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
  • H01M50/572—Means for preventing undesired use or discharge
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/02—Details
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/05—Accumulators with non-aqueous electrolyte
  • H01M10/052—Li-accumulators
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/05—Accumulators with non-aqueous electrolyte
  • H01M10/052—Li-accumulators
  • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/60—Heating or cooling; Temperature control
  • H01M10/65—Means for temperature control structurally associated with the cells
  • H01M10/655—Solid structures for heat exchange or heat conduction
• • 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
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/116—Primary casings; Jackets or wrappings characterised by the material
  • H01M50/117—Inorganic material
  • H01M50/119—Metals
• • 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
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/116—Primary casings; Jackets or wrappings characterised by the material
  • H01M50/121—Organic material
• • 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
  • H01M50/10—Primary casings; Jackets or wrappings
  • H01M50/116—Primary casings; Jackets or wrappings characterised by the material
  • H01M50/124—Primary casings; Jackets or wrappings characterised by the material having a layered structure
• • 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
  • H01M50/572—Means for preventing undesired use or discharge
  • H01M50/574—Devices or arrangements for the interruption of current
  • H01M50/581—Devices or arrangements for the interruption of current in response to temperature
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/10—Energy storage using batteries

Definitions

• the present invention relates to a rechargeable galvanic cell having at least one lithium-intercalating electrode and a sealed, thin and flexible housing which is protected against damage caused by short-circuiting or overcharging.
• rechargeable lithium-ion cells are preferably used as energy sources in portable devices such as portable MP3 players, PDAs, organizers, notebooks or telephones.
• lithium-ion cells or lithium polymer cells have combustible constituents, for example an electrolyte based on organic carbonates. In combination with the high energy density of such cells, this represents a potential hazard for the consumer. Accordingly, special safety precautions must be taken in order to exclude risks for the consumer or to minimize them as far as possible.
• Lithium-ion cells or lithium-polymer cells can be damaged in particular by power surges, such as those caused by an external short circuit, or by overcharging and may even catch fire or explode. Statistically, overloading is one of the most common causes of cell defects.
• Lithium-ion cells in particular lithium-polymer cells, a graphite-containing anode and a lithium-cobalt-oxide-based cathode are particularly common.
• a graphite-containing anode and a lithium-cobalt-oxide-based cathode are particularly common.
• lithium ions from the Lithium cobalt oxide outsourced and intercalated into the graphite layers of the anode If such a cell is overloaded, in particular to a voltage of more than 4.2 V 1, then it happens that more lithium ions are removed than can be absorbed by the graphite layers of the anode. As a result, superficially highly reactive metallic lithium deposits on the anode.
• lithium-ion cells especially lithium-polymer cells
• safety electronics that monitor the charging and discharging process and protect the cell from improper handling, especially from external short circuits.
• electronic fuses have the disadvantage that they are relatively expensive and under extreme conditions such as e.g. high temperatures in sunlight can fail. Rather, therefore, cells are required which can withstand external short circuits or overloads even in the absence of safety electronics.
• the present invention provides a galvanic cell having the features of claim 1 that meets these requirements.
• Preferred embodiments of the galvanic cell according to the invention are specified in the dependent claims 2 to 7. The wording of all claims is hereby incorporated by reference into the content of this specification.
• a rechargeable galvanic cell according to the present invention has at least one lithium-intercalating electrode.
• the galvanic cell according to the invention is therefore preferably a lithium-ion cell, in particular a lithium-polymer cell.
• the galvanic cell according to the invention has a housing made of two films, which are sealingly connected to each other via an adhesive or sealing layer, so that substantially no moisture from the outside can penetrate into the housing and liquid electrolyte optionally contained in the housing can not escape.
• the housing films are particularly preferably aluminum composite films, in particular having the sequence polyamide / aluminum / polypropylene.
• the housing films generally have a maximum thickness of 160 microns, so that a very thin and flexible housing results.
• a galvanic cell according to the invention is characterized in that it has at least one current conductor in which at least one irreversibly triggering thermal fuse is integrated.
• the tripping is used in the case of the galvanic cell according to the invention
• So fuse is not caused by the current flowing through it, but rather exclusively by its temperature.
• a cell according to the invention is overloaded, then the irreversibly triggering thermal fuse is activated by the heat generated during the overcharging and opens the circuit - likewise irreversibly. Further overcharging is then no longer possible, and already damaged cells - in contrast to reversible security elements - can not be overloaded again. In the case of reversible fuses, on the contrary, there is the danger that the cell - A - is recharged after cooling and after several shutdown cycles. Point is reached at which the above-mentioned explosive combustion begins.
• the at least one fuse is preferably arranged inside the housing, but may alternatively or additionally be embedded in the adhesive or sealing layer.
• the fuse When the fuse is located within the housing, it may be preferred that it be provided with a plastic coating resistant to organic electrolytes.
• a plastic coating resistant to organic electrolytes for example, adhesive tapes or films based on polyimides, polyethylene, polypropylene, epoxy resin or polyurethane come into question.
• the term "embedded” should be understood to mean that the thermal fuse is essentially completely surrounded by the housing films and thus can not come into direct contact either with electrolyte which may be contained in the housing or with the environment outside the housing the arrangement of the thermal fuse within the adhesive or sealing layer has the advantage that within the housing no space is lost, which could be used for active materials.
• the thermal fuse to a nominal operating temperature of 90 0 C and 100 0 C. Furthermore, it is preferred that the thermal fuse has a holding temperature between 50 0 C and 60 0 C. The aforementioned values were determined in each case at a rated current of 2 A.
• the rated trip temperature is the temperature at which the thermal fuse changes its conductivity and the current circle opens.
• the holding temperature is the maximum temperature at which the rated current flows through the thermal fuse for a given time (in the present case 100 hours) without the fuse tripping, ie the conductivity changes and the circuit opens.
• the thermal fuse has a maximum temperature limit of 150 0 C.
• the maximum temperature limit is understood to be the temperature at which the thermal fuse retains its mechanical and electrical properties after tripping and above which current can flow again.
• the internal resistance of a galvanic cell according to the invention is preferably in the range between 20 mOhm and 100 mOhm.
• the thermal fuse is particularly preferably a fuse based on an alloy, in particular based on Roses metal and / or d'Arcets metal.
• Roses Metal is known to be an alloy of bismuth, lead and tin. The melting point of this alloy is about 98 0 C, and thus below the boiling point of water.
• Roses Metall consists of 50% bismuth, between 25 and 28% lead and between 22 and 25% tin and has a density of about 9.32 g / cm 3 . The same applies to d'Arcet's metal, also an alloy of bismuth, tin and lead, but this has a slightly lower melting point of about 93.75 0 C.
• the housing films of a galvanic cell according to the invention are, in particular, metal / plastic composite films such as the aluminum composite film already mentioned above. It is particularly preferred that these composite films have a metal layer which, on its side facing the housing interior, is provided with an electrical insulation. tor, for example, an insulating plastic film or an insulating tape coated.
• the metal is preferably copper, aluminum or an alloy of these metals.
• a further layer, in particular a thin plastic layer, for example made of a polyester, can be arranged.
• the insulating layer on the inside of the housing facing side of the metal layer has a thickness between 20 microns and 70 microns. It has been found that it is ensured within this range that the thermal fuse of a galvanic element according to the invention responds very quickly. In the case of an overcharge or a short circuit, the heat propagates starting from the electrodes of the galvanic cell according to the invention, inter alia, namely via the housing films of a galvanic cell according to the invention. However, the transmission of heat to the thermal fuse can be carried out relatively slowly, if the insulating layer has too large a thickness.
• the insulating layer is a polyolefin layer, e.g. a layer of polypropylene as in the aluminum composite film mentioned above.
• the two housing films can be connected to one another by adhesive bonding or else by other customary measures, for example by welding and / or heat sealing. Suitable measures are known to the person skilled in the art.
• a galvanic cell according to the invention has at least one galvanic single element with two electrodes arranged in a stack.
• a separator is always arranged between the electrodes, so that the at least one galvanic individual element usually comprises a succession of negative electrode / separator / positive electrode.
• the at least one positive electrode can have, for example, lithium cobalt oxide as the active material.
• the at least one negative electrode comes as an active material, for example graphite in question.
• the separator is usually made of a preferably porous plastic, for example a polyolefin.
• the galvanic cell according to the invention may of course also comprise an electrolyte, for example an organic electrolyte based on carbonate, as already mentioned above.
• Fig. 1 shows schematically the basic structure of a cell according to the invention with integrated thermal fuse.
• FIG. 2 shows the behavior of a cell according to the invention in the case of overcharging.
• Fig. 3 shows the behavior of a comparative cell without irreversible thermal fuse.
• an irreversibly triggering thermal fuse element 3 is integrated in one of the arresters 2 of the cell 1, which is made, for example, of nickel, copper or aluminum. welded.
• the fuse element 3 is arranged so that it is arranged in the sealing layer 4 of the cell. When the housing is closed, the securing element 3 is essentially completely encased by the housing films.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Inorganic Chemistry (AREA)
• Materials Engineering (AREA)
• Connection Of Batteries Or Terminals (AREA)
• Secondary Cells (AREA)
• Sealing Battery Cases Or Jackets (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (7)

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• 2008
  • 2008-04-17 DE DE102008020912A patent/DE102008020912A1/de not_active Ceased
• 2009
  • 2009-04-15 JP JP2011504369A patent/JP2011519124A/ja active Pending
  • 2009-04-15 CN CN2009801140904A patent/CN102027620A/zh active Pending
  • 2009-04-15 WO PCT/EP2009/002740 patent/WO2009127396A1/de active Application Filing
  • 2009-04-15 EP EP09733055A patent/EP2297803A1/de not_active Withdrawn
  • 2009-04-15 US US12/937,558 patent/US20110086253A1/en not_active Abandoned
  • 2009-04-15 KR KR1020107022797A patent/KR20110009108A/ko not_active Application Discontinuation

Non-Patent Citations (1)

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