CA2345319C - Composite electrode including ptc polymer - Google Patents
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- CA2345319C CA2345319C CA002345319A CA2345319A CA2345319C CA 2345319 C CA2345319 C CA 2345319C CA 002345319 A CA002345319 A CA 002345319A CA 2345319 A CA2345319 A CA 2345319A CA 2345319 C CA2345319 C CA 2345319C
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/64—Carriers or collectors
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- 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
- H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
- H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
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- 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
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- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/64—Carriers or collectors
- H01M4/66—Selection of materials
- H01M4/665—Composites
- H01M4/667—Composites in the form of layers, e.g. coatings
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- H—ELECTRICITY
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- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2200/00—Safety devices for primary or secondary batteries
- H01M2200/10—Temperature sensitive devices
- H01M2200/106—PTC
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/134—Electrodes based on metals, Si or alloys
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/64—Carriers or collectors
- H01M4/66—Selection of materials
- H01M4/668—Composites of electroconductive material and synthetic resins
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- H—ELECTRICITY
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- 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
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/46—Separators, membranes or diaphragms characterised by their combination with electrodes
- H01M50/461—Separators, membranes or diaphragms characterised by their combination with electrodes with adhesive layers between electrodes and separators
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- 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
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- 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
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- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
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- Y02E60/10—Energy storage using batteries
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Abstract
A composite electrode (18) for a rechargeable lithium battery is described. The composite electrode has a metallic current collector (12) in contact with an electrically conducting organic polymer laminate (14) made of a blended and annealed polymeric mixture containing fine carbon particles, and coated with an electrode-active substance bearing layer (16). The conducting polymer is capable of reversible resistivity changes of several orders of magnitude in only a portion of the laminate, thereby reducing locally excessive current flow and over-heating in the rechargeable lithium battery.
Description
COMPOSITE ELECTRODE INCLUDING PTC POLYMER
FIELD OF INVBHTION
This invention is related to lithium batteries, in particular to current collectors utilized in rechargeable lithium batteries and electrochemical cells.
HaCKGROUND OF THE INV~iTION
Lithium batteries are often utilized in systems where high energy density per volume or weight is desirable.
Lithium batteries or cells may be button shaped, cylindrically or prismatically wound, or flat, composed of layers, known as planar cells or planar batteries. In most instances lithium based electrochemical cells are rechargeable, or are referred to as secondary batteries. Lithium electrochemical cells or batteries include a negative electrode or anode, containing a substance capable of intercalating lithium, or lithium metal or an alloy of lithium, as the negative active component. Th~
positive active component in the cathode is usually a chalcogenide of a transition metal and lithium, such as lithium-manganese oxide, lithium-cobalt oxide and similar type of compounds. The non-aqueous electrolyte may be a porous separator impregnated with an organic liquid containing a dissolved lithium salt, or a solid polymer containing a dissociable lithium compound, or composed of particles of solid polymer containing dissociable lithium compounds which particles are intermixed with one of the electrode active compound containing particles. Lithium batteries are usually equipped with current collectors in close proximity of the electrodes, which can be a metallic plate, rod, grating or foil, most frequently made of copper or aluminum, or similar metals or alloys thereof. The packaging of thin plate lithium cells often utilize metallic foils carried by a polymeric laminate, in addition to other polymeric layers designed to protect the rechargeable lithium battery from corrosion and mechanical damage. It is noted that.the packaging polymeric laminate carrying metallic foil is an insulator and is usually impermeable to liquids and gases. The lithium batteries under consideration may be composed of a single rechargeable lithium SUBSTITUTE SHEET (RULE 26) electrochemical cell or several rechargeable lithium cells stacked, folded or interconnected in a known manner to make up a lithium battery.
It is of importance that good contact is maintained between the current collector and the respective electrode so that the energy the lithium battery is capable of delivering is maximized under normal conditions. There are known methods to improve electrical contact between the cell electrode and the internal surface of the current collector.
One of such methods is designed to eliminate or reduce oxide formation on the surface of the metallic current collector.
In another method a conductive polymeric layer is inserted between the cuzrent collector and the electrode. Hy way of examples, a !ew patents which are directed to conductive polymeric layers, are discussed below. U.S.patent 5,262,254 issued to Koksbang et al. teaches an electronically conductive polymeric layer which can protect the metallic collector from attack by the cell electrolyte. U.S.patents 5,441,830 and 5,464,707, issued to Moulton et al. on August 15, 1995 and Movember 7, 1995, respectively, discuss adhesion-promoting polymeric mixtures bearing fine carbon powder, which are coated on a metallic foil, or on a metallic layer supported by a polymer laminate, and then cured or dried. The electrode paste is deposited on the cured or dried adhesion promoting coating. U.S.patents 5,464,706 and 5,547,782, issued to Dasgupta et al. on November 7, 1995 and August 20, 1995, respectively, disclose conductive polymeric layers loaded with ceramic or carbon particles of certain particle size range, inserted to be in contact with the electrode and the metallic collector surface, with the objective to diminish corrosion.
' U.S.patent 5,554,459, issued to Gozdz et al. on September 10, 199fi, teaches cleaned collector elements, more specifically a metallic grid, coated with an adherent, carbon loaded, electrically conductive polymer composition. U.S.patent 5,728,181, issued to Jung et nl. on March 17, 1998, discloses a conductive ink composed of.a long chained polymer and tine carbon coated on n current collector surface, onto which nn electrode layer is subsequently deposited, and the two layers SUBSTITUTE SHEET (RULE 2fi) carried by the current collector are then bonded together by radiation or heat curing. However, the resistivity of the above discussed conductive polymeric layers is likely to change with temperature gradually, and temperature induced structural changes within the solid polymeric layers are not known to be reversible. -High temperatures within the battery may be caused by too high overall currents during charging or discharging, or it can arise in the course of normal battery operation, brought about by local irregularities in the interaction between the cell components. Moreover, localized short circuits can lead to high currents within only a small portion of the cell, thereby creating a notable increase of temperature in the neighbourhood of the trouble area or a hat spot in the battery. The locally high temperature can damage the electrolyte or reduce the porosity of the separator, thereby blocking irreversibly the passage of ions, generate harmful gases which may ultimately lead to explosion and fire, or otherwise affect the safe operation of the battery. If some means can be found to diminish the high local current and thus reduce the high local temperature, the battery may be able to continue to operate nonaally. It is noted that there are several known methods whereby externally installed fuses or switches can stop the battery charging or discharging process , should the current rise beyond a permitted level. Some such fuses are known to operate reversibly. However, such fuses are located in a circuit external of the battery, or are installed in series with the cells, and respond only to the total current drawn through the battery or the cell.
There are known electrically conducting, carbon bearing, blended polymeric compositions, which are capable of exhibiting resistivity changes amounting to several orders of magnitude in a reversible manner in a pre-selected, relatively narrow temperature range. Such compositions are taught, for example, in U.S.patent 3,793,716, issued to R. Smith-Johannsen on February 26, 1974, and in U.S. patent 4,237,441, issued to P. van Konynenburg et al. on December 2, 1980. Compositions of such type are utilized in self-limiting electrical heating SUBSTITUTE SHEET (RULE 26) elements, in heat activated switches comprising electrodes separated by a polymer having positive heat coefficient, in reversible fuses, and in similar devices. A particular application of conductive polymers is described in U.S.patent 4,957,612, issued to R.F.Stewart et al. on Sept.l8, 1990, wherein a metallic core of an electrode is coated witri~an electrically conductive polymer,, which carries another conductive and electrochemically active component bearing polymer. The resistivities~ of the conductive polymers are different relative to one another at a given temperature.
There is a need for a thin conductive layer for insertion between the current collector and the electro-active layer in a rechargeable lithium battery, which is capable of reversible resistivity change of several orders of magnitude in response to locally high current flow and attendant local overheating within the battery, thereby being able to render protection from explosion and combustion.
SU1~1ARY OF THE INVENTION
An improved rechargeable lithium battery has been devised wherein an organic polymer laminate rendered electrically conductive by embedded electrically conductive particles, is forming a composite electrode in conjunction with an electrode layer containing an electrode-active substance, and a current collector. The electrically conductive organic polymer laminate has a thickness and faces which are in contact with the electrode layer and the current collector, respectively.
The electrically conductive organic polymer laminate has a positive temperature coefficient of resistivity, a resistivity switch temperature Tn, between 75 and 120°C, and the organic polymer laminate is capable of reversible resistivity change of at least 2 orders of magnitude within a 5° temperature band of the resistivity switch temperature T~., in a portion of the total volume of the electrically conductive organic polymer laminate. The electrically conductive particles embedded in the organic polymer laminate are very fine carbon particles or carbon black having particle size less than 0.1 Vim.
In another embodiment the composite electrode including an electrically conductive organic polymer laminate, carries SUBSTITUTE SHEET (RULE 26) a lithium ion containing adhesive layer on the face adjacent the electrolyte in the rechargeable lithium battery.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig.la and lb are schematic drawings of the cross-section of the composite electrode, and of a rechargeable lithium battery incorporating composite~electrodes of the present invention.
The preferred embodiments of the invention with reference to the drawings and working examples will now be described.
DETAILED DISCiISSION OF THE PREFERRED EtH30DIMEHTS
For the sake of clarity, the meaning of some of the expressions in the present discussion, as they are understood, will be given below:
An electrically conductive organic polymer is one wherein the charge carriers are electrons.
Positive temperature coefficient of resistivity is understood to mean that the resistivity, measured in ohm.cm, of the polymeric laminates under consideration in this discussion, increases with temperature. The tangent drawn to the values of resistivity of a solid plotted against temperature, gives the temperature coefficient of resistivity.
Resistivity switch temperature Tr~: the composition of the polymer laminates utilized in the present invention affects the nature of the electronic path and electronic mobility within the organic polymer laminate, such that the resistivity undergoes a rapid and substantial change around a given temperature. Below the resistivity switch temperature T~, the value of the resistivity in the polymer composition is a fraction of the resistivity above that temperature. The resistivity change with temperature is reversible.
As mentioned above, there are known polymer compositions having electrically conductive carbon particles dispersed therein, which are capable of undergoing a rapid and reversible change in resistivity with temperature. The type and mixture of polymers, the size and surface area of the carbon particles, the manner the particles are mixed with the polymers and the subsequent heat treatment , al l have an ef f ect on the value of the resistivity, and on the magnitude and SUBSTITUTE SHEET (RULE 26) temperature of the resistivity switch. It is noted that no invention per se, is claimed for the polymer compositions utilized in the improved rechargeable lithium battery of this invention. Most of the known carbon containing polymer compositions which have positive temperature coefficient of resistivity and are capable resistivity switch, utilize carbon particles of size less than 100 millimicron (m~) or O.l~m.
It has also been briefly discussed that the usual fields of utilization of organic polymer compositions having positive temperature coefficient of resistivity, are heater tapes, heat sensitive electric switches, heat sensitive fuses and electrical devices of similar nature. In such devices, it is of importance that substantially the entire surface of the polymer making the desired contact within the device is close to the same temperature, that is the volume corresponding to the operative surface of the electrically conductive polymer has substantially similar values of resistivity.
It has now been found that when known polymer compositions capable of undergoing crystallinity changes between 70 and 120'C, are loaded with carbon black or similar very fine carbon, of particle size less than 0.1 um, in concentrations less than 15 vol.%, blended, then heat treated or annealed in a known manner and laminated to sheets of less than 50um thick, then portions of the electrically conductive laminate obtained are capable of responding to local changes of temperature. if a portion of the laminate is at a temperature T1, which is different from the temperature Tz of the rest of laminate, then the resistivity of the laminate portion at T1 will be different from the resistivity of the laminate portion at temperature TZ. When T1 and TZ fall in the temperature range the polymer composition of the laminate is undergoing a reversible crystallinity change, that is close to the resistivity switch temperature Tr" then one portion of the electrically conductive polymer laminate can have a resistivity value which is several orders of magnitude different from the resistivity of the other portion. In other words, if a relatively small volume of the polymer laminate of such composition is heated to above its T=" the SUBSTITUTE SHEET (RULE 26) _ 7 resistivity of this volume will increase very significantly, and when the temperature drops below the temperature referred to as Tr" the lower resistivity is restored. It is believed, however, this reasoning is not considered binding, that the very small, less than O.l~Cm size of the carbon particles allows rapid rearrangement within the polymer laminate structure with temperature, thereby altering the path of the electronic charge carriers, which then results in substantial change in the resistivity of the polymer laminate. The crystallinity changes discussed above are the characteristic of certain polymer blend types, and are understood to be changes within a solid state taking place well below the melting temperature of the blend. Structural changes which are brought about by melting the polymeric mixture are excluded from the above considerations.
Rechargeable lithium batteries normally operate at temperatures below 70C. If during discharging or charging, the current in the battery goes above the level which is acceptable in any of the components of the lithium battery, there are known external devices that stop the battery operation in the usual manner. If there is a local short circuit in the battery which can occur in an area of less than 50% of the electrode surface, or within the battery which is in contact with less than 50% of the electrode surface, more frequently with less than 15% of the electrode surface, the overall current drawn through the battery may not increase sufficiently to trigger~the current interrupting device and the cell or the battery can become damaged. In extreme cases the damage may result in explosion and fire. In the presence of the electrically conductive organic polymer laminate utilized in the composite electrode of the present invention , a short circuit occurring within a relatively small volume of the battery can increase the resistivity of a small volume of the organic polymer laminate in the proximity of the short circuit, thereby reducing the corresponding flow of current, thus avoiding, or at least reducing possible damage taking place in the lithium electrochemical cell or battery.
The polymer laminates are made of known blended mixtures SUBSTITUTE SHEET (RULE 26) WO 00/19552 - g ~ PCT/CA99/00863 of polyethylene of different chain lengths, mixtures of polyethylene and copolymers of ethylene and ethyl acrylate, mixtures of polyethylene and copolymers of ethylene and acrylic acid, copolymers of ethylene and ethyl acrylate, copolymers of ethylene and acrylic acid, polyolefins, polyesters, polyamides, polyethers, fluorinated ethylese-propylene copolymer, polyvinylidene fluoride and chemical equivalents, and contain carbon black or fine carbon of particle size less than lum, in less than 15 vol.%. The polymeric blend and carbon containing mixture is usually annealed in a known manner, and subsequently lamzTated. The preferred laminate thickness is less than 5~ptrt but more than 4pm, dictated by requirements of mechanical streng'h only.
The above listed blended polymer mixtures have melting temperatures at least 50'C higher than their resistivity switch temperature Tn. The obtained electrically conductive polymer laminates are cut to sizes which generally correspond to the appropriate lithium battery current collector. The carbon containing organic polymer laminate is placed over at least one the face of the current collector, and an electrode layer containing an electrode-active substance is deposited over the free face of the electrically conductive polymer laminate. The. electrode-active substance may be a conventional negative-active material in the case of the composite electrode being the anode, or a conventional positive-active substance for providing a composite cathode.
The anode or negative-active substance may be carbon particles capable of intercalating lithium, or a transition metal oxide, or a foil of lithium metal or an alloy thereof. It is known that lithium metal or. alloy may form dendrites in the recharging process which may lead to hot spots or short circuits in the lithium battery. ~ The present invention is particularly suitable to overcome the problems created by lithium metal dendrites. The cathode or positive-active substance may be a lithium-transition metal oxide or a similar compound capable of performing the same function. In the instance of. utilizing.conventional particulate eiectrode-active substances, such are mixed with a binder material, SUBSTITUTE SHEET (RULE 26) usually some fine carbon is also added to increase the conductivity of the mixture, and the electrode-active substance containing paste is laid in a suitable thickness over the conductive organic polymer laminate to yield a composite electrode for a rechargeable lithium battery.
The composite electrode is subsequently brought- in contact with a conventional lithium ion conducting electrolyte. The electrolyte may be a solid polymer electrolyte having dissociable lithium ions, or a porous separator layer impregnated with a lithium salt containing non-aqueous liquid, or similar substances utilized as electrolytes in lithium batteries. The other electrode of the rechargeable lithium battery may be another composite electrode of the present invention, or it may be a conventional lithium battery electrode.
In another arrangement the electrically conductive organic polymer laminate is covering both faces of the metallic current collector, and subsequently the electrode-active layer is deposited over both free faces of the conductive organic polymer laminate, thereby forming a double sided composite electrode.
In another embodiment the composite electrode has an additional adhesive layer between the electrode layer containing the electrode-active substance and the lithium ion conducting electrolyte. The object of the adhesive layer is to provide a medium for the lithium ions to transgress between the electrolyte and the electrode, as well as to eliminate possible trapping of gases between the electrode layer and the electrolyte layer. The adhesive layer usually comprises a non-aqueous solvent containing a lithium salt in a concentration which is less than concentration of lithium ions , present in the electrolyte. There are known methods for applying such adhesive layers.
A composite electrode, and a lithium battery having electrodes of opposite polarity both in the form of composite electrode made in accordance with this invention, are schematically represented on Fig. la and Fig.lb. Fig. la shows a composite electrode 10, assembled according to this SUBSTITUTE SHEET (RULE 26) invention, where 12 is the metallic current collector, 14 is the electrically conductive organic polymer laminate, and 16 is the electrode-active substance containing layer. Reference numeral 18 represents the assembled composite electrode, which may optionally, carry a lithium ion bearing adhesive layer 22.
Fig.lb represents schematically a lithium electrochemical cell 20, made of two composite electrodes of opposite polarity, and having electrolyte layer 26 between the composite anode 18, and composite cathode 24. In Fig.lb 12 and 12' are metallic current collector sheets, 14 and 14' are the electrically conductive organic polymer layers, which may be of the same composition or may be different, and 16 and 17 represent layers containing electrode-active components of opposite polarity. Lithium ion containing adhesive layers (not shown) may be inserted between each composite electrode and the appropriate face of the non-aqueous electrolyte.
An electrically conductive composition was prepared of a blended polymer mixture of low density polyethylene and ethylene vinyl acetate in a ratio of 5:1, containing 13o fine carbon, marketed as Shawinigan Black. The carbon was first blended with ethylene vinyl acetate and the low density polyethylene was then mixed into the first blend. The three component mixture was further blended at elevated temperature in a known manner, then extruded and annealed at 180~C for 18 hours, and the annealed polymer was laminated over a copper foil to yield current collector sheets of 27 um thickness.
The resistivity switch temperature Trs, of the above annealed polymeric mixture was found to be 98~C, about which the resistivity changed 2 orders of magnitude. The two-layer current collector was cut to rectangles of 62mm x 480mm, and one face of a rectangle was coated in 0.2 mm thickness with a graphite containing anode mixture. The anode mixture was composed of graphite powder marketed as "Lonza SFG-15"', and polyvinylidene fluoride binder added in 3 wt.%. A single layer of porous polypropylene separator, marketed under the name of "Celgard"*, and cut to the same size as the composite anode made of copper foil, electrically conducting ' TRADEMARK
polyethylene-ethylene vinyl acetate-carbon laminate and graphite layer, and was placed over the free face of the anode layer. The other side of the porous polypropylene separator was coated with a cathode mixture in 0.2 mm thickness, by the doctor's blade method. The cathode mixture contained lithium-cobalt oxide particles to which 3 wt. % polyvinylidene fluoride and 4 wt.% fine carbon had been added. The free face of the cathode layer was subsequently brought in contact with another rectangle of a two-layered current collector, which was made up of electrically conducting polyethylene-ethylene vinyl acetate-carbon polymer laminate and aluminum foil, having the aluminum foil on the external face. The assembled rechargeable lithium battery was wound, and then packaged into a plastic coated metallic cylinder of 65mm length and l8mm diameter, and subsequently filled with an electrolyte solution under vacuum and sealed. The electrolyte solution comprised ethylene carbonate-dimethyl carbonate in a ratio of l:l as solvent and contained LiPFs in 1 M concentration. The rechargeable lithium cell was charged to 4.2 volts. The cell showed an open circuit voltage of 4.08 V and had a capacity of 1540 mAh.
BXA~LE 2 A wound rechargeable lithium cell made as described in Example 1, was subjected to a nail penetration test by driving a 0.5 mm diameter nail into the cell packaged in the metallic cylinder. The lithium cell exhibited an open cell voltage of 4.05 V prior the nail penetration and 1.86 V after the nail penetration test. It can be seen that the open circuit voltage of the cell has dropped but there was no explosion or fire as a consequence of the damage caused by the nail.
In a comparative test a similar cylindrical lithium cell was made up with the same electrodes and electrolyte, but neither of its electrodes have been equipped with an electrically conductive organic polymer current collector laminate. The cell exploded which led to a small fire as a consequence of the nail penetration test.
An electrically conductive composition was prepared of SUBSTITUTE SHEET (RULE 26) a polymer of polybutene-1 containing 12 wt.% Shawinigan Black, which had been blended at elevated temperature, then extruded and annealed for 5 hours at 155~C, and the annealed polymer was laminated over a copper foil to yield current collector sheets of 28 um thickness. The resistivity switch temperature Trs, of this polymer was 92~C showing a resistivity change around this temperature of about 3 orders of magnitude. The two-layer current collector was cut to rectangles of 10 cm x 12 cm, and one face of a rectangle was coated in 0.2 mm thickness with a graphite containing anode mixture. The anode mixture was composed of graphite powder marketed as "Lonza SFG-15"', and polyvinylidene fluoride binder added in 3 wt.%. A composite cathode was prepared of lithium-cobalt oxide as the positive-active component in the cathode layer as described in Example 1, and of a two-layered current collector made up of an electrically conductive polybutene-1 and carbon black laminate carried on an aluminum foil. A solid polymer electrolyte of polyethylene oxide containing LiPF6 in 1 M concentration, cut to the same size as the composite anode and the composite cathode, was placed between the composite electrodes and the assembled lithium cell was packaged and sealed in the usual manner. The rechargeable lithium cell was charged at 4.2 volts and exhibited open circuit voltage of 4.05 V.
A planar rechargeable lithium cell made as described in Example 3, but having additionally a layer of polyvinylidene fluoride containing LiPF6 in 0.6 M concentration, coated on each side of the solid polymer electrolyte before the electrolyte was placed between the appropriate electrode-active layer bearing faces of the composite electrodes. The packaged lithium cell was charged as in Example 3 and showed similar open circuit voltages.
The particular advantage of a rechargeable lithium battery having a composite electrode bearing an electrically conductive organic polymer laminate, is that the latter is capable of protecting the lithium battery or the lithium electrochemical cell without affecting its efficiency. A
TRADEMARK
lithium battery pack containing several rechargeable lithium cells thus can continue to deliver energy even if one of the cells has been rendered defective due to a local short circuit or hot spot.
The use of electrically conductive organic polymer layers in contact with a metallic current collector and combined with an electrode layer has been described with respect to rechargeable lithium batteries. However, such combinations of metallic and electrically conductive organic polymer laminate current collectors can be used in other electrochemical cells where protection from the consequences of local high current and high temperature is desirable.
The foregoing has described the principles, preferred embodiments and modes of operation of the present invention. However, the invention should not be construed as limited to the particular embodiments discussed. Instead, the above-described embodiments should be regarded as illustrative rather than restrictive, and it should be appreciated that variations may be made in those embodiments by workers skilled in the art without departing from the scope of the present invention as defined by the following claims.
SUBSTITUTE SHEET (RULE 26)
FIELD OF INVBHTION
This invention is related to lithium batteries, in particular to current collectors utilized in rechargeable lithium batteries and electrochemical cells.
HaCKGROUND OF THE INV~iTION
Lithium batteries are often utilized in systems where high energy density per volume or weight is desirable.
Lithium batteries or cells may be button shaped, cylindrically or prismatically wound, or flat, composed of layers, known as planar cells or planar batteries. In most instances lithium based electrochemical cells are rechargeable, or are referred to as secondary batteries. Lithium electrochemical cells or batteries include a negative electrode or anode, containing a substance capable of intercalating lithium, or lithium metal or an alloy of lithium, as the negative active component. Th~
positive active component in the cathode is usually a chalcogenide of a transition metal and lithium, such as lithium-manganese oxide, lithium-cobalt oxide and similar type of compounds. The non-aqueous electrolyte may be a porous separator impregnated with an organic liquid containing a dissolved lithium salt, or a solid polymer containing a dissociable lithium compound, or composed of particles of solid polymer containing dissociable lithium compounds which particles are intermixed with one of the electrode active compound containing particles. Lithium batteries are usually equipped with current collectors in close proximity of the electrodes, which can be a metallic plate, rod, grating or foil, most frequently made of copper or aluminum, or similar metals or alloys thereof. The packaging of thin plate lithium cells often utilize metallic foils carried by a polymeric laminate, in addition to other polymeric layers designed to protect the rechargeable lithium battery from corrosion and mechanical damage. It is noted that.the packaging polymeric laminate carrying metallic foil is an insulator and is usually impermeable to liquids and gases. The lithium batteries under consideration may be composed of a single rechargeable lithium SUBSTITUTE SHEET (RULE 26) electrochemical cell or several rechargeable lithium cells stacked, folded or interconnected in a known manner to make up a lithium battery.
It is of importance that good contact is maintained between the current collector and the respective electrode so that the energy the lithium battery is capable of delivering is maximized under normal conditions. There are known methods to improve electrical contact between the cell electrode and the internal surface of the current collector.
One of such methods is designed to eliminate or reduce oxide formation on the surface of the metallic current collector.
In another method a conductive polymeric layer is inserted between the cuzrent collector and the electrode. Hy way of examples, a !ew patents which are directed to conductive polymeric layers, are discussed below. U.S.patent 5,262,254 issued to Koksbang et al. teaches an electronically conductive polymeric layer which can protect the metallic collector from attack by the cell electrolyte. U.S.patents 5,441,830 and 5,464,707, issued to Moulton et al. on August 15, 1995 and Movember 7, 1995, respectively, discuss adhesion-promoting polymeric mixtures bearing fine carbon powder, which are coated on a metallic foil, or on a metallic layer supported by a polymer laminate, and then cured or dried. The electrode paste is deposited on the cured or dried adhesion promoting coating. U.S.patents 5,464,706 and 5,547,782, issued to Dasgupta et al. on November 7, 1995 and August 20, 1995, respectively, disclose conductive polymeric layers loaded with ceramic or carbon particles of certain particle size range, inserted to be in contact with the electrode and the metallic collector surface, with the objective to diminish corrosion.
' U.S.patent 5,554,459, issued to Gozdz et al. on September 10, 199fi, teaches cleaned collector elements, more specifically a metallic grid, coated with an adherent, carbon loaded, electrically conductive polymer composition. U.S.patent 5,728,181, issued to Jung et nl. on March 17, 1998, discloses a conductive ink composed of.a long chained polymer and tine carbon coated on n current collector surface, onto which nn electrode layer is subsequently deposited, and the two layers SUBSTITUTE SHEET (RULE 2fi) carried by the current collector are then bonded together by radiation or heat curing. However, the resistivity of the above discussed conductive polymeric layers is likely to change with temperature gradually, and temperature induced structural changes within the solid polymeric layers are not known to be reversible. -High temperatures within the battery may be caused by too high overall currents during charging or discharging, or it can arise in the course of normal battery operation, brought about by local irregularities in the interaction between the cell components. Moreover, localized short circuits can lead to high currents within only a small portion of the cell, thereby creating a notable increase of temperature in the neighbourhood of the trouble area or a hat spot in the battery. The locally high temperature can damage the electrolyte or reduce the porosity of the separator, thereby blocking irreversibly the passage of ions, generate harmful gases which may ultimately lead to explosion and fire, or otherwise affect the safe operation of the battery. If some means can be found to diminish the high local current and thus reduce the high local temperature, the battery may be able to continue to operate nonaally. It is noted that there are several known methods whereby externally installed fuses or switches can stop the battery charging or discharging process , should the current rise beyond a permitted level. Some such fuses are known to operate reversibly. However, such fuses are located in a circuit external of the battery, or are installed in series with the cells, and respond only to the total current drawn through the battery or the cell.
There are known electrically conducting, carbon bearing, blended polymeric compositions, which are capable of exhibiting resistivity changes amounting to several orders of magnitude in a reversible manner in a pre-selected, relatively narrow temperature range. Such compositions are taught, for example, in U.S.patent 3,793,716, issued to R. Smith-Johannsen on February 26, 1974, and in U.S. patent 4,237,441, issued to P. van Konynenburg et al. on December 2, 1980. Compositions of such type are utilized in self-limiting electrical heating SUBSTITUTE SHEET (RULE 26) elements, in heat activated switches comprising electrodes separated by a polymer having positive heat coefficient, in reversible fuses, and in similar devices. A particular application of conductive polymers is described in U.S.patent 4,957,612, issued to R.F.Stewart et al. on Sept.l8, 1990, wherein a metallic core of an electrode is coated witri~an electrically conductive polymer,, which carries another conductive and electrochemically active component bearing polymer. The resistivities~ of the conductive polymers are different relative to one another at a given temperature.
There is a need for a thin conductive layer for insertion between the current collector and the electro-active layer in a rechargeable lithium battery, which is capable of reversible resistivity change of several orders of magnitude in response to locally high current flow and attendant local overheating within the battery, thereby being able to render protection from explosion and combustion.
SU1~1ARY OF THE INVENTION
An improved rechargeable lithium battery has been devised wherein an organic polymer laminate rendered electrically conductive by embedded electrically conductive particles, is forming a composite electrode in conjunction with an electrode layer containing an electrode-active substance, and a current collector. The electrically conductive organic polymer laminate has a thickness and faces which are in contact with the electrode layer and the current collector, respectively.
The electrically conductive organic polymer laminate has a positive temperature coefficient of resistivity, a resistivity switch temperature Tn, between 75 and 120°C, and the organic polymer laminate is capable of reversible resistivity change of at least 2 orders of magnitude within a 5° temperature band of the resistivity switch temperature T~., in a portion of the total volume of the electrically conductive organic polymer laminate. The electrically conductive particles embedded in the organic polymer laminate are very fine carbon particles or carbon black having particle size less than 0.1 Vim.
In another embodiment the composite electrode including an electrically conductive organic polymer laminate, carries SUBSTITUTE SHEET (RULE 26) a lithium ion containing adhesive layer on the face adjacent the electrolyte in the rechargeable lithium battery.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig.la and lb are schematic drawings of the cross-section of the composite electrode, and of a rechargeable lithium battery incorporating composite~electrodes of the present invention.
The preferred embodiments of the invention with reference to the drawings and working examples will now be described.
DETAILED DISCiISSION OF THE PREFERRED EtH30DIMEHTS
For the sake of clarity, the meaning of some of the expressions in the present discussion, as they are understood, will be given below:
An electrically conductive organic polymer is one wherein the charge carriers are electrons.
Positive temperature coefficient of resistivity is understood to mean that the resistivity, measured in ohm.cm, of the polymeric laminates under consideration in this discussion, increases with temperature. The tangent drawn to the values of resistivity of a solid plotted against temperature, gives the temperature coefficient of resistivity.
Resistivity switch temperature Tr~: the composition of the polymer laminates utilized in the present invention affects the nature of the electronic path and electronic mobility within the organic polymer laminate, such that the resistivity undergoes a rapid and substantial change around a given temperature. Below the resistivity switch temperature T~, the value of the resistivity in the polymer composition is a fraction of the resistivity above that temperature. The resistivity change with temperature is reversible.
As mentioned above, there are known polymer compositions having electrically conductive carbon particles dispersed therein, which are capable of undergoing a rapid and reversible change in resistivity with temperature. The type and mixture of polymers, the size and surface area of the carbon particles, the manner the particles are mixed with the polymers and the subsequent heat treatment , al l have an ef f ect on the value of the resistivity, and on the magnitude and SUBSTITUTE SHEET (RULE 26) temperature of the resistivity switch. It is noted that no invention per se, is claimed for the polymer compositions utilized in the improved rechargeable lithium battery of this invention. Most of the known carbon containing polymer compositions which have positive temperature coefficient of resistivity and are capable resistivity switch, utilize carbon particles of size less than 100 millimicron (m~) or O.l~m.
It has also been briefly discussed that the usual fields of utilization of organic polymer compositions having positive temperature coefficient of resistivity, are heater tapes, heat sensitive electric switches, heat sensitive fuses and electrical devices of similar nature. In such devices, it is of importance that substantially the entire surface of the polymer making the desired contact within the device is close to the same temperature, that is the volume corresponding to the operative surface of the electrically conductive polymer has substantially similar values of resistivity.
It has now been found that when known polymer compositions capable of undergoing crystallinity changes between 70 and 120'C, are loaded with carbon black or similar very fine carbon, of particle size less than 0.1 um, in concentrations less than 15 vol.%, blended, then heat treated or annealed in a known manner and laminated to sheets of less than 50um thick, then portions of the electrically conductive laminate obtained are capable of responding to local changes of temperature. if a portion of the laminate is at a temperature T1, which is different from the temperature Tz of the rest of laminate, then the resistivity of the laminate portion at T1 will be different from the resistivity of the laminate portion at temperature TZ. When T1 and TZ fall in the temperature range the polymer composition of the laminate is undergoing a reversible crystallinity change, that is close to the resistivity switch temperature Tr" then one portion of the electrically conductive polymer laminate can have a resistivity value which is several orders of magnitude different from the resistivity of the other portion. In other words, if a relatively small volume of the polymer laminate of such composition is heated to above its T=" the SUBSTITUTE SHEET (RULE 26) _ 7 resistivity of this volume will increase very significantly, and when the temperature drops below the temperature referred to as Tr" the lower resistivity is restored. It is believed, however, this reasoning is not considered binding, that the very small, less than O.l~Cm size of the carbon particles allows rapid rearrangement within the polymer laminate structure with temperature, thereby altering the path of the electronic charge carriers, which then results in substantial change in the resistivity of the polymer laminate. The crystallinity changes discussed above are the characteristic of certain polymer blend types, and are understood to be changes within a solid state taking place well below the melting temperature of the blend. Structural changes which are brought about by melting the polymeric mixture are excluded from the above considerations.
Rechargeable lithium batteries normally operate at temperatures below 70C. If during discharging or charging, the current in the battery goes above the level which is acceptable in any of the components of the lithium battery, there are known external devices that stop the battery operation in the usual manner. If there is a local short circuit in the battery which can occur in an area of less than 50% of the electrode surface, or within the battery which is in contact with less than 50% of the electrode surface, more frequently with less than 15% of the electrode surface, the overall current drawn through the battery may not increase sufficiently to trigger~the current interrupting device and the cell or the battery can become damaged. In extreme cases the damage may result in explosion and fire. In the presence of the electrically conductive organic polymer laminate utilized in the composite electrode of the present invention , a short circuit occurring within a relatively small volume of the battery can increase the resistivity of a small volume of the organic polymer laminate in the proximity of the short circuit, thereby reducing the corresponding flow of current, thus avoiding, or at least reducing possible damage taking place in the lithium electrochemical cell or battery.
The polymer laminates are made of known blended mixtures SUBSTITUTE SHEET (RULE 26) WO 00/19552 - g ~ PCT/CA99/00863 of polyethylene of different chain lengths, mixtures of polyethylene and copolymers of ethylene and ethyl acrylate, mixtures of polyethylene and copolymers of ethylene and acrylic acid, copolymers of ethylene and ethyl acrylate, copolymers of ethylene and acrylic acid, polyolefins, polyesters, polyamides, polyethers, fluorinated ethylese-propylene copolymer, polyvinylidene fluoride and chemical equivalents, and contain carbon black or fine carbon of particle size less than lum, in less than 15 vol.%. The polymeric blend and carbon containing mixture is usually annealed in a known manner, and subsequently lamzTated. The preferred laminate thickness is less than 5~ptrt but more than 4pm, dictated by requirements of mechanical streng'h only.
The above listed blended polymer mixtures have melting temperatures at least 50'C higher than their resistivity switch temperature Tn. The obtained electrically conductive polymer laminates are cut to sizes which generally correspond to the appropriate lithium battery current collector. The carbon containing organic polymer laminate is placed over at least one the face of the current collector, and an electrode layer containing an electrode-active substance is deposited over the free face of the electrically conductive polymer laminate. The. electrode-active substance may be a conventional negative-active material in the case of the composite electrode being the anode, or a conventional positive-active substance for providing a composite cathode.
The anode or negative-active substance may be carbon particles capable of intercalating lithium, or a transition metal oxide, or a foil of lithium metal or an alloy thereof. It is known that lithium metal or. alloy may form dendrites in the recharging process which may lead to hot spots or short circuits in the lithium battery. ~ The present invention is particularly suitable to overcome the problems created by lithium metal dendrites. The cathode or positive-active substance may be a lithium-transition metal oxide or a similar compound capable of performing the same function. In the instance of. utilizing.conventional particulate eiectrode-active substances, such are mixed with a binder material, SUBSTITUTE SHEET (RULE 26) usually some fine carbon is also added to increase the conductivity of the mixture, and the electrode-active substance containing paste is laid in a suitable thickness over the conductive organic polymer laminate to yield a composite electrode for a rechargeable lithium battery.
The composite electrode is subsequently brought- in contact with a conventional lithium ion conducting electrolyte. The electrolyte may be a solid polymer electrolyte having dissociable lithium ions, or a porous separator layer impregnated with a lithium salt containing non-aqueous liquid, or similar substances utilized as electrolytes in lithium batteries. The other electrode of the rechargeable lithium battery may be another composite electrode of the present invention, or it may be a conventional lithium battery electrode.
In another arrangement the electrically conductive organic polymer laminate is covering both faces of the metallic current collector, and subsequently the electrode-active layer is deposited over both free faces of the conductive organic polymer laminate, thereby forming a double sided composite electrode.
In another embodiment the composite electrode has an additional adhesive layer between the electrode layer containing the electrode-active substance and the lithium ion conducting electrolyte. The object of the adhesive layer is to provide a medium for the lithium ions to transgress between the electrolyte and the electrode, as well as to eliminate possible trapping of gases between the electrode layer and the electrolyte layer. The adhesive layer usually comprises a non-aqueous solvent containing a lithium salt in a concentration which is less than concentration of lithium ions , present in the electrolyte. There are known methods for applying such adhesive layers.
A composite electrode, and a lithium battery having electrodes of opposite polarity both in the form of composite electrode made in accordance with this invention, are schematically represented on Fig. la and Fig.lb. Fig. la shows a composite electrode 10, assembled according to this SUBSTITUTE SHEET (RULE 26) invention, where 12 is the metallic current collector, 14 is the electrically conductive organic polymer laminate, and 16 is the electrode-active substance containing layer. Reference numeral 18 represents the assembled composite electrode, which may optionally, carry a lithium ion bearing adhesive layer 22.
Fig.lb represents schematically a lithium electrochemical cell 20, made of two composite electrodes of opposite polarity, and having electrolyte layer 26 between the composite anode 18, and composite cathode 24. In Fig.lb 12 and 12' are metallic current collector sheets, 14 and 14' are the electrically conductive organic polymer layers, which may be of the same composition or may be different, and 16 and 17 represent layers containing electrode-active components of opposite polarity. Lithium ion containing adhesive layers (not shown) may be inserted between each composite electrode and the appropriate face of the non-aqueous electrolyte.
An electrically conductive composition was prepared of a blended polymer mixture of low density polyethylene and ethylene vinyl acetate in a ratio of 5:1, containing 13o fine carbon, marketed as Shawinigan Black. The carbon was first blended with ethylene vinyl acetate and the low density polyethylene was then mixed into the first blend. The three component mixture was further blended at elevated temperature in a known manner, then extruded and annealed at 180~C for 18 hours, and the annealed polymer was laminated over a copper foil to yield current collector sheets of 27 um thickness.
The resistivity switch temperature Trs, of the above annealed polymeric mixture was found to be 98~C, about which the resistivity changed 2 orders of magnitude. The two-layer current collector was cut to rectangles of 62mm x 480mm, and one face of a rectangle was coated in 0.2 mm thickness with a graphite containing anode mixture. The anode mixture was composed of graphite powder marketed as "Lonza SFG-15"', and polyvinylidene fluoride binder added in 3 wt.%. A single layer of porous polypropylene separator, marketed under the name of "Celgard"*, and cut to the same size as the composite anode made of copper foil, electrically conducting ' TRADEMARK
polyethylene-ethylene vinyl acetate-carbon laminate and graphite layer, and was placed over the free face of the anode layer. The other side of the porous polypropylene separator was coated with a cathode mixture in 0.2 mm thickness, by the doctor's blade method. The cathode mixture contained lithium-cobalt oxide particles to which 3 wt. % polyvinylidene fluoride and 4 wt.% fine carbon had been added. The free face of the cathode layer was subsequently brought in contact with another rectangle of a two-layered current collector, which was made up of electrically conducting polyethylene-ethylene vinyl acetate-carbon polymer laminate and aluminum foil, having the aluminum foil on the external face. The assembled rechargeable lithium battery was wound, and then packaged into a plastic coated metallic cylinder of 65mm length and l8mm diameter, and subsequently filled with an electrolyte solution under vacuum and sealed. The electrolyte solution comprised ethylene carbonate-dimethyl carbonate in a ratio of l:l as solvent and contained LiPFs in 1 M concentration. The rechargeable lithium cell was charged to 4.2 volts. The cell showed an open circuit voltage of 4.08 V and had a capacity of 1540 mAh.
BXA~LE 2 A wound rechargeable lithium cell made as described in Example 1, was subjected to a nail penetration test by driving a 0.5 mm diameter nail into the cell packaged in the metallic cylinder. The lithium cell exhibited an open cell voltage of 4.05 V prior the nail penetration and 1.86 V after the nail penetration test. It can be seen that the open circuit voltage of the cell has dropped but there was no explosion or fire as a consequence of the damage caused by the nail.
In a comparative test a similar cylindrical lithium cell was made up with the same electrodes and electrolyte, but neither of its electrodes have been equipped with an electrically conductive organic polymer current collector laminate. The cell exploded which led to a small fire as a consequence of the nail penetration test.
An electrically conductive composition was prepared of SUBSTITUTE SHEET (RULE 26) a polymer of polybutene-1 containing 12 wt.% Shawinigan Black, which had been blended at elevated temperature, then extruded and annealed for 5 hours at 155~C, and the annealed polymer was laminated over a copper foil to yield current collector sheets of 28 um thickness. The resistivity switch temperature Trs, of this polymer was 92~C showing a resistivity change around this temperature of about 3 orders of magnitude. The two-layer current collector was cut to rectangles of 10 cm x 12 cm, and one face of a rectangle was coated in 0.2 mm thickness with a graphite containing anode mixture. The anode mixture was composed of graphite powder marketed as "Lonza SFG-15"', and polyvinylidene fluoride binder added in 3 wt.%. A composite cathode was prepared of lithium-cobalt oxide as the positive-active component in the cathode layer as described in Example 1, and of a two-layered current collector made up of an electrically conductive polybutene-1 and carbon black laminate carried on an aluminum foil. A solid polymer electrolyte of polyethylene oxide containing LiPF6 in 1 M concentration, cut to the same size as the composite anode and the composite cathode, was placed between the composite electrodes and the assembled lithium cell was packaged and sealed in the usual manner. The rechargeable lithium cell was charged at 4.2 volts and exhibited open circuit voltage of 4.05 V.
A planar rechargeable lithium cell made as described in Example 3, but having additionally a layer of polyvinylidene fluoride containing LiPF6 in 0.6 M concentration, coated on each side of the solid polymer electrolyte before the electrolyte was placed between the appropriate electrode-active layer bearing faces of the composite electrodes. The packaged lithium cell was charged as in Example 3 and showed similar open circuit voltages.
The particular advantage of a rechargeable lithium battery having a composite electrode bearing an electrically conductive organic polymer laminate, is that the latter is capable of protecting the lithium battery or the lithium electrochemical cell without affecting its efficiency. A
TRADEMARK
lithium battery pack containing several rechargeable lithium cells thus can continue to deliver energy even if one of the cells has been rendered defective due to a local short circuit or hot spot.
The use of electrically conductive organic polymer layers in contact with a metallic current collector and combined with an electrode layer has been described with respect to rechargeable lithium batteries. However, such combinations of metallic and electrically conductive organic polymer laminate current collectors can be used in other electrochemical cells where protection from the consequences of local high current and high temperature is desirable.
The foregoing has described the principles, preferred embodiments and modes of operation of the present invention. However, the invention should not be construed as limited to the particular embodiments discussed. Instead, the above-described embodiments should be regarded as illustrative rather than restrictive, and it should be appreciated that variations may be made in those embodiments by workers skilled in the art without departing from the scope of the present invention as defined by the following claims.
SUBSTITUTE SHEET (RULE 26)
Claims (18)
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a rechargeable lithium battery having a negative electrode, a positive electrode, a metallic current collector adjacent each electrode and a non-aqueous electrolyte, the improvement comprising, that an organic polymer laminate having two opposing faces and rendered electrically conductive by embedded electrically conductive particles, thereby forming an electrically conductive organic polymer laminate, wherein said electrically conducting organic polymer laminate is inserted between at least one of the electrodes and the adjacent metallic current collector, thereby forming a composite electrode including said positive or said negative electrode, said electrically conductive organic polymer laminate having one face in contact with said metallic current collector and another face in contact with said positive or said negative electrode, said electrically conductive organic polymer laminate having a thickness, said thickness and said opposing faces defining a total volume, said electrically conductive organic polymer laminate having a positive temperature coefficient of resistivity, a resistivity switch temperature T rs, between 75 and 120°C, said electrically conductive organic polymer laminate being capable of reversible resistivity change of at least 2 orders of magnitude within a 5°temperature band of said T rs, and wherein said electrically conductive organic polymer laminate is capable of having said reversible resistivity change in a portion of the total volume of said electrically conductive organic polymer laminate.
2. An improved rechargeable lithium battery as claimed in claim 1, wherein said positive or said negative electrode included in said composite electrode, is comprising a blended mixture of an electrode-active substance, carbon particles and a binder, and said blended mixture is applied as a coherent electrode layer.
3. An improved rechargeable lithium battery as claimed in claim 1, wherein said reversible resistivity change in said portion of the total volume of said electrically conductive organic polymer laminate is caused by a localized temperature change greater than 5° relative to the average temperature of said rechargeable lithium battery.
4. An improved rechargeable lithium battery as claimed in claim 1 to 3, wherein said volume portion of said electrically conductive organic polymer laminate is less than 50 vol.% of the total volume of said electrically conductive organic polymer laminate.
5. An improved rechargeable lithium battery as claimed in claim 1 to 4, wherein said resistivity switch temperature T rs is at least 50° below the melting temperature of said electrically conductive organic polymer laminate.
6. An improved rechargeable lithium battery as claimed in claim 1 to 5, wherein said electrically conductive particles are selected from the group consisting of fine carbon and carbon black, and said electrically conductive particles have size less than 0.1µm.
7. An improved rechargeable lithium battery as claimed in claim 1 to 6, wherein said electrically conductive organic polymer laminate has thickness between 4 and 50µm.
8. An improved rechargeable lithium battery as claimed in claim 1 to 7, wherein said electrically conductive organic polymer laminate comprises at least one of the group consisting of polyethylene, copolymers of ethylene and ethyl acrylate, copolymers of ethylene and acrylic acid, polyolefins, polyethers, fluorinated ethylene-propylene copolymers, polyvinylidene fluoride, mixtures of polyethylene and a copolymer of ethylene and ethyl acrylate, and mixtures of polyethylene and a copolymer of ethylene and acrylic acid.
9. An improved rechargeable lithium battery as claimed in claim 8, wherein said electrically conductive organic polymer laminate comprises electrically conductive particles selected from the group consisting of fine carbon, and carbon black in less than 15 vol.%.
10. An improved rechargeable lithium battery as claimed in claim 2, wherein said electrode-active substance is selected from the group consisting of a positive active substance and a negative active substance.
11. An improved rechargeable lithium battery as claimed in claim 1 to 10, wherein said composite electrode is a composite negative electrode and said negative electrode included in said composite negative electrode is a lithium metal or a lithium alloy foil.
12. An improved rechargeable lithium battery as claimed in claim 2, wherein said coherent electrode layer has opposing faces, one face of said coherent electrode layer being in contact with said electrically conductive organic polymer laminate, and the other face of said coherent electrode layer is bearing a lithium ion containing adhesive coating.
13. An improved rechargeable lithium battery as claimed in claim 1 to 12, wherein said metallic current collector has two opposing faces and each face is in contact with an electrically conductive organic polymer laminate.
14. A rechargeable lithium battery comprising:
i) a first metallic current collector;
ii) a composite positive electrode comprising a first organic polymer laminate rendered electrically conductive by embedded electrically conductive particles, thereby forming a first electrically conductive organic polymer laminate, said first electrically conductive organic polymer laminate having a first thickness and a first pair of faces, said first thickness and said first pair of faces defining a first total volume, wherein said first electrically conductive organic polymer laminate, has a positive temperature coefficient of resistivity, a resistivity switch temperature T rs, between 75 and 120°C, said first electrically conductive organic polymer laminate being capable of reversible resistivity change of at least 2 orders of magnitude within a 5° temperature band of said T rs, and wherein said first electrically conductive organic polymer laminate is capable of having said reversible:
resistivity change in a portion of said first total volume of said first electrically conductive organic polymer laminate, one of said first pair of faces being in contact with said first metallic current collector, and the other of said first pair of faces of said first electrically conductive organic polymer laminate being in contact with a positive electrode further comprising a positive active substance, thereby forming a composite positive electrode including a positive electrode and a metallic current collector;
iii) a non-aqueous lithium ion conducting electrolyte having a third pair of faces; and iv) a composite negative electrode comprising a second organic polymer laminate rendered electrically conductive by embedded electrically conductive particles, thereby forming a second electrically conductive organic polymer laminate, said second electrically conductive organic polymer laminate having a second thickness and a second pair of faces, said second thickness and said second pair of faces defining a second total volume, wherein said second electrically conductive organic polymer laminate has a positive temperature coefficient of resistivity, a resistivity switch temperature T rs, between 75 and 120°C, said second electrically conductive organic polymer laminate being capable of reversible resistivity change of at least 2 orders of magnitude within a 5° temperature band of said T rs, and wherein said second electrically conductive organic polymer laminate is capable of having said reversible resistivity change in a portion of said second total volume of said second electrically conductive organic polymer laminate, one of said second pair of faces of said second electrically conductive organic polymer laminate being in contact with a negative electrode comprising a negative active substance, and the other of said second pair of faces being in contact with a second metallic current collector, thereby forming a composite negative electrode including a negative electrode and a second metallic current collector.
i) a first metallic current collector;
ii) a composite positive electrode comprising a first organic polymer laminate rendered electrically conductive by embedded electrically conductive particles, thereby forming a first electrically conductive organic polymer laminate, said first electrically conductive organic polymer laminate having a first thickness and a first pair of faces, said first thickness and said first pair of faces defining a first total volume, wherein said first electrically conductive organic polymer laminate, has a positive temperature coefficient of resistivity, a resistivity switch temperature T rs, between 75 and 120°C, said first electrically conductive organic polymer laminate being capable of reversible resistivity change of at least 2 orders of magnitude within a 5° temperature band of said T rs, and wherein said first electrically conductive organic polymer laminate is capable of having said reversible:
resistivity change in a portion of said first total volume of said first electrically conductive organic polymer laminate, one of said first pair of faces being in contact with said first metallic current collector, and the other of said first pair of faces of said first electrically conductive organic polymer laminate being in contact with a positive electrode further comprising a positive active substance, thereby forming a composite positive electrode including a positive electrode and a metallic current collector;
iii) a non-aqueous lithium ion conducting electrolyte having a third pair of faces; and iv) a composite negative electrode comprising a second organic polymer laminate rendered electrically conductive by embedded electrically conductive particles, thereby forming a second electrically conductive organic polymer laminate, said second electrically conductive organic polymer laminate having a second thickness and a second pair of faces, said second thickness and said second pair of faces defining a second total volume, wherein said second electrically conductive organic polymer laminate has a positive temperature coefficient of resistivity, a resistivity switch temperature T rs, between 75 and 120°C, said second electrically conductive organic polymer laminate being capable of reversible resistivity change of at least 2 orders of magnitude within a 5° temperature band of said T rs, and wherein said second electrically conductive organic polymer laminate is capable of having said reversible resistivity change in a portion of said second total volume of said second electrically conductive organic polymer laminate, one of said second pair of faces of said second electrically conductive organic polymer laminate being in contact with a negative electrode comprising a negative active substance, and the other of said second pair of faces being in contact with a second metallic current collector, thereby forming a composite negative electrode including a negative electrode and a second metallic current collector.
15. A rechargeable lithium battery as claimed in claim 14, wherein a lithium ion containing adhesive coating is inserted between said composite negative electrode comprising said negative active substance, and one of said third pair of faces of said non-aqueous lithium ion conducting electrolyte.
16. A rechargeable lithium battery as claimed in claim 14 or 15, wherein a lithium ion containing adhesive coating is inserted between said composite positive electrode comprising said positive active substance, and the other of said third pair of faces of said non-aqueous lithium ion conducting electrolyte.
17. A rechargeable lithium battery as claimed in claim 14, 15 or 16, wherein said first and said second electrically conductive organic polymer laminates have the same compositions and the same resistivity switch temperatures T rs.
18. A rechargeable lithium battery as claimed in claim 14, 15, 16 or 17, wherein said resistivity switch temperature T rs is at least 50°C below the melting temperature of said first and said second electrically conductive organic polymer laminates.
Applications Claiming Priority (3)
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| US09/161,664 US6159635A (en) | 1998-09-29 | 1998-09-29 | Composite electrode including current collector |
| US09/161,664 | 1998-09-29 | ||
| PCT/CA1999/000863 WO2000019552A1 (en) | 1998-09-29 | 1999-09-21 | Composite electrode including ptc polymer |
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| CA2345319A1 CA2345319A1 (en) | 2000-04-06 |
| CA2345319C true CA2345319C (en) | 2006-01-03 |
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| CA002345319A Expired - Fee Related CA2345319C (en) | 1998-09-29 | 1999-09-21 | Composite electrode including ptc polymer |
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Families Citing this family (61)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000182622A (en) * | 1998-12-17 | 2000-06-30 | Fujitsu Ltd | Battery and manufacturing method thereof |
| US6413676B1 (en) * | 1999-06-28 | 2002-07-02 | Lithium Power Technologies, Inc. | Lithium ion polymer electrolytes |
| DE60217086T2 (en) * | 2001-04-05 | 2007-04-12 | Electrovaya Inc., Mississauga | ENERGY CARRIER FOR VARIATING LOADS |
| US20040201365A1 (en) * | 2001-04-05 | 2004-10-14 | Electrovaya Inc. | Energy storage device for loads having variable power rates |
| CA2343489C (en) * | 2001-04-05 | 2007-05-22 | Electrofuel, Inc. | Energy storage device for loads having variable power rates |
| JP3934557B2 (en) * | 2001-05-22 | 2007-06-20 | エルジー・ケム・リミテッド | Non-aqueous electrolyte additive for improving safety and lithium ion secondary battery including the same |
| JP2003045415A (en) * | 2001-07-31 | 2003-02-14 | Nec Corp | Negative electrode for secondary battery |
| CN1260848C (en) * | 2002-03-28 | 2006-06-21 | Tdk株式会社 | Lithium secondary battery |
| US8431264B2 (en) | 2002-08-09 | 2013-04-30 | Infinite Power Solutions, Inc. | Hybrid thin-film battery |
| US8394522B2 (en) | 2002-08-09 | 2013-03-12 | Infinite Power Solutions, Inc. | Robust metal film encapsulation |
| US20070264564A1 (en) | 2006-03-16 | 2007-11-15 | Infinite Power Solutions, Inc. | Thin film battery on an integrated circuit or circuit board and method thereof |
| US8445130B2 (en) | 2002-08-09 | 2013-05-21 | Infinite Power Solutions, Inc. | Hybrid thin-film battery |
| US7993773B2 (en) | 2002-08-09 | 2011-08-09 | Infinite Power Solutions, Inc. | Electrochemical apparatus with barrier layer protected substrate |
| US8236443B2 (en) | 2002-08-09 | 2012-08-07 | Infinite Power Solutions, Inc. | Metal film encapsulation |
| US8404376B2 (en) | 2002-08-09 | 2013-03-26 | Infinite Power Solutions, Inc. | Metal film encapsulation |
| US8021778B2 (en) | 2002-08-09 | 2011-09-20 | Infinite Power Solutions, Inc. | Electrochemical apparatus with barrier layer protected substrate |
| US8728285B2 (en) | 2003-05-23 | 2014-05-20 | Demaray, Llc | Transparent conductive oxides |
| PL2290738T3 (en) * | 2003-09-23 | 2020-01-31 | Innolith Assets Ag | Electrochemical battery cell |
| CA2489849C (en) * | 2004-05-31 | 2011-05-10 | Sumitomo Electric Industries, Ltd. | Lithium secondary battery negative-electrode component material and lithium secondary battery |
| US7959769B2 (en) | 2004-12-08 | 2011-06-14 | Infinite Power Solutions, Inc. | Deposition of LiCoO2 |
| KR101127370B1 (en) | 2004-12-08 | 2012-03-29 | 인피니트 파워 솔루션스, 인크. | Deposition of licoo2 |
| TWI467840B (en) * | 2005-09-02 | 2015-01-01 | A123 Systems Inc | Nanocomposite electrodes and related devices |
| DE102005045032A1 (en) * | 2005-09-16 | 2007-03-22 | Varta Microbattery Gmbh | Galvanic element with safety device |
| CN100452491C (en) * | 2006-08-10 | 2009-01-14 | 武汉大学 | Granular electrode composite material with positive temp coefficient and preparing process thereof |
| CN101136471B (en) * | 2006-08-30 | 2010-06-16 | 比亚迪股份有限公司 | Electrode active material, preparation method thereof, and lithium ion secondary battery electrode |
| CN101523571A (en) | 2006-09-29 | 2009-09-02 | 无穷动力解决方案股份有限公司 | Masking and material confinement of a battery layer deposited on a flexible substrate |
| US8197781B2 (en) | 2006-11-07 | 2012-06-12 | Infinite Power Solutions, Inc. | Sputtering target of Li3PO4 and method for producing same |
| JP2008243708A (en) * | 2007-03-28 | 2008-10-09 | Matsushita Electric Ind Co Ltd | Non-aqueous electrolyte secondary battery and method for producing non-aqueous electrolyte secondary battery |
| US8268488B2 (en) | 2007-12-21 | 2012-09-18 | Infinite Power Solutions, Inc. | Thin film electrolyte for thin film batteries |
| CN101903560B (en) | 2007-12-21 | 2014-08-06 | 无穷动力解决方案股份有限公司 | Method for sputter targets for electrolyte films |
| JP4403524B2 (en) * | 2008-01-11 | 2010-01-27 | トヨタ自動車株式会社 | Electrode and manufacturing method thereof |
| US8518581B2 (en) | 2008-01-11 | 2013-08-27 | Inifinite Power Solutions, Inc. | Thin film encapsulation for thin film batteries and other devices |
| WO2009124191A2 (en) | 2008-04-02 | 2009-10-08 | Infinite Power Solutions, Inc. | Passive over/under voltage control and protection for energy storage devices associated with energy harvesting |
| JP2012500610A (en) | 2008-08-11 | 2012-01-05 | インフィニット パワー ソリューションズ， インコーポレイテッド | Energy device with integrated collector surface and method for electromagnetic energy acquisition |
| CN102150185B (en) | 2008-09-12 | 2014-05-28 | 无穷动力解决方案股份有限公司 | Energy device with integral conductive surface for data communication via electromagnetic energy and method thereof |
| WO2010042594A1 (en) | 2008-10-08 | 2010-04-15 | Infinite Power Solutions, Inc. | Environmentally-powered wireless sensor module |
| JP5313761B2 (en) * | 2009-05-08 | 2013-10-09 | パナソニック株式会社 | Lithium ion battery |
| CN102576828B (en) | 2009-09-01 | 2016-04-20 | 萨普拉斯特研究有限责任公司 | Printed circuit board with integrated thin-film battery |
| US8551660B2 (en) * | 2009-11-30 | 2013-10-08 | Tai-Her Yang | Reserve power supply with electrode plates joined to auxiliary conductors |
| EP2577777B1 (en) | 2010-06-07 | 2016-12-28 | Sapurast Research LLC | Rechargeable, high-density electrochemical device |
| CN103547451B (en) * | 2011-05-23 | 2016-03-02 | 株式会社钟化 | Multilayer conductive film, the collector body using it, battery and bipolar cell |
| JP2013120736A (en) * | 2011-12-08 | 2013-06-17 | Sony Corp | Electrode, battery, battery pack, electronic apparatus, electric vehicle, power storage device, and power system |
| EP2851981A4 (en) * | 2012-05-15 | 2016-06-22 | Uacj Corp | COLLECTOR, ELECTRODE STRUCTURE, NONAQUEOUS ELECTROLYTE BATTERY, AND ENERGY STORAGE COMPONENT, AND MANUFACTURER MANUFACTURING METHOD |
| JP6220784B2 (en) | 2012-07-13 | 2017-10-25 | 古河電気工業株式会社 | Current collector, electrode, secondary battery and capacitor |
| WO2014010681A1 (en) * | 2012-07-13 | 2014-01-16 | 古河電気工業株式会社 | Collector, electrode structure, nonaqueous electrolyte cell, and electricity storage component |
| KR20150102008A (en) | 2012-11-19 | 2015-09-04 | 후루카와 덴키 고교 가부시키가이샤 | Collector, electrode, secondary cell, and capacitor |
| US10573875B2 (en) | 2013-09-30 | 2020-02-25 | Hitachi Chemical Company, Ltd. | Cathode for lithium ion secondary battery and lithium ion secondary battery using the same |
| US9385374B2 (en) | 2014-04-01 | 2016-07-05 | Ppg Industries Ohio, Inc. | Electrode binder composition for lithium ion electrical storage devices |
| US20150280239A1 (en) | 2014-04-01 | 2015-10-01 | Ppg Industries Ohio, Inc. | Aqueous binder composition for lithium ion electrical storage devices |
| CN103956499B (en) * | 2014-04-15 | 2016-02-10 | 洛阳月星新能源科技有限公司 | A kind of safety coatings preparation method for plus plate current-collecting body in lithium ion battery |
| WO2016093095A1 (en) | 2014-12-08 | 2016-06-16 | 日立化成株式会社 | Positive electrode for lithium ion secondary batteries, and lithium ion secondary battery using same |
| CN107464948A (en) * | 2016-06-06 | 2017-12-12 | 万向二三股份公司 | A kind of highly secure lithium ion electrokinetic cell |
| WO2018168043A1 (en) * | 2017-03-14 | 2018-09-20 | 株式会社村田製作所 | Lithium-ion secondary cell |
| US10847834B1 (en) * | 2017-09-27 | 2020-11-24 | Apple Inc. | Corrosion resistant current collector for lithium metal anode |
| JP7387437B2 (en) * | 2017-09-29 | 2023-11-28 | 株式会社Ｇｓユアサ | Electrodes and storage elements |
| CN108110216A (en) * | 2017-12-30 | 2018-06-01 | 山东精工电子科技有限公司 | Anode slice of lithium ion battery and preparation method thereof and lithium battery |
| US11127938B2 (en) * | 2018-02-06 | 2021-09-21 | Pacesetter, Inc. | Electrodes for batteries and methods for making same |
| CN111416088B (en) * | 2020-03-26 | 2021-11-09 | 江苏厚生新能源科技有限公司 | Preparation method of lithium battery ceramic diaphragm |
| CN111564639B (en) * | 2020-05-28 | 2023-02-28 | 贝特瑞新材料集团股份有限公司 | Lithium ion battery pole piece, preparation method and application thereof |
| CN114614021A (en) * | 2022-03-30 | 2022-06-10 | 珠海中科先进技术研究院有限公司 | A kind of current collector with polymer coating and its preparation method and application |
| WO2025043119A1 (en) * | 2023-08-24 | 2025-02-27 | Sakuu Corporation | Polymer based current collector |
Family Cites Families (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3793716A (en) * | 1972-09-08 | 1974-02-26 | Raychem Corp | Method of making self limiting heat elements |
| US4237441A (en) * | 1978-12-01 | 1980-12-02 | Raychem Corporation | Low resistivity PTC compositions |
| US4545926A (en) * | 1980-04-21 | 1985-10-08 | Raychem Corporation | Conductive polymer compositions and devices |
| US4957612A (en) * | 1987-02-09 | 1990-09-18 | Raychem Corporation | Electrodes for use in electrochemical processes |
| US5464707A (en) * | 1992-10-29 | 1995-11-07 | Moulton; Russell D. | Electrically-conducting adhesion-promoters |
| US5441830A (en) * | 1992-10-29 | 1995-08-15 | Moulton; Russell D. | Electrically-conducting adhesion-promoters on conductive plastic |
| US5262254A (en) * | 1993-03-30 | 1993-11-16 | Valence Technology, Inc. | Positive electrode for rechargeable lithium batteries |
| US5464706A (en) * | 1994-03-02 | 1995-11-07 | Dasgupta; Sankar | Current collector for lithium ion battery |
| US5793276A (en) * | 1995-07-25 | 1998-08-11 | Tdk Corporation | Organic PTC thermistor |
| US5801612A (en) * | 1995-08-24 | 1998-09-01 | Raychem Corporation | Electrical device |
| US5554459A (en) * | 1996-01-23 | 1996-09-10 | Bell Communications Research, Inc. | Material and method for low internal resistance LI-ion battery |
| US5837164A (en) * | 1996-10-08 | 1998-11-17 | Therm-O-Disc, Incorporated | High temperature PTC device comprising a conductive polymer composition |
| JPH10125353A (en) * | 1996-10-17 | 1998-05-15 | Fuji Elelctrochem Co Ltd | Spiral type non-aqueous electrolyte battery |
| US5728181A (en) * | 1996-11-04 | 1998-03-17 | Motorola, Inc. | Electrodes for electrochemical cells and method of making same |
| EP0851517B1 (en) * | 1996-12-26 | 2001-03-21 | Mitsubishi Denki Kabushiki Kaisha | Electrode having PTC characteristics and battery using the same |
| US5968419A (en) * | 1997-12-08 | 1999-10-19 | Westinghouse Electric Company Llc | Conductive polymer compositions, electrical devices and methods of making |
-
1998
- 1998-09-29 US US09/161,664 patent/US6159635A/en not_active Expired - Lifetime
-
1999
- 1999-09-21 WO PCT/CA1999/000863 patent/WO2000019552A1/en not_active Ceased
- 1999-09-21 EP EP99944199A patent/EP1125334B1/en not_active Expired - Lifetime
- 1999-09-21 KR KR10-2001-7004003A patent/KR100414445B1/en not_active Expired - Fee Related
- 1999-09-21 CA CA002345319A patent/CA2345319C/en not_active Expired - Fee Related
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- 1999-09-21 DE DE69908803T patent/DE69908803T2/en not_active Expired - Lifetime
- 1999-09-21 BR BR9914124-8A patent/BR9914124A/en not_active Application Discontinuation
- 1999-09-21 CN CNB998115150A patent/CN1170327C/en not_active Expired - Fee Related
- 1999-09-21 JP JP2000572956A patent/JP3586195B2/en not_active Expired - Fee Related
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| CN1170327C (en) | 2004-10-06 |
| EP1125334A1 (en) | 2001-08-22 |
| KR100414445B1 (en) | 2004-01-07 |
| JP2002526897A (en) | 2002-08-20 |
| CA2345319A1 (en) | 2000-04-06 |
| BR9914124A (en) | 2001-06-19 |
| CN1320282A (en) | 2001-10-31 |
| KR20010075448A (en) | 2001-08-09 |
| DE69908803D1 (en) | 2003-07-17 |
| EP1125334B1 (en) | 2003-06-11 |
| US6159635A (en) | 2000-12-12 |
| AU5724099A (en) | 2000-04-17 |
| WO2000019552A1 (en) | 2000-04-06 |
| DE69908803T2 (en) | 2004-05-19 |
| JP3586195B2 (en) | 2004-11-10 |
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