Systems and methods for depositing separator materials

Abstract

One variation of this method includes receiving a portion of a substrate tape including a substrate in a coating zone; depositing separator material droplets onto the first substrate, each droplet of the separator material droplets including a first solvent, a first polymer, and a second polymer; heating the substrate and the portion of separator material to a first temperature; washing the separator material droplets and substrate with the second solvent to dissolve the second polymer from the separator material droplets to form an open cell network of pores; and irradiating the separator material droplets to crosslink the first polymer and form a discrete separator layer having an open cell network of pores.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 330,763, filed April 13, 2022, which is incorporated herein by reference in its entirety.

[0002]

[0002] The present invention relates generally to the field of battery technology, and more particularly to new and useful systems and methods for depositing separator materials in the field of battery technology. [Brief explanation of the drawings]

[0003] [Figure 1] FIG. 1 is a flow chart of the method. [Figure 2]

[0004] FIG. 2 is a flow chart representation of one variation of the method. [Figure 3]

[0005] FIG. 3 is a flow chart representation of one variation of the method. [Figure 4]

[0006] FIG. 4 is a flow chart representation of one variation of the method. [Figure 5]

[0007] FIG. 5 is a flow chart representation of one variation of the method. DETAILED DESCRIPTION OF THE INVENTION

[0004]

[0008] The following description of preferred embodiments of the present invention is not intended to limit the invention to these preferred embodiments, but rather to enable one skilled in the art to make and use the present invention. The variations, configurations, implementations, example implementations, and examples described herein are optional and are not limited to the variations, configurations, implementations, example implementations, and examples described. The invention described herein can include all permutations of these variations, configurations, implementations, examples, and examples.

[0005] 1. Method

[0009] As shown in FIGS. 1-5, method S100 includes, during a first period of time, receiving a first substrate in a coating zone in block S110, spray-coating a group of separator material droplets onto the first substrate in block S120, where each droplet in the group of separator material droplets includes a first solvent, a first polymer miscible in the first solvent, and a second polymer miscible in the first solvent, and accessing a target substrate temperature below the boiling point of the first solvent in block S122.

[0006]

[0010] The method S100 also includes, during a second time period subsequent to the first time period, heating the first substrate and the separator material droplets to a target substrate temperature in block S130 to evaporate the first solvent from the separator material droplets and promote phase separation of the second polymer from the first polymer; washing the separator material droplets with a second solvent in block S140 to dissolve the second polymer from the separator material droplets and form an open-cell network of pores in the separator material droplets; and irradiating the separator material droplets and the first substrate in block S150 to crosslink the first polymer and form a separator membrane on the first substrate, the separator membrane defining an open-cell network of pores sized to transport ions.

[0007] 1.1 Variation: Separator Thickness

[0011] One variation of method S100 includes receiving a substrate within a coating zone during a first period of time in block S110; defining a target liquid temperature range for the separator material in block S112; heating a spray nozzle facing the substrate and connected to a reservoir volume of the separator material in a liquid state to the target liquid temperature range in block S114; detecting a first temperature of the separator material at the spray nozzle in block S116; spray-coating a first volume of separator material, including a first solvent, a first polymer miscible in the first solvent, and a second polymer miscible in the first solvent, onto the substrate through the spray nozzle in response to the first temperature of the separator material falling within the target liquid temperature range in block S120; and accessing a target substrate temperature below the boiling point of the first solvent in block S122.

[0008]

[0012] This variation of method S100 also includes, during a second time period following the first time period, heating the substrate and the volume of first separator material to a target substrate temperature in block S130 to evaporate a first solvent from the volume of first separator material, dissolving a second polymer from the volume of first separator material to form an open-cell network of pores in block S140, and irradiating the volume of first separator material to crosslink the first polymer and form a separator membrane having a separator thickness near the target separator thickness in block S150.

[0009] 1.2 Variation: Discrete separator

[0013] One variation of method S100 includes, during a first period, receiving a portion of a substrate tape including a first substrate in a coating zone in block S110, and depositing a group of separator material droplets on the first substrate in block S120, wherein each droplet in the group of separator material droplets includes a first solvent, a first polymer, and a second polymer.

[0010]

[0014] This variation of method S100 includes heating the first substrate and the separator material droplets to a first temperature in block S130 during a second time period following the first time period; washing the separator material droplets and first substrate with a second solvent in block S140 to dissolve the second polymer from the separator material droplets and form an open-cell network of pores within the separator material droplets; and irradiating the separator material droplets in block S150 to crosslink the first polymer and form a discrete separator layer having an open-cell network of pores sized to transport ions through the separator layer.

[0011] 2. Application Examples

[0015] Generally, the substrate supply station, spray coating system, replenishment station, cleaning station, and irradiation station (hereinafter "system 100") work together to perform each block of method S100 to deposit separator material as an aerosol (or "constellation," "mist," or "cloud") onto a substrate (e.g., electrode, cathode, anode) to form a thin separator film of uniform thickness (discrete separator layer, permeable separator film, etc.) on the substrate.

[0012]

[0016] More specifically, the separator material comprises a homogeneous polymer-polymer-solvent liquid mixture comprising a first solvent, a first polymer miscible in the first solvent, and a second polymer miscible in the first solvent. In one example, the first solvent comprises an organic ketone such as butanone, the first polymer comprises a copolymer such as poly(vinylidene fluoride-hexafluoropropylene) (or "PVDF-HFP"), and the second polymer comprises a polyether such as polyethylene oxide (or "PEO"), poly(oxyethylene) (or "POE"), or polyethylene glycol (or "PEG"). In this example, the first polymer (e.g., PVDF-HFP) and the second polymer (e.g., PEG) are mixed in the first solvent (e.g., butanone) to form a homogeneous polymer-polymer-solvent liquid mixture representing 80% or more by weight of the first solvent.

[0013]

[0017] Thus, system 100 executes blocks of method S100, during a processing cycle, spray-coating a volume of separator material onto a substrate, heating the substrate to rapidly dry the volume of separator material in contact with the substrate, evaporating a first solvent (e.g., butanone) from the volume of separator material, washing or rinsing the substrate in a chemical bath of a second solvent comprising an alcohol (e.g., isopropanol) to dissolve a second polymer (e.g., PEG) from the volume of separator material to form an open-cell network of pores, and irradiating the volume of separator material with an electron beam to further crosslink the first polymer (e.g., PVDF-HFP) to form a separator membrane of uniform thickness and defining an open-cell network sized to transport ions (e.g., lithium ions) through the separator membrane.

[0014]

[0018] Additionally, system 100 can further monitor the gaseous environment within the vessel and the temperature of the liquid separator material in the reservoir of the coating supply subsystem to maintain a target vapor pressure and homogeneous polymer-polymer-solvent liquid mixture within the reservoir. Furthermore, system 100 can utilize the target temperature range and target vapor pressure of the separator material to achieve an accurate and repeatable liquid flow rate of the separator material through the spray nozzle of the spray coating system and achieve an accurate and repeatable separator material thickness on the substrate via spray coating during the processing cycle. System 100 can also define (or access) and implement time and temperature parameters for the drying segment of the processing cycle to evaporate the first solvent (e.g., butanone) from the separator material coating the substrate and control phase separation between the first polymer (e.g., PVDF-HFP) and the second polymer (e.g., PEG).

[0015]

[0019] Additionally or alternatively, the system 100 can irradiate the volume of the separator material to form a porous electrolyte structure that extends beyond the perimeter of the substrate, and then fill the open-cell network of pores with solvated ions to form an electrolyte. For example, the system 100 can perform method blocks to form an ion-carrying (e.g., lithium-ion-carrying) electrolyte on the cathode and / or anode, which can then be assembled into a battery cell for a two-dimensional or three-dimensional battery (e.g., for an electric vehicle, wearable device, mobile phone, or battery-powered tool). Furthermore, the electrolyte can act as a buffer or electrode separator between the anode and cathode assembled into the battery cell, preventing the flow of electrons between the anode and cathode within the battery cell and preventing electrical shorts within the battery.

[0016]

[0020] Method S100 is described below as being performed by system 100 to deposit (e.g., spray coat) a separator material onto a substrate (e.g., an electrode) and form a thin film of separator material, or a discrete separator layer, or a permeable separator membrane on the substrate through a processing cycle. However, method S100 can also be performed to produce a thin film of separator material, a discrete separator layer, or a permeable separator membrane directly on a cathode and / or anode, and / or to fabricate a separate, continuous, non-conductive structure for later assembly with an anode and cathode to form a two-dimensional or three-dimensional battery, etc.

[0017] 3. System

[0021] System 100 includes a substrate supply station 105, a spray coating system 110, a replenishment station 120, a cleaning station 130, and an irradiation station 140. Substrate supply station 105 includes a substrate reel (e.g., an electrode reel, an anode reel, a cathode reel) configured to transport a substrate tape containing a series of substrates to spray coating system 110. Spray coating system 110 includes a chassis 112, a multi-axis stage 113, a spray nozzle 114, a coating supply subsystem 115 configured to selectively supply liquid separator material (e.g., a polymer-polymer-solvent liquid mixture) from a reservoir to spray nozzle 114, a gas regulator 116, a set of heaters 117, and a set of temperature sensors 118. Spray coating system 110 is configured to spray coat volumes of separator material onto substrates.

[0018]

[0022] The refill station 120 includes a new supply of separator material (e.g., a polymer-polymer-solvent liquid mixture) and is configured to replenish the spray coating system reservoir with the new supply of separator material. The cleaning station 130 includes a chemical bath of a second solvent, such as an alcohol (e.g., isopropanol), configured to dissolve the second polymer from the separator material on the substrate. The irradiation station 140 includes an electron beam configured to deliver electrons toward the substrate to crosslink the first polymer and form a separator film (e.g., a discrete separator layer, a permeable separator film) on the substrate.

[0019] 3.1 Substrate supply station

[0023] In one embodiment, the substrate supply station 105 includes a substrate reel (e.g., an electrode reel, an anode reel, a cathode reel) configured to transport a substrate tape including a series of substrates to the spray coating system 110. In particular, the substrate supply station 105 includes a substrate reel configured to transport a cathode tape including a series of cathodes and / or an anode tape including a series of anodes from the substrate supply station to the spray coating system 110.

[0020]

[0024] In one variation, system 100 can trigger substrate supply station 105 to load a substrate reel with cathode tape and transport the cathode reel, including a first cathode in a series of cathodes, from the substrate supply station to a coating zone within spray coating system 110. System 100 can then receive a first section of cathode tape, including the first cathode, within the coating zone and perform the methods and techniques described below to spray coat a separator material onto the first cathode occupying the coating zone, dry the separator material on the first cathode, rinse the first cathode in an alcohol bath, and irradiate the separator material and the first cathode with an electron beam to form a separator film on the first cathode within the first section of cathode tape.

[0021]

[0025] Additionally or alternatively, system 100 can trigger substrate supply station 105 to load anode tape onto a substrate reel and transport the anode reel containing a first anode of a series of anodes from the substrate supply station to a coating zone within spray coating system 110. System 100 can then receive a first section of anode tape containing the first anode into the coating zone and perform the methods and techniques described below to spray coat a separator material onto the first anode occupying the coating zone, dry the separator material on the first anode, rinse the first anode in an alcohol bath, and irradiate the separator material and first anode with an electron beam to form a separator film on the first anode in the first section of anode tape.

[0022]

[0026] The system 100 can repeat these methods and techniques for each other cathode in the series, each other anode in the series, and each other section of the substrate tape to transport the substrate tape (e.g., cathode tape, anode tape) to the spray coating system 110.

[0023] 3.1 Spray Coating System

[0027] The spray coating system 110 includes a chassis 112 , a multi-axis stage 113 , a coating delivery subsystem 115 , a gas regulator 116 , a set of heaters 117 , and a set of temperature sensors 118 coupled to the coating delivery subsystem 115 .

[0024]

[0028] Chassis 112 defines a coating zone and is arranged around spray coating system 110. Multi-axis stage 113 is configured to support coating supply subsystem 115. Coating supply subsystem 115 is supported by multi-axis stage 113 and includes a vessel configured to contain a gaseous environment above a reservoir configured to contain a liquid separator material (e.g., a polymer-polymer-solvent liquid mixture), a first heater 117 configured to heat the reservoir of separator material in a liquid state, a spray nozzle 114 coupled to the reservoir, facing the substrate, and configured to spray-coat a volume of separator material from the reservoir onto the substrate, a second heater 117 coupled to spray nozzle 114 and configured to heat the separator material prior to spray-coating the substrate, and a valve interposed between the reservoir and spray nozzle 114.

[0025]

[0029] A gas regulator 116 is coupled to the coating supply subsystem and configured to regulate the gas pressure within the vessel of the coating supply subsystem 115. In one variation, the gas regulator 116 can increase the pressure of the gas within the vessel and through the spray nozzle 114 to remove excess separator material that may accumulate within the spray nozzle 114 over a period of time (e.g., one week, three weeks, one month).

[0026]

[0030] The temperature sensors 118 may include a set of temperature sensors 118 configured to output signals corresponding to the temperature of the separator material in the reservoir, the temperature of the separator material at the spray nozzle 114, and the temperature of the substrate.

[0027] 3.1.1 Chassis + Gantry

[0031] The chassis 112 defines a coating zone and is disposed around the spray coating system 110. The chassis 112 is configured to support a multi-axis stage and a coating delivery subsystem 115.

[0028]

[0032] The multi-axis stage 113 includes a three-axis gantry (e.g., X-axis, Y-axis, and Z-axis) that is supported by the chassis 112, positioned over the substrate occupying the coating zone, configured to face one side of the substrate (e.g., positioned above, below, or adjacent to the substrate), and configured to support the coating delivery subsystem 115 over a range of vertical, lateral, and longitudinal positions to allow the spray nozzle 114 to access the edge of the substrate (e.g., electrode) during a processing cycle.

[0029]

[0033] In one variation, the multi-axis stage includes a five-axis gantry (e.g., X-axis, Y-axis, Z-axis, A-axis, and B-axis) supported by a chassis 112, positioned over a substrate occupying a coating zone, configured to face one side of the substrate, and configured to support the coating delivery subsystem 115 through a range of vertical, lateral, longitudinal, and rotational positions to allow the spray nozzle 114 to access the edge of the substrate (e.g., electrode) during a processing cycle.

[0030] 3.1.2 Coating Supply Subsystem

[0034] The coating supply subsystem 115 is supported by a multi-axis stage 113 and includes a container configured to contain a gaseous environment of the separator material, a reservoir disposed within the container and configured to contain the separator material in a liquid state, a spray nozzle 114 coupled to the reservoir and facing the substrate, a first heater 117 configured to heat the separator material, a second heater 117 coupled to the spray nozzle 114 and configured to heat the separator material prior to spray coating the substrate, a first valve interposed between the reservoir and the spray nozzle 114, and a second valve disposed near the spray nozzle 114.

[0031]

[0035] The first valve is operable between an open position to deliver the separator material in a liquid state from the reservoir to the spray nozzle 114 and a closed position to maintain the separator material in a liquid state in the reservoir and a gaseous environment within the container. The second valve is operable between a closed position to prevent residual amounts of the first solvent (e.g., butanone) from entering the spray nozzle 114 and an open position to deliver residual amounts of the first solvent (e.g., butanone) through the spray nozzle 114, thereby allowing cleaning of the spray nozzle 114 without disassembly of the coating delivery subsystem 115.

[0032] 3.1.3 Temperature Sensor

[0036] In one implementation, the spray coating system 110 includes a set of temperature sensors 118 (e.g., PID sensors, thermocouples) coupled to the coating delivery subsystem 115 and / or the substrates occupying the coating zone. These temperature sensors 118 are configured to output signals corresponding to the temperature of the separator material during a processing cycle.

[0033]

[0037] In one variation, system 100 may include a first temperature sensor 118 connected to the vessel and configured to output a signal corresponding to the temperature of the separator material in the gaseous environment, a second temperature sensor 118 coupled to the spray nozzle 114 and configured to output a signal corresponding to the temperature of the separator material in its liquid state before exiting the spray nozzle 114, and a third temperature sensor 118 coupled to the spray coating system 110 and configured to output a signal corresponding to the temperature of the substrate. System 100 may then interpret the temperature of the separator material and / or the substrate, monitor this temperature, and derive a correlation between this temperature and the vapor pressure of the gaseous environment prior to commencing the coating segment of the processing cycle, as described further below.

[0034] 4. Separator material: Liquid mixture of polymer, polymer and solvent

[0038] Typically, the separator material is a polymer-polymer-solvent liquid mixture containing a first solvent, a first polymer miscible in the first solvent, and a second polymer miscible in the first solvent. The polymer-polymer-solvent liquid mixture contains 80% or more by weight of the first solvent and has a low viscosity, allowing a spray nozzle to deposit droplets (e.g., an aerosol) of the separator material onto the porous substrate, allowing it to adhere to the surface of the porous substrate.

[0035]

[0039] In one implementation, the first solvent includes an organic ketone such as butanone, which has a boiling point of 79.64 degrees Celsius or 175.26 degrees Fahrenheit. The first polymer includes a copolymer such as poly(vinylidene fluoride-hexafluoropropylene) (or "PVDF-HFP") and is characterized by a molecular weight of approximately 400,000 grams / mole. The second polymer includes a polyether such as polyethylene oxide (or "PEO"), poly(oxyethylene) (or "POE"), or polyethylene glycol (or "PEG") and is characterized by a molecular weight of approximately 20,000 grams / mole. In this implementation, the first polymer (e.g., PVDF-HFP) and the second polymer (e.g., PEG) are mixed in a first solvent (e.g., butanone) to form a homogeneous polymer-polymer-solvent liquid mixture, with the first solvent being greater than 80% by weight.

[0036]

[0040] In one variation, the polymer-polymer-solvent liquid mixture includes a first solvent (e.g., butanone) and a first polymer (e.g., PVDF-HFP) and a second polymer (e.g., PEG) mixed in the first solvent. In this variation, the system 100 can heat the polymer-polymer-solvent liquid mixture to a target liquid temperature range to maintain the polymer-polymer-solvent liquid mixture as a homogeneous mixture in the reservoir and at the spray nozzle of the coating delivery subsystem. Furthermore, the first polymer (e.g., PVDF-HFP) is immiscible with the second polymer (e.g., PEG), and vice versa.

[0037]

[0041] Further, during a processing cycle, the system 100 spray-coats the polymer-polymer-solvent liquid mixture as an aerosol (or a "cloud," "mist," or "cloud" of separator material droplets) onto the substrate occupying the coating zone. For example, the polymer-polymer-solvent liquid mixture may contain less than 20% by weight of the first solvent (e.g., 15% to 20% by weight butanone). The system 100 further rapidly dries the separator material droplets upon initial contact with the substrate, such as with a heater coupled to the substrate, thereby promoting phase separation between the first polymer (e.g., PVDF-HFP) and the second polymer (e.g., PEG). The system 100 then dissolves the second polymer (e.g., PVDF-HFP) from the separator material droplets with a volume of the second solvent, such as by washing, rinsing, or spraying the substrate with alcohol (e.g., isopropanol). As a result, the droplets of separator material from which the second polymer has been removed can form a continuous film (eg, an aerogel) that defines a void network distributed throughout its volume.

[0038]

[0042] The system 100 then selectively irradiates the separator material droplets and the substrate with an electron beam to further crosslink the molecules of the first polymer (e.g., PVDF-HFP) and form a separator membrane (e.g., a discrete separator layer, a permeable separator membrane) across the substrate. The separator membrane thus defines an open-cell network of pores sized to promote uniform and rapid ion transport, prevent defect formation on the substrate, and, as further described below, prevent electrical shorting between the substrate and the anode or cathode of the battery cell, such as due to dendrite growth from the anode into the separator membrane.

[0039] 5. Processing Cycle

[0043] At the start of a processing cycle (e.g., a spray deposition cycle, a spray processing cycle), the system 100 resets the multi-axis stage to a home position facing the coating zone. The substrate supply station then delivers a series of substrates (e.g., anodes, cathodes) to the spray coating system, occupying the coating zone. The system 100 then begins the processing cycle (e.g., a spray deposition cycle, a spray processing cycle).

[0040]

[0044] The system 100 washes or rinses the substrate with a second solvent to dissolve the second polymer from the separator material, thereby forming an open-cell network of pores. The system 100 then irradiates the separator material and substrate with an electron beam to further crosslink the first polymer to form a separator layer. The resulting separator layer is non-conductive and contains an open-cell network of pores sized to allow ions (e.g., lithium ions) to transport through the separator layer between adjacent anodes and cathodes in an assembled battery cell.

[0041] 5.1 Coating Segment

[0045] When the system 100 begins a processing cycle, the system 100 can trigger the multi-axis stage to position the coating delivery subsystem facing the substrate within the coating zone to begin the first coating segment of the processing cycle.

[0042]

[0046] Prior to commencing the first coating segment of the processing cycle, the system 100 can access a target gas temperature range of the separator material for the gaseous environment within the vessel, a target liquid temperature range of the separator material in its liquid state at the spray nozzle, and a target substrate temperature of the substrate for the drying segment of the processing cycle. Then, during the first coating segment of the processing cycle, the system 100 can deposit (or "spray coat") a volume of the separator material as an aerosol (or "separator material droplets") via the spray nozzle over all surfaces and / or edges of the substrate (e.g., anode, cathode) occupying the coating zone.

[0043]

[0047] In particular, system 100 can configure a valve disposed within a coating supply subsystem to an open position to convey a liquid separator material (e.g., a polymer-polymer-solvent liquid mixture) from a reservoir to a spray nozzle, and spray-coat a group of separator material droplets having molecules of a first polymer (PVDF-HFP) defining a small cross-sectional width greater than the minimum cross-sectional width of a lithium ion and less than the minimum cross-sectional width of the substrate thickness (e.g., 50 microns, 100 microns). In this manner, the separator material droplets can encapsulate the edges of the substrate (e.g., anode, cathode). Further, in block S120, the system 100 can spray coat a group of separator material droplets onto the substrate, each droplet in the group of separator material droplets including a first solvent (e.g., butanone), a first polymer (e.g., PVDF-HFP) miscible in the first solvent, and a second polymer (e.g., PEG) miscible in the first solvent.

[0044]

[0048] Additionally, system 100 can detect a minimum volume of separator material in a liquid state in the reservoir and track the volume of separator material exiting the spray nozzle for each coating segment of the processing cycle. System 100 can then derive a correlation with the total amount of separator material exiting the spray nozzle for each coating segment and trigger a refill station to replenish the reservoir with a new amount of separator material in response to the total amount of separator material exceeding the minimum amount of separator material.

[0045] 5.1.1 Separator material temperature and pressure adjustment

[0049] Prior to spray coating the separator material onto the substrate occupying the coating zone, the system 100 can define a target gas temperature range for the first solvent relative to the gaseous environment of the vessel and a target liquid temperature range for the separator material relative to the reservoir that will result in a target flow rate of the separator material through the spray nozzle. The system 100 can then monitor the temperature of the separator material in the vessel and reservoir based on signals from a set of temperature sensors coupled to the coating supply subsystem. Furthermore, the system 100 can use heaters coupled to the coating supply subsystem and the spray nozzle to adjust the temperature of the gaseous environment and the separator material to the target temperature ranges and maintain the target flow rate of the separator material through the spray nozzle.

[0046]

[0050] In one implementation, the system 100 can define a target gas temperature range corresponding to a target vapor pressure of the first solvent in the gaseous environment within the vessel. In particular, the system 100 can access the target gas temperature range proportional to the vapor pressure of the separator material (e.g., a polymer-polymer-solvent liquid mixture) in the gaseous environment within the vessel, detect the temperature of the first solvent in the gaseous environment, and initiate the coating segment of the processing cycle based on this temperature.

[0047]

[0051] For example, the system 100 can define a target gas temperature range for a first solvent, heat a gaseous environment in a vessel containing the gaseous environment above a reservoir of liquid separator material toward the target gas temperature range, and interpret a first temperature of the gaseous environment in the vessel based on a first signal from a first temperature sensor coupled to the coating delivery subsystem. Then, in response to the first temperature of the gaseous environment being within the target gas temperature range, the system 100 can initiate a coating segment of a processing cycle and spray-coat droplets of the separator material onto a substrate via a spray nozzle.

[0048]

[0052] In another implementation, the system 100 can similarly define a target liquid temperature range for the separator material to maintain a homogeneous polymer-polymer-solvent liquid mixture in the reservoir, detect the temperature of the liquid separator material at a spray nozzle, and initiate a coating segment of a processing cycle based on the temperature. For example, the system 100 can define a target liquid temperature range for the separator material, heat a spray nozzle connected to a reservoir of the liquid separator material and facing the substrate toward the target liquid temperature range, and interpret a first temperature of the separator material at the spray nozzle based on a signal from a temperature sensor coupled to the coating delivery subsystem. Then, in response to the first temperature of the separator material falling within the target liquid temperature range, the system 100 can initiate a coating segment of the processing cycle and spray-coat droplets of the separator material onto the substrate via the spray nozzle.

[0049]

[0053] Furthermore, the system 100 can define a target gas temperature range for the first solvent corresponding to a target liquid temperature range for the separator material, detect temperatures of the separator material in the liquid state at the spray nozzle and in the gaseous environment, and initiate a coating segment of a processing cycle based on these temperatures of the separator material in the liquid state and the first solvent in the gaseous environment. For example, the system 100 can define a target gas temperature range for the first solvent corresponding to a target vapor pressure of the separator material in the gaseous state, heat a gaseous environment in a vessel containing the gaseous environment above a reservoir of the separator material in the liquid state toward the target gas temperature range, interpret the first temperature of the gaseous environment based on a first signal from a first temperature sensor coupled to the coating supply subsystem, define a target liquid temperature range for the separator material, heat a spray nozzle coupled to the reservoir of the separator material and facing the substrate toward the target gas temperature range, and interpret a second temperature of the separator material in the spray nozzle based on a second signal from a second temperature sensor coupled to the coating supply subsystem. Then, in response to the first temperature of the gaseous environment falling within the target gas temperature range and the second temperature of the separator material falling within the target liquid temperature range, the system 100 can spray coat droplets of the separator material onto the substrate via the spray nozzle.

[0050]

[0054] Alternatively, in response to the first temperature of the gaseous environment being outside the target gas temperature range and the second temperature of the separator material being outside the target liquid temperature range, the system 100 can heat the gaseous environment toward the target gas temperature range via a first heater coupled to the container, heat the liquid separator material toward the target liquid temperature range via a second heater coupled to the spray nozzle, interpret a third temperature of the gaseous environment based on a signal from the first temperature sensor, and interpret a fourth temperature of the liquid separator material at the spray nozzle based on a signal from the second temperature sensor. Then, in response to the third temperature of the gaseous environment being within the target gas temperature range and the fourth temperature of the separator material being within the target liquid temperature range, the system 100 can spray coat droplets of the separator material onto the substrate via the spray nozzle.

[0051]

[0055] In this manner, system 100 can monitor the temperature of the first solvent in a gaseous environment and in a liquid state to maintain a target vapor pressure and a homogeneous polymer-polymer-solvent liquid mixture in the reservoir. Additionally, system 100 can utilize the target temperature range and target vapor pressure to achieve an accurate and repeatable flow rate of the separator material through the spray nozzle during the coating segment of the processing cycle to spray coat the separator material onto the substrate.

[0052] 5.1.2 Separator Thickness

[0056] In one implementation, system 100 can trigger a multi-axis stage to position a spray nozzle of a spray coating system at a target offset distance relative to a substrate within a coating zone. More specifically, system 100 can receive a target separator thickness of a separator film (e.g., a discrete separator layer, a permeable separator film) formed during irradiation with separator material droplets and select a target offset distance between the spray nozzle and the substrate that is proportional to the target separator thickness.

[0053]

[0057] In one variation, the system 100 can set a target offset distance for the spray nozzle according to the specifications of the battery (e.g., a multi-cell battery for an electric vehicle, a single-cell battery for a wearable device) and the corresponding mechanical, electrical, optical, and / or physical properties of the separator film formed on the substrate (e.g., an anode, a cathode).

[0054]

[0058] For example, a user may define battery specifications for a multi-cell battery for an electric vehicle that require a separator membrane having a target separator thickness, exhibiting low resistance, greater ion flux, target conductivity, and high mechanical strength to withstand forces applied during subsequent assembly into battery cells. System 100 may then receive the battery specifications defining a target separator thickness (e.g., 10 microns) for the separator membrane, select a target offset distance for the spray nozzle relative to the substrate based on the target separator thickness, and detect a first distance between the spray nozzle and the substrate within the coating zone by interpreting a signal from a depth sensor coupled to the coating delivery subsystem. In response to the target offset distance exceeding the first distance between the spray nozzle and the substrate, system 100 may trigger the multi-axis to adjust the spray nozzle from the first distance to the target offset distance and spray-coat droplets of separator material onto a first section of the substrate through the spray nozzle at the target offset distance. The system 100 can then spray coat a second group of separator material droplets onto a second section of the substrate and implement the methods and techniques described below to form a separator membrane that exhibits low resistance, greater ion flux, and high mechanical strength at a separator thickness approaching the target separator thickness (e.g., 10 microns ± 0.01 microns, 10 microns ± 0.1 microns).

[0055]

[0059] In this manner, the system 100 can spray coat discrete sections or segments of a substrate with separator material via spray nozzles positioned at a target offset distance from the substrate to form a thin separator film of a target separator thickness according to particular battery specifications as defined by the operator.

[0056] 5.1.3 Refilling the Reservoir with Separator Material

[0060] In one implementation, the system 100 can detect a minimum volume of separator material in a liquid state in the reservoir, track the volume of separator material exiting the spray nozzle during each coating segment of the processing cycle, and trigger a refill station to replenish the reservoir with a new volume of separator material.

[0057]

[0061] For example, during a first coating segment of a processing cycle, the system 100 can detect a minimum volume of separator material in a liquid state in the reservoir, receive a first substrate in a coating zone, define a target liquid temperature range for the separator material in a liquid state in the reservoir, detect a first temperature of the separator material at a spray nozzle, and spray-coat the first volume of separator material onto the first substrate via the spray nozzle in response to a second temperature of the separator material falling within the target liquid temperature range. Then, during a second coating segment of the processing cycle, the system 100 can receive a second substrate in the coating zone, heat the spray nozzle to the target liquid temperature range, detect a second temperature of the separator material at the spray nozzle, and spray-coat a second volume of separator material onto the second substrate via the spray nozzle in response to the second temperature of the separator material falling within the target liquid temperature range. The system 100 can then calculate a total volume of separator material on the first substrate and the second substrate based on a combination of the first volume of separator material and the second volume of separator material, and in response to the minimum volume of separator material exceeding the total volume of separator material, replenish the reservoir with a third volume of separator material in a liquid state that is greater than the minimum volume of separator material.

[0058]

[0062] In this manner, the system 100 can track the volume of separator material exiting the spray nozzle during each coating segment of the processing cycle and replenish the volume of liquid separator material in the reservoir if the minimum volume of separator material exceeds the total volume of separator material exiting the spray nozzle.

[0059] 5.2 Drying Segment: First Solvent Removal + Phase Separation

[0063] During the second drying segment of the processing cycle, the system 100 can rapidly and simultaneously dry each separator material droplet in contact with the substrate. Additionally, the system 100 can heat the substrate and the separator material droplets to a temperature within a target temperature range proportional to the boiling point of the first solvent for a period of time. During the drying segment, the system 100 can also evaporate the first solvent from each separator material droplet, promoting phase separation between the second polymer (e.g., PEG) and the first polymer (e.g., PVDF-HFP) on the substrate.

[0060]

[0064] In one implementation, the system 100 can set time and temperature parameters for the drying segment of the processing cycle to control phase separation of the first polymer (e.g., PVDF-HFP) and the second polymer (e.g., PEG). In particular, in block S122, the system 100 can access a target substrate temperature range proportional to the boiling point of the first solvent (e.g., butanone). The system 100 can then heat the substrate and separator material droplets for a period of time (e.g., 10 seconds, 30 seconds) to evaporate the first solvent from the separator material in block S130. More specifically, the system 100 can access a target substrate temperature range, such as between 74°C and 79°C, between 77°C and 79°C, and / or between 78.9°C and 79.4°C. The system 100 can then begin the drying segment of the processing cycle and heat the separator material droplets and substrate to a temperature within the target substrate temperature range.

[0061]

[0065] For example, system 100 can spray coat separator material droplets onto a substrate during a coating segment of a processing cycle. In this example, each droplet in the separator material droplets includes a first solvent including a first volume of an organic ketone solvent (e.g., butanone), a first polymer that is miscible in the first volume of the organic ketone solvent and includes a second volume of a copolymer (e.g., PVDF-HFP), and a second polymer that is miscible in the first volume of the organic ketone solvent and includes a third volume of a polyether (e.g., PEG). The system 100 can then access a target substrate temperature below the boiling point of the organic ketone solvent (e.g., between 77 and 79 degrees Celsius) and begin the drying segment of the processing cycle, heating the substrate and separator material droplets via a heater coupled to the substrate to a temperature within the target substrate temperature range (e.g., 78 degrees Celsius) to evaporate the first volume of organic ketone solvent (e.g., butanone) from the separator material droplets and promote phase separation of the second polymer (e.g., PEG) from the first polymer (e.g., PVDF-HFP).

[0062]

[0066] However, the separator materials and substrate may be treated for other times and at other temperatures during the second drying segment of the treatment cycle.

[0063]

[0067] The system 100 can then transport the substrate to a washing assembly to wash or rinse the separator material droplets with a second solvent to dissolve the second polymer from the separator material droplets, thereby forming an open cell network of pores.

[0064] 5.3 Washing Segment: Removal of Second Polymer

[0068] During a third wash segment of the processing cycle, the system 100 can wash or rinse the separator material droplets with a chemical bath including a second solvent (e.g., alcohol) to dissolve the second polymer (e.g., PEG) out of the separator material droplets and form an open-cell network of pores. Further, the system 100 can wash the substrate and separator material droplets with the second solvent in block S140 to form an open-cell network of pores dispersed throughout the separator material droplets.

[0065]

[0069] In one implementation, system 100 can receive separator material droplets (each droplet including a first volume of a first polymer (e.g., PVDF-HFP) and a second volume of a second polymer (e.g., PEG)) and a substrate from a spray coating system at a washing station. Then, at the washing station, system 100 dissolves the second polymer (e.g., PEG) from the separator material droplets and washes the separator material droplets with a second solvent including a third volume of alcohol (e.g., isopropanol) to form an open-cell network of pores. This completely swells the substrate, dissolving the second polymer (e.g., PEG) from the pores of the separator material and creating open channels for ion transport through the separator material.

[0066]

[0070] In one variation, system 100 can perform a block of method S100 to rinse the separator material droplets and substrate with a second solvent (e.g., isopropanol) to form an open-cell network of pores, and then spray a stream of air onto the separator material droplets and substrate to remove excess isopropanol remaining from the chemical bath from the separator material droplets and substrate. For example, the substrate can be immersed in a heated bath of the second solvent (e.g., isopropanol), agitated for a period of time, removed from the bath, and dried to remove the second polymer (e.g., PEG) from the separator material.

[0067]

[0071] Additionally, the system 100 can transport the substrate to an irradiation station, which then irradiates the separator material droplets on the substrate, thereby promoting cross-linking of the first polymer (e.g., PVDF-HFP) and forming a separator membrane having an open-cell network of pores.

[0068] 5.4 Irradiation Segment: Thin Film

[0072] During a fourth irradiation segment of the processing cycle, system 100 can irradiate the separator material droplets and the substrate to crosslink the first polymer, forming a separator membrane (e.g., a discrete separator layer, a permeable separator membrane) on the substrate in block S150, the separator membrane having an open cell network of pores sized to allow ions to transport through the separator membrane. In particular, system 100 can selectively expose the substrate to the electron beam to further crosslink molecules in the first polymer (e.g., PVDF-HFP) and form the separator membrane.

[0069]

[0073] In one implementation, the irradiation station includes an electron beam configured to transport electrons toward the separator material droplets and the substrate, cross-linking molecules in the first polymer (e.g., PVDF-HFP) to form a polymer matrix, flash-drying residual solvent from the substrate, and forming a separator membrane on the substrate.

[0070]

[0074] In one variation, system 100 can receive a first substrate including a cathode at the irradiation station and then receive a second substrate including an anode from the cleaning station at the irradiation station. In this variation, system 100 can receive the cathode and anode from which the second polymer (e.g., PEG) has been removed from the separator material droplets and can transport electrons toward the cathode and anode via the electron beam to form a continuous non-conductive structure that extends beyond the perimeter of the cathode and extends beyond the perimeter of the anode.

[0071]

[0075] For example, system 100 can receive a first substrate including a cathode at an irradiation station and irradiate the separator material droplets and the cathode with an electron beam to crosslink the first polymer (e.g., PVDF-HFP) and form a continuous, non-conductive structure. This defines a separator membrane having an open-cell network of pores sized to transport ions through the separator membrane and extending beyond the periphery of the cathode. System 100 can then receive a second substrate including an anode at an irradiation station and irradiate the separator material droplets and the anode with an electron beam to crosslink molecules within the first polymer (e.g., PVDF-HFP) and form a continuous, non-conductive structure. Thus, during post-processing after assembly of the anode and cathode into a battery cell, the continuous, non-conductive structure can prevent electron flow between the anode and cathode, preventing electrical shorts within the battery cell.

[0072]

[0076] Additionally or alternatively, the system 100 can irradiate the separator material droplets and the cathode and / or anode via an electron beam to crosslink the first polymer and form a separator membrane on the cathode and / or anode, including a permeable separator membrane having an open cell network of pores sized to allow ions to transport through the permeable separator membrane.

[0073]

[0077] Thus, the system 100 can rapidly dry and clean the substrate, and then irradiate the separator material droplets to form a rigid, continuous, non-conductive structure of uniform thickness on the substrate, thereby forming a thin film of separator material exhibiting targeted mechanical, electrical, optical, and physical properties.

[0074] 6. Post-processing of Battery Assembly: Solvated Iontophoresis

[0078] In one variation, the separator membrane can form a porous electrolyte structure that extends beyond the perimeter of the substrate (e.g., cathode, anode) during the final irradiation segment of the processing cycle. System 100 can then expose the electrolyte structure to a solvent (e.g., organic solvent) and ions to fill the open-cell network of pores within the electrolyte structure with solvated ions, thereby forming an electrolyte. In this variation, system 100 can introduce solvated ions (e.g., lithium ions) into the electrolyte structure to fill the open-cell network of pores, thereby enabling the electrolyte structure to function as an ion-bearing (e.g., lithium-ion-bearing) electrolyte in a subsequently assembled battery cell for an electric vehicle or wearable device.

[0075]

[0079] Thus, system 100 can perform a processing cycle to form a porous electrolyte structure that extends beyond the perimeter of the anode or cathode, and then fill the open-cell network of pores with solvated ions to form the electrolyte. Additionally, the electrolyte can act as a buffer or electrode separator between the anode and cathode assembled into a battery cell to prevent the flow of electrons between the anode and cathode within the battery cell (i.e., to prevent electrical shorts).

[0076] 7. Variation: Parallel spray nozzle

[0080] In one variation, the coating delivery subsystem can include a set of spray nozzles coupled in parallel by a valve, each spray nozzle in the set of spray nozzles capable of simultaneously spray coating a separator material onto a substrate to achieve a separator film exhibiting a uniform target thickness across the substrate. In this variation, the valve can include a chemically resistant solenoid valve (resistant to the first solvent (e.g., butanone) in the polymer-polymer-solvent liquid mixture) operable between open and closed positions to maintain the vapor pressure of the polymer-polymer-solvent liquid mixture within each spray nozzle of the coating delivery subsystem.

[0077]

[0081] For example, the coating supply subsystem may include a set (e.g., three) spray nozzles connected in parallel by solenoid valves to define a coating zone and configured to simultaneously spray coat separator material onto substrates within the coating zone. At a first time, the system 100 may receive a first section of substrate tape including a first substrate within the coating zone, spray coat the first section of the first substrate with a first group of separator material droplets via the first spray nozzle, spray coat a second section of the first substrate with a second group of separator material droplets via the second spray nozzle, and spray coat a third section of the first substrate interposed between the first and second sections of the first substrate with a third group of separator material droplets via the third spray nozzle.

[0078]

[0082] At a second time subsequent to the first time, the system 100 performs the methods and techniques described above to heat the first substrate to a target substrate temperature, simultaneously and rapidly dry the first, second, and third separator material droplets on the first substrate to evaporate the first solvent (e.g., butanone) from the first, second, and third separator material droplets, wash the first, second, and third separator material droplets and the substrate with a second solvent (e.g., isopropanol) to dissolve the second polymer (e.g., PEG) from the first, second, and third separator material droplets to form an open-cell network of pores, and irradiate the first, second, and third separator material droplets with an electron beam to crosslink the first polymer (e.g., PVDF-HFP) and form a separator material film that extends beyond the periphery of the first substrate (e.g., wrapping around the entire surface of the first substrate). In this manner, each spray nozzle in the coating delivery subsystem can spray coat a corresponding portion of the substrate to achieve a uniform target thickness of the separator film.

[0079]

[0083] Additionally or alternatively, the coating delivery subsystem can include a set (e.g., three) of spray nozzles connected in parallel by solenoid valves to define a set (e.g., three) of coating zones configured to spray coat the separator material onto corresponding substrates in the series of substrates within each coating zone. In this variation, system 100 can batch process a series of substrates simultaneously during a processing cycle.

[0080]

[0084] For example, at a first time, the system 100 can receive a first section of a substrate tape including a first substrate in a first coating zone, a second section of a substrate tape including a second substrate in a second coating zone, and a third section of a substrate tape including a third substrate in a third coating zone. At approximately the first time, the system 100 can spray coat a first group of separator material droplets onto the first substrate via a first spray nozzle, a second group of separator material droplets onto the second substrate via a second spray nozzle, and a third group of separator material droplets onto the third substrate via a third spray nozzle. At a second time subsequent to the first time, the system 100 performs the methods and techniques described above to heat the first substrate, the second substrate, and the third substrate to a target substrate temperature, simultaneously and rapidly dry the first, second, and third separator material droplets on the first, second, and third substrates to evaporate the first solvent (e.g., butanone) from the first, second, and third separator material droplets, wash the first, second, and third separator material droplets and the first, second, and third substrates with a second solvent (e.g., isopropanol), and dry the first, second, and third separator material droplets. and dissolving a second polymer (e.g., PEG) from the first, second, and third separator material droplets to form an open-cell network of pores on the first, second, and third substrates, and irradiating the first, second, and third separator material droplets with an electron beam to crosslink the first polymer (e.g., PVDF-HFP) to form a first separator material film extending beyond the perimeter of the first substrate (e.g., wrapping around the entire surface of the first substrate), a second separator material film extending beyond the perimeter of the second substrate, and a third separator material film extending beyond the perimeter of the third substrate. In this manner, each spray nozzle of the coating delivery subsystem can spray coat a corresponding substrate in the series of substrates to achieve a separator material film of a uniform target thickness on the series of substrates in a batch coating process.

[0081] 8.Other separator material applications

[0085] Generally, the method S100 described above involves fabricating a separator membrane of uniform thickness on a planar anode, followed by assembly of a planar cathode on the separator membrane, to produce a rigid separator membrane suitable for use in 2D or 3D lithium-ion batteries for electric vehicles. However, similar methods and techniques can be used to fabricate a rigid, conformable separator membrane for fabricating 3D batteries on silicon wafers. Similarly, these methods, techniques, and materials can be used to fabricate 2D or 3D hydrogen fuel cells containing separator membranes that define a controlled density and distribution of relatively large pores that enable improved hydrogen ion conduction through the fuel cell. Furthermore, these methods, techniques, and materials can be used to fabricate 2D or 3D nickel-metal hydride batteries containing separator membranes that define a controlled density and distribution of relatively large pores that enable improved hydrogen ion conduction through the nickel-metal hydride battery.

[0082]

[0086] However, the separator material can be applied and processed in other ways to form a conformable, rigid separator membrane. Similarly, method S100 can be performed in any other way to create a conformable, rigid separator membrane, either directly on an electrode or separate from an electrode.

[0083]

[0087] The system 100 and methods described herein may be embodied and / or implemented, at least in part, as a machine configured to receive a computer-readable medium storing computer-readable instructions. These instructions are executed by a computer-executable component integrated with an application, applet, host, server, network, website, communication service, communication interface, hardware / firmware / software element of a user computer or mobile device, wristband, smartphone, or any suitable combination thereof. Other system 100 and methods of embodiments may be embodied and / or implemented, at least in part, as a machine configured to receive a computer-readable medium storing computer-readable instructions. The instructions are executed by a computer-executable component integrated with a device or network of the above-mentioned types. The computer-readable medium may be stored in any suitable computer-readable medium, such as RAM, ROM, flash memory, EEPROM, optical device (CD or DVD), hard drive, floppy drive, or any suitable device. The computer-executable component may be a processor, although any suitable dedicated hardware device may (alternatively or additionally) execute the instructions.

[0084]

[0088] Those skilled in the art will recognize from the foregoing detailed description, and from the figures and claims that modifications and variations can be made to the embodiments of the present invention without departing from the scope of the invention as defined in the following claims.

Claims

1. 1. A method for depositing a separator material, comprising: During the first period, receiving a first section of substrate tape comprising a first substrate within a coating zone; spray-coating separator material droplets onto the first substrate, each droplet of the separator material droplets comprising a first solvent, a first polymer miscible in the first solvent, and a second polymer miscible in the first solvent; accessing a target substrate temperature below the boiling point of the first solvent; During a second period following the first period, heating the first substrate and the separator material droplets to a target substrate temperature to evaporate a first solvent from the separator material droplets and promote phase separation of the second polymer from the first polymer; washing the separator material droplets with a second solvent to dissolve the second polymer from the separator material droplets and form an open-cell network of pores within the separator material droplets; irradiating the separator material droplets and the first substrate to crosslink the first polymer and form a separator membrane on the first substrate, the separator membrane defining an open cell network of pores sized to transport ions; During a third period following the first period, receiving a second section of substrate tape comprising a second substrate within the coating zone; spray-coating droplets of a second separator material onto the second substrate, each droplet of the second separator material droplets comprising the first solvent, a first polymer miscible in the first solvent, and a second polymer miscible in the first solvent; During a fourth period following the third period, heating the second substrate and the second separator material droplets to a target substrate temperature to evaporate the first solvent from the second separator material droplets and promote phase separation of the second polymer from the first polymer; washing the separator material droplets with a second solvent to dissolve the second polymer from the second separator material droplets and form an open-cell network of pores within the second separator material droplets; irradiating the second separator material droplets and the second substrate to crosslink the first polymer and form a second separator film on the second substrate that is continuous with the separator film on the first substrate; A method comprising:

2. 10. The method of claim 1, Further, during the first period, defining a target gas temperature range for the first solvent, the target gas temperature range corresponding to a target vapor pressure of a separator material in a gaseous environment; in a vessel containing a gaseous environment of the first solvent above a reservoir of separator material in a liquid state, heating the gaseous environment toward the target gas temperature range; and detecting a second temperature of the gaseous environment; the step of spray-coating separator material droplets onto the first substrate comprises spray-coating separator material droplets onto the first substrate in response to a second temperature of the separator material falling within the target gas temperature range.

3. 10. The method of claim 1, Further, during the first period, defining a target liquidus temperature range for a separator material; a spray nozzle connected to a reservoir of separator material in a liquid state and facing the first substrate; heating the spray nozzle to the target liquid temperature range; and detecting a second temperature of the separator material at the spray nozzle; the step of spray-coating separator material droplets onto the first substrate includes spray-coating the separator material droplets onto the first substrate through the spray nozzle in response to the second temperature falling within the target liquid temperature range.

4. 4. The method of claim 3, Further, during the first period, receiving a target separator thickness for the separator membrane; selecting a target offset distance between the spray nozzle and a first substrate based on the target separator thickness; detecting a first distance between the spray nozzle and the first substrate within the coating zone; adjusting the first distance to the target offset distance between the spray nozzle and the first substrate in response to the target offset distance exceeding the first distance between the spray nozzle and the first substrate; the step of spray-coating separator material droplets onto the first substrate includes spray-coating separator material droplets onto the first substrate through the spray nozzle at the target offset distance; the step of irradiating the separator material droplets and the first substrate includes irradiating the separator material droplets and the first substrate to crosslink the first polymer and form a separator film exhibiting a separator thickness approximating the target separator thickness.

5. 10. The method of claim 1, the step of receiving a first substrate includes receiving a first substrate that constitutes a cathode within the coating zone; the step of spray-coating separator material droplets onto the first substrate includes spray-coating the separator material droplets onto the cathode; the step of irradiating the separator material droplets and the first substrate includes irradiating the separator material droplets and the cathode with an electron beam to crosslink the first polymer and form a continuous, non-conductive structure; the non-conductive structure defining a separator membrane having an open cell network of pores sized to allow ion transport through the separator membrane; extending beyond the periphery of the cathode.

6. 10. The method of claim 1, the step of receiving a first substrate includes receiving a first substrate that constitutes an anode within the coating zone; the step of spray-coating separator material droplets onto the first substrate includes spray-coating the separator material droplets onto the anode; the step of irradiating the separator material droplets and the first substrate includes irradiating the separator material droplets and the anode with an electron beam to crosslink the first polymer and form a continuous, non-conductive structure; the non-conductive structure defining a separator membrane having an open cell network of pores sized to allow ion transport through the separator membrane; extending beyond the periphery of the anode.

7. 10. The method of claim 1, further comprising the step of defining a target separator thickness corresponding to a target conductivity of the separator film during the first period of time; the step of irradiating the separator material droplets and the first substrate to crosslink the first polymer and form a separator membrane includes irradiating the separator material droplets and the first substrate to crosslink the first polymer and form a separator membrane having a separator thickness approximating the target separator thickness.

8. 10. The method of claim 1, further comprising receiving a target separator thickness for the separator membrane during the first period; the step of spray-coating the separator material droplets includes spray-coating the separator material droplets onto the first substrate using a first spray nozzle connected to a reservoir of separator material in a liquid state and facing the first substrate; further, during the second period of time, spray coating a second group of separator material droplets onto the first substrate with a second spray nozzle connected to a reservoir of the separator material, each droplet in the second group of separator material droplets including the first solvent, the first polymer, and the second polymer; the step of irradiating the separator material droplets and the first substrate to crosslink the first polymer and form a separator membrane includes irradiating the separator material droplets, the second separator material droplets, and the first substrate to crosslink the first polymer and form a separator membrane having a separator thickness approximating the target separator thickness.

9. 10. The method of claim 1, The step of spray-coating separator material droplets onto the first substrate includes spray-coating separator material droplets onto the first substrate, each droplet of the separator material droplets comprising: a first solvent comprising a first volume of an organic ketone solvent; a first polymer that is miscible in the first volume of organic ketone solvent and comprises a second volume of a copolymer; a second polymer that is miscible in the first volume of organic ketone solvent and that comprises a third volume of a polyether; accessing the target substrate temperature includes accessing a target substrate temperature that is less than a boiling point of the organic ketone solvent; wherein heating the first substrate and the separator material droplets to a target substrate temperature to evaporate the first solvent comprises heating the first substrate and the separator material droplets to a target substrate temperature to melt the first volume of organic ketone solvent out of the separator material droplets and promote phase separation of a second polymer from the first polymer.

10. 10. The method of claim 9, wherein washing the separator material droplets with a second solvent comprises washing the separator material droplets with a second solvent comprising a fourth volume of alcohol to dissolve a third volume of polyether from the separator material droplets and create an open-cell network of pores within the separator material droplets.

11. 10. The method of claim 1, wherein the step of spray coating separator material droplets onto the first substrate comprises spray coating separator material droplets onto the first substrate, each droplet of the separator material droplets comprising molecules of a first polymer defining a minor cross-sectional width, the minor cross-sectional width being: Larger than the minimum cross-sectional width of a lithium ion, and The method wherein the minimum cross-sectional width is less than the substrate thickness.

12. 10. The method of claim 1, wherein irradiating the separator material droplets and the first substrate comprises irradiating the separator material droplets and the first substrate with an electron beam to crosslink the first polymer and form a separator membrane on the first substrate comprising a permeable separator membrane having an open cell network of pores sized to allow ions to transport therethrough.

13. 2. The method of claim 1, wherein the step of dissolving the second polymer from the separator material droplets comprises: rinsing the separator material droplets and the first substrate with a second solvent to form an open-cell network of pores; and spraying a stream of air onto the separator material droplets and the first substrate to remove the second solvent from the separator material droplets and the first substrate.

14. 10. The method of claim 1, wherein the step of spray-coating separator material droplets onto the first substrate comprises spray-coating separator material droplets onto the first substrate, each droplet of the separator material droplets comprising 15% to 20% by weight of a first solvent comprising an organic ketone.

15. 1. A method for depositing a separator material, comprising: During the first period, receiving a first section of substrate tape comprising a first substrate within a coating zone; defining a target liquidus temperature range for a separator material; a spray nozzle facing the first substrate and connected to a reservoir of separator material in a liquid state, heating the spray nozzle to the target liquid temperature range; sensing a first temperature of the separator material at the spray nozzle; responsive to a first temperature of the separator material being within the target liquid temperature range, spray coating a volume of a first separator material, the first separator material including a first solvent, a first polymer miscible in the first solvent, and a second polymer miscible in the first solvent, onto the first substrate through the spray nozzle; accessing a target substrate temperature below the boiling point of the first solvent; During a second period following the first period, heating the first substrate and the volume of first separator material to a target substrate temperature to evaporate the first solvent from the volume of first separator material; dissolving the second polymer from a volume of the first separator material to form an open-cell network of pores; irradiating a volume of the first separator material to crosslink the first polymer and form a first separator membrane having a separator thickness approximating a target separator thickness and extending beyond a first perimeter of the first substrate; During a third period following the first period, receiving a second section of substrate tape comprising a second substrate within the coating zone; sensing a second temperature of the separator material at the spray nozzle; responsive to a second temperature of the separator material being within the target liquid temperature range, spray coating a volume of a second separator material onto the second substrate through the spray nozzle, the second separator material comprising a first solvent, a first polymer miscible in the first solvent, and a second polymer miscible in the first solvent; During a fourth period following the third period, heating the second substrate and the volume of second separator material to a target substrate temperature to evaporate the first solvent from the volume of second separator material; dissolving the second polymer from a volume of the first separator material to form an open-cell network of pores; irradiating a volume of the second separator material to crosslink the first polymer and form a second separator film having a separator thickness approximating a target separator thickness, extending beyond a second perimeter of the second substrate, and continuous with the first separator film on the first substrate; A method comprising:

16. 16. The method of claim 15, Further, during the first period, defining a target gas temperature range for the separator material, the target gas temperature corresponding to a target vapor pressure of the separator material in a gaseous state; in a vessel containing a gaseous environment above a reservoir of separator material in a liquid state, heating the gaseous environment toward the target gas temperature range; and detecting a second temperature of the gaseous environment; the step of spray-coating the volume of separator material onto the first substrate includes spray-coating the volume of first separator material onto the first substrate through the spray nozzle in response to a first temperature of the separator material falling within a target liquid temperature range and in response to a second temperature of the separator material falling within the target gas temperature range.

17. 16. The method of claim 15 further comprising: detecting a minimum volume of separator material in a liquid state in the reservoir during the first period of time; During the third period following the first period, calculating a total volume of separator material on the first substrate and the second substrate based on a combination of the volume of the first separator material and the volume of the second separator material; and in response to the total volume of the separator material exceeding a minimum volume of the separator material, refilling the reservoir with a volume of a third separator material in a liquid state that is greater than the minimum volume of the separator material.

18. 1. A method for depositing a separator material, comprising: During the first period, receiving a portion of a substrate tape including a first substrate in a coating zone; depositing separator material droplets onto the first substrate, each droplet of the separator material droplets comprising a first solvent, a first polymer, and a second polymer; During a second period following the first period, heating the first substrate and the separator material droplets to a first temperature to evaporate the first solvent from the separator material droplets; washing the separator material droplets and the first substrate with a second solvent to dissolve the second polymer from the separator material droplets and form an open-cell network of pores within the separator material droplets; irradiating the separator material droplets to crosslink the first polymer and form a discrete separator layer on the first substrate, the discrete separator layer defining an open cell network of pores sized to transport ions; During a third period following the first period, receiving a second section of substrate tape comprising a second substrate within the coating zone; depositing droplets of a second separator material onto the second substrate, each droplet of the second separator material droplets comprising the first solvent, the first polymer, and the second polymer; During a fourth period following the third period, heating the second substrate and the second separator material droplets to the first temperature to evaporate the first solvent from the second separator material droplets; washing the second separator material droplets and the second substrate with a second solvent to dissolve the second polymer from the second separator material droplets and form an open-cell network of pores within the second separator material droplets; irradiating the second separator material droplets to crosslink the first polymer and form a second discrete separator layer on the second substrate, the second discrete separator layer defining an open cell network of pores sized to transport ions; A method comprising:

19. 20. The method of claim 18, wherein depositing separator material droplets on the first substrate comprises spray-coating monodisperse separator material droplets onto the first substrate, each droplet of the separator material droplets being sized to prevent defect formation in a discrete separator layer on the first substrate.

Images