Patent ID: 12188140

DETAILED DESCRIPTION

Various apparatuses or processes will be described below to provide an example of an embodiment of each claimed invention. No embodiment described below limits any claimed invention and any claimed invention may cover processes or apparatuses that differ from those described below. The claimed inventions are not limited to apparatuses or processes having all of the features of any one apparatus or process described below or to features common to multiple or all of the apparatuses described below. It is possible that an apparatus or process described below is not an embodiment of any claimed invention. Any invention disclosed in an apparatus or process described below that is not claimed in this document may be the subject matter of another protective instrument, for example, a continuing patent application, and the applicants, inventors, or owners do not intend to abandon, disclaim, or dedicate to the public any such invention by its disclosure in this document.

Referring toFIG.1, a schematic representation of one example of an electrorefining cell100that is configured to refine relatively purer lithium metal from a lithium-alloy feedstock material is illustrated. In this example the cell100includes housing112that defines an interior chamber that is configured to retain the materials described herein and can be formed in any suitable shape or configuration. In this example, the cell100can be described as a three-layer cell as it is configured to accommodate a lower, anode layer102that includes a liquid feedstock material (in the form of the lithium-alloy feedstock material in this example), an intermediate, electrolyte layer104including a suitable liquid electrolyte material as described herein, and an upper, product layer106that contains a seed amount of the refined metal product when the cell100is started and in which, when an activation electric potential that is sufficient to electrolyze the lithium-alloy feedstock material is applied within the cell100(as described herein), lithium metal that is liberated from the lithium-alloy feedstock material can collect after it, migrates through the electrolyte layer104.

In this schematic example, the cell100is configured as an elongate, conduit-like apparatus that is configured as a flow-through apparatus (i.e. the material in layers102and optionally104are flowing while the cell100is in use). In such arrangements, the cell100is preferably oriented generally sideways and arranged to be generally level, such that the free surfaces of the lower layer102and intermediate layer104are substantially flat and horizontal when the cell is in use100(as illustrated). This can help prevent unwanted flow characteristics, reaction properties and/or mixing between the layers.

To help facilitate the desired electrorefining process/reaction, the cell100includes at least one suitable anode conductor member120that is electrically connected to a suitable power source via connection122, and a corresponding cathode conducting member as described below. The anode conductor member120is positioned to apply a charge to the lithium-alloy feedstock material in the lower layer102. The anode conductor member120may optionally, include an electrical conductor that is located within the interior chamber bounded by the housing112and is at least partially submerged in or otherwise in electrical contact with the lower layer102(such as conductor120ain this schematic example). In other examples described herein, a sidewall or other suitable portion of the housing112itself that is in sufficient electrical contact with the lower, anode layer102may itself be electrically conductive and may be configured to function as a suitable anode. Optionally, if the feedstock material is electrically conductive it may act as the anode, and may be partially consumed, while the cell100is in use. The anode conductor member120(whether free standing or integrated into the housing sidewall) can be formed from any suitably electrically conductive material, and is preferably formed from the cathode is a material that is not wettable by, or is generally non-reactive with, the lithium metal, or may be made from stainless steel.

Similarly, the cell100includes at least one suitable cathode conducting member124that is located toward the top of the housing112, connected to a suitable power source via connection126and can be in contact with the electrolyte and the refined lithium metal in the upper layer106when the cell100is in use. The cathode conducting member124is arranged as to be electrically isolated from the anode conductor member120and anode layer102and to apply its charge to an initial seed of the relatively purer lithium metal in the product layer106, and to the rest of the lithium metal that accumulates in the product layer106while the cell100is in use, whereby the refined lithium in the product layer106(and the product layer106itself) functions as the cathode. In this arrangement, when the cell100is in use, and a suitable, activation electric potential is applied between the anode layer102and product layer106(e.g. an electric potential that is sufficient to electrolyze the lithium-alloy feedstock material) lithium metal is liberated/stripped from the feedstock material, can migrate upwardly through the electrolyte in the intermediate, electrolyte layer104and can then collects in the upper, refined metal layer106(proximate the cathode conducting member124) where it can be extracted from the cell100using any suitable refined metal extraction system.

In the illustrated example, the refined metal extraction system includes a refined metal extraction conduit128having an inlet end130that is located inside the housing112and in fluid communication with the refined metal-containing, upper, product layer106In the illustrated example the refined lithium metal may by at least partially driven thorough the refined metal extraction conduit128via the hydrostatic pressure within the housing112. Optionally, the refined metal extraction conduit128can also be connected to any suitable vacuum or flow control apparatus to help motivate the flow of the refined metal, and a suitable refined metal collection or storage vessel.

Preferably, the exposure of the refined lithium metal to oxygen or other potential contaminants while it is in the product layer106can be inhibited or minimized, which may help prevent the unwanted reactions. Optionally, the cell100can include a gas headspace107that is defined as the space within the interior chamber that is above the product layer106and is in communication with the exposed, free surface of the product layer106. The gas headspace107preferably contains a cover gas that is preferably substantially free from oxygen, carbon dioxide, nitrogen and water vapour to inhibit oxidation, carbonation, hydration and nitration of the lithium metal in the product layer. The cover gas could be any suitable gas or mixture of gases including argon, helium, a fluorocarbon gas and a hydrocarbon gas that comprises at least one of propane, butane, hexane, and mixtures thereof and other relatively inert gases that will not react with the refined lithium under the conditions that are expected within the cell100.

Optionally, the cover gas can be circulated and/or flowing through or within the gas headspace107while the cell100is in use. The cover gas may be fed through the cell100at any suitable gas flow rate, which may be, in some examples between 10-20 scfm.

Optionally, as described in this example, the cell100can be configured as a flow-through cell, in which at least one of the feedstock and the electrolyte, and preferably both the feedstock and the electrolyte materials are provided in a liquid/molten form such that they can and do flow through the cell100(within their respective layers102and104) while it is in use (as compared to a static or batch type of process where both the feedstock and the electrolyte are not flowing while the apparatus is in use—for example seeFIGS.9-11). This may allow the cell100to be used in an online or real-time basis and in combination with an online or ongoing lithium production process that produces a generally continuous stream/flow of the unrefined lithium metal and lithium-alloy feedstock material. Preferably, the cell100is operated so that the liquids flow through the cell100with relatively slow velocities/mass flow rates and under generally laminar flow conditions, which may help reduce turbulence or mixing between the layers102,104and106while the cell is in use. The flow rates of the feedstock alloy and the electrolyte material (such as a molten salt) can be different from each other, or may be the same.

Preferably, to help maintain the desired 3-layer arrangement, the wherein the lithium-alloy feedstock material is created so that it has a density that is greater than the density of the electrolyte material in layer104, and preferably can be greater than 1.6 g/cm3, and optionally may be equal to or greater than 2.15 g/cm3. Similarly, it can be preferred that the electrolyte material has a density that is less than the density of lithium-alloy feedstock material (so that it will generally float on anode layer102) and is greater than the density of the refined lithium metal, e.g. greater than about 0.6 g/cm3, so that the product layer106will float on the electrolyte layer104.

To help accommodate the desired material flows in this schematic illustration, the cell100includes a feedstock inlet108at one end of the housing112and a feedstock outlet110that is spaced apart from the feedstock inlet108in a first, feedstock flow direction (shown by arrow114). In the illustrated schematic the feedstock outlet110is at the opposing end of the housing112, but could be in other suitable locations in other examples of an electrorefining cell. Preferably, the feedstock inlet108and outlet110are located in a lower portion of the housing112and are positioned to be in communication with the anode layer102while the cell100is in use. The specific height and position of the feedstock inlet108and outlet110may vary in different cell configurations.

The feedstock inlet108and outlet110can include any suitable flow control mechanisms, such as valves, orifices, nozzles and the like to help control and direct the flow of the feedstock material as desired. The feedstock inlet108is preferably fluidly connected to a suitable source of the feedstock material that is to be refined, such as feedstock reservoir, and the feedstock outlet110is preferably connected to a suitable sink/storage location for receiving the reacted (and relatively lithium-poor because the lithium has migrated to the product layer106) lithium-depleted alloy material that exits the cell100when in use. One or both of the feedstock source and the feedstock sink may include a suitable tank or vessel that is connected to the cell100using any suitable pipes, conduits and the like. Optionally, the feedstock source and the feedstock sink may be combined together in a common reservoir vessel, such that the reacted, lithium-depleted alloy material exiting the cell100returns to the reservoir vessel and mixes with new, unreacted relatively lithium-rich feedstock liquid and/or additional crude lithium metal feed material can be added into the reservoir vessel to increase the lithium content of the lithium-alloy feedstock within the reservoir vessel. Then, some of that lithium-alloy feedstock material can be withdrawn from the reservoir vessel and fed back into the cell via inlet108. Preferably, the cell100can be connected to a suitable feedstock alloy reservoir or source/sink vessel via a feedstock circulation system that can also include any suitable conduits, pumps, flow control mechanisms, system controllers and the like.

The molten, lithium-alloy feedstock material that is supplied to the cell100and that forms the anode layer102can be of any suitable alloy composition that includes the target metal that is to be refined (e.g. lithium in these examples) along with one or more suitable carrier metal. In this example, the cell100is configured to refine lithium metal and incoming feedstock liquid is a molten, lithium-rich, metallic alloy liquid that contains crude lithium metal at a first purity alloyed with a carrier material that includes one or more suitable base or carrier metal. Some examples of suitable carrier metals that can be used in the feedstock alloy include lead, bismuth, tin, zinc, indium, thallium, gallium, copper, iron, etc. and their alloys. The purity of the crude lithium metal that is added to the feedstock material can preferably be about 80-99.9 at %, but may be lower than 80 at % in some examples. In addition to the relative purity of the incoming crude lithium metal, the lithium-alloy feedstock is also preferably prepared so that the concentration of lithium metal within the feedstock alloy may be between about 1 at % and about 80 at %, and preferably is less than about 80 at % because higher lithium content may alter some of the properties of the resulting lithium-alloy feedstock material in undesirable ways. This is understood to be the concentration of lithium metal in the overall lithium-alloy feedstock material, and does not include the contaminants or other non-lithium components of the incoming crude lithium metal material.

The applicant has tested various different compositions of the lithium-alloy feedstock material and has determined that a lithium-alloy feedstock material that includes a combination of lithium and at least at least two of bismuth, indium and tin can give some relatively desirable properties, and preferably the lithium-alloy feedstock material can be created to include a combination of lithium, bismuth, indium and tin. Optionally, in this arrangement the concentration of bismuth within the carrier material can be between 0 wt %-80 wt %, and optionally may be between 30 wt %-60 wt %, the concentration of indium metal within the carrier material can be between 0 wt %-80 wt %, and optionally may be between 22 wt %-60 wt %, and the concentration of tin within the carrier material can be between 0 wt %-80 wt %, and optionally may be between 10 wt %-60 wt %. These compositions have been tested and found to provide a lithium-alloy feedstock material having a relatively low melting point. Preferably, the lithium-alloy feedstock material is created so that it has a melting temperature that is less than 600 degrees Celsius, and optionally can be less than 580, 560, 550, 525, 500, 480, 460, 450, 420 degrees Celsius. In some configurations, the melting temperature of the lithium-alloy feedstock material is between 100-1000 degrees Celsius, or between 200-800 or 400-600 degrees Celsius, and may be between about 420-550 degrees Celsius. In some examples, the melting temperature can be less than 600 degrees Celsius. In these examples, the operating temperature of the cell100can be reduced to a level that is equal to, or preferably at least slightly greater than these melting temperatures, which may help reduce the energy consumption of the cell100.

To help accommodate the desired electrolyte flows, the cell100includes an electrolyte inlet132at one end of the housing112and a feedstock outlet134that is spaced apart from the feedstock inlet132in a feedstock flow direction (shown by arrow136). In the illustrated schematic the electrolyte inlet132is at the same end of the housing112as the feedstock inlet108, and the electrolyte outlet134is located at the same end of the housing112as the feedstock outlet110, such that the cell100is configured in a co-flow arrangement. In other examples, the inlets and outlets may be in different locations, and the cell100may be arranged in a counter-flow arrangement (e.g. where flows114and136are in opposite directions). In yet further embodiments, at least one of the layers102and104(and optionally both of the layers102and104) need not be flowing and may be relatively static while the cell is in use, such that the cell100is operated in a batch manner instead of a flow-through manner.

Preferably, the electrolyte inlet132and outlet134are located at a higher elevation than the feedstock inlet108and outlet and are positioned to be in communication with the electrolyte layer104while the cell100is in use. The specific height and position of the electrolyte inlet132and outlet134may vary in different cell configurations.

The electrolyte inlet132and outlet134can include any suitable flow control mechanisms, such as valves, orifices, nozzles and the like to help control and direct the flow of the feedstock material as desired. The electrolyte inlet132is preferably fluidly connected to a suitable source of the electrolyte, and the electrolyte outlet134is preferably connected to a suitable sink/storage location for receiving the electrolyte material that exits the cell100when in use. One or both of the electrolyte source and the electrolyte sink may include a suitable tank or vessel that is connected to the cell100using any suitable pipes, conduits and the like. Optionally, the electrolyte source and the electrolyte sink may be combined together in a common vessel, such that the electrolyte exiting the cell100returns to the vessel in a generally closed loop arrangement, while also being configured to allow for the addition of new electrolyte material into the system as needed. Preferably, the cell100can be connected to a suitable electrolyte source/sink vessel via an electrolyte circulation system that can also include any suitable conduits, pumps, flow control mechanisms, system controllers and the like.

The electrolyte material that is used to provide the electrolyte layer104can be any suitable material, and in the examples described herein is a molten salt that is flowable through the cell100, if desired, and can include chloride, fluoride, iodide, bromide, sulphate, nitrate and carbonate salts, and mixtures thereof and similar salts of other metals to produce a relatively low-melting point lithium ion containing melt, such as for example LiCl—KCl, LiI—CsI or LiI—KI. Optionally, the electrolyte material may include at least one of, or a mixture of LiCl—KCl, LII-KI and LiI—CsI. In some examples, electrolyte material may be a eutectic mixture of LiCl—KCl, LII-KI and LiI—CsI, in which the concentrations are between 46% LiCl-54% KCl (by weight), 58.5% LII-41.5% KI (by weight) and 45.7% LiI-54.3% CsI (by weight).

When the cell100is in use, the relatively lithium-rich, lithium-alloy feedstock material is introduced into the cell100via the feedstock inlet108to provide the anode layer102, and the molten salt electrolyte is introduced via the electrolyte inlet132to provide the electrolyte layer104. An electric potential is applied across the anode layer102and cathode (e.g. the cathode conducting member124and the charged lithium metal in the product layer106) whereby lithium metal is liberated from the feedstock material, migrates thorough the electrolyte layer104and collects toward the top of the housing112to provide the refined metal, product layer106. The product layer106is seeded with a portion of relatively pure lithium metal at the start of the process. The feedstock material can exit via feedstock outlet110as a relatively lithium-depleted/lithium-lean alloy material, the electrolyte can be withdrawn via electrolyte outlet134and at least some of the refined lithium metal can be extracted from the refined layer106. The refined lithium metal in the refined layer106can be at a second purity that is greater that the first purity of the lithium metal in the alloyed feedstock material, and preferably greater than 80%, 85%, 90%, 95% 98%, 99%, 99.9%, 99.99% pure and may be about 99.995% or higher purity in some examples.

One advantage of electrorefining using the electrorefining apparatuses and processes described herein may be that the cell100can be operated relatively low power consumption than alternatives, such as distillation. In the illustrated examples, the electrorefining cell100can be configured to operate at electropotentials of between about 0V and about 3.6V, or between about 0.6 and about 1.0V, which may allow operations with electrorefining power consumption less than 6 kW/kg metal produced. The cell100can be operated at any suitable current density, such as a current density between the anode layer and the cathode is between about 0.001 or 100 A/cm2, or between about 0.05 or 1.5 A/cm2, or between about 0.15-0.75 A/cm2and optionally can be configured to operate at a current density of at least 0.25 A/cm2.

When operated as described herein, the interior of the electrorefining cell100is preferably at a suitable operating temperature that is at least greater than the melting points of the feedstock alloy, refined metal layer and the electrolyte. In some examples the operating temperature can be above 180, 200, 220, 240, 250, 270, 280, 300, 320, 340, 350, 360, 380, 400, 420, 440, 460, 480, 500, 600 degrees Celsius or more and may be less than about 700, 650, 600, 550, 500, 480, 460, 440, 420 degrees Celsius in some preferred examples.

Referring toFIG.2, the cell100is schematically illustrated in combination with other components of an electrorefining apparatus, including a feedstock supply system140and an electrolyte supply system142. In this example, the feedstock supply system140includes the feedstock inlet108and outlet110, along with a suitable storage vessel/reservoir144and a feedstock circulation circuit146that includes a suitable pumping system148and other flow control features (not shown). In this arrangement, new, relatively less pure crude lithium metal that is to be refined can be added into the vessel144along with the alloying carrier metal material and these components may be mixed and heated within the vessel144. Heating the materials in the reservoir vessel144may reduce the amount of heating that is required inside the interior chamber of the housing112. Alternatively, the feedstock supply system140can include additional vessels for premixing the feedstock material before it is introduced within the vessel144.

Optionally, the level of the feedstock material within the vessel144, and/or the relative elevation of the vessel144relative to the housing112can be varied to change the hydrostatic pressure in the feedstock supply system140, which may affect the pressure and level of the anode layer102within the cell100. While illustrated as a single vessel144, a suitable reservoir may include two or more tanks could be used (for example one for supplying the feedstock material and one for receiving material from the cell) with a pump or other suitable systems for balancing the pressures and flows of material therebetween.

This schematic representation of the electrolyte supply system142includes the electrolyte inlet132and outlet134, along with an electrolyte source/sink vessel150and an electrolyte circulation circuit152that includes a suitable pumping system154and other flow control features (not shown)

While a single cell100is shown for simplicity inFIG.2, an electrorefining system may include two or more such cells. The multiple cells100may also be provided with separate feedstock supply systems140and electrolyte supply systems142, or alternatively two or more cells100may be connected to a common feedstock supply system140and/or electrolyte supply system142—preferably in parallel with each other, but optionally in series.

Referring toFIG.3, another example of an electrorefining cell1100is illustrated. The cell1100is generally analogous to the cell100and like features are indicated using like reference characters indexed by 1000. In this example, the cell1110includes an anode layer1102, having a respective feedstock inlet1108and feedstock outlet1110, a refined metal or product layer1106and a layer of molten salt electrolyte in the electrolyte layer1104positioned therebetween, with a respective electrolyte inlet1132and electrolyte outlet1134. In this example, instead of a separate member that is submerged within the anode layer1102the anode conductor member1120in the cell1100is provided by a conductive portion1158of the housing1112that is connected to a power source via the connection1122and in electrical contact with the metallic anode layer1102, but that is electrically isolated from the cathode conducting member1124. The isolated, anode portion1158of the housing can be electrically isolated from the cathode conducting member1124using an electrically insulating/isolating assembly1160that can include gaskets or other mounting structures, such as an axially extending insulator1160ashown schematically inFIG.3. This may help simplify construction of the cell1100, and may help facilitate a desired flow of the metallic feedstock alloy in layer1102as a separate anode conductor member structure need nor protrude into the layer1102which might impede or disrupt the flow of the molten lithium-alloy feedstock of induce turbulence.

To help maintain the lithium-alloy feedstock and the electrolyte materials at the desired operating temperature, the apparatuses described herein can include any suitable type of heater that can be used to help keep the interior chamber at an operating temperature that is higher than the a freezing temperature of the lithium-alloy feedstock material, the molten salt electrolyte material and the lithium metal.

Optionally, a suitable heater can include a heating element in contact with an outer surface of the housing, such as contact heating element1125that is schematically illustrated inFIG.3. Alternatively, or in addition to a housing heater like1125, the system could include one or more inline heaters having heating elements that can heat the flows of the feedstock and electrolyte while they are outside of the interior chamber of the cell—such as the heaters127illustrated schematically inFIG.2. Each of these heating elements, can include resistive heaters, heat exchanger coils and any other suitable heating mechanism.

Alternatively, or in addition to the heaters127or1125, the heater used with the apparatus can be an external heating device that does not need to be in direct contact with the cell or the flowing materials. One example of such a device is a furnace chamber or other environment that is sized to contain the entirety of the cell, and optionally the feedstock and/or electrolyte material reservoirs and at least portions of the supply and recycle conduits. The interior of the furnace chamber can be heated to a temperature that is equal to, or preferably is slightly greater than the desired operating temperature of the cell. This ambient, environmental heating can heat the cell and its contents without exposing the heating elements to direct contact with the electrolyte or lithium metal, which may help reduce damage to the heating elements. Examples of such surrounding, furnace chambers are shown schematically as chambers155and1155inFIGS.2and3respectively. The chambers155and1155are shown in dashed lines to indicate they are optional features of these examples.

As shown inFIG.2, the chamber155is configured to contain the cell100, along with the reservoir vessels144and150and other portions of the material flow circuits.FIG.3shows another example, where chamber1155is configured to contain the cell1100. The other cells described herein (including cells2100,3100,4100and5100) may be placed within correspondingly configured furnace chambers to help keep the cells2100,3100,4100and5100and their contents at or above the desired operating temperatures without requiring direct contact heating elements on the housings or other exterior portions of the cells where they are prone to damage.

Referring toFIGS.4to6, another example of an electrorefining cell2100is illustrated. The cell2100is generally analogous to the cell100and like features are indicated using like reference characters indexed by 2000. In this example, the cell2100includes an anode layer2102, having a respective feedstock inlet2108and feedstock outlet2110, a refined metal layer2106and a layer of molten salt electrolyte2104positioned therebetween, with a respective electrolyte inlet2132and electrolyte outlet2134. InFIG.5athe layers2102,2104and2106are identified using different cross-hatching that extends only part way across the cell2100so that the underlying structure is also visible in part of the drawing. This partial extension of the layers2102,2104and2106is for illustrative clarity only, and in operation the layers2102,2104and2106would extend the length of the housing2112, between their respective inlets and outlets. The layers2102,2104and2106are omitted fromFIG.5bfor clarity.

In this example, instead of a separate member that is submerged within the anode layer the anode in the cell2100is provided by an portion2158of the housing2112that is connected to a power source via the connection and in electrical contact with the lithium-alloy material in the anode layer2102, but that is electrically isolated from an upper portion of the housing2172that supports the cathode conducting member2124and can be at the same potential as the cathode in some examples. The isolated, anode conductor portion2158of the housing can be electrically isolated from the cathode conducting member2124using electrically insulating/isolating assemblies2160that include gaskets in the arrangement ofFIGS.4-5b, but could also include other mounting structures, such as sealing assemblies and isolating flanges (analogous to isolating flange4180described herein), insulators and other such features, or combinations of two or more such features.

Referring also toFIGS.5cand5d, an version of the apparatus2100is shown with a different style of isolating assembly2160, that includes a layered structure including a sealing assembly and a pair isolating flanges. This arrangement can allow the use of a sealing assembly that may be electrically conductive, because it is sandwiched between a pair of electrically insulating isolating flanges. The apparatus2100has multiple isolating assemblies2160between different portions of the housing2112. One isolating assemblies2160is described in detail below, and the other isolating assemblies2160may have an analogous configuration.

in the illustrated example, the isolating assemblies2160for the cell2100includes a seal assembly2161that can seal the connections between the lower portion2158of the housing2112and the upper portion(s)2172of the housing2112that can be at different electric potentials. In this example, the seal assembly2161is a generally self-healing, freeze seal in having a sealing face2163that is in contact with the interior of the cell2100. Other types of seals may be considered in other embodiments of the present teachings.

In this example, the seal assembly2161includes a body2165that is shaped to match the fittings on the lower portion2158of the housing2112, and has a central aperture2167that is sized receive other portions of the cell2100. Preferably, the body2165is maintained at a seal temperature that is less than the freezing temperature of the electrolyte material using a suitable cooling system. In this example, the body2165is formed from a material with a relatively high thermal conductivity and is provided with an internal, fluid cooling conduit (not shown) through which a coolant fluid (such as water) can be circulated. This configuration can help ensure that substantially all of body2165will be at approximately the same seal temperature, including its outward facing surfaces that are likely to be in contact with the molten electrolyte. Suitable materials for the body2165may include copper, aluminum, steel and the like.

When the cell2100is in operation, electrolyte material can flow into contact with the surfaces of the body2165that face and are exposed to the interior of the chamber, such as surface2163. With the body2165maintained at the seal temperature, molten catholyte material in contact with the body2165surfaces can solidify/freeze thereby forming a skin or protective layer of frozen electrolyte material. This protective layer can protect the body2165from exposure to the molten electrolyte and may also provide at least some degree of thermal and/or electrical insulation for the body (as the frozen electrolyte is not as conductive as the molten electrolyte). The protective layer may build up to a generally steady state thickness as the system is in use, where its inner surface is cooled by the body2165and its outer surface is generally at its melting point. The thickness may vary based on the operating conditions of the cell, but may be between about 0.5 mm and about 25 mm. The build-up of frozen electrolyte on the surface of the body2165can also extend to cover some adjacent structures to help protect them as well. In this example, isolating flanges2180are provided on either side of the body2165. The isolating flanges2180are made from an electrically insulating material and are disposed between body2165and the lower portion2158of the housing sidewall, and between body2165and the upper portion2172of the housing sidewall. The isolating flange2180can be made from any suitable material, including a ceramic material, and can be configured and attached in a way that is analogous to how isolating flange4180is configured and attached. In the illustrated example, each wherein each isolating flange2180has an interior face2169that is exposed to the interior chamber and may be in contact with its contents. These interior faces2169are proximate the body2165and the sealing face2163. Due to this proximity, the layer of frozen electrolyte that forms on the sealing face2163may extend beyond the face2163and cover at least a portion of the adjacent faces2169while the cell2100is in use, such that each interior face2169is at least partially covered with the layer of frozen electrolyte material, which may help protect the isolating flanges2180.

The testing was conducted and demonstrated the application of a seal assembly that is an analogous to sealing assembly2165described herein, and includes a body or sealing freeze flange that can be operated at seal temperature that was lower than the freezing temperature of the flowing electrolyte materials used in the test. The freeze flange sealing assemblies were tested at a seal temperatures between 40 degrees Celsius and 60 degrees Celsius and this testing demonstrated that the assemblies do produce a layer of frozen electrolyte on the surface of the freeze flange as described herein.

This cell2100is configured as a generally elongate, conduit or pipe-like vessel, having a housing2112that extends along a cell axis2170. This type of structure can help provide a relatively large surface area for the anode layer2102and other layers2104and2106, while also being relatively easy to manufacture and to seal in a sufficiently air-tight manner (e.g. to help reduce contamination/reaction of the refined metal layer2106).

This example also illustrates an alternative cathode configuration that may be used with cell2100, and cell100and any other compatible cell arrangements. Referring also toFIG.6, in this example the cathode conducting member2124is configured as a collection or hood type structure that is submerged within the cell2100and electrically connected to the power source using connections2126. The hood defined by the cathode conducting member2124in this example is configured as a generally, curved conduit section with an open-bottom. Providing a curved profile may help facilitate extraction of the refined lithium metal as it may be less likely to get caught in the corners of the hood. This hood has an upper wall portion2162that is curved, and downwardly depending curved sidewall portions2164that define a lower opening2166that is configured to catch the molten, refined metal. An aperture2168is provided at a high point on the upper wall portion2162and is connectable to the inlet end of the refined metal extraction conduit2128. When the cell2100is in use, refined metal collecting within the hood defined by the cathode conducting member2124can pass through the aperture2168in the cathode conducting member2124while being extracted. While a single aperture2168and single refined metal extraction conduit2128are shown in this example, other embodiments of the cathode conducting member2124may have more than one aperture2164and corresponding refined metal extraction conduit2128.

Referring toFIG.13, portions of another schematic example of a cell3100are illustrated, with other portions being omitted for clarity. Cell3100is analogous to cell100and like features are labelled using like reference characters indexed by 3000. In this example, a housing3112is configured as an elongate, pipe-like housing and contains the anode layer3102, electrolyte layer3104and refined metal, product layer3106and a cover gas headspace3107. In this example, the anode conductor member3120is provided by a portion3158of the housing3112and the cathode conducting member3124is provided by an upper portion3172of the housing3112, which is electrically isolated from the a suitable isolating assembly3160, that can be a gasket, ceramic isolating flange or other suitable member. This may help simply construction of the cell3100and/or may help reduce its overall size and complexity, as compared to cells where the cathode is a separate member. The cell3100may be configured as a flow-through cell (having appropriate inlets and outlets) or as a static or batch cell.

Referring toFIGS.7-9, another example of an electrorefining cell4100is illustrated. Cell4100is analogous to cell100and like features are labelled using like reference characters indexed by 4000. In this example, the cell4100includes a housing4112that defines an interior chamber that contains an anode layer4102, a refined metal, product layer4106and a layer of molten salt electrolyte layer4104positioned therebetween. A cover gas headspace4107is contained above the product layer4106. This cell4100is configured as a static cell, and does not have feedstock or electrolyte inlets and outlets as illustrated in this example (but such inlets and outlets could be provided). InFIG.10bathe layers4102,4104and4106are identified using different cross-hatching. The layers4102,4104and4106are omitted fromFIGS.8aand9for clarity.

In this example, a housing4112is configured as a generally vertical, pipe-like housing that includes an upper portion4172of the housing sidewall and a lower portion4158of the housing sidewall that are formed from different pieces and are joined together as described herein. In use the upper portion4172and the lower portion4158co-operate to help define a common interior chamber of the cell4100and are electrically isolated from each other such that they can be at different electric potentials when the cell4100is in use. Electrically isolating the sidewall portions4172and4158allows these sidewall portions to function as the cathode conducting member4124and anode conductor member4120respectively, when the sidewall portions4172and4158are connected to a suitable power source (not shown in these figures). This may help simply construction of the cell4100and/or may help reduce its overall size and complexity.

In this example, the sidewall portions4172and4158(and therefor the anode conductor member4120and cathode conducting member4124) are electrically isolated from each other by an isolating assembly4160. The isolating assembly4160is located between and electrically isolates the lower portion4158of the housing sidewall from the upper portion4158of the housing sidewall. Preferably, the isolating assembly can also and fluidly seal the sidewall portions4158and4172to inhibit leakage of the molten materials within the chamber.

In this example, the isolating assembly4160includes comprises an isolating flange4180made from an electrically insulating material that is disposed between the lower portion4158of the housing sidewall from the upper portion4172of the housing sidewall and is exposed to at least the electrolyte layer4104. The isolating flange4180can be made from any suitable material, including a ceramic material.

The isolating flange4180can be attached to the housing portions4158and4172in any suitable manner that provides the desired mechanical connection, and preferably also provides fluid sealing. In the illustrated example, the lower portion4158of the housing sidewall includes a lower mounting lip4182that extends laterally outwardly from the sidewall and forms a generally annular or ring-like flange at the upper end of the lower portion4158. The mounting lip4182includes a plurality of through-holes that function as a lower fastening apertures4184that are sized and configured to receive suitable, and preferably removable fasteners as described herein. The mounting lip4182may be integrally formed with the axially extending sidewall portion4158, or may be made of a separate piece that his joined to the sidewall portion4158.

Similarly, the upper portion4172of the housing sidewall includes an upper mounting lip4186that extends laterally outwardly from the sidewall and forms a generally annular or ring-like flange at the lower end of the upper portion4172. The mounting lip4186includes a plurality of through-holes that function as a upper fastening apertures4188that are sized and configured to receive suitable, and preferably removable fasteners as described herein. The mounting lip4186may be integrally formed with the axially extending sidewall portion4172, or may be made of a separate piece that his joined to the sidewall portion4172. As shown herein, the upper apertures4188are registered above respective ones of the lower apertures4184.

In this arrangement, the isolating flange4180also includes a plurality of holes that function as a flange fastening apertures4190that aligned with and registered between the with the lower and upper fastening apertures4184and4188so that a bolt or other fastener can extend through the apertures4184,4188and4190.

While any suitable fastener may be used, to help provide the desired electrical isolation between the wall portions4158and4172, preferably the fastener that is used in the isolating assembly4160includes an electrically isolating fastener extending through the lower, flange and upper fastening apertures4184,4190and4188to join the lower portion4158and the upper portion4172of the housing sidewall. In the illustrated example, wherein an isolating fastener4192includes an electrically insulating sleeve4194extending between the lower fastening aperture4184and the upper fastening aperture4188and receiving an electrically conductive bolt4196having a head4198adjacent one of the upper mounting lip or lower mounting lip (the upper lip4186in this example) and an electrically conductive nut4200threaded onto the bolt4196and adjacent the other of the upper mounting lip or lower mounting lip (the lower in this example) and at an opposing second end of the bolt4196. To help isolate the electrically conductive bolt4196and nut4200from the mounting lips4182and4186, the isolating assembly4160can include electrically isolating spacers/washers, such as electrically isolating spacers4202compressed between the head4198and the upper mounting lip4186and electrically isolating spacer4204compressed between the nut4200and the lower mounting lip4182. Optionally, at least one of the insulating sleeve4194, the electrically isolating spacers4202and electrically isolating spacers4204is formed from the same material as the isolating flange4180.

Optionally, the isolating assembly4160can also include additional sealing and isolating gaskets4206can be included between the flange4180and mounting lips4182and4186to help enhance the performance of the isolating assembly4160. These gaskets can be made from any suitable material, including vermiculite, mica and the like.

In this example, when the refined lithium metal is collected in the product layer4106it can be periodically extracted via a refined metal extraction conduit4128, or by removing the top cover of the housing4112.

Referring toFIGS.10-12, another example of an electrorefining cell5100is illustrated. The cell5100is generally analogous to the cell100and like features are indicated using like reference characters indexed by 5000. In this example, the cell5100includes an anode layer5102, having a respective feedstock inlet5108and feedstock outlet5110, a refined metal layer5106and a layer of molten salt electrolyte5104positioned therebetween, with a respective electrolyte inlet5132and electrolyte outlet5134. InFIG.11the layers5102,5104and5106are identified using different cross-hatching that extends only part way across the cell5100so that the underlying structure is also visible in part of the drawing. This partial extension of the layers5102,5104and5106is for illustrative clarity only, and in operation the layers5102,5104and5106would extend the length of the housing5112, between their respective inlets and outlets. The layers5102,5104and5106are omitted fromFIG.12for clarity.

In this example, instead of a separate member that is submerged within the anode layer the anode in the cell5100is provided by an portion5158of the housing5112that is connected to a power source via the connection and in electrical contact with the lithium-alloy material in the anode layer5102, but that is electrically isolated from the cathode conducting member5124. The isolated, anode portion5158of the housing can be electrically isolated from the cathode conducting member5124using electrically insulating/isolating assemblies5160, having an isolating flange5180and including gaskets5206, but could also include other mounting structures, such as insulators. The fasteners used in cell5100can be analogous to the isolating fasteners described in relation to cell4100, and the isolating assembly5160may be generally analogous to the assembly4160.

This cell5100is configured as a generally elongate, conduit-like vessel that is generally rectangular rather than round, having a housing5112that extends along a cell axis5170. This type of structure can help provide a relatively large surface area for the anode layer5102and other layers5104and5106, while also being relatively easy to manufacture and to seal in a sufficiently air-tight manner (e.g. to help reduce contamination/reaction of the refined metal layer5106).

In this example, the cell5100includes cathode conducting member s5124that can be connected to a suitable power source using connectors5126, but that are also in electrical contact with the upper portion5172of the housing5112, such that the upper portion5172and cathode conducting member s5124are all at the cathode potential when the cell5100is in use. An aperture5168is provided at a high point on housing5112and is connectable to the inlet end of the refined metal extraction conduit5128. When the cell5100is in use, refined metal collecting within the product layer5106can pass through the aperture5168while being extracted. While a single aperture5168and single refined metal extraction conduit5128are shown in this example, other embodiments may have more than one aperture and corresponding refined metal extraction conduit.

Optionally, to help smooth the flow of the electrolyte material entering the interior chamber of the cell5100, the cell5100may include an electrolyte settling chamber that is disposed within the housing5112between the electrolyte inlet5132and the electrolyte layer5104. In this example, a region of the cell5100that is proximate and below the electrolyte inlet5132can function as an electrolyte settling chamber5210. This electrolyte settling chamber5210is bounded by a portion of the housing sidewall and an internal weir5212that separates the electrolyte settling chamber5210from the anode layer5102. Electrolyte material flowing in via inlet5132can first enter the electrolyte settling chamber5210where it can mix with electrolyte material that is already in the electrolyte settling chamber5210, and material that reaches the top of the weir5212can then flow into the electrolyte layer5104. In this example, the electrolyte settling chamber5210receives and temporarily contains the incoming electrolyte material, so that the electrolyte material exiting the electrolyte settling chamber5210by flowing over the weir5212is less turbulent than the electrolyte material entering the electrolyte settling chamber5210from the inlet5132.

While this invention has been described with reference to illustrative embodiments and examples, the description is not intended to be construed in a limiting sense. Thus, various modifications of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to this description. It is therefore contemplated that the appended claims will cover any such modifications or embodiments.

All publications, patents and patent applications referred to herein are incorporated by reference in their entirety to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference in its entirety.