KR20140000213A - In-situ synthesis and deposition of battery active lithium materials by spraying - Google Patents

Abstract

Methods and apparatus are provided for forming an electrochemical layer of a thin film battery. A liquid precursor mixture comprising electrochemically active metals reacts with oxygen to form electrochemically active metal oxides, which are deposited in layers on the substrate. Carbon can be added to the mixture to control the energy input into the reaction and provide conductivity and adhesion between the crystals deposited on the substrate. Conversion of precursors into deposition crystals may be achieved in a two-stage process.
An apparatus for forming an electrochemical layer on a substrate is provided. Such an apparatus has a first processing stage having a liquid precursor source, an atomizing gas source, and a dry energy source coupled to the first distributor. The collection stage near the first distributor has solids receptors. The second processing stage has a second distributor near the collection stage and a source of activation energy coupled to the second distributor.

Description

INSITU SYNTHESIS AND DEPOSITION OF BATTERY ACTIVE LITHIUM MATERIALS BY SPRAYING

The present invention relates generally to lithium-ion batteries and, more particularly, to a method for manufacturing such batteries using thin-film deposition processes.

Fast-filling, high capacity energy storage devices, such as supercapacitors and lithium (Li) ion batteries, are being used in ever-increasing applications, such applications being portable electronics, medical devices. , Transportation, grid-connected large energy storage, renewable energy storage, and an uninterruptible supply (UPS). In modern rechargeable energy storage devices, current collectors are made of electrical conductors. Examples of materials for the positive current collector (cathode) include aluminum, stainless steel, and nickel. Examples of materials for the negative current collector (anode) include copper (Cu), stainless steel, and nickel (Ni). Such collectors may be in the form of foils, films, or thin plates having a thickness range of generally about 6-50 μm.

Typical lithium ion batteries are filled with an electrolyte liquid consisting of lithium salts such as LiPF ₆ , LiBF ₄ , or LiClO _{4 in an} organic solvent such as ethylene carbonate, or complexed with lithium salts and / or filled with liquid electrolytes. Consisting of a carbon anode separated by a solid polymer electrolyte, such as polyethylene oxide, and a lithium metal oxide or phosphate cathode. The negative electrode material is typically selected from lithium transition metal oxides such as LiMn ₂ O ₄ , LiCoO _{2 ,} LiNiO ₂ , or combinations of Ni, Li, Mn, and Co oxides, and such as carbon or graphite Electroconductive particles, and a binder material. The negative electrode material is considered to be a lithium-intercalation compound, where the amount of conductive material is in the range of about 0.1% to about 15% by weight. The negative electrode material may be applied as a paste to a conductive sheet electrode and consolidated between hot rollers, or sprayed as a solution or slurry, and the resulting substrate may be dried to remove the liquid carrier.

Graphite may be in the form of lithium-intercalated MCMB powder, which is frequently used as a cathode material and consists of meso-carbon micro beads (MCMBs) having a diameter of about 10 μm. Lithium-intercalation MCMB powder is dispersed in a polymeric binder matrix. Polymers for the binder substrate are made of thermoplastic polymers, including polymers having rubber elasticity. The polymeric binder serves to bond the MCMB material powders together to prevent crack formation and to prevent the MCMB powder from disintegrating on the surface of the current collector. The amount of polymeric binder ranges from about 0.5% to about 15% by weight. The polymer / MCMB mixture may be applied as a paste and consolidated between hot rolls, or may be applied with a liquid solution, and the resulting substrate may be dried to remove solvent.

Some Li-ion batteries use separators made from microporous polyolefin polymers, such as polyethylene foams, applied in separate manufacturing steps. In general, such a separator, as described above, will be filled with a liquid electrolyte to form the final battery.

As the use of thin film Li-ion batteries continues to grow, there is a continuing need for thin film Li-ion batteries that can be manufactured at smaller, lighter, and more efficient costs.

Embodiments disclosed herein provide an apparatus for forming an electrochemical layer on a substrate. Such an apparatus has a first processing stage having a liquid precursor source, an atomizing gas source, and a dry energy source coupled to the first distributor. The collection stage near the first distributor has solids receptors. The second processing stage has a second distributor near the collection stage and a source of activation energy coupled to the second distributor.

Some embodiments disclosed herein provide an apparatus for depositing an electrochemical layer on a substrate (hereinafter referred to as 'deposition' for convenience), which apparatus has a drying station, a collection station, and a synthesis station. The drying station includes a thermal spray (spray) nozzle having a liquid precursor source and an atomizing gas source coupled to the mixing site, an atomization opening that separates the mixing site from the drying site, and a chemical or thermal drying energy coupled to the drying site. A source and an output orifice near said drying location. The collection station has a cyclone separator and a hopper, and the tangential feed point of the cyclone separator is near the output orifice of the drying station. The solids output portion of the cyclone separator will be near the hopper, and a source of electrical energy may be coupled to the wall of the cyclone separator. The synthesis station has a plasma spray nozzle having an inlet coupled to the outlet of the hopper and to a plasma forming gas source, the source of power being coupled to the plasma spray nozzle. In some embodiments a flame spray nozzle may be used instead of the plasma spray nozzle. An additional nozzle is located at a defined distance from the outlet of the plasma spray nozzle.

Other embodiments include forming a precursor powder from a liquid precursor using a continuous drying process, forming an electrochemical precursor from the precursor powder by reacting the precursor powder with oxygen in a combustion process or plasma, forming an electrochemical precursor. A method of forming an electrochemical layer on a substrate by dispensing in a stream towards the substrate, adding a polymeric binder to the stream to form a deposition mixture, and depositing a deposition mixture on the substrate. It includes.

In a manner in which the above-cited features of the present invention may be specifically understood, with reference to the embodiments partially illustrated in the accompanying drawings, a more specific description of the invention briefly summarized above is made. It should be noted, however, that the present invention is recognized with respect to other equally effective embodiments, so that the accompanying drawings show only typical embodiments of the invention and are therefore not to be considered as limiting the scope of the invention. will be.
1 is a schematic diagram of a Li-ion battery according to one embodiment.
2 is a flow diagram summarizing a method according to one embodiment.
3 is a schematic cross-sectional view of a film forming apparatus according to an embodiment.
4 is a schematic cross-sectional view of a film forming apparatus according to another embodiment.
5A is a schematic plan view of a film forming apparatus according to another embodiment.
5B is a schematic cross-sectional view of a solid collection device for use in the device of FIG. 5A.
For ease of understanding, wherever possible, the same reference numerals have been used to denote like elements that are common in the figures. Without specific mention, it will be appreciated that elements disclosed in one embodiment may be advantageously used in other embodiments.

In general, the embodiments disclosed herein provide methods and apparatus for forming a film on a substrate. In one embodiment, the film may be a thin film battery, such as a Li-ion battery, or an electrochemical film for a supercapacitor device. An electrochemical precursor or mixture of electrochemical precursors is provided to the processing chamber, where energy is applied to cause the precursor or precursor mixture to become hot. The high temperature converts electrochemical precursors into electrochemically active nanocrystals, which form a layer or film on the substrate surface.

1 is a schematic diagram of a Li-ion battery 100 electrically connected to a load 101 in accordance with an embodiment of the present invention. The primary functional components of the Li-ion battery 100 include an electrolyte disposed in the region between the anode structure 102, the cathode structure 103, the separator layer 104, and the opposing current collectors 111 and 113. (Not shown) is included. Various materials may be used as the electrolyte, such as lithium salts in organic solvents or polymeric substrates, which may also be penetrated by organic solvents. An electrolyte is present in the anode structure 102, the cathode structure 103, and the separator layer 104 in the region formed between the current collectors 111 and 113.

Each of the positive electrode structure 102 and the negative electrode structure 103 serves as a half-cell of the Li-ion battery 100 and together form a complete working cell of the Li-ion battery 100. The anode structure 102 includes a current collector 111 and a first electrolyte containing material 110, such as a carbon-based intercalation host material for retaining lithium ions. Similarly, negative electrode structure 103 includes a current collector 113, and a second electrolyte containing material 112, such as a metal oxide, for retaining lithium ions. The current collectors 111 and 113 are made of an electrically conductive material such as metals. In some cases, separator layer 104, which may be a dielectric, porous, fluid permeable layer, is used to prevent direct electrical contact between components in anode structure 102 and cathode structure 103.

The electrochemically active material on the cathode side of the Li-ion battery 100, or on the positive electrode, comprises a lithium-containing metal oxide, such as lithium cobalt dioxide (LiCoO ₂ ) or lithium manganese dioxide (LiMnO ₂ ). You can do it. The electrolyte comprising the material is made of an oxide such as lithium cobalt oxide, an olivine such as lithium iron phosphate, or a spinel such as lithium manganese oxide (LiMn ₂ O ₄ ), formed in a layer on the positive electrode. Could be. In non-lithium embodiments, an exemplary cathode may be made of TiS ₂ (titanium disulfide). Exemplary lithium-containing oxides include lithium cobalt oxide, such as LiNi _x Co _{1 -xy} Mn _y O ₂ , for example LiMn ₂ O ₄ , which may have up to about 10% excess lithium above stoichiometric ratios, or It may be one or two or more layers of mixed metal oxide. Exemplary phosphates include iron olivine (LiFePO ₄ ) and its variants (eg [Li _x Fe _{1- x} ] _y MgPO ₄ ), LiMoPO ₄ , LiCoPO ₄ , Li ₃ V ₂ (PO ₄ ) ₃ , LiVOPO ₄ , LiMP ₂ O _7, or LiFe _{1 .5} P ₂ O ₇ Could be. Exemplary fluorophosphates include LiVPO ₄ F, LiAlPO ₄ F, Li ₅ V (PO ₄ ) ₂ F _2, Li ₅ Cr (PO ₄ ) ₂ F _2, Li ₂ CoPO ₄ F, or Li ₂ NiPO. Can be ₄ F. Exemplary silicates may be Li ₂ FeSiO ₄ , Li ₂ MnSiO ₄ , or Li ₂ VOSiO ₄ . An exemplary non-lithium compound is Na ₅ V ₂ (PO ₄ ) ₂ F ₃ .

An electrochemically active material on the anode side of the Li-ion battery 100, or on the negative electrode, may be made of the aforementioned materials, i.e. graphite based microbeads dispersed in a polymer matrix. Additionally, microbeads made of silicon, tin or lithium titanate (Li ₄ Ti ₅ O ₁₂ ) may be used with or instead of graphite-based microbeads to provide a conductive core anode material. will be.

Cathode materials as described above may be formed from liquid precursors in processes and apparatuses that separate drying operations and synthesis operations. 2 is a flow diagram summarizing a method 200 according to one embodiment. The method 200 is useful for forming a layer of electrochemical agent, such as the electrochemically active materials, cathode and / or anode materials described above. The substrate may have a surface that includes a conductive current collector for the battery structure as described above with respect to FIG. 1. For example, the substrate may have an aluminum electrode surface.

In step 202, a first precursor is provided to the first processing apparatus through a conduit. In one embodiment, the first processing apparatus may be a spraying apparatus or a dispenser. The first precursor may comprise one or two or more electrochemical precursors in solution. The solution may be an aqueous solution of metal salts or other metal solvents that may include miscible carbon-containing liquids such as alcohols. Carbon-containing solvents such as sugars may also be dissolved in solution. As will be described further below, carbon may be usefully added to an electrochemically active material in which carbon-containing liquids and solids are deposited on a substrate. The solution may be atomized by co-flowing with a gas such as argon, helium, nitrogen, air, oxygen, hydrogen, or mixtures thereof through a small opening in the first processing apparatus. For reasonable atomization, the solution will generally have a low viscosity, such as about 10 cP or less.

The first precursor may be an aqueous solution of metal nitrates (M _x (NO ₃ ) _y ), where x and y depend on the natural valence of the metal (M). The metal M may be lithium, manganese, nickel, cobalt, titanium, vanadium, iron, sodium, or chromium, and the first precursor may comprise a plurality of metals. Other salts such as organic salts of the metals may be used instead of, or in addition to, the nitrates. In one embodiment, one or more carboxylates, such as formate, acetate, tartarate, may be used.

By mixing standard solutions of the desired amounts of the individual metal salts, a precursor comprising a plurality of metal salts may be prepared. For example, 1M LiNO ₃ may be added to standard solutions of 1M Ni (NO ₃ ) ₂ , 1M Mn (NO ₃ ) ₂ , and / or 1M Co (NO ₃ ) ₂ or other metals. In some embodiments, excess lithium may be used to improve the performance of the deposited electrochemical layer, such as from about 1% excess to about 15% excess, for example about 10% excess. For example, 330 mL of 1 M LiNO ₃ is mixed with a 1 M solution of Ni (NO ₃ ) ₂ , Mn (NO ₃ ) ₂ , and Co (NO ₃ ) ₂ , each 100 mL to form an aqueous base stock; Constituents).

Carbon may be added by mixing in organic compounds, which may both be dissolved in water or mixed with water and may be solvents comprising oxygen and hydrogen, or sugars. Isopropyl alcohol, ethylene glycol, propylene glycol are examples of organic solvents that can be used. Sucrose is an exemplary sugar. Other solvents available are oxalyldihydrazine (a.k.a. oxalic acid hydrazide), and urea. The precursor mixture may be from about 80% to about 100% by weight of the aqueous base stock, from about 0% to about 17% of the organic solvent, and from about 0% to about 5% by weight. Exemplary electrochemical precursors include 85% aqueous base stock, 10% isopropyl alcohol, and 5% sugars.

In step 204, energy is applied to the first precursor in the first processing device to form a powdered electrochemical precursor that may include microcrystals of electrochemical precursors dissolved in the first precursor. The first processing apparatus may be a flame sprayer, hot air sprayer, or plasma sprayer. With a flame sprayer, the first precursor is flowed into the nozzle using a flammable gas such as methane or acetylene, along with an oxygen source such as air or oxygen gas. A ignitable gas is ignited to release energy into the first precursor, and typically the first precursor is atomized to evaporate liquids from the first precursor and crystallize dissolved solvents. The solution may be atomized using an inert gas such as nitrogen, argon, or helium, or one of the reactant gases such as a flammable gas, an oxygen source, or a combined flammable mixture of a flammable gas and an oxygen source. There will be.

Typically, the first processing apparatus dries the electrochemical precursors by evaporating or reacting liquid carriers in the first precursor, thereby crystallizing the electrochemical precursors into a powder. Oxidation reactions performed in the first processing apparatus are performed to add the desired amount of energy to the drying or crystallization process without causing oxidation of the electrochemical precursors. In most cases, less than about 1% of the electrochemical precursors will react with oxygen in the first processing device.

Carbon-containing species in the first precursor may provide other results. Carbon-containing precursors contained within the first precursor may also be oxidized to add energy in addition to the reactant gases in a drying operation. Amorphous carbon particles may be formed and may be mixed with the powdered crystals generated from the flame sprayer. In addition, the carbon-containing solvents in the first precursor, together with the electrochemical precursors in the powder, may form crystallized or amorphous particles or produce a mixture of both. As will be described further below, adding carbon to the crystals may provide advantages in the performance of the finally deposited film and during processing.

Instead, hot air may be mixed with the first precursor in the sprayer for drying. Hot air may be used to atomize the first precursor, or the first precursor may be atomized using an inert gas, as described above, and then mixed with the hot air. Any carbon-containing liquids in the first precursor may be oxidized upon exposure to hot air and may leave carbon in the powder.

In addition, a plasma sprayer may be used to convert the first precursor into a powder. The first precursor is atomized into an activation chamber of the plasma sprayer, where electrical energy such as DC or RF is coupled to the atomized precursor. The electrical energy may crystallize the electrochemical solvents by raising the temperature of the first precursor, or a reactive material such as a hydrocarbon gas may be added to the mixture to release energy and raise the temperature of the mixture. Similarly, carbon-containing species in the first precursor result in carbon inclusions in the powder from the plasma spray process.

Generally, an energy source, flame, plasma, or hot air to the sprayer is established prior to providing the first precursor. In a flame spray embodiment, the flammable gas is ignited with an oxygen source, followed by atomization of the first precursor into the flame formed. In a hot air embodiment, the flow of hot air is formed prior to the flow of the atomized precursor begins. In a plasma spray embodiment, a plasma is formed using an inert gas flow into the plasma sprayer, followed by the flow of the precursor mixture. The flow of the first precursor to the first processing apparatus is increased until the energy input to the first precursor reaches the lower limit necessary to achieve the desired processing, such as drying. In a continuous drying process, the degree of drying may be controlled by adjusting the flow of the first precursor to the first processing apparatus. The energy input may be controlled by adjusting the flow or proportion of the flammable gas or oxygen source, or by adjusting the temperature or flow of the hot air.

In general, energy moisture is removed from the powder by an energetic process. The first precursor is heated to a temperature of 200 ° C. or higher to evaporate the liquid and crystallize the solvents. Valves or openings in the first processing device may increase the pressure drop through the first processing device, thus facilitating evaporation. The powder may be completely dried by an energetic spray process or, if necessary, some moisture may be left to volatilize after spraying. Particle size may be controlled by processing temperature and atomization flow. In general, finer atomization and higher temperatures produce smaller crystals. In the processing step, it is generally desirable to avoid oxidation up to a large range of metal solvents. As such, the temperature of the first processing step is typically less than about 800 ° C. In higher severity processing, nanocrystals may be formed. After spraying, the powder is typically maintained at a temperature of 200 ° C. or higher to finish drying and to prevent aggregation and moisture accumulation following drying.

In step 206, particles formed by applying energy to the first precursor are collected using a collecting device. By collecting the powder, the powder can be stored, transported, or fed to a synthesis apparatus for deposition on a substrate. Further drying may also take place in the collecting device. In addition, the collection device may be sealed to prevent moisture ingress after collection. The collection device may be a cyclone separator, or other centrifugal force separator, or a hopper, any of which may be electrostatically assisted. The powder is dispensed from the first processing device to the feed point of the collection device. In the case of a cyclone separator, the first processing apparatus may be configured to dispense the powder to the tangential feed point of the cyclone separator. In the case of a hopper, the powder may be dispensed into the central portion of the hopper. Instead, a centrifugal force separator, such as a cyclone separator, may be configured to dispense the collected powder into the hopper.

In step 208, the collected powder is supplied to the second processing apparatus to synthesize the electrochemically active materials and to deposit the materials onto the substrate. To aid the supply to the second processing apparatus, the powder may be mixed with a fluidizing gas. Oxygen containing gas is mixed with the powder and energy is added to the mixture to initiate the reaction of oxygen with the powder. Energy input can be achieved through combustion of the combustible gas mixture, or via plasma. In a plasma embodiment, the fluidizing gas may be a plasma forming gas such as argon or nitrogen. Carbon may be added to the reaction mixture within the second processing apparatus and also via liquids such as carbon-containing gases such as hydrocarbon gases, or organic fluids that may carry carbon-containing solvents. The carbon-containing gas or liquid may be supplied with the powder and mixed, or may be provided through an independent route. In one embodiment, a carbon-containing gas may be optionally used with an inert gas to fluidize the powder for supply to the second processing apparatus.

Carbon may be advantageous as an inclusion in the deposited negative electrode material as a binder for the deposited layer, and the conductivity of carbon improves film performance. Carbon addition may also prevent evaporation of the electrochemical material particles during the synthesis operation at high temperatures by forming a low molecular weight amorphous carbon coating on the particles. The coating controls the energy input into the particles so that the synthesis reaction proceeds without evaporation of the electrochemical material.

The second processing apparatus distributes a stream of crystals or nanocrystals of an electrochemically active material of the general formula LiNi _w Mn _x Co _y O _z , wherein w, x, and y are each about .3 to 1.5, z is about 1.5 to 2.5. If the second processing apparatus is a plasma sprayer, the plasma is ejected from the apparatus with crystals entrained in the stream of hot gas and plasma. The crystals may exit the processing chamber at a speed of about 1 m / sec to about 600 m / sec, for example about 100 m / sec, and the stream forming the plasma jet may be about 0.1 to 1.5 m, for example For example, it has a length of about 1 m. Typically, the substrate is located about 0.1 to 1.5 m from the plasma chamber.

In each processing stage, a carbon-containing gas, which may be a hydrocarbon such as methane, ethane, acetylene, propane, or other fuel, is added to the first or second processing apparatus, for example by mixing with an atomizing gas. It may be possible, or may be provided to the device independently, so that carbon may be added to the mixture and, if necessary, to control the energy release of the processing stage. The carbon-containing gas may add more carbon than the carbon in the precursor mixture, or all carbon may be added through the carbon containing gas. Oxygen may be mixed with the carbon containing gas to provide a more energetic reaction in any of the flame spray, plasma spray, or hot air spray embodiments. By adjusting the flow rates of the carbon containing gas, the carbon components of the electrochemical precursor, or both, the total carbon content of the deposited film may be controlled. In addition, the reaction temperature may be controlled by adjusting the flow rates of the carbon-containing gas and / or oxygen provided together. Hydrogen containing carrier gas may also be used to control the temperature of the processing. According to an embodiment, the processing temperature is typically maintained at about 200 ° C to about 2,000 ° C. In the case of flame spray embodiments, the temperature is typically maintained between about 200 ° C and about 1,000 ° C, for example between about 400 ° C and about 800 ° C. In the case of a plasma spray embodiment, the temperature is typically maintained at about 600 ° C. to about 2,000 ° C., such as about 800 ° C. to about 1,600 ° C., such as about 900 ° C.

As the stream is moved towards the substrate, the additive may mix with the crystals outside the processing apparatus. Generally, additives are provided to help bind the electrochemical crystals to the substrate. The additive may include a binding agent, such as a polymer, to retain the crystals on the surface of the substrate. The bonding agent may have some electrical conductivity to improve the performance of the deposited layer. In one embodiment, the binding agent is a low molecular weight carbon containing polymer provided at a rate of less than about 100 polymer molecules per nanocrystalline sugar. To facilitate the attachment of nanoparticles to the substrate, the low molecular weight polymer may have a weight average molecular weight of less than about 3,000,000 g / mol. The ratio of polymer molecules to crystals provides space between the crystals and promotes adhesion without disturbing substantial free flow through the deposited layer of electrons and ions.

Typically, the additive is provided as a liquid, for example as a solution, suspension, or emulsion. In one embodiment, the additive is a modified styrene-butadiene louver ("SBR") material in a water emulsion that is sprayed into the crystal stream exiting the processing chamber. The flow rate of the binder precursor is generally about 10% to about 75%, for example about 20% of the mass flow rate of the crystals exiting the second processing apparatus.

If the additive is mixed inside with the stream of crystals, the mixing position is determined for its energy content. Residual heat in the crystal stream evaporates the continuous phase or solvent of the liquid, thus freeing the additive to contact the crystals. In most such cases, the additive is at a distance from the discharge point of the second processing device that is about 60% to about 90%, for example about 70% to about 80% of the distance from the second processing device to the substrate. Is provided.

In step 210, nanocrystals and additives are formed in the deposited layer on the substrate. The minimum amount of additive occupies the lattice interstices between the crystals to adhere the crystals to the film while allowing free flow of electrons and ions through the deposited layer. In some embodiments, the deposition agent and crystals in the crystals may be heated during film formation to facilitate close settling of the crystals before any residual carbon is cured. As long as the binding medium does not become too resistant to motion, subsequent settlement of the crystals exiting from the second processing apparatus is facilitated by dense settlement of the crystals.

The composition of the electrochemical precursor may be changed to change the composition of the deposited electrochemically active layer. LiMn ₂ O ₄ To make a spinel material such as, for example, an electrochemical precursor can be made using 100 mL of 1M LiNO ₃ solution and 200 mL of 1M Mn (NO ₃ ) ₂ solution with an appropriate amount of oxygen containing materials. Could be. A high capacity layer may be formed by depositing a nickel rich, for example about 60% or more, lithium based material. In contrast, by depositing a lithium-based material that is relatively low in nickel, for example less than about 40% by weight, a high stability layer may be formed. Nickel-rich materials are less stable because nickel tends to react with many electrolytes used in battery formulations. As mentioned above, this trend may be controlled by forming a shell of high stability around the high capacity core.

In alternative embodiments, the particles may be coated with materials other than carbon for synthetic processing. Coatings of alumina, aluminum fluoride, aluminum phosphate, aluminum hydroxide may be used. Aluminum may be added in the process as aluminum alkyls, for example as trimethylaluminum. Fluorine may be added as HF. Phosphorus may be added as hydrogen phosphide, ie PH ₃ . Generally, the coating material is applied at the stage of the synthesis process after oxidation of the electrochemical metals.

In some embodiments, a shell may be formed between each crystal and its coating prior to the deposition of the crystals on the substrate. By providing to the second processing apparatus an electrochemical precursor having a composition different from that of the first precursor described above, the shell may be formed. The material provided to form the shell is generally the electrochemical material required for crystallization, so that the shell is generally near or overlapping the reaction zone where the crystals from the first processing stage react with oxygen. Is provided. For example, the shell material may be mixed with the powder charged into the second processing device, such that the shell material is exposed to the energy of the second processing stage, thus newly formed electrochemically prior to deposition on the substrate. Shell material crystallizes around the crystals.

In one example, to prevent a reaction between the core and the electrolyte, the shell material may be provided to cover the high capacity, low stability electrochemical core with a high stability shell. The high stability core may have a low nickel content, while the high capacity core may be an electrochemical mixture with a high nickel content. The high nickel content of the core may cause chemical reactions with some electrolyte materials. Forming a low nickel content shell around the high capacity core prevents such chemical reactions while preserving the capacity of the core.

The porosity of the deposited film may be controlled by adjusting the rate at which the stream of crystals exits the distributor device. Increasing such speed generally lowers the porosity of the film. The size of the crystals may be controlled by the severity of the drying or the degree of atomization. For example, finer atomization, by raising the pressure of the atomizing gas, results in smaller particles.

3 is a schematic cross-sectional view of an apparatus 300 according to one embodiment. The apparatus 300 includes a processing chamber 302, a substrate support 304, and a dispenser 306, which in some embodiments may be a dispenser that dispenses material according to a particular desired pattern. .

The distributor 306 includes an activation chamber 308 and a nozzle 320 through which the activated precursor mixture exits the distributor 306. The first precursor mixture is provided to the activation chamber 308 through a first source conduit 336 in fluid communication with a precursor source (not shown), which activates an atomizer for liquid, slurry, or suspension precursors. It may be characterized. The first source conduit 336 delivers the first precursor mixture to the flow controller 334, which controls the flow of the first precursor through the first precursor delivery conduit 312 to the activation chamber 308. . The nozzle 320 delivers the activated first precursor mixture from the activation chamber 308 through the opening 318 to the mixing zone 322 near the end of the nozzle 320.

The first precursor in the activation chamber 308 is exposed to an electric field coupled into the inner portion 310 of the activation chamber 308 by an electrical energy source 352. Although shown as a DC source in the embodiment of FIG. 3, the power source 352 may be an RF or DC source. Electrical insulators 330 may be disposed within the walls of distributor 306 to confine electrical energy to activation chamber 308.

The mixing zone 322 may be an enclosure or confined space near the activation chamber 308 configured to direct the gas mixture toward the substrate in the desired pattern as the mixture reacts. In one example, a second precursor, which may be carbon, oxygen or both, is provided around the nozzle 320 via the annular path 328. The annular path 328 is configured to flow the second precursor into the activated first precursor in a uniform manner upon exiting the nozzle 320. As the precursor streams are mixed, the active species in the first precursor can react with the components of the second precursor to generate heat to promote the nanocrystallization process, and the nanocrystals having a pattern unfolding the activated material. It may be possible to create pressure to push outward into the stream. The precise geometry of the mixing zone 322 and the nozzle 320 may be adjusted to achieve any desired flow pattern or mixing method. The exact mixing method devised may help to control the heat transfer to the nanocrystals. For example, a mixing method that includes a vortex flow of first and second precursors may be useful in controlling the application of heat to nanocrystals from mixing zone reactions that may include combustion reactions. will be.

The second precursor is delivered to the mixing zone 322 by a second precursor source conduit 338 in fluid communication with a second precursor source (not shown). The second precursor flows through the flow controller 334 into the second precursor delivery conduit 314 into the annular path 328.

The third precursor may be delivered through the flow controller 334 from the third precursor source conduit 340, in fluid communication with the third precursor source (not shown), through the third precursor delivery conduit 316. The third conduit 324 is configured to dispense the third precursor in a pattern substantially overlapping the pattern of impact on the substrate by the crystal stream such that the crystals are fixed on the substrate by the third precursor. Will be able to have The third precursor may be the binding agent cited above. Typically, it should be noted that the binding agent is not added to the powder exiting the first processing apparatus described above with respect to FIG. 2, whereby the apparatus of FIG. 3 is the first processing apparatus of method 200 as such. Is used, and no third precursor will be provided.

In the apparatus of FIG. 3, the dispenser 306 may be moved relative to the substrate support 304 and thus may form a film over all or a substantial portion of the substrate disposed on the substrate support 304. This may be accomplished by moving the dispenser 306, the substrate support 304, or both. For example, dispenser 306 may be configured to extend and retract across chamber 302 using actuators. Alternatively, or in addition, the substrate support 304 may have a positioning mechanism, such as a precision x-y stage, schematically indicated at 344.

Exhaust gases exit chamber 302 through exhaust portal 330, which may have a conventional configuration. The portal 330 may be one opening in the wall of the chamber 302, as shown in FIG. 3, or may be a plurality of such openings, or circumferentially disposed along the circumference of the chamber 302. It may be an exhaust channel. The exhaust portal 330 includes a particle trap 342 to prevent particles produced by the distributor 306 from reaching the vacuum pumps and other processing equipment downstream of the chamber 302. Particle capture 342 may be any suitable device such as a filter or a vortex separator.

4 is a schematic cross-sectional view of an apparatus 400 according to another embodiment. The device 400 is mostly similar to the device 300 of FIG. 3. Apparatus 400 includes a processing chamber 402, a substrate support 404, and a dispenser 406, which in some embodiments may be a dispenser that dispenses material according to a particular desired pattern. .

The distributor 406 includes an atomization chamber 408 and a nozzle 420 through which the atomized precursor mixture exits the distributor 406. The first precursor mixture is provided to the atomization chamber 408 through a first source conduit 436 in fluid communication with a precursor source (not shown). The first source conduit 436 delivers the first precursor mixture to the flow controller 434, which controls the flow of the first precursor through the first precursor delivery conduit 412 to the atomization chamber 408. . In general, the atomization gas is mixed with the first precursor mixture in the first precursor delivery conduit 412. The nozzle 420 transfers the atomized first precursor mixture from the atomization chamber 408 through the opening 418 to the energy input zone 422 near the end of the nozzle 420.

The energy input zone 422 may be a confined space or enclosure near the atomization chamber 408 configured to direct the gas mixture in a desired pattern. In one example, a second precursor, which may include carbon, oxygen, or both, and may be a flammable gas mixture, is provided around the nozzle 420 through the annular path 428. The annular path 428 is configured to flow the second precursor into the atomized first precursor in a uniform manner upon exiting the nozzle 420. As the precursor streams are mixed, the second precursor delivers energy into the atomized first precursor to produce a stream of solids comprising a mixture of solvents in the first precursor. By adjusting the precise geometry of the nozzle 420 and the mixing zone 422, any desired flow pattern or mixing method may be achieved. As noted above in connection with FIG. 2, the second precursor may also be a hot gas that cannot be ignited, such as hot air.

The second precursor is delivered to the mixing zone 422 by a second precursor source conduit 438 in fluid communication with a second precursor source (not shown). The second precursor flows through the flow controller 434 into the second precursor delivery conduit 414 into the annular path 428.

The third precursor may be delivered through flow controller 434, through third precursor delivery conduit 416, from third precursor source conduit 440 in fluid communication with a third precursor source (not shown). The third conduit 424 may have a dispensing head configured to dispense the third precursor in a pattern that substantially overlaps the pattern of impact on the substrate such that the nanocrystals are fixed on the substrate by the third precursor. As in the apparatus 300 of FIG. 3, if the apparatus 400 of FIG. 4 is used as the processing apparatus of the method 200, no third precursor is provided to the apparatus 400.

In the apparatus of FIG. 4, the dispenser 406 may be moved relative to the substrate support 404 and thus may form a film over all or a substantial portion of the substrate disposed on the substrate support 404. This may be accomplished by moving the dispenser 406, the substrate support 404, or both. For example, dispenser 406 may be configured to extend and retract across chamber 402 using an actuator. Alternatively, or in addition, the substrate support 404 may have a positioning mechanism, such as a precision x-y stage, schematically indicated at 444.

Exhaust gases exit chamber 402 through exhaust portal 430, which may have a conventional configuration. The portal 430 may be one opening in the wall of the chamber 402, as shown in FIG. 4, or may be a plurality of such openings, or circumferentially disposed along the circumference of the chamber 402. It may be an exhaust channel. The exhaust portal 430 includes a particle capture 442 to prevent particles produced by the distributor 406 from reaching the vacuum pumps and other processing equipment downstream of the chamber 402. Particle capture 442 may be any suitable device, such as a filter or a vortex separator.

5A is a schematic diagram of an apparatus 500 for forming an electrochemical layer on a substrate. Apparatus 500 includes a first processing stage 502, a collection stage 504, and a second processing stage 506. The first processing stage 502 may be a drying apparatus and may include a thermal or plasma sprayer. The collection stage 504 collects materials from the first processing stage 502 into the solids receiver and supplies the solids to the second processing stage 506. The second processing stage 506, which may be a composite device, dispenses material towards the substrate 508 to form an electrochemical layer on the substrate. Apparatus 500 may be used to perform the method 200 of FIG. 2.

The first processing stage 502 includes a first distributor 510, a first precursor source 512, an atomizing gas source 514, and an energy component source 516. The first precursor source 512, atomizing gas source 514, and energy component source 516 may be similar to the case of the first precursor described above with respect to FIG. 2. The first dispenser 510 may generally be similar to the apparatus 300 or 400 of FIGS. 3 and 4. The first precursor source 502, along with the atomizing gas source 514, is a liquid that is supplied to the mixing location in the first distributor 510 through an atomization opening or opening to an energy input location. An energy component source 516 is supplied to the energy input location for mixing with the atomized first precursor source 502.

The first processing portion 502 distributes the powder 518 formed from the first precursor into the collecting portion 504. Collection portion 504 includes a collection device 520, which may further include solids receiver 522 and feeder 524. As discussed above in connection with FIG. 2, the solids receiver 522 may be a centrifuge, such as a cyclone, or a hopper, and may be electrostatically improved. For example, the outer wall of the cyclone separator may be energized with a weak DC voltage to promote the adhesion of particles of powder 518 to the walls, thus facilitating the separation of the powder from the gas. The separated powder may thus be dropped into the feeder 524 or directly into the conduit and supplied to the second processing portion 506. Thus, the collection device 520 may consist of a separator, a feeder, or both.

5B is a cross-sectional view of a cyclone separator 522A according to another embodiment. Dispenser 510 is shown to dispense powder 518 into the tangential feed point of separator 522A. Solids are collected and exit the cyclone distributor 522A through the solid discharge portal 545, and most of the gas exits through the gas discharge portal 550. Solids exiting the cyclone distributor 522A through the solid discharge portal 545 may be collected in the feeder 524 of the collection stage 504.

Solids collected in the collection stage 504 are provided to the second processing portion 506 through the conduit 526. Gas may be blown through conduit 526 to aid in the movement of crystalline powder into second processing portion 506. The second processing portion 506 is a second distributor 528, which may be generally similar to the apparatus 300 of FIG. 3 or the apparatus 400 of FIG. 4, and the electrochemical determination exiting the second distributor 528. And a third dispenser 536 for dispensing the additive for co-depositing with the electrodes 530. Precursor 540 for the additive is supplied to the third distributor 538. The third distributor 538 is generally oriented to dispense the additive over the same area where the crystals 530 are deposited. As noted above, insertion of the additive stream into the crystal stream is selected to remove the desired amount of liquid from the additive stream.

An energy generating precursor 532 and an oxygen containing precursor 534 are provided to the second distributor 528 to form electrochemical crystals. The energy generating precursor 532 may be a plasma holding gas such as argon, helium or hydrogen, or a ignitable gas such as any of the foregoing hydrocarbons.

The apparatus 500 of FIG. 5A features two separate processing stages for producing electrochemically active materials for deposition on a substrate. Although the aforementioned electrochemical precursor solutions can be converted directly into electrochemically active materials in a single processing stage, the dispenser design is complicated by handling various precursors, additives and energy providing precursors. For example, drying the electrochemical precursors in the first stage and separation by synthesizing the electrochemically active materials in the synthesis stage reduces the complexity of the dispenser design and the footprint of the device.

While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof.

Claims (15)

An apparatus for forming an electrochemical layer on a substrate:
A first processing stage having a dry energy source, an atomizing gas source, and a liquid precursor source coupled to the first distributor;
A collection stage near said first distributor, said collection stage having solids receptors; And
And a second processing stage having a second distributor near the collection stage and a source of activation energy coupled to the second distributor. The method of claim 1,
And the first distributor is a thermal sprayer and the second distributor is a plasma sprayer. 3. The method according to claim 1 or 2,
Wherein the source of dry energy is a hot gas or a flammable gas mixture. The method of claim 3, wherein
And the solids receiver is a cyclone distributor. The method of claim 1,
And the first distributor is a thermal sprayer and the second distributor is a plasma sprayer, and the solids receiver is a cyclone distributor. The method of claim 5, wherein
And the thermal sprayer is located near the tangential feed point of the cyclone dispenser. The method according to claim 5 or 6,
A mixing position for the first processing stage to mix the liquid precursor and the atom and gas, an atomization orifice through which mixed liquid precursor and atomization gas flows pass, and drying in which the dry energy source is mixed with the atomized liquid precursor And a location, the apparatus for forming an electrochemical layer on the substrate. The method of claim 7, wherein
Further comprising a third dispenser,
And the second and third distributors are oriented to mix the two streams together. An apparatus for depositing an electrochemical layer on a substrate:
A drying station, a collection station, a synthesis station, and additive nozzles,
The drying station includes a thermal spray nozzle having an atomizing gas source and a liquid precursor source coupled to the mixing site, an atomization aperture that separates the mixing site from the drying location, and a chemical or thermal drying energy coupled to the drying location. A source of and an output orifice near said drying location,
The collection station couples to a cyclone separator and a hopper, a tangential feed point of the cyclone separator near the output orifice of the drying station, solids output portion of the cyclone separator near the hopper, and a wall of the cyclone separator. Includes a source of ringed electrical energy,
The synthesis station comprises a plasma spray nozzle having an inlet coupled to an outlet of the hopper and to a plasma forming gas source, and a power supply coupled to the plasma spray nozzle, and
And the additive nozzle is located at a defined distance from the outlet of the plasma spray nozzle. As a method of forming an electrochemical layer on a substrate:
Forming a precursor powder from the liquid precursor using a continuous drying process;
Forming an electrochemical precursor from the precursor powder by reacting the precursor powder with oxygen in a plasma process;
Distributing the electrochemical precursor in a stream towards the substrate;
Adding a polymer binder to the stream to form a deposition mixture; And
Depositing the deposition mixture on the substrate. 11. The method of claim 10,
And the liquid precursor is an aqueous solution of metal salts comprising at least one of lithium, nickel, manganese, cobalt, and iron. The method of claim 11,
And the liquid precursor further comprises carbon. 13. The method according to claim 11 or 12,
And wherein said metal salt is a nitrate. 13. The method according to any one of claims 10 to 12,
And the continuous drying process is a flame spray process. 11. The method of claim 10,
Wherein the polymer binder is added to the stream as a liquid and residual heat from the stream evaporates the liquid prior to the deposition mixture being deposited on the substrate.

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