WO2014013850A1 - リチウム二次電池およびその製造方法 - Google Patents
リチウム二次電池およびその製造方法 Download PDFInfo
- Publication number
- WO2014013850A1 WO2014013850A1 PCT/JP2013/067465 JP2013067465W WO2014013850A1 WO 2014013850 A1 WO2014013850 A1 WO 2014013850A1 JP 2013067465 W JP2013067465 W JP 2013067465W WO 2014013850 A1 WO2014013850 A1 WO 2014013850A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- secondary battery
- silicon
- lithium secondary
- positive electrode
- containing cyclic
- 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
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
- H01M10/0566—Liquid materials
- H01M10/0567—Liquid materials characterised by the additives
-
- 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
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
- H01M10/0566—Liquid materials
- H01M10/0569—Liquid materials characterised by the solvents
-
- 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
-
- 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
-
- 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
- H01M4/362—Composites
- H01M4/366—Composites as layered products
-
- 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
- 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
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2220/00—Batteries for particular applications
- H01M2220/20—Batteries in motive systems, e.g. vehicle, ship, plane
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0017—Non-aqueous electrolytes
- H01M2300/0025—Organic electrolyte
- H01M2300/0028—Organic electrolyte characterised by the solvent
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0017—Non-aqueous electrolytes
- H01M2300/0025—Organic electrolyte
- H01M2300/0028—Organic electrolyte characterised by the solvent
- H01M2300/0034—Fluorinated solvents
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
-
- 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 lithium secondary battery and a method for manufacturing the same. Specifically, the present invention relates to a lithium secondary battery applicable to a vehicle-mounted power source and a method for manufacturing the same.
- This application claims the priority based on the Japan patent application 2012-158487 for which it applied on July 17, 2012, The whole content of the application is integrated in this specification as a reference.
- Lithium secondary batteries are lightweight and can obtain a high energy density, and are therefore preferably used as so-called portable power sources such as personal computers and portable terminals and vehicle power sources. In particular, it is highly important as a high-output power source for driving vehicles such as electric vehicles and hybrid vehicles. In such a lithium secondary battery, it has been proposed to add cyclic siloxane to the non-aqueous electrolyte for the purpose of improving cycle characteristics and the like. Patent documents 1 to 4 are cited as documents disclosing this type of prior art.
- the transition metal tends to elute from the positive electrode active material by charging and discharging at a high potential. Since the eluted transition metal deactivates lithium that contributes to charge and discharge, it is considered that this can cause deterioration of cycle characteristics. As a result of intensive studies, the present inventor has found a compound capable of suppressing the deactivation of lithium caused by the eluted transition metal, and has completed the present invention.
- the present invention relates to an improvement of a 4.2 V class or higher lithium secondary battery, and an object thereof is to provide a lithium secondary battery capable of improving cycle characteristics at a 4.2 V class or higher. Another object is to provide a method for producing a lithium secondary battery having such performance.
- the present invention provides a lithium secondary battery of 4.2 V class or higher using a lithium transition metal composite oxide as a positive electrode active material.
- a silicon-containing cyclic compound and / or a reaction product thereof is present in the vicinity of the negative electrode constituting the lithium secondary battery.
- this silicon-containing cyclic compound at least one of atoms constituting the ring is a silicon atom and has at least one vinyl group.
- the silicon-containing cyclic compound having at least one vinyl group and / or the reaction product thereof is transferred to the transition metal eluted from the positive electrode active material at least in the vicinity of the negative electrode. It acts to suppress the deterioration of the resulting cycle characteristics. Therefore, according to the present invention, improvement in cycle characteristics in a secondary battery of 4.2V class or higher is realized.
- 4.2 V class or higher lithium secondary battery refers to a redox potential (operating potential) of the positive electrode active material within a SOC (State of Charge) range of 0% to 100%.
- SOC State of Charge
- a lithium secondary battery having a region of 4.2 V or higher vs. Li / Li + ).
- Such a secondary battery can also be grasped as a lithium secondary battery in which the potential of the positive electrode is 4.2 V or more in at least a partial range of SOC 0% to 100%.
- the silicon-containing cyclic compound has the formula (1): (In the formula (1), R 1 and R 2 are the same or different and both are organic groups having 1 to 12 carbon atoms, and at least one of R 1 and R 2 contains a vinyl group. N is 3 A vinyl group-containing cyclic siloxane represented by:
- all substituents bonded to silicon atoms constituting the ring are vinyl groups.
- the positive electrode active material is a lithium transition metal composite oxide having a spinel structure including Li and Ni and Mn as transition metal elements.
- the spinel structure lithium transition metal composite oxide is a preferred example of a positive electrode active material having a region where the operating potential is 4.2 V or higher.
- the cycle characteristics can be significantly improved by the silicon-containing cyclic compound.
- the lithium secondary battery includes a non-aqueous electrolyte
- the non-aqueous electrolyte includes fluorinated carbonate as a non-aqueous solvent.
- non-aqueous electrolytes tend to be oxidatively decomposed at high potentials.
- a non-aqueous electrolyte containing a fluorinated carbonate having excellent oxidation resistance the oxidative decomposition of the non-aqueous electrolyte is suppressed.
- Such a non-aqueous electrolyte is suitable as a non-aqueous electrolyte for a secondary battery of 4.2 V class or higher that charges and discharges at a high potential.
- a method for producing a lithium secondary battery of 4.2 V class or higher includes preparing a positive electrode and a negative electrode containing a lithium transition metal composite oxide as a positive electrode active material, and supplying a silicon-containing cyclic compound to at least the negative electrode.
- the silicon-containing cyclic compound at least one of atoms constituting the ring is a silicon atom and has at least one vinyl group.
- the silicon-containing cyclic compound having at least one vinyl group and / or the reaction product thereof acts to suppress a decrease in cycle characteristics due to the transition metal eluted from the positive electrode active material.
- the cycle characteristics in a secondary battery of 4.2V class or higher are improved.
- the supply of the silicon-containing cyclic compound is to prepare a non-aqueous electrolyte containing the silicon-containing cyclic compound, and the prepared non-aqueous electrolyte is used as the positive electrode.
- the silicon-containing cyclic compound is supplied from the non-aqueous electrolyte that can come into contact with the electrode body, and the effect of improving cycle characteristics by the silicon-containing cyclic compound is suitably exhibited.
- the silicon-containing cyclic compound is represented by the formula (1): (In the formula (1), R 1 and R 2 are the same or different and both are organic groups having 1 to 12 carbon atoms, and at least one of R 1 and R 2 contains a vinyl group. N is 3 A vinyl group-containing cyclic siloxane represented by the following formula:
- all substituents bonded to silicon atoms constituting the ring are vinyl groups.
- a lithium transition metal composite oxide having a spinel structure containing Li as the positive electrode active material and Ni and Mn as transition metal elements is used.
- the positive electrode active material having a high operating potential as described above the cycle characteristics can be significantly improved by the silicon-containing cyclic compound.
- the lithium secondary battery includes a non-aqueous electrolyte, and fluorinated carbonate is used as a non-aqueous solvent for the non-aqueous electrolyte.
- a non-aqueous electrolyte is suitable as a non-aqueous electrolyte for a secondary battery of 4.2 V class or higher that charges and discharges at a high potential.
- a non-aqueous electrolyte for a secondary battery is provided.
- This non-aqueous electrolyte is applied to a 4.2 V class or higher lithium secondary battery using a lithium transition metal composite oxide as a positive electrode active material.
- the non-aqueous electrolyte includes a silicon-containing cyclic compound. Further, in the silicon-containing cyclic compound, at least one of atoms constituting the ring is a silicon atom and has at least one vinyl group.
- a 4.2 V class or higher lithium secondary battery using a lithium transition metal composite oxide as a positive electrode active material is provided. This secondary battery is constructed using any of the non-aqueous electrolytes disclosed herein.
- a non-aqueous electrolyte for a secondary battery (preferably a lithium secondary battery) is provided.
- This non-aqueous electrolyte contains a silicon-containing cyclic compound.
- the silicon-containing cyclic compound at least one of atoms constituting the ring is a silicon atom and has at least one vinyl group.
- the ratio (V N / S TOTAL ) of the number of vinyl groups (V N ) to the total number of substituents bonded to the silicon atoms constituting the ring (S TOTAL ) exceeds 50%. It is preferable.
- an additive for a non-aqueous electrolyte solution containing the silicon-containing cyclic compound (typically an additive comprising a silicon-containing cyclic compound in which the ratio (V N / S TOTAL ) exceeds 50% is provided.
- a non-aqueous electrolyte solution containing the silicon-containing cyclic compound typically an additive comprising a silicon-containing cyclic compound in which the ratio (V N / S TOTAL ) exceeds 50% is provided.
- the lithium secondary battery disclosed herein is excellent in cycle characteristics in high potential charge / discharge. Therefore, taking advantage of this feature, it can be suitably used as a drive power source for vehicles such as hybrid vehicles (HV), plug-in hybrid vehicles (PHV), electric vehicles (EV) and the like. According to the present invention, there is provided a vehicle equipped with any of the lithium secondary batteries disclosed herein (which may be in the form of an assembled battery in which a plurality of batteries are connected).
- FIG. 2 is a cross-sectional view taken along line II-II in FIG. It is a perspective view which shows typically the state which winds and produces the electrode body which concerns on one Embodiment. It is a fragmentary sectional view which shows the coin-type battery produced in the Example. It is a graph which shows the relationship between the cycle number in a capacity maintenance rate measurement test, and a capacity maintenance rate. It is a graph which shows the relationship between the cycle number in a capacity maintenance rate measurement test, and a capacity maintenance rate. It is a side view showing typically a vehicle (automobile) provided with a lithium secondary battery concerning one embodiment. It is a figure which shows the Cole-Cole plot of the alternating current impedance before a cycle (In the figure, Z 'shows a real part and Z "shows an imaginary part.).
- secondary battery generally refers to a battery that can be repeatedly charged and discharged.
- a storage battery ie, a chemical battery
- a capacitor ie, a physical battery
- an electric double layer capacitor ie, a battery that uses lithium ions (Li ions) as electrolyte ions and is charged and discharged by the movement of charges associated with Li ions between the positive and negative electrodes.
- a secondary battery using a metal ion other than Li ion (for example, sodium ion) as a charge carrier can be included in the “lithium secondary battery” in this specification.
- a battery generally called a lithium ion secondary battery is a typical example included in the lithium secondary battery in this specification.
- the lithium secondary battery 100 includes a rectangular box-shaped battery case 10 and a wound electrode body 20 accommodated in the battery case 10.
- the battery case 10 has an opening 12 on the upper surface.
- the opening 12 is sealed by the lid 14 after the wound electrode body 20 is accommodated in the battery case 10 from the opening 12.
- the battery case 10 also contains a nonaqueous electrolyte (nonaqueous electrolyte solution) 25.
- the lid body 14 is provided with an external positive terminal 38 and an external negative terminal 48 for external connection, and a part of the terminals 38 and 48 protrudes to the surface side of the lid body 14.
- a part of the external positive terminal 38 is connected to the internal positive terminal 37 inside the battery case 10, and a part of the external negative terminal 48 is connected to the internal negative terminal 47 inside the battery case 10.
- the wound electrode body 20 includes a long sheet-like positive electrode (positive electrode sheet) 30 and a long sheet-like negative electrode (negative electrode sheet) 40.
- the positive electrode sheet 30 includes a long positive electrode current collector 32 and a positive electrode mixture layer 34 formed on at least one surface (typically both surfaces) thereof.
- the negative electrode sheet 40 includes a long negative electrode current collector 42 and a negative electrode mixture layer 44 formed on at least one surface (typically both surfaces) thereof.
- the wound electrode body 20 also includes two long sheet-like separators (separator sheets) 50A and 50B.
- the positive electrode sheet 30 and the negative electrode sheet 40 are laminated via two separator sheets 50A and 50B, and the positive electrode sheet 30, the separator sheet 50A, the negative electrode sheet 40, and the separator sheet 50B are laminated in this order.
- the laminated body is formed into a wound body by being wound in the longitudinal direction, and is further formed into a flat shape by crushing the rolled body from the side surface direction and causing it to be ablated.
- the electrode body is not limited to a wound electrode body. Depending on the shape of the battery and the purpose of use, an appropriate shape and configuration, such as a laminate mold, can be employed as appropriate.
- the positive electrode mixture layer 34 formed on the surface of the positive electrode current collector 32 and the surface of the negative electrode current collector 42 are formed at the center of the wound electrode body 20 in the width direction (direction orthogonal to the winding direction). A portion in which the negative electrode composite material layer 44 thus overlapped and densely stacked is formed. Further, at one end in the width direction of the positive electrode sheet 30, a portion where the positive electrode current collector layer 34 is not formed and the positive electrode current collector 32 is exposed (positive electrode mixture layer non-forming portion 36) is provided. .
- the positive electrode mixture layer non-forming portion 36 is in a state of protruding from the separator sheets 50 ⁇ / b> A and 50 ⁇ / b> B and the negative electrode sheet 40.
- the positive electrode current collector laminated portion 35 in which the positive electrode mixture layer non-forming portion 36 of the positive electrode current collector 32 overlaps is formed at one end in the width direction of the wound electrode body 20. Further, similarly to the case of the positive electrode sheet 30 at one end, the negative electrode current collector stack in which the negative electrode mixture layer non-forming portion 46 of the negative electrode current collector 42 is overlapped with the other end in the width direction of the wound electrode body 20. A portion 45 is formed.
- the separator sheets 50 ⁇ / b> A and 50 ⁇ / b> B have a width that is larger than the width of the laminated portion of the positive electrode mixture layer 34 and the negative electrode mixture layer 44 and smaller than the width of the wound electrode body 20.
- a positive electrode current collector constituting a positive electrode (typically, a positive electrode sheet) of a lithium secondary battery a conductive member made of a metal having good conductivity is preferably used.
- a conductive member for example, aluminum or an alloy containing aluminum as a main component can be used.
- the shape of the positive electrode current collector can be different depending on the shape of the battery and is not particularly limited, and may be various forms such as a rod shape, a plate shape, a sheet shape, a foil shape, and a mesh shape.
- the thickness of the positive electrode current collector is not particularly limited, and can be, for example, 5 ⁇ m to 30 ⁇ m.
- the positive electrode mixture layer can contain additives such as a conductive material and a binder (binder) as necessary.
- the positive electrode active material one or more of various materials known to be usable as a positive electrode active material for lithium secondary batteries can be used without particular limitation.
- a lithium transition metal compound such as a layered structure or spinel structure containing lithium (Li) and at least one transition metal element as a constituent metal element, a polyanion type (for example, olivine type) lithium transition metal compound, or the like may be used. it can. More specifically, for example, the following compounds can be used.
- a lithium transition metal composite oxide typically represented by the following general formula (A1): LiMn 2-x M x O 4 ;
- x is 0 ⁇ x ⁇ 2, and typically 0 ⁇ x ⁇ 1.
- M can be any metallic or nonmetallic element other than Mn.
- a composition in which M contains at least one transition metal element is preferred. Specific examples include LiMn 2 O 4 , LiNi 0.5 Mn 1.5 O 4 , LiCrMnO 4 and the like.
- a compound in which M in the general formula (A1) contains at least Ni for example, a spinel represented by the following general formula (A2): LiNi p M 1 q Mn 2-pq O 4 ;
- Examples include lithium transition metal composite oxides having a structure.
- 0 ⁇ p, 0 ⁇ q, and p + q ⁇ 2 typically p + q ⁇ 1).
- q 0 and 0.2 ⁇ p ⁇ 0.6.
- the charge of the LiNiMn composite oxide having a spinel structure (for example, LiNi 0.5 Mn 1.5 O 4 ) at the end of charging
- the positive electrode potential can be increased (typically higher than 4.5 V (vs. Li / Li + ) or more), and a 5 V-class lithium secondary battery can be constructed.
- M 1 is selected from any metal element or non-metal element other than Ni and Mn (for example, Fe, Co, Cu, Cr, Zn, and Al). 1 type or 2 types or more). It is preferable that M 1 contains at least one of trivalent Fe and Co. Moreover, it is preferable that 0 ⁇ q ⁇ 0.3 and 1 ⁇ 2p + q.
- LiMO represented by 2 typically a lithium transition metal composite oxide of a layered structure.
- M includes at least one transition metal element such as Ni, Co, and Mn, and may further include another metal element or a nonmetal element. Specific examples include LiNiO 2 and LiNi 1/3 Co 1/3 Mn 1/3 O 2 .
- M includes at least one transition metal element such as Mn, Fe, and Co, and may further include another metal element or a nonmetal element. Specific examples include Li 2 MnO 3 and Li 2 PtO 3 .
- LiMPO 4 (phosphate) lithium transition metal compound represented by the general formula LiMPO 4 (phosphate).
- M includes at least one transition metal element such as Mn, Fe, Ni, and Co, and may further include another metal element or a nonmetal element.
- Specific examples include LiMnPO 4 and LiFePO 4 .
- M includes at least one transition metal element such as Mn, Ni, and Co, and may further include another metal element or a nonmetal element.
- Specific examples include Li 2 MnPO 4 F.
- (6) a solid solution of LiMO 2 and Li 2 MO 3.
- LiMO 2 refers to the composition represented by the general formula described in (2) above
- Li 2 MO 3 refers to the composition represented by the general formula described in (3) above.
- a solid solution represented by 0.5LiNi 1/3 Mn 1/3 Co 1/3 O 2 —0.5Li 2 MnO 3 can be given.
- the positive electrode active material is a lithium secondary battery in which the working potential (vs. Li / Li + ) in at least a part of SOC 0% to 100% is a general lithium battery (the upper limit of the working potential is about 4.1V). ) Higher than.
- a positive electrode active material having an operating potential of 4.2 V (vs. Li / Li + ) or more can be preferably used.
- a positive electrode active material having a maximum operating potential of 4.2 V (vs. Li / Li + ) or more at SOC 0% to 100% can be preferably used.
- LiNi P Mn 2-P O 4 (0.2 ⁇ P ⁇ 0.6; for example, LiNi 0.5 Mn 1.5 O 4 ), LiMn 2 O 4 , LiNiPO 4 , LiCoPO 4 , LiMnPO 4 , LiNi 1/3 Co 1/3 Mn 1/3 O 2 , 0.5LiNi 1/3 Mn 1/3 Co 1/3 O 2 -0.5Li 2 MnO 3 and the like.
- the working potential (vs.
- Li / Li + of the positive electrode active material is preferably 4.3 V or higher (for example, 4.35 V or higher, more preferably 4.5 V or higher), 4.6 V or higher (for example, 4.8 V or higher, further 4 .9V or more) is particularly preferable.
- the upper limit of the operating potential (vs. Li / Li + ) is not particularly limited, but may be 5.5 V or lower (for example, 5.3 V or lower, typically 5.1 V or lower).
- a triode cell is constructed using an electrolyte containing about 1 mol / L LiPF 6 inside. The SOC value of this cell is adjusted in increments of 5% from 0% SOC to 100% SOC based on the theoretical capacity of the cell. For example, adjustment is performed by constant current charging. The positive electrode potential after the cell adjusted to each SOC value is left for 1 hour is measured, and the positive electrode potential (vs.
- Li / Li + is set as the operating potential of the positive electrode active material at the SOC value.
- the operating potential of the positive electrode active material is the highest between SOC 0% and 100% in a range including SOC 100%. Therefore, the operating potential of the positive electrode active material is normally 100% SOC (that is, fully charged).
- the upper limit (for example, whether it is 4.2 V or more) of the operating potential of the positive electrode active material can be grasped.
- the shape of the positive electrode active material is usually preferably a particle shape having an average particle diameter of about 1 ⁇ m to 20 ⁇ m (eg, 2 ⁇ m to 10 ⁇ m).
- the “average particle size” means a particle size at an integrated value of 50% in a particle size distribution measured based on a particle size distribution measuring apparatus based on a laser scattering / diffraction method, that is, 50%. It shall mean the volume average particle diameter.
- a conductive powder material such as carbon powder or carbon fiber is preferably used.
- carbon powder various carbon blacks such as acetylene black, furnace black, ketjen black, and graphite powder are preferable.
- conductive fibers such as carbon fibers and metal fibers, metal powders such as copper and nickel, and organic conductive materials such as polyphenylene derivatives can be used singly or as a mixture of two or more. .
- Bind materials include various polymer materials.
- an aqueous composition a composition using water or a mixed solvent containing water as a main component as a dispersion medium of active material particles
- water-soluble or water-dispersible these polymer materials can be preferably used as the binder.
- water-soluble or water-dispersible polymer materials include cellulose polymers such as carboxymethyl cellulose (CMC); polyvinyl alcohol (PVA); fluorine resins such as polytetrafluoroethylene (PTFE); vinyl acetate polymers; styrene butadiene rubber Rubbers such as (SBR) and acrylic acid-modified SBR resin (SBR latex);
- cellulose polymers such as carboxymethyl cellulose (CMC); polyvinyl alcohol (PVA); fluorine resins such as polytetrafluoroethylene (PTFE); vinyl acetate polymers; styrene butadiene rubber Rubbers such as (SBR) and acrylic acid-modified SBR resin (SBR latex);
- a solvent-based composition a composition in which the dispersion medium of active material particles is mainly an organic solvent
- PVDF polyvinylidene fluoride
- PVDC polyvinylidene chloride
- Polymer materials such as vinyl halide resins such as polyethylene oxide
- the proportion of the positive electrode active material in the positive electrode mixture layer is preferably more than about 50% by mass, and preferably about 70% to 97% by mass (for example, 75% to 95% by mass).
- the ratio of the additive to the positive electrode mixture layer is not particularly limited, but the ratio of the conductive material is about 1 to 20 parts by mass (for example, 2 to 10 parts by mass with respect to 100 parts by mass of the positive electrode active material). (Typically 3 to 7 parts by mass).
- the ratio of the binder is about 0.8 to 10 parts by mass (for example, 1 to 7 parts by mass, typically 2 to 5 parts by mass) with respect to 100 parts by mass of the positive electrode active material. It is preferable.
- the method for producing the positive electrode as described above is not particularly limited, and a conventional method can be appropriately employed.
- a positive electrode active material, if necessary, a conductive material, a binder, etc. are mixed with an appropriate solvent (aqueous solvent, non-aqueous solvent or a mixed solvent thereof) to form a paste-like or slurry-like positive electrode mixture layer
- a composition is prepared.
- the mixing operation can be performed using, for example, a suitable kneader (planetary mixer, homodisper, clear mix, fill mix, etc.).
- a solvent used for preparing the composition both an aqueous solvent and a non-aqueous solvent can be used.
- the aqueous solvent is not particularly limited as long as it is water-based as a whole, and water or a mixed solvent mainly composed of water can be preferably used.
- Preferable examples of the non-aqueous solvent include N-methyl-2-pyrrolidone (NMP), methyl ethyl ketone, toluene and the like.
- the composition thus prepared is applied to the positive electrode current collector, and the solvent is evaporated by drying, followed by compression (pressing).
- a technique for applying the composition to the positive electrode current collector a technique similar to a conventionally known method can be appropriately employed.
- the composition can be suitably applied to the positive electrode current collector by using an appropriate application device such as a slit coater, a die coater, a gravure coater, or a comma coater.
- an appropriate application device such as a slit coater, a die coater, a gravure coater, or a comma coater.
- drying a solvent it can dry favorably by using natural drying, a hot air, low-humidity air, a vacuum, infrared rays, far infrared rays, and an electron beam individually or in combination.
- a conventionally known compression method such as a roll press method or a flat plate press method can be employed.
- the thickness may be measured with a film thickness measuring instrument, and the press pressure may be adjusted to compress the film a plurality of times until a desired thickness is obtained. In this way, a positive electrode in which the positive electrode mixture layer is formed on the positive electrode current collector is obtained.
- the basis weight per unit area of the positive electrode mixture layer on the positive electrode current collector (the coating amount in terms of solid content of the composition for forming the positive electrode mixture layer) is not particularly limited, but a sufficient conductive path From the viewpoint of securing a (conduction path), it is 3 mg / cm 2 or more (for example, 5 mg / cm 2 or more, typically 6 mg / cm 2 or more) per side of the positive electrode current collector, and 45 mg / cm 2 or less (for example, 28 mg / cm 2 or less, typically 15 mg / cm 2 or less).
- the negative electrode current collector constituting the negative electrode typically, the negative electrode sheet
- a conductive member made of a metal having good conductivity is preferably used as in the conventional lithium secondary battery.
- a conductive member for example, copper or an alloy containing copper as a main component can be used.
- the shape of the negative electrode current collector can be different depending on the shape of the battery and is not particularly limited, and may be various forms such as a rod shape, a plate shape, a sheet shape, a foil shape, and a mesh shape.
- the thickness of the negative electrode current collector is not particularly limited, and can be about 5 ⁇ m to 30 ⁇ m.
- the negative electrode mixture layer contains a negative electrode active material capable of occluding and releasing Li ions serving as charge carriers.
- a negative electrode active material capable of occluding and releasing Li ions serving as charge carriers.
- the 1 type (s) or 2 or more types of the material conventionally used for a lithium secondary battery can be used.
- Examples of such a negative electrode active material include carbon materials that are generally used in lithium secondary batteries.
- Representative examples of the carbon material include graphite carbon (graphite) and amorphous carbon.
- a particulate carbon material (carbon particles) containing a graphite structure (layered structure) at least partially is preferably used. Of these, the use of a carbon material mainly composed of natural graphite is preferred.
- the natural graphite may be a spheroidized graphite.
- a carbonaceous powder having a graphite surface coated with amorphous carbon may be used.
- oxides such as lithium titanate, simple substances such as silicon materials and tin materials, alloys, compounds, and composite materials using the above materials in combination.
- the proportion of the negative electrode active material in the negative electrode mixture layer exceeds about 50% by mass, and is about 90% to 99% by mass (eg, 95% to 99% by mass, typically 97% to 99% by mass). Preferably there is.
- the negative electrode mixture layer requires one or more binders, thickeners, and other additives that can be blended in the negative electrode mixture layer of a typical lithium secondary battery. It can be contained accordingly.
- the binder include various polymer materials.
- what can be contained in the positive electrode mixture layer can be preferably used for an aqueous composition or a solvent-based composition.
- Such a binder may be used as a thickener and other additives in the composition for forming a negative electrode mixture layer, in addition to being used as a binder.
- the proportion of these additives in the negative electrode mixture layer is not particularly limited, but is approximately 0.8% to 10% by mass (for example, approximately 1% to 5% by mass, typically 1% to 3% by mass). It is preferable that
- the method for producing the negative electrode is not particularly limited, and a conventional method can be adopted.
- a negative electrode active material is mixed with a binder or the like in the appropriate solvent (aqueous solvent, organic solvent, or mixed solvent thereof) to prepare a paste or slurry-like composition for forming a negative electrode mixture layer.
- the composition prepared in this manner is applied to the negative electrode current collector, the solvent is volatilized by drying, and then compressed (pressed).
- a negative electrode mixture layer can be formed on a negative electrode current collector using the composition, and a negative electrode provided with the negative electrode mixture layer can be obtained.
- the mixing, coating, drying, and compression methods can employ the same means as in the above-described production of the positive electrode.
- the basis weight per unit area of the negative electrode composite material layer on the negative electrode current collector (the coating amount in terms of solid content of the composition for forming the negative electrode composite material layer) is not particularly limited, but sufficient conductive paths From the viewpoint of securing a (conduction path), it is 2 mg / cm 2 or more (for example, 3 mg / cm 2 or more, typically 4 mg / cm 2 or more) per side of the negative electrode current collector, and 40 mg / cm 2 or less (for example, 22 mg / cm 2 or less, typically 10 mg / cm 2 or less).
- the silicon-containing cyclic compound and / or the reaction product thereof is in the vicinity of the negative electrode (typically the negative electrode surface, the negative electrode (typically the negative electrode mixture layer)). May be present).
- the silicon-containing cyclic compound disclosed in the technology disclosed herein at least one of the atoms constituting the ring is a silicon atom (Si) and has at least one vinyl group.
- the silicon-containing cyclic compound has a cyclic structure containing Si and a vinyl group, at least in the vicinity of the negative electrode, the compound and / or the reaction product thereof is deteriorated in cycle characteristics due to the transition metal eluted from the positive electrode active material. It can act to suppress.
- a transition metal typically Mn
- Mn a transition metal eluted from the positive electrode by high-potential charge / discharge
- This is considered to be caused by the deterioration of the cycle characteristics due to the deactivation of lithium that can contribute to charge and discharge. Therefore, when the silicon-containing cyclized product is included in the battery so that it can be present in the vicinity of the negative electrode (typically the surface of the negative electrode), the silicon-containing cyclized product is deposited on the surface of the electrode (mainly the negative electrode) ( Typically forms a coating). It is considered that this precipitate (coating) acts to suppress the lithium deactivation and contributes to the suppression of the deterioration of cycle characteristics.
- This cycle characteristic improving effect cannot be realized by a silicon-containing compound having a vinyl group but not cyclic (for example, a linear or branched compound, typically a vinyl group-containing chain siloxane). It has been confirmed by the present inventors that even a silicon-containing cyclic compound (typically a vinyl group-free cyclic siloxane) that is not present cannot be realized. Although the mechanism is unknown, it is a silicon-containing compound, and it is assumed that having a cyclic structure and a vinyl group plays an important role in improving cycle characteristics.
- the “silicon-containing cyclic compound and / or reaction product thereof” disclosed herein means a component (typically a precipitate) derived from the silicon-containing cyclic compound as described above. Can be interpreted as including at least one of a silicon-containing cyclic compound and a reaction product thereof. The presence or absence of precipitates (film formation) derived from the silicon-containing compound can be confirmed, for example, by taking a sample from the electrode surface and using a known analysis means such as ICP (High Frequency Inductively Coupled Plasma) emission analysis. .
- ICP High Frequency Inductively Coupled Plasma
- the silicon-containing cyclic compound at least one of atoms constituting the ring is a silicon atom (Si).
- the number of atoms constituting the ring is not particularly limited, but is preferably 3 to 20 in consideration of film-forming properties and the like, and is preferably 3 to 12 (eg, 3 to 10, typically 8). preferable.
- the atoms constituting the ring preferably include Si and an oxygen atom (O), and the atoms constituting the ring are more preferably composed of Si and O. Typically, it may be a so-called cyclic siloxane in which Si and O are alternately continuous.
- the silicon-containing cyclic compound has at least one vinyl group.
- the number of vinyl groups is not particularly limited as long as it is 1 or more, but it is suitably 1 to 20, and preferably 2 to 12 (eg, 3 to 10, typically 4 to 6). Moreover, it is preferable that at least one of the vinyl groups (for example, two or more of the vinyl groups, typically all of the vinyl groups) is bonded to a silicon atom constituting the ring.
- the silicon-containing cyclic compound has a ratio (V N / S) of the number of vinyl groups (V N ) in the total number of substituents (S TOTAL ) bonded to silicon atoms constituting the ring.
- TOTAL is preferably more than 50%.
- the ratio (V N / S TOTAL ) is more preferably 70% or more (for example, 80% or more, typically 90% or more).
- all substituents bonded to silicon atoms constituting the ring are vinyl groups.
- a silicon-containing cyclic compound in which the ratio (V N / S TOTAL ) is 100% is particularly preferable.
- Preferable examples of the silicon-containing cyclic compound disclosed herein include formula (1):
- the vinyl group containing cyclic siloxane represented by these is mentioned.
- R 1 and R 2 can both be organic groups having 1 to 12 carbon atoms.
- R 1 and R 2 may be the same or different.
- at least one of R 1 and R 2 contains a vinyl group.
- n is an integer of 3 to 10.
- R 1 and R 2 may be an organic group having 1 to 12 carbon atoms.
- the number of carbon atoms is preferably 1 to 6 (eg 1 to 4, typically 1 or 2).
- Examples of such an organic group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, n-pentyl group, and 1-methylbutyl.
- Chain alkyl groups such as 2-methylbutyl group, 3-methylbutyl group, 1-methyl-2-methylpropyl group, 2,2-dimethylpropyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group Cyclic alkyl groups such as cyclohexyl group and norbornanyl group; alkenyl groups such as vinyl group, 1-propenyl group, allyl group, butenyl group and 1,3-butadienyl group; alkynyl groups such as ethynyl group, propynyl group and butynyl group; A halogenated alkyl group such as a trifluoropropyl group; an alkyl group having a saturated heterocyclic group such as a 3-pyrrolidinopropyl group; An aryl group such as a phenyl group which may have a kill group; an aralkyl group such as a phenyl
- the organic group is preferably a methyl group, an ethyl group, a vinyl group, a propenyl group, or a phenyl group, and particularly preferably a methyl group or a vinyl group.
- At least one of R 1 and R 2 contains a vinyl group.
- at least one of R 1 and R 2 is a vinyl group.
- at least one of R 1 and R 2 can be an organic group containing a vinyl group.
- An alkenyl group is mentioned as such an organic group containing a vinyl group.
- the number of carbon atoms of the alkenyl group is not particularly limited, but is suitably 3 to 8 (for example, 3 to 6, typically 3 or 4) from the viewpoint of suitably expressing the action of the cyclic siloxane.
- alkenyl group examples include an allyl group, a butenyl group, a 1,3-butadienyl group, a pentenyl group, a hexenyl group, a heptenyl group, and an octenyl group.
- R 1 and R 2 only, or both of R 1 and R 2
- at least one of R 1 and R 2 is preferably is a vinyl group. From the viewpoint of reducing the initial resistance, it is preferable that both R 1 and R 2 are vinyl groups.
- N in the above formula (1) is an integer of 3 to 10.
- n is preferably an integer of 3 to 6, more preferably an integer of 4 to 6, and particularly preferably 4.
- cyclic siloxane containing vinyl groups include vinyl group-containing cyclotrisiloxane, vinyl group-containing cyclotetrasiloxane, vinyl group-containing cyclopentasiloxane, vinyl group-containing cyclohexasiloxane, vinyl group-containing cycloheptasiloxane, Examples include vinyl group-containing cyclooctasiloxane, vinyl group-containing cyclononasiloxane, and vinyl group-containing cyclodecasiloxane.
- vinyl group-containing cyclotetrasiloxane vinyl group-containing cyclopentasiloxane, and vinyl group-containing cyclohexasiloxane are preferable, and vinyl group-containing cyclotetrasiloxane is particularly preferable.
- vinyl group-containing cyclotrisiloxane examples include cyclotrisiloxane having one vinyl group such as 2-vinyl-2,4,4,6,6-pentamethylcyclotrisiloxane, 2,4-divinyl-2, Cyclotrisiloxane having two vinyl groups such as 4,6,6-tetramethylcyclotrisiloxane, cyclotrisiloxane having three vinyl groups such as 2,4,6-trivinyl-2,4,6-trimethylcyclotrisiloxane Cyclotrisiloxane having four vinyl groups such as trisiloxane, 2,4,6,6-tetravinyl-2,4-dimethylcyclotrisiloxane, 2,4,4,6,6-pentavinyl-2-methylcyclo Cyclotrisiloxane having 5 vinyl groups such as trisiloxane, hexavinylcyclotrisiloxane (2,2,4,4,6,6- Kisa vinyl cyclotrisiloxan
- 2,4,6-trivinyl-2,4,6-trimethylcyclotrisiloxane and hexavinylcyclotrisiloxane are compounds in which vinyl groups are bonded to all Si constituting the ring of the cyclic siloxane.
- Hexavinylcyclotrisiloxane is a compound in which two vinyl groups are bonded to Si (typically all Si) constituting the ring of a cyclic siloxane.
- 2,4,6-trivinyl-2,4,6-trimethylcyclotrisiloxane is preferred.
- cyclotrisiloxane having 4 or more vinyl groups (for example, 5 or 6) is preferable, and hexavinylcyclotrisiloxane is more preferable.
- vinyl group-containing cyclotetrasiloxane examples include cyclotetrasiloxane having one vinyl group such as 2-vinyl-2,4,4,6,6,8,8-heptamethylcyclotetrasiloxane, 2,4- Cyclotetrasiloxane having two vinyl groups such as divinyl-2,4,6,6,8,8-hexamethylcyclotetrasiloxane, 2,4,6-trivinyl-2,4,6,8,8-penta Cyclotetrasiloxane having three vinyl groups such as methylcyclotetrasiloxane, cyclotetrasiloxane having four vinyl groups such as 2,4,6,8-tetravinyl-2,4,6,8-tetramethylcyclotetrasiloxane Cycloteto having 5 vinyl groups such as siloxane, 2,4,6,8,8-pentavinyl-2,4,6-trimethylcyclotetrasiloxane Cyclotetrasiloxane having 6 vinyl groups such as si
- Examples thereof include cyclotetrasiloxane having 8 vinyl groups.
- 2,4,6,8-tetravinyl-2,4,6,8-tetramethylcyclotetrasiloxane and octavinylcyclotetrasiloxane have a vinyl group bonded to all Si constituting the cyclic siloxane ring.
- the octavinylcyclotetrasiloxane is a compound in which two vinyl groups are bonded to Si (typically all Si) constituting the ring of the cyclic siloxane. Of these, 2,4,6,8-tetravinyl-2,4,6,8-tetramethylcyclotetrasiloxane is preferable.
- cyclotetrasiloxane having 5 or more vinyl groups (for example, 6, 7 or 8) is preferable, and octavinylcyclotetrasiloxane is more preferable.
- vinyl group-containing cyclopentasiloxane examples include 2-vinyl-2,4,4,6,6,8,8,10,10-nonamethylcyclopentasiloxane and 2,4,6,8,10-pentavinyl.
- -2,4,6,8,10-pentamethylcyclopentasiloxane 2,4,6,6,8,8,10,10-octavinyl-2,4-dimethylcyclopentasiloxane
- 2,4,4, 6,6,8,8,10,10-nonavinyl-2-methylcyclopentasiloxane decavinylcyclopentasiloxane (2,2,4,4,6,
- Examples of the vinyl group-containing cyclohexasiloxane include 2,4,6,8,10,12-hexavinyl-2,4,6,8,10,12-hexamethylcyclohexasiloxane, 2,4,6,6. , 8,8,10,10,12,12-decavinyl-2,4-dimethylcyclohexasiloxane, 2,2,4,4,6,6,8,8,10,10,12,12-dodecylvinyl Examples include cyclohexasiloxane.
- Examples of the vinyl group-containing cycloheptasiloxane include 2,4,6,8,10,12,14-heptavinyl-2,4,6,8,10,12,14-heptamethylcycloheptasiloxane, 2,2 4, 4, 6, 6, 8, 8, 10, 10, 12, 12, 14, 14-tetradecylvinylcycloheptasiloxane, and the like.
- Examples of the vinyl group-containing cyclooctasiloxane include 2,4,6,8,10,12,14,16-octavinyl-2,4,6,8,10,12,14,16-octamethylcyclooctasiloxane.
- 2,2,4,4,6,6,8,8,10,10,12,12,14,14,16,16-hexadecylvinylcyclooctasiloxane examples include 2,4,6,8,10,12,14,16,18-nonavinyl-2,4,6,8,10,12,14,16,18-nona. Examples include methylcyclononasiloxane, 2,2,4,6,6,8,8,10,10,12,12,14,14,16,16,18,18-octadecylvinylcyclononasiloxane.
- vinyl group-containing cyclodecasiloxane examples include 2,4,6,8,10,12,14,16,18,20-decavinyl-2,4,6,8,10,12,14,16,18. , 20-decamethylcyclodecasiloxane and the like.
- the separator (separator sheet) disposed so as to separate the positive electrode and the negative electrode may be a member that insulates the positive electrode mixture layer and the negative electrode mixture layer and allows the electrolyte to move.
- the separator include those made of a porous polyolefin resin.
- a porous separator sheet made of a synthetic resin for example, made of polyethylene, polypropylene, or a polyolefin having a structure of two or more layers combining these
- This separator sheet may be provided with a heat-resistant layer.
- liquid electrolyte electrolyte
- electrolyte a solid (gel) electrolyte in which a polymer is added to the electrolyte
- the electrolyte itself can function as a separator. It can be unnecessary.
- the nonaqueous electrolyte injected into the lithium secondary battery can include at least a nonaqueous solvent and a supporting salt.
- a typical example is an electrolytic solution having a composition in which a supporting salt is contained in a suitable non-aqueous solvent.
- non-aqueous solvent examples include ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), 1,2-dimethoxyethane, 1,2- Diethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, 1,3-dioxolane, diethylene glycol dimethyl ether, ethylene glycol dimethyl ether, acetonitrile, propionitrile, nitromethane, N, N-dimethylformamide, dimethyl sulfoxide, sulfolane, ⁇ -butyrolactone
- EC ethylene carbonate
- PC propylene carbonate
- DEC diethyl carbonate
- DMC dimethyl carbonate
- EMC ethyl methyl carbonate
- 1,2-dimethoxyethane 1,2- Diethoxyethane
- tetrahydrofuran 2-
- fluorinated carbonates for example, fluorinated products of carbonates as described above
- a fluorinated cyclic carbonate or a fluorinated chain carbonate can be preferably used.
- fluorinated carbonate having one carbonate structure in one molecule it is preferable to use a fluorinated carbonate having one carbonate structure in one molecule.
- the fluorine substitution rate of the fluorinated carbonate is usually suitably 10% or more, and can be, for example, 20% or more (typically 20% or more and 100% or less, such as 20% or more and 80% or less).
- the fluorinated carbonate preferably exhibits an oxidation potential equal to or higher than the operating potential of the positive electrode active material (vs. Li / Li + ).
- the difference from the operating potential of the positive electrode active material (vs. Li / Li + ) is greater than 0 V (typically about 0.1 V to 3.0 V, preferably 0.2 V to
- the difference is about 2.0V, for example, about 0.3V to 1.0V, the difference is about 0V to 0.3V, and the difference is 0.3V or more (typically 0.3V to 3.V).
- a voltage of about 0 V, preferably about 0.3 V to 2.0 V, for example, about 0.3 V to 1.5 V can be preferably used.
- fluorinated cyclic carbonate those having 2 to 8 carbon atoms (more preferably 2 to 6, for example 2 to 4, typically 2 or 3) are preferable. When there are too many carbon atoms, the viscosity of a non-aqueous electrolyte may become high, or ion conductivity may fall.
- a fluorinated cyclic carbonate represented by the following formula (C1) can be preferably used.
- R 11 , R 12 and R 13 in the above formula (C1) are each independently a hydrogen atom, a fluorine atom or an alkyl group having 1 to 4 carbon atoms (more preferably 1 to 2, typically 1). And haloalkyl groups, and halogen atoms other than fluorine (preferably chlorine atoms).
- the haloalkyl group may be a group having a structure in which one or more hydrogen atoms of the alkyl group are substituted with a halogen atom (for example, a fluorine atom or a chlorine atom, preferably a fluorine atom).
- a compound in which one or two of R 11 , R 12 and R 13 are fluorine atoms is preferred.
- a compound in which at least one of R 12 and R 13 is a fluorine atom is preferable.
- a compound in which R 11 , R 12 and R 13 are all fluorine atoms or hydrogen atoms can be preferably employed.
- fluorinated cyclic carbonate represented by the above formula (C1) include monofluoroethylene carbonate (MFEC), difluoroethylene carbonate, 4,4-difluoroethylene carbonate, trifluoroethylene carbonate, perfluoroethylene carbonate, 4 -Fluoro-4-methylethylene carbonate, 4,5-difluoro-4-methylethylene carbonate, 4-fluoro-5-methylethylene carbonate, 4,4-difluoro-5-methylethylene carbonate, 4- (fluoromethyl)- Ethylene carbonate, 4- (difluoromethyl) -ethylene carbonate, 4- (trifluoromethyl) -ethylene carbonate, 4- (fluoromethyl) -4-fluoroethylene carbonate, 4- (full (Romethyl) -5-fluoroethylene carbonate, 4-fluoro-4,5-dimethylethylene carbonate, 4,5-difluoro-4,5-dimethylethylene carbonate, 4,4-difluoro-5,5-dimethylethylene carbonate
- trans-DFEC trans-difluoroethylene carbonate
- cis-DFEC cis-difluoroethylene carbonate
- a fluorinated chain carbonate represented by the following formula (C2) can be used as the nonaqueous electrolytic solution in the technology disclosed herein.
- At least one (preferably both) of R 21 and R 22 in the formula (C2) is an organic group containing fluorine, and may be, for example, a fluorinated alkyl group or a fluorinated alkyl ether group. It may be a fluorinated alkyl group or a fluorinated alkyl ether group further substituted with a halogen atom other than fluorine.
- One of R 21 and R 22 may be an organic group that does not contain fluorine (for example, an alkyl group or an alkyl ether group).
- Each of R 21 and R 22 is preferably an organic group having 1 to 6 carbon atoms (more preferably 1 to 4, for example 1 to 3, typically 1 or 2).
- R 21 and R 22 are linear, more preferably R 21 and R 22 are both linear.
- a fluorinated chain carbonate in which R 21 and R 22 are both fluorinated alkyl groups and the total number of carbon atoms thereof is 1 or 2 can be preferably used.
- fluorinated chain carbonate represented by the above formula (C2) include fluoromethyl methyl carbonate, difluoromethyl methyl carbonate, trifluoromethyl methyl carbonate, fluoromethyl difluoromethyl carbonate, bis (fluoromethyl) carbonate, bis (Difluoromethyl) carbonate, bis (trifluoromethyl) carbonate, (2-fluoroethyl) methyl carbonate, ethylfluoromethyl carbonate, (2,2-difluoroethyl) methyl carbonate, (2-fluoroethyl) fluoromethyl carbonate, ethyl Difluoromethyl carbonate, (2,2,2-trifluoroethyl) methyl carbonate, (2,2-difluoroethyl) fluoromethyl carbonate, (2-fluoro Ethyl) difluoromethyl carbonate, ethyl trifluoromethyl carbonate, ethyl- (2-fluoroethyl) carbon
- the amount of the fluorinated carbonate is, for example, 2% by volume or more (for example, 5% by volume or more, typical) of all components excluding the supporting salt from the non-aqueous electrolyte (hereinafter also referred to as “component other than the supporting salt”). Is preferably 10% by volume or more.
- the fluorinated carbonate may be substantially 100% by volume (typically 99% by volume or more) of the components other than the supporting salt.
- the amount of fluorinated carbonate is 90% by volume or less (for example, 70% by volume or less, typically, other than the above-mentioned supporting salt). 60% by volume or less) is preferable.
- a dialkyl carbonate having 1 to 4 carbon atoms in an alkyl group for example, DEC
- a fluorinated carbonate for example, DFEC
- a volume ratio of 1: 9 to 9: 1 for example, 3: 7 to 7: 3, typically 4: 6 to 6: 4
- the total amount thereof is 50% by volume or more (for example, 70% by volume or more) of the components other than the above-mentioned supporting salt.
- the supporting salt examples include LiPF 6 , LiBF 4 , LiClO 4 , LiAsF 6 , LiCF 3 SO 3 , LiC 4 F 9 SO 3 , LiN (CF 3 SO 2 ) 2 , LiC (CF 3 SO 2 ) 3 , LiI. 1 type, or 2 or more types of lithium compounds (lithium salt), such as these, can be used.
- the concentration of the supporting salt is not particularly limited, but is about 0.1 mol / L to 5 mol / L (for example, 0.5 mol / L to 3 mol / L, typically 0.8 mol / L to 1.5 mol / L). Concentration.
- the non-aqueous electrolyte (typically non-aqueous electrolyte) preferably contains the above-mentioned silicon-containing cyclic compound from the viewpoint of improving cycle characteristics.
- the content (addition rate) of the silicon-containing cyclic compound in the non-aqueous electrolyte (typically non-aqueous electrolyte) is not particularly limited, but is 0.01% by mass from the viewpoint of obtaining a sufficient cycle characteristic improving effect. It is preferable that it is above (for example, 0.1 mass% or more, typically 0.3 mass% or more).
- the content (addition amount) of the silicon-containing cyclic compound is too large, the disadvantages of the excessive addition exceed the cycle characteristics improving action, and the desired effect tends not to be obtained.
- the non-aqueous electrolyte may contain an optional additive as necessary as long as the object of the present invention is not significantly impaired.
- the additive is used for one or more purposes such as, for example, improving battery output performance, improving storage stability (suppressing capacity reduction during storage, etc.), improving cycle characteristics, improving initial charge / discharge efficiency, etc. Can be done.
- preferable additives include fluorophosphate (preferably difluorophosphate, for example, lithium difluorophosphate represented by LiPO 2 F 2 ), lithium bisoxalate borate (LiBOB), and the like.
- additives such as cyclohexylbenzene and biphenyl which can be used for overcharge countermeasures may be used.
- This method for producing a secondary battery includes preparing a positive electrode and a negative electrode containing a lithium transition metal composite oxide as a positive electrode active material, and supplying a silicon-containing cyclic compound to at least the negative electrode.
- the manufacturing method can include other steps such as, for example, constructing a positive electrode, constructing a negative electrode, and constructing a lithium secondary battery using the positive electrode and the negative electrode. Since it can be performed by appropriately adopting the above-described explanation and the conventionally used technique, it will not be particularly described here.
- the production method disclosed herein includes preparing a positive electrode and a negative electrode containing a lithium transition metal composite oxide as a positive electrode active material. Since the positive electrode and the negative electrode including the positive electrode active material are as described above, description thereof will not be repeated.
- the manufacturing method disclosed herein includes supplying a silicon-containing cyclic compound to at least the negative electrode.
- the silicon-containing cyclic compound and / or the reaction product thereof can be present in the vicinity of the negative electrode, which acts to suppress a decrease in cycle characteristics due to the transition metal eluted from the positive electrode active material.
- the silicon-containing cyclic compound those described above can be preferably used.
- the silicon-containing cyclic compound only needs to be supplied to at least the negative electrode, and may be supplied to other battery components such as the positive electrode. From the viewpoint of efficiently obtaining an effect of improving cycle characteristics, it is particularly preferable to supply the silicon-containing cyclic compound to the negative electrode (typically, supply it intensively to the negative electrode).
- Suitable examples of the supply method include preparing a non-aqueous electrolyte solution containing the silicon-containing cyclic compound, and supplying the prepared non-aqueous electrolyte solution to an electrode body including a positive electrode and a negative electrode.
- the silicon-containing cyclic compound is added to a non-aqueous electrolyte, and the silicon-containing cyclic compound is supplied to an electrode (typically a negative electrode) through the non-aqueous electrolyte.
- the silicon-containing cyclic compound is supplied to the electrode body (typically, the negative electrode) from the non-aqueous electrolyte that can come into contact with the electrode body. Demonstrated.
- the content rate (addition rate) of the silicon-containing cyclic compound in the nonaqueous electrolytic solution is not particularly limited, but is 0.01% by mass or more (for example, 0.1% by mass or more) from the viewpoint of obtaining a sufficient cycle characteristic improving effect. , Typically 0.3% by mass or more). Further, from the viewpoint of suppressing deterioration of battery characteristics (typically increase in resistance) due to excessive addition, it is preferably 5% by mass or less (for example, 2% by mass or less, typically 1% by mass or less). If the content (addition amount) of the silicon-containing cyclic compound is too large, the disadvantages of the excessive addition exceed the cycle characteristics improving action, and the desired effect tends not to be obtained.
- the supply method of the said silicon containing cyclic compound is not limited to the inclusion to the above nonaqueous electrolytes.
- the silicon-containing cyclic compound may be applied to the surface of the positive electrode and / or the negative electrode (typically the negative electrode).
- the method include a method in which a liquid such as water or an organic solvent in which the silicon-containing cyclic compound is dissolved or dispersed is applied to the surface of the electrode (negative electrode) and dried as necessary.
- the silicon-containing cyclic compound may be contained in a composition for forming an electrode mixture layer (preferably a negative electrode mixture layer).
- the amount (addition amount) of the silicon-containing cyclic compound is 0.001 part by mass or more (for example, 0.01 part by mass or more) per 100 parts by mass of the electrode mixture layer (typically the negative electrode mixture layer), (Typically 0.03 parts by mass or more) is preferable. Further, from the viewpoint of suppressing deterioration of battery characteristics due to excessive addition, it is preferably 5 parts by mass or less (for example, 2 parts by mass or less, typically 1 part by mass or less).
- the lithium secondary battery thus constructed can be a lithium secondary battery of 4.2 V class or higher. That is, a lithium secondary battery having a region where the redox potential (operating potential) of the positive electrode active material is 4.2 V or more (vs. Li / Li + ) in the SOC range of 0% to 100% can be obtained. Such a secondary battery can also be grasped as a lithium secondary battery in which the potential of the positive electrode is 4.2 V or more in at least a partial range of SOC 0% to 100%.
- the lithium secondary battery has a lithium secondary battery of 4.3V class or higher (for example, 4.35V class or higher, further 4.5V class or higher). It is preferable to construct as a secondary battery, or a lithium secondary battery of 4.6 V class or higher (for example, 4.8 V class or higher, more preferably 4.9 V class or higher).
- the lithium secondary battery of 4.2 V class or higher in the technology disclosed herein has improved cycle characteristics in high potential charge / discharge, and can be used as a secondary battery for various applications.
- the lithium secondary battery 100 is mounted on a vehicle 1 such as an automobile and can be suitably used as a power source for a drive source such as a motor that drives the vehicle 1. Therefore, the present invention provides a vehicle (typically an automobile, particularly a hybrid automobile (HV), a plug-in hybrid automobile (including a battery pack typically formed by connecting a plurality of series-connected batteries) 100 as a power source.
- PHV hybrid automobile
- EV electric vehicle
- a vehicle equipped with an electric motor such as a fuel cell vehicle
- Example 1 [Production of positive electrode] LiNi 0.5 Mn 1.5 O 4 powder (NiMn spinel) as the positive electrode active material, acetylene black (AB) as the conductive material, and polyvinylidene fluoride (PVDF) as the binder, the mass ratio of these materials was mixed with N-methyl-2-pyrrolidone (NMP) so as to be 85: 10: 5 to prepare a paste-like composition for forming a positive electrode mixture layer.
- NMP N-methyl-2-pyrrolidone
- This composition was uniformly applied to one surface of an aluminum foil (thickness: 15 ⁇ m) so that the amount applied was 6.5 mg / cm 2 (solid content basis). The coated material was dried and pressed, and then cut into a predetermined size (circular shape with a diameter of 14 mm) to obtain a positive electrode.
- a product was prepared. This composition was uniformly applied to one side of a copper foil (thickness: 15 ⁇ m) so that the amount applied was 4.3 mg / cm 2 (based on solid content). The coated material was dried and pressed, and then cut into a predetermined size (circular shape with a diameter of 16 mm) to obtain a negative electrode.
- a coin-type (2032 type) battery 200 having a schematic structure shown in FIG. 4 was produced using the positive electrode and the negative electrode produced as described above. That is, the positive electrode 30 and the negative electrode 40 produced above were laminated together with the separator 50 impregnated with the nonaqueous electrolytic solution 25 and accommodated in the container 80 (negative electrode terminal), and then the electrolytic solution was further dropped. Next, the container 80 was sealed with the gasket 60 and the lid 70 (positive electrode terminal) to obtain the battery 200.
- a polypropylene (PP) porous film having a thickness of 25 ⁇ m cut into a predetermined size (a circle having a diameter of 19 mm) was used.
- non-aqueous electrolyte a 3: 4: 3 (volume ratio) mixed solvent of ethylene carbonate (EC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC) was used, and about 1 mol / L LiPF 6 as a supporting salt.
- electrolytic solution containing 0.5% of 2,4,6,8-tetravinyl-2,4,6,8-tetramethylcyclotetrasiloxane (4VC4S) as a silicon-containing cyclic compound was used. .
- Examples 2 and 3 Coin-type batteries according to Examples 2 and 3 were produced in the same manner as in Example 1 except that the content (addition rate) of the silicon-containing cyclic compound was changed as shown in Table 1.
- Example 4 A coin-type battery according to Example 4 was produced in the same manner as Example 1 except that 4VC4S was not used.
- DFEC difluoroethylene carbonate
- DEC diethyl carbonate
- Example 9 A coin-type battery according to Example 9 was produced in the same manner as Example 8 except that 4VC4S was not used.
- Example 10 A coin-type battery according to Example 10 was produced in the same manner as in Example 1 except that the silicon-containing cyclic compound was changed from 4VC4S to 2,4,6-trivinyl-2,4,6-trimethylcyclotrisiloxane (3VC3S).
- Example 1 Each of the batteries according to Example 4 and Example 10 was subjected to the same test as the capacity retention rate measurement test after 100 cycles. The results are shown in Table 2.
- Example 11 A positive electrode was produced in the same manner as in Example 1 except that LiMn 2 O 4 powder (Mn spinel) was used instead of NiMn spinel as the positive electrode active material, and a coin-type battery according to Example 11 was produced.
- LiMn 2 O 4 powder Mn spinel
- Example 12 A coin-type battery according to Example 12 was produced in the same manner as Example 11 except that 4VC4S was not used.
- Example 13 A positive electrode was produced in the same manner as in Example 1 except that LiMnPO 4 powder (Mn olivine) was used instead of NiMn spinel as the positive electrode active material, and a coin-type battery according to Example 13 was produced.
- LiMnPO 4 powder Mn olivine
- Example 14 A coin-type battery according to Example 14 was made in the same manner as Example 13 except that 4VC4S was not used.
- Example 15 A positive electrode was produced in the same manner as in Example 1 except that LiNi 1/3 Co 1/3 Mn 1/3 O 2 powder (NiCoMn layered) was used as the positive electrode active material instead of NiMn spinel. A type battery was produced.
- Example 16 A coin-type battery according to Example 16 was made in the same manner as Example 15 except that 4VC4S was not used.
- Example 17 A coin-type battery according to Example 17 was obtained in the same manner as in Example 1 except that the silicon-containing cyclic compound was changed from 4VC4S to 2,2,4,4,6,6,8,8-octavinylcyclotetrasiloxane (8VC4S). Produced.
- AC impedance measurement The battery according to Example 17 was subjected to AC impedance measurement of the battery adjusted to the SOC 60% after the conditioning (before the cycle test). For comparison, the same tests were performed on the batteries according to Examples 1 and 4. The results are shown in FIG.
- the AC impedance measurement conditions were a frequency range of 1 MHz to 0.1 Hz and a voltage amplitude of 5 mV.
- the batteries according to Examples 1 to 3 using a cyclic siloxane having a vinyl group as an additive were used in Examples 4 to 7 in which no cyclic siloxane having a vinyl group was used.
- the capacity maintenance rate after 100 cycles was higher than that of the battery according to.
- a siloxane satisfying only one of the vinyl group content and the cyclic structure was used as an additive, but the cycle characteristics were the same as or lower than those of Example 4 in which no additive was used.
- the battery according to Example 10 using a cyclic siloxane having a vinyl group different from that in Example 1 as an additive also improved cycle characteristics although it did not reach Example 1.
- the battery according to Example 17 using a silicon-containing compound having a high vinyl group substitution rate (typically, a cyclic siloxane in which all substituents bonded to silicon atoms are vinyl groups)
- the initial resistance was lower than that of the battery according to Example 1 while showing the capacity retention rate after 100 cycles equivalent to Example 1. From these results, it can be seen that by using a silicon-containing compound having a high vinyl group substitution rate, the initial resistance can be suppressed while realizing high cycle characteristics.
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Inorganic Chemistry (AREA)
- Materials Engineering (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Physics & Mathematics (AREA)
- Composite Materials (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Secondary Cells (AREA)
Abstract
Description
本出願は、2012年7月17日に出願された日本国特許出願2012-158487号に基づく優先権を主張しており、その出願の全内容は本明細書中に参照として組み入れられている。
好ましい正極活物質として、上記一般式(A1)におけるMが少なくともNiを含む化合物、例えば、次の一般式(A2):LiNipM1 qMn2-p-qO4;で表されるスピネル構造のリチウム遷移金属複合酸化物が挙げられる。ここで、0<pであり、0≦qであり、p+q<2(典型的にはp+q≦1)である。好ましい一態様では、q=0であり、0.2≦p≦0.6である。上記の含有割合(上記一般式(A2)のpで示す割合)のNiを含有させることによって、スピネル構造のLiNiMn複合酸化物(例えばLiNi0.5Mn1.5O4)の充電終止時の正極電位を高電位化(典型的には4.5V(対Li/Li+)以上に高電位化)させることができ、5V級のリチウム二次電池を構築することが可能になる。上記一般式(A2)において、0<qである場合、M1は、Ni,Mn以外の任意の金属元素または非金属元素(例えば、Fe,Co,Cu,Cr,ZnおよびAlから選択される1種または2種以上)であり得る。M1が3価のFeおよびCoの少なくとも一方を含むことが好ましい。また、0<q≦0.3であり、1≦2p+qであることが好ましい。
(3)一般式Li2MO3で表されるリチウム遷移金属複合酸化物。ここで、Mは、Mn,Fe,Co等の遷移金属元素の少なくとも1種を含み、他の金属元素または非金属元素をさらに含み得る。具体例としては、Li2MnO3,Li2PtO3等が挙げられる。
(4)一般式LiMPO4で表されるリチウム遷移金属化合物(リン酸塩)。ここで、Mは、Mn,Fe,Ni,Co等の遷移金属元素の少なくとも1種を含み、他の金属元素または非金属元素をさらに含み得る。具体例としては、LiMnPO4,LiFePO4等が挙げられる。
(5)一般式Li2MPO4Fで表されるリチウム遷移金属化合物(リン酸塩)。ここで、Mは、Mn,Ni,Co等の遷移金属元素の少なくとも1種を含み、他の金属元素または非金属元素をさらに含み得る。具体例としては、Li2MnPO4F等が挙げられる。
(6)LiMO2とLi2MO3との固溶体。ここで、LiMO2は上記(2)に記載の一般式で表される組成を指し、Li2MO3は上記(3)に記載の一般式で表される組成を指す。具体例としては、0.5LiNi1/3Mn1/3Co1/3O2-0.5Li2MnO3で表される固溶体が挙げられる。
[正極の作製]
正極活物質としてLiNi0.5Mn1.5O4粉末(NiMnスピネル)と、導電材としてアセチレンブラック(AB)と、結着材としてポリフッ化ビニリデン(PVDF)とを、これらの材料の質量比が85:10:5となるようにN-メチル-2-ピロリドン(NMP)で混合して、ペースト状の正極合材層形成用組成物を調製した。この組成物を、アルミニウム箔(厚さ15μm)の片面に塗付量が6.5mg/cm2(固形分基準)となるように均一に塗付した。その塗付物を乾燥させ、プレスした後、所定サイズ(直径14mmの円形)に切り出して正極を得た。
負極活物質としてグラファイト粉末と、結着材としてPVDFとを、これらの材料の質量比が92.5:7.5となるようにNMPで混合して、ペースト状の負極合材層形成用組成物を調製した。この組成物を、銅箔(厚さ15μm)の片面に塗付量が4.3mg/cm2(固形分基準)となるように均一に塗付した。その塗付物を乾燥させ、プレスした後、所定サイズ(直径16mmの円形)に切り出して負極を得た。
上記のようにして作製した正極と負極とを用いて、図4に示す概略構造のコイン型(2032型)電池200を作製した。すなわち、上記で作製した正極30および負極40を、非水電解液25を含浸させたセパレータ50とともに積層し、容器80(負極端子)に収容した後、さらに同電解液を滴下した。次いで、ガスケット60および蓋70(正極端子)で容器80を封止して、電池200を得た。セパレータとしては、厚み25μmのポリプロピレン(PP)製多孔質フィルムを所定サイズ(直径19mmの円形)に切り出したものを使用した。非水電解液としては、エチレンカーボネート(EC)とエチルメチルカーボネート(EMC)とジメチルカーボネート(DMC)との3:4:3(体積比)混合溶媒に、支持塩として約1mol/LのLiPF6を溶解し、さらにケイ素含有環状化合物として2,4,6,8-テトラビニル-2,4,6,8-テトラメチルシクロテトラシロキサン(4VC4S)0.5%を含有させた電解液を用いた。
ケイ素含有環状化合物の含有率(添加率)を表1に示すように代えた他は例1と同様にして例2,3に係るコイン型電池を作製した。
4VC4Sを用いなかった他は例1と同様にして例4に係るコイン型電池を作製した。
4VC4Sを表1に示す添加剤に代えた他は例1と同様にして例5~7に係るコイン型電池を作製した。
非水電解液の非水溶媒として、EC:EMC:DMC=3:4:3(体積比)の混合溶媒に代えてジフルオロエチレンカーボネート(DFEC)とジエチルカーボネート(DEC)との1:1(体積比)混合溶媒を用いた他は例1と同様にして例8に係るコイン型電池を作製した。
4VC4Sを用いなかった他は例8と同様にして例9に係るコイン型電池を作製した。
上記で得られた各電池に対して、温度25℃にて、1/10Cのレートで4.1Vまで充電する操作と、同じレートで3.0Vまで放電させる操作とを交互に3回繰り返した。次いで、60℃の温度環境において、4.9Vまでの定電流定電圧(CCCV)充電(1Cレート、0.15Cカット)と、3.5Vまでの定電流(CC)放電(1Cレート)とを100サイクル繰り返した(サイクル試験)。1サイクル目の放電容量(初期放電容量)を100%として、100サイクル後の放電容量の維持率(%)を求めた。得られた結果を表1に示す。また、例1と例4については、サイクル数と容量維持率(%)との関係を図5に示す。
ケイ素含有環状化合物を4VC4Sから2,4,6-トリビニル-2,4,6-トリメチルシクロトリシロキサン(3VC3S)に代えた他は例1と同様にして例10に係るコイン型電池を作製した。
正極活物質として、NiMnスピネルに代えてLiMn2O4粉末(Mnスピネル)を用いた他は例1と同様にして正極を作製し、例11に係るコイン型電池を作製した。
4VC4Sを用いなかった他は例11と同様にして例12に係るコイン型電池を作製した。
例11および12に係る電池に対して、温度25℃にて、1/10Cのレートで4.1Vまで充電する操作と、同じレートで3.0Vまで放電させる操作とを交互に3回繰り返した。次いで、60℃の温度環境において、4.9VまでのCCCV充電(1Cレート、0.15Cカット)と、3.0VまでのCC放電(1Cレート)とを50サイクル繰り返した(サイクル試験)。1サイクル目の放電容量(初期放電容量)を100%として、50サイクル後の放電容量の維持率(%)を求めた。得られた結果を表3に示す。
また、例11および12に係る電池に対して、温度25℃にて、1/10Cのレートで4.1Vまで充電する操作と、同じレートで3.0Vまで放電させる操作とを交互に3回繰り返した。次いで、60℃の温度環境において、4.2VまでのCCCV充電(1Cレート、0.15Cカット)と、3.0VまでのCC放電(1Cレート)とを100サイクル繰り返した(サイクル試験)。1サイクル目の放電容量(初期放電容量)を100%として、100サイクル後の放電容量の維持率(%)を求めた。得られた結果を表3に示す。また、サイクル数と容量維持率(%)との関係を図6に示す。
正極活物質として、NiMnスピネルに代えてLiMnPO4粉末(Mnオリビン)を用いた他は例1と同様にして正極を作製し、例13に係るコイン型電池を作製した。
4VC4Sを用いなかった他は例13と同様にして例14に係るコイン型電池を作製した。
例13および14に係る電池に対して、温度25℃にて、1/10Cのレートで4.1Vまで充電する操作と、同じレートで3.0Vまで放電させる操作とを交互に3回繰り返した。次いで、60℃の温度環境において、4.8VまでのCCCV充電(1Cレート、0.15Cカット)と、2.0VまでのCC放電(1Cレート)とを100サイクル繰り返した(サイクル試験)。1サイクル目の放電容量(初期放電容量)を100%として、100サイクル後の放電容量の維持率(%)を求めた。得られた結果を表4に示す。
正極活物質として、NiMnスピネルに代えてLiNi1/3Co1/3Mn1/3O2粉末(NiCoMn層状)を用いた他は例1と同様にして正極を作製し、例15に係るコイン型電池を作製した。
4VC4Sを用いなかった他は例15と同様にして例16に係るコイン型電池を作製した。
例15および16に係る電池に対して、温度25℃にて、1/10Cのレートで4.1Vまで充電する操作と、同じレートで3.0Vまで放電させる操作とを交互に3回繰り返した。次いで、60℃の温度環境において、4.6VまでのCCCV充電(1Cレート、0.15Cカット)と、3.0VまでのCC放電(1Cレート)とを100サイクル繰り返した(サイクル試験)。1サイクル目の放電容量(初期放電容量)を100%として、100サイクル後の放電容量の維持率(%)を求めた。得られた結果を表5に示す。
ケイ素含有環状化合物を4VC4Sから2,2,4,4,6,6,8,8-オクタビニルシクロテトラシロキサン(8VC4S)に代えた他は例1と同様にして例17に係るコイン型電池を作製した。
上記で得られた例17に係る電池に対して、温度25℃にて、1/10Cのレートで4.1Vまで充電する操作と、同じレートで3.0Vまで放電させる操作とを交互に3回繰り返した(コンディショニング)。次いで、60℃の温度環境において、4.9Vまでの定電流定電圧(CCCV)充電(1Cレート、0.15Cカット)と、3.5Vまでの定電流(CC)放電(1Cレート)とを100サイクル繰り返した(サイクル試験)。1サイクル目の放電容量(初期放電容量)を100%として、100サイクル後の放電容量の維持率(%)を求めた。得られた結果を表1に示す。対比のため、例1,4に係る電池に対しても同様の試験を行った。結果を表6に示す。
例17に係る電池について、上記コンディショニング後にSOC60%の充電状態に調整したもの(サイクル試験前)の交流インピーダンス測定を行った。対比のため、例1,4に係る電池に対しても同様の試験を行った。結果を図8に示す。交流インピーダンス測定条件は、周波数範囲1MHz~0.1Hz、電圧振幅5mVとした。
10 電池ケース
12 開口部
14 蓋体
20 捲回電極体
25 非水電解質(非水電解液)
30 正極(正極シート)
32 正極集電体
34 正極合材層
35 正極集電体積層部
36 正極合材層非形成部
37 内部正極端子
38 外部正極端子
40 負極(負極シート)
42 負極集電体
44 負極合材層
45 負極集電体積層部
46 負極合材層非形成部
47 内部負極端子
48 外部負極端子
50,50A,50B セパレータ(セパレータシート)
100 リチウム二次電池
Claims (12)
- 正極活物質としてリチウム遷移金属複合酸化物を用いる4.2V級以上のリチウム二次電池であって、
前記リチウム二次電池を構成する負極の近傍には、ケイ素含有環状化合物および/またはその反応生成物が存在しており、
前記ケイ素含有環状化合物は、環を構成する原子の少なくとも1つがケイ素原子であり、かつ少なくとも1つのビニル基を有する、リチウム二次電池。 - 前記ケイ素含有環状化合物は、環を構成するケイ素原子に結合した置換基がすべてビニル基である、請求項1または2に記載のリチウム二次電池。
- 前記正極活物質は、Liと、遷移金属元素としてNiおよびMnと、を含むスピネル構造のリチウム遷移金属複合酸化物である、請求項1~3のいずれか一項に記載のリチウム二次電池。
- 前記リチウム二次電池は非水電解質を含み、該非水電解質は、非水溶媒としてフッ素化カーボネートを含む、請求項1~4のいずれか一項に記載のリチウム二次電池。
- 4.2V級以上のリチウム二次電池を製造する方法であって、
正極活物質としてリチウム遷移金属複合酸化物を含む正極と負極とを用意すること、および
少なくとも前記負極にケイ素含有環状化合物を供給すること、を包含し、
前記ケイ素含有環状化合物は、環を構成する原子の少なくとも1つがケイ素原子であり、かつ少なくとも1つのビニル基を有する、リチウム二次電池の製造方法。 - 前記ケイ素含有環状化合物の供給は、
前記ケイ素含有環状化合物を含む非水電解質を用意すること、および
前記用意した非水電解質を、前記正極と前記負極とを備える電極体に供給すること、を包含する、請求項6に記載のリチウム二次電池の製造方法。 - 前記ケイ素含有環状化合物は、環を構成するケイ素原子に結合した置換基がすべてビニル基である、請求項6~8のいずれか一項に記載のリチウム二次電池の製造方法。
- 前記正極活物質として、Liと、遷移金属元素としてNiおよびMnと、を含むスピネル構造のリチウム遷移金属複合酸化物を用いる、請求項6~9のいずれか一項に記載のリチウム二次電池の製造方法。
- 前記リチウム二次電池は非水電解質を含み、該非水電解質の非水溶媒として、フッ素化カーボネートを用いる、請求項7に記載のリチウム二次電池の製造方法。
- 請求項1~5のいずれか一項に記載のリチウム二次電池を搭載した車両。
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR1020157003823A KR20150034261A (ko) | 2012-07-17 | 2013-06-26 | 리튬 이차 전지 및 그 제조 방법 |
JP2014525770A JP6032504B2 (ja) | 2012-07-17 | 2013-06-26 | リチウム二次電池およびその製造方法 |
CN201380037311.9A CN104471778A (zh) | 2012-07-17 | 2013-06-26 | 锂二次电池及其制造方法 |
US14/409,870 US9793547B2 (en) | 2012-07-17 | 2013-06-26 | Lithium secondary battery and method for producing same |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2012158487 | 2012-07-17 | ||
JP2012-158487 | 2012-07-17 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2014013850A1 true WO2014013850A1 (ja) | 2014-01-23 |
Family
ID=49948684
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2013/067465 WO2014013850A1 (ja) | 2012-07-17 | 2013-06-26 | リチウム二次電池およびその製造方法 |
Country Status (5)
Country | Link |
---|---|
US (1) | US9793547B2 (ja) |
JP (1) | JP6032504B2 (ja) |
KR (1) | KR20150034261A (ja) |
CN (1) | CN104471778A (ja) |
WO (1) | WO2014013850A1 (ja) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPWO2016147872A1 (ja) * | 2015-03-17 | 2018-01-25 | 株式会社Adeka | 非水電解液及び非水電解液二次電池 |
JP2018120711A (ja) * | 2017-01-24 | 2018-08-02 | 株式会社Gsユアサ | 非水電解質、蓄電素子及び蓄電素子の製造方法 |
CN110767939A (zh) * | 2019-10-18 | 2020-02-07 | 宁德时代新能源科技股份有限公司 | 用于锂离子电池的电解液、锂离子电池、电池模块、电池包及装置 |
Families Citing this family (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE112018001059T5 (de) * | 2017-02-28 | 2019-11-14 | Seeo, Inc. | Polare cyclosiloxane als hochspannungsstabile elektrolyte für lithium-batterien |
KR102290957B1 (ko) | 2017-03-31 | 2021-08-20 | 주식회사 엘지에너지솔루션 | 이차전지용 바인더 조성물, 이를 포함하는 이차전지용 전극 및 리튬 이차전지 |
CN109411814B (zh) * | 2017-08-18 | 2021-07-30 | 宁德时代新能源科技股份有限公司 | 一种电解液以及电池 |
CN107910591B (zh) * | 2017-11-14 | 2019-12-10 | 石家庄圣泰化工有限公司 | 一种耐高温锂电池电解液 |
US10978752B2 (en) | 2018-03-19 | 2021-04-13 | Kabushiki Kaisha Toshiba | Secondary battery, battery pack, and vehicle |
CN109004279A (zh) * | 2018-07-18 | 2018-12-14 | 石家庄圣泰化工有限公司 | 环状硅酸酯化合物于电池电解液中的应用 |
JP7019062B2 (ja) * | 2018-09-14 | 2022-02-14 | 旭化成株式会社 | 非水系電解液及び非水系二次電池 |
KR20200045641A (ko) | 2018-10-23 | 2020-05-06 | 윤용산 | 1-자유도 변속 레버로 작동되는 수동변속기 |
US11165099B2 (en) * | 2018-12-21 | 2021-11-02 | Enevate Corporation | Silicon-based energy storage devices with cyclic organosilicon containing electrolyte additives |
CN113839093A (zh) * | 2021-09-16 | 2021-12-24 | 湖州昆仑亿恩科电池材料有限公司 | 一种锂离子电池非水电解液及其应用 |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005051192A (ja) * | 2002-11-28 | 2005-02-24 | Tosoh Corp | 有機シラン、有機シロキサン化合物を含んでなる絶縁膜用材料、その製造方法および半導体デバイス |
JP2010503175A (ja) * | 2006-09-07 | 2010-01-28 | エルジー・ケム・リミテッド | ゲル状ポリマー電解質及びこれを備えた電気化学デバイス |
Family Cites Families (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5830600A (en) * | 1996-05-24 | 1998-11-03 | Sri International | Nonflammable/self-extinguishing electrolytes for batteries |
US6350543B2 (en) * | 1999-12-29 | 2002-02-26 | Kimberly-Clark Worldwide, Inc. | Manganese-rich quaternary metal oxide materials as cathodes for lithium-ion and lithium-ion polymer batteries |
JP4154951B2 (ja) * | 2002-08-08 | 2008-09-24 | 三菱化学株式会社 | 非水電解液二次電池 |
US7790316B2 (en) * | 2004-03-26 | 2010-09-07 | Shin-Etsu Chemical Co., Ltd. | Silicon composite particles, preparation thereof, and negative electrode material for non-aqueous electrolyte secondary cell |
WO2007055087A1 (ja) | 2005-10-20 | 2007-05-18 | Mitsubishi Chemical Corporation | リチウム二次電池及びそれに用いる非水系電解液 |
CN101292389B (zh) * | 2005-10-20 | 2010-09-22 | 三菱化学株式会社 | 锂二次电池以及其中使用的非水电解液 |
JP2007227367A (ja) * | 2006-01-27 | 2007-09-06 | Mitsubishi Chemicals Corp | リチウムイオン二次電池 |
JP5671775B2 (ja) | 2006-01-27 | 2015-02-18 | 三菱化学株式会社 | リチウムイオン二次電池 |
JP5004495B2 (ja) * | 2006-04-17 | 2012-08-22 | 株式会社デンソー | 非水電解液および該電解液を用いた二次電池 |
JP2009054286A (ja) * | 2007-08-23 | 2009-03-12 | Sony Corp | 電解液および電池 |
JP2009054287A (ja) * | 2007-08-23 | 2009-03-12 | Sony Corp | 電解液および電池 |
JP5245404B2 (ja) | 2007-12-28 | 2013-07-24 | ダイキン工業株式会社 | 非水系電解液 |
JP2010044883A (ja) | 2008-08-08 | 2010-02-25 | Mitsui Chemicals Inc | 非水電解液及びリチウム二次電池 |
JP2011034943A (ja) | 2009-03-16 | 2011-02-17 | Sanyo Electric Co Ltd | 非水電解液二次電池 |
-
2013
- 2013-06-26 JP JP2014525770A patent/JP6032504B2/ja active Active
- 2013-06-26 CN CN201380037311.9A patent/CN104471778A/zh active Pending
- 2013-06-26 KR KR1020157003823A patent/KR20150034261A/ko not_active Application Discontinuation
- 2013-06-26 WO PCT/JP2013/067465 patent/WO2014013850A1/ja active Application Filing
- 2013-06-26 US US14/409,870 patent/US9793547B2/en active Active
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005051192A (ja) * | 2002-11-28 | 2005-02-24 | Tosoh Corp | 有機シラン、有機シロキサン化合物を含んでなる絶縁膜用材料、その製造方法および半導体デバイス |
JP2010503175A (ja) * | 2006-09-07 | 2010-01-28 | エルジー・ケム・リミテッド | ゲル状ポリマー電解質及びこれを備えた電気化学デバイス |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPWO2016147872A1 (ja) * | 2015-03-17 | 2018-01-25 | 株式会社Adeka | 非水電解液及び非水電解液二次電池 |
JP2018120711A (ja) * | 2017-01-24 | 2018-08-02 | 株式会社Gsユアサ | 非水電解質、蓄電素子及び蓄電素子の製造方法 |
CN110767939A (zh) * | 2019-10-18 | 2020-02-07 | 宁德时代新能源科技股份有限公司 | 用于锂离子电池的电解液、锂离子电池、电池模块、电池包及装置 |
CN110767939B (zh) * | 2019-10-18 | 2021-06-11 | 宁德时代新能源科技股份有限公司 | 用于锂离子电池的电解液、锂离子电池、电池模块、电池包及装置 |
Also Published As
Publication number | Publication date |
---|---|
JP6032504B2 (ja) | 2016-11-30 |
KR20150034261A (ko) | 2015-04-02 |
US20150188141A1 (en) | 2015-07-02 |
CN104471778A (zh) | 2015-03-25 |
US9793547B2 (en) | 2017-10-17 |
JPWO2014013850A1 (ja) | 2016-06-30 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP6032504B2 (ja) | リチウム二次電池およびその製造方法 | |
JP6048726B2 (ja) | リチウム二次電池およびその製造方法 | |
JP6041343B2 (ja) | リチウム二次電池およびその製造方法 | |
JP5858295B2 (ja) | 非水電解質二次電池 | |
CN109494354B (zh) | 非水电解液二次电池 | |
JP5999457B2 (ja) | リチウム二次電池およびその製造方法 | |
WO2013058033A1 (ja) | 非水電解液二次電池及びその製造方法 | |
JP2015103332A (ja) | 非水電解液二次電池 | |
WO2014038245A1 (ja) | 非水電解液二次電池の製造方法 | |
JP2017016751A (ja) | リチウムイオン二次電池及び電解液 | |
JP6120101B2 (ja) | 非水電解質二次電池およびその製造方法 | |
JP2014093158A (ja) | リチウムイオン二次電池 | |
JP2020119867A (ja) | リチウム二次電池用非水電解液 | |
JP6120068B2 (ja) | 非水電解液二次電池の製造方法 | |
JP7290087B2 (ja) | 非水電解液二次電池 | |
JP7290089B2 (ja) | 非水電解液二次電池 | |
JP2019021516A (ja) | 非水電解液二次電池 | |
JP7265697B2 (ja) | 非水系リチウム二次電池の負極材料 | |
JP2018190624A (ja) | 非水電解質二次電池 | |
JP2015011843A (ja) | 非水電解液二次電池 | |
JP2022176583A (ja) | 非水電解液および該非水電解液を用いた二次電池 | |
JP2021125377A (ja) | 非水電解液二次電池 | |
CN113054255A (zh) | 非水电解液和非水电解液二次电池 | |
JP2018097945A (ja) | リチウムイオン二次電池 | |
JP2018101493A (ja) | リチウムイオン二次電池 |
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: 13820513 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 14409870 Country of ref document: US |
|
ENP | Entry into the national phase |
Ref document number: 2014525770 Country of ref document: JP Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
ENP | Entry into the national phase |
Ref document number: 20157003823 Country of ref document: KR Kind code of ref document: A |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 13820513 Country of ref document: EP Kind code of ref document: A1 |