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CN-122003758-A - Energy storage element, cover assembly and manufacturing method

CN122003758ACN 122003758 ACN122003758 ACN 122003758ACN-122003758-A

Abstract

An energy storage element (100) includes an electrode-separator assembly (104) having an anode (105)/separator (156)/cathode (108) in a sequential arrangement having a first end face (104 a) and a second end face (104 b). It further comprises a contact sheet metal member (112) resting on a longitudinal edge (106 a,109 a) of the current collector (106, 109) of one of the electrodes, covering one of the end faces (104 a,104 b) and being connected to this longitudinal edge. An electrode-membrane assembly (104) is arranged in the interior space of a gas-and liquid-tight closed housing comprising a metal housing cup (101) with a terminal circular opening and a cover (102) with a circular rim (102 a) closing the circular opening. The cover (102) is preferably formed as a cover assembly comprising a metal disc (113) having a circular rim, wherein the metal disc (113) has an inner side defining an inner space. It is proposed that the contact sheet metal component (112) comprises a distance compensation region (112 d) connected to the inner side of the metal disc (113) in a connection region (112 e). Alternatively, a distance compensating sheet metal member (177) may be provided, which is welded to the contact sheet metal member (112), wherein the distance compensating sheet metal member (177) comprises a distance compensating region (177 a) connected to the inner side of the metal disc (113) in a connection region (177 b). The connection between the distance compensation area (177 a) and the inner side of the metal disc (113) may be formed after the housing has been closed.

Inventors

  • D Kissinger
  • M. GEIGER
  • W. FRANK
  • V. Druce's

Assignees

  • 瓦尔达微电池有限责任公司

Dates

Publication Date
20260508
Application Date
20240807
Priority Date
20230808

Claims (9)

  1. 1. An energy storage element (100) having the following features: a. The energy storage element includes an electrode-separator assembly (104) having an anode (105)/separator (156)/cathode (108) in a sequential arrangement, B. The electrode-separator assembly (104) is in the form of a cylindrical wound member having a first end face (104 a) and a second end face (104 b) and a wound member housing (104 c) therebetween, C. The anode (105) of the electrode-separator assembly (104) comprises an anode current collector (106) having a first longitudinal edge (106 a) and a second longitudinal edge parallel to the first longitudinal edge, a main region loaded with a layer of negative electrode material (107), and a free edge strip extending along its first longitudinal edge (106 a) and not loaded with the negative electrode material, D. The cathode (108) of the electrode-separator assembly (104) comprises a cathode current collector (109) having a first longitudinal edge (109 a) and a second longitudinal edge parallel to the first longitudinal edge, a main region loaded with a layer of positive electrode material (110), and a free edge strip extending along its first longitudinal edge (109 a) and not loaded with the positive electrode material, E. the anode (105) and the cathode (108) are arranged within the electrode-separator assembly (104) in such a way that a first longitudinal edge (106 a) of the anode current collector (106) protrudes from the first end face (104 a) and a first longitudinal edge (109 a) of the cathode current collector (109) protrudes from the second end face (104 b) of the electrode-separator assembly (104), F. The energy storage element comprises a contact sheet metal member (112) resting on a first longitudinal edge (106 a) of the anode current collector (106) and covering the first end face (104 a), or resting on a first longitudinal edge (109 a) of the cathode current collector (109) and covering the second end face (104 b) and being connected to the second end face, G. The energy storage element comprises a gas-and liquid-tight closed housing comprising a metal housing cup (101) with a terminal circular opening and a cover (102) with a circular rim (102 a), which closes the circular opening and encloses an interior space, in which the electrode-membrane assembly (104) is arranged, H. The cover (102) comprises a metal disc (113) with a circular edge, wherein the metal disc (113) has an inner side defining the inner space, It is characterized in that the method comprises the steps of, I. The contact sheet metal member (112) comprises a distance compensation region (112 d) connected with the inner side of the metal disc (113) in a connection region (112 e), or a distance compensation sheet metal member (177) is welded to the contact sheet metal member (112), the distance compensation sheet metal member (177) comprising a distance compensation region (177 a) connected with the inner side of the metal disc (113).
  2. 2. The energy storage element (100) of claim 1, having at least one of the following additional features: a. The cover (102) is a cover assembly comprising, in addition to the metal disc (113), an electrode cap (117) in electrical contact with the metal disc (113), B. The electrode cap (117) rests directly on the metal plate (113), C. the electrode cap (117) and the metal plate (113) enclose an intermediate space, D. The metal plate (113) comprises a connection region (113 a) in which a connection is made to the connection region (112 e) or the connection region (177 b), E. the electrode cap (117) comprises at least one perforation (117 a) through which the connection region (113 a) is accessible from outside the housing, in particular from outside the housing, which is accessible by laser light.
  3. 3. The energy storage element (100) of claim 1 or claim 2, having at least one of the following additional features: a. The contact sheet metal component (112) comprises a contact region (112 c), in particular a disk-shaped contact region, to which the longitudinal edge (106 a) of the anode current collector (106) or the longitudinal edge (109 a) of the cathode current collector (109) is welded or connected via a material-locking connection or a form-locking connection, B. The contact region (112 c) encloses the distance compensation region (112 d) which extends from the plane of the contact region (112 c) to the metal disk (113).
  4. 4. The energy storage element (100) of claim 1 or claim 2, having at least one of the following additional features: a. The distance compensating sheet metal component (177) comprises a contact region (177 c), in particular an annular disk-shaped contact region (177 c), which is connected to the contact sheet metal component (112) by welding or by means of an alternative material-locking connection or form-locking connection, B. The contact region (177 c) encloses the distance compensation region (177 a) extending from the plane of the contact region (177 c) to the metal plate (113).
  5. 5. The energy storage element (100) according to any of the preceding claims, having at least one of the following additional features: a. The metal disc (113) is formed as a PRV (pressure relief valve) and comprises for this purpose an elongated weakening groove (199), B. In the connection region (113 a), the metal disk (113) is characterized by a lower material thickness than in the region surrounding the connection region (113 a).
  6. 6. The energy storage element (100) according to any of the preceding claims, having at least one of the following additional features: a. The housing comprises a seal (103) made of plastic material, which surrounds the rim (102 a) of the cover (102) and is arranged between the cover (102) and the housing cup (101), B. The energy storage element comprises a support ring (189) made of plastic material, which is arranged, in particular clamped, between the metal disc (113) and the distance compensating sheet metal member (177) or between the metal disc (113) and the contact sheet metal member (112), C. the support ring (189) rests on a contact area (112 c) of the contact sheet metal member (112) or on the contact area (177 c) of the spacing compensating sheet metal member (177), D. the support ring (189) is part of the seal (103).
  7. 7. The energy storage element (100) according to at least one of the preceding claims, having at least one of the following additional features: a. The housing cup (101) comprises, in axial order, a bottom (101 a), a central section (101 b) and a closing section (101 c), wherein, -The central section (101 b) is cylindrical in shape, and in the central section (101 b) a winding housing (104 c) of the electrode-separator assembly (104), which is designed as a winding, is in contact with the inside of the housing cup (101), and -In the closing section (101 c), the annular seal (103) is in pressing contact with the edge of the lid (102) and the inside of the housing cup (101), and B. The housing cup (101) has an opening edge (101 d) in the closing section (101 c) defining the circular opening, which is bent radially inwards on the edge of the cover (102) enclosed by the seal (103), and which secures the cover (102) comprising the seal (103) in the circular opening of the housing cup (101) in a form-locking manner.
  8. 8. A cap assembly (102) having the following features: a. The cap assembly includes a metal plate (113) and an electrode cap (117) in electrical and direct mechanical contact with each other, B. The electrode cap (117) rests directly on the metal plate (113), C. the electrode cap (117) and the metal plate (113) enclose an intermediate space, D. The electrode cap (117) comprises at least one perforation (117 a) through which the connection region (113 a) is accessible from outside the housing, in particular laser light is accessible from outside the housing, E. the cap assembly includes a seal (103) fitted over an edge thereof.
  9. 9. A method of manufacturing an energy storage element (100) according to any one of claims 1 to 7, comprising the steps of: a. Providing a metal shell cup (101) having a circular end opening, B. Providing an electrode-separator assembly (104) having an anode (105)/separator (156)/cathode (108) in a sequential arrangement, the electrode-separator assembly having a first end face (104 a) and a second end face (104 b), C. a contact sheet metal member (112) is applied to one of the end faces, D. If desired, welding a distance compensating sheet metal member (177) to the contact sheet metal member or securing the distance compensating sheet metal member (177) to the contact sheet metal member by forming an alternative material locking connection or form locking connection, E. Inserting the electrode-membrane assembly (104) into the housing cup (101), F. The circular opening of the housing cup (101) is closed by means of a cover (102), G. A connection, in particular a welded connection, is established between the cover (102) and the contact sheet metal member (112) or between the cover (102) and the distance compensating sheet metal member (177).

Description

Energy storage element, cover assembly and manufacturing method Technical Field The described invention relates to an energy storage element, a cover assembly, and a method of manufacture. Background The electrochemical energy storage element may convert stored chemical energy into electrical energy via a redox reaction. The simplest form of electrochemical energy storage element is an electrochemical cell. The electrochemical cell includes a positive electrode and a negative electrode with a separator disposed therebetween. During discharge, electrons are released at the negative electrode due to the oxidation process. This produces an electron current that can be drawn by an external electrical consumer for which the electrochemical cell serves as an energy source. At the same time, an ion current corresponding to the electrode reaction occurs in the battery cell. This ionic current passes through the membrane and is achieved by the ion conducting electrolyte. Thus, the separator prevents direct contact between the electrodes. At the same time, however, it enables charge balance between the electrodes. If the discharge is reversible, that is, if the conversion of chemical energy to electrical energy that occurs during the discharge can be reversed and the battery cell recharged, the battery cell is referred to as a secondary battery cell. In a secondary battery cell, a negative electrode is generally designated as an anode and a positive electrode is designated as a cathode, which refers to the discharge function of an electrochemical cell. Secondary lithium ion battery cells are used as energy storage elements in many applications today because they can provide high currents and have relatively high energy densities. Secondary lithium ion cells are based on the use of lithium, which can migrate back and forth between the electrodes of the cell in the form of ions. The negative and positive electrodes of lithium ion cells are typically formed from so-called composite electrodes that include electrochemically inactive components in addition to electrochemically active components. In principle, any material that can absorb lithium ions and release lithium ions again can be used as an electrochemically active component (active material) for the secondary lithium ion battery cell. For the negative electrode, carbon-based particles (e.g., graphitic carbon) are used for this purpose. Active materials for the positive electrode may include lithium cobalt oxide (LiCoO 2), lithium manganese oxide (LiMn 2O4), lithium iron phosphate (LiFePO 4), or derivatives thereof. The electrochemically active material is typically contained in the electrode in particulate form. As electrochemically inactive components, composite electrodes typically comprise flat and/or ribbon-shaped current collectors (e.g., metal foils) that serve as carriers for the respective active materials. The current collectors are typically coated with a thin layer of the corresponding active material. The current collector for the negative electrode (anode current collector) may be made of, for example, copper or nickel, and the current collector for the positive electrode (cathode current collector) may be made of, for example, aluminum. In addition, as electrochemically inactive components, the electrode may include an electrode binder (e.g., polyvinylidene fluoride (PVDF) or other polymers, such as carboxymethyl cellulose), conductivity enhancing additives, and other additives. The electrode binder ensures mechanical stability of the electrode and also generally ensures adhesion of the active material to the current collector. As an electrolyte, lithium ion battery cells typically include a solution of a lithium salt, such as lithium hexafluorophosphate (LiPF 6), in an organic solvent, such as ethers and esters of carbonic acid. During the manufacture of lithium ion battery cells, the composite electrode is typically combined with one or more separators to form an electrode-separator assembly. The electrode and the separator are typically (but not necessarily) connected to each other under pressure, but may also be connected to each other by lamination or gluing. The basic function of the battery cell may then be established by impregnating the assembly with electrolyte. In many embodiments, the electrode-separator assembly is formed in the form of a wound piece or is machined into a wound piece. In the first case, for example, the strip-shaped positive electrode and the strip-shaped negative electrode and at least one strip-shaped separator are fed individually to a winder and wound into a wound piece in a spiral order of positive electrode/separator/negative electrode. In the second case, the strip-shaped positive electrode and the strip-shaped negative electrode and the at least one strip-shaped separator are first connected to form an electrode-separator assembly, for example by applying the aforementioned pressure. In a further step, the assem