WO2022160332A1 - Matériau actif d'électrode négative, électrode négative le comprenant, dispositif électrochimique et dispositif électronique - Google Patents

Matériau actif d'électrode négative, électrode négative le comprenant, dispositif électrochimique et dispositif électronique Download PDF

Info

Publication number
WO2022160332A1
WO2022160332A1 PCT/CN2021/074629 CN2021074629W WO2022160332A1 WO 2022160332 A1 WO2022160332 A1 WO 2022160332A1 CN 2021074629 W CN2021074629 W CN 2021074629W WO 2022160332 A1 WO2022160332 A1 WO 2022160332A1
Authority
WO
WIPO (PCT)
Prior art keywords
negative electrode
active material
graphite
electrode active
material layer
Prior art date
Application number
PCT/CN2021/074629
Other languages
English (en)
Chinese (zh)
Inventor
唐佳
何丽红
王硕
谢远森
Original Assignee
宁德新能源科技有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 宁德新能源科技有限公司 filed Critical 宁德新能源科技有限公司
Priority to PCT/CN2021/074629 priority Critical patent/WO2022160332A1/fr
Priority to CN202310887591.8A priority patent/CN116885176A/zh
Priority to CN202180003010.9A priority patent/CN113795947B/zh
Publication of WO2022160332A1 publication Critical patent/WO2022160332A1/fr

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
    • 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
    • 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
    • H01M4/133—Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
    • C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
    • 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 application relates to the field of energy storage, in particular to a negative electrode active material and a negative electrode, an electrochemical device and an electronic device comprising the same, especially a lithium ion battery.
  • the battery is not only required to be light, but also required to have a high capacity and a long operating life.
  • Lithium-ion batteries have taken a mainstream position in the market due to their outstanding advantages such as high energy density, high safety, no memory effect and long working life.
  • the present application provides an anode active material in an attempt to solve at least one problem in the related art to at least some extent.
  • the present application also provides a negative electrode, an electrochemical device, and an electronic device using the negative electrode active material.
  • the present application provides a negative electrode active material
  • the negative electrode active material includes graphite, wherein the graphite has a (002) crystal plane diffraction peak with a half width range of 0.260 measured by X-ray diffraction method. ° to 0.300°.
  • the range of the interplanar spacing d002 of the graphite is measured by X-ray diffraction to
  • the average stacking thickness Lc of the graphite particles along the c-axis direction is 27 nm to 32 nm, and the average size La of the graphite particles along the a-axis direction is 100 nm to 136 nm.
  • the graphite has a Dv50 of 7 ⁇ m to 14 ⁇ m, and the graphite has a Dv99 of 25 ⁇ m to 45 ⁇ m.
  • the graphite has a tap density greater than or equal to 0.7 g/cm 3 .
  • the present application provides a negative electrode comprising the negative electrode active material according to the present application.
  • the present application provides an electrochemical device comprising a negative electrode according to the present application.
  • the anode active material layer satisfies at least one of conditions (a) or (b) by Raman testing:
  • Id1 is the peak of the negative electrode active material layer at 1350cm ⁇ 1 strong; Ig is the peak intensity of the negative electrode active material layer at 1580 cm ⁇ 1 ; (Id1/Ig)max is the maximum value of the ratio of Id1 to Ig; (Id1/Ig)min is the minimum value of the ratio of Id1 to Ig ; and STDEV(Id1/Ig) is the variance of Id1/Ig.
  • the negative active material layer has a peak intensity of Id2 at 1620 cm ⁇ 1 and a peak intensity of Ig at 1580 cm ⁇ 1 , and the average value of the ratio of Id2 to Ig Id2 /Ig is 0.07 to 0.20.
  • the porosity of the anode active material layer is 20% to 35%.
  • the present application provides an electronic device comprising an electrochemical device according to the present application.
  • Electrochemical devices prepared according to the anode active material of the present application have higher capacity retention and energy density and improved kinetic performance.
  • FIG. 1 shows a picture of the X-ray diffraction (XRD) test of the negative electrode active material in Example 1 of the present application.
  • FIG. 2 shows the Raman test spectrum of the negative electrode active material in Example 2 of the present application.
  • FIG. 3 shows a distribution diagram of Id1/Ig of the negative electrode active material in Example 1 of the present application.
  • a list of items joined by the terms “one of”, “one of”, “one of” or other similar terms may mean any of the listed items. one.
  • the phrase “one of A and B” means A only or B only.
  • the phrase “one of A, B, and C” means A only; B only; or C only.
  • Item A may contain a single element or multiple elements.
  • Item B may contain a single element or multiple elements.
  • Item C may contain a single element or multiple elements.
  • a list of items connected by the terms “at least one of”, “at least one of”, “at least one of” or other similar terms may mean the listed items any combination of .
  • the phrase “at least one of A and B” means A only; B only; or A and B.
  • the phrase "at least one of A, B, and C” means A only; or B only; C only; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C.
  • Item A may contain a single element or multiple elements.
  • Item B may contain a single element or multiple elements.
  • Item C may contain a single element or multiple elements.
  • Dv50 is the particle size corresponding to the cumulative volume percentage of the negative electrode active material reaching 50%, and the unit is ⁇ m.
  • Dv99 is the particle size corresponding to the cumulative volume percentage of the negative active material reaching 99%, and the unit is ⁇ m.
  • Dv10 is the particle size corresponding to the cumulative volume percentage of the negative electrode active material reaching 10%, and the unit is ⁇ m.
  • the present application provides a negative electrode active material
  • the negative electrode active material includes graphite, wherein the graphite has a (002) crystal plane diffraction peak with a half width range of 0.260 measured by X-ray diffraction method. ° to 0.300°.
  • the half-peak width of the (002) crystal plane diffraction peak of the graphite is 0.260°, 0.280°, 0.300° or a range composed of any two of these values.
  • the range of the interplanar spacing d002 of the graphite is measured by X-ray diffraction to
  • the range of the interplanar spacing d002 of the graphite is measured by X-ray diffraction or a range of any two of these values.
  • the interplanar spacing of graphite is in this range, the capacity of the electrochemical device and the insertion and extraction speed of lithium ions during the charging and discharging process can be improved.
  • the average stacking thickness Lc of the graphite particles along the c-axis direction is 27 nm to 32 nm, and the average size La of the graphite particles along the a-axis direction is 100 nm to 136 nm.
  • Lc is 27 nm, 28 nm, 29 nm, 30 nm, 31 nm, 32 nm, or a range of any two of these values.
  • La is 100 nm, 105 nm, 110 nm, 115 nm, 120 nm, 125 nm, 130 nm, 136 nm, or a range of any two of these values.
  • the graphite has a gram capacity of 355 mAh/g to 365 mAh/g. In some embodiments, the graphite has a gram capacity of 355mAh/g, 358mAh/g, 360mAh/g, 362mAh/g, 365mAh/g, or a range of any two of these values.
  • the graphite has a Dv50 of 7 ⁇ m to 14 ⁇ m. In some embodiments, the graphite has a Dv50 of 7 ⁇ m, 9 ⁇ m, 11 ⁇ m, 13 ⁇ m, 14 ⁇ m, or a range of any two of these values.
  • the graphite has a Dv99 of 25 ⁇ m to 45 ⁇ m. In some embodiments, the graphite has a Dv99 of 25 ⁇ m, 28 ⁇ m, 30 ⁇ m, 32 ⁇ m, 35 ⁇ m, 38 ⁇ m, 40 ⁇ m, 42 ⁇ m, 43 ⁇ m, 45 ⁇ m, or a range of any two of these values.
  • the graphite has a tap density of greater than or equal to 7 g/cm 3 . In some embodiments, the graphite has a tap density of 0.7 g/cm 3 , 0.8 g/cm 3 , 0.9 g/cm 3 , 1.0 g/cm 3 , 1.1 g/cm 3 , 1.2 g/cm 3 or In the range of any two of these values, the amount of binder used for graphite within this range is small, and it is not easy to settle when preparing the negative electrode slurry, and the processability is good.
  • the present application provides a method for preparing any of the above-mentioned negative electrode active materials, the method comprising:
  • the graphite precursor includes at least one of petroleum coke, needle coke, sponge coke, or metal coke.
  • the particle size of the crushed graphite precursor is 7 ⁇ m to 14 ⁇ m.
  • the graphitization temperature is 2500°C, 2600°C, 2700°C, 2800°C, 2900°C, 3000°C, 3100°C, 3200°C, or a range of any two of these values.
  • the gram capacity of the graphite negative electrode active material is controlled by controlling the half-peak width of the (002) crystal plane diffraction peak of graphite and the graphite microcrystalline structures La and Lc within a certain range, thereby obtaining a graphite negative electrode active material with high gram capacity. ( ⁇ 355mAh/g).
  • the present application enables the graphite negative electrode active material to have higher capacity retention rate, energy density and improved kinetic performance.
  • the present application provides a negative electrode.
  • the negative electrode includes a current collector and a negative electrode active material layer on the current collector.
  • the negative electrode active material layer includes the negative electrode active material according to the present application.
  • the negative active material layer includes a binder.
  • binders include, but are not limited to: polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyfluoro Ethylene, ethylene oxide-containing polymers, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene Rubber, epoxy or nylon.
  • the anode active material layer includes a conductive material.
  • the conductive material includes, but is not limited to: natural graphite, artificial graphite, carbon black, acetylene black, ketjen black, carbon fiber, metal powder, metal fiber, copper, nickel, aluminum, silver, or polyphenylene derivative.
  • the current collector includes, but is not limited to, copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, or a conductive metal clad polymer substrate.
  • the negative electrode may be obtained by mixing an active material, a conductive material, and a binder in a solvent to prepare an active material composition, and coating the active material composition on a current collector.
  • the solvent may include, but is not limited to: deionized water, N-methylpyrrolidone.
  • the positive electrode is the positive electrode described in US Patent Application US9812739B, which is incorporated herein by reference in its entirety.
  • the positive electrode includes a current collector and a layer of positive active material on the current collector.
  • the positive active material includes, but is not limited to: lithium cobalt oxide (LiCoO 2 ), lithium nickel cobalt manganese (NCM) ternary material, lithium iron phosphate (LiFePO 4 ), or lithium manganate (LiMn 2 O 4 ).
  • the positive active material layer further includes a binder, and optionally a conductive material.
  • the binder improves the bonding of the positive electrode active material particles to each other, and also improves the bonding of the positive electrode active material to the current collector.
  • binders include, but are not limited to: polyvinyl alcohol, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene-containing Oxygenated polymers, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin or Nylon etc.
  • conductive materials include, but are not limited to, carbon-based materials, metal-based materials, conductive polymers, and mixtures thereof.
  • the carbon-based material is selected from natural graphite, artificial graphite, carbon black, acetylene black, ketjen black, carbon fiber, or any combination thereof.
  • the metal-based material is selected from metal powders, metal fibers, copper, nickel, aluminum, or silver.
  • the conductive polymer is a polyphenylene derivative.
  • the current collector may include, but is not limited to, aluminum.
  • the positive electrode can be prepared by a preparation method known in the art.
  • the positive electrode can be obtained by mixing an active material, a conductive material, and a binder in a solvent to prepare an active material composition, and coating the active material composition on a current collector.
  • the solvent may include, but is not limited to: N-methylpyrrolidone.
  • Electrolytes that can be used in the present application may be those known in the art.
  • the electrolyte includes an organic solvent, a lithium salt, and an additive.
  • the organic solvent of the electrolytic solution according to the present application may be any organic solvent known in the prior art that can be used as a solvent of the electrolytic solution.
  • the electrolyte used in the electrolyte solution according to the present application is not limited, and it may be any electrolyte known in the prior art.
  • the additive for the electrolyte according to the present application may be any additive known in the art as an additive for the electrolyte.
  • the organic solvent includes, but is not limited to: ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC), propylene carbonate or ethyl propionate.
  • the lithium salt includes at least one of an organic lithium salt or an inorganic lithium salt.
  • the lithium salts include, but are not limited to: lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate (LiBF 4 ), lithium difluorophosphate (LiPO 2 F 2 ), bistrifluoromethanesulfonimide Lithium LiN(CF 3 SO 2 ) 2 (LiTFSI), Lithium Bis(fluorosulfonyl)imide Li(N(SO 2 F) 2 )(LiFSI), Lithium Bisoxalate Borate LiB(C 2 O 4 ) 2 (LiBOB) ) or lithium difluorooxalate borate LiBF 2 (C 2 O 4 ) (LiDFOB).
  • LiPF 6 lithium hexafluorophosphate
  • LiBF 4 lithium tetrafluoroborate
  • LiPO 2 F 2 lithium difluorophosphate
  • LiPFSI bistrifluoromethanesulfonimide Lithium LiN(CF 3 SO
  • the concentration of the lithium salt in the electrolyte is: 0.5 mol/L to 3 mol/L, 0.5 mol/L to 2 mol/L, or 0.8 mol/L to 1.5 mol/L.
  • a separator is provided between the positive electrode and the negative electrode to prevent short circuits.
  • the material and shape of the separator that can be used in the present application are not particularly limited, and it may be any of the techniques disclosed in the prior art.
  • the separator includes a polymer or inorganic or the like formed from a material that is stable to the electrolyte of the present application.
  • the release film may include a substrate layer and a surface treatment layer.
  • the base material layer is a non-woven fabric, film or composite film with a porous structure, and the material of the base material layer is selected from at least one of polyethylene, polypropylene, polyethylene terephthalate or polyimide.
  • a polypropylene porous membrane, a polyethylene porous membrane, a polypropylene non-woven fabric, a polyethylene non-woven fabric or a polypropylene-polyethylene-polypropylene porous composite membrane can be selected.
  • At least one surface of the base material layer is provided with a surface treatment layer, and the surface treatment layer may be a polymer layer or an inorganic material layer, or a layer formed by mixing a polymer and an inorganic material.
  • the inorganic layer includes inorganic particles and a binder, and the inorganic particles are selected from aluminum oxide, silicon oxide, magnesium oxide, titanium oxide, hafnium oxide, tin oxide, ceria, nickel oxide, zinc oxide, calcium oxide, zirconium oxide, One or a combination of yttrium oxide, silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide and barium sulfate.
  • the binder is selected from polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, polyvinylpyrrolidone, polyvinyl ether, One or a combination of polymethyl methacrylate, polytetrafluoroethylene and polyhexafluoropropylene.
  • the polymer layer contains a polymer, and the material of the polymer is selected from polyamide, polyacrylonitrile, acrylate polymer, polyacrylic acid, polyacrylate, polyvinylpyrrolidone, polyvinyl ether, polyvinylidene fluoride or polyvinylidene fluoride. At least one of (vinylidene fluoride-hexafluoropropylene).
  • the present application provides an electrochemical device including any device that undergoes an electrochemical reaction.
  • the electrochemical device of the present application includes a positive electrode having a positive electrode active material capable of occluding and releasing metal ions; a negative electrode according to the present application; an electrolyte; and a separator interposed between the positive electrode and the negative electrode.
  • the anode active material layer satisfies at least one of the conditions (a) or (b): (a) 0.2 ⁇ (Id1/Ig)max-(Id1/ Ig)min ⁇ 0.7; (b)0.04 ⁇ STDEV(Id1/Ig) ⁇ 0.16; wherein Id1 is the peak intensity of the negative electrode active material layer at 1350cm -1 ; Ig is the negative electrode active material layer at 1580cm -1 (Id1/Ig)max is the maximum value of the ratio of Id1 to Ig; (Id1/Ig)min is the minimum value of the ratio of Id1 to Ig; and STDEV(Id1/Ig) is the variance of Id1/Ig.
  • the value of (Id1/Ig)max-(Id1/Ig)min is 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, or a range of any two of these values.
  • the value of STDEV(Id1/Ig) is 0.04, 0.06, 0.08, 0.10, 0.12, 0.14, 0.16, or a range of any two of these values.
  • the defect content of the negative electrode active material within the above range is within a suitable range, which is not only conducive to the entry of lithium ions into the graphite layer through the defects, but also because the thickness of the SEI film generated by the reaction between the defects of the negative electrode active material and the electrolyte is controlled within a certain range, It can ensure that the first effect is controlled within an appropriate range.
  • the porosity of the anode active material layer is 20% to 35%.
  • the negative electrode active material layer has a porosity of 20%, 25%, 28%, 30%, 32%, 35%, or a range of any two of these values.
  • the electrochemical devices of the present application include, but are not limited to, all kinds of primary or secondary batteries.
  • the electrochemical device is a lithium secondary battery.
  • the lithium secondary battery includes, but is not limited to, a lithium metal secondary battery, a lithium ion secondary battery, a lithium polymer secondary battery, or a lithium ion polymer secondary battery.
  • the electronic device of the present application may be any device using the electrochemical device according to the present application.
  • the electronic devices include, but are not limited to: notebook computers, pen input computers, mobile computers, e-book players, portable telephones, portable fax machines, portable copiers, portable printers, headsets , VCR, LCD TV, Portable Cleaner, Portable CD Player, Mini CD, Transceiver, Electronic Notepad, Calculator, Memory Card, Portable Recorder, Radio, Backup Power, Motor, Automobile, motorcycle, Power-assisted Bicycle, Bicycle , lighting equipment, toys, game consoles, clocks, power tools, flashes, cameras, large household batteries or lithium-ion capacitors, etc.
  • lithium ion batteries The preparation of lithium ion batteries is described below by taking lithium ion batteries as an example and in conjunction with specific embodiments. Those skilled in the art will understand that the preparation methods described in this application are only examples, and any other suitable preparation methods are included in the scope of this application. within the range.
  • the positive active material lithium cobaltate, acetylene black and polyvinylidene fluoride (abbreviated as PVDF) are fully stirred and mixed in an appropriate amount of N-methylpyrrolidone (abbreviated as NMP) solvent in a weight ratio of 96:2:2 to make it
  • NMP N-methylpyrrolidone
  • the negative electrode active material graphite, styrene-butadiene rubber (abbreviated as SBR) and sodium carboxymethyl cellulose (abbreviated as CMC) are fully stirred and mixed in deionized water solvent according to the weight ratio of 95:2:3 to form a uniform negative electrode Slurry; coat this slurry on the current collector copper foil, dry, cold-press the coated negative electrode, cut into pieces, and weld the tabs.
  • the coating weight of the single-sided negative electrode active material layer is 0.100 mg/ mm 2 , the coating thickness of the single-sided negative electrode active material layer was 65 ⁇ m, and the compaction density was 1.75 g/cm 3 .
  • the preparation method of graphite is as follows:
  • the graphite precursor (one or more of petroleum coke, needle coke, sponge coke and metal coke) is pulverized to a certain particle size by high-efficiency pulverizing equipment, and then the pulverized particles are sent to classification equipment , through the centrifugal separation effect of the equipment, the particle size of the particles is controlled to be Dv10 in the range of 3 ⁇ m to 5 ⁇ m, Dv50 in the range of 6 ⁇ m to 13 ⁇ m, and Dv99 in the range of 18 ⁇ m to 30 ⁇ m, and then the crushed particles are sent to the graphitization furnace for graphitization,
  • the graphitization equipment can be any one of an Acheson furnace, an inner-string graphitization furnace and a continuous graphitization furnace. Graphitization is carried out at °C to 3200 °C, and the required graphite is collected after graphitization. The graphite parameters were adjusted by controlling the precursor particle size and graphitization temperature.
  • LiPF 6 In a dry argon atmosphere, add LiPF 6 to the solvent mixed with ethylene carbonate (EC), propylene carbonate (PC), and diethyl carbonate (DEC) (weight ratio 1:1:1) and mix well , wherein the concentration of LiPF 6 is 1.15mol/L, then add fluoroethylene carbonate and 1,3-propane sultone, mix well to obtain an electrolyte, wherein based on the total weight of the electrolyte, the fluoroethylene carbonate The content is 5%, and the content of 1,3-propane sultone is 2%.
  • EC ethylene carbonate
  • PC propylene carbonate
  • DEC diethyl carbonate
  • a polyethylene porous polymer film with a thickness of 7 ⁇ m was used as the separator.
  • the positive electrode, the separator and the negative electrode are stacked in order, so that the separator is in the middle of the positive electrode and the negative electrode, then wound, placed in the outer packaging foil, and injected with the electrolyte prepared above, after vacuum packaging, standing, chemical formation, After shaping and other processes, a lithium ion battery is obtained.
  • Test method for (002, 004, 110) crystal plane diffraction peaks (hereinafter referred to as "002 peak, 004 peak, 110 peak"): X-ray powder diffractometer (XRD, instrument model: Bruker D8ADVANCE) was used to test the negative electrode active material graphite , the target material is Cu K ⁇ ; the voltage and current are 40KV/40mA, the scanning angle range is 5° to 80°, the scanning step is 0.00836°, and the time of each step is 0.3s.
  • XRD X-ray powder diffractometer
  • FIG. 1 shows a picture of the X-ray diffraction (XRD) test of the negative electrode active material in Example 1 of the present application; FWHM represents the minimum and maximum points of the peak intensity of the 002 peak. 50% of the full width between.
  • XRD X-ray diffraction
  • La the average size of graphite crystallites along the a-axis direction
  • La K ⁇ / ⁇ (2 ⁇ ) /cos ⁇ .
  • ⁇ the half width of the diffraction peak of the 100 crystal plane
  • ⁇ the wavelength (0.154056)
  • ⁇ is the position angle of the maximum peak intensity of the 100 crystal plane diffraction peak.
  • Lc the average stacking thickness of graphite crystallites along the c-axis direction
  • Lc K ⁇ / ⁇ (2 ⁇ ) /cos ⁇ .
  • ⁇ is the half width of the 002 peak
  • ⁇ is the wavelength (0.154056)
  • ⁇ is the position angle of the maximum peak intensity of the 002 peak.
  • Degree of graphitization Using high-purity silicon powder as the standard sample, the graphite sample and the silicon standard sample are mixed in a weight ratio of 5:1, and the 002 peak of graphite and the 111 peak of silicon are obtained by testing.
  • the calibrated 002 interplanar spacing d002 is indirectly calculated to obtain the degree of graphitization, the calculation formula 0.3440 represents the interlayer spacing of completely ungraphitized carbon, and 0.3354 represents the interlayer spacing of ideal graphite, both in nm.
  • An area of 100 ⁇ m ⁇ 100 ⁇ m was selected on the negative electrode active material layer, and the particles in this area were scanned by a laser confocal Raman spectrometer (Raman, HR Evolution, HORIBA Scientific Instrument Division), and all the particles in the area were obtained.
  • the D1 peak, D2 peak and G peak of the particles are processed by LabSpec software to obtain the peak intensities of the D1 peak, D2 peak and G peak of each particle, which are Id1, Id2 and Ig respectively, and Id1/Ig is in steps of 0.02 Count the frequency of Id1/Ig for a long time to obtain a normal distribution map, count the (Id1/Ig)max and (Id1/Ig)min of these particles, calculate the average value of Id1/Ig and Id2/Ig and the variance of Id1/Ig, pull The laser wavelength of the Mann spectrometer can be in the range of 532nm to 785nm.
  • FIG. 2 shows the Raman test spectrum of the negative electrode active material in Example 2 of the present application.
  • FIG. 3 shows the Id1/Ig distribution diagram of the negative electrode active material in Example 1 of the present application.
  • D1 peak generally around 1350cm -1 , caused by the radial breathing mode of the symmetrical stretching vibration of the sp carbon atom in the aromatic ring ( structural defect);
  • D2 peak generally around 1620cm -1 , it appears with the D1 peak, which is related to the E 2g vibration of the graphite layer on the surface, and is used to characterize the regularity of the arrangement of the graphite crystallite structure;
  • the G peak appears around 1580 cm -1 , caused by the stretching vibration between sp carbon atoms, which corresponds to the vibration of the E 2g optical phonon in the center of the Brillouin zone (in- plane vibration of carbon atoms).
  • button battery Assemble the prepared negative electrode, lithium sheet, separator, electrolyte, steel sheet, nickel foam and button battery case together to obtain a button battery, and let it stand for 6 hours before testing.
  • Judgment of the degree of lithium precipitation It is judged according to the state of dismantling the negative electrode at full charge. When the negative electrode as a whole is golden yellow and the gray area is less than 2%, it is judged that no lithium is deposited; when most of the negative electrode is golden yellow, but there are Gray can be observed in some positions, and the gray area is between 2% and 20%, it is judged as slight lithium precipitation; when the negative part is gray, but some golden yellow can still be observed, and the gray area is between 20% and 60%, then It is judged to be lithium precipitation; when most of the negative electrode is gray, and the gray area is greater than 60%, it is judged to be severe lithium precipitation.
  • the lithium-ion battery was connected to the Bio-Logic VMP3B electrochemical workstation produced by the French company Bio-Roger for testing, with a frequency range of 30mHz to 50kHz and an amplitude of 5mV. After the data is collected, the impedance complex plane diagram is used to analyze the data, and the lithium ion liquid phase transfer impedance (Rion) is obtained.
  • Table 1 lists the performance parameters of graphite prepared from different types of raw materials under different graphitization temperature conditions.
  • the Dv50 of the examples and the comparative examples are both 11 ⁇ m, and the Dv99 are both 27 ⁇ m.
  • Needle coke 1 is HNP produced by the British company CONOCO
  • petroleum coke 1 is 4A coke produced by Sinopec
  • petroleum coke 2 is 4B grade petcoke produced by Sinopec
  • metallurgical coke 1 is metallurgical coke produced by Inner Mongolia Baotou Steel.
  • the graphite microcrystalline structure tends to be regular, the 002 peak becomes narrower and stronger, the half-peak width becomes smaller, the graphite layer spacing becomes smaller (d002 becomes smaller), and the graphite layers are stacked more along the c-axis direction ( Lc increases) and extends in the a-axis direction (La increases), so the degree of graphitization increases, the position of lithium insertion increases, and the gram capacity increases.
  • Comparative Example 1 Compared with Example 1, Example 5 and Example 7, Comparative Example 1 was graphitized at a higher temperature, and the half-peak width and graphite interlayer spacing (d002) of the prepared samples were still larger than the optimal range , while La and Lc are less than the optimal range, and the gram capacity of the prepared graphite is only 333.9mAh/g, which cannot meet the requirement of high energy density.
  • Comparative Example 2 has a low graphitization temperature, resulting in a small microcrystalline structure of the finally prepared graphitized graphite, low crystallite regularity, large half-peak width of the 002 peak, and large interlayer spacing. , the lithium storage site is insufficient, thereby affecting the gram capacity of graphite.
  • Table 2 lists the relevant performance parameters of graphite and lithium ion batteries in the relevant examples and comparative examples.
  • the preparation methods of Examples 8 to 18 are the same as those of Example 4, except that the data shown in Table 2 are graphitized.
  • the temperature was 2800°C.
  • the Dv50 of graphite is 7 ⁇ m to 14 ⁇ m
  • the Dv99 of graphite is in the range of 25 ⁇ m to 45 ⁇ m
  • the tap density is ⁇
  • the capacity, first effect, lithium evolution at 0.8C, and liquid phase transfer impedance of the battery are in a relatively balanced range.
  • the Dv99 of graphite is 27 ⁇ m to 39 ⁇ m, the battery performance is better, which may be because in the graphitization process, the larger particle size of the raw material is easy to form a more regular structure of graphite microcrystalline structure, with high tap density and more intercalation.
  • SEI solid electrolyte membrane
  • Example 17 Comparing Example 17 and Example 16, the graphite Dv50 decreases, the battery gram capacity and the first effect decrease, which may be because the smaller graphite Dv50 consumes more lithium ions to form the SEI film, so the first effect decreases.
  • Example 18 Comparing Example 8 with Example 8, the particle size of the graphite Dv50 particles in Example 18 is significantly larger than that in Example 8, and the gram capacity and total capacitance are higher than those in Example 8.
  • the large particle size will increase the path of lithium ion deintercalation, so the kinetic performance is poor (lithium precipitation), and the liquid phase transfer impedance is large, so it is necessary to control the Dv50 and Dv99 of the particles within the appropriate range, so that A more balanced performance can be obtained.
  • Table 3 lists the performance parameters of graphite and lithium ion batteries in the relevant examples and comparative examples.
  • the specific graphitization temperature is shown in Table 3.
  • the negative electrode active material defect distribution (Id1/Ig) max -(Id1/Ig) min is controlled within the range of 0.2-0.7, and the variance value of the defect distribution is controlled within the range of 0.04-0.15,
  • the average value of Id2/Ig is controlled in the range of 0.05-0.15, and the porosity of the negative electrode is controlled in the range of 20%-35%, so that a good rate of lithium intercalation and deintercalation is maintained in the range of higher lithium intercalation capacity. This may be due to the fact that the degree of defects and disorder on the surface of graphite materials are negatively correlated with the capacity exerted by graphite in batteries, but positively correlated with the rate of lithium ion transport.
  • controlling the defect content on the surface of the negative active material within a certain range can balance the capacity loss and maintain the energy density on the one hand, and improve the kinetic performance on the other hand.
  • the porosity of the negative electrode is controlled within a certain range, which is conducive to the infiltration of the electrolyte into the negative electrode, thereby facilitating the deintercalation of lithium ions and improving the lithium precipitation.
  • (Id1/Ig) max -(Id1/Ig) min is the difference between the maximum value and the minimum value of Id1/Ig at all points measured in the range of 100 ⁇ m ⁇ 100 ⁇ m on the negative electrode. The larger the difference, the higher the defect content. The more, and the distribution is uneven.
  • STEDV(Id1/Ig) is expressed as the deviation degree of defect content relative to the average value in this range. The larger the deviation degree is, the more uneven the defect distribution is.
  • (Id1/Ig) max -(Id1/Ig) min and STEDV(Id1/Ig) increase, there are some heteroatoms that cannot be removed, so they remain on the surface of the graphite layer. More SEI film, therefore lower first effect.
  • the existence of defects is conducive to the transfer of lithium ions, so the liquid phase transfer coefficient is small, and the lithium precipitation is good. Therefore, it is necessary to control (Id1/Ig) max -(Id1/Ig) min and STEDV(Id1/Ig) within an appropriate range, so that the battery can obtain balanced performance.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Battery Electrode And Active Subsutance (AREA)

Abstract

La présente demande concerne un matériau actif d'électrode négative, une électrode négative le comprenant, un dispositif électrochimique et un dispositif électronique. Le matériau actif d'électrode négative comprend du graphite, la largeur de pic à mi-hauteur du (002) pic de diffraction du plan de cristallisation du graphite se situant dans une plage de 0,260° à 0,300°, telle que mesurée par un procédé par diffraction des rayons X. Le dispositif électrochimique préparé avec le matériau actif d'électrode négative de la présente demande présente une rétention de capacité et une densité d'énergie supérieures, ainsi qu'une performance dynamique améliorée.
PCT/CN2021/074629 2021-02-01 2021-02-01 Matériau actif d'électrode négative, électrode négative le comprenant, dispositif électrochimique et dispositif électronique WO2022160332A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
PCT/CN2021/074629 WO2022160332A1 (fr) 2021-02-01 2021-02-01 Matériau actif d'électrode négative, électrode négative le comprenant, dispositif électrochimique et dispositif électronique
CN202310887591.8A CN116885176A (zh) 2021-02-01 2021-02-01 电化学装置和包含其的电子装置
CN202180003010.9A CN113795947B (zh) 2021-02-01 2021-02-01 负极活性材料及包含其的负极、电化学装置和电子装置

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2021/074629 WO2022160332A1 (fr) 2021-02-01 2021-02-01 Matériau actif d'électrode négative, électrode négative le comprenant, dispositif électrochimique et dispositif électronique

Publications (1)

Publication Number Publication Date
WO2022160332A1 true WO2022160332A1 (fr) 2022-08-04

Family

ID=78877401

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/074629 WO2022160332A1 (fr) 2021-02-01 2021-02-01 Matériau actif d'électrode négative, électrode négative le comprenant, dispositif électrochimique et dispositif électronique

Country Status (2)

Country Link
CN (2) CN113795947B (fr)
WO (1) WO2022160332A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116706076A (zh) * 2023-08-09 2023-09-05 宁德新能源科技有限公司 一种负极材料、负极极片、电化学装置及电子装置

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114784228B (zh) * 2022-06-24 2022-10-11 宁德新能源科技有限公司 二次电池及电子装置
WO2024065595A1 (fr) * 2022-09-30 2024-04-04 宁德新能源科技有限公司 Matériau d'électrode négative, batterie secondaire et dispositif électronique
CN117882216A (zh) * 2022-09-30 2024-04-12 宁德新能源科技有限公司 负极材料、二次电池和电子装置
CN117976888B (zh) * 2024-03-28 2024-06-07 溧阳紫宸新材料科技有限公司 一种负极材料及其制备方法和二次电池

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109841831A (zh) * 2019-03-21 2019-06-04 宁德新能源科技有限公司 负极材料及包含该负极材料的负极及电化学装置
CN111354944A (zh) * 2020-03-20 2020-06-30 宁德新能源科技有限公司 负极活性材料及使用其的电化学装置和电子装置
CN111370695A (zh) * 2020-03-20 2020-07-03 宁德新能源科技有限公司 负极活性材料及使用其的电化学装置和电子装置

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109841831A (zh) * 2019-03-21 2019-06-04 宁德新能源科技有限公司 负极材料及包含该负极材料的负极及电化学装置
CN111354944A (zh) * 2020-03-20 2020-06-30 宁德新能源科技有限公司 负极活性材料及使用其的电化学装置和电子装置
CN111370695A (zh) * 2020-03-20 2020-07-03 宁德新能源科技有限公司 负极活性材料及使用其的电化学装置和电子装置

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
DORON AURBACH, Z HANAN TELLER, AND ELENA LEVI: "Morphology/Behavior Relationship in Reversible Electrochemical Lithium Insertion into Graphitic Materials", JOURNAL OF THE ELECTROCHEMICAL SOCIETY, vol. 149, no. 10, 13 August 2002 (2002-08-13), pages A1255 - A1266, XP055953648, ISSN: 0013-4651 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116706076A (zh) * 2023-08-09 2023-09-05 宁德新能源科技有限公司 一种负极材料、负极极片、电化学装置及电子装置
CN116706076B (zh) * 2023-08-09 2023-12-19 宁德新能源科技有限公司 一种负极材料、负极极片、电化学装置及电子装置

Also Published As

Publication number Publication date
CN116885176A (zh) 2023-10-13
CN113795947B (zh) 2023-08-11
CN113795947A (zh) 2021-12-14

Similar Documents

Publication Publication Date Title
WO2020187106A1 (fr) Matériau d'anode, anode et dispositif électrochimique comprenant ce matériau d'anode
WO2022160332A1 (fr) Matériau actif d'électrode négative, électrode négative le comprenant, dispositif électrochimique et dispositif électronique
WO2021184532A1 (fr) Matériau actif d'électrode négative, dispositif électrochimique l'utilisant et appareil électronique
TWI620372B (zh) 鋰離子蓄電池用負極材料，鋰離子蓄電池用負極及鋰離子蓄電池
WO2022268046A1 (fr) Matériau actif d'électrode négative, batterie secondaire et dispositif électronique
CN113097438B (zh) 电化学装置和电子装置
WO2021185014A1 (fr) Matériau actif d'électrode négative ainsi que dispositif électrochimique et dispositif électronique l'utilisant
CN116093316B (zh) 负极活性材料及其制备方法、负极极片和二次电池
CN113948675B (zh) 一种电化学装置和电子装置
WO2022206175A1 (fr) Électrode négative, dispositif électrochimique la comprenant et dispositif électronique
CN113161532A (zh) 负极活性材料及包含该负极活性材料的负极、二次电池和电子设备
CN115425215A (zh) 复合材料及其制备方法、电化学装置及电子装置
JP2012079470A (ja) 非水電解質二次電池
JP7273182B2 (ja) 複合黒鉛材料、二次電池、装置及び製造方法
WO2023122855A1 (fr) Dispositif électrochimique et dispositif électronique
CN112421031B (zh) 电化学装置和电子装置
WO2023184080A1 (fr) Appareil électrochimique et appareil électronique
WO2023097458A1 (fr) Dispositif électrochimique et dispositif électronique
JP7471738B2 (ja) 負極活物質、これを含む負極および二次電池
CN112886002B (zh) 电化学装置和包含其的电子设备
WO2024065597A1 (fr) Matériau d'électrode négative, batterie rechargeable et appareil électrique
WO2024007184A1 (fr) Accumulateur et appareil électronique
WO2023142029A1 (fr) Matériau actif d'électrode positive, dispositif électrochimique comprenant un matériau actif d'électrode positive, et dispositif électronique
WO2023108397A1 (fr) Matériau actif d'électrode positive, dispositif électrochimique et dispositif électronique
WO2021134755A1 (fr) Électrode négative, appareil électrochimique la comprenant et dispositif électronique

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: 21921932

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21921932

Country of ref document: EP

Kind code of ref document: A1