Arrangement for quality testing of a battery cell

Abstract

Arrangement for quality testing of a battery cell (1), wherein the battery cell (1) has an outer skin formed from two sealed films and, within a space enclosed by the outer skin, an anode electrode, a cathode electrode, a separator separating the two electrodes and an ion-conducting electrolyte, wherein a connecting tab (2) connected to the anode electrode and a connecting tab (3) connected to the cathode electrode protrude through a sealing seam formed in the area of ​​the sealed films, wherein within the space enclosed by the outer skin, in a transparent area of ​​the outer skin, a device (4) is arranged which changes the optical appearance in the presence of a predetermined concentration of hydrogen fluoride in this space, and outside the outer skin an optoelectronic device (5) designed to detect the optical appearance is arranged.

Description

[0001] The invention relates to an arrangement for quality testing of a battery cell.

[0002] Such a battery cell is, in particular, a battery cell for use in a traction battery. German patent application DE 10 2013 016 618 A1 describes a battery cell comprising an outer shell formed from two sealed films and, within a space enclosed by the outer shell, an anode electrode, a cathode electrode, a separator separating the two electrodes, and an ion-conducting electrolyte. A connecting tab connected to the anode electrode and a connecting tab connected to the cathode electrode protrude through a sealing seam formed when the films are sealed. This battery cell is, in particular, a pouch cell.

[0003] From DE 197 02 855 A1 it is known to determine the liquid level inside an electrochemical cell using an optical sensor. This sensor is arranged inside the cell.

[0004] From US patent 2015 / 0303723A1, a fiber optic sensor for determining the state of charge of a battery is known.

[0005] US Patent 5,681,666 A describes a battery tester that has a moisture-resistant protective device with visual means for indicating battery status.

[0006] From DE 10 2008 001 707 A1, an energy storage device comprising an energy storage unit, for example a fuel cell or a battery unit, is known. This energy storage unit is surrounded by a casing containing a fluorine absorber. Toxic and volatile fluorine-containing compounds that may form in the event of a fire or overheating of the energy storage unit can thus be reduced or even avoided by using the fluorine absorber in the casing.

[0007] Battery cells, especially lithium-ion cells, are increasingly used as energy storage devices in electromobility. The materials used in the product are sensitive to moisture. Excessive moisture content in the materials can lead to undesirable reactions, such as the formation of hydrogen fluoride (HF). This can subsequently result in the battery cells failing to meet their technical specifications. The object of the present invention is to provide an arrangement that ensures non-destructive quality testing of a battery cell.

[0008] The problem is solved by an arrangement that has the features of claim 1.

[0009] The arrangement according to the invention serves for the quality control of a battery cell. This cell comprises an outer skin formed from two sealed films and, within a space enclosed by the outer skin, an anode electrode, a cathode electrode, a separator separating the two electrodes, and an ion-conducting electrolyte. A connecting tab connected to the anode electrode and a connecting tab connected to the cathode electrode protrude through the sealing seam formed during the sealing process. Within the space enclosed by the outer skin, specifically in a transparent area of ​​the outer skin, a device is arranged which changes the optical appearance in the presence of a predetermined concentration of hydrogen fluoride in this space. Outside the outer skin, an optoelectronic device is arranged for detecting the optical appearance of the device located within the enclosed space.

[0010] The battery cell is preferably a lithium-ion cell.

[0011] The battery cell is preferably a pouch cell.

[0012] It is specifically provided that the device arranged within the space is positioned near the seal seam. This device is thus located in a region of the space enclosed by the outer skin, representing a boundary area of ​​the battery cell with respect to the components arranged within the space, namely the two electrodes and the separator. In this boundary area, hydrogen fluoride preferably accumulates during its formation and can therefore be particularly well detected by means of the external optoelectronic device. The device arranged within the space is preferably a glass rod or a lithium metal plate. These are particularly suitable for changing their optical appearance in the presence of a predetermined concentration of hydrogen fluoride.

[0013] The device arranged within the space is preferably designed such that, in the presence of a predetermined, critical concentration of hydrogen fluoride, its optical appearance changes irreversibly.

[0014] The optoelectronic device is, in particular, a device for measuring a change in the reflectivity of the device arranged within space.

[0015] The optoelectronic device preferably detects the status of the optical appearance electrically or electronically.

[0016] In particular, an analysis system is provided for evaluating the status as a quality check and / or quality status.

[0017] The arrangement according to the invention thus enables non-destructive testing. This is carried out directly, quickly, unambiguously, and therefore reliably. The result is available promptly.

[0018] Further features of the invention will become apparent from the dependent claims, the accompanying drawing and the description of the embodiment shown in the drawing, without being limited thereto.

[0019] It shows: Fig. 1 in a schematic representation an arrangement for quality testing of a battery cell. Character description

[0020] A battery cell 1, a lithium-ion cell designed as a pouch cell, is illustrated. In a known manner, the battery cell 1 has an outer shell formed from two sealed films and, within a space enclosed by the outer shell, an anode electrode, a cathode electrode, a separator separating the two electrodes, and an ion-conducting electrolyte. A terminal 2 connected to the anode electrode and a terminal 3 connected to the cathode electrode protrude through the outer shell, particularly in the area of ​​a seal formed in the region of the sealed films.

[0021] Within the space enclosed by the outer skin, in a transparent area of ​​the outer skin, a device 4 is arranged. This device changes its optical appearance in the presence of a predetermined concentration of hydrogen fluoride in the space. The device 4 is located near the seal seam. This device 4 is a glass rod or a lithium metal plate. The device 4 is designed such that it irreversibly changes its optical appearance in the presence of a predetermined, critical concentration of hydrogen fluoride.

[0022] Outside the outer skin, i.e., the battery cell 1, an optoelectronic device 5 is arranged for detecting the optical appearance of the device 4 located in space.

[0023] Device 5 is a device for measuring a change in the reflectivity of device 4. Device 5 transmits the detected status of the optical appearance electrically or electronically to an analysis system 6, for evaluation of the status as a quality check and / or quality status.

[0024] The non-destructive testing of battery cell 1 is therefore direct, fast, unambiguous, and thus process-reliable. The result is available promptly.

Claims

[1] Arrangement for quality testing of a battery cell (1), wherein the battery cell (1) has an outer skin formed from two sealed films and, within a space enclosed by the outer skin, an anode electrode, a cathode electrode, a separator separating the two electrodes and an ion-conducting electrolyte, wherein a connecting tab (2) connected to the anode electrode and a connecting tab (3) connected to the cathode electrode protrude through a sealing seam formed in the area of ​​the sealed films, wherein within the space enclosed by the outer skin, in a transparent area of ​​the outer skin, a device (4) is arranged which changes the optical appearance in the presence of a predetermined concentration of hydrogen fluoride in this space, and outside the outer skin an optoelectronic device (5) designed to detect the optical appearance is arranged. [2] Arrangement according to claim 1, wherein the battery cell (1) is a lithium-ion cell. [3] Arrangement according to claim 1 or 2, wherein the battery cell (1) is a pouch cell. [4] Arrangement according to one of claims 1 to 3, wherein the device (4) arranged within the space is arranged near the sealing seam. [5] Arrangement according to any one of claims 1 to 4, wherein the device (4) arranged within the space is a glass pen or a lithium metal sheet. [6] Arrangement according to any one of claims 1 to 5, wherein the device (4) arranged within the space is designed such that this device (4) irreversibly changes its optical appearance in the presence of a predetermined, critical hydrogen fluoride concentration. [7] Arrangement according to any one of claims 1 to 6, wherein the optoelectronic device (5) is a device for measuring a change in a reflectivity of the device (4) arranged within the space. [8] Arrangement according to any one of claims 1 to 7, wherein the optoelectronic device (5) transmits the detected status of the optical appearance electrically or electronically. [9] Arrangement according to claim 8, wherein an analysis system (6) is provided for evaluating the status as a quality check and / or quality status.

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