WO2019064728A1 - Matériau actif d'électrode négative contenant un matériau de silicium contenant de l'oxygène, et son procédé de production - Google Patents

Matériau actif d'électrode négative contenant un matériau de silicium contenant de l'oxygène, et son procédé de production Download PDF

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WO2019064728A1
WO2019064728A1 PCT/JP2018/023079 JP2018023079W WO2019064728A1 WO 2019064728 A1 WO2019064728 A1 WO 2019064728A1 JP 2018023079 W JP2018023079 W JP 2018023079W WO 2019064728 A1 WO2019064728 A1 WO 2019064728A1
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oxygen
negative electrode
containing silicon
silicon material
electrode active
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PCT/JP2018/023079
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English (en)
Japanese (ja)
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泰弘 山口
彩人 井山
敬史 毛利
正則 原田
裕介 渡邉
弘樹 大島
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株式会社豊田自動織機
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Priority claimed from JP2018023432A external-priority patent/JP6852691B2/ja
Application filed by 株式会社豊田自動織機 filed Critical 株式会社豊田自動織機
Publication of WO2019064728A1 publication Critical patent/WO2019064728A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B33/00—Silicon; Compounds thereof
    • C01B33/113—Silicon oxides; Hydrates thereof
    • 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
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • 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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a negative electrode active material containing an oxygen-containing silicon material.
  • Silicon is known to be used as a component of semiconductors, solar cells, secondary batteries and the like, and hence research on silicon is actively conducted.
  • Patent Document 1 discloses that a layered silicon compound mainly composed of layered polysilane from which CaSi 2 is reacted with an acid to remove Ca is synthesized, and the layered silicon compound is heated at 300 ° C. or higher to generate hydrogen.
  • a lithium ion secondary battery is described which has produced a detached silicon material and which comprises the silicon material as a negative electrode active material.
  • the present invention has been made in view of such circumstances, and it is an object of the present invention to provide a negative electrode active material containing a silicon material and a method of manufacturing the same, which can optimize the capacity retention rate of a secondary battery.
  • the inventor repeated trial and error and examined a method of manufacturing a silicon material. As a result, it has been found that a secondary battery employing a silicon material containing an element other than silicon to some extent is excellent in capacity retention rate.
  • the present invention relates to an oxygen-containing silicon material focusing on oxygen as an element other than silicon, and in particular, to provide a manufacturing method capable of controlling the oxygen content of the oxygen-containing silicon material.
  • the negative electrode active material of the present invention has an oxygen mass% (W 2 O %) of 16 ⁇ W 2 O ⁇ 27 and an silicon mass% (W Si %) of 62 ⁇ W Si ⁇ 81 (hereinafter referred to as And the oxygen-containing silicon material of the present invention).
  • One embodiment of a method for producing a negative electrode active material containing the oxygen-containing silicon material of the present invention is a-1) reacting CaSi 2 with an aqueous acid solution at 15 to 50 ° C. to synthesize an oxygen-containing layered silicon compound containing layered polysilane, b) heating the oxygen-containing layered silicon compound at 300 ° C. or higher to synthesize an oxygen-containing silicon material; It is characterized by including.
  • Another aspect of the method for producing a negative electrode active material containing the oxygen-containing silicon material of the present invention is a-2-1) reacting CaSi 2 with an aqueous acid solution at ⁇ 20 to 10 ° C., a-2-2) a step of synthesizing an oxygen-containing layered silicon compound containing layered polysilane with the temperature of the reaction liquid being set to 15 to 50 ° C., following the above step a-2-1), b) heating the oxygen-containing layered silicon compound at 300 ° C. or higher to synthesize an oxygen-containing silicon material; It is characterized by including.
  • a negative electrode active material containing an oxygen-containing silicon material and a method for producing the same, which can optimize the capacity retention rate of a secondary battery.
  • FIG. 1 It is a graph which shows the relationship of the integral capacity and discharge capacity of each lithium ion secondary battery in evaluation example 2.
  • FIG. It is a graph which shows the relationship of the integral capacity and discharge capacity of each lithium ion secondary battery in evaluation example 9.
  • FIG. 1 It is a graph which shows the relationship of the integral capacity and discharge capacity of each lithium ion secondary battery in evaluation example 9.
  • the numerical range “ab” described in the present specification includes the lower limit a and the upper limit b in that range. And a numerical range can be constituted by combining these arbitrarily including the upper limit and lower limit, and the numerical value listed in the example. Furthermore, numerical values arbitrarily selected from these numerical ranges can be used as new upper and lower numerical values.
  • the negative electrode active material of the present invention contains an oxygen-containing silicon material in which oxygen mass% (W 2 O %) is 16 ⁇ W 2 O ⁇ 27 and silicon mass% (W Si %) is 62 ⁇ W Si ⁇ 81. It is characterized by
  • the oxygen-containing silicon material of the present invention can be used as a negative electrode active material of a secondary battery such as a lithium ion secondary battery. Since the oxygen-containing silicon material of the present invention has an appropriate ratio of oxygen to silicon, the secondary battery comprising the oxygen-containing silicon material of the present invention satisfies all of the capacity retention rate, capacity, and initial efficiency in a well-balanced manner. .
  • An oxygen-containing silicon material having an excessively low oxygen mass% and an excessively high silicon mass% is excellent in capacity and initial efficiency as a negative electrode active material, but is inferior in capacity retention rate.
  • an oxygen-containing silicon material having an excessively high oxygen content by mass and an excessively low silicon content by mass is inferior in capacity and initial efficiency as a negative electrode active material.
  • Oxygen mass% in the oxygen-containing silicon material of the present invention is preferably 16.5 ⁇ W O ⁇ 26.5, and more preferably 17 ⁇ W O ⁇ 26, is 18 ⁇ W O ⁇ 25.5 More preferably, 19 ⁇ W o ⁇ 25 is particularly preferred.
  • the silicon mass% (W Si %) in the oxygen-containing silicon material of the present invention preferably satisfies 65 ⁇ W Si ⁇ 80, more preferably 68 ⁇ W Si ⁇ 79, and 70 ⁇ W Si ⁇ It is further preferable to satisfy 78, and it is particularly preferable to satisfy 70 ⁇ W Si ⁇ 76.
  • the oxygen-containing silicon material of the present invention may contain elements other than oxygen and silicon. As such an element, Al is preferable.
  • the oxygen-containing silicon material of the present invention containing Al has a reduced resistance. Therefore, it can be said that the oxygen-containing silicon material of the present invention containing Al is excellent in the function as a negative electrode active material.
  • oxygen having a stable Al—O bond can be said to be less likely to be involved in the oxidation of silicon which is more electronegative than Al. Therefore, a secondary battery having the oxygen-containing silicon material of the present invention containing Al as a negative electrode active material can be expected to have a long life.
  • Al mass% (W Al %) in the oxygen-containing silicon material of the present invention satisfy 0 ⁇ W Al ⁇ 1, and more preferably 0 ⁇ W Al ⁇ 0.8. It is further preferable to satisfy ⁇ W Al ⁇ 0.6, and it is particularly preferable to satisfy 0.05 ⁇ W Al ⁇ 0.4.
  • the oxygen-containing silicon material of the present invention may contain an impurity derived from a manufacturing process or an impurity derived from a raw material.
  • an acid is used in the method for producing an oxygen-containing silicon material of the present invention.
  • the element derived from the anion of the acid is likely to be contained as an impurity in the oxygen-containing silicon material of the present invention.
  • the element mass% (W x %) derived from the acid anion is preferably a small value. When W x % is large, the irreversible capacity of the oxygen-containing silicon material is increased, thereby reducing the initial efficiency. As a range of W x %, 0 ⁇ W x ⁇ 8 can be illustrated.
  • the range of W x % preferably satisfies 0 ⁇ W x ⁇ 6, more preferably 0 ⁇ W x ⁇ 4, and still more preferably 0 ⁇ W x ⁇ 3. It is particularly preferred to satisfy W x ⁇ 2.
  • the element mass% (W x %) derived from the acid anion is read as halogen mass% (W x %).
  • impurities that can be contained in the oxygen-containing silicon material of the present invention include Ca and Fe.
  • Ca is derived from the raw material CaSi 2 .
  • Fe is an impurity in the raw material.
  • the Ca mass% (W Ca %) in the oxygen-containing silicon material of the present invention is preferably a small value.
  • Ca mass% in the oxygen-containing silicon material of the present invention (W Ca%) is preferably satisfies 0 ⁇ W Ca ⁇ 5, more preferably satisfies 0 ⁇ W Ca ⁇ 1, 0 ⁇ W Ca ⁇ It is further preferable to satisfy 0.5, and it is particularly preferable to satisfy 0 ⁇ W Ca ⁇ 0.3. In view of easiness of mixing and removal of Ca , it is assumed that Ca mass% (W Ca %) in the oxygen-containing silicon material of the present invention is 0 ⁇ W Ca.
  • the Fe mass% (W 2 Fe %) in the oxygen-containing silicon material of the present invention is preferably a small value.
  • Fe wt% in the oxygen-containing silicon material of the present invention (W Fe%) is preferably satisfies 0 ⁇ W Fe ⁇ 3, more preferably satisfies 0 ⁇ W Fe ⁇ 1, 0 ⁇ W Fe ⁇ It is more preferable to satisfy 0.5, particularly preferably to satisfy 0 ⁇ W Fe ⁇ 0.3, and most preferably to satisfy 0 ⁇ W Fe ⁇ 0.1.
  • Fe mass% (W 2 Fe %) in the Al-containing silicon material of the present invention is 0 ⁇ W 2 Fe .
  • the relationship of Al mass% (W Al %) and Fe mass% (W Fe %) satisfies W Al > W Fe, and more preferably W Al > 2 ⁇ W Fe .
  • the oxygen-containing silicon material of the present invention preferably has a structure in which a plurality of plate-like silicon bodies are stacked in the thickness direction. This laminated structure can be confirmed by observation with a scanning electron microscope or the like.
  • the plate-like silicon body has a thickness of 10 nm for efficient insertion and desorption reaction of lithium ions. Those in the range of ⁇ 100 nm are preferable, and those in the range of 20 nm to 50 nm are more preferable.
  • the length of the plate-like silicon body in the long axis direction is preferably in the range of 0.1 ⁇ m to 50 ⁇ m.
  • the plate-like silicon body preferably has a (longitudinal direction length) / (thickness) in the range of 2 to 1,000.
  • the layered structure of the plate-like silicon body is considered to be the remnant of the Si layer in CaSi 2 of the raw material.
  • the oxygen-containing silicon material of the present invention may contain either or both of amorphous silicon and silicon crystals.
  • the size of the silicon crystal is preferably nano-sized. Specifically, the size of the silicon crystal is preferably in the range of 0.5 nm to 300 nm, more preferably in the range of 1 nm to 100 nm, still more preferably in the range of 1 nm to 50 nm, particularly preferably in the range of 1 nm to 10 nm preferable.
  • the size of the silicon crystal is calculated from the Scheller equation using the half value width of the diffraction peak of the Si (111) surface of the obtained XRD chart by performing X-ray diffraction measurement (XRD measurement) on the silicon material. Ru.
  • the ratio of crystal to amorphous in silicon of the oxygen-containing silicon material of the present invention is 0: 100 to 100: 0, 1: 99 to 50: 50, 0: 100 to 30: 70, 5: 95 to 30:
  • the range of 70, 10: 90 to 20: 80 can be exemplified.
  • the oxygen-containing silicon material of the present invention is preferably in the form of powder, and is preferably an aggregate of particles exhibiting a certain particle size distribution.
  • the average particle diameter of the oxygen-containing silicon material of the present invention is preferably in the range of 0.5 to 30 ⁇ m, more preferably in the range of 1 to 20 ⁇ m, and still more preferably in the range of 2 to 10 ⁇ m.
  • the average particle size means the D 50 as measured by conventional laser diffraction type particle size distribution measuring apparatus.
  • the BET specific surface area of the oxygen-containing silicon material of the present invention is in the range of 0.5 to 15 m 2 / g, in the range of 0.5 to 10 m 2 / g, in the range of 1 to 10 m 2 / g, 3 to The range of 10 m 2 / g can be exemplified.
  • the production method of the present invention a method for producing a negative electrode active material containing the oxygen-containing silicon material of the present invention (hereinafter, sometimes simply referred to as “the production method of the present invention”) will be described.
  • the key to the production method of the present invention is to set the temperature of the reaction solution to 15 to 50 ° C. in the step of reacting CaSi 2 with an aqueous acid solution to synthesize an oxygen-containing layered silicon compound containing layered polysilane. And controlling the oxygen content in the oxygen-containing layered silicon compound containing layered polysilane and the oxygen-containing silicon material of the present invention.
  • One aspect of the production method of the present invention is a-1) A step of synthesizing an oxygen-containing layered silicon compound containing layered polysilane by reacting CaSi 2 with an aqueous acid solution of 15 to 50 ° C. (hereinafter simply referred to as “a-1) step”. ), b) A step of synthesizing the oxygen-containing silicon material by heating the oxygen-containing layered silicon compound at 300 ° C. or higher (hereinafter simply referred to as “step b”). And the like.
  • step a-1 When an aqueous hydrogen chloride solution (hydrochloric acid) is used as the aqueous acid solution in step a-1), the reaction represented by the following formula (1) proceeds, and then, for example, on the surface of Si 6 H 6 which is a layered polysilane: It is considered that the reaction represented by the formula (2) proceeds. Therefore, the step a-1) can be said to be a key step for determining the oxygen content in the oxygen-containing layered silicon compound containing the layered polysilane and the oxygen-containing silicon material of the present invention.
  • Formula (1) 3CaSi 2 +6 HCl ⁇ Si 6 H 6 +3 CaCl 2
  • the temperature in the step a-1) is preferably in the range of 18 to 45 ° C., and more preferably in the range of 20 to 40 ° C. a-1)
  • a thermostat such as a thermostat may be used.
  • the treatment time of step a-1) may be 1 to 50 hours, 5 to 40 hours, or 10 to 30 hours.
  • step a-1 the following steps a-2-1) and a-2-2) may be employed.
  • steps a-2-1) A step of reacting CaSi 2 with an aqueous acid solution at -20 to 10 ° C a-2-2) Subsequent to the step a-2-1), the temperature of the reaction liquid is changed to 15 to 50 ° C to form a layer Process for synthesizing an oxygen-containing layered silicon compound containing polysilane
  • step a-2-2) is a key step for determining the oxygen content in the oxygen-containing layered silicon compound containing the layered polysilane and the oxygen-containing silicon material of the present invention.
  • Examples of the timing at which the step a-2-1) is switched to the step a-2-2) include a point at which the heat generation resulting from the reaction has taken a break, and a point at which bubbling from the reaction solution has taken a break.
  • the temperature-controlled device used in the a-2-1) step may be heated, or it may be used in the a-2-1) step
  • the same thermostat may be replaced with another thermostat which has been previously adjusted to a temperature range of 15 to 50.degree.
  • the temperature in the step a-2-1) is preferably in the range of -10 to 5 ° C, more preferably in the range of -5 to 5 ° C.
  • a specific time of the step a-2-1 for example, 10 minutes, 20 minutes, 1 hour or 2 hours, etc. can be exemplified after the completion of mixing of CaSi 2 and the aqueous acid solution.
  • the temperature in the step a-2-2) is preferably in the range of 18 to 45 ° C., and more preferably in the range of 20 to 40 ° C.
  • 1 to 50 hours, 5 to 40 hours, and 10 to 30 hours can be exemplified.
  • a process of reacting CaSi 2 with an aqueous acid solution to synthesize an oxygen-containing layered silicon compound containing layered polysilane may be collectively referred to as a process a).
  • CaSi 2 which is a raw material generally has a structure in which a Ca layer and a Si layer are laminated.
  • CaSi 2 may be synthesized by a known production method, or a commercially available one may be adopted.
  • CaSi 2 preferably contains Al.
  • the content of Al is preferably less than 4.5%, more preferably in the range of 0.01 to 3%, still more preferably in the range of 0.05 to 2%, and in the range of 0.1 to 1% Is particularly preferred.
  • hydrofluoric acid hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfuric acid, nitric acid, phosphoric acid, formic acid, acetic acid, methanesulfonic acid, tetrafluoroboric acid, hexafluorophosphoric acid, hexafluoro acid Arsenic acid, fluoroantimonic acid, hexafluorosilicic acid, hexafluorogermanic acid, hexafluorotin (IV) acid, trifluoroacetic acid, hexafluorotitanic acid, hexafluorozirconic acid, trifluoromethanesulfonic acid, fluorosulfonic acid are exemplified. Ru. These acids may be used alone or in combination.
  • the acid is preferably used in an amount capable of supplying 2 mol or more of protons to 1 mol of CaSi 2 .
  • the reason for using water as a solvent in step a) is that, from the technical point of view, removal of unnecessary substances such as CaCl 2 is easy and oxygen is extremely introduced into the layered polysilane produced in step a). It is an easy point.
  • the concentration of the acid in the aqueous acid solution is preferably 5 to 36% by mass, more preferably 5 to 30% by mass, still more preferably 10 to 30% by mass, particularly preferably 13 to 25% by mass, and 15 to 20% by mass Is most preferred. If the concentration of the acid is too low, the progress of the reaction will be slow and the production efficiency will be reduced. On the other hand, when the concentration of the acid is too high, an element derived from the acid anion is contained in a large amount in the oxygen-containing silicon material of the present invention.
  • the reaction conditions in the step a) are preferably under an inert gas atmosphere such as nitrogen, helium or argon, and are preferably under stirring conditions.
  • a filtration step, a washing step, and a drying step may be appropriately carried out.
  • an inert gas atmosphere such as nitrogen, helium or argon.
  • the step b) is a step of heating the oxygen-containing layered silicon compound at 300 ° C. or higher.
  • the step b) is a step of synthesizing an oxygen-containing silicon material by releasing hydrogen or the like from the oxygen-containing layered silicon compound by heating.
  • the reaction formula when hydrogen is released from the layered polysilane in step b) is as follows. Si 6 H 6 ⁇ 6 Si + 3 H 2 ⁇
  • the step b) is preferably carried out under a non-oxidizing atmosphere having a lower oxygen content than under normal atmosphere.
  • a non-oxidizing atmosphere a reduced pressure atmosphere including vacuum, an inert gas atmosphere such as nitrogen, helium, argon and the like can be exemplified.
  • the heating temperature is preferably in the range of 300 ° C. to 1000 ° C., more preferably in the range of 500 ° C. to 900 ° C., and still more preferably in the range of 600 ° C. to 800 ° C. If the heating temperature is too low, desorption of hydrogen may not be sufficient.
  • the heating temperature is too high, crystallization of silicon in the oxygen-containing silicon material may proceed excessively, which may lead to a decrease in performance as a negative electrode active material.
  • the heating time may be appropriately set in accordance with the heating temperature, and it is also preferable to determine the heating time while measuring the amount of hydrogen and the like which leaks out of the reaction system.
  • the ratio of amorphous silicon and silicon crystals contained in the oxygen-containing silicon material to be produced, and the size of silicon crystals can also be prepared, and further, it is produced It is also possible to adjust the shape and size of a nano-level thick layer including amorphous silicon and silicon crystals contained in the oxygen-containing silicon material.
  • the oxygen-containing silicon material of the present invention may be pulverized or classified into particles having a constant particle size distribution.
  • the oxygen-containing silicon material of the present invention can be used as a negative electrode active material of a secondary battery such as a lithium ion secondary battery.
  • a secondary battery such as a lithium ion secondary battery.
  • a method of carbon coating a mechanical milling method in which a mixture of oxygen-containing silicon material and carbon powder is subjected to strong pressure and then stirred and integrated, or carbon generated from a carbon source is vapor-deposited onto the oxygen-containing silicon material Can be exemplified by chemical vapor deposition (CVD).
  • the CVD method is preferable as a carbon coating method in that the surface of the oxygen-containing silicon material can be uniformly coated with a thin carbon layer. Then, among the CVD methods, a thermal CVD method in which a gaseous organic substance which is a carbon source is decomposed by heat to generate carbon is preferable.
  • the carbon mass% (W C %) in the carbon-coated oxygen-containing silicon material of the present invention preferably satisfies 1 ⁇ W C ⁇ 10, more preferably 3 ⁇ W C ⁇ 9, and 5 It is further preferable to satisfy ⁇ W c ⁇ 8.
  • the numerical range described for the oxygen-containing silicon material of the present invention is incorporated.
  • a secondary battery including the oxygen-containing silicon material of the present invention as a negative electrode active material will be described by taking a lithium ion secondary battery as an example.
  • a lithium ion secondary battery including the oxygen-containing silicon material of the present invention as a negative electrode active material is referred to as a lithium ion secondary battery of the present invention.
  • the lithium ion secondary battery of the present invention includes a positive electrode, a negative electrode including the oxygen-containing silicon material of the present invention as a negative electrode active material, an electrolytic solution, and a separator as necessary.
  • the positive electrode has a current collector and a positive electrode active material layer bonded to the surface of the current collector.
  • the current collector refers to a chemically inert electron conductor for keeping current flowing to the electrode during discharge or charge of the lithium ion secondary battery.
  • As the current collector at least one selected from silver, copper, gold, aluminum, tungsten, cobalt, zinc, nickel, iron, platinum, tin, indium, titanium, ruthenium, tantalum, chromium, molybdenum, stainless steel, etc. A metal material can be illustrated.
  • the current collector may be coated with a known protective layer. What processed the surface of a collector by a well-known method may be used as a collector.
  • the current collector can take the form of a foil, a sheet, a film, a line, a rod, a mesh or the like. Therefore, as the current collector, for example, metal foils such as copper foil, nickel foil, aluminum foil, and stainless steel foil can be suitably used.
  • the thickness is preferably in the range of 1 ⁇ m to 100 ⁇ m.
  • the positive electrode active material layer contains a positive electrode active material and, if necessary, a conductive aid and / or a binder.
  • a positive electrode active material spinel such as LiMn 2 O 4 and a solid solution composed of a mixture of spinel and layered compound, LiMPO 4 , LiMVO 4 or Li 2 MSiO 4 (M in the formula is Co, Ni, Mn, Polyanionic compounds represented by (at least one of Fe) and the like can be mentioned.
  • tavorite compound (the M a transition metal) LiMPO 4 F, such as LiFePO 4 F represented by, Limbo 3 such LiFeBO 3 (M is a transition metal) include borate-based compound represented by be able to.
  • any metal oxide used as a positive electrode active material may have the above composition formula as a basic composition, and one obtained by replacing the metal element contained in the basic composition with another metal element can also be used.
  • a positive electrode active material a positive electrode active material containing no lithium ion contributing to charge and discharge, for example, a simple substance of sulfur, a compound of sulfur and carbon, a metal sulfide such as TiS 2 , V 2 O 5 , MnO Oxides such as 2 , polyaniline and anthraquinone, and compounds containing these aromatics in the chemical structure, conjugated materials such as conjugated diacetic acid organic substances, and other known materials can also be used.
  • a compound having a stable radical such as nitroxide, nitronyl nitroxide, galvinoxyl, phenoxyl or the like may be adopted as the positive electrode active material.
  • a positive electrode active material containing no lithium it is necessary to add ions to the positive electrode and / or the negative electrode by a known method.
  • a metal or a compound containing the ions may be used.
  • a conductive aid is added to enhance the conductivity of the electrode. Therefore, the conductive additive may be optionally added when the conductivity of the electrode is insufficient, and may not be added when the conductivity of the electrode is sufficiently excellent.
  • the conductive support agent may be any chemically active high electron conductor, and carbon black fine particles such as carbon black, graphite, vapor grown carbon fiber, and various metal particles are exemplified. Ru. Examples of the carbon black include acetylene black, ketjen black (registered trademark), furnace black, channel black and the like. These conductive assistants can be added to the active material layer singly or in combination of two or more.
  • the ratio is more preferably 0.2, and more preferably 1: 0.02 to 1: 0.15. If the amount of the conductive additive is too small, efficient conductive paths can not be formed. If the amount of the conductive additive is too large, the formability of the active material layer deteriorates and the energy density of the electrode decreases.
  • the binder plays the role of anchoring the active material and the conductive aid to the surface of the current collector and maintaining the conductive network in the electrode.
  • the binder may, for example, be a fluorine-containing resin such as polyvinylidene fluoride, polytetrafluoroethylene or fluororubber, a thermoplastic resin such as polypropylene or polyethylene, an imide resin such as polyimide or polyamideimide, an alkoxysilyl group-containing resin, Examples include acrylic resins such as meta) acrylic acid, styrene-butadiene rubber (SBR), and carboxymethyl cellulose. These binders may be used alone or in combination.
  • the ratio is more preferably 0.2, and more preferably 1: 0.02 to 1: 0.15.
  • the negative electrode includes a current collector and a negative electrode active material layer bonded to the surface of the current collector.
  • As the current collector one described for the positive electrode may be appropriately adopted appropriately.
  • the negative electrode active material layer contains a negative electrode active material and, if necessary, a conductive aid and / or a binder.
  • any material containing the oxygen-containing silicon material of the present invention may be used, and only the oxygen-containing silicon material of the present invention may be adopted, and the oxygen-containing silicon material of the present invention and the known negative electrode active material You may use together.
  • those described for the positive electrode may be appropriately adopted at the same mixing ratio.
  • a crosslinked polymer in which a carboxyl group-containing polymer such as polyacrylic acid or polymethacrylic acid as disclosed in WO 2016/063882 is crosslinked with a polyamine such as diamine may be used as a binder.
  • diamine used for the cross-linked polymer examples include alkylene diamines such as ethylene diamine, propylene diamine and hexamethylene diamine, 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, isophorone diamine, bis (4-aminocyclohexyl) methane and the like.
  • Saturated carbocyclic ring diamine m-phenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylether, bis (4-aminophenyl) sulfone, benzidine, o-tolidine, 2,4- Aromatic diamines such as tolylene diamine, 2,6-tolylene diamine, xylylene diamine and naphthalene diamine can be mentioned.
  • an active material layer on the surface of a current collector current collection can be performed using conventionally known methods such as roll coating, die coating, dip coating, doctor blade method, spray coating, and curtain coating.
  • the active material may be applied to the surface of the body.
  • the active material, the solvent, and, if necessary, the binder and / or the conductive auxiliary agent are mixed to prepare a slurry.
  • the solvent include N-methyl-2-pyrrolidone, methanol, methyl isobutyl ketone and water.
  • the slurry is applied to the surface of a current collector and then dried. The dried one may be compressed to increase the electrode density.
  • the electrolytic solution contains a non-aqueous solvent and an electrolyte dissolved in the non-aqueous solvent.
  • cyclic carbonate As the non-aqueous solvent, cyclic carbonate, cyclic ester, chain carbonate, chain ester, ethers and the like can be used.
  • cyclic carbonates include ethylene carbonate, propylene carbonate, butylene carbonate, and vinylene carbonate.
  • cyclic esters include gamma butyrolactone, 2-methyl-gamma butyrolactone, acetyl-gamma butyrolactone, and gamma valerolactone.
  • chain carbonates include dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dipropyl carbonate, and ethyl methyl carbonate.
  • chain esters examples include propionic acid alkyl ester, malonic acid dialkyl ester, acetic acid alkyl ester and the like.
  • ethers tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane, 1,2-dibutoxyethane can be exemplified.
  • non-aqueous solvent a compound in which part or all of hydrogens in the chemical structure of the above specific solvent is substituted with fluorine may be adopted.
  • Examples of the electrolyte include lithium salts such as LiClO 4 , LiAsF 6 , LiPF 6 , LiBF 4 , LiCF 3 SO 3 , LiN (CF 3 SO 2 ) 2 and LiN (FSO 2 ) 2 .
  • lithium salts such as LiClO 4 , LiAsF 6 , LiPF 6 , LiBF 4 , LiCF 3 SO 3 , LiN (CF 3 SO 2 ) 2 and LiN (FSO 2 ) 2 .
  • lithium salts such as LiClO 4 , LiPF 6 , LiBF 4 , LiN (FSO 2 ) 2 and the like in nonaqueous solvents such as ethylene carbonate, dimethyl carbonate, propylene carbonate, diethyl carbonate and the like
  • nonaqueous solvents such as ethylene carbonate, dimethyl carbonate, propylene carbonate, diethyl carbonate and the like
  • a solution dissolved at a concentration of 1 / L, 1 to 3 mol / L, or 1.6 to 2.5 mol / L can be exemplified.
  • the separator separates the positive electrode and the negative electrode, and allows lithium ions to pass while preventing a short circuit due to the contact of the both electrodes.
  • synthetic resins such as polytetrafluoroethylene, polypropylene, polyethylene, polyimide, polyamide, polyaramid (Aromatic polyamide), polyester, polyacrylonitrile, etc., polysaccharides such as cellulose and amylose, natural substances such as fibroin, keratin, lignin and suberin Examples thereof include porous bodies, non-woven fabrics, and woven fabrics using one or more kinds of electrically insulating materials such as polymers and ceramics.
  • the separator may have a multilayer structure.
  • the positive electrode and the negative electrode sandwich a separator to form an electrode body.
  • the electrode body may be any of a laminated type in which a positive electrode, a separator and a negative electrode are stacked, or a wound type in which a laminate of a positive electrode, a separator and a negative electrode is wound.
  • the shape of the lithium ion secondary battery of the present invention is not particularly limited, and various shapes such as cylindrical, square, coin, and laminate types can be adopted.
  • the lithium ion secondary battery of the present invention may be mounted on a vehicle.
  • the vehicle may be a vehicle using electric energy from a lithium ion secondary battery for all or part of its power source, and may be, for example, an electric vehicle, a hybrid vehicle, or the like.
  • a lithium ion secondary battery is mounted on a vehicle, a plurality of lithium ion secondary batteries may be connected in series to form a battery pack.
  • various household appliances driven by a battery such as a personal computer and a mobile communication apparatus, as well as a vehicle, an office apparatus, an industrial apparatus and the like can be mentioned.
  • the lithium ion secondary battery of the present invention can be used in wind power generation, solar power generation, hydroelectric power generation, storage devices and power smoothing devices for electric power systems, power sources for power and / or accessories of ships, etc., aircraft, Power supply source for power of spacecraft and / or accessories, auxiliary power supply for vehicles not using electricity as power source, power supply for mobile home robots, power supply for system backup, power supply for uninterruptible power supply, You may use for the electrical storage apparatus which stores temporarily the electric power required for charge in the charge station etc. for electric vehicles.
  • the reaction vessel containing 35 mass% hydrochloric acid was placed in a thermostat at 18 ° C. After confirming that the temperature of hydrochloric acid had reached 18 ° C., the above CaSi 2 powder was gradually introduced into the hydrochloric acid under a nitrogen gas atmosphere and under stirring conditions. Stirring was continued for 2 hours after the addition of the CaSi 2 powder, and then the reaction solution was filtered. The residue was washed with distilled water and then with methanol and dried under reduced pressure to obtain the oxygen-containing layered silicon compound of Example 1.
  • the negative electrode and the lithium ion secondary battery of Example 1 were produced as follows.
  • a polyacrylic acid having a weight average molecular weight of 800,000 was dissolved in N-methyl-2-pyrrolidone to prepare a polyacrylic acid solution containing 10% by mass of polyacrylic acid.
  • a solution of 4,4'-diaminodiphenylmethane was prepared by dissolving 0.2 g (1.0 mmol) of 4,4'-diaminodiphenylmethane in 0.4 mL of N-methyl-2-pyrrolidone.
  • Example 1 72.5 parts by mass of the oxygen-containing silicon material of Example 1 as a negative electrode active material, 13.5 parts by mass of acetylene black as a conduction aid, and 14 parts by mass of solid content as a binder And, an appropriate amount of N-methyl-2-pyrrolidone was mixed to prepare a slurry.
  • a copper foil was prepared as a current collector for the negative electrode.
  • the slurry was applied in the form of a film on the surface of the copper foil using a doctor blade.
  • the copper foil coated with the slurry was dried to remove N-methyl-2-pyrrolidone. Thereafter, the resultant was pressed and baked at 180 ° C. to produce the negative electrode of Example 1 in which the negative electrode active material layer was formed.
  • a solution in which LiPF 6 was dissolved at a concentration of 1 mol / L was used as an electrolytic solution in a mixed solvent in which ethylene carbonate and diethyl carbonate were mixed at a volume ratio of 1: 1.
  • the negative electrode was cut to a diameter of 11 mm and used as an evaluation electrode.
  • a metal lithium foil having a thickness of 500 ⁇ m was cut to a diameter of 13 mm and used as a counter electrode.
  • a glass filter (Hoechst Celanese) and celgard 2400 (Polypore Co., Ltd.) which is a single-layer polypropylene were prepared as a separator.
  • the two types of separators were sandwiched between the counter electrode and the evaluation electrode in the order of the counter electrode, the glass filter, celgard 2400, and the evaluation electrode to form an electrode body.
  • the electrode body was housed in a coin-type battery case CR2032 (Hohsen Co., Ltd.).
  • the electrolytic solution was injected into the battery case, and the battery case was sealed to manufacture the lithium ion secondary battery of Example 1.
  • Example 2 The oxygen-containing layered silicon compound, the oxygen-containing silicon material, the negative electrode, and the lithium ion secondary battery of Example 2 are the same as in Example 1 except that in the step a), the temperature of the constant temperature bath is 40 ° C. Manufactured.
  • Comparative example 1 The oxygen-containing layered silicon compound, the oxygen-containing silicon material, the negative electrode, and the lithium ion secondary battery of Comparative Example 1 are prepared in the same manner as in Example 1 except that the temperature of the constant temperature bath is set to 0 ° C. in step a). Manufactured.
  • Comparative example 2 The oxygen-containing layered silicon compound, the oxygen-containing silicon material, the negative electrode, and the lithium ion secondary battery of Comparative Example 2 are the same as in Example 1 except that in the step a), the temperature of the constant temperature bath is 60 ° C. Manufactured.
  • the initial efficiency and capacity retention rate were calculated by the following formulas.
  • Initial efficiency (%) 100 ⁇ (initial discharge capacity) / (initial charge capacity)
  • Capacity retention rate (%) 100 ⁇ (discharge capacity at 50 cycles) / (discharge capacity at 1 cycle)
  • the results of the initial efficiency and capacity retention are shown in Table 2 along with some of the elemental analysis results. Further, FIG. 1 shows the relationship between the integrated capacity and the discharge capacity of each lithium ion secondary battery in 50 charge and discharge cycles.
  • Example 1 shows the relationship between the cumulative capacity and the discharge capacity of each lithium ion secondary battery that the oxygen-containing silicon materials of Example 1 and Example 2 are particularly excellent negative electrode active materials. .
  • the BET specific surface area of the oxygen-containing silicon material tends to increase as the temperature in the step a) rises, but it can be said that it becomes substantially constant at 40 ° C. or higher.
  • the proportions of silicon crystals and amorphous silicon in the oxygen-containing silicon material are considered to have no correlation with the temperature in the step a).
  • Example 3 An Al-containing CaSi 2 powder was prepared as follows. Ca, Al and Si were weighed in a carbon crucible. The elemental composition ratio of Ca and Si was 1: 2, and the amount of Al added was 1% with respect to the total mass of Ca, Al and Si. A carbon crucible was heated at around 1300 ° C. in a high frequency induction heating apparatus under an argon gas atmosphere to obtain a molten metal containing Ca, Al and Si. The molten metal is poured into a predetermined mold to cool and solidify. The solid was crushed into CaSi 2 powder and then subjected to a) step.
  • Process a-2-1) Process A reaction vessel containing 18 mass% hydrochloric acid was placed in a thermostat at 0 ° C. After confirming that the temperature of the hydrochloric acid reached 0 ° C., the CaSi 2 powder was gradually introduced into the hydrochloric acid under a nitrogen gas atmosphere and under stirring conditions. Stirring was continued for 15 minutes after the addition of the CaSi 2 powder.
  • Example 3 Thereafter, in the same manner as in Example 1, a negative electrode and a lithium ion secondary battery of Example 3 were produced.
  • Example 4 The oxygen-containing layered silicon compound of Example 4, oxygen-containing in the same manner as in Example 3 except that in the step a-2-2) the temperature of the thermostatic chamber was raised to 30 ° C. at a rate of 1 ° C./min. A silicon material, a negative electrode and a lithium ion secondary battery were manufactured.
  • Example 5 The oxygen-containing layered silicon compound of Example 5, oxygen-containing in the same manner as in Example 3 except that in the step a-2-2) the temperature of the thermostatic chamber was raised to 40 ° C. at a rate of 1 ° C./min. A silicon material, a negative electrode and a lithium ion secondary battery were manufactured.
  • Example 6 The oxygen-containing layered silicon compound, the oxygen-containing silicon material, the negative electrode, and the lithium ion secondary battery of Example 6 were manufactured in the same manner as in Example 3 except that the process a) was performed as follows.
  • Initial efficiency (%) 100 ⁇ (initial discharge capacity) / (initial charge capacity)
  • Capacity retention rate (%) 100 ⁇ (discharge capacity at 50 cycles) / (discharge capacity at 1 cycle)
  • the results of the initial charge capacity, the initial discharge capacity, the initial efficiency, and the capacity retention rate are shown in Tables 5 and 6 together with part of the results of the elemental analysis.
  • Example 6 shows equivalent results in terms of battery characteristics. From the viewpoint of safety in terms of work, it is reasonable to adopt a production method in which the reaction is allowed to proceed under low temperature conditions and the temperature is gradually raised when CaSi 2 powder in which a relatively vigorous reaction occurs is caused .
  • Example 7 An Al-containing CaSi 2 powder was prepared as follows. Ca, Al and Si were weighed in a carbon crucible. The elemental composition ratio of Ca and Si was 1: 2, and the amount of Al added was 1% with respect to the total mass of Ca, Al and Si. A carbon crucible was heated at around 1300 ° C. in a high frequency induction heating apparatus under an argon gas atmosphere to obtain a molten metal containing Ca, Al and Si. The molten metal is poured into a predetermined mold to cool and solidify. The solid was crushed into CaSi 2 powder and then subjected to a) step.
  • Process a-2-1) A reaction vessel containing 18 mass% hydrochloric acid was placed in a thermostat at 0 ° C. After confirming that the temperature of the hydrochloric acid reached 0 ° C., the CaSi 2 powder was gradually introduced into the hydrochloric acid under a nitrogen gas atmosphere and under stirring conditions. Stirring was continued for 15 minutes after the addition of the CaSi 2 powder.
  • Step a-2-1 the temperature of the thermostat was raised to 20 ° C. at a rate of 1 ° C./min, and the reaction solution was stirred overnight. Thereafter, the reaction solution was filtered. The residue was washed with distilled water and then with methanol and dried under reduced pressure to obtain the oxygen-containing layered silicon compound of Example 7.
  • Example 7 Carbon Coating Step The oxygen-containing silicon material of Example 7 was placed in a rotary kiln type reactor, and thermal CVD was performed at 880 ° C. for 60 minutes under aeration of propane-argon mixed gas, and carbon coated. An oxygen-containing silicon material was obtained. This was used as the carbon-coated oxygen-containing silicon material of Example 7.
  • the negative electrode and lithium ion secondary battery of Example 7 were produced as follows.
  • a polyacrylic acid having a weight average molecular weight of 800,000 was dissolved in N-methyl-2-pyrrolidone to prepare a polyacrylic acid solution containing 10% by mass of polyacrylic acid.
  • a solution of 4,4'-diaminodiphenylmethane was prepared by dissolving 0.2 g (1.0 mmol) of 4,4'-diaminodiphenylmethane in 0.4 mL of N-methyl-2-pyrrolidone.
  • Example 7 78.5 parts by mass of the carbon-coated silicon material of Example 7 as a negative electrode active material, 10.5 parts by mass of acetylene black as a conductive additive, and the above-mentioned binding in an amount such that the solid content is 11 parts by mass as a binder
  • the slurry was prepared by mixing the agent solution and an appropriate amount of N-methyl-2-pyrrolidone.
  • a copper foil was prepared as a current collector for the negative electrode.
  • the slurry was applied in the form of a film on the surface of the copper foil using a doctor blade.
  • the copper foil coated with the slurry was dried to remove N-methyl-2-pyrrolidone. Thereafter, pressing and baking at 180 ° C. were performed to manufacture the negative electrode of Example 7 in which the negative electrode active material layer was formed.
  • the -2-pyrrolidone was mixed to produce a slurry.
  • An aluminum foil was prepared as a positive electrode current collector.
  • the slurry was applied in the form of a film on the surface of the aluminum foil using a doctor blade.
  • the N-methyl-2-pyrrolidone was removed by drying the aluminum foil to which the slurry was applied. Thereafter, pressing and baking at 120 ° C. were performed to manufacture a positive electrode in which a positive electrode active material layer was formed on the surface of the positive electrode current collector.
  • Dimethyl carbonate, ethyl methyl carbonate and fluoroethylene carbonate were mixed at a volume ratio of 63:27:10 to give a mixed organic solvent.
  • LiPF 6 was dissolved in a mixed organic solvent at a concentration of 2 mol / L to form an electrolyte.
  • a porous membrane made of polyethylene was prepared as a separator.
  • the separator was sandwiched between the positive electrode and the negative electrode of Example 7 to form an electrode plate group.
  • the electrode plate group was covered with a pair of laminate films, the three sides were sealed, and then an electrolytic solution was injected into the bag-like laminate film. By sealing the remaining one side, the four sides were airtightly sealed to obtain a lithium ion secondary battery in which the electrode plate group and the electrolytic solution were sealed. This battery was used as a lithium ion secondary battery of Example 7.
  • Example 8 The oxygen-containing layered silicon compound of Example 8, oxygen-containing in the same manner as in Example 7 except that in the step a-2-2) the temperature of the thermostatic chamber was raised to 40 ° C. at a rate of 1 ° C./min. Silicon materials, carbon coated-oxygen containing silicon materials, negative electrodes and lithium ion secondary batteries were manufactured.
  • Comparative example 7 The negative electrode of Comparative Example 7 and lithium ion in the same manner as in Example 7 except that carbon-coated SiO (Shin-Etsu Chemical Co., Ltd.), which is a carbon-coated, oxygen-containing silicon material, was employed as the negative electrode active material. The following battery was manufactured.
  • carbon-coated SiO Shin-Etsu Chemical Co., Ltd.
  • Comparative Example 6 and Comparative Example 7 having a high oxygen content have low initial discharge capacity. It can be said that Example 7 and Example 8 in which the oxygen content and the silicon content are in appropriate ranges are all excellent in the initial discharge capacity, the 25 ° C. output and the 0 ° C. output. Further, from the results of Comparative Example 6 and Comparative Example 7 in which the oxygen content and the silicon content are equal, it is understood that the lithium ion secondary battery of Comparative Example 6 is more excellent in battery characteristics.
  • An oxygen-containing silicon material based on CaSi 2 has a unique structure in which a plurality of plate-like silicon bodies are stacked in the thickness direction, which is not observed in general SiO.
  • the reason why the lithium ion secondary battery of Comparative Example 6 is superior in output characteristics when Comparative Example 6 and Comparative Example 7 are compared is that a plurality of plate shapes possessed by the oxygen-containing silicon material of Comparative Example 6 It is considered that the silicon body is in the structure of being stacked in the thickness direction.
  • Example 9 An Al-containing CaSi 2 powder was prepared as follows. Ca, Al and Si were weighed in a carbon crucible. The elemental composition ratio of Ca and Si was 1: 2, and the amount of Al added was 1% with respect to the total mass of Ca, Al and Si. A carbon crucible was heated at around 1300 ° C. in a high frequency induction heating apparatus under an argon gas atmosphere to obtain a molten metal containing Ca, Al and Si. The molten metal is poured into a predetermined mold to cool and solidify. The solid was crushed into CaSi 2 powder and then subjected to a) step.
  • Process a-2-1) A reaction vessel containing 18 mass% hydrochloric acid was placed in a thermostat at 0 ° C. After confirming that the temperature of the hydrochloric acid reached 0 ° C., the CaSi 2 powder was gradually introduced into the hydrochloric acid under a nitrogen gas atmosphere and under stirring conditions. Stirring was continued for 15 minutes after the addition of the CaSi 2 powder.
  • Step a-2-1 the temperature of the thermostat was raised to 20 ° C. at a rate of 1 ° C./min, and the reaction solution was stirred overnight. Thereafter, the reaction solution was filtered. The residue was washed with distilled water and then with methanol and dried under reduced pressure to obtain the oxygen-containing layered silicon compound of Example 9.
  • Example 9 Carbon Coating Step The oxygen-containing silicon material of Example 9 was placed in a rotary kiln type reactor, and thermal CVD was performed at 880 ° C. and a residence time of 60 minutes under aeration of a propane-argon mixed gas, and carbon coated. An oxygen-containing silicon material was obtained. This was used as the carbon-coated oxygen-containing silicon material of Example 9.
  • the negative electrode and lithium ion secondary battery of Example 9 were produced as follows.
  • a polyacrylic acid having a weight average molecular weight of 800,000 was dissolved in N-methyl-2-pyrrolidone to prepare a polyacrylic acid solution containing 10% by mass of polyacrylic acid.
  • a solution of 4,4'-diaminodiphenylmethane was prepared by dissolving 0.2 g (1.0 mmol) of 4,4'-diaminodiphenylmethane in 0.4 mL of N-methyl-2-pyrrolidone.
  • Example 9 78.5 parts by mass of the carbon-coated silicon material of Example 9 as a negative electrode active material, 10.5 parts by mass of acetylene black as a conductive additive, and the above-mentioned binding in an amount such that the solid content is 11 parts by mass as a binder
  • the slurry was prepared by mixing the agent solution and an appropriate amount of N-methyl-2-pyrrolidone.
  • a copper foil was prepared as a current collector for the negative electrode.
  • the slurry was applied in the form of a film on the surface of the copper foil using a doctor blade.
  • the copper foil coated with the slurry was dried to remove N-methyl-2-pyrrolidone. After that, pressing and baking at 180 ° C. manufactured a negative electrode of Example 9 in which a negative electrode active material layer was formed.
  • a solution in which LiPF 6 was dissolved at a concentration of 1 mol / L was used as an electrolytic solution in a mixed solvent in which ethylene carbonate and diethyl carbonate were mixed at a volume ratio of 1: 1.
  • the negative electrode was cut to a diameter of 11 mm and used as an evaluation electrode.
  • a metal lithium foil having a thickness of 500 ⁇ m was cut to a diameter of 13 mm and used as a counter electrode.
  • a glass filter (Hoechst Celanese) and celgard 2400 (Polypore Co., Ltd.) which is a single-layer polypropylene were prepared as a separator.
  • the two types of separators were sandwiched between the counter electrode and the evaluation electrode in the order of the counter electrode, the glass filter, celgard 2400, and the evaluation electrode to form an electrode body.
  • the electrode body was housed in a coin-type battery case CR2032 (Hohsen Co., Ltd.).
  • An electrolytic solution was injected into the battery case, the battery case was sealed, and a lithium ion secondary battery of Example 9 was manufactured.
  • Example 10 The oxygen-containing layered silicon compound of Example 10, oxygen-containing in the same manner as Example 9, except that in the step a-2-2) the temperature of the thermostatic chamber was raised to 40 ° C. at a rate of 1 ° C./min. Silicon materials, carbon coated-oxygen containing silicon materials, negative electrodes and lithium ion secondary batteries were manufactured.
  • the oxygen-containing layered silicon compound of Comparative Example 8 and the oxygen-containing silicon material of Comparative Example 8 are the same as in Example 9 except that the temperature of the constant temperature bath is not increased and maintained at 0 ° C. Carbon coated-oxygen containing silicon materials, negative electrodes and lithium ion secondary batteries were manufactured.
  • Comparative example 9 The oxygen-containing layered silicon compound of Comparative Example 9 in the same manner as in Example 9 except that in the step a-2-2) the temperature of the thermostatic chamber was raised to 60 ° C. at a rate of 1 ° C./min. Silicon materials, carbon coated-oxygen containing silicon materials, negative electrodes and lithium ion secondary batteries were manufactured.
  • the lithium ion secondary battery comprising the oxygen-containing silicon material of Example 9 and Example 10, in which oxygen mass% and silicon mass% are in appropriate ranges, has initial efficiency and capacity retention It can be said that the rate and integrated capacity are satisfied in a well-balanced manner.
  • An Al-containing CaSi 2 powder was prepared as follows. Ca, Al and Si were weighed in a carbon crucible. The elemental composition ratio of Ca and Si was 1: 2, and the amount of Al added was 1% with respect to the total mass of Ca, Al and Si. A carbon crucible was heated at around 1300 ° C. in a high frequency induction heating apparatus under an argon gas atmosphere to obtain a molten metal containing Ca, Al and Si. The molten metal is poured into a predetermined mold to cool and solidify. The solid was crushed into CaSi 2 powder and then subjected to a) step.
  • Process a-2-1) A reaction vessel containing 18 mass% hydrochloric acid was placed in a thermostat at 0 ° C. After confirming that the temperature of the hydrochloric acid reached 0 ° C., the CaSi 2 powder was gradually introduced into the hydrochloric acid under a nitrogen gas atmosphere and under stirring conditions. Stirring was continued for 15 minutes after the addition of the CaSi 2 powder.
  • Step a-2-1 the temperature of the thermostat was raised to 40 ° C. at a rate of 1 ° C./min, and the reaction solution was stirred overnight. Thereafter, the reaction solution was filtered. The residue was washed with distilled water and then with methanol and dried under reduced pressure to obtain the oxygen-containing layered silicon compound of Example 11.
  • Example 11 Carbon Coating Step The oxygen-containing silicon material of Example 11 was placed in a rotary kiln type reactor, and thermal CVD was performed under the conditions of 700 ° C. and a residence time of 60 minutes under aeration of a hexane-argon mixed gas, and carbon coated. An oxygen-containing silicon material was obtained. This was used as the carbon-coated oxygen-containing silicon material of Example 11.
  • the negative electrode and lithium ion secondary battery of Example 11 were produced as follows.
  • Example 11 72.5 parts by mass of the carbon-coated silicon material of Example 11 as a negative electrode active material, 13.5 parts by mass of acetylene black as a conductive additive, 14 parts by mass of polyamideimide as a binder, and an appropriate amount of N-methyl
  • the -2-pyrrolidone was mixed to produce a slurry.
  • a copper foil was prepared as a current collector for the negative electrode.
  • the slurry was applied in the form of a film on the surface of the copper foil using a doctor blade.
  • the copper foil coated with the slurry was dried to remove N-methyl-2-pyrrolidone. After that, pressing and baking at 180 ° C. manufactured a negative electrode of Example 11 in which a negative electrode active material layer was formed.
  • a solution in which LiPF 6 was dissolved at a concentration of 1 mol / L was used as an electrolytic solution in a mixed solvent in which ethylene carbonate and diethyl carbonate were mixed at a volume ratio of 1: 1.
  • the negative electrode was cut to a diameter of 11 mm and used as an evaluation electrode.
  • a metal lithium foil having a thickness of 500 ⁇ m was cut to a diameter of 13 mm and used as a counter electrode.
  • a glass filter (Hoechst Celanese) and celgard 2400 (Polypore Co., Ltd.) which is a single-layer polypropylene were prepared as a separator.
  • the two types of separators were sandwiched between the counter electrode and the evaluation electrode in the order of the counter electrode, the glass filter, celgard 2400, and the evaluation electrode to form an electrode body.
  • the electrode body was housed in a coin-type battery case CR2032 (Hohsen Co., Ltd.).
  • An electrolytic solution was injected into the battery case, and the battery case was sealed to manufacture a lithium ion secondary battery of Example 11.
  • Example 12 In the step of preparing the CaSi 2 powder containing Al, the procedure is the same as in Example 11 except that the addition amount of Al is set to 0.5% with respect to the total mass of Ca, Al and Si.
  • the oxygen-containing layered silicon compound of Example 12 the oxygen-containing silicon material, the carbon-coated oxygen-containing silicon material, the negative electrode and the lithium ion secondary battery were manufactured.
  • Example 13 At the step of preparing a CaSi 2 powder containing Al, without adding Al, except preparing the CaSi 2 powder not containing Al is in the same manner as in Example 11, the oxygen-containing layered silicon of Example 13 Compounds, oxygen-containing silicon materials, carbon coated-oxygen-containing silicon materials, negative electrodes and lithium ion secondary batteries were manufactured.
  • Example 14 (Example 14) b) In the same manner as in Example 11 except that the heating temperature in the step is 900 ° C., and the conditions for the carbon coating step are 880 ° C. and a residence time of 60 minutes under aeration of a propane-argon mixed gas.
  • An oxygen-containing layered silicon compound, an oxygen-containing silicon material, a carbon-coated oxygen-containing silicon material, a negative electrode and a lithium ion secondary battery of Example 14 were manufactured.
  • Example 15 (Example 15) b) In the same manner as in Example 13, except that the heating temperature in the step is 900 ° C., and the conditions for the carbon coating step are 880 ° C. and a residence time of 60 minutes under aeration of propane-argon mixed gas.
  • An oxygen-containing layered silicon compound, an oxygen-containing silicon material, a carbon-coated oxygen-containing silicon material, a negative electrode and a lithium ion secondary battery of Example 15 were manufactured.
  • the preferred oxygen-mass% carbon-coated oxygen-containing silicon material exhibits excellent characteristics as a negative electrode active material. Further, it can be seen that the oxygen mass%, silicon mass% and Al mass% of the carbon-coated silicon-containing silicon material affect the capacity retention rate of the secondary battery.

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Abstract

L'invention concerne : un matériau actif d'électrode négative qui contient un matériau de silicium et permet de modifier le taux de maintenance de capacité d'un accumulateur à une valeur appropriée ; et un procédé de production du matériau actif d'électrode négative. Elle concerne un matériau actif d'électrode négative caractérisé en ce qu'il contient un matériau de silicium contenant de l'oxygène dont la teneur en oxygène (WO %) est comprise entre 16 et 27 % exclus en masse (c.-à-d. 16 < WO < 27) et dont la teneur en silicium (WSi %) est comprise entre 62 et 81 % exclus en masse (c.-à-d. 62 < WSi < 81).
PCT/JP2018/023079 2017-09-26 2018-06-18 Matériau actif d'électrode négative contenant un matériau de silicium contenant de l'oxygène, et son procédé de production WO2019064728A1 (fr)

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WO2007015419A1 (fr) * 2005-08-02 2007-02-08 Matsushita Electric Industrial Co., Ltd. Électrode négative pour une batterie secondaire au lithium et son procédé de fabrication
JP2011222151A (ja) * 2010-04-05 2011-11-04 Shin Etsu Chem Co Ltd 非水電解質二次電池用負極材及び非水電解質二次電池用負極材の製造方法並びにリチウムイオン二次電池
WO2014080608A1 (fr) * 2012-11-21 2014-05-30 株式会社豊田自動織機 Matériau en silicium nanocristallin, matériau actif d'électrode négative, procédé de production dudit matériau et dispositif accumulateur électrique
JP2015106563A (ja) * 2013-11-29 2015-06-08 深▲セン▼市貝特瑞新能源材料股▲ふん▼有限公司 ＳＩＯｘ系複合負極材料、製造方法及び電池
JP2016138029A (ja) * 2015-01-29 2016-08-04 株式会社豊田自動織機 層状シリコン化合物及びシリコン材料の製造方法並びにシリコン材料を具備する二次電池

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007015419A1 (fr) * 2005-08-02 2007-02-08 Matsushita Electric Industrial Co., Ltd. Électrode négative pour une batterie secondaire au lithium et son procédé de fabrication
JP2011222151A (ja) * 2010-04-05 2011-11-04 Shin Etsu Chem Co Ltd 非水電解質二次電池用負極材及び非水電解質二次電池用負極材の製造方法並びにリチウムイオン二次電池
WO2014080608A1 (fr) * 2012-11-21 2014-05-30 株式会社豊田自動織機 Matériau en silicium nanocristallin, matériau actif d'électrode négative, procédé de production dudit matériau et dispositif accumulateur électrique
JP2015106563A (ja) * 2013-11-29 2015-06-08 深▲セン▼市貝特瑞新能源材料股▲ふん▼有限公司 ＳＩＯｘ系複合負極材料、製造方法及び電池
JP2016138029A (ja) * 2015-01-29 2016-08-04 株式会社豊田自動織機 層状シリコン化合物及びシリコン材料の製造方法並びにシリコン材料を具備する二次電池

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