WO2020005702A1 - Cathodes pour batteries au lithium-soufre à l'état solide et leurs procédés de fabrication - Google Patents

Cathodes pour batteries au lithium-soufre à l'état solide et leurs procédés de fabrication Download PDF

Info

Publication number
WO2020005702A1
WO2020005702A1 PCT/US2019/038195 US2019038195W WO2020005702A1 WO 2020005702 A1 WO2020005702 A1 WO 2020005702A1 US 2019038195 W US2019038195 W US 2019038195W WO 2020005702 A1 WO2020005702 A1 WO 2020005702A1
Authority
WO
WIPO (PCT)
Prior art keywords
sulfur
cathode
range
composite layer
layer
Prior art date
Application number
PCT/US2019/038195
Other languages
English (en)
Inventor
Michael Edward Badding
Jun Jin
Yang Lu
Zhen Song
Zhaoyin Wen
Tongping XIU
Original Assignee
Corning Incorporated
Shanghai Institute Of Ceramics, Chinese Academy Of Sciences
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
Priority claimed from CN201811325286.5A external-priority patent/CN111162242A/zh
Application filed by Corning Incorporated, Shanghai Institute Of Ceramics, Chinese Academy Of Sciences filed Critical Corning Incorporated
Priority to US17/255,274 priority Critical patent/US20210111400A1/en
Publication of WO2020005702A1 publication Critical patent/WO2020005702A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • 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
    • H01M4/136—Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
    • 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
    • H01M4/139—Processes of manufacture
    • H01M4/1397—Processes of manufacture of electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H01M4/364—Composites as mixtures
    • 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
    • H01M4/581—Chalcogenides or intercalation compounds thereof
    • H01M4/5815—Sulfides
    • 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
    • H01M4/60—Selection of substances as active materials, active masses, active liquids of organic compounds
    • H01M4/602—Polymers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • 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
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/028—Positive electrodes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • Li-S batteries are promising candidates for replacing conventional lithium-ion batteries since they are cheaper, weigh less, and can store nearly double the energy for the same mass.
  • Li-S cell chemistries have a high energy density (e.g., 2600 W'h'kg 1 ) and theoretical specific capacity (e.g., 1675 mA'h'g 1 ), natural abundance and is environmentally friendly.
  • the present application discloses improved cathodes and methods of formation thereof for solid-state lithium sulfur (Li-S) battery applications.
  • a cathode for a lithium-sulfur battery comprises: a sulfur-based composite layer having a porosity in a range of 60% to 99%; and a conductive polymer disposed atop the composite layer and within pores of the composite layer.
  • the composite layer has a porosity in a range of 60% to 80%.
  • the pores of the composite layer have a size in a range of 1 pm to 50 pm.
  • the pore size is in a range of 2 pm to 10 pm.
  • the composite layer comprises a carbon material present as at least one of nanoparticles, nanowires, nanofibers, nanorods, nanotubes, nanospheres, graphene, or combinations thereof.
  • the carbon material is present in a range of 5 wt.% to 40 wt.%.
  • the composite layer comprises a metal carbide in a range of 1 wt.% to 20 wt.%.
  • the conductive polymer comprises at least one of carbon polysulfides (CS), polyethylene oxides (PEO), polyaniline (PANI), polypyrrole (PPY), poly(3, 4-ethyl enedioxythiophene) (PEDOT), polystyrenesulfonic acid (PSS), polyacrylonitrile (PAN), polyacrylic acid (PAA), polyallylamine hydrochloride (PAH), poly(vinylidene fluoride-co-hexafluoropropylene) (P(VdF-co-HFP)), poly(methylmethacrylate) (PMMA), polyvinylidene fluoride (PVDF), poly(diallyldimethyl ammonium) bis(trifluoromethanesulfonyl)imide (TFSI) (PDDATFSI), or combinations thereof and at least one of bis(trifluorom ethane) sulfon
  • CS carbon polysulfides
  • PEO polyethylene oxides
  • a lithium-sulfur (Li-S) battery comprises: a lithium anode; a solid-state electrolyte; and a cathode as disclosed herein.
  • the Li-S battery is configured to have a discharge capacity retention rate of at least 90%.
  • the solid-state electrolyte comprises at least one of: Li6 . 4La3Zr1 . 4Tao .
  • LiioGeP 2 Si 2 Lii.5Alo.5Gei.5(P04)3, Lii.4Alo.4Tii.6(P04)3, Lio.55Lao.3sTi03
  • interpenetrating polymer networks of poly(ethyl acrylate) (ipn-PEA) electrolyte three-dimensional ceramic/polymer networks, in-situ plasticized polymers, composite polymers with well-aligned ceramic nanowires, PEO-based solid-state polymers, flexible polymers, polymeric ionic liquids, in-situ formed L13PS4, or combinations thereof.
  • a method of forming a cathode for a lithium-sulfur battery comprises: providing a substrate; disposing a sulfur-based slurry layer on the substrate; freeze- drying the slurry layer to form a sulfur-based composite layer having a porosity in a range of 60% to 99%; and disposing a conductive polymer atop the composite layer and within pores of the composite layer.
  • the substrate is a current collector.
  • the method further comprises: mixing a metal carbide, carbon material, and sulfur material in a solvent to form a sulfur precursor; and dry milling the dry sulfur precursor to form a sulfur composite.
  • the method further comprises: agitating the sulfur composite with a binder to form the sulfur-based slurry.
  • the carbon material is at least one of: nanoparticles, nanowires, nanofibers, nanorods, nanotubes, nanospheres, graphene, or combinations thereof
  • the binder comprises at least one of styrene- butadiene rubber, carboxyl methyl cellulose, polyacrylic acid (PAA), sodium alginate, or combinations thereof.
  • the composite layer has a porosity in a range of 60% to 80%.
  • the pores of the composite layer have a size in a range of 1 pm to 50 pm.
  • the pore size is in a range of 2 pm to 10 pm.
  • the step of freeze-drying comprises: freezing the slurry layer at a temperature in a range of -50°C and 0°C for a time in a range of 1 hr to 12 hrs; and drying the frozen slurry layer in a freeze drier for a time in a range of 1 hr to 24 hrs.
  • the step of disposing the conductive polymer is conducted by at least one of spin coating, dip coating, layer-by-layer deposition, sol-gel deposition, inkjet printing, or combinations thereof.
  • a method of forming a lithium-sulfur (Li-S) battery comprising: providing a substrate; providing a cathode formed by: disposing a sulfur-based slurry layer on the substrate; freeze-drying the slurry layer to form a sulfur-based composite layer having a porosity in a range of 60% to 99%; and disposing a conductive polymer atop the composite layer and within pores of the composite layer; providing a solid-state electrolyte; and providing a lithium anode.
  • FIG. 1 illustrates a structure of a solid-state lithium sulfur (Li-S) battery, according to some embodiments.
  • FIG. 2 illustrates a scheme of Li-S sulfur cathode dried by (a) heat drying; and (b) freeze drying.
  • FIG. 3 illustrates (a) surface and (b) cross-sectional scanning electron microscopy (SEM) images of a cathode electrode, as in comparative example 1.
  • FIG. 4 illustrates cross-sectional SEM images and corresponding energy dispersive spectroscopy (EDS) mapping of cathode samples (coated with PEO), as in comparative example 1
  • FIG. 5 illustrates (a) surface and (b) cross-sectional SEM images of a cathode electrode; and (c) surface and (d) cross-sectional SEM images of cathode samples coated with a PEO-based electrolyte layer, as in example 1.
  • FIG. 6 illustrates cross-sectional SEM images and corresponding EDS mapping of cathode samples (coated with PEO), as in example 1.
  • FIG. 8 illustrates cycling performance of a Li-S battery having a cathode prepared by (I) freeze-drying or (II) heat-drying.
  • FIG. 9 illustrates charge-discharge curves of Li-S batteries having sulfur cathodes prepared by (a) heat drying; and (b) freeze drying at a current density of 0.1 mA*cm 2 at 60°C.
  • FIG. 10 illustrates cycling performance of Li-S batteries with a cathode prepared by freeze-drying and an Li-Au anode, as in Example 2.
  • the present disclosure relates to solid-state lithium sulfur batteries, and more particularly, to sulfur cathodes and their method of production, in which a lithium ion conductive polymer layer (e.g., polyethylene oxide (PEO)) coated porous sulfur cathode is used for solid- state lithium sulfur batteries.
  • a lithium ion conductive polymer layer e.g., polyethylene oxide (PEO) coated porous sulfur cathode is used for solid- state lithium sulfur batteries.
  • FIG. 1 illustrates an example of a solid-state lithium sulfur (Li-S) battery structure, according to some embodiments. It will be understood by those of skill in the art that the processes described herein can be applied to other configurations of solid-state lithium sulfur (Li- S) battery structures.
  • battery 100 may include a substrate 102 (e.g., a current collector), a sulfur electrode (e.g., cathode) 104 disposed on the substrate, a first interlayer 106 disposed on the cathode, a solid-state electrolyte 108 disposed on the first interlayer, a second interlayer 110 disposed on the electrolyte, and a lithium electrode (e.g., anode) 112 disposed on the second interlayer.
  • substrate 102 e.g., a current collector
  • sulfur electrode e.g., cathode
  • first interlayer 106 disposed on the cathode
  • solid-state electrolyte 108 disposed on the first interlayer
  • second interlayer 110 disposed on the electrolyte
  • a lithium electrode e.g., anode
  • the substrate 102 may a current collector including at least one of three-dimensional nickel (Ni) foam, carbon fiber, foils (e.g., aluminum, stainless steel, copper, platinum, nickel, etc.), or a combination thereof.
  • the interlayer 106 and 110 may be independently chosen from at least one of carbon-based interlayers (e.g., interlinked freestanding, micro/mesopore containing, functionalized, biomass derived), polymer-based interlayers (e.g., PEO, polypyrrole (PPY), polyvinylidene fluoride, etc.), metal-based (e.g., Ni foam, etc.), or a combination thereof.
  • carbon-based interlayers e.g., interlinked freestanding, micro/mesopore containing, functionalized, biomass derived
  • polymer-based interlayers e.g., PEO, polypyrrole (PPY), polyvinylidene fluoride, etc.
  • metal-based e.g., Ni foam, etc.
  • solid-state electrolyte 108 may be used to address common safety concerns such as leakage, poor chemical stability, and flammability often seen in Li-S batteries employing liquid electrolytes. Moreover, solid-state electrolytes can also suppress polysulfide shuttling from the cathode to the anode, thereby leading to improved cathode utilization and a high discharge capacity and energy density.
  • the solid-state electrolyte may include at least one of Li 6.4 La3Zr1.4Tao.
  • the anode 112 may comprise lithium (Li) metal.
  • the battery may include at least one anode protector such as electrolyte additives (e.g., L1NO 3 , lanthanum nitrate, copper acetate, P 2 S 5 , etc.), artificial interfacial layers (e.g., Li 3 N, (CFffSiCl, AI2O3, LiAl, etc.), composite metallics (e.g., L17B6, Li-rGO (reduced graphene oxide), layered Li-rGO, etc.), or combinations thereof.
  • electrolyte additives e.g., L1NO 3 , lanthanum nitrate, copper acetate, P 2 S 5 , etc.
  • artificial interfacial layers e.g., Li 3 N, (CFffSiCl, AI2O3, LiAl, etc.
  • composite metallics e.g., L17B6, Li-rGO (reduced graphene oxide),
  • FIG. 2 illustrates a scheme 200 of Li-S sulfur cathode dried by (a) heat drying; and (b) freeze drying.
  • a current collector substrate 206 is coated with a sulfur-based slurry layer comprising binder 202 and sulfur composite 204.
  • the slurry layer may be formed as follows. Initially, a metal carbide, carbon material, and sulfur material is mixed in a solvent to form a sulfur precursor.
  • the metal carbide may be a carbide comprising at least one of tungsten (W), iron (Fe), chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), molybdenum (Mo), sodium (Na), calcium (Ca), or a combination thereof.
  • the carbon material may be at least one of nanoparticles, nanowires, nanofibers, nanorods, nanotubes, nanospheres, graphene, or combinations thereof.
  • the sulfur material is elemental sulfur.
  • the solvent may be any known compatible solvent such as at least one of water, hexane, octane, acetone, tetrahydrofuran, 2-butanone, toluene, xylene, ethanol, methanol, isopropanol, benzene, or combinations thereof.
  • the mixing may be conducted by at least one of ball milling, sonication, magnetic mixing, vortex mixing, etc.
  • the sulfur precursor may be milled (e.g., dry milling, etc.) to form a sulfur composite, which is then mixed and agitated with a binder to form the sulfur-based slurry.
  • the binder includes at least one of styrene-butadiene rubber, carboxyl methyl cellulose, polyacrylic acid (PAA), sodium alginate, or combinations thereof.
  • the binder includes styrene-butadiene rubber and carboxyl methyl cellulose.
  • the binder includes water.
  • the slurry having the sulfur composite 204 and binder 202 is then positioned onto the substrate 206 by at least one of spin coating, dip coating, layer-by-layer deposition, sol-gel deposition, inkjet printing, or combinations thereof.
  • the slurry layer is heat dried, as in route (a) of FIG. 2.
  • the dense packing structure 208 results in a lower available internal volume space (i.e., lower porosity, fewer irregular pores) within the composite layer for incorporation of a subsequently formed conductive polymer.
  • the slurry layer is freeze-dried to form a sulfur-based composite layer 210 having a porosity in a range of 60% to 99%.
  • the structure of sulfur cathode may be held by freezing the solvent in the slurry layer at low temperatures before drying. Pores are formed in the composite layer as the frozen solvent sublimes during the drying (i.e., pores remain in the at the position where the solvent was originally located). In other words, during the process of freeze-drying, internal volume space of the composite layer occupied by the solvent may be retained, thereby avoiding shrinkage of the composite layer caused by the volatilization of the solvent during the drying process. Compared with traditional heat drying, freeze-drying may increase composite layer porosity by 3-5x.
  • the composite layer has a porosity in a range of 60% to 80% (as compared with porosity of the heat-dried slurry layer, which has a porosity in a range of 30% to 50%).
  • pores of the composite layer may have a size in a range of 1 pm to 50 pm.
  • the pores may have a range of 2 pm to 10 pm.
  • the freezing is conducted at a temperature in a range of -50°C and 0°C, or in a range of -35°C and - l0°C, or in a range of -25°C and -l5°C. In some examples, the freezing is conducted at a temperature of -20°C.
  • the freezing is conducted for a time in a range of 1 hr to 12 hrs, or in a range of 2 hrs to 9 hrs, or in a range of 4 hrs to 7 hrs. In some examples, the freezing is conducted for a time of 6 hrs. In some examples, the freezing is conducted at a temperature of -20°C for a time of 6 hrs. In some examples, the drying is conducted in a freeze drier for a time in a range of 1 hr to 24 hrs, or in a range of 6 hrs to 18 hrs, or in a range of 9 hrs to 15 hrs. In some examples, the drying is conducted for a time of 12 hrs.
  • the composite layer includes carbon material in a range of 5 wt.% to 40 wt.%, or in a range of 10 wt.% to 30 wt.%, or in a range of 15 wt.% to 25 wt.%.
  • the composite layer includes metal carbide in a range of 1 wt.% to 20 wt.%, or in a range of 3 wt.% to 17 wt.%, or in a range of 5 wt.% to 15 wt.%.
  • the carbon material and metal carbide are conductive portions uniformly dispersed in the final sulfur cathode that aide in adsorbing polysulfide (i.e., minimizing polysulfide migration) to improve sulfur utilization (i.e., minimizing loss of active cathode material).
  • a conductive polymer 212 is disposed atop the composite layer 210 and within pores of the composite layer 210 by at least one of spin coating, dip coating, layer-by-layer deposition, sol -gel deposition, inkjet printing, or combinations thereof to achieve the final cathode structure 214.
  • the conductive polymer comprises at least one of carbon polysulfides (CS), polyethylene oxides (PEO), polyaniline (PANI), polypyrrole (PPY), poly(3, 4-ethyl enedioxythiophene) (PEDOT), polystyrenesulfonic acid (PSS),
  • PAN polyacrylonitrile
  • PAA polyacrylic acid
  • PAH polyallylamine hydrochloride
  • PVdF-co-HFP poly(vinylidene fluoride-co-hexafluoropropylene)
  • PMMA poly(methylmethacrylate)
  • PVDF polyvinylidene fluoride
  • TFSI bis(trifluoromethanesulfonyl)imide
  • PDDATFSI bis(trifluorom ethane) sulfonimide lithium salt
  • LiTFSI bis(trifluorom ethane) sulfonimide lithium salt
  • LiBOB lithium bis(oxalato) borate
  • LiFSI lithium bis(fluorosulfonyl)imide
  • the conductive polymer is a polyethylene oxide. Because freeze- drying creates pores and pathways within the interior of the composite layer, the conductive polymer slurry (e.g., PEO electrolyte) is able to penetrate into the composite layer through its porous structure after it has been coated onto the surface of the composite layer. This surface coating and internal penetration improves interfacial compatibility and enhances ionic conductivity of the resultant sulfur electrode.
  • the conductive polymer slurry e.g., PEO electrolyte
  • Sulfur, tungsten carbide (WC) and vapor-growth carbon fiber (VGCF) are ball-milled at a weight ratio of 6:2:2 in ethanol. After ball-milling for 4 hours, the mixed powder is filtered and dried. After an additional dry grinding (e.g., dry milling) for 24 hrs, the mixture is sieved to form a sulfur composite.
  • a slurry is prepared by ball-milling or stirring a mixture comprising the previously-prepared sulfur composite, tungsten carbide (WC), vapor-growth carbon fiber (VGCF), styrene-butadiene rubber (SBR), and carboxyl methyl cellulose (CMC) at a weight ratio of 80:5:5:5:5. Thereafter, the slurry was coated on an aluminum foil having a thickness of 100 pm.
  • the slurry-coated aluminum foil was then frozen at -20°C for about 6 hrs, and then positioned in a freeze drier for approximately 12 hrs to purge the water content in the slurry.
  • the electrode was diced into 12 mm diameter disks.
  • the sulfur content of the cathode was measured at about 1.78 mg/cm 2 .
  • Polyethylene oxide (PEO) powder and bis(trifluorom ethane) sulfonimide lithium salt (LiN(CF 3 S0 2 ) 2 , or LiTFSI) are dissolved into acetonitrile at a mole ratio of PEO to Li + of about 18: 1.
  • the solid content of the slurry is about 10%.
  • This slurry is cast on the surface of the freeze-dried cathode and thereafter, the cathode is dried under vacuum at about 60°C where the solvent was volatilized to form the sulfur cathode.
  • the cathode is designed to have a thickness of less than 200 pm.
  • the final sulfur cathode is then assembled with other parts (e.g., interlayer, electrolyte, Li anode) into a battery.
  • the sample formed as comparative example 1 is prepared as provided above in example 1 except for the step of freeze-drying. Instead, after coating the slurry onto the aluminum foil, the structure was heat-dried in a furnace at a temperature of approximately 60°C to purge the water content in the slurry. Subsequently, the electrode was diced into 12 mm diameter disks.
  • FIG. 3 illustrates (a) surface (plane-view) and (b) cross-sectional SEM images of a cathode electrode, as in comparative example 1. Morphology analysis described herein was conducted by scanning electron microscopy (SEM, Hitachi JSM 6700) and element mapping images were characterized by an energy dispersive spectrometer (EDS) affiliated with the HITACHI SEM. As is seen in FIGS. 3(a) and (b), furnace heat-drying resulted in sizeable particle agglomeration, with the agglomerated particles separating from the conductive network. For example, the initial coating thickness of the slurry on the aluminum foil was set at 100 pm. After the heat treatment at 60°C, the initial slurry film experienced significant decrease in thickness of about 70%, as the after heat drying thickness was measured to be about 30 pm.
  • SEM scanning electron microscopy
  • EDS energy dispersive spectrometer
  • the composite layer retains a lower porosity and the finally-formed cathode has a non-uniform thickness.
  • the heat treatment corresponds to a lower available internal volume space within the composite layer for incorporation of the conductive polymer.
  • FIG. 4 illustrates cross-sectional SEM images and corresponding energy dispersive spectroscopy (EDS) mapping of cathode samples coated with PEO conductive polymer (i.e.,
  • PEO electrolyte as in comparative example 1.
  • FIG. 1 As shown by the cross-sectional SEM image (top-left), upon application, though the surface of the sulfur electrode is completely covered by PEO electrolyte, there is a distribution gradient of oxygen in the electrode (as seen in the EDS mapping image, bottom-right). In other words, oxygen is concentrated towards a top surface of the electrode, without being able to sufficiently penetrate the electrode body. This is observed in the EDS image as bright luminescence where most of the oxygen is positioned (i.e., on the top surface of the electrode where the PEO electrolyte was deposited), followed by a sharp decline of luminescence with increasing depth into the electrode from the top surface.
  • FIG. 5 illustrates (a) surface and (b) cross-sectional SEM images of a cathode electrode; and (c) surface and (d) cross-sectional SEM images of cathode samples coated with a PEO-based electrolyte layer, as in example 1. Compared to results of the heat drying process as in FIGS.
  • FIGS. 3(a) and (b) agglomeration of particles is alleviated (FIGS. 5(a) and (b)) as the resulting cathode is relatively uniform with a smooth, homogenous surface and a high-conductive network (i.e., particles are connected with carbon nanofiber).
  • Cross-section comparisons between FIGS. 3(b) and 5(b) indicate a much less rough top surface for samples prepared by freeze drying as well as a greater thickness overall (30 pm for heat drying versus 80 pm for freeze drying), thereby suggesting a morphology with a lower degree of stacking and greater amount of open space (i.e., pore volume) in the body of the cathode.
  • FIG. 6 illustrates cross-sectional SEM images and corresponding EDS mapping of cathode samples coated with PEO electrolyte, as in example 1.
  • the surface of the sulfur electrode is completely covered by PEO electrolyte.
  • a uniform distribution of sulfur (top-right) and carbon (bottom-left) in the electrode demonstrates that the electrode prepared by freeze-drying does not exhibit particle agglomeration.
  • the oxygen more completely permeates axially through pores of the electrode, as well as providing a relatively uniform lateral distribution of the oxygen (bottom-right).
  • the oxygen element distribution in the electrode indicates that the PEO slurry may more fully infiltrate into the interior of the electrode (defined by a rich pore structure) prepared by freeze drying than when prepared by heat drying; thereby increasing the ion conductivity of the electrode.
  • PEO infiltration plays an essential role as an ionic conductive media among the electrolyte (e.g., PEO interlayer, solid-state electrolyte, etc.) and the active materials of the cathode.
  • the electrolyte e.g., PEO interlayer, solid-state electrolyte, etc.
  • PEO is added by a simple casting process and subsequent heat-drying.
  • the PEO slurry is not able to adequately permeate into the pores and other pathways of the sulfur electrode (e.g., structure 20 of FIG. 2) to form an effective ionic conductive path, thereby resulting in a poor utilization of the active materials.
  • Heat-dried prepared cathodes without adequate pore formation PEO infiltration still suffer from dissolution and migration of polysulfide through the PEO electrolyte at high temperatures (i.e., shuttling effect).
  • FIGS. 7 and 8 illustrate impedance plots and cycling performance, respectively, of a Li- S battery having a cathode prepared by freeze-drying and heat-drying.
  • Electrochemical impedance spectroscopy (EIS) was carried out on an Autolab electrochemical workstation (ECO CHEMIE B.V, Netherlands) with a frequency response analyzer. Because of the pore volume created in the cathode prepared by freeze drying and incorporation of conductive polymer (e.g., PEO), the PEO-based ionic conductor is better able to contact active materials, thereby resulting in a lower overall impedance of the solid-state lithium sulfur battery (60 W, versus 80 W for a heat-dried cathode).
  • conductive polymer e.g., PEO
  • the lower overall impedance due to PEO contact with the cathode active material effectively reduces charge transfer resistance.
  • the lower porosity of the cathode prepared by heating-drying is harmful to PEO electrolyte infiltration, which results in a high charge transfer resistance.
  • FIG. 8 illustrates cycling performance of Li-S batteries with a cathode prepared by freeze-drying and heat-drying processes.
  • the cathode prepared by heat-drying shows higher initial discharge capacity and poor cycling performance as compared with cathodes prepared by freeze-drying.
  • the higher initial discharge capacity of heat-dried cathode is due to a short charge transport path, which causes PEO to penetrate into contact with the active material during while resting.
  • the capacity of heat-dried cathode battery degrades with cycling due to the dissolution of the reaction product in the PEO layer.
  • the freeze-dried cathode demonstrates a relatively stable capacity with cycling due to a slow dissolution and diffusion of polysulfides from thick electrodes to PEO layer. Since a large amount of PEO electrolyte penetrates into the freeze-dried prepared cathode, the discharge product dissolved into the PEO which is still in contact with the conductive network of the electrode and therefore, the discharge product may be re-used.
  • FIG. 9 illustrates charge-discharge curves of Li-S batteries having sulfur cathodes prepared by (a) heat drying; and (b) freeze drying. Electrochemical performance for the solid- state lithium sulfur batteries were measured with a LAND CT2001 A battery test system in a voltage range of 3 V to 1.5 V under a current density of 0.1 mA*cm 2 at 60°C. Prior to testing, samples were allowed to stand at 70°C for a time of about 12 hours. The Li-S battery comprising the heat-dried cathode initially demonstrates a discharge capacity over 1200 mAhg 1 S in a first cycle; however, this specific capacity rapidly diminishes with additional cycles, as it decreases to approximately 800 mAhg 1 S at the tenth cycle.
  • the Li-S battery comprising the freeze-dried cathode initially demonstrates a discharge capacity over 1000 mAhg _1 S in a first cycle and is able to maintain this specific capacity even after ten cycles.
  • the Li-S battery having a freeze-dried cathode delivers reversible capacity at about 1000 mAhg 1 S for the first ten cycles, and because curves for the different cycles overlap with each other, this suggests a benefit of an enhanced cycling stability of the battery.
  • the slurry was prepared as described in Example 1, and thereafter, coated on an aluminum foil having a thickness of 150 pm.
  • the slurry-coated aluminum foil was then frozen at -20°C for about 6 hrs, and then positioned in a freeze drier for approximately 12 hrs to purge the water content in the slurry.
  • the electrode was diced into 2 cm x 2 cm segments.
  • the sulfur content of the cathode was measured at about 2.9 mg/cm 2 .
  • PEO powder and LiTFSI are dissolved into acetonitrile at a mole ratio of PEO to Li + of about 8: 1.
  • the solid content of the slurry is about 5%.
  • This slurry is cast on the surface of the freeze-dried cathode and thereafter, the cathode is dried under vacuum at about 60°C where the solvent was volatilized to form the sulfur cathode.
  • the cathode is designed to have a thickness of less than 200 pm.
  • PEO powder and LiTFSI are dissolved into acetonitrile at mole ratio of PEO to Li + of about 18: 1.
  • Ionic liquid and 10 wt.% of Si0 2 particles are added and fully mixed.
  • the concentration of silica particles in PEO is in a range of 1 wt.% to 15 wt.%, determined as a function of silica particle size.
  • the Si0 2 particles help to reduce the PEO crystallinity and improve Li + conductivity.
  • the interlayer electrolyte is obtained by pouring the resulting interlayer slurry mixture in to a polytetrafluoroethylene (PTFE) mold for vacuum drying.
  • PTFE polytetrafluoroethylene
  • the interlayer between the cathode and electrolyte reduces interfacial impedance.
  • the interlayer thickness is as thin as possible. In some examples, the thickness of the interlayer may be in a range of 5 pm to 50 pm.
  • Cubic phase Li6 . 4La3Zr1 . 4Tao . 6O12 (LLZTO) is synthesized from starting powders of LiOH H 2 0 (AR), La 2 0 3 (99.99% purity), Zr0 2 (AR), Ta 2 0 5 (99.99% purity) with stoichiometry ratio. A 2 wt.% excess amount of LiOH H 2 0 is added to compensate for lithium loss during sintering. Traces of moisture and adsorbed C0 2 were removed from La 2 0 3 by heat treatment at 900°C for about 12 hrs.
  • Raw materials were mixed via a wet grinding process where yttrium- stabilized zirconium oxide (YSZ) balls and isopropanol (IP A) were used as the milling media. Following a second mixing step, the mixture was dried and calcined at 950°C for about 6 hrs in an alumina crucible, and then calcined again at 950°C for about 6 hrs to obtain pure cubic garnet phase powder. Following the second calcination process, the powders were pressed into -16 mm diameter green pellets and sintered at l250°C for about 10 hrs covered with LLZTO powder having 10 wt.% Li excess in platinum crucibles. Well sintered pellets were polished at a thickness of approximately 0.8 mm.
  • YSZ yttrium- stabilized zirconium oxide
  • IP A isopropanol
  • Example 2 a thin layer of gold (Au) was ion-sputter coated on one side of the LLZTO ceramic for 10 minutes. The sample was then transferred into an argon filled glove box. A portion of the Li foil was melted by heating to at least 250°C. The melted lithium was then cast on a surface of the LLZTO pellet comprising the ion-sputter coated Au layer. The final sulfur cathode (as in Example 2) is then assembled with the interlayer and the LLZTO-Au-Li solid-state electrolyte into a battery.
  • Au gold
  • Obtained Li-S batteries obtained by the processes described herein are composed of PEO-coated, freeze-dried sulfur cathodes, with a PEO-based interlayer coated thereon, a LLZTO ceramic solid-state electrolyte, and a lithium metal anode.
  • the solid-state lithium sulfur battery is assembled in glove box filled with inert gas (Ar), with the structure as shown in FIG. 1 (sulfur cathode / interlayer 1 / LLZTO / interlayer 2 / lithium anode).
  • FIG. 1 sulfur cathode / interlayer 1 / LLZTO / interlayer 2 / lithium anode.
  • Example 10 illustrates cycling performance of a Li-S battery having a cathode prepared by freeze-drying and an Li-Au anode at a current density of 0.1 mA*cm 2 at 60°C (i.e., Example 2).
  • the solid-state Li-S battery shows an initial discharge capacity of 980 mAhg 1 and good cycling performance. After 30 cycles, the Li-S battery maintains a discharge capacity of 888 mAhg 1 , which delivers a 90% capacity retention rate.
  • this disclosure relates to solid-state lithium sulfur batteries, and more particularly, to sulfur cathodes and their method of production, in which a lithium ion conductive polymer layer-coated porous sulfur cathode is used for solid-state lithium sulfur batteries.
  • the freeze-drying process disclosed herein generates a more porous and uniform sulfur electrode, as compared with traditional heat-drying prepared cathodes.
  • this enhanced porous electrode structure helps in penetration of PEO electrolyte into the cathode, thereby allowing excellent contact between the cathode active material, conductive carbon, and ionic conductive network, as well as increasing the utilization ratio of the sulfur active material.
  • the PEO electrolyte coating may also improve the interface stress and reduce the interface resistance. Therefore, the Li-S battery made from the S-cathode formed from the methods presented here has a higher reversible specific capacity, lower overall impedance, and more stable cycling performance, as compared with Li-S batteries formed with heat-drying prepared cathodes.

Abstract

Une cathode pour une batterie au lithium-soufre comprend une couche composite à base de soufre ayant une porosité dans une plage de 60 % à 99 % ; et un polymère conducteur disposé au-dessus de la couche composite et à l'intérieur des pores de la couche composite. De plus, un procédé de formation d'une cathode pour une batterie au lithium-soufre comprend l'utilisation d'un substrat ; la disposition d'une couche de bouillie à base de soufre sur le substrat ; la lyophilisation de la couche de bouillie pour former une couche composite à base de soufre ayant une porosité dans une plage de 60 % à 99 % ; et la disposition d'un polymère conducteur au-dessus de la couche composite et à l'intérieur des pores de la couche composite.
PCT/US2019/038195 2018-06-25 2019-06-20 Cathodes pour batteries au lithium-soufre à l'état solide et leurs procédés de fabrication WO2020005702A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US17/255,274 US20210111400A1 (en) 2018-06-25 2019-06-20 Cathodes for solid-state lithium sulfur batteries and methods of manufacturing thereof

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US201862689546P 2018-06-25 2018-06-25
US62/689,546 2018-06-25
CN201811325286.5A CN111162242A (zh) 2018-11-08 2018-11-08 固态锂硫电池的阴极及其制造方法
CN201811325286.5 2018-11-08

Publications (1)

Publication Number Publication Date
WO2020005702A1 true WO2020005702A1 (fr) 2020-01-02

Family

ID=67211926

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2019/038195 WO2020005702A1 (fr) 2018-06-25 2019-06-20 Cathodes pour batteries au lithium-soufre à l'état solide et leurs procédés de fabrication

Country Status (2)

Country Link
TW (1) TW202002365A (fr)
WO (1) WO2020005702A1 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020214570A1 (fr) * 2019-04-18 2020-10-22 Corning Incorporated Cathodes modifiées pour batteries au lithium-soufre à l'état solide et leurs procédés de fabrication
CN112086619A (zh) * 2020-09-29 2020-12-15 珠海冠宇电池股份有限公司 全固态锂电池正极片及其制备方法以及全固态锂电池
CN113381055A (zh) * 2020-03-10 2021-09-10 中国科学院上海硅酸盐研究所 一种低界面阻抗的锂/石榴石基固态电解质界面及其制备方法
WO2021252435A1 (fr) * 2020-06-11 2021-12-16 Corning Incorporated Cathode modifiée pour batterie au lithium-ion haute tension et procédé de fabrication associé
CN114388745A (zh) * 2022-03-09 2022-04-22 中南大学 一种高性能锂离子电池自支撑聚合物厚极片及其制备方法
CN116705989A (zh) * 2023-07-31 2023-09-05 山东硅纳新材料科技有限公司 柔性的聚合物电解质硅一体化电极及其制备方法与应用

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20150349307A1 (en) * 2014-05-27 2015-12-03 GM Global Technology Operations LLC Method for preparing a coated lithium battery component
US20170062869A1 (en) * 2015-08-24 2017-03-02 Aruna Zhamu Rechargeable lithium batteries having an ultra-high volumetric energy density and required production process
US20170207484A1 (en) * 2016-01-15 2017-07-20 Aruna Zhamu Alkali Metal-Sulfur Batteries Having High Volumetric and Gravimetric Energy Densities
KR20170112202A (ko) * 2016-03-31 2017-10-12 서울대학교산학협력단 고분자 막에 의하여 표면-코팅된 전극, 이의 제조 방법, 및 이를 포함하는 이차 전지

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20150349307A1 (en) * 2014-05-27 2015-12-03 GM Global Technology Operations LLC Method for preparing a coated lithium battery component
US20170062869A1 (en) * 2015-08-24 2017-03-02 Aruna Zhamu Rechargeable lithium batteries having an ultra-high volumetric energy density and required production process
US20170207484A1 (en) * 2016-01-15 2017-07-20 Aruna Zhamu Alkali Metal-Sulfur Batteries Having High Volumetric and Gravimetric Energy Densities
KR20170112202A (ko) * 2016-03-31 2017-10-12 서울대학교산학협력단 고분자 막에 의하여 표면-코팅된 전극, 이의 제조 방법, 및 이를 포함하는 이차 전지

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
HONG-JIE PENG ET AL: "A review of flexible lithium-sulfur and analogous alkali metal-chalcogen rechargeable batteries", CHEMICAL SOCIETY REVIEWS, vol. 46, no. 17, 1 January 2017 (2017-01-01), UK, pages 5237 - 5288, XP055616437, ISSN: 0306-0012, DOI: 10.1039/C7CS00139H *
SUN MINGHUI ET AL: "Hierarchically porous materials: Synthesis strategies and emerging applications", FRONTIERS OF CHEMICAL SCIENCE AND ENGINEERING, HIGHER EDUCATION PRESS, HEIDELBERG, vol. 10, no. 3, 21 August 2016 (2016-08-21), pages 301 - 347, XP036039158, ISSN: 2095-0179, [retrieved on 20160821], DOI: 10.1007/S11705-016-1578-Y *
ZHANG X ET AL: "Advances in lithium-sulfur batteries", MATERIALS SCIENCE AND ENGINEERING: R: REPORTS, vol. 121, 1 January 2017 (2017-01-01), pages 1 - 29, XP085238437, ISSN: 0927-796X, DOI: 10.1016/J.MSER.2017.09.001 *
ZHEN LI ET AL: "Status and prospects in sulfur-carbon composites as cathode materials for rechargeable lithium-sulfur batteries", CARBON., vol. 92, 1 October 2015 (2015-10-01), GB, pages 41 - 63, XP055390215, ISSN: 0008-6223, DOI: 10.1016/j.carbon.2015.03.008 *

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020214570A1 (fr) * 2019-04-18 2020-10-22 Corning Incorporated Cathodes modifiées pour batteries au lithium-soufre à l'état solide et leurs procédés de fabrication
CN113381055A (zh) * 2020-03-10 2021-09-10 中国科学院上海硅酸盐研究所 一种低界面阻抗的锂/石榴石基固态电解质界面及其制备方法
CN113381055B (zh) * 2020-03-10 2022-11-11 中国科学院上海硅酸盐研究所 一种低界面阻抗的锂/石榴石基固态电解质界面及其制备方法
WO2021252435A1 (fr) * 2020-06-11 2021-12-16 Corning Incorporated Cathode modifiée pour batterie au lithium-ion haute tension et procédé de fabrication associé
CN112086619A (zh) * 2020-09-29 2020-12-15 珠海冠宇电池股份有限公司 全固态锂电池正极片及其制备方法以及全固态锂电池
CN112086619B (zh) * 2020-09-29 2021-09-28 珠海冠宇电池股份有限公司 全固态锂电池正极片及其制备方法以及全固态锂电池
CN114388745A (zh) * 2022-03-09 2022-04-22 中南大学 一种高性能锂离子电池自支撑聚合物厚极片及其制备方法
CN114388745B (zh) * 2022-03-09 2024-03-29 中南大学 一种高性能锂离子电池自支撑聚合物厚极片及其制备方法
CN116705989A (zh) * 2023-07-31 2023-09-05 山东硅纳新材料科技有限公司 柔性的聚合物电解质硅一体化电极及其制备方法与应用
CN116705989B (zh) * 2023-07-31 2023-10-24 山东硅纳新材料科技有限公司 柔性的聚合物电解质硅一体化电极及其制备方法与应用

Also Published As

Publication number Publication date
TW202002365A (zh) 2020-01-01

Similar Documents

Publication Publication Date Title
US20210111400A1 (en) Cathodes for solid-state lithium sulfur batteries and methods of manufacturing thereof
WO2020005702A1 (fr) Cathodes pour batteries au lithium-soufre à l'état solide et leurs procédés de fabrication
KR20240051309A (ko) 고체 상태 하이브리드 전해질, 이의 제조 방법 및 이의 용도
Zeng et al. Green synthesis of a Se/HPCF–rGO composite for Li–Se batteries with excellent long-term cycling performance
US20200112050A1 (en) Solid-state hybrid electrolytes, methods of making same, and uses thereof
US11695118B2 (en) Modified cathodes for solid-state lithium sulfur batteries and methods of manufacturing thereof
EP2201628B1 (fr) Séparateur pour pile électrochimique et procédé pour sa fabrication
US7361431B2 (en) Cathode electrode including a porous conductive material coated and/or filled with sulfur and/or a sulfur-containing organic compound and lithium battery containing the same
Wang et al. Highly reversible lithium storage in Si (core)–hollow carbon nanofibers (sheath) nanocomposites
CA3004938A1 (fr) Composites de carbone
Liao et al. Novel flower-like hierarchical carbon sphere with multi-scale pores coated on PP separator for high-performance lithium-sulfur batteries
KR20140140323A (ko) 리튬 이차 전지용 음극 활물질, 이의 제조 방법 및 이를 포함하는 리튬 이차전지
KR20150138267A (ko) 고체 상태 전해질 물질을 가진 이온-전도 배터리
US20220181628A1 (en) Modified cathodes for solid-state lithium sulfur batteries and methods of manufacturing thereof
Bu et al. Co-spray printing of LiFePO 4 and PEO-Li 1.5 Al 0.5 Ge 1.5 (PO 4) 3 hybrid electrodes for all-solid-state Li-ion battery applications
US11217826B2 (en) Methods of making sulfide-impregnated solid-state battery
KR101876059B1 (ko) 듀플렉스 고체전해질막의 제조방법, 이에 의해 제조된 듀플렉스 고체전해질막 및 이를 이용한 전고체전지의 제조방법
Park et al. Coaxial carbon nanofiber/NiO core–shell nanocables as anodes for lithium ion batteries
Shafique et al. The impact of polymeric binder on the morphology and performances of sulfur electrodes in lithium–sulfur batteries
KR101553957B1 (ko) 리튬 이차 전지용 전극 활물질의 제조 방법, 리튬 이차 전지용 전극 활물질, 및 리튬 이차 전지
KR20230004824A (ko) 다공성 전극을 제조하기 위한 방법 및 그러한 전극을 포함하는 배터리
Angulakshmi et al. An efficient bi-functional permselective separator coated with cubic type-Li 7 La 3 Zr 2 O 12 and activated carbon for lithium–sulfur batteries
Dubey et al. Fabrication of ultra-thin, flexible, dendrite-free, robust and nanostructured solid electrolyte membranes for solid-state Li-batteries
KR20180072108A (ko) 기공 네트를 포함하는 탄소나노섬유 및 그의 제조방법
WO2023108106A1 (fr) Matériaux composites assurant une performance de batterie améliorée et leurs procédés de fabrication

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: 19740126

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: 19740126

Country of ref document: EP

Kind code of ref document: A1