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
  • H01M4/13—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
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  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B17/00—Sulfur; Compounds thereof
  • C01B17/22—Alkali metal sulfides or polysulfides
  • C01B17/24—Preparation by reduction
  • C01B17/28—Preparation by reduction with reducing gases
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  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B32/00—Carbon; Compounds thereof
  • C01B32/05—Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30
• • H—ELECTRICITY
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  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/05—Accumulators with non-aqueous electrolyte
  • H01M10/052—Li-accumulators
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/05—Accumulators with non-aqueous electrolyte
  • H01M10/052—Li-accumulators
  • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • 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
• • 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
  • H01M4/1393—Processes of manufacture of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• • 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
  • H01M4/362—Composites
  • H01M4/366—Composites as layered products
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/36—Selection of substances as active materials, active masses, active liquids
  • H01M4/58—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
  • H01M4/58—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
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2004/00—Particle morphology
  • C01P2004/80—Particles consisting of a mixture of two or more inorganic phases
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2006/00—Physical properties of inorganic compounds
  • C01P2006/40—Electric properties
• • H—ELECTRICITY
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  • 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

Definitions

• This invention relates to materials for battery electrodes, and in particular to materials for battery electrodes containing lithium sulfide and methods thereof. In one example, this invention is related to lithium-sulfide carbon composites.
• the invention of rechargeable lithium-ion (Li-ion) battery technology has set the standard in energy storage over the last several decades for powering portable phones, computers, and electric vehicles. While the demand for devices that provide faster data communication, increased computational power, brighter and higher resolution displays, and batteries with longer ranges, better performances, shorter charging times, at reduced weight and lower cost has increased over that time, the capability and development of lithium-ion batteries has not kept pace with this increase in demand.
• Li-S lithium-sulfur
• Most Li-ion batteries have energy capacity in the range of 150 to 250 Wh/kg, while Li-S batteries may offer energy capacity of 400+ Wh/kg. Therefore, Li-S batteries can have higher cell-level (and pack-level) capacity than current Li-ion batteries.
• Lithium metal anode can be prone to dendrite growth that can cause thermal runaway due to internal short circuit of the battery.
• using lithium anode, and in particular to Li-S batteries can lead to undesirable side reactions as the polysulfide diffuses back and forth between the electrodes in a phenomenon known as the shuttle mechanism, which reduces the charge-discharge efficiency and cycle stability due to lithium corrosion and sulfur oxidation.
• using lithium metal is not cost-effective, since commercial lithium anodes (typically Li thin foils) require sophisticated processes (purification, extrusion, passivation, etc.) because lithium is very active towards moisture and air (oxygen and nitrogen).
• the present disclosure provides a solution to these problems by using a continuous and scalable aerosol spray pyrolysis (ASP) process to form lithium-sulfide-carbon composites, which can be a superior cathode material as compared to sulfur because the resulting structure of the material mitigates capacity fading due to the loss of active sulfur material.
• ASP aerosol spray pyrolysis
• non-lithium high-capacity anode materials such as tin based materials and silicon based materials can be used in the lithium sulfur cell. Therefore, using the lithium-sulfide cathode material as described herein can also minimize or prevent the aforementioned disadvantages associated with the use of lithium metal anode.
• lithium sulfide has been synthesized by ball-milling lithium sulfide and carbon as well as lithiation of conventional sulfur cathode materials.
• the lithium-sulfide cathode material of the present disclosure can provide a superior material for use in a battery (e.g., Li-ion, Li-S, etc.) as compared to the previous approaches.
• the ASP process allows the lithium sulfide to be more uniformly dispersed within the carbon matrix, the kinetics of charge transfer process can be improved to result in improved rate capability (the capacity to be discharged and charged at a faster rate).
• the uniform lithium sulfide dispersion in the carbon matrix can also effectively sequestrate the dissolution of lithium polysulfides thus alleviating the shuttle mechanism.
• Example 1 can include subject matter (such as a method) for forming a battery electrode.
• the method can include forming a precursor solution including a lithium sulfide precursor and a carbon precursor; converting the precursor solution into an aerosol; removing water from the aerosol to form precursor particles; reacting the precursor particles at a first reaction temperature to form lithium carbonate; and reacting the lithium carbonate with hydrogen sulfide to form a lithium-sulfide-carbon composite.
• Example 2 the subject matter of Example 1 can optionally be configured to include shaping an amount of the lithium-sulfide-carbon composite into an electrode.
• Example 3 the subject matter of any one or any combination of Examples 1 or 2 can optionally be configured to include where the lithium sulfide precursor is selected from lithium nitrate, lithium acetate, and lithium carbonate.
• Example 4 the subject matter of any one or any combination of Examples 1 through 3 can optionally be configured where the carbon precursor is selected from sucrose, glucose, and polyvinylpyrrolidone.
• Example 5 the subject matter of any one or any combination of Examples 1 through 4 can optionally be configured where the lithium sulfide precursor is lithium nitrate and the carbon precursor is sucrose.
• Example 6 the subject matter of any one or any combination of Examples 1 through 5 can optionally be configured where the lithium sulfide precursor is lithium acetate and the carbon precursor is sucrose.
• Example 7 the subject matter of any one or any combination of Examples 1 through 6 can optionally be configured where the lithium sulfide precursor is lithium acetate and the carbon precursor is sucrose.
• Example 8 the subject matter of any one or any combination of Examples 1 through 7 can optionally be configured where the
• lithium-sulfide-carbon composite includes about 50 volume percent to about 65 volume percent of lithium sulfide.
• Example 9 the subject matter of any one or any combination of Examples 1 through 8 can optionally be configured where the precursor particles have a water content of less than 20 percent.
• Example 10 the subject matter of any one or any combination of Examples 1 through 9 can optionally be configured where reacting the lithium carbonate with hydrogen sulfide includes reacting the lithium carbonate with hydrogen sulfide at a second temperature in a gaseous environment including an inert gas an hydrogen sulfide, wherein the second temperature less than the first temperature.
• Example 11 the subject matter of any one or any combination of Examples 1 through 10 can optionally be configured to include forming the gaseous environment.
• Example 12 the subject matter of any one or any combination of Examples 1 through 11 can optionally be configured where forming the gaseous environment including flowing argon and hydrogen over elemental sulfur.
• Example 13 can include subject matter (such as a method) for forming a battery.
• the method can include obtaining or providing a first electrode, including: a lithium-sulfide-carbon composite formed by an aerosol spray pyrolysis process, wherein a plurality of lithium-sulfide particles are at least 70 weight percent of the electrode; obtaining or providing a second non-lithium containing electrode; and contacting an electrolyte with both the first electrode and the second non-lithium containing electrode.
• Example 14 the subject matter of any one or any combination of Examples 1 through 13 can optionally be configured to include forming the first electrode, including: forming a precursor solution including a lithium sulfide precursor and a carbon precursor; converting the precursor solution into an aerosol; removing water from the aerosol to form precursor particles; reacting the precursor particles at a first reaction temperature to form lithium carbonate; and reacting the lithium carbonate with hydrogen sulfide to form a
• Example 15 the subject matter of any one or any combination of Examples 1 through 14 can optionally be configured where the lithium sulfide precursor is selected from lithium nitrate, lithium acetate, and lithium carbonate and the carbon precursor is selected from sucrose, glucose, and
• Example 16 the subject matter of any one or any combination of Examples 1 through 15 can optionally be configured where the second electrode includes at least one of tin and silicone.
• Example 17 the subject matter of any one or any combination of Examples 1 through 16 can optionally be configured where the battery is a CR2032 form factor.
• Example 18 can include an electrode including a carbon matrix; and a plurality of lithium-sulfide particles uniformly distributed into the carbon matrix, wherein the plurality of lithium-sulfide particles are about 70 weight percent of the electrode.
• Example 19 the subject matter of any one or any combination of Examples 1 through 18 can optionally be configured where the plurality of lithium particles are uniformly distributed into the carbon matrix via an aerosol spray pyrolysis process such that per one gram of carbon includes lithium-sulfide particles within the range of about 1 gram to about 2.5 grams.
• Example 20 can include a battery.
• the battery includes a first electrode, including a plurality of lithium-sulfide particles coated with a carbon shell, a second electrode, and an electrolyte in contact with both the first electrode and the second electrode.
• Example 21 can include the battery of example 20, wherein the plurality of lithium-sulfide particles coated with a carbon shell include a plurality of lithium-sulfide particles coated with an amorphous carbon shell.
• Example 22 can include the battery of any one of examples 20-21, wherein the plurality of lithium-sulfide particles are about 70 weight percent of the electrode.
• Example 23 can include the battery of any one of examples 20-22, wherein the plurality of lithium particles are uniformly distributed via an aerosol spray pyrolysis process such that per one gram of carbon includes lithium-sulfide particles within the range of about 1 gram to about 2.5 grams.
• FIG. 1 shows a diagram of an aerosol spray pyrolysis (ASP) process according to one example of the present disclosure.
• FIG. 2 shows a diagram of an ASP process according to one example of the present disclosure.
• FIG. 3 shows a diagram of an ASP process according to two types of precipitations
• FIG. 4 shows an illustration of the lithium-sulfide-carbon composite according to one example of the present disclosure.
• FIG. 5A shows a transmission electron microscopy (TEM) image of the lithium-sulfide-carbon composite according to one example of the present disclosure.
• FIG. 5B shows a TEM image of the lithium-sulfide-carbon composite according to one example of the present disclosure.
• FIG. 5C shows a TEM image of the lithium-sulfide-carbon composite according to one example of the present disclosure.
• FIG. 6A shows electrical performance data of batteries using particles according to one example of the present disclosure.
• FIG. 6B shows additional electrical performance data of batteries using particles according to one example of the present disclosure.
• FIG. 7 shows a battery according to one example of the present disclosure.
• FIG. 8 shows a method of forming an electrode according to one example of the present disclosure.
• FIG. 9 shows a method of forming a battery according to one example of the present disclosure.
• FIG. 10 shows components of a an aerosol spray pyrolysis (ASP) system according to one example of the present disclosure.
• FIG. 11 shows a diagram of an ASP process according to one example of the present disclosure.
• FIG. 12 shows x-ray diffraction data of materials formed according to one example of the present disclosure.
• FIG. 13 shows carbon content of materials formed according to one example of the present disclosure.
• FIG. 14 shows images of materials formed according to one example of the present disclosure.
• FIG. 15 shows x-ray diffraction data of materials formed according to one example of the present disclosure.
• FIG. 16 shows graphs of electrical properties of electrodes according to one example of the present disclosure.
• Lithium-sulfide-carbon (L12S-C) composites are shown fabricated via an aerosol spray pyrolysis (ASP) process.
• the ASP process provides the L12S-C composite material with rationally designed structures and desirable functionality.
• FIGS. 1 and 2 show diagrams illustrating an example of the ASP process.
• the ASP process as shown in FIG. 1 is a continuous process/setup composed of four major components including: (1) an atomizer, (2) a diffusion dryer, (3) a tubular reactor for thermolysis reactions, and (4) a reactor for post-treatments.
• the ASP process can start with atomization of a homogenous solution of precursors through the atomizer.
• the precursors i.e. the reactants to synthesize the L12S-C composites, can include carbon precursors and L12S precursors.
• Three examples of lithium salts including lithium nitrate (L1NO3), lithium carbonate (L12CO3), and lithium acetate (CH3COOL1) are used as the L12S precursors.
• the carbon precursors can be selected from sucrose, glucose, starch, and polyvinylpyrrolidone.
• the atomizer can generate an aerosol of the precursor solution.
• aerosol or "aerosol droplets” are defined as a colloidal suspension of particles dispersed in a gas.
• the generated aerosol (small droplets of the precursor solution) from the atomizer is carried by inert gas through the diffusion dryer to remove the water content.
• inert gas In one example, argon is used as the inert gas. However, other inert gases can be used as well.
• the bulk solution of the precursor solution can go through atomizer such that an aerosol of the precursor solution is formed.
• the aerosol can go through the diffusion dryer.
• the diffusion dryer can include silica gel as an absorbing agent and can operate at, for example, 700 degrees Celsius (°C). However, other absorbing agents can be used and the diffusion dryer can operate at other temperatures. In an example, the diffusion dryer can remove water within a range of about 60 percent (%) to about 80%.
• FIG. 3 shows a diagram of an ASP process according to two types of precipitations.
• the solutes e.g., reactants Li salts and sucrose
• volume precipitation can occur, i.e. the reactants (Li salts and sucrose) precipitate simultaneously and homogeneously to result in homogeneous mixture.
• the subsequent thermal reaction can enable Li salts decomposition and carbonization to result in a homogeneous structure with uniform dispersion and carbon encapsulation.
• the resulting solid precursor particles are sequentially carried into the tubular furnace reactor (hereinafter "tubular reactor"), in which a variety of reactions are thermally induced.
• tubular reactor tubular furnace reactor
• the uniqueness of the ASP process is that the precursors are mixed very uniformly in the small particles, which can be considered individual micro-reactors.
• the small particle size of the particles e.g., tens to hundreds of nanometers
• desired microstructures can be achieved by manipulating the precursor compositions and the ASP processing parameters.
• the precursor solution can include the precursors LiNC and sucrose, CH3COOL1 and sucrose, or L12CO3 and sucrose.
• the precursor solution can include 0.15 M L1NO3 and 0.15 M sucrose, 0.15 M CH3COOL1 and 0.15 M sucrose, or 0.075 M L12CO3 and 0.15 M sucrose in water, respectively.
• the L1NO3 precursor can have a concentration within a range of from about 0.1 M to about 1M, for example, 0.1 M to 0.5 M such as 0.1 M to 0.2 M and the sucrose precursor can have a concentration within a range of about 0.1 M to about 1 M, for example, 0.1 M to 0.5 M such as 0.1 M to 0.2 M.
• the CH3COOLi concentration can be within a range from about 0.1 M to about 1M, for example, 0.1 M to 0.5 M such as 0.1 M to 0.2 M and the sucrose concentration can be within a range from about 0.05 M to about 0.4 M, for example, 0.05 M to 0.25 M such as 0.05 M to 0 15 M.
• the L12CO3 concentration can be within a range from about 0.02 M to about 0.15 M, for example, 0.02 M to 0.1 M such as 0.02 M to 0.05 M and the sucrose concentration can be within a range from about 0.05 M to about 0.3 M, for example, 0.05 M to 0.2 M such as 0.05 M to 0.15 M.
• the lithium nitrate can form lithium oxide, nitrogen dioxide, and oxygen and the sucrose can form carbon.
• the lithium oxide, carbon, and oxygen can react to form lithium carbonate-carbon (L12CO3-C) composite, which is the reactor product leaving the tubular reactor.
• the precursors can be completely consumed during the reactions.
• L12O lithium carbonate-carbon
• the output of L12CO3 can be greater than 85% and the existence of the residual L12O will not impair the final product of L12S since the subsequent H2S treatment can also convert L12O to L12S via the following reaction:
• the reaction temperature can be within a range from about 600 °C to about 1000 °C. In one example, the reaction temperature is about 700 °C.
• the reactor product, the L12CO3-C composite can be collected and sent to a post-treatment reactor to form the final product, the lithium-sulfide-carbon composite.
• the post post-treatment furnace can be connected directly to the tubular reactor or separated as an individual reactor. In the former, the Li2C03-C can be collected directly in the post-treatment reactor and in the later, the Li2C03-C can be collected with a filter collector, and then sent to the post-treatment reactor.
• the reactor product can further be heated at a post-treatment temperature in a gaseous environment.
• the post-treatment temperature can be within a range of about 500 °C to about 700 °C. In one example, the post-treatment temperature is 550°C.
• the gaseous environment can be composed of an inert gas (e.g., argon) and hydrogen sulfide (H2S).
• the gaseous environment includes about 99 volume percent (vol. %) to about 95 vol. % of argon and about 1 vol. % to about 5 vol. % of H2S.
• the gaseous environment includes about 95 vol. % argon and 5 vol. % H2S.
• Such an environment can be generated by flowing 95 vol. % and 5 vol. % H2 over elemental sulfur.
• the following reaction of the L12CO3-C composite occurs with H2S:
• the final product from Reaction 5 can be a L12S-C composite.
• Li2C0 3 and sucrose are used as the precursors, Li2C0 3 does not decompose in the reactor, but serves as the catalyst for carbonization from sucrose.
• the L12S-C is then produced according to reaction [5].
• the L12S-C composite can have a lithium sulfide content of about 70 weight percent (wt.%) to about 80 wt.%.
• the synthesized L12S-C composite can have the lithium sulfide more evenly and uniformly dispersed. That is, more of the lithium sulfide can be incorporated into the carbon matrix and increase electrical properties.
• FIG. 4 illustrates a diagram of the L12S-C composite and illustrates that the present disclosure can provide a L12S-C composite where the lithium sulfide can be more uniformly and evenly dispersed within the carbon matrix.
• L12S-C composites using L1NO3, L12CO3, and CEbCOOLi and sucrose were formed.
• the precursor solution was sent to the atomizer of the ASP process to form an aerosol.
• the aerosol was sent to the diffusion dryer (25 °C) to remove the water content and form precursor particles.
• the precursor particles were sent to the tubular reactor (700 °C) and the lithium carbonate-carbon (L12CO3-C) composite (reactor product) was formed.
• the reactor product, the L12CO3-C was collected and sent to a post-treatment reactor.
• the reactor product was heated to 550 °C in a gaseous environment including 95 vol. % argon and 5 vol. % H2S to form the final product (L12S-C composite).
• lOOg of 0.3 M CH3COOL1 and lOOg of 0.3 M sucrose were mixed together to form the precursor solution.
• the precursor solution was sent to the atomizer of the ASP process to form an aerosol.
• the aerosol was sent to the diffusion dryer (25 °C) to remove the water content and form precursor particles.
• the precursor particles were sent to the tubular reactor (700 °C) and the lithium carbonate-carbon (L12CO3-C) composite (reactor product) was formed.
• the reactor product, the L12CO3-C was collected and sent to a post-treatment reactor.
• the reactor product was heated to 550 °C in a gaseous environment including 95 vol. % argon and 5 vol. % H2S to form the final product (L12S-C composite).
• lOOg of 0.15 M L12CO3 and lOOg of 0.3 M sucrose were mixed together to form the precursor solution.
• the precursor solution was sent to the atomizer of the ASP process to form an aerosol.
• the aerosol was sent to the diffusion dryer (25 °C) to remove the water content and form precursor particles.
• the precursor particles were sent to the tubular reactor (700 °C) and the lithium carbonate-carbon (L12CO3-C) composite (reactor product) was formed.
• the reactor product, the L12CO3-C was collected and sent to a post-treatment reactor.
• the reactor product was heated to 550 °C in a gaseous environment including 95 vol. % argon and 5 vol. % H2S to form the final product (L12S-C composite).
• FIGS. 5A, 5B, and 5C The transmission electron microscopy (TEM) images of the L12S-C composite particles formed from L1NO3, L12CO3, and CH3COOL1 are shown in FIGS. 5A, 5B, and 5C, respectively.
• the L12S-C composite particles formed from L1NO3, as shown in FIG. 5A have a porous structure indicated by the contrast as the lighter spots are pores.
• the porosity is induced by the gas (NO2 and O2) formation and carbon consumption.
• the Li2S-C composite particles formed from L12CO3 (shown in FIG. 5B) and CH3COOL1 (shown in FIG. 5C) have a homogeneous structure, since there is less or no gas generation.
• the performance advantages provided by using the L12S-C composite of the present disclosure can include minimization, avoidance and prevention of the capacity fading due to irreversible active material loss, dendrite growth and thermal runaway due to internal short circuit, the shuttle mechanism, as well as improvement in charge-discharge efficiency, cycle stability and enabling higher capacity of energy storage at lower material and processing cost.
• lithium sulfide can be evenly and uniformly dispersed within the carbon matrix, which can improve the utilization of the active material and mitigate lithium polysulfide dissolution.
• the Li2S-C composite particles formed from CH3COOLi can have 75 wt. % of L12S (FIG. 5C).
• the TEM image has very uniform structure indicating the L12S is very uniformly dispersed in the carbon matrix.
• FIGS. 6 A and 6B The electrical performance of a sample of the L12S-C composite formed from using LiNCb/sucrose precursors is shown in FIGS. 6 A and 6B.
• the L12S-C composite was mixed with carbon black powder (conductive additive) and polyvinylidene fluoride (polymer binder) in N-methyl-2-pyrrolidone to form the electrode slurry.
• the weight percentages of L12S-C, carbon black, and polyvinylidene fluoride are 70%, 20% and 10%, respectively.
• the slurry was coated on an aluminum foil using a blade coater. The electrode was dried at room temperature for 24 hours followed by drying in a vacuum oven at 60 °C for overnight.
• a half cell with Li metal as the counter electrode was made in CR2032-type coin cells.
• CR2032-type coin cells were then fabricated with the L12S-C composite as the working electrode, microporous polypropylene as the separator (Celgard 2300), and Li metal foil as the counter electrode.
• the electrolyte used was 1 M lithium
• FIG. 6A is the galvanostatic charge-discharge curve of the first two cycles of the Li2S-C composite.
• the first charge undergoes an activation process indicated by the overshot of the potential at 3.25 V and the higher plateau at 2.6 V.
• the L12S-C composite demonstrates typical Li-S reaction mechanisms.
• FIG. 6B illustrates the cycle stability.
• the L12S-C composite can retain a capacity of > 600 mAh/g after 35 cycles with a current density of 56 mA/g (1/20 C).
• the present disclosure provides a method that is distinctly different from all existing methods to produce L12S-C cathode materials for Li-S batteries
• the present disclosure provides a novel method using aerosol assisted spray pyrolysis process to synthesize L12S-C composites.
• FIG. 7 shows an example of a battery 700 according to an embodiment of the invention.
• the battery 700 is shown including an anode 710 and a cathode 712.
• An electrolyte 714 is shown between the anode 710 and the cathode 712.
• the battery 700 is a lithium-ion or lithium-sulfur battery.
• the cathode 712 can be the L12S-C composite as described in examples above and the anode 710 can be a non-lithium high-capacity anode material selected from tin and silicon based materials.
• Figure 8 shows an example method of forming an electrode according to an embodiment of the invention.
• operation 802 includes forming a precursor solution including a lithium sulfide precursor and a carbon precursor.
• operation 804 includes converting the precursor solution into an aerosol.
• operation 806 includes removing water from the aerosol to form precursor particles.
• operation 808 includes reacting the precursor particles at a first reaction temperature to form lithium carbonate.
• operation 810 includes reacting the lithium carbonate with hydrogen sulfide to form a
• FIG. 9 shows an example method of forming a battery according to an embodiment of the invention.
• operation 902 includes obtaining or providing a first electrode, including a lithium-sulfide-carbon composite formed by an aerosol spray pyrolysis process, wherein a plurality of lithium-sulfide particles are at least 70 weight percent of the electrode.
• operation 904 includes obtaining or providing a second non-lithium containing electrode.
• operation 906 includes contacting an electrolyte with both the first electrode and the second non-lithium containing electrode.
• the lithium-sulfur (Li-S) battery has garnered increasing interest in recent years as a low cost, environmentally benign energy storage solution.
• Li-S Owing to its high theoretical capacity and low cost of materials, Li-S is well suited to a broad range of applications from smart grid system to electric vehicles. Though the Li-S chemistry is not new, scalable production of reliably performing batteries has eluded manufacturing efforts.
• a critical challenge of the Li-S cell is the solid-liquid-solid transition experienced by the sulfur during discharge/charge. While S8 (fully charged cathode) and L12S (fully discharged cathode) are insoluble in the electrolyte, the intermediate species, known as polysulfides, are soluble in organic electrolytes. The soluble species migrate through the electrolyte, eventually contacting the anode, where they reduce by reaction with available anode lithium in a process called the Polysulfide Shuttle.
• Typical designs involve carbon rods as a sulfur deposition surface, high surface amorphous particles, nanotube mats or chemically linked carbon backbones.
• These techniques offered better electrical conductivity and greater utilization of sulfur, but nonetheless suffered severe capacity degradation, as they failed to account for dissolution losses. Later attempts focused on means of entrapping either the soluble or insoluble phases; these included reducing solubility by limiting the size of the sulfur species in tight channels, using polar functional groups to maintain an attraction to polysulfides and polymer coating of sulfur. While these techniques offer improvements in cycle stability and rate performance due to conductivity enhancements, they failed to deliver on the promise of a long cycle life. By producing a sulfur cathode, processing was limited by the melting point of sulfur and as such, only relatively low temperature techniques were accessible.
• L12S based cathodes have included: simple mixing of L12S with rubber, solution based layering of L12S and carbon, followed by CVD, injection into an electrolyte system separated from the anode, reduction of L12SO4 by graphene aggregates, reduced graphene oxide graphitization with L12S6, polymerization of pyrrole around L12S particles, carbonization of pyrrole around a Li2S/carbon-black ball milled mix, reaction of L12S with TiCU to form a protective T1S2 shell, spreading of L12S powder into a CNT mat, agglomeration of dissolved L12S onto MWCNTs.
• Common to the techniques cited are the use of expensive materials or process steps. While tailoring the cathode to the lithiated state has shown improvements in terms of cycle stability and sulfur utilization, the processes discussed remain unreasonable for scale-up. As such, the ideal production method would leverage simpler starting materials and avoid expensive reaction steps.
• ASP Aerosol Spray Pyrolysis
• Lithium carbonate is formed with one of the following precursors: lithium acetate (CH3COOL1), lithium nitrate (L1NO3) or lithium carbonate, all of which yield L12CO3 under identical reaction conditions.
• CH3COOL1 lithium acetate
• L1NO3 lithium nitrate
• Li carbonate all of which yield L12CO3 under identical reaction conditions.
• polyvinylpyrrolidone PVP, MW 55,000
• PVP polyvinylpyrrolidone
• the Li2C03@C composite is post-treated to yield a Li2S@C composite using mixed hydrogen sulfide/argon gas (FhS/Ar at 5/95 vol.%) at elevated temperature.
• FhS/Ar mixed hydrogen sulfide/argon gas
• the precursor solution (listed in Table 1) is thoroughly mixed via stir plate until no precipitates are visible, then loaded into the nebulizer reservoir bottle
• the nebulizer (TSI, Model 3076) is attached to the bottom of a diffusion dryer, then connected to the precursor solution reservoir.
• the diffusion dryer is composed of two concentric tubes: The outer tube is made of solid PVC tubing and the inner tube is made of 1 ⁇ 2" diameter steel mesh (Specialty Metals Inc.).
• the annular space is filled with porous silica gel to desiccate the water content from the aerosol of the precursor solution, as it passes through the diffusion dryer in an argon carrier stream.
• the resultant dried particles are carried through a quartz tube (1/2" OD, GM & Associates) through a tube furnace (61 cm heated length, Thermo-Scientific) connected to the diffusion dryer, in which Li2C03@C formation occurs at 850°C.
• a steel mesh filter (304SS, 325*2300 mesh, McMaster Carr) is attached to the end of the quartz tube via ultra-torr fittings (Swagelok).
• a lithium salt and a carbon precursor are added to 240ml of Ultra-Pure deionized water (Millipore), in concentrations articulated in the table below.
• the pyrolysis environment drives a carbonization of the carbon precursor, as aided by the salt nucleates. Without an appropriate nucleate the carbon precursor decomposes entirely. Exposure to a pyrolysis environment yields crystalline LiiCCb from all three initial salts, as is discussed in the Characterization section. Amorphous carbon is generated by the
• Figure 11 illustrates the evolution of aerosol droplet, from bulk solution to Li2C03@C composite particle.
• FIG. 1 Aerosol particle evolution.
• Bulk solution in the reservoir is aspirated into the nebulizer, where it is aerosolized by the argon carrier gas feed. Drying begins in the diffusion dryer and completes in the heated zone. Lithium salt and carbon precursor carbonization proceed in the heated zone. Li 2 C03@C composite particle is then collected on a mesh filter.
• L12CO3 with no evidence of either L1NO3 or L12O. Suggesting a source of CO2, such as the oxidation of carbon by the evolved oxygen,
• Mass loading of carbon within the composite is measured via thermogravimetric analysis with a Q500 TGA (TA Instruments Inc). Samples are held at a 120°C plateau to remove the moisture absorbed from environment. The sample is then ramped to 600°C at 10°C per minute. 600°C is held for an hour. At this point the carbon content has oxidized, and the remaining mass can be taken as L12CO3. All compositions were standardized to a range of 20-25% carbon content in the pyrolysis material as shown in Figure 13, so as to eliminate carbon content as a significant variable in cell performance. As shown in Figure 13, TGA analysis of carbon content. A narrow range of 20-25% carbon was selected to reflect a realistic compromise for all six compounds, and offer a robust comparison, where carbon loading in and of itself is not a variable. A fully optimized composite is likely to require less carbon
• Figure 14 articulates the varying architectures achieved by different precursor sets, at similar carbon loadings.
• Figure 14 shows, from top left, Li2C03@C particles of the following compositions: AceS, AceP, CarS, CarP, NitS, NitP.
• Li 2 S@C composite is mixed with 3.33 wt.% Polystyrene solution in Mesitylene (Sigma Aldrich) and conductive carbon (C65, Timcal) additive in a 70/20/10 mass ratio (Li 2 S@C/conductive carbon/polystyrene).
• the resulting paste is spread on a carbon coated aluminum foil (MTI) current collector.
• the cathode foil is dried overnight in an argon filled glovebox at room temperature, punched with a 1 ⁇ 2" hole punch then held at 120°C for four hours, in argon, to ensure that the electrodes are solvent free.
• the dried electrodes are assembled into a 2032 coin cell.
• the anode is a lithium foil (99.9%, Alfa Aesar)
• the separator is a porous polypropylene membrane (MTI XTL Inc.)
• the electrolyte is a 1M LiTFSI solution of 1 : 1 :2 by vol. mixture of dioxolane (Sigma Aldrich), dimethyl ether (Sigma Aldrich) and 1 -Butyl- 1-methylpyrrolidinium
• LiNCb bis(trifluoromethanesulfonyl)imide with 1.5 wt.% LiNCb (Sigma Aldrich). Battery cycling was done in a battery cycler (Arbin). The first cycle is run at a rate of C/50 (23.3 mA/g based on Li 2 S) to a cutoff of 3.5V to 1.8V. Subsequent cycles are run at C/10 between 2 6V and 1.8V.
• Figure 16 shows the capacity of Li 2 S@C from precursors of NitS, AceS and CarS, denoted as Li 2 S@C ts, Li 2 S@CAceS and Li 2 S@Ccars, respectively.
• substantially instantaneously refers to events occurring at approximately the same time. It is contemplated by the inventor that response times can be limited by mechanical, electrical, or chemical processes and systems Substantially simultaneously, substantially immediately, or substantially instantaneously can include time periods 1 minute or less, 45 seconds or less, 30 seconds or less, 20 seconds or less, 15 seconds or less, 10 seconds or less, 5 seconds or less, 3 seconds or less, 2 seconds or less, 1 second or less, 0.5 seconds or less, or 0 1 seconds or less.

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