous distribution of the electrolyte inside the cell. The battery cell is located in a product carrier (usually without a clamping device).

2. Process step: Formation (initial charge and discharge): Process step in which the battery cell is charged and discharged for the first time at room temperature or at an elevated temperature (approx. 45 ° C). Depending on the cell manufacturer, the battery cell is charged different times and at different speeds. The battery cells are located in a product carrier. In the case of pouch cells, the product carrier has a clamping device in order to exert a defined pressure on the cells (pouch cells do not have a rigid housing, which is why the anodes and cathodes in the cell can move away from each other. This is prevented by pressing). 3rd process step: degassing the cell. During the first charging and discharging processes, decomposition products are formed by the electrolyte. These collect in gaseous form in the cell. In the case of prismatic cells and pouch cells, these gases must be "vented".

4. Process step: Aging: Process step in which the battery cell is stored in a chamber at room temperature or at an elevated temperature (approx. 45 ° C) for up to 21 days. The battery cell is located in a product carrier (usually without a clamping device).

During the cell conditioning subsection, the battery cells can be located in product carriers and can be moved from one process step to the next. It is also known that the product carriers can exert pressure on pouch cells.

The process section of cell conditioning is considered to be time-consuming, cost-intensive and inflexible in terms of cell geometries and formats. This is due in particular to the fact that each battery cell format requires specifically adapted system technology. The battery cells have to be electrically contacted in a complex manner within the system, since, depending on the respective battery cell, the connections are arranged at different spatial positions and the connections themselves may also have different geometries.

As a result, a separate production line is required for practically every battery cell format. However, this also involves investment costs. In addition, however, there are also high operating costs. The provision of our own production lines also means that there is a high space requirement.

Further problems with the previous systems are the need for complex temperature regulation for the individual process steps that require heating or cooling. The maintenance of the contact elements represents a further problem, since changing a single contact element hinders continued operation.

The previous implementation is inflexible and expensive, the cells are contacted via the shelf or chamber, which is why this is only suitable for special geometry and a single cell format. Formation and aging take place in different rooms, which are tempered accordingly, since during formation heat has to be dissipated, whereas during aging heat has to be added. The indirect heating / dissipation of heat from rooms or chambers requires a lot of energy. In addition, with indirect heating / Cooling can also be expected with longer process times. This means that new shelves / chambers have to be purchased for each cell variant, which is associated with enormous investments

task

Against this background, it is an object of the invention to provide an improved goods carrier system for cell production which solves one or more disadvantages of the prior art.

solution

The object is achieved by means of a goods carrier system according to claim 1. Further advantageous refinements of the invention are given in the respective dependent claims, the description and in the figures.

Brief presentation of the figures

The invention is explained in more detail below with reference to the attached drawings using preferred embodiments.

Show it

1 shows a perspective illustration of a goods carrier system with cell carriers according to embodiments of the invention, FIG. 2 shows a perspective illustration of a goods carrier system with cell carriers with inserted battery cells according to embodiments of the invention, 3 shows a perspective illustration of a cell carrier according to embodiments of the invention, and

4 shows a perspective illustration of a heat sink assembly of a cell carrier according to embodiments of the invention.

The invention is illustrated in more detail below (with reference to the figures). It should be noted that different aspects are described that can be used individually or in combination. I.e. any aspect can be used with different embodiments of the invention, unless explicitly shown as a pure alternative.

Furthermore, for the sake of simplicity, reference will generally only be made to one entity in the following. Unless explicitly stated, the invention can also have several of the entities concerned. In this respect, the use of the words “a”, “an” and “an” is to be understood only as an indication that at least one entity is used in a simple embodiment.

Insofar as methods are described below, the individual steps of a method can be arranged and / or combined in any order, unless the context explicitly results in something different. Furthermore, the processes can be combined with one another - unless expressly stated otherwise.

Figures with numerical values are generally not to be understood as exact values, but also include a tolerance of +/- 1% up to +/- 10%.

References to standards or specifications or norms are to be understood as referring to standards or specifications or norms that apply at the time of application and / or - if a priority is claimed - at the time of priority application. However, this is not to be understood as a general exclusion of applicability to the following or replacement standards or specifications or norms. In the following, “adjacent” explicitly includes an immediate neighborhood relationship without, however, being restricted to this. In the following, "between" explicitly includes a position in which the intermediate part is in direct proximity to the surrounding parts.

In Figures 1 and 2, a goods carrier system with a goods carrier with inserted cell carriers is shown.

The reference symbol K represents a heat sink face plate. The heat sink face plate K is preferably made of a thermally conductive material, e.g. a metal / metal alloy, e.g. Aluminum or copper.

In embodiments of the invention, a force measuring device (e.g. a pressure sensor) can be arranged on one or more heat sink front plate (s) (each) K or on an inside of an outer wall 3 or 4 of the goods carrier. For example, a force measuring device can be arranged on the heat sink end plate K shown at the rear or on the inside of the outer wall. The tension can be measured by means of the force measuring device. This allows the tension of inserted battery cells Z to be set in a targeted manner. In addition, the change in the forces can be monitored in the course of the process and readjustment can be made if necessary.

Reference symbol K 'denotes a heat sink. The heat sink K ^' is preferably made from a thermally conductive material such as a metal / metal alloy such as aluminum or copper.

A thread can be provided in the heat sink K '. Heat sink K ^' and heat sink end plate K can be understood as an example of a cooling element. The cooling element can have further elements for cooling, such as a pipe R or a pelletizing element, with which heat can be actively supplied and removed.

The reference character A denotes a suspension. A suspension is also designated by reference character A '. Suspension A can differ from suspension A 'in that suspension A' has a contact surface, while suspension A has no contact surface.

Reference numeral 2 denotes a bearing rod. The cell carriers can be arranged on bearing rods 2.

The goods carrier also has a first outer wall 3 and a second outer wall 4. Electrical connections EV are provided at least in one of the outer walls 3, 4. In the example of the figures, electrical connections EV are provided in the first outer wall. The outer walls 3 and 4 together with the bearing rods 2 and a spindle 9 (e.g. a trapezoidal spindle) result in mechanical rigidity, so that the inserted cell carriers with the respective inserted battery cells can be positioned torsion-resistant.

I.e. Bearing rods 2 form a guide device for receiving the cell carriers.

The cell carrier has contact elements for energizing an inserted battery cell Z.

These can be provided, for example, by the spring contact pins KS or contact socket KB. The contact elements for energizing battery cells Z can be brought together centrally on the goods carrier to form one or more electrical connections EV.

In addition, the goods carrier can have a base plate 6.1.

A cell carrier can furthermore have a spindle mount 7. The spindle seat 7 can be made of a suitable material, e.g. Brass. A spindle 9 can be accommodated in the spindle receptacle 7. Brass can advantageously be inserted because of its friction properties.

The spindle 9 is guided in a spindle nut 8 in the goods carrier.

Furthermore, one or more pipe distributors 10 can also be arranged in the outer wall 4. During operation, the pipe distributors 10 can provide a fluidic connection to cooling pipes R in the cooling bodies K, which are shown in detail in FIGS. 3 and 4.

The inserted battery cells can be pressed together with a defined force by the spindle 9. The cell carriers are advantageously arranged so as to be steplessly displaceable on the linear shafts 2. The cell carrier is formed from two heat sinks K and K ‘, between which a battery cell Z can be accommodated. The battery cells Z can be compressed with a defined force by the spindle 9.

The inserted battery cells Z are contacted by the cell carriers and thus independently of the formation chamber. The cell contact can be made by spring contact pins KS (shown in Figure 4). In an advantageous embodiment, the spring contact pins KS are easily exchangeable, so that downtimes can be reduced or reduced to individual (exchangeable) cell carriers. Since the contact is integrated in the product carrier, the spring contact pins can be simply exchanged in the event of wear take place in the goods carrier when it is not in use. This means that the system technology is not put out of operation during maintenance.

The heat transport required during a formation of battery cells can be made available through the cooling tubes R within the cooling body K. It should be noted that, as an alternative or in addition to liquid cooling, gas cooling or pelletizing elements can also be inserted.

However, liquid cooling is preferred. The pipelines R can be shaped as independent tubes (as shown), or worked into a material as a fluid channel (e.g. milled) or stamped (pressed). In a preferred embodiment, the pipes R have copper.

The integrated cooling makes it possible to transport heat away directly to the battery cells Z. Removed heat can be used in the same way in other production steps (e.g. preaging) in which heat is required in the same goods carrier system. If the goods carrier is used in preaging, the battery cells Z can also be heated via the pipes R. The main advantage here is that the heat source is then closer to the battery cells Z and is not heated by the room air.

In embodiments of the invention it can be provided that the heat sink K or K1 has one (or more) thermal sensor elements T, for example a temperature-dependent resistor or a temperature-dependent semiconductor element or a thermocouple (PT100 or the like). With such a thermal sensor element, it is possible to determine the temperature of an individual product carrier or a heat sink that is part of a product carrier. The determined temperature can be used to control the temperature of an individual carrier. As an alternative or in addition, however, it is also possible to use the temperature (or its profile) to control currents in a specific battery cell Z. Due to the separate provision of cooling and contacting, these variables are now independent of the formation shelf. This increases the flexibility considerably.

Depending on the format and geometry of the battery cell Z, only different product carriers are required. The system technology can therefore be used for all formats and geometries. As a result, the cost of the system technology is reduced considerably by making the invention more flexible.

In contrast to conventional formation systems in which the battery cells are connected in series during formation, in the embodiments of the invention the inserted battery cells Z in a cell carrier can be controlled individually or in groups, i.e. be supplied with electricity.

If a battery cell Z fails, the formation of the remaining battery cells Z can be continued. This can massively reduce scrap

Furthermore, with embodiments of the invention it is possible to use different battery cells Z with regard to their electrochemical properties, e.g. different voltages, and / or different capacities, etc., to form simultaneously in a common goods carrier, since different currents and / or voltages (different from 0 V or 0 A) can be conducted to the respective battery cells Z.

This can further increase the flexibility.

By using ball bearings in the bracing elements of the goods carrier, the movement of the elements is very robust. This makes it easy for the goods carriers to slide on the spindles 9, so that blockages cannot occur. The illustrated invention eliminates the problems listed above by presenting a robust goods carrier concept that has integrated contacting and thermal management.

Depending on the cell format and geometry, only different goods carriers are required. The system technology, however, can be used for all cell formats and geometries. The system technology is typically in the range of several hundred thousand euros and a product carrier in the range of a few thousand euros. The costs for the flexibility with the presented invention are correspondingly lower.

Cell carriers for different battery cell formats can also be accommodated in one product carrier.

Claims

Requests

1. Goods carrier system with a goods carrier and with cell carriers for the formation of battery cells, the goods carrier having a guide device for receiving the cell carriers, the cell carriers having contact elements for energizing an inserted battery cell, wherein the cell carriers can be clamped in the goods carrier, with connections for energizing cell carriers are brought together centrally on the goods carrier to form electrical connections, a first cell carrier being suitable for a first battery cell format and a second cell carrier being suitable for a second battery cell format, with both the first cell carrier and the second cell carrier having a thermal sensor element, the temperature and / or the temperature profile is used to control currents in an inserted battery cell.

2. Goods carrier system according to claim 1, characterized in that the cell carrier has a cooling element in order to be able to dissipate heat which can arise when an inserted battery cell is energized.

3. Goods carrier system according to claim 1 or 2, characterized in that at least one cell carrier has a thermal sensor element.

4. Goods carrier system according to one of the preceding claims, characterized in that cell carriers for different battery cell formats can be accommodated in a goods carrier.

5. Goods carrier system according to one of the preceding claims, characterized in that the goods carrier has a force measuring device so that the tension can be measured.

6. Goods carrier system according to one of the preceding claims, characterized in that the contact elements have spring contact pins.

7. Goods carrier system according to one of the preceding claims, characterized in that a cell carrier has liquid cooling.

8. Goods carrier system according to one of the preceding claims, characterized in that inserted battery cells Z are controlled individually or in groups in a cell carrier.

9. Goods carrier system according to one of the preceding claims, characterized in that different battery cells Z in a common goods carrier with different voltages and / or currents can be formed at the same time.