Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/50—Current conducting connections for cells or batteries
  • H01M50/531—Electrode connections inside a battery casing
  • H01M50/536—Electrode connections inside a battery casing characterised by the method of fixing the leads to the electrodes, e.g. by welding
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/50—Current conducting connections for cells or batteries
  • H01M50/531—Electrode connections inside a battery casing
  • H01M50/538—Connection of several leads or tabs of wound or folded electrode stacks
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M6/00—Primary cells; Manufacture thereof
  • H01M6/04—Cells with aqueous electrolyte
  • H01M6/06—Dry cells, i.e. cells wherein the electrolyte is rendered non-fluid
  • H01M6/10—Dry cells, i.e. cells wherein the electrolyte is rendered non-fluid with wound or folded electrodes

Definitions

• the present invention relates to a method of provi ⁇ ding an electrical connection in a sealed battery cell be- tween an electrode and an electrically conducting end mem ⁇ ber of the cell container.
• the invention also relates to a battery cell manufactured in this way.
• Technical Background At the manufacture of battery cells it is of great importance to accomplish the electrical connection between the internal electrodes of the cell and the externally accessible contact portions of the cell container, i e nor ⁇ mally the bottom and the end cover, in the cheapest pos ⁇ sible way and with asserted functional security.
• a typical example of a prior technique for this pur ⁇ pose is shown in FR-A-2 356 284.
• one of the electro ⁇ des in a battery coil directly contacts the cylindrical side wall of the metallic cell container, whereas the other electrode has protruding end edges, which downwardly rest against an electrically isolating bottom plate in the cell container and which upwardly directly or under assistance of contact plates contact the cover of the cell container.
• the uppwardly extending end edges can hereby be soldered to the cover or the contact plate .
• the method according to the invention is characterized in that an electrically conducting net edge is left at the application of electrode material on an electrode net for the production of a plate shaped electrode, that the electrode - together with another electrode and separators - is wound into a battery coil with the net edge protruding from one end, that the battery coil is placed in the cell container with the net edge in contact with the end member, and that a welding joint between the end member and the net edge is externally accomplished.
• line shaped welding joints are accomp ⁇ lished by laser welding, but any other conventional welding technique may also be utilized. Two such parallel welding joints can be accomplished.
• the welding joints can preferably be concurrently accomplished in the two ends .
• Electrolyte shall preferably be poured into the battery cell only after an accomplished welding operation, which is possible if the upper end cover has a center hole for a safety valve, which is mounted later.
• the invention also relates to a battery cell manufac ⁇ tured in the above mentioned way. This battery cell can have the characteristics defined in claims 5 - 8.
• Fig 1 in a side view shows the different components of a battery coil before winding
• Figs 2 and 3 in a side view and a top view, respectively, show a wound battery coil
• Fig 4 is a side view of a battery coil after formation
• Figs 5 - 7 in a longitudinal section
• a top view and a bottom view respectively, show a battery cell after a wel ⁇ ding operation
• Figs 8 and 9 are enlargements of the upper and lower portions, respectively, of Fig 5.
• the starting material for an electrode coil for a battery cell comprises, - as is shown in Fig 1 - a negative, plate shaped electrode 1, a separator 2, a positive, plate shaped electrode 3 and again a separator 2.
• the posi ⁇ tive electrode contains nickel material and the negative electrode a metal hydride.
• the electrode material for the respective electrodes is rolled or pressed onto a metal thread net.
• the total widths or heights in Fig 1 of the electrodes proper can be about 45 mm whereas the respective net edge can have a width of 1.5 mm.
• the electrode nets with the net edges can be manufactu ⁇ red of electrically conducting thread with a diameter of about 0.2 mm. For obtaining a good mechanical stability the net edges 1' and 3' can be folded against themselves.
• a battery coil 4 with an appearance according to Figs 2 and 3 will be formed, where the lower lug formed by the net edge 1' forms part of the negative electrode and the upper lug formed by the net edge 3 ' forms part of the positive electrode.
• a central, axial hole through the battery coil 4 is formed, as most clearly appears in Fig 3.
• the diameter of the coil can be about 12.5 mm and the diameter of the hole 3 mm.
• the battery coil thus modified has the reference numeral 4A.
• This modified battery coil 4A is arranged in a battery cell container, which is most clearly shown in Fig 5 and which consists of a mainly cylindrical tube 5 with two discs 6 and 7 closing the two ends.
• This battery con ⁇ tainer 5 - 7 is described in more detail in the internatio ⁇ nal patent application PCT/SE95/01064 from the same appli- cant; reference is made to this application, but the fol ⁇ lowing short description can be made in this context:
• the cylindrical tube 5 is manufactured of a thermo ⁇ plastic material, whereas the circular discs or covers 6 and 7 are manufactured of an electrically conducting plate material and are so melted or pressed into the tube 5 that a pressure tight sealing is accomplished.
• the upper cover 7 can be provided with a safety valve, which is described in the patent application mentioned above and in Figs 5 and 8 appears as a central hole.
• the outer diameter of the tube 5 can be 14 mm and its length 50.5 mm.
• the latter may already be provided with the bottom cover 6 and be upwardly open.
• the top cover 7 is placed or pressed in position and is attached by melting, so that a battery cell container 5 - 7, which is closed with the ex ⁇ ception of the safety valve, is accomplished.
• This comple ⁇ ted container can have a length of about 49 mm. Due to the oblique formation of the ends of the battery coil 4 descri ⁇ bed above in connection with Fig 4 the battery coil will fill the cell container 5 - 7 well, so that a best possible capacity utilization is obtained.
• a preferably line shape welding is made externally at the covers 6 and 7, so that the net lugs 1' and 3' are melted to the respective covers 6 and 7.
• Figs 5 - 9 two such line shaped welding joints 8 are shown. The welding operations are preferably concurrently performed at the two ends of the battery cell.
• the welding is preferably performed with laser tech ⁇ nique, but other well known welding techniques are also possible.
• the cover material is in principle melted in lines, whereas the underlying net mate- rial is heated, so that the materials of the cover and the net are melted together in an electrically conducting and mechanically strong joint.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Connection Of Batteries Or Terminals (AREA)
• Primary Cells (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=20400191

Family Applications (1)

Country Status (4)

Families Citing this family (4)

Family Cites Families (3)

• 1995
  • 1995-11-14 SE SE9504022A patent/SE9504022L/xx not_active Application Discontinuation
• 1996
  • 1996-11-12 WO PCT/SE1996/001453 patent/WO1997018594A1/en not_active Ceased
  • 1996-11-12 EP EP96939405A patent/EP0871982A1/de not_active Withdrawn
  • 1996-11-12 AU AU76595/96A patent/AU7659596A/en not_active Abandoned

Non-Patent Citations (1)

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