WO2015199101A1 - 非水電解質二次電池およびこれを複数個接続してなる組電池 - Google Patents
非水電解質二次電池およびこれを複数個接続してなる組電池 Download PDFInfo
- Publication number
- WO2015199101A1 WO2015199101A1 PCT/JP2015/068102 JP2015068102W WO2015199101A1 WO 2015199101 A1 WO2015199101 A1 WO 2015199101A1 JP 2015068102 W JP2015068102 W JP 2015068102W WO 2015199101 A1 WO2015199101 A1 WO 2015199101A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- positive electrode
- negative electrode
- active material
- electrolyte secondary
- positive
- Prior art date
Links
Images
Classifications
-
- 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
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/485—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/058—Construction or manufacture
- H01M10/0585—Construction or manufacture of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
-
- 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
-
- 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
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
-
- 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
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
- H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
-
- 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
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
- H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/50—Current conducting connections for cells or batteries
- H01M50/543—Terminals
- H01M50/547—Terminals characterised by the disposition of the terminals on the cells
- H01M50/548—Terminals characterised by the disposition of the terminals on the cells on opposite sides of the cell
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/50—Current conducting connections for cells or batteries
- H01M50/543—Terminals
- H01M50/547—Terminals characterised by the disposition of the terminals on the cells
- H01M50/55—Terminals characterised by the disposition of the terminals on the cells on the same side of the cell
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/50—Current conducting connections for cells or batteries
- H01M50/543—Terminals
- H01M50/552—Terminals characterised by their shape
- H01M50/553—Terminals adapted for prismatic, pouch or rectangular cells
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/60—Other road transportation technologies with climate change mitigation effect
- Y02T10/70—Energy storage systems for electromobility, e.g. batteries
Definitions
- the present invention relates to a non-aqueous electrolyte secondary battery and an assembled battery using the same.
- Non-aqueous electrolyte secondary batteries used in these fields are required to have high safety.
- batteries using a titanium compound as a negative electrode active material have been developed.
- a battery using a titanium compound as a negative electrode active material has a problem in that gas is generated due to a reaction between the electrolytic solution and the negative electrode active material, and cycle stability is lowered.
- Patent Document 1 In order to consume the gas generated in the battery, for example, in Patent Document 1, a gas removing agent including an organic polymer having a double bond and a catalyst is incorporated outside the active battery volume, and thus generated during operation of the battery.
- Technology that can consume gas is developed. However, this technology is for alkaline batteries, and there is no mention of any effect on non-aqueous electrolyte secondary batteries, and non-aqueous electrolyte secondary batteries exhibit significant performance degradation due to moisture. Incorporation of a gas removal agent into the non-aqueous electrolyte secondary battery is not suitable.
- Patent Document 2 describes that when spinel type lithium manganate is used as a positive electrode active material, the amount of gas generated in the battery is suppressed by adding lithium cobaltate or lithium nickelate. Yes. However, in such a mixed positive electrode, the positive electrode active material of spinel type lithium manganate and lithium cobaltate or lithium nickelate is exposed to the same potential environment at the time of charge / discharge. Due to the deterioration, the capacity maintenance rate may decrease in a long-term cycle test, and improvement is required.
- Patent Documents 3 to 5 disclose positive electrodes formed from a plurality of layers of a positive electrode active material layer containing spinel type lithium manganate and a positive electrode active material layer containing lithium cobalt oxide. Although these techniques are also considered to have a certain effect on gas suppression, there is a decrease in cycle characteristics during a cycle test that seems to be derived from lithium cobalt oxide, and needs to be improved.
- a positive electrode having a positive electrode active material mainly composed of a layered rock salt type compound as a positive electrode and a different kind of layered rock salt type compound are used.
- the titanium compound is used as the negative electrode active material. It has been found that even when a negative electrode is used, gas generation is suppressed and cycle characteristics are stabilized.
- the present invention relates to a plurality of types of positive electrodes having a positive electrode active material, a non-aqueous electrolyte, a negative electrode mainly composed of a titanium compound as a negative electrode active material, and an electrically insulating material sandwiched between the positive electrode and the negative electrode
- a non-aqueous electrolyte secondary battery having an encapsulant formed by enclosing a separator made of A separator sandwiching negative electrode, which is the negative electrode sandwiched between two separators, between one positive electrode and the other positive electrode adjacent thereto; and
- the plurality of types of positive electrodes are different from the layered rock salt type compound and the first positive electrode including a layered rock salt type compound as a positive electrode active material (hereinafter sometimes referred to as “first positive electrode active material”).
- the present invention relates to a non-aqueous electrolyte secondary battery comprising a second positive electrode mainly composed of a positive electrode active material of a kind (hereinafter sometimes referred to as “
- a preferred embodiment is to provide a non-aqueous electrolyte secondary battery including the separator sandwiched negative electrode on both sides of all the positive electrodes, and since the first positive electrode is charged from two negative electrodes on both sides, the minimum Since the gas suppression effect can be exhibited with the limited first positive electrode active material, the energy density increases.
- the first positive electrode is not discharged by at least an external load connection, except for natural discharge, during charge / discharge of the non-aqueous electrolyte secondary battery, while maintaining a constant charge state.
- the non-aqueous electrolyte secondary battery is characterized in that it is maintained in an encapsulated body, and the first positive electrode is held in a charged state for a long period of time. Is maintained for a long time, and the amount of gas generated can be reduced.
- the terminal further includes a terminal connected to each of the first positive electrode, the second positive electrode, and the negative electrode, the terminal having a terminal extending portion extending outside the enclosure.
- a positive electrode terminal extension portion of the first positive electrode wherein the positive electrode terminal extension portion of the second positive electrode is present separately from the non-aqueous electrolyte secondary battery, Spontaneous discharge of the first positive electrode is suppressed, and the effect of reducing the amount of gas generated lasts for a long period of time.
- the layered rock salt type compound is a non-aqueous electrolyte secondary battery in which the layered rock salt type compound is one or more layered rock salt type compounds selected from the group consisting of lithium cobaltate, lithium cobalt nickel aluminum oxide, and lithium cobalt nickel manganate. It is to do.
- a preferred embodiment is to provide a nonaqueous electrolyte secondary battery in which the positive electrode active material of a different type from the layered rock salt type compound is spinel type lithium manganate.
- the non-aqueous electrolyte secondary battery according to the present invention has excellent cycle stability even when a titanium compound is used for the negative electrode, and the amount of gas generated during the cycle test is dramatically reduced.
- FIG. 1 is a conceptual cross-sectional view of one embodiment of a nonaqueous electrolyte secondary battery 10 of the present invention. It is a conceptual diagram of one Embodiment of the electrode group which concerns on this invention. It is an external appearance conceptual diagram of another embodiment of the nonaqueous electrolyte secondary battery 10 of this invention.
- the non-aqueous electrolyte secondary battery 10 of the present invention includes a plurality of types of positive electrodes 2, a non-aqueous electrolyte, a negative electrode 1, and a separator 3 made of an electrically insulating material sandwiched between the positive electrode 2 and the negative electrode 1.
- the nonaqueous electrolyte according to the present invention responsible for lithium ion conduction exists on at least the surfaces of the positive electrode 2, the negative electrode 1, and the separator 3 and inside thereof.
- a terminal 7 is individually connected to each of the positive electrode 2 and the negative electrode 1 at least for each of the electrodes, and each terminal 7 has a terminal extending portion 9 at least outside the enclosure 8 according to the present invention.
- the first positive electrode 21 and the second positive electrode 22 may be connected to the same positive electrode terminal 72, or may be connected to different positive electrode terminals 72-1 and 72-2.
- different positive electrode terminals 72-1 and 72-2 In order to make the gas generation suppression effect of the present invention more effective by controlling the first positive electrode 21 and the second positive electrode 22 to separate potential environments, respectively, different positive electrode terminals 72-1 and 72-2. It is preferable that it is connected to.
- first positive electrode terminal 71 from the enclosure 8 of the nonaqueous electrolyte secondary battery 10 of the present invention, at least the negative electrode terminal 71, the first positive electrode terminal 72-1, and the second positive electrode terminal 72 as the terminal extending portions 9 of the terminals 7. -2, it is preferable that some of the three types of terminals extend to the outside.
- a plurality of first positive electrodes 21, second positive electrodes 22, and negative electrodes 1 may exist.
- the total number of first positive electrodes 21 is A, and B of them is first positive terminal 72-1-1 (not shown).
- a plurality of first positive electrodes 21 are connected to a plurality of different first positive terminal 72-1, so that AB pieces are connected to first positive terminals 72-1-2 (not shown). Also good. From the viewpoint of economy and operability, one of each of the three types of terminals, the negative electrode terminal 71, the first positive electrode terminal 72-1, and the second positive electrode terminal 72-2, contains three terminal extensions 9 in total. It is preferable to extend from the body 8.
- the first positive electrode 21 and the second positive electrode 22 according to the present invention are in different potential environments.
- the terminal extension 9 of the first positive terminal 72-1 is preferably present separately from the terminal extension 9 of the second positive terminal 72-2. More preferably, the enclosure 8 is electrically insulated from the surrounding environment.
- the terminal extension 9 of the first positive terminal 72-1 and the terminal extension 9 of the second positive terminal 72-2 are separated, that is, the first positive terminal 72-1.
- Separately connecting the second positive electrode terminal 72-2 and electrically connecting a different positive electrode terminal 7 to each electrode means that the positive electrode terminal 72-1 of the first positive electrode 21 and the positive electrode terminal of the second positive electrode 22 are connected.
- 72-2 is physically non-contacted, and the first positive electrode 21 and the second positive electrode 22 are electrically de-energized in terms of conduction of electrons and holes except for ionic conduction. .
- the different positive electrode terminals 7 are electrically non-energized in this sense, that is, electrically insulated in this sense, and the first positive electrode 21 and the second positive electrode 22 are respectively connected to each other.
- the first positive electrode 21 is continuously electrically isolated during the subsequent charge / discharge.
- the method is not particularly limited.
- the first positive terminal 72-1 and the negative terminal 71 are used.
- the terminal extension 9 of the first positive electrode terminal 72-1 is covered with an insulating sheet, and then the second positive electrode terminal 72-2 and the negative electrode terminal.
- the first positive electrode 21 and the second positive electrode 22 according to the present invention are each one in the enclosure 8 according to the present invention, or When a plurality of the first positive electrodes 21 are included, it is preferable that all the first positive electrodes 21 are connected to the same first positive electrode terminal 72-1, and all the second positive electrodes 22 are connected to the same second positive electrode terminal 72-2. .
- the non-aqueous electrolyte secondary battery of the present invention is preferably applied to the present invention by laminating a laminate of negative electrode / separator / positive electrode, or by laminating a plurality of laminates via a separator and attaching other necessary members.
- the electrode group according to the present invention is enclosed in an exterior such as a laminate film to form an enclosure, and the enclosure is used as a main body. You may make it have the enclosure covered with the metal can of square shape, ellipse shape, cylindrical shape, coin shape, button shape, and sheet shape. From the viewpoint of easily disposing the first positive electrode according to the present invention, it is more preferable to make a laminated battery having an encapsulated body in which a laminate laminated via a separator is covered with a laminate film.
- the enclosure and the exterior may be provided with a mechanism for releasing the gas generated in the enclosure, and a mechanism for collecting the gas is provided as a gas collection bag in the enclosure, for example. May be.
- the number of stacked layers can be appropriately set so as to express a desired voltage value and battery capacity.
- the battery of the present invention has the first positive electrode in addition to the second positive electrode used for normal charge / discharge in order to obtain the gas generation suppression effect of the present invention.
- the first positive electrode according to the present invention contains a specific active material, specifically, a layered rock salt type compound.
- the reference numerals of the constituent members may be omitted.
- the first positive electrode according to the present invention is preferably used for normal charging / discharging in a state of being electrically isolated after being charged to a predetermined charging state, and the effect of the present invention is prolonged. More preferably, from the viewpoint of maintaining over a period, when the charge amount in the charged state of the first positive electrode is decreased across the period of use for normal charging / discharging, only the first positive electrode is separately charged. More preferably, the charge state of the first positive electrode is measured, and when the charge state falls below a predetermined charge state, the separate charge is performed.
- the predetermined charged state of the first positive electrode is a charged state described below. That is, in a half-cell with the first positive electrode as the working electrode and lithium as the counter electrode, constant current and constant potential charging is performed at 4.25 V with respect to the lithium electrode, and the observed current value is the capacity of the set battery capacity.
- the SOC is 20% or more and SOC 95% or less, and deterioration of the first positive electrode can be suppressed, so that the SOC is 30% or more and SOC 90%. It is particularly preferred that
- the first positive electrode according to the present invention may be present in the encapsulated body according to the present invention, or a plurality of the first positive electrodes may be present. It is preferable that it is 1% or more and less than 10% of the total weight of the total positive electrode active material of the second positive electrode, which can be present in the inclusion body according to the present invention. From the viewpoint of good balance, it is more preferably 2% or more and 5% or less.
- the first positive electrode is electrically isolated in a predetermined charging state, the capacity does not contribute to the actual charge / discharge, so the amount of the active material of the first positive electrode is the second. When the amount of the positive electrode is greater than the amount of the active material, the energy density of the battery is reduced accordingly.
- the position of the first positive electrode in the encapsulant according to the present invention is not particularly limited, but in a preferred embodiment, when the laminate is laminated, in the cross section when the electrode group is cut in the lamination direction, Arranging outside the second positive electrode is preferable because the gas suppression effect is large.
- the non-aqueous electrolyte secondary battery of the present invention can have a plurality of enclosures according to the present invention.
- the negative electrode terminals 71 of each enclosure are connected in series or in parallel, and the second positive electrode terminal 72- 2 in series or in parallel (when the negative terminal 71 is connected in series, the second positive terminal 72-2 is also connected in series, and when the negative terminal 71 is connected in parallel, the second positive terminal 72-2 is also connected in parallel.
- the assembled battery of the present invention can be obtained by connecting a plurality of such nonaqueous electrolyte secondary batteries of the present invention, that is, by appropriately connecting the battery negative terminal and the battery positive terminal.
- the battery terminals are connected in series or in parallel as appropriate depending on the desired size, capacity, and voltage.
- a control circuit is attached to the assembled battery in order to confirm the state of charge of each battery and improve safety.
- the positive electrode and the negative electrode according to the present invention are portions where active materials of the respective electrodes contributing to the electrode reaction are present, and members including this portion include, for example, current collectors and terminals described later, and are positive electrode members or negative electrode members.
- the positive electrode and the negative electrode refer to portions where the active material of each electrode is present, not this member.
- the positive electrode member and the negative electrode member are formed with a material layer containing an active material of each electrode on a conductive current collector, and a conductive terminal is connected thereto.
- the positive electrode and the negative electrode in this specification refer to a portion in which this material layer is formed and encapsulated in the encapsulant according to the present invention.
- the current collector and the terminal may be separate members, but may be the same member including the current collector portion and the terminal portion.
- Such a positive electrode member or negative electrode member according to the present invention includes at least a material layer and a current collector portion of each electrode that is the positive electrode and the negative electrode, and a part of a terminal portion of each electrode according to the present invention.
- the extending portions of these terminals are extended by being encapsulated in a state of being pulled out of the enclosing body, and this terminal extending portion is electrically connected to an external device and charged / discharged. It will be used for such purposes.
- the area on the outer shape used for the electrode reaction between each positive electrode and each negative electrode according to the present invention that is, the surface of each electrode opposite to the current collector of the material layer,
- the area of the external surface exposed to the non-aqueous electrolyte according to the present invention (sometimes referred to as “polar reaction surface” in this specification) is highly reliable by improving the uniformity of the electrode reaction at each electrode.
- the ratio of the maximum area / minimum area, which is the variation, is preferably 1 or more and 1.3 or less, more preferably for each positive electrode or each negative electrode, from the viewpoint of making the battery of FIG. It is preferable to make the area the same for each positive electrode and each negative electrode.
- the area of the electrode reaction surface of the positive electrode and the negative electrode can be controlled, for example, by controlling the coating width at the time of slurry coating for forming a material layer on a current collector as a preferred embodiment. .
- the electric capacity per unit area of each positive electrode and the electric capacity per unit area of each negative electrode according to the present invention are high-reliability batteries by improving the uniformity of the electrode reaction at each electrode, and From the viewpoint of making the battery compact, the ratio (electric capacity per maximum area) / (electric capacity per minimum area) is preferably 1 or more and 1.3 or less, more preferably for each positive electrode. Or it is to make the electric capacity per area the same for every negative electrode, More preferably, it is making the electric capacity per area the same for every positive electrode and every negative electrode.
- the method of controlling the capacitance per unit area of the positive electrode and the negative electrode is controlled by the weight of the material layer formed per unit area of the current collector when forming the material layer on the current collector as a preferred embodiment. For example, it can control by the coating thickness at the time of material layer coating.
- the ratio of the electric capacity per area of the positive electrode and the negative electrode balances the electrode reaction at the positive electrode and the electrode reaction at the negative electrode. From the viewpoint of obtaining a highly reliable battery, it is preferable to satisfy the following formula (1), and D is more preferably larger than C.
- C represents the electric capacity per 1 cm 2 of the positive electrode
- D represents the electric capacity per 1 cm 2 of the negative electrode
- the capacity of the negative electrode may be smaller than that of the positive electrode, so that the potential of the negative electrode becomes a lithium deposition potential during overcharge, which may cause a risk of short-circuiting the battery.
- F / E is greater than 1.2, there is a negative electrode portion that does not face the positive electrode, and therefore there is a possibility that the negative electrode active material that does not participate in the battery reaction in that portion may cause an excessive side reaction. Yes, unnecessary gas generation accompanying this side reaction may occur in the enclosure.
- any shape can be used as long as it has conductivity and can be used as a core material of each electrode. It is preferable to use a film-like current collector foil.
- a metal for example, positive electrode
- aluminum that does not react with the positive electrode or negative electrode potential on the surface of aluminum, an alloy of aluminum, or a metal other than aluminum (copper, SUS, nickel, titanium, or an alloy thereof).
- aluminum coated with aluminum or copper for the negative electrode can be used.
- the material of the current collector used for the positive electrode is more preferably high-purity aluminum typified by JIS standards 1030, 1050, 1085, 1N90, 1N99 and the like from the viewpoint of stability in the positive electrode reaction atmosphere.
- the thickness of the current collector is not particularly limited, but is preferably 10 ⁇ m or more and 100 ⁇ m or less. If it is less than 10 ⁇ m, handling is difficult from the viewpoint of production, and if it is thicker than 100 ⁇ m, it is disadvantageous from an economic viewpoint.
- the material constituting the material layer includes at least the active material of each electrode, and in addition to this, in order to improve the performance of the active material layer, a conductive additive or a binder may be included. It is preferable that a positive electrode or a negative electrode is formed by forming a mixture containing these materials as a material layer on a current collector.
- the density of the material layer is preferably 1.0 g / cm 3 or more and 4.0 g / cm 3 or less after the rolling. If it is less than 1.0 g / cm 3 , the contact between the active material of each electrode and the current collector or the conductive aid becomes insufficient, and the electron conductivity may decrease, and the internal resistance of the battery may increase. is there. On the other hand, if it is larger than 4.0 g / cm 3 , the nonaqueous electrolyte is less likely to penetrate into the material layer of each electrode, the lithium conductivity is lowered, and the internal resistance of the battery may be similarly increased.
- the density of the material layer of the positive electrode is more preferably 2.0 g / cm 3 or more by performing rolling, which is a preferred embodiment, and is preferably 2.2 g / cm 3 or more and 3.5 g / cm. 3 or less is more preferable, and 2.5 g / cm 3 or more and 3.0 g / cm 3 or less, which is the most balanced, is particularly preferable.
- the method for removing the solvent is preferable because it is easy to dry using an oven or a vacuum oven.
- the atmosphere for removing the solvent include room temperature or high temperature air, inert gas, and vacuum.
- the temperature at which the solvent is removed is not particularly limited, but it should be 60 ° C. or more and 300 ° C. or less from the viewpoint of shortening the time required for removing the solvent while preventing decomposition of the material of the material layer and deterioration of the binder. It is more preferable to carry out at 80 ° C. or higher and 250 ° C. or lower, and it is more preferable to carry out at 200 ° C. or lower.
- before and after formation of the material layer of each electrode either may be before or after.
- the preparation of the slurry is not particularly limited, a mixture containing a conductive additive, a binder, and the like together with the active material and a solvent can be uniformly mixed. From the viewpoint of workability, it is preferable to use a rotating / revolving mixer, a planetary mixer, and a thin film swirl mixer. Although the production of the slurry is not particularly limited, it may be produced by adding a solvent to the mixture, or may be produced by mixing the mixture and the solvent together.
- the solvent is preferably a non-aqueous solvent or water.
- the non-aqueous solvent is not particularly limited, and examples thereof include N-methyl-2-pyrrolidone (NMP), dimethylformamide, dimethylacetamide, methyl ethyl ketone, methyl acetate, ethyl acetate, and tetrahydrofuran.
- NMP N-methyl-2-pyrrolidone
- dimethylformamide dimethylacetamide
- methyl ethyl ketone methyl acetate
- ethyl acetate tetrahydrofuran.
- the solid content concentration of the slurry is preferably 30 wt% or more and 80 wt% or less from the viewpoint of setting the viscosity to a value suitable for forming the material layer.
- each active material The active material of each electrode is generally supplied as a powder.
- the number average particle diameter on the appearance of the active material powder is preferably from 0.2 ⁇ m to 50 ⁇ m, more preferably from 0.5 ⁇ m to 30 ⁇ m, and more preferably from 1 ⁇ m to 30 ⁇ m, from the viewpoint of handleability. More preferably, it is more preferably 3 ⁇ m or more and 20 ⁇ m or less.
- the number average particle diameter on the appearance indicates the number average particle diameter of the secondary particles in which the primary particles are aggregated. If the particles are spherical, the diameter is the same. If the particles are not spherical, the maximum side of the particles is determined from the SEM and TEM images. It is a value obtained by measuring each particle and calculating the average by the number. In order to calculate the average of the number average particle diameter, it is preferable to observe 10 or more arbitrary particles by the SEM observation.
- the specific surface area of the powder of the active material is preferably from 0.05 m 2 / g or more 50 m 2 / g, is 0.1 m 2 / g or more 20 m 2 or less Is more preferable.
- the specific surface area of the layered rock salt type compound contained in the positive electrode active material of the first positive electrode according to the present invention has a good balance between the suppression of gas generation and the suppression of material deterioration, so that it is 0.1 m 2 / g or more and 3 m 2 / More preferably, it is g or less.
- the specific surface area in the present specification is a value that can be calculated based on the measurement result by the BET method.
- the conductive aid is not particularly limited, but the conductive aid contained in the positive electrode material layer is preferably a carbon material because of its low cost, and the conductive aid contained in the negative electrode material layer is a metal material or carbon.
- a material can be used, and the metal material is preferably at least one selected from the group consisting of copper and nickel.
- Examples of the carbon material include natural graphite, artificial graphite, vapor-grown carbon fiber, carbon nanotube, acetylene black, ketjen black, and furnace black. These carbon materials may be used alone or in combination of two or more.
- the amount of the conductive additive contained in the material layer is preferably 1 part by weight or more and 30 parts by weight or less, more preferably 2 parts by weight or more and 15 parts by weight or less with respect to 100 parts by weight of the positive electrode active material in the positive electrode material layer.
- the negative electrode material layer it is preferably 0.5 parts by weight or more and 30 parts by weight or less with respect to 100 parts by weight of the negative electrode active material, and more preferably 1 weight because the balance between output and energy density is good. Part to 15 parts by weight.
- the positive electrode or negative electrode material layer according to the present invention preferably contains a binder in order to bind each active material to the current collector.
- the binder is not particularly limited, but at least one selected from the group consisting of polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), styrene-butadiene rubber, polyimide, and derivatives thereof may be used. preferable.
- the amount of the binder contained in each material layer of the positive electrode or negative electrode according to the present invention is 1 part by weight or more and 30 parts by weight from the viewpoint of balancing the binding force and the energy density with respect to 100 parts by weight of the active material of each electrode. It is preferable to set it as follows, and more preferably 2 parts by weight or more and 15 parts by weight or less. By making it within such a range, the conductivity of each electrode of the positive electrode or the negative electrode is ensured, and the adhesion between the active material of each electrode and the conductive additive is maintained, and each material layer and the current collector It is possible to obtain sufficient adhesiveness.
- the binder is preferably dissolved or dispersed in a non-aqueous solvent or water from the viewpoint of easy production of the positive electrode or the negative electrode.
- the non-aqueous solvent is not particularly limited, and examples thereof include N-methyl-2-pyrrolidone (NMP), dimethylformamide, dimethylacetamide, methyl ethyl ketone, methyl acetate, ethyl acetate, and tetrahydrofuran. You may add a dispersing agent and a thickener to these.
- Negative electrode> The negative electrode according to the present invention has a function of accepting lithium ions from the electrolyte during charging of the battery of the present invention and receiving electrons via the negative electrode terminal. It has a function of releasing ions and supplying electrons through the negative electrode terminal.
- a negative electrode may be referred to as a material layer (hereinafter referred to as a “negative electrode active material layer”) including at least an active material (hereinafter also referred to as “negative electrode active material”) on the current collector. ) Is preferably formed as a member, and a part of such a negative electrode member is enclosed in the encapsulant according to the present invention, and a part of the negative electrode terminal extending part is formed outside the encapsulant. As a result, it is electrically connected to an external device.
- the main component of the negative electrode active material is a titanium compound.
- the titanium compound has a smaller expansion and contraction of the active material in the lithium ion insertion / desorption reaction than a conventional negative electrode active material represented by LiCoO 2 .
- a conventional negative electrode active material represented by LiCoO 2 As compared with the conventional negative electrode having a negative electrode active material containing conventional negative electrode active material represented by LiCoO 2 as a main component, a small stirring effect of the nonaqueous electrolyte due to expansion and contraction. From the above, it is necessary to secure a negative electrode specific surface area larger than that of the conventional negative electrode as a place where a certain amount or more of lithium ions are inserted and removed.
- the specific surface area of the negative electrode according to the present invention is preferably 1 m 2 / g or more and 100 m 2 / g or less. If it is smaller than 1 m 2 / g, there are few places where lithium ions can be inserted and removed, so that the desired battery capacity may not be taken out. On the other hand, if it is larger than 100 m 2 / g, side reactions other than lithium ion desorption / insertion, for example, decomposition reaction of the nonaqueous electrolyte easily proceed, and as a result, there is a possibility that a desired battery capacity cannot be taken out. is there.
- the specific surface area of the negative electrode should be 2 m 2 / g or more and 70 m 2 / g because a place for lithium ion desorption / insertion capable of expressing a desired capacity is secured and there are few side reactions other than lithium ion desorption / desorption. Is more preferable. It is more preferable that the specific surface area of the negative electrode be 3 m 2 / g or more and 50 m 2 / g because the side reaction proceeds the least and is well balanced when lithium ions are desorbed and inserted.
- the specific surface area of the negative electrode can be controlled by the type and blending ratio of the negative electrode active material, the conductive additive, and the binder, or can be controlled by compressing the electrode to a desired thickness.
- the negative electrode active material according to the present invention requires a titanium compound as a main component, that is, the titanium compound is contained as a component exceeding 50% by mass with respect to the total negative electrode active material.
- a negative electrode active material an element other than lithium and titanium, such as Nb, may be contained at a ratio of less than 50% by mass, and a negative electrode active material other than a titanium compound contains 80% by mass or more of a titanium compound. Is preferably 20% by mass or less, and more preferably a titanium compound which may contain trace amounts of elements other than lithium and titanium such as Nb.
- titanium compound titanic acid compounds, lithium titanate, titanium dioxide and the like are preferable. These titanium compounds may be covered with a carbon material, a metal oxide, a polymer, or the like in order to improve conductivity or stability.
- titanate compound is preferably a H 2 Ti 3 O 7, H 2 Ti 4 O 9, H 2 Ti 5 O 11, H 2 Ti 6 O 13, H 2 Ti 12 O 25, cycle characteristics H 2 Ti 12 O 25 is more preferable because it is stable.
- the lithium titanate preferably has a spinel structure or a ramsdellite type, and more preferably has a molecular formula represented by Li 4 Ti 5 O 12 .
- the spinel structure is preferable because the expansion and contraction of the active material in the lithium ion insertion / desorption reaction is small.
- the titanium dioxide is preferably an anatase type or a bronze type (TiO 2 (B)), and more preferably a bronze type since insertion and desorption of lithium proceeds efficiently. Also, a mixture of anatase type and bronze type may be used.
- the nonaqueous electrolyte secondary battery of the present invention uses two types of positive electrodes, a first positive electrode and a second positive electrode, and the first positive electrode has a layered rock salt type compound as a main component. It has the material layer containing. Each of the first positive electrode and the second positive electrode may be one or plural.
- the electrode exhibiting the gas generation suppressing effect is the first positive electrode having a layered rock salt type active material.
- the layered rock salt type active material has an effect of occluding gas, and is considered to have a higher gas suppression effect particularly when the charged state is maintained.
- the positive electrode active material of the first positive electrode according to the present invention needs to contain a layered rock salt type compound, preferably 20% by mass or more and 100% by mass or less, and has a sufficient gas generation suppressing effect. From the viewpoint of tightening, it is more preferable that it is contained as a main component, that is, a component exceeding 50% by mass, more preferably 80% by mass or more.
- lithium nickel composite oxide for example, LiNiO 2
- LiCoO 2 lithium cobalt composite oxide
- Nickel cobalt composite oxide for example, LiNi 1-y Co y O 2
- lithium cobalt oxide LiCoO 2
- lithium cobalt nickel aluminum oxide LiNi 0.8 Co 0.15 al 0.05 O 2
- One type of these positive electrode active materials may be used, or two or more types may be used.
- the surface of the layered rock salt type compound according to the present invention may be coated with an organic substance such as polyethylene glycol, an inorganic substance such as aluminum oxide, magnesium oxide, zirconium oxide or titanium oxide, and a carbon material.
- the positive electrode active material of the second positive electrode is the positive electrode used for normal charge and discharge, which is the object of the battery of the present invention. Therefore, the material used as the positive electrode active material of the second positive electrode is a material that is less likely to undergo material expansion and contraction during normal charging and discharging, and is less prone to material deterioration. This is preferable from the viewpoint of a long battery.
- the positive electrode active material of the second positive electrode according to the present invention needs to contain a positive electrode active material of a type different from the layered rock salt type compound as a main component.
- the type of positive electrode active material different from the layered rock salt type compound means a material different from the positive electrode active material used as the main component in the first positive electrode. More specifically, for example, when a specific layered rock salt type compound is used as the main component of the positive electrode active material in the first positive electrode, a layered rock salt type other than the specific layered rock salt type compound in the second positive electrode. A compound can be used as the main component of the positive electrode active material.
- the spinel type lithium manganate is Li 1 + x M y Mn 2 ⁇ xy O 4 (0 ⁇ x ⁇ 0.2, 0 ⁇ y ⁇ 0.6, M is a group of 2 to 13 and in the third and fourth periods. Element).
- M is at least one selected from elements belonging to Groups 2 to 13 and belonging to the 3rd to 4th cycles.
- manganese elution is unlikely to occur, and Al, Mg, Zn, Ni, Co, Fe and Cr are preferable, Al, Mg, Zn, Ni and Cr are more preferable, and Al, Mg, Zn and Ni are further preferable.
- x ⁇ 0 the capacity of the positive electrode active material tends to decrease.
- Li 1 + x Al y Mn 2 ⁇ xy O 4 (0 ⁇ x ⁇ 0.1, 0 ⁇ y ⁇ 0.1)
- Li 1 + x Ni y Mn 2 because the effect of improving stability is large.
- -x-y O 4 (0 ⁇ x ⁇ 0.1,0 ⁇ y ⁇ 0.6)
- Li 1 + x Mg y Mn 2-x-y O 4 (0 ⁇ x ⁇ 0.1,0 ⁇ y ⁇ 0 .1)
- Li 1 + x Zn y Mn 2 ⁇ xy O 4 (0 ⁇ x ⁇ 0.1, 0 ⁇ y ⁇ 0.1
- Li 1 + x Cr y Mn 2 ⁇ xy O 4 (0 ⁇ x) 1 type selected from ⁇ 0.1, 0 ⁇ y ⁇ 0.1) is preferred, and Li 1 + x Al y Mn 2 ⁇ xy O 4 (0 ⁇ x ⁇ 0.1, 0) can be obtained.
- the main component of the first positive electrode active material is lithium nickel composite oxide, lithium cobalt composite oxide, lithium nickel cobalt composite oxide, lithium nickel cobalt manganese.
- the main component is a main component of the first positive electrode active material selected from lithium manganese composite oxide, lithium nickel composite oxide, lithium cobalt composite oxide, lithium nickel cobalt composite oxide, and lithium nickel cobalt manganese composite oxide.
- Different layered rock salt type compounds, spinel type lithium manganate and The combination is at least one lithium compound selected from the group consisting of lithium phosphorus oxide having an emission structure is preferred.
- the main component of the first positive electrode active material is an excess of lithium nickel composite oxide, lithium cobalt composite oxide, lithium nickel cobalt composite oxide, lithium nickel cobalt manganese composite oxide, and lithium. It is at least one layered rock salt type compound selected from the group consisting of a solid solution of lithium manganese composite oxide and lithium transition metal composite oxide, and the main component of the second positive electrode active material is spinel type lithium manganate Combinations are listed.
- the main component of the first positive electrode active material is lithium cobalt oxide (LiCoO 2 ), lithium cobalt nickel aluminum oxide (LiNi 0.8 Co 0.15 Al 0.05 O 2 ), and cobalt nickel.
- At least one selected from the group consisting of lithium manganate (LiNi x Co y Mn 1-yz O 2 , x + y + z 1), and the main component of the second positive electrode active material is spinel type lithium manganate
- a particularly preferable combination is a combination in which the main component of the second positive electrode active material is the above-described spinel type lithium manganate which is preferable from the viewpoint of high voltage charge / discharge.
- nylon, cellulose, polysulfone, polyethylene examples thereof include polypropylene, polybutene, polyacrylonitrile, polyimide, polyamide, PET, and woven fabrics, nonwoven fabrics, microporous membranes, etc., which are a combination of two or more thereof. From the viewpoint of practicality, it is preferably at least one selected from the group consisting of cellulose unwoven cloth, polypropylene, polyethylene and PET, and more preferably cellulose unwoven cloth.
- the area ratio between the separator and the negative electrode used in the nonaqueous electrolyte secondary battery of the present invention is not particularly limited, but preferably satisfies the following formula (3).
- G represents the area of the negative electrode
- H represents the area of the separator.
- the thickness of the separator is preferably 10 ⁇ m or more and 100 ⁇ m or less. If the thickness is less than 10 ⁇ m, the positive electrode and the negative electrode may be in direct contact with each other. If the thickness is greater than 100 ⁇ m, the internal resistance of the battery may be increased. From the viewpoint of economy and handling, the thickness of the separator is more preferably 15 ⁇ m or more and 50 ⁇ m or less.
- Non-aqueous electrolyte> The amount of the non-aqueous electrolyte contained in the encapsulated body of the non-aqueous electrolyte secondary battery of the present invention is not particularly limited, but a viewpoint of expressing desired battery performance by sufficiently ensuring the lithium ion conduction accompanying the electrode reaction. Therefore, it is preferably 1.0 mL or more per 1 Ah of battery capacity.
- the nonaqueous electrolyte may be included in the positive electrode, the negative electrode and the separator in advance, or may be added to an electrode group obtained by winding or laminating a separator disposed between the positive electrode side and the negative electrode side. Good.
- nonaqueous electrolyte according to the present invention is not particularly limited, an electrolyte solution in which a solute is dissolved in a nonaqueous solvent, a gel electrolyte in which a polymer is impregnated with an electrolyte solution in which a solute is dissolved in a nonaqueous solvent, or the like is used. Can do.
- the nonaqueous electrolyte according to the present invention may contain a trace amount of additives such as a flame retardant and a stabilizer.
- the non-aqueous solvent is preferably an aprotic solvent because the solvent is unlikely to decompose at the operating potential of the non-aqueous electrolyte secondary battery, more preferably an aprotic solvent containing an aprotic polar solvent, More preferably, the aprotic polar solvent is at least one selected from the group consisting of a cyclic aprotic solvent and a chain aprotic solvent, and the particularly preferred nonaqueous solvent is a cyclic aprotic polarity.
- a non-aqueous solvent consisting of a solvent and a chain aprotic polar solvent.
- cyclic aprotic polar solvent examples include cyclic carbonates, cyclic esters, cyclic sulfones and cyclic ethers.
- cyclic carbonate examples include ethylene carbonate, propylene carbonate, fluoroethylene carbonate, butylene carbonate and the like.
- chain aprotic polar solvent examples include acetonitrile, chain carbonate, chain carboxylic acid ester, chain ether, and the like.
- chain carbonate examples include dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate.
- hydrocarbons such as hexane and benzene are exemplified.
- dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethylene carbonate, fluoroethylene carbonate, propylene carbonate, butylene carbonate, ⁇ -butyl lactone, 1,2-dimethoxyethane, Sulfolane, dioxolane, methyl propionate and the like can be used.
- These solvents may be used singly or in combination of two or more, but can improve the solubility of the solute which is a supporting salt described later, and can improve the conductivity of lithium ions. Since it can raise, it is preferable to use the solvent which mixed 2 or more types.
- a gel electrolyte in which an electrolyte is impregnated in a polymer can also be used.
- the solute is not particularly limited.
- LiClO 4 , LiBF 4 , LiPF 6 , LiAsF 6 , LiCF 3 SO 3 , LiBOB (Lithium Bis (Oxalato) Borate), LiN (SO 2 CF 3 ) 2, and the like are non-aqueous.
- LiPF 6 is preferable because it is easily dissolved in a solvent, and LiPF 6 is more preferable.
- the concentration of the solute contained in the electrolytic solution is preferably 0.5 mol / L or more and 2.0 mol / L or less. If it is less than 0.5 mol / L, the desired lithium ion conductivity may not be exhibited. On the other hand, if it is higher than 2.0 mol / L, the solute may not be dissolved any more.
- first positive electrode active material of the first positive electrode a commercial product of powder of the following material, which is a layered rock salt type compound, was used, and the positive electrode A, positive electrode A +, positive electrode B, and positive electrode C were used as the first positive electrode in the following manner. Each of was made.
- Positive electrode A positive electrode A +: LiCoO 2
- Positive electrode B LiNi 1/3 Mn 1/3 Co 1/3 O 2
- Positive electrode C LiNi 0.8 Co 0.15 Al 0.05 O 2
- 100 parts by weight of each of these powders, 5 parts by weight of a conductive additive (acetylene black), and 5 parts by weight of a binder (polyvinylidene fluoride, solid concentration 8 wt%, NMP solution) are mixed to prepare these materials.
- a slurry of the mixture was prepared.
- this coating was carried out on both sides of the aluminum foil to make a single-sided electrode and on both sides of the aluminum foil to make a double-sided electrode, thereby producing both electrodes.
- the capacity of the positive electrode A was made larger than that of the positive electrode A by adjusting the clearance of the coating machine in the manufacture of the positive electrode A.
- Li 1.1 Al 0.1 Mn 1.8 O 4 powder was prepared by the method described in the literature (Electrochemical and Solid-State Letters, 9 (12), A557 (2006)). That is, an aqueous dispersion of manganese dioxide, lithium carbonate, aluminum hydroxide, and boric acid was prepared, and a mixed powder was prepared by a spray drying method. At this time, the amounts of manganese dioxide, lithium carbonate and aluminum hydroxide were adjusted so that the molar ratio of lithium, aluminum and manganese was 1.1: 0.1: 1.8. Next, the mixed powder was heated at 900 ° C. for 12 hours in an air atmosphere, and then again heated at 650 ° C. for 24 hours. Finally, the powder was washed with water at 95 ° C. and then dried to prepare a powder of Li 1.1 Al 0.1 Mn 1.8 O 4 .
- Second positive electrode E Using a powder of LiNi 0.5 Mn 1.5 O 4 which is spinel type lithium manganate as a positive electrode active material of the second positive electrode, a high voltage positive electrode is used as the second positive electrode by the following method. A positive electrode E was produced.
- Positive electrode E LiNi 0.5 Mn 1.5 O 4
- the powder of LiNi 0.5 Mn 1.5 O 4 the literature ( "Solid-state redox potentials for Li [Me 1/2 Mn 3/2] O4 (Me: 3d-transition metal) having spinel-framework structures : A series of 5 volt materials for advanced lithium-ion batteries "Journal of Power Sources, Vol. 81-82, pp. 90-94 (1999)).
- lithium hydroxide, manganese hydroxide, and nickel hydroxide were first mixed so that the molar ratio of lithium, manganese, and nickel was 1: 1.5: 0.5. Next, this mixture was heated at 550 ° C. in an air atmosphere, and then heated again at 750 ° C. to prepare a LiNi 0.5 Mn 1.5 O 4 powder.
- each positive electrode as a single-sided electrode was punched into a working electrode of 16 mm ⁇ , and a Li metal plate was punched out into a 16 mm ⁇ as a counter electrode.
- the working electrode the coated surface of single-sided coating was inside
- separator / counter electrode Li metal plate
- a half battery was prepared by adding 0.15 mL.
- the value of the end voltage in the constant current charge was set to the following value for each positive electrode, and the value of the end voltage in the constant current discharge was set to 3.0V.
- Positive electrode A positive electrode A + (LiCoO 2 ): 4.25V
- Positive electrode B (LiNi 1/3 Mn 1/3 Co 1/3 O 2 ): 4.25V
- the positive electrode C (LiNi 0.8 Co 0.15 Al 0.05 O 2): 4.25V
- Positive electrode D (Li 1.1 Al 0.1 Mn 1.8 O 4 ): 4.5 V
- Positive electrode E (LiNi 0.5 Mn 1.5 O 4 ): 5.0 V
- the capacity per unit area of each positive electrode was the value described below.
- Positive electrode A (LiCoO 2 ): 1.0 mAh / cm 2 Positive electrode A + (LiCoO 2 ): 1.6 mAh / cm 2 Positive electrode B (LiNi 1/3 Mn 1/3 Co 1/3 O 2 ): 1.0 mAh / cm 2 Positive electrode C (LiNi 0.8 Co 0.15 Al 0.05 O 2 ): 1.0 mAh / cm 2 Positive electrode D (Li 1.1 Al 0.1 Mn 1.8 O 4 ): 1.6 mAh / cm 2 Positive electrode E (LiNi 0.5 Mn 1.5 O 4 ): 1.6 mAh / cm 2
- a negative electrode F was produced by the following method using a powder of Li 4 Ti 5 O 12 which is lithium titanate as a negative electrode active material.
- Negative electrode F Li 4 Ti 5 O 12
- Li 4 Ti 5 O 12 powder is obtained from the literature (“Zero-Strain Insertion Material of Li [Li 1/3 Ti 5/3 ] O 4 for Rechargeable Lithium Cells” Journal of Electrochemical Society, 142, 1431 (1995). ). That is, titanium dioxide and lithium hydroxide are mixed so that the molar ratio of titanium and lithium is 5: 4, and then this mixture is heated at 800 ° C. for 12 hours in a nitrogen atmosphere to thereby form Li 4 Ti 5 O. 12 powders were prepared.
- the slurry was applied to an aluminum foil (15 ⁇ m), and then vacuum-dried at 170 ° C., thereby producing a negative electrode F using Li 4 Ti 5 O 12 as a negative electrode active material. Both single-sided and double-sided electrodes were made.
- a negative electrode G was produced by the following method using a powder of TiO 2 (B), which is bronze-type titanium dioxide, as the negative electrode active material.
- TiO 2 (B) powder was prepared by the method described in the literature (Journal of Electrochemical Society, 159, A 49-A54 (2012)). That is, first, titanium dioxide and potassium carbonate are mixed so as to have a molar ratio of 4: 1, and then this mixture is heated twice in the atmosphere at 1000 ° C. for 24 hours, whereby K 2 Ti 4 O 9 was obtained. H 2 Ti 4 O 9 obtained by treating this K 2 Ti 4 O 9 with a 1.0 M aqueous hydrochloric acid solution was heated at 500 ° C. in an air atmosphere for 0.5 hours to obtain TiO 2 (B) A powder was prepared.
- a negative electrode G was produced by the following method using a powder of H 2 Ti 12 O 25 which is a titanic acid compound as a negative electrode active material.
- H 2 Ti 12 O 25 powder was prepared by the method described in the literature (Journal of Electrochemical Society, 158, A546-A549 (2011)). That is, first, titanium dioxide and sodium carbonate are mixed so that the molar ratio is 3: 1, and then this mixture is heated twice in the atmosphere at 800 ° C. for 20 hours to thereby form Na 2 Ti. 3 O 7 was obtained. H 2 Ti 3 O 7 obtained by treating this Na 2 Ti 3 O 7 with a 0.5 M aqueous hydrochloric acid solution was heated at 260 ° C. for 5 hours in an air atmosphere to produce H 2 Ti 12 O 25 powder. Was made.
- a slurry is prepared in the same manner as described in the above (Preparation of negative electrode F), and further, coating and vacuum drying are performed to prepare a negative electrode H. did.
- Capacitance measurement of negative electrodes F to H The capacity of each negative electrode thus produced was measured by the same method as described in the above (Capacitance measurement of positive electrodes A to E). The current value in constant current charging and constant current discharging is 0.4 mA as described in the above (capacitance measurement of positive electrodes A to E).
- the capacity per unit area of each negative electrode was the value described below.
- Negative electrode F Li 4 Ti 5 O 12 : 1.7 mAh / cm 2
- Negative electrode G TiO 2 (B): 1.7 mAh / cm 2
- Negative electrode H H 2 Ti 12 O 25 ): 1.7 mAh / cm 2
- the charge / discharge cycle test was first performed from the charge under the following cycle conditions, and the discharge and charge were repeated under the following charge condition 1 and discharge condition 1 and finally discharged.
- the voltage described below is not based on lithium, but is a voltage of a nonaqueous electrolyte secondary battery.
- Charging condition 1 With respect to the total capacity of the second positive electrode, the battery is charged with a constant current of 1.0 C until the voltage reaches 2.7 V, and then charged with a constant voltage while maintaining 2.7 V. When the current reaches 0.02C, the charging is finished.
- Discharge condition 1 Discharge at a constant current of 1.0 C until the voltage decreases to 2.0 V with respect to the total capacity of the second positive electrode, and when the voltage reaches 2.0 V, the discharge ends.
- the capacity retention rate is a percentage value when the discharge capacity after 400 cycles of charge / discharge under a predetermined condition to be described later is compared with the discharge capacity at the first cycle.
- the amount of gas generated is preliminarily provided in the aluminum laminate sheet that is the exterior of the battery enclosure as a part of the volume of the enclosure, and the gas generated during the charge / discharge cycle is stored in this gas pocket.
- the volume of the battery before and after the charge / discharge cycle test was determined by measuring by the Archimedes method.
- the batteries of Examples 1 to 7 all passed, and the batteries of Comparative Examples 1 and 2 all failed.
- the batteries of Examples 1 to 6 are excellent batteries because the capacity retention rate is as high as 88% or more and the amount of gas after cycling is as low as 1.0 mL / Ah or less.
- the first positive electrode does not contain a layered rock salt type compound having a gas suppressing effect as a positive electrode active material, there is no gas suppressing effect, and gas is generated, so that the internal resistance is low.
- the capacity maintenance rate is low.
- the battery of Example 7 uses the positive electrode E (LiNi 0.5 Mn 1.5 O 4 ), which can be charged and discharged at a higher voltage than the batteries of the other examples, as the high-voltage positive electrode. Nevertheless, since the amount of gas is small and the capacity retention rate is high, it can be expected to be used in applications that require high voltage. Furthermore, although the amount of gas in the battery of Example 7 is larger than that of the batteries of Examples 1 to 6, this is considered to be due to the presence of gas generated at the positive electrode in addition to the gas generated at the negative electrode.
- Example 1 A battery of Example 1 was prepared using positive electrode A as the first electrode, positive electrode D as the second positive electrode, and negative electrode F as the negative electrode.
- the separator used for preparation is a cellulose unwoven cloth (25 ⁇ m, 30 cm 2 ).
- the prepared positive electrode and negative electrode were laminated in the order of the second positive electrode / separator / negative electrode, thereby preparing an electrode group corresponding to 1 Ah in terms of positive electrode capacity.
- a separator is further laminated on the uppermost second positive electrode as viewed from the lamination direction of this electrode group, and further, negative electrode / separator / first positive electrode / separator / negative electrode are laminated thereon.
- An electrode group was prepared.
- FIG. 2 shows a conceptual diagram of this electrode group as a conceptual diagram of one embodiment of the electrode group according to the present invention.
- one first positive electrode is vibration welded to one first positive terminal, 13 second positive electrodes to one second positive terminal, and 15 negative electrodes to one negative terminal. And the electrode group provided with a terminal was produced.
- FIG. 3 is an external conceptual view of another embodiment of the nonaqueous electrolyte secondary battery 10 of the present invention. This battery was cured by leaving it for 12 hours.
- the extension portions of the first positive electrode terminal and the negative electrode terminal of the battery after curing are respectively connected to the two terminals of the charge / discharge device, and the amount of electricity necessary for the first positive electrode to be 100% SOC. On the other hand, it was charged to SOC 100% at a constant current of 0.2C. Thereafter, the extending portion of the first positive electrode terminal was electrically insulated from the surroundings by covering with a polyimide tape.
- the first positive electrode was electrically insulated while being kept in a constant charge state, and the second positive electrode and the negative electrode By repeating charging / discharging using the gas, it is possible to achieve gas suppression even when a titanium compound is used as the negative electrode active material without causing deterioration of the first positive electrode.
- the battery of the present invention has the first positive electrode as a natural function of the positive electrode. Since there is a period in which the battery is in a charged state during charging / discharging due to the use of the battery, the effect of suppressing gas generation, which is the effect of the present invention, appears remarkably, and the increase in internal resistance due to gas generation does not occur.
- Example 2 A battery of Example 2 was made in the same manner as Example 1 except that the positive electrode B was used as the first positive electrode.
- the produced battery of Example 2 was subjected to a charge / discharge cycle test under charge condition 1 and discharge condition 1 while maintaining the state of charge of the first positive electrode at 100%. The test results are shown in Table 1.
- Example 4 A battery of Example 4 was made in the same manner as Example 1 except that the positive electrode A + having a capacity of 1.6 mAh / cm 2 was used as the first positive electrode.
- the first positive electrode and the second positive electrode were connected to the same positive electrode terminal, and the charge / discharge cycle test of charge condition 1 and discharge condition 1 was performed using the positive electrode terminal and the negative electrode terminal. did.
- the test results are shown in Tables 1 and 2. Therefore, for the battery of Example 4, the first positive electrode is not charged to a predetermined charge state in advance, and the same potential as the second positive electrode is maintained during the charge / discharge cycle test. Charging / discharging was repeated.
- both the first positive electrode and the second positive electrode are batteries.
- the gas suppression effect is maintained, but the capacity deterioration of the first positive electrode due to charging / discharging cannot be suppressed, and the capacity retention rate is slightly low although it satisfies the acceptance criteria. It became.
- Example 5 A battery of Example 5 was made in the same manner as Example 1 except that the negative electrode G was used as the negative electrode.
- the manufactured battery of Example 5 was subjected to a charge / discharge cycle test under charge condition 1 and discharge condition 1 while maintaining the state of charge of the first positive electrode at 90%. The test results are shown in Table 1.
- Example 6 A battery of Example 6 was made in the same manner as Example 1 except that the negative electrode H was used as the negative electrode.
- the charge state of the first positive electrode was maintained at 90%, and charge / discharge cycles of charge condition 1 and discharge condition 1 were performed.
- the test results are shown in Table 1.
- Example 7 A battery was fabricated in the same manner as in Example 1 except that the high-voltage positive electrode E was used as the second positive electrode. About the produced battery of Example 7, the charge state of the first positive electrode was maintained at 90%, and the charge / discharge cycle test was performed at 25 ° C. instead of 60 ° C., and the charge / discharge The test was carried out in the same manner as described above (method of charge / discharge cycle test) except that the condition was not the charge condition 1 but the charge condition 2 described below. The test results are shown in Table 1.
- Charging condition 2 With respect to the total capacity of the second positive electrode, charging is performed at a constant current of 1.0 C until the voltage reaches 3.4 V, and then the charging is terminated when the voltage reaches 3.4 V. .
- Comparative Example 1 A battery of Comparative Example 1 was produced in the same manner as Example 1 except that the positive electrode D was used as the first positive electrode. About the produced battery of the comparative example 1, the charging / discharging cycle test of the charge condition 1 and the discharge condition 1 was implemented, maintaining the charge condition of the 1st positive electrode at 100%. The test results are shown in Table 1.
- Example 2 A battery was prepared and evaluated in the same manner as in Example 7 except that the positive electrode E was used as the first positive electrode.
Abstract
Description
一方の前記正極とこれと隣り合う他方の前記正極との間に、2つの前記セパレータで挟持された前記負極であるセパレータ挟持負極を備え、かつ、
前記複数の種類の正極は、層状岩塩型化合物を正極活物質(以下、「第一の正極活物質」と称することがある。)として含む第一の正極と、前記層状岩塩型化合物とは異なる種類の正極活物質(以下、「第二の正極活物質」と称することがある。)を主成分とする第二の正極とを含むことを特徴とする非水電解質二次電池に関する。
本発明の非水電解質二次電池10は、複数の種類の正極2と、非水電解質と、負極1と、正極2と負極1との間に挟持された電気絶縁材料からなるセパレータ3と、が封入された封入体8を有する。このような本発明に係る封入体8内において、正極2、負極1、及びセパレータ3の少なくとも表面や、その内部には、リチウムイオン伝導を担う本発明に係る非水電解質が存在する。
本発明の電池は、通常の充放電の用に供される第二の正極以外に、本発明のガス発生抑制効果を得る為に、第一の正極を有する。この本発明に係る第一の正極は、特定の活物質、具体的には、層状岩塩型化合物を含む。なお、以下の記載においては、各構成部材の参照符号を省略する場合がある。
本発明の非水電解質二次電池は、本発明に係る封入体を複数有することができ、その場合には、各封入体の負極端子71を直列又は並列に、かつ、第二正極端子72-2を直列又は並列(負極端子71を直列に接続する場合は第二正極端子72-2も直列に接続し、負極端子71を並列に接続する場合は第二正極端子72-2も並列に接続することが好ましい。)に、各々接続して、電池そのものの2つの端子として、電池負極端子および電池正極端子を備える非水電解質二次電池とすることが好ましく、その場合でも、各封入体の第一正極端子72-1は接続することなく、周囲環境からの絶縁を維持することがより好ましい。
本発明に係る正極および負極は、電極反応に寄与する各極の活物質が存在する部分であり、この部分を含む部材を、例えば後述する集電体や端子を含んで、正極部材又は負極部材と呼称することとするが、本明細書において、正極および負極とは、この部材ではなく、各極の活物質が存在する部分のことを指す。
本発明に係る正極及び負極は、集電体に活物質を含む材料の層を形成したものであることが好ましく、高性能かつコンパクトな電池とするために、この集電体の両面には、同じ極となるような材料層が形成されていることがより好ましい。
前記材料層を構成する材料としては、少なくとも各極の活物質を含み、この他に、この活物質層の性能向上のために、導電助材やバインダーが含まれてもよい。これらの材料を含む混合物を集電体上に材料層として形成することによって正極又は負極とすることが好ましい。
各極の活物質は、一般に粉体として供給されている。
本発明に係る正極の材料層の材料は、電子導電性に乏しいことから導電助材を含有することを要する。
本発明に係る正極、又は負極の材料層は、各々の活物質を集電体に結着させるために、バインダーを含むことが好ましい。
本発明に係る負極は、本発明の電池の充電時に、電解質からリチウムイオンを受け入れ、かつ、負極端子を介して電子を受け取る機能を有し、また、本発明の電池の放電時に、電解質にリチウムイオンを放出し、かつ、負極端子を介して電子を供給する機能を有する。このような負極は、集電体上に、少なくとも活物質(以下、「負極活物質」と称することがある。)が含まれる材料層(以下、「負極活物質層」と称することがある。)が形成されている部材として作製することが好ましく、このような負極部材の一部が、本発明に係る封入体に封入されると共に、その一部が封入体の外側に負極端子延在部として引き出されることで、外部機器と電気接続される。
本発明に係る負極活物質としては、チタン化合物を主成分すること、即ち、全負極活物質に対してチタン化合物が50質量%を超える成分として含まれていることを要し、チタン化合物以外の負極活物質材料として、50質量%を下回る割合で、Nbなどのリチウム、チタン以外の元素が含まれていても良く、チタン化合物を80質量%以上含み、かつ、チタン化合物以外の負極活物質材料を20質量%以下含むことが好ましく、さらに好ましくはNbなどのリチウム、チタン以外の元素が微量含まれていても良いチタン化合物とすることである。
本発明に係る正極は、本発明の電池の充電時に、電解質へリチウムイオンを放出し、かつ、正極端子を介して電子を供給する機能を有し、また、本発明の電池の放電時に、電解質からリチウムイオンを受け入れ、かつ、正極端子を介して電子を受け取る機能を有する。このような正極は、集電体上に、少なくとも活物質(以下、「正極極活物質」と称することがある。)が含まれる材料層(以下、「正極活物質層」と称することがある。)が形成されている部材として作製することが好ましく、このような正極部材の一部が、本発明に係る封入体に封入されると共に、その一部が封入体の外側に正極端子延在部として引き出されることで、外部機器と電気接続される。
本発明において、ガス発生抑制効果を発現する電極は、層状岩塩型活物質を有する第一の正極である。ガス抑制のメカニズムは明確ではないが層状岩塩型活物質はガスを吸蔵する効果があり、特に、充電状態を維持している場合に、より高いガス抑制効果を有すると考えられる。
本発明に係る正極の内、本発明の電池の目的である通常の充放電に供される正極は、第二の正極である。従って、第二の正極の正極活物質として用いる材料としては、通常の充放電において、材料の膨張および収縮が少なく、材料劣化が起こりにくい材料であることが長期に亘って信頼性が高い寿命の長い電池とする観点から好ましい。
本発明に係るセパレータは、前述の正極と負極との間に設置され、これらの間の電子やホールの伝導を阻止しつつ、これらの間のリチウムイオンの伝導を仲介する媒体としての機能(リチウムイオン透過性)を有し、少なくとも電子やホールの伝導性を有さない電気絶縁性のものであれば、各種可塑剤、化防止剤、難燃剤が含まれてもよいし、金属酸化物等によって被覆されていてもよい。その材料としては、電気絶縁材料からなるものであることを要し、少なくとも108Ω・cm以上の比抵抗の材料のみから構成されていることが好ましく、例えば、ナイロン、セルロース、ポリスルホン、ポリエチレン、ポリプロピレン、ポリブテン、ポリアクリロニトリル、ポリイミド、ポリアミド、PET及びそれらを2種類以上複合したものの織布、不織布、微多孔膜などが挙げられる。実用性の観点から、セルロース不職布、ポリプロピレン、ポリエチレン及びPETからなる群から選ばれる1種以上であることが好ましく、より好ましくは、セルロース不職布である。
が、下記式(3)を満たすことが好ましい。
本発明の非水電解質二次電池の封入体内に含まれる非水電解質の量は、特に限定されないが、電極反応に伴うリチウムイオンの伝導を十分に担保せしめることで所望の電池性能を発現させる観点から、電池容量1Ahあたり、1.0mL以上であることが好ましい。
前記非水溶剤としては、非水電解質二次電池の作動電位において溶剤の分解が起こりにくいことから非プロトン性溶剤が好ましく、非プロトン性極性溶剤を含む非プロトン性溶剤であることがより好ましく、前記非プロトン性極性溶剤が環状の非プロトン性溶剤および鎖状の非プロトン性溶剤からなる群から選ばれる1種以上であることがさらに好ましく、特に好ましい前記非水溶剤は、環状非プロトン性極性溶剤および鎖状非プロトン性極性溶剤からなる非水溶剤とすることである。
溶質は、特に限定されないが、例えば、LiClO4、LiBF4、LiPF6、LiAsF6、LiCF3SO3、LiBOB(Lithium Bis(Oxalato)Borate)、LiN(SO2CF3)2などが前記非水溶媒に溶解しやすいことから好ましく、より好ましくはLiPF6である。
第一の正極の正極活物質として、層状岩塩型化合物である以下の材料の粉末の市販品を用いて、以下の方法で、第一の正極として、正極A、正極A+、正極B、正極Cの各々を作製した。
正極B:LiNi1/3Mn1/3Co1/3O2
正極C:LiNi0.8Co0.15Al0.05O2
まず、これらの粉末の各々を100重量部、導電助材(アセチレンブラック)を5重量部、およびバインダー(ポリフッ化ビニリデン、固形分濃度8wt%、NMP溶液)を5重量部混合してこれらの材料の混合物のスラリーを作製した。
第二の正極の正極活物質として、スピネル型マンガン酸リチウムであるLi1.1Al0.1Mn1.8O4の粉末を用いて、以下の方法で、第二の正極として、正極Dを作製した。
まず、Li1.1Al0.1Mn1.8O4の粉末を、文献(Electrochemical and Solid-State Letters、9(12)、A557(2006))に記載されている方法で作製した。すなわち、二酸化マンガン、炭酸リチウム、水酸化アルミニウム、およびホウ酸の水分散液を調製し、スプレードライ法で混合粉末を作製した。このとき、二酸化マンガン、炭酸リチウムおよび水酸化アルミニウムの量は、リチウム、アルミニウムおよびマンガンのモル比が1.1:0.1:1.8となるように調整した。次に、この混合粉末を空気雰囲気下900℃で12時間加熱した後、再度650℃で24時間加熱した。最後に、この粉末を95℃の水で洗浄後、乾燥させることによってLi1.1Al0.1Mn1.8O4の粉末を作製した。
第二の正極の正極活物質として、スピネル型マンガン酸リチウムであるLiNi0.5Mn1.5O4の粉末を用いて、以下の方法で、第二の正極として、高電圧系正極である正極Eを作製した。
まず、LiNi0.5Mn1.5O4の粉末を、文献("Solid-state redox potentials for Li[Me1/2Mn3/2]O4(Me:3d-transition metal)having spinel-framework structures:
a series of 5 volt materials for advanced lithium-ion batteries "Journal of Power Sources, Vol. 81-82, pp.90-94(1999))に記載されている方法で作製した。
このようにして作製した各正極の容量を、以下の方法で、各正極を動作極、Li電極を対極とする半電池の充放電試験を実施することにより、測定した。以下に記載する電圧値は、全てリチウム電極を基準とする値である。
正極B(LiNi1/3Mn1/3Co1/3O2):4.25V
正極C(LiNi0.8Co0.15Al0.05O2):4.25V
正極D(Li1.1Al0.1Mn1.8O4):4.5V
正極E(LiNi0.5Mn1.5O4):5.0V
各正極の単位面積当たりの容量は、以下に記載の値であった。
正極A+(LiCoO2):1.6mAh/cm2
正極B(LiNi1/3Mn1/3Co1/3O2):1.0mAh/cm2
正極C(LiNi0.8Co0.15Al0.05O2):1.0mAh/cm2
正極D(Li1.1Al0.1Mn1.8O4):1.6mAh/cm2
正極E(LiNi0.5Mn1.5O4):1.6mAh/cm2
負極活物質として、チタン酸リチウムであるLi4Ti5O12の粉末を用いて、以下の方法で、負極Fを作製した。
まず、Li4Ti5O12の粉末を、文献("Zero-Strain Insertion Material of Li [Li1/3Ti5/3]O4for Rechargeable Lithium Cells" Journal of Electrochemical Society、142、1431(1995))に記載されている方法で作製した。すなわち、二酸化チタンと水酸化リチウムを、チタンとリチウムとのモル比を5:4となるように混合し、次にこの混合物を窒素雰囲気下800℃で12時間加熱することによってLi4Ti5O12の粉末を作製した。
負極活物質として、ブロンズ型二酸化チタンであるTiO2(B)の粉末を用いて、以下の方法で、負極Gを作製した。
まず、TiO2(B)の粉末を、文献(Journal of Electrochemical Society、159、A 49-A54(2012))に記載されている方法で作製した。すなわち、まず二酸化チタンと炭酸カリウムとを、モル比が4:1となるように混合し、次にこの混合物を、大気中1000℃の24時間加熱を二度実施することによって、K2Ti4O9を得た。このK2Ti4O9を1.0Mの塩酸水溶液で処理することで得られたH2Ti4O9を、空気雰囲気下500℃で0.5時間加熱することによってTiO2(B)の粉末を作製した。
負極活物質として、チタン酸化合物であるH2Ti12O25の粉末を用いて、以下の方法で、負極Gを作製した。
まず、H2Ti12O25の粉末を、文献(Journal of Electrochemical Society、158、A546-A549(2011))に記載されている方法で作製した。すなわち、まず二酸化チタンと炭酸ナトリウムとを、モル比が3:1となるように混合し、次にこの混合物を、大気中で800℃の20時間加熱を二度実施することによって、Na2Ti3O7を得た。このNa2Ti3O7を0.5Mの塩酸水溶液で処理することで得られたH2Ti3O7を、空気雰囲気下260℃で5時間加熱することによってH2Ti12O25の粉末を作製した。
このようにして作製した各負極の容量を、上述の(正極A~Eの容量測定)に記載したのと同様の方法で測定した。定電流充電および定電流放電における電流値も、上述の(正極A~Eの容量測定)に記載したのと同様、0.4mAである。
負極G(TiO2(B)):1.7mAh/cm2
負極H(H2Ti12O25):1.7mAh/cm2
上述のようにして作製し準備した両面電極を用い実施例1~7と、比較例1及び2の電池を、以下の(実施例1)等に記載の方法で作製し、作製した電池について、以下に記載の方法で充放電サイクル試験を実施した後の、容量維持率(%)およびサイクル中に発生した単位容量当たりのガス発生量(mL/Ah)を、以下に記載の方法で測定し評価した。
充放電サイクル試験は、下記サイクル条件で、最初に充電から実施し、放電および充電を下記充電条件1および放電条件1にて繰り返し、最後に放電することで実施した。以下に記載する電圧は、リチウム基準ではなく、非水電解質二次電池の電圧である。
電池環境温度:60℃
単位サイクル:充電1回及び放電1回を1サイクルとする。
繰り返しサイクル数:400サイクル
充電条件1:第二の正極の総容量に対して、電圧が2.7Vに達するまでは1.0Cの定電流で充電し、その後、2.7Vを維持して定電圧で充電し、その後、電流が0.02Cとなった時点で充電を終了する。
なお、容量維持率とは、後述する所定の条件での充放電を400サイクル実施した後の放電容量を、1サイクル目の放電容量と比較した時のパーセント値である。
第一の電極として正極Aを、第二の正極として正極Dを、負極として負極Fを用い実施例1の電池を作製した。作製に使用したセパレータは、セルロース不職布(25μm、30cm2)である。
第一の正極として正極Bを用いたこと以外は、実施例1と同様にして実施例2の電池を作製した。作製した実施例2の電池について、その第一の正極の充電状態を100%に維持しつつ、充電条件1および放電条件1の充放電サイクル試験を実施した。試験結果を表1に示す。
第一の正極として正極Cを用いたこと以外は、実施例1と同様にして実施例3の電池を作製した。作製した実施例3の電池について、その第一の正極の充電状態を100%に維持しつつ、充電条件1および放電条件1の充放電サイクル試験を実施した。試験結果を表1に示す。
第一の正極として、その容量が1.6mAh/cm2である正極A+を用いたこと以外は、実施例1と同様にして実施例4の電池を作製した。作製した実施例4の電池について、第一の正極および第二の正極を同一の正極端子に接続し、正極端子および負極端子を用いて、充電条件1および放電条件1の充放電サイクル試験を実施した。試験結果を表1および2に示す。従って、この実施例4の電池については、その第一の正極を、予め所定の充電状態まで充電することはせず、充放電サイクル試験中、第二の正極と同電位の状態を維持しつつ充放電を繰り返したこととなる。
負極として負極Gを用いたこと以外は、実施例1と同様にして実施例5の電池を作製した。作製した実施例5の電池について、その第一の正極の充電状態を90%に維持しつつ、充電条件1および放電条件1の充放電サイクル試験を実施した。試験結果を表1に示す。
負極として負極Hを用いたこと以外は、実施例1と同様にして実施例6の電池を作製した。作製した実施例6の電池について、その第一の正極の充電状態を90%に維持し、充電条件1および放電条件1の充放電サイクルを実施した。試験結果を表1に示す。
第二の正極として高電圧系正極Eを用いたこと以外は、実施例1と同様に電池を作製した。作製した実施例7の電池について、その第一の正極の充電状態を90%に維持し、充放電サイクル試験を、その環境温度環境を60℃ではなく25℃としたこと、および、その充放電条件を、充電条件1ではなく、以下に記載する充電条件2としたこと以外は、上述の(充放電サイクル試験の方法)と同様にして、実施した。試験結果を表1に示す。
第一の正極として正極Dを用いたこと以外は、実施例1と同様にして比較例1の電池を作製した。作製した比較例1の電池について、その第一の正極の充電状態を100%に維持しつつ、充電条件1および放電条件1の充放電サイクル試験を実施した。試験結果を表1に示す。
第一の正極として正極Eを用いたこと以外は、実施例7と同様に電池を作製し評価した。
2 正極
3 セパレータ
7 端子
8 封入体
9 端子延在部
10 非水電解質二次電池
21 第一の正極
22 第二の正極
31 セパレータ挟持負極
71 負極端子
72 正極端子
72-1 第一正極端子
72-2 第二正極端子
100 組電池
Claims (8)
- 正極活物質を有する複数の種類の正極と、非水電解質と、チタン化合物を負極活物質の主成分とする負極と、正極と負極との間に挟持された電気絶縁材料からなるセパレータと、が封入されてなる封入体を有する非水電解質二次電池であって、
一方の前記正極とこれと隣り合う他方の前記正極との間に、2つの前記セパレータで挟持された前記負極であるセパレータ挟持負極を備え、かつ、
前記複数の種類の正極は、層状岩塩型化合物を正極活物質として含む第一の正極と、前記層状岩塩型化合物とは異なる種類の正極活物質を主成分とする第二の正極とを含むことを特徴とする非水電解質二次電池。 - 全ての前記正極の両側に、前記セパレータ挟持負極を備えることを特徴とする請求項1に記載の非水電解質二次電池。
- 前記第一の正極は、前記非水電解質二次電池の放電時に、自然放電を除き、少なくとも外部負荷の接続によっては放電されず、一定の充電状態を保ったまま、前記封入体内に維持されることを特徴とする請求項1、又は2に記載の非水電解質二次電池。
- さらに、前記第一の正極、前記第二の正極及び前記負極の各々に接続されている端子であって、前記封入体の外側に延在する端子延在部を有する前記端子を含み、
前記第一の正極の前記正極端子延在部が、前記第二の正極の前記正極端子延在部とは別に存在することを特徴とする請求項1~3のいずれか1項に記載の非水電解質二次電池。 - 前記チタン化合物が、Li4Ti5O12、H2Ti12O25、及びTiO2で表されるチタン化合物からなる群から選ばれる1種以上である、請求項1~4のいずれか1項に記載の非水電解質二次電池。
- 前記層状岩塩型化合物が、コバルト酸リチウム、コバルトニッケルアルミニウム酸リチウム、及びコバルトニッケルマンガン酸リチウムからなる群から選ばれる1種以上の層状岩塩型化合物である、請求項1~5のいずれか1項に記載の非水電解質二次電池。
- 前記層状岩塩型化合物とは異なる種類の正極活物質が、スピネル型マンガン酸リチウムである、請求項1~6のいずれか1項に記載の非水電解質二次電池。
- 請求項1~7のいずれか1項に記載の非水電解質二次電池を複数個接続してなる組電池。
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2016529613A JP6581981B2 (ja) | 2014-06-24 | 2015-06-23 | 非水電解質二次電池およびこれを複数個接続してなる組電池 |
CN201580034353.6A CN106463780B (zh) | 2014-06-24 | 2015-06-23 | 非水电解质二次电池、以及将多个该非水电解质二次电池连接而成的组电池 |
US15/320,678 US10516162B2 (en) | 2014-06-24 | 2015-06-23 | Non-aqueous electrolyte secondary battery, and battery pack obtained by connecting plurality of non-aqueous electrolyte secondary batteries |
EP15812730.8A EP3163667B1 (en) | 2014-06-24 | 2015-06-23 | Non-aqueous electrolyte secondary battery, and battery pack obtained by connecting plurality of non-aqueous electrolyte secondary batteries |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2014-129582 | 2014-06-24 | ||
JP2014129582 | 2014-06-24 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2015199101A1 true WO2015199101A1 (ja) | 2015-12-30 |
Family
ID=54938181
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2015/068102 WO2015199101A1 (ja) | 2014-06-24 | 2015-06-23 | 非水電解質二次電池およびこれを複数個接続してなる組電池 |
Country Status (5)
Country | Link |
---|---|
US (1) | US10516162B2 (ja) |
EP (1) | EP3163667B1 (ja) |
JP (1) | JP6581981B2 (ja) |
CN (1) | CN106463780B (ja) |
WO (1) | WO2015199101A1 (ja) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2017078108A1 (ja) * | 2015-11-06 | 2017-05-11 | 日立化成株式会社 | リチウムイオン二次電池 |
DE102017202995A1 (de) | 2017-02-24 | 2018-08-30 | Robert Bosch Gmbh | Elektrische Energiespeichereinheit mit mindestens einer elektrisch isolierten Elektrodenmateriallage und entsprechendes Herstellungsverfahren |
WO2023105600A1 (ja) * | 2021-12-07 | 2023-06-15 | 武蔵精密工業株式会社 | 蓄電セル、および、蓄電モジュール |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN109509909B (zh) * | 2018-10-17 | 2020-07-03 | 宁德时代新能源科技股份有限公司 | 二次电池 |
KR102279002B1 (ko) * | 2018-11-29 | 2021-07-20 | 주식회사 엘지에너지솔루션 | 전극조립체 |
CN112736227A (zh) * | 2020-12-29 | 2021-04-30 | 天津国安盟固利新材料科技股份有限公司 | 复合阴极以及采用其的二次电池 |
CN114583385B (zh) * | 2022-03-02 | 2024-03-15 | 上海兰钧新能源科技有限公司 | 一种锂电池复合安全隔膜、锂电池电芯及对应的制备方法 |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2011044312A (ja) * | 2009-08-20 | 2011-03-03 | Toshiba Corp | 非水電解質電池および電池パック |
WO2012023501A1 (ja) * | 2010-08-20 | 2012-02-23 | 株式会社 村田製作所 | 非水電解質二次電池 |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3754218B2 (ja) | 1999-01-25 | 2006-03-08 | 三洋電機株式会社 | 非水電解質電池用正極及びその製造方法、ならびこの正極を用いた非水電解質電池及びその製造方法 |
JP3353109B2 (ja) | 1999-04-07 | 2002-12-03 | エバレディ バッテリー カンパニー インコーポレーテッド | 外部水素除去剤を有する電池 |
CN1233053C (zh) * | 2000-12-22 | 2005-12-21 | 吴崇安 | 一种用于棱柱形电池的电极组件 |
US6908711B2 (en) * | 2002-04-10 | 2005-06-21 | Pacific Lithium New Zealand Limited | Rechargeable high power electrochemical device |
JP2004055425A (ja) * | 2002-07-23 | 2004-02-19 | Nissan Motor Co Ltd | 積層型二次電池および電池要素体 |
JP4693373B2 (ja) * | 2004-07-21 | 2011-06-01 | 三洋電機株式会社 | 非水電解質電池 |
JP2006032280A (ja) | 2004-07-21 | 2006-02-02 | Sanyo Electric Co Ltd | 非水電解質電池 |
US7662509B2 (en) * | 2004-10-29 | 2010-02-16 | Medtronic, Inc. | Lithium-ion battery |
JP4988169B2 (ja) | 2005-05-16 | 2012-08-01 | 日立マクセルエナジー株式会社 | リチウム二次電池 |
KR100874387B1 (ko) * | 2006-06-13 | 2008-12-18 | 주식회사 엘지화학 | 둘 이상의 작동 전압을 제공하는 중첩식 이차전지 |
-
2015
- 2015-06-23 EP EP15812730.8A patent/EP3163667B1/en active Active
- 2015-06-23 CN CN201580034353.6A patent/CN106463780B/zh active Active
- 2015-06-23 WO PCT/JP2015/068102 patent/WO2015199101A1/ja active Application Filing
- 2015-06-23 JP JP2016529613A patent/JP6581981B2/ja active Active
- 2015-06-23 US US15/320,678 patent/US10516162B2/en active Active
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2011044312A (ja) * | 2009-08-20 | 2011-03-03 | Toshiba Corp | 非水電解質電池および電池パック |
WO2012023501A1 (ja) * | 2010-08-20 | 2012-02-23 | 株式会社 村田製作所 | 非水電解質二次電池 |
Non-Patent Citations (1)
Title |
---|
See also references of EP3163667A4 * |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2017078108A1 (ja) * | 2015-11-06 | 2017-05-11 | 日立化成株式会社 | リチウムイオン二次電池 |
DE102017202995A1 (de) | 2017-02-24 | 2018-08-30 | Robert Bosch Gmbh | Elektrische Energiespeichereinheit mit mindestens einer elektrisch isolierten Elektrodenmateriallage und entsprechendes Herstellungsverfahren |
WO2023105600A1 (ja) * | 2021-12-07 | 2023-06-15 | 武蔵精密工業株式会社 | 蓄電セル、および、蓄電モジュール |
Also Published As
Publication number | Publication date |
---|---|
CN106463780A (zh) | 2017-02-22 |
US20170155138A1 (en) | 2017-06-01 |
US10516162B2 (en) | 2019-12-24 |
JPWO2015199101A1 (ja) | 2017-05-25 |
EP3163667A1 (en) | 2017-05-03 |
EP3163667B1 (en) | 2022-01-19 |
CN106463780B (zh) | 2019-05-31 |
JP6581981B2 (ja) | 2019-09-25 |
EP3163667A4 (en) | 2017-11-29 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US10573879B2 (en) | Electrolytes and methods for using the same | |
JP6581981B2 (ja) | 非水電解質二次電池およびこれを複数個接続してなる組電池 | |
CN107112584B (zh) | 非水电解液二次电池和非水电解液二次电池的正极 | |
JP5797993B2 (ja) | 非水電解質二次電池 | |
CN107431240B (zh) | 包装件 | |
CN103035921A (zh) | 非水电解质二次电池 | |
US20210050157A1 (en) | Hybrid electrode materials for bipolar capacitor-assisted solid-state batteries | |
US10541453B2 (en) | Battery module for starting a power equipment | |
JP2014006971A (ja) | 非水電解質二次電池及びそれを用いた組電池 | |
JP2012129095A (ja) | 非水電解質二次電池用バイポーラ電極、および、それを用いた非水電解質二次電池。 | |
JP6656370B2 (ja) | リチウムイオン二次電池および組電池 | |
JP5564872B2 (ja) | 非水電解質二次電池 | |
TWI600195B (zh) | 非水電解質二次電池及使用其之組電池 | |
WO2013108841A1 (ja) | 捕捉体を含む非水電解質二次電池 | |
JP2019021563A (ja) | リチウムイオン二次電池およびその製造方法 | |
US20240038996A1 (en) | Cellulose-based fiber-type dispersant for hybrid capacitive electrodes and methods of making the same | |
US20230246182A1 (en) | Additives for high-nickel electrodes and methods of forming the same | |
JP2023111498A (ja) | リチウムイオン二次電池用正極の製造方法 | |
JP2016207611A (ja) | 非水電解質二次電池及びこれを複数個接続してなる組電池及びその製造方法。 | |
JPWO2018198612A1 (ja) | 非水電解質二次電池およびその製造方法 | |
JP2021039820A (ja) | 活物質と導電性炭素材料からなる複合体を含むリチウムイオン二次電池用電極の製造方法 | |
KR20180138395A (ko) | 리튬 이차전지 | |
JP2017228462A (ja) | 非水電解質二次電池の製造方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 15812730 Country of ref document: EP Kind code of ref document: A1 |
|
REEP | Request for entry into the european phase |
Ref document number: 2015812730 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 15320678 Country of ref document: US Ref document number: 2015812730 Country of ref document: EP |
|
ENP | Entry into the national phase |
Ref document number: 2016529613 Country of ref document: JP Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |