JP2002203607A - Electrochemical cell consisting of alkaline metal cell or ion electrochemical cell including double collector cathode structure using same active material of different thicknesses - Google Patents

Abstract

PROBLEM TO BE SOLVED: To structure an electrochemical cell consisting of an alkaline battery cell or an ion electrochemical cell including a double collector cathode structure using the same active material of different thicknesses and improve capacity and usage efficiency of a lithium-containing cell. SOLUTION: The electrochemical cell is provided with is provided with an anode, a cathode structured so that a cathode material equipped as a first cathode structure having a first thickness be short-circuited with a second cathode structure with a thickness different from that of the first cathode structure and the second cathode structure made of the same cathode material as the first face the anode, and electrolyte solution activating the anode and the cathode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to the conversion of chemical energy into electrical energy. More specifically, the present invention provides a first cathode structure having a first thickness sandwiched between two current collectors, and a second cathode having a second thickness in contact with the opposite side of the current collector. And a novel sandwich-like cathode design with a structure. First
And the active material of the second structure is the same. In this cathode design, the only difference is that the first thickness is different from the second thickness, and it is preferred that the two second cathode structures have the same second thickness. This cathode design is advantageous for high discharge rate applications such as those required by cells that power implantable medical devices.

[0002]

BACKGROUND OF THE INVENTION In conventional cathode designs, electrode thickness affects cell capacity and cell discharge rate capability. In principle, the greater the thickness of the cathode in a given cell volume, the greater the cell capacity. However, in some cases,
Cathode discharge rate capability is greatly reduced when relatively low conductivity cathode active materials are used. The reason for this is that the resistance of any electrode is proportional to its thickness, that is, the distance from its outer surface to the current collector. The thickness of the electrode has an important problem in promoting the planning of the cell design model. Under certain circumstances, it is very difficult to predict how the difference in electrode thickness indicates the electrical or ionic resistance of a particular active material. As a result, the active material is left out of consideration for certain designs as not suitable for a power source.

However, the dual screen design of the present invention
The so-called “first cathode structure” arranged between the current collectors facing each other has a different thickness from the so-called “second cathode structure” that contacts the outside of the two current collectors.
Preferably, the thickness of the two second cathode structures in contact with both sides of the current collector is the same. Therefore, the first electrode which is sandwiched between the cathode current collectors and is directly in contact therewith
The cathode structure may be thicker or thinner than the thickness of the second structure, depending on the particular application. This facilitates model fabrication in terms of cell discharge rate capability, even for new designs or applications.

[0004] One type of chemical in which this form is particularly useful is lithium / vanadium silicate (Li / SV).
O) Included in cells. For this combination, the silver vanadium oxide cathode active material has a first thickness of a first thickness.
In configurations where the structure is sandwiched between two current collectors, it is possible to eliminate the binder and conductive diluent. The assembly is further sandwiched between two layers of silver vanadium oxide having a second structure having a second thickness different from the first thickness, a binder, and a conductive diluent. On the other hand, it is known that SVO can be squeezed into a cohesive structure that readily adheres to the current collector without the presence of a binder and a conductive diluent. As a result, a lithium cell with this form of cathode will have the same discharge rate capability as a conventional Li / SVO cell. At the same time, when the intermediate first structure is made thicker than the second structure and / or the non-active material is eliminated, these cells will have a higher Lithium content in the first structure due to the increased amount of active material in the first structure. / SVO indicates a capacity larger than the capacity of the cell.

[0005]

Accordingly, one object of the present invention is to improve the performance of lithium electrochemical cells by providing a new concept in electrode design.
It is a further object of the present invention to provide a cell design for improving the capacity and utilization efficiency of a lithium-containing cell.

[0006] These and other objects of the present invention are:
It will be more apparent to those skilled in the art by reference to the following description.

[0007]

SUMMARY OF THE INVENTION The electrochemical cell of the present invention has either primary battery characteristics or secondary recharge characteristics. For both primary and secondary types, the cell consists of an anodic active metal selected from Groups IA, IIA and IIIB of the Periodic Table of the Elements, such as lithium, sodium, potassium, and the like, and alloys thereof, and
i-Si, Li-Al, Li-B, Li-Mg and L
Includes intermetallic compounds including i-Si-B alloys and intermetallic compounds. The preferred metal comprises lithium. Another negative electrode comprises a lithium alloy, such as a lithium-aluminum alloy. The higher the weight of aluminum in the alloy, the lower the energy density of the cell.

In the case of a primary cell, the anode is a thin metal sheet of lithium material or a lithium foil, which is pressed or rolled onto an anode current collector made of metal, preferably nickel, to form a negative electrode. Form.
In a typical cell of the present invention, the negative electrode has the same material as the long tab or current collector, that is, preferably has a lead wire of nickel, and is integrally formed by welding or the like, Alternatively, it is connected to the cell / case of a conductive material of a case negative potential type by welding. Alternatively, the negative electrode is formed in some other geometric form, such as a bobbin, cylinder or pellet, allowing for an alternating low profile cell design.

In a secondary electrochemical system, the anode, the negative electrode, is preferably capable of inserting (intercalating) and removing (de-intercalating) an anode active material such as lithium alkali metal. Consists of anode material. Carbonaceous negative electrodes made of various forms of carbon (eg, coke, graphite, acetylene black, glassy carbon, etc.) that can reversibly maintain lithium species are preferably used as the anode material.
"Hairy carbon"
The material is particularly preferred because of its relatively high lithium retention capacity. "Hairy carbon (hairy ca
"rbon)" is the material disclosed in U.S. Patent No. 5,443,928 to Takeuchi et al., assigned to the assignee of the present invention and incorporated herein by reference. Graphite is another preferred material. Regardless of the form of the carbon, fibers of carbonaceous material are particularly advantageous.
This is because they have excellent mechanical properties that can be manufactured into robust electrodes that can withstand degradation during repeated charge / discharge cycles. In addition, the large surface area of the carbon fibers allows for rapid charge / discharge rates.

A typical negative electrode for a secondary cell is about 9
Made from 0 to 97% by weight of "hairy carbon" or a mixture of about 3 to 10% by weight of graphite of binder material. The binder material is preferably a fluoroplastic such as polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDE), polyethylene tetrafluoroethylene (ETFE), polyamide, polyimide, and mixtures thereof. This negative electrode mixture is cast, pressed, pressed on a current collector such as nickel, stainless steel, or copper foil or screen.
It is formed by rolling or otherwise contacting.

In either the primary cell or the secondary cell, the reaction at the positive electrode involves the transfer of ions that migrate from the negative electrode to the positive electrode in atomic or molecular form. In the case of a primary cell, the cathode reactant comprises carbonaceous chemistry, or at least a first transition metal chalcogenide component. This component may be in the matrix of a metal, metal oxide, or at least a first and second metal or oxide thereof and possibly a third metal or metal oxide, or a mixture of first and second metals or a host metal oxide. Is a mixed metal oxide composed of these metal oxides. The cathode active material also consists of metal sulfide.

The carbonaceous active material is preferably prepared from carbon and fluorine and includes graphitic and non-graphitic forms of carbon such as coke, charcoal or activated carbon. Fluorocarbons are represented by the formula (CF _x ) n, where x varies between about 0.1 and 1.9, preferably between about 0.5 and 1.2, and ₂ F) In _n , n is the number of widely varying monomer units.

The metal oxide or mixed metal oxide is formed by chemical addition or reaction or otherwise adheres to various metal oxides, metal sulfides and / or metal elements, preferably It further comprises a second active material formed by sol-gel formation, chemical vapor deposition or hydrothermal synthesis in a mixed state during the heat treatment. The active material thus formed is IB, IIB, IIIB,
It contains metals, oxides and sulfides of groups IVB, VB, VIB, VIIB and VIII and contains noble metals and / or
Or contains other oxide and sulfide mixtures. Preferred cathode active materials are reaction products of at least silver and vanadium.

[0014] One preferred mixed metal oxide has the general formula SM _x V ₂ O _y a transition metal oxide having, here the SM VIIB and VI from IB of the Periodic Table of the Elements
II, and in the general formula x
Is about 0.30 to 2.0 and y is about 4.5 to 6.0. Also, although not intended to be limiting, one representative cathode active material suitable for illustration is the general formula, A, in one of its many phases.
silver oxide vanadium with g _x V ₂ O _y ,
Β-phase silver oxide vanadium having the general formulas x = 0.35 and y = 5.8; γ-phase silver vanadium having the general formulas x = 0.80 and y = 5.40; x = 1.0
And ε-phase silver oxide having y = 5.5, a combination of these phases, and a mixed silver vanadium. A more detailed description of such a cathode active material reference is disclosed in U.S. Pat. No. 4,310,609 to Lian et al., Assigned to the assignee of the present invention, which is hereby incorporated by reference. .

[0015] Another preferred mixed transition metal oxide cathode material includes V ₂ O _z . Where z ≦ 5,
This material includes silver (II), silver (I), or silver (O)
Is bonded to silver oxide Ag ₂ O consisting of: and copper oxide CuO consisting of any of copper (II), copper (I) or copper (O), and is represented by the general formula: Cu _x Ag _y V ₂ O _z (CSVO) A mixed metal oxide having the following formula: Therefore, the synthetic (composite) cathode active material is metal oxide-metal oxide-
Can be described as metal oxide, metal-metal oxide-metal oxide, or metal-metal-metal oxide, and may include Cu _x Ag
range of material composition found in _y V ₂ O _z is preferably about 0.01 ≦ z ≦ 6.5. A common form of CSVO is Cu _0.16 Ag _0.67 V ₂ O _z , where z is about 5.5,
In _{Cu 0. 5 Ag 0.5 V 2 O} z, z is about 5.75. The oxygen content is represented by z, which is the exact stoichiometric ratio of oxygen in the CSVO, whether the cathodic material is prepared in an oxidizing atmosphere such as air or oxygen, or of argon, nitrogen and helium. This is because it is strongly influenced by whether the preparation is performed in such an inert atmosphere. For a more detailed description of this cathode active material, reference is made to U.S. Pat. No. 5,472,810 to Takeuchi et al. And U.S. Pat. No. 5,516,340 to Takeuchi et al., Both of which are incorporated herein by reference. Has been assigned,
Here, it is taken as a reference example.

In addition to the above-mentioned fluorocarbon, silver vanadium oxide, Ag ₂ O, Ag ₂ O ₂ , CuF ₂ , Ag ₂ Cr
O ₄ , MnO ₂ , V ₂ O ₅ , MnO ₂ , TiS ₂ , Cu
₂ S, FeS, FeS ₂ , copper oxide, copper vanadium oxide,
And mixtures thereof are considered as effective active materials.

In the secondary cell, the positive electrode is preferably made of a lithium oxide material that is stable in air and can be easily handled. Examples of this type of air-stable lithium oxide cathode active material include vanadium, titanium,
Chrome, copper, molybdenum, niobium (niobium), iron,
Includes oxides, sulfides, selenides and tellurides of metals such as nickel, cobalt and manganese.
More preferred oxides include LiNiO ₂ and LiMn ₂ O
₄ , LiCoO ₂ , LiCo _0.92 Sn _0.08 O ₂ and L
iCo _1-x Ni _x O ₂ .

To charge this kind of secondary cell, lithium ions constituting the positive electrode are inserted (intercalated) into the carbonaceous negative electrode by applying an externally generated potential to the cell. Is done. The applied recharging potential draws lithium ions from the cathode active material via the electrolyte, acts on the carbonaceous material of the negative electrode, and saturates the carbon. The resulting Li _x C ₆ negative electrode has an x range between 0.1 and 1.0. Here, a potential is generated in the cell and discharged by a normal method.

Another secondary cell structure involves inserting a carbonaceous material together with an active lithium material before incorporating the negative electrode into the cell. In this case, the positive electrode body is a solid and is not limited to this, but active materials of this kind include manganese dioxide, silver vanadium oxide, titanium disulfide, copper oxide, copper sulfide, iron sulfide, and iron disulfide. Consists of iron and carbon fluoride. However, this method must compromise the problems associated with treating lithium carbon oxide outside the cell. Lithium carbon oxide tends to react when it comes into contact with air or water.

The above-described cathode active materials, whether of secondary or secondary battery characteristics, are sandwiched in order to incorporate one or more of the active materials into a electrochemical cell by mixing them with a binder material. It is formed as an electrode body. Suitable binders are powdered fluoroplastics, more preferably powdered polytetrafluoroethylene or powdered polyvinylidene fluoride, and are present at about 1 to about 5% by weight of the cathode material. In addition, preferably up to about 10% by weight of a conductive diluent is added to the cathode mixture to enhance conductivity. Materials suitable for this purpose are acetylene black, carbon black and / or
Or graphite or metal powders such as powdered nickel, aluminum, titanium and stainless steel. Accordingly, a preferred cathode active mixture comprises a powdered fluoropolymer present at about 1-5% by weight, a conductive diluent present at about 1-5% by weight, and about 90-98% by weight of the cathode active material. .

According to the present invention, whether it is a primary battery or a secondary battery, a binder and a conductive diluent are mixed with any of the above-mentioned cathode active materials, if desired, and the mixture is formed into a sheet or plate. , Pellets and other similar shapes having first and second structures. Preferably, the first and second structures may include the same percentage regardless of the type of cathode active material, binder and conductive diluent.
In this regard, a feature that distinguishes the uniqueness of the first and second structures is their thickness.

Accordingly, the structures are individually squeezed on both sides of the current collector, so that they are in direct contact with the substrate. Preferably, the first cathode structure on the current collector side remote from the anode is on the opposite side of the current collector,
It has a thickness different from the thickness of the second structure facing the anode. More preferably, the first structure is thicker than the thickness of the second structure. In other words, a typical first structure having a greater thickness will never directly face the lithium anode.

Accordingly, one exemplary cathode design comprises a first cathode structure having a first thickness and a second cathode structure having a second thickness, both structures having the following dimensions that determine the cathode structure thickness: They are short-circuited to each other via a current collector with a form as a parallel connection. The cathode structure (x) / current collector / cathode structure (y) / current collector / cathode structure (x), where:
x and y represent thickness, and x is different from y,
Preferably x is less than y.

Another embodiment of the present invention is directed to a second thickness of the second thickness.
It has a first cathode structure of a first thickness sandwiched between the cathode structures, and the second cathode structure is short-circuited by being in direct contact with (the structure of) the first thickness. This cathode design has the following form of cathode structure thickness. Cathode structure (x) / current collector / cathode structure (x) / cathode structure (y) / cathode structure (x) / current collector / cathode structure (x), where x and y
Represents the thickness, and x is different from y, preferably x is less than y.

Another cathode design for a typical Li / SVO has the following form that determines the cathode structure thickness. SVO (x) / current collector / SVO (y) / current collector /
SVO (z), where x, y and z represent thickness, and x and z are less than y, or: SVO (x) / current collector / SVO (y); Here, x, y, and z represent thickness, x is less than y, and the SVO (x) thickness faces the anode.

An important aspect of the present invention is that the cathode structure facing the anode is generally thinner than the cathode structure remote from the anode. In this manner, the discharge rate capability of the particular cell chemistry is maintained such that the resistance of the structure closest to the anode does not increase. Normally, as the thickness of the electrode structure increases, the distance from the electrode surface to the current collector increases, so that the resistance value also increases. However, in the present invention, the energy density or discharge efficiency of the cell is increased by separating the cathode structure from the anode more than the distance from the nearby electrode structure. This is a function due to the effect of simply increasing the thickness and increasing the active material. Furthermore, among others, SVO, these active materials such as Ag ₂ O _2, Ag ₂ O and CF _x is, without binder or conductive diluent when contacted with the current collector, spaced from the anode The energy density of the cell is further increased by eliminating, or at least minimizing, the presence of inactive materials in the prepared cathode structure.

A cathode element for incorporation in an electrochemical cell according to the present invention is prepared by rolling, spreading or pressing the first and second cathode active materials into a suitable current collector. This current collector is made of stainless steel, titanium,
It is selected from the group consisting of tantalum, platinum, gold, aluminum, cobalt / nickel alloys, highly alloyed ferritic stainless steels containing molybdenum and chromium, and nickel-, chromium- and molybdenum-containing alloys. The preferred current collector material is titanium, and most preferably the titanium cathode current collector has a thin layer of graphite / carbon paint. A cathode prepared as described above may be in a form operatively associated with at least one or more plates of anodic material, or a "jelly roll"
Can be a wound strip with a corresponding strip anode material having a structure similar to the above.

In order to avoid internal short circuit conditions, the sandwich cathode is made of IA,
Separated from Group IIA or IIIB anodes. The separator is made of an electrically insulating material, and the separator material does not chemically react with the anode and cathode active materials, does not chemically react with the electrolytic solution, and is insoluble. In addition, the separator material has sufficient porosity to allow the electrolyte to pass therethrough during the electrochemical reaction of the cell. Illustrative separator materials include fabrics woven from fluoropolymer fibers. This fiber (fiber) contains polyvinylidene fluoride, polyethylene tetrafluoroethylene, polyethylene chlorotrifluoroethylene, used alone or
Or fluoropolymer microporous film, non-woven glass, polypropylene, polyethylene, glass fiber material, ceramics, name ZITEX
Polytetrafluoroethylene membrane commercially available under the name (Chemplast, Inc.), named CEL
A commercially available polypropylene membrane under GARD (Celanese Plastics Company, Inc.) and the name DEXIGLAS (CH Dex)
ter, Div. , Dexta Corporation).

The electrochemical cell of the present invention further includes a non-aqueous, ionically conductive electrolyte that acts as a medium for the transfer of ions between the anode and cathode during the electrochemical reaction of the cell. The electrochemical reaction at the electrode is
It involves the conversion of ions in the form of atoms or molecules that move from the anode to the cathode. Thus, non-aqueous electrolytes suitable for the present invention are substantially inert to the anodic and cathodic materials and have the physical properties required for ion transport, namely low viscosity, low surface tension and It exhibits wettability.

Suitable electrolytes include inorganic ionic conductive salts that are soluble in non-aqueous solvents. More preferably, the electrolyte contains an ionized alkali metal salt that melts in a mixture of an aprotic organic solvent consisting of a low-viscosity solvent and a high (absolute) dielectric constant solvent. The inorganic ion conductive salt acts as a mediator for anode ion transfer and intercalates with the cathode active material. Desirably, the ion-forming alkali metal salt is similar or similar to the alkali metal forming the anode.

In the case of an anode made of lithium,
And the alkali metal salt of the electrolyte is based on lithium
Salt. Alkali metal ions from anode to cathode
Known as a vehicle for transporting
The lithium salt is LiPF₆ , LiBF_Four , LiAsF
₆ , LiSbF₆ , LiClO_Four , LiO_Two , LiAl
Cl _Four , LiGaCl_Four , LiC (SO_Two CF_Three )_Three ,
LiN (SO_Two CF_Three )_Two , LiSCN, LiO_Three SC
F_Three , LiC₆ F_Five SO_Three , LiO_Two CCF_Three , LiS
O₆ F, LiB (C₆ H_Five )_Four , LiCF_Three SO_Two And
And mixtures of these.

The low-viscosity solvents which are advantageous in the present invention include tetrahydrofuran (THF), methyl acetate (MA), dyzilm, trizylm, tetrazylm, dimethyl carbonate (DMC), 1,2-dimethoxyethane (DME),
1,2-diethoxyethane (DEE), 1-ethoxy,
Esters, such as 2-methoxyethane (EME), ethyl methyl carbonate (EMC), methyl propyl carbonate, ethyl propyl carbonate, diethyl carbonate (DEC), dipropyl carbonate, and mixtures thereof; Ethers and cyclic ethers and dialkyl carbonates, and high dielectric constant solvents include cyclic carbonates, cyclic esters, propylene carbonate (PC), ethylene carbonate (EC), butylene carbonate, acetonitrile, dimethyl sulfoxide, dimethyl -Contains cyclic carbonates, cyclic esters and cyclic amides, such as formamide, dimethylacetamide, gamma-valerolactone, gamma-butyrolactone (GBL), N-methyl-pyrrrolidine (NMP), and mixtures thereof. In the present invention, the preferred anode is lithium metal, and the preferred electrolyte is a 50:50 volume ratio of a mixture of propylene carbonate as a preferred high absolute dielectric constant solvent and 1,2-dimethoxyethane as a preferred low viscosity solvent. 0.8M to 1.5M Li
AsF ₆ or LiPF ₆ .

A representative carbon / LiCoO ₂ couple 2
The preferred electrolyte for the next cell is EC: DMC: EM
C: Consists of a solvent mixture of DEC. The most preferred volume percent ranges for the various carbonate solvents are from about 20% to about 50% EC; from about 12% to about 75% DMC; and from about 5% to about 45%. With EMC; about 3
% To about 45% DEC. In a preferred form of the invention, the electrolyte activating the cell is DMC: E
It is equivalent with respect to the MC: DEC ratio. This is important for maintaining consistent and reliable cycling characteristics. DM in the presence of lithiated graphite due to the presence of low potential (anode) material in the charged cell
C: Unbalanced mixture of DEC (LiC ₆ -0.01 V vs. L
i / Li ⁺ ) are known to result in significant amounts of EMC. As the concentration of DMC, DEC and EMC changes, the cycling characteristics and cell temperature rating change.
Such unpredictability is unacceptable. This phenomenon is disclosed in detail in U.S. patent application Ser. No. 09 / 669,936, filed Sep. 26, 2000, assigned to the assignee of the present invention, and is incorporated herein by reference. Electrolytes containing the carbonate mixtures of the present invention exhibit a freezing point below -50 ° C, and lithium-ion secondary cells activated by such mixtures are very good at temperatures below -40 ° C. In addition to exhibiting discharge characteristics and charge / discharge cycle characteristics, it exhibits very excellent cycle characteristics even at room temperature.

The assembly of primary and secondary cells described herein is preferably in the form of a wound element structure. That is, the manufactured negative electrode, positive electrode, and separator are wound together in a “jelly roll” type shape, or the negative electrode is outside the roll, and the cell case and the negative potential type cell case are electrically connected. This is a "wound element cell laminate" that is electrically connected. Using suitable top and bottom insulators, the wound cell stack is inserted into a metal case of the appropriate size and dimensions. As long as this metal case coexists with the cell element, any metal material may be used.For example, a substance such as stainless steel, mild steel, nickel-plated mild steel, titanium, tantalum or aluminum is preferably used. .

The cell header consists of a metal disk-shaped body and has a first hole for receiving a glass-to-metal seal / terminal pin feedthrough and a second hole for filling with electrolyte. The glass used is CABAL 12, TA 23, FUSITE 4
It is of the corrosion resistant type with up to about 50% by weight of silicon, such as 25 or FUSITE 435.
The positive terminal pin feedthrough is preferably made of titanium, but molybdenum, nickel alloy, or stainless steel can also be used. The cell header is generally the same as the case material. The positive terminal pins supported within the glass-to-metal seal are then supported on a header welded to the case containing the electrode layers. The cell is then filled with the electrolyte described above, and the filling hole is hermetically sealed, for example by close welding of a stainless steel ball.

The above assembly describes a case negative potential cell which is a preferred structure of a typical primary or secondary cell of the present invention. As will be appreciated by those skilled in the art, the representative primary and secondary electrochemical systems of the present invention can be configured in a case positive potential configuration.

As mentioned above, the present cells are particularly useful for powering implantable medical devices such as cardiac defibrillators, cardiac pacemakers, nerve stimulators, drag pumps, and the like. . As is well known in the art, implantable cardioverter defibrillators are devices that require a power supply of approximately mid-discharge rate, consisting of a constant resistance load element provided by circuitry to perform, for example, heart rate sensing and pacing functions. It is. This medical device monitor function can be used from about 1 microamp to about 10
Requires 0 mA. Occasionally, a cardiac defibrillator delivers an electric shock to the heart, for example, during charging of a capacitor in the defibrillator, causing an irregular rapid arrhythmia that can lead to death if left unattended. To treat, it is generally necessary to generate a fast pulsed discharge load element. This medical device operating function requires a current of about 1 amp to about 4 amps.

The term "pulse" as used herein refers to a short burst of current with an amplitude much greater than the amplitude of the prepulse current immediately preceding the pulse. The pulse train is
It consists of at least two pulses of current supplied with or without a relatively short circuit opening between the pulses.

In this regard, an important aspect of the present invention is:
During a medical device monitor function, ie, at an intermediate rate of discharge, the first and second cathode structures are equivalent in both discharging at the same rate, ie, current The load can be distributed for the time being. However, during the medical device operating function, i.e., at a high rate of pulsed discharge, only the second cathode structure, which is outside the current collector and faces the anode, discharges. Thus, when the cell recovers the medical device monitoring function, the current collector in the middle of the first cathode structure acts to recharge the second cathode structure that has lost energy consumed during the medical device operating function. do. This charging continues until the first and second cathode structures have equal voltages. As a result, if the cell is subjected to a relatively high transient period of current discharge beyond that required for the device monitor function, the current will be high enough for the first cathode structure to recharge the second cathode structure. By the time the load decreases, the first and second cathodes become unbalanced.

It will be apparent that various modifications to the inventive concept described herein will be apparent to those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H01M 4/06 H01M 4/06 M 4/48 4/48 4/58 4/58 4/62 4/62 Z4 / 66 4/66 A 6/16 6/16 A (72) Inventor Esther S., Takeuchi 14051, New York, United States, East Amherst, Saint-Raphael, Court 38 F-term (reference) 5H017 AA03 AS01 AS10 CC00 DD05 EE01 EE04 EE05 EE06 5H024 AA01 AA02 AA03 AA04 AA06 AA07 AA11 AA12 CC12 DD15 DD17 DD19 EE01 EE03 EE09 FF14 FF15 FF16 FF17 FF18 FF19 HH01 HH04 HH08 HH13 HH15 5H012 A04 AM12 AM04 A0101 EJ04 EJ12 HJ04 HJ07 HJ10 HJ12 HJ17 5H050 AA07 AA08 BA06 BA16 CA02 CA05 CA07 CA08 CA09 CA10 CA11 CB12 DA02 DA10 DA11 EA02 EA03 EA08 EA09 EA10 EA24 FA02 FA05 FA12 HA04 HA07 HA10 HA12 HA17

Claims (55)

[Claims] B) a cathode active material provided as a first cathode structure having a first thickness is short-circuited with a second cathode structure having a second thickness different from the first thickness. A cathode having a second cathode structure facing the anode and comprising the same cathode active material as the first cathode structure; and c) an electrolyte activating the anode and the cathode. An electrochemical cell comprising: 2. The method according to claim 1, wherein the cathode active material is SVO, CSVO,
V ₂ O ₅ , MnO ₂ , LiCoO ₂ , LiNiO ₂ , L
iMnO ₂ , CuO ₂ , TiS ₂ , Cu ₂ S, FeS,
FeS ₂ , copper oxide, copper vanadium oxide, CF _x , Ag _{2
O, Ag 2 O 2, CuF} , Ag 2 CrO 4 and electrochemical cell of claim 1, mixtures thereof, et al made a group. 3. The electrochemical cell according to claim 1, wherein the first and second cathode structures are selected from binder materials and conductive additives and mixtures thereof. 4. The electrochemical cell according to claim 3, wherein the binder substance is a fluororesin powder. 5. The electrochemical cell according to claim 3, wherein the conductive additive is selected from carbon, graphite powder, acetylene black, titanium powder, aluminum powder, nickel powder, stainless steel powder, and a mixture thereof. . 6. The cathode has a thickness defined as cathode structure (x) / current collector / cathode structure (y) / current collector / cathode structure (z) as a structural thickness of the cathode. The electrochemical cell according to claim 1, wherein x, y and z in this case represent thickness. 7. The electrochemical cell according to claim 1, wherein x and z are both less than or greater than y. 8. The electrochemical cell according to claim 7, wherein x and z have the same thickness and are less than the thickness y. 9. x and z are different thicknesses, and
The electrochemical cell according to claim 7, wherein the thickness is less than y. 10. The cathode has a cathode structure (v) / current collector / cathode structure (w) / cathode structure (y) / cathode structure (x) / current collector / cathode structure (cathode structure thickness). z), wherein v, w, x, y and z represent the thickness, and v, w, x and z are all less than y, or y is An electrochemical cell according to claim 1. 11. The cathode has a thickness defined as cathode structure (x) / current collector / cathode structure (y), wherein x and y are thicknesses. The electrochemical cell of claim 1, wherein x is less than y and the cathode structure (x) faces the anode. 12. The cathode has a thickness defined as SVO (x) / current collector / SVO (y) / current collector / SVO (x) as a structural thickness of the cathode, and in this case, The electrochemical cell according to claim 1, wherein x and y represent a thickness, and x is less than y. 13. The cathode has a structure thickness of SVO (x) / current collector / SVO (x) / SVO
2. A film having a thickness defined in the form of (y) / SVO (x) / current collector / SVO (y), wherein x and y represent thickness, and x is less than y. An electrochemical cell according to claim 1. 14. The anode is lithium, and the cathode has a thickness defined as SVO (x) / current collector / SVO (y) as the structural thickness of the cathode, where x and y Represents the thickness, and x represents y
2. The electrochemical cell of claim 1 wherein the SVO (x) structure faces the lithium anode. 15. The electrochemical cell according to claim 1, wherein the anode comprises an alkali metal and the electrolyte is a non-aqueous chemical. 16. The electrochemical cell according to claim 1, having either primary or secondary chemical properties. 17. An electrochemical cell combined with an implantable medical device requiring a substantially constant discharge current during a monitoring function and requiring at least one current pulse during a medical operation function, comprising: a) An anode; b) a first cathode structure of a first thickness sandwiched between the first and second current collectors; and a first cathode structure opposite the first cathode structure.
And a second cathode structure having a second thickness in contact with at least one of the second current collector, wherein the second thickness is different from the first thickness, and the first and second cathode structures are the same. And c) an electrolyte activating the anode and the cathode, and a medical device. 18. The medical device of claim 17, wherein the medical device monitor function requires a current of about 1 microamp to about 100 milliamps, and the medical operating function of the medical device requires about 1 amp to about 4 amps. combination. 19. The combination according to claim 18, wherein the medical device monitoring function is provided by both the first and second cathode structures. 20. The combination of claim 18, wherein the medical operating function of the medical device is provided substantially by the second cathode structure. 21. The combination according to claim 17, wherein the first and second cathode structures are selected from binder materials and conductive additives and mixtures thereof. 22. An anode comprising lithium, a first cathode structure comprising SVO having a first thickness (x), and a second cathode structure comprising SVO having a second thickness (y).
O, where x is less than y and the first
18. The combination according to claim 17, wherein the cathode structure faces the anode. 23. The cathode has a thickness defined as SVO (x) / first current collector / SVO (y) / second current collector / SVO (x) as a structural thickness of the cathode. 18. The combination according to claim 17, wherein x and y represent a thickness in this case, and x is a thickness different from y. 24. The cathode has a thickness defined as SVO (x) / first current collector / SVO (y) / second current collector / SVO (z) as a structural thickness of the cathode. And in this case x, y and z represent the thickness,
The combination according to claim 17, wherein x and z have different thicknesses from y. 25. x and z are of the same thickness and y
25. The combination of claim 24, wherein the thickness is less than the thickness of the combination. 26. The combination of claim 24, wherein x and z are of different thicknesses and less than the thickness of y. 27. The cathode has a structure thickness of LiCoO ₂ (x) / first current collector / LiCoO 2
₂ (y) / second current collector / LiCoO ₂ (z), in which case x, y and z
Represents the thickness, and x and z are less than y. 28. The cathode active material is SVO, CSV
O, V ₂ O ₅ , MnO ₂ , LiCoO ₂ , LiNiO
₂ , LiMnO ₂ , CuO ₂ , TiS ₂ , Cu ₂ S, F
eS, FeS ₂ , copper oxide, copper vanadium oxide, CF _x ,
_{Ag 2 O, Ag 2 O 2} , CuF, claim 1 selected from Ag ₂ CrO _4, and mixtures et consisting of these groups
7. The combination according to 7. 29. The first and second current collectors are stainless steel, titanium, tantalum, platinum, gold, aluminum, cobalt / nickel alloy, high alloy ferritic stainless steel including molybdenum and chromium,
18. The combination of claim 17, wherein the combination is selected from the group consisting of: nickel-chromium, and a molybdenum-containing alloy. 30. The method of claim 17, wherein the first and second current collectors are titanium having a coating selected from the group consisting of a graphite / carbon material, iridium, iridium oxide, and platinum disposed thereon. The combination of the description. 31. A electrolyte comprising a non-aqueous chemical, a first solvent selected from esters, linear ethers, cyclic ethers, dialkyl carbonates, and mixtures thereof;
18. The combination according to claim 17, having a second solvent selected from a cyclic carbonate, a cyclic ester, a cyclic amide, and mixtures thereof. 32. The first solvent, wherein the first solvent is tetrahydrofuran (THF), methyl acetate (MA), diglyme, triglyme, tetraglyme, dimethyl carbonate (DMC),
1,2-dimethoxyethane (DME), 1,2-diethoxyethane (DEE), 1-ethoxy, 2-methoxyethane (EME), ethyl methyl carbonate, methyl propyl carbonate, ethyl propyl carbonate , Diethyl carbonate, dipropyl carbonate, and mixtures thereof, and the second solvent is propylene carbonate (PC), ethylene carbonate (EC), butylene carbonate, acetonitrile, dimethyl sulfoxide, dimethyl carbonate. 32. The combination according to claim 31, wherein the combination is selected from the group consisting of formamide, dimethylacetamide, gamma-valerolactone, gamma-butyrolactone (GBL), N-methyl-pyrrrolidine (NMP), and mixtures thereof. 33. LiPF₆ , LiBF_Four , LiAsF
₆ , LiSbF₆ , LiClO_Four , LiO_Two , LiAl
Cl_Four , LiGaCl_Four , LiC (SO_Two CF_Three)_Three ,
LiN (SO_Two CF_Three )_Two , LiSCN, LiO_Three SC
F_Three , LiC₆ F _Five SO_Three , LiO_Two CCF_Three , LiS
O₆ F, LiB (C₆ H_Five )_Four , LiCF _Three SO_Three ,
And resources selected from the group consisting of these compounds.
18. The combination according to claim 17, comprising a titanium salt. 34. An electrolyte comprising 0.8M to 1.5M LiAsF ₆ or LiPF ₆ dissolved in a 50:50 by volume mixture of propylene carbonate as a first solvent.
The combination according to claim 17, wherein the second solvent is 1,2-dimesoxyethane. 35. The combination of claim 17, wherein the anode comprises an alkali metal and the electrolyte comprises a non-aqueous chemical. 36. The combination according to claim 17, having any of the characteristics as a primary or secondary chemical battery. 37. The medical device, wherein the medical device is a cardiac pacemaker,
18. The combination according to claim 17, wherein the combination is selected from the group consisting of a cardiac defibrillator, a nerve stimulator and a drag pump. 38. A cathode comprising a cathode active material prepared as a) an anode; and b) a first cathode structure having a first thickness and a second cathode structure having a second thickness. A cathode structure having first and second major sides separated from each other, wherein at least one current collector comprises first and second major sides.
The first and second cathode structures are in contact with at least one of the major sides, the second cathode structure is in contact with at least one current collector on the opposite side of the first cathode structure, and the first and second cathode structures are the same. A cathode comprising a material, wherein the second cathode structure is thinner than the thickness of the first cathode structure and configured to face the anode; and c) an electrolyte activating the anode and the cathode. Become an electrochemical cell. 39. The electrochemical cell according to claim 38, wherein the first and second cathode structures are selected from binder materials and conductive additives and mixtures thereof. 40. An anode comprising lithium, a cathode having a thickness defined by the structure of SVO (x) / current collector / SVO (y) as a structure thickness of the cathode, and a cathode structure SVO (x) 39. The electrochemical cell of claim 38, wherein is facing the anode, x and y represent thickness, and x is less than y. 41. An anode is lithium, and a cathode has a thickness defined by a structure of CF _x (x) / current collector / CF _x (y) as a structure thickness of the cathode, and the cathode CF _x ( x) faces the anode,
39. The electrochemical cell according to claim 38, wherein x and y represent thickness and x is less than y. 42. The cathode active material is SVO, CSV
O, V ₂ O ₅ , MnO ₂ , LiCoO ₂ , LiNiO
₂ , LiMnO ₂ , CuO ₂ , TiS ₂ , Cu ₂ S, F
eS, FeS ₂ , copper oxide, copper vanadium oxide, CF _x ,
_{Ag 2 O, Ag 2 O 2} , CuF, Ag 2 CrO 4 and claim 3, mixtures thereof, et al made a group
9. The electrochemical cell according to 8. 43) a) a lithium anode; b) SVO, CSVO, V ₂ O ₅ , MnO ₂ , LiCo
O ₂ , LiNiO ₂ , LiMnO ₂ , CuO ₂ , TiS
₂ , Cu ₂ S, FeS, FeS ₂ , copper oxide, copper vanadium oxide, CF _x , Ag ₂ O, Ag ₂ O ₂ , CuF, Ag
A cathode active material selected from the group consisting of ₂ CrO ₄ and mixtures thereof;
A first cathode structure having a first thickness sandwiched between titanium current collectors; and a first cathode structure opposite to the first cathode structure and in contact with at least one of the first and second current collectors and facing the anode. A cathode comprising a second cathode structure having a second thickness that is less than the thickness of the first and second cathode structures, wherein the first and second cathode structures are comprised of the same cathode active material; and c) activating the anode and the cathode. And a non-aqueous electrolyte. 44. a) providing an anode; b) providing a first cathode structure having a first thickness shorted to a second cathode structure having a second thickness, wherein the first and second cathode structures have a first thickness. Preparing a cathode in which the second cathode structure is made of the same cathode active material and having a second thickness different from the first thickness; and c) activating the anode and the cathode with an electrolyte. A method for providing an electrochemical cell. 45. SVO, CSVO, V ₂ O ₅ , MnO
₂ , LiCoO ₂ , LiNiO ₂ , LiMnO ₂ , Cu
O ₂ , TiS ₂ , Cu ₂ S, FeS, FeS ₂ , copper oxide, copper vanadium oxide, CF _x , Ag ₂ O, Ag ₂ O
_2, CuF, Ag ₂ CrO ₄ and 45. The method of claim 44, mixtures thereof, et al made a group comprising the step of selecting a cathode active material. 46. The method of claim 44, further comprising providing first and second cathode structures having a non-active material selected from a binder material, a conductive additive, and mixtures thereof.
The method described in. 47. The form for defining the structure thickness of the cathode is as follows: cathode structure (x) / current collector / cathode structure (y)
45. The method of claim 44, comprising the step of providing a cathode / current collector / cathode structure (x), wherein x and y represent thickness and x is less than or greater than y. The method described in. 48. A mode for defining the structure thickness of the cathode is as follows: cathode structure (x) / current collector / cathode structure (y)
45. The method according to claim 44, wherein the structure comprises a current collector / cathode structure (z), wherein x, y and z represent thickness. 49. The method of claim 48, wherein x and z are both less than or greater than y. 50. x and z are the same thickness, and
49. The method of claim 48 wherein y is less than the thickness. 51. The method of claim 48, wherein x and z are different thicknesses and less than the thickness of y. 52. The cathode has the form of a cathode structure (x) / current collector / cathode structure (y) defining the structural thickness of the cathode, further comprising the cathode structure (x) facing the anode, 45. The method of claim 44, wherein x and y represent thickness, and x is less than y. 53. The cathode has the form SVO (x) / current collector / SVO (y) / current collector / SVO (z) defining the structural thickness of the cathode, where x,
The method of claim 44, wherein y and z represent thickness, and x and z are less than y. 54. The cathode has the form CF _x (x) / current collector / CF _x (y) / current collector / CF _x (z) that defines the structural thickness of the cathode, in which case x,
The method of claim 44, wherein y and z represent thickness, and x and z are less than y. 55. The method of claim 44, further comprising providing an electrolyte comprising an alkali metal anode and a non-aqueous chemical.
The method described in.