Subambient temperature transfer system for cold forming processes

Abstract

A system configured to roll metal into a foil. The system includes spaced apart working rolls to receive metal therebetween. The working roll is configured to press against the metal to roll the metal into a foil. A cooling subsystem is spaced apart from the working rolls on a working line configured to supply metal to the working rolls. The cooling subsystem is configured to cool the metal as it moves along the working line.

Description

Technical Field

[0001] The information provided in this section is for the purpose of generally presenting the background of the present disclosure. To the extent described in this section, the work of the presently named inventors and aspects of the description that may not otherwise be prior art at the time of filing are neither explicitly nor implicitly admitted to be prior art with respect to the present disclosure.

[0002] The present disclosure relates to a sub-ambient temperature conveying system for a cold forming process configured to roll a metal having a relatively low melting temperature into foil. Background Art

[0003] Various manufacturing processes involve rolling metals into foils. For example, lithium can be rolled into thin foil to form the active layer of a battery anode. The lithium foil can be applied to any suitable current collector, such as copper foil, to form the anode. Indium, tin, lead, and sodium are additional examples of metals that can be rolled into foil. In some cases, the metals may have relatively low melting temperatures. Summary of the Invention

[0004] In various features, the present disclosure includes a system configured to roll metal into foil. The system includes spaced work rolls to receive metal therebetween. The work rolls are configured to press against the metal to roll the metal into foil. A cooling subsystem is spaced from the work rolls on a work line configured to feed metal to the work rolls. The cooling subsystem is configured to cool the metal as it moves along the work line.

[0005] In further features, the metal includes at least one of lithium, indium, tin, lead, and sodium.

[0006] In further features, the foil is configured as an active layer of a battery electrode.

[0007] In further features, the cooling subsystem includes a chill roller defining a channel therein, the channel configured to receive a coolant to cool the chill roller and to cool a foil in contact with the chill roller.

[0008] In further features, the channel extends completely through the chill roller parallel to the axis of rotation of the chill roller.

[0009] In further features, the channel extends non-linearly relative to the axis of rotation of the roller.

[0010] In further features, the channel includes an inlet and an outlet located at the same side of the cooling roller.

[0011] In further features, the present disclosure includes a polymeric support member positioned between adjacent ones of the chill rolls.

[0012] In a further feature, the cooling subsystem includes a housing adjacent to the chill rollers, the housing defining a reservoir configured such that outer surfaces of the chill rollers are accessible from within the housing and coolant present within the reservoir contacts the outer surfaces of the rollers. A gap is defined between the housing and each chill roller to provide rotational clearance for the chill rollers and to provide controlled release of coolant from the reservoir onto the chill rollers to cool and lubricate the chill rollers.

[0013] In further features, adjacent ones of the cooling rollers are offset from one another.

[0014] In a further feature, the cooling subsystem includes an upper guide and a lower guide opposite the upper guide, the upper guide and the lower guide being spaced apart to accommodate metal therebetween; the upper guide defining perforations configured to direct chilled air through the upper guide to the metal to cool the metal using an air blanket; and the lower guide being made of a thermally conductive material and defining cooling channels configured to circulate a coolant through the lower guide to cool the metal, the air blanket urging the metal against the lower guide.

[0015] In a further feature, the cooling subsystem includes an upper guide and a lower guide opposite the upper guide, the upper guide and the lower guide being spaced apart to accommodate metal therebetween; the upper guide including guide rollers made of a thermally insulating material, the guide rollers configured to press the metal against the lower guide; and the lower guide is made of a thermally conductive material and defines a cooling channel configured to circulate a coolant through the lower guide to cool the metal, the guide rollers configured to push the metal against the lower guide.

[0016] In a further feature, the cooling subsystem includes an upper guide and a lower guide opposite the upper guide, the upper guide and the lower guide being spaced apart to accommodate metal therebetween; the upper guide defining perforations configured to direct cooled air through the upper guide to the metal to cool the metal using an air blanket; and the lower guide including a heat pump configured to cool the metal, the air blanket urging the metal against the lower guide.

[0017] In further features, the cooling subsystem includes an upper guide and a lower guide opposite the upper guide, the upper guide and the lower guide being spaced apart to accommodate metal therebetween; the upper guide including guide rollers made of a thermally insulating material, the guide rollers configured to press the metal against the lower guide; and the lower guide including a Peltier stage configured to cool the metal, the guide rollers configured to push the metal against the lower guide.

[0018] In further features, the cooling subsystem includes a load guide defining a main channel therethrough, the work line extending through the main channel, a plurality of upper channels located above the main channel, and a plurality of lower channels located below the main channel; and the upper channels and the lower channels are configured to direct coolant to the metal.

[0019] Among other features, the present disclosure also includes a system configured to roll metal into foil. The system includes work rolls spaced apart to receive metal therebetween, the work rolls configured to press against the metal to roll the metal into foil, and a cooling subsystem spaced apart from the work rolls on a work line configured to feed metal to the work rolls, the cooling subsystem including upper and lower guides located on opposite sides of the work line, at least one of the upper and lower guides configured to be cooled with a coolant to cool the metal as it moves through the cooling subsystem.

[0020] In further features, at least one of the upper guide and the lower guide includes a cooling roller defining a cooling channel configured to circulate a coolant through the cooling roller.

[0021] In further features, one of the upper guide and the lower guide is configured to push metal against the other of the upper guide and the lower guide.

[0022] The present disclosure also provides a system configured to roll metal into foil. The system includes work rolls spaced apart to receive metal therebetween, the work rolls configured to press against the metal to roll the metal into foil; and a cooling subsystem spaced apart from the work rolls on a work line configured to feed metal to the work rolls. The cooling subsystem includes upper and lower guides located on opposite sides of the work line, at least one of the upper and lower guides configured to cool the metal as it moves through the cooling subsystem. The metal includes at least one of lithium, indium, tin, lead, and sodium, and the foil is configured as an active layer of a battery electrode.

[0023] In further features, at least one of the upper guide and the lower guide includes a heat pump configured to cool metal. Solution 1. A system configured to roll metal into foil, the system comprising: work rolls spaced apart to receive metal therebetween, the work rolls being configured to press against the metal to roll the metal into foil; and A cooling subsystem is spaced apart from the work rolls on a work line configured to supply metal to the work rolls. The cooling subsystem is configured to cool the metal as it moves along the work line. Option 2. The system of Option 1, wherein the metal comprises at least one of lithium, indium, tin, lead, and sodium. Option 3. The system of Option 1, wherein the foil is configured as an active layer of a battery electrode. Option 4. The system of Option 1, wherein the cooling subsystem includes a cooling roller defining a channel therein, the channel configured to receive a coolant to cool the cooling roller and to cool a foil in contact with the cooling roller. Option 5. A system according to Option 4, wherein the channel extends completely through the cooling roller parallel to the rotation axis of the cooling roller. Option 6. A system according to Option 4, wherein the channel extends non-linearly relative to the axis of rotation of the roller. Option 7. The system of Option 4, wherein the channel comprises an inlet and an outlet located on the same side of the cooling roller. Option 8. The system according to Option 4 further includes a polymer support member located between adjacent ones of the cooling rollers. Option 9. The system of Option 4, wherein the cooling subsystem includes a housing adjacent to the chill roller, the housing defining a reservoir, the reservoir being configured such that an outer surface of the chill roller is accessible from within the housing and coolant present within the reservoir contacts the outer surface of the roller, and A gap is defined between the housing and each chill roller to provide rotational clearance for the chill rollers and to provide controlled release of coolant from the container onto the chill rollers to cool and lubricate the chill rollers. Option 10. The system of Option 4, wherein adjacent ones of the cooling rollers are offset from one another. Option 11. The system of Option 1, wherein: The cooling subsystem includes an upper guide and a lower guide opposite the upper guide, the upper guide and the lower guide being spaced apart to receive metal therebetween; The upper guide defines perforations configured to direct cooled air through the upper guide to the metal to cool the metal using an air blanket; and The lower guide is made of a thermally conductive material and defines cooling channels configured to circulate a coolant through the lower guide to cool the metal, the air blanket urging the metal against the lower guide. Option 12. The system of Option 1, wherein: The cooling subsystem includes an upper guide and a lower guide opposite the upper guide, the upper guide and the lower guide being spaced apart to receive metal therebetween; the upper guide includes guide rollers made of a thermally insulating material, the guide rollers being configured to press the metal against the lower guide; and The lower guide is made of a thermally conductive material and defines cooling channels configured to circulate a coolant through the lower guide to cool the metal, and the guide rollers are configured to push the metal against the lower guide. Option 13. The system of Option 1, wherein: The cooling subsystem includes an upper guide and a lower guide opposite the upper guide, the upper guide and the lower guide being spaced apart to receive metal therebetween; The upper guide defines perforations configured to direct cooled air through the upper guide to the metal to cool the metal using an air blanket; and The lower guide includes a heat pump configured to cool the metal, and the air blanket pushes the metal against the lower guide. Option 14. The system of Option 1, wherein: The cooling subsystem includes an upper guide and a lower guide opposite the upper guide, the upper guide and the lower guide being spaced apart to receive metal therebetween; the upper guide includes guide rollers made of a thermally insulating material, the guide rollers being configured to press the metal against the lower guide; and The lower guide includes a Peltier stage configured to cool the metal, and the guide rollers are configured to push the metal against the lower guide. Option 15. The system of Option 1, wherein: The cooling subsystem includes a load guide defining a main passage therethrough, the working line extending through the main passage, a plurality of upper passages located above the main passage, and a plurality of lower passages located below the main passage; and The upper and lower channels are configured to direct coolant to the metal. 16. A system configured to roll metal into foil, the system comprising: work rolls spaced apart to receive metal therebetween, the work rolls being configured to press against the metal to roll the metal into foil; and a cooling subsystem spaced from the work rolls on a work line configured to feed metal to the work rolls, the cooling subsystem comprising upper and lower guides located on opposite sides of the work line, at least one of the upper and lower guides configured to be cooled with a coolant to cool the metal as it moves through the cooling subsystem. Option 17. The system of Option 16, wherein at least one of the upper guide and the lower guide comprises a cooling roller defining a cooling channel configured to circulate a coolant through the cooling roller. Option 18. The system of Option 16, wherein one of the upper guide and the lower guide is configured to push the metal against the other of the upper guide and the lower guide. 19. A system configured to roll metal into foil, the system comprising: work rolls spaced apart to receive metal therebetween, the work rolls being configured to press against the metal to roll the metal into foil; and a cooling subsystem spaced from the work rolls on a work line configured to feed metal to the work rolls, the cooling subsystem comprising upper and lower guides located on opposite sides of the work line, at least one of the upper and lower guides configured to cool the metal as it moves through the cooling subsystem; The metal comprises at least one of lithium, indium, tin, lead and sodium, and the foil is configured as an active layer of a battery electrode. Option 20. The system of Option 19, wherein at least one of the upper guide and the lower guide comprises a heat pump configured to cool metal.

[0024] Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims and the accompanying drawings.The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present disclosure will be more fully understood from the detailed description and accompanying drawings, in which:

[0026] Figure 1 is a cross-sectional view of an exemplary battery cell including a current collector coated with an active layer;

[0027] Figure 2 An exemplary rolling system for rolling metal into metal foil according to the present disclosure is shown;

[0028] Figure 3A is a perspective view of an exemplary cooling subsystem for cooling metal according to the present disclosure;

[0029] Figure 3B yes Figure 3A A perspective view of an exemplary cooling roller of a cooling subsystem of FIG.

[0030] Figure 3C Additional exemplary chill rolls according to the present disclosure are shown;

[0031] Figure 3D An alternative chill roll according to the present disclosure is shown;

[0032] Figure 3E shows an additional chill roll according to the present disclosure;

[0033] Figure 3F An additional cooling roller according to the present disclosure is shown;

[0034] Figure 4A is a perspective view of an additional cooling subsystem according to the present disclosure;

[0035] Figure 4B yes Figure 4A A perspective view of an upper shell and a lower shell of a cooling subsystem of FIG. 1 , wherein the shell cooperates with a cooling roller;

[0036] Figure 4C yes Figure 4B A cross-sectional view of an upper shell and a cooling roller, wherein the upper shell is filled with coolant;

[0037] Figure 4D Shown is the clearance gap between the upper housing and one of the cooling rollers;

[0038] Figure 5A is a perspective view of another cooling subsystem according to the present disclosure;

[0039] Figure 5B yes Figure 5A a side view of an upper cooling guide and a lower cooling guide of a guide system;

[0040] Figure 6 is a perspective view of another cooling subsystem according to the present disclosure;

[0041] Figure 7 is a perspective view of an additional cooling subsystem according to the present disclosure;

[0042] Figure 8 is a perspective view of another cooling subsystem according to the present disclosure;

[0043] Figure 9 Another cooling subsystem according to the present disclosure is shown;

[0044] Figure 10 shows an additional cooling subsystem according to the present disclosure; and

[0045] Figure 11 is a side view of another exemplary rolling system including a cooling subsystem with offset cooling rolls according to the present disclosure.

[0046] Among the drawings, reference numerals may be repeated to identify similar and / or identical elements. DETAILED DESCRIPTION

[0047] The present disclosure includes a system configured to roll a metal into foil. The metal can be any suitable metal with a relatively low melting temperature, such as one or more of lithium, indium, tin, lead, sodium, and the like. The foil can be configured for any suitable automotive or non-automotive application. For example, the foil can be used as the active layer of a battery electrode. The battery can be configured for use with a vehicle and can also be configured for non-vehicle use.

[0048] Lithium, indium, tin, lead, sodium, and other metals with relatively low melting temperatures lack mechanical strength at room temperature, which presents challenges in rolling such metals into foil. For example, such metals are susceptible to tearing and breaking during rolling and may stick to the work rolls. The present disclosure includes a cooling subsystem configured to reduce the temperature of the metal before it reaches the work rolls and / or between the work roll sets. The system of the present disclosure provides for rolling metal at below-ambient temperatures in a dry chamber environment having a dew point below the rolling temperature of the metal. Lowering the temperature of the metal with a relatively low melting temperature provides the metal with increased strength and hardness, which allows the metal to be rolled into thinner foil gauges. The present disclosure cools the metal before it reaches the work rolls in various ways, as described in detail herein.

[0049] Figure 1 An exemplary battery cell 10 is shown. The battery cell 10 can be configured for any suitable application, such as any suitable automotive or non-automotive application. The battery cell 10 includes C cathode electrodes 20, A anode electrodes 40, and S separators 32 arranged in a predetermined order into a battery stack 12, which is housed in a housing 48. C, A, and S are integers, each greater than 1. In some examples, A=C+1. The C cathode electrodes 20-1, 20-2, ..., and 20-C include a cathode active layer 24 disposed on one or both sides of a cathode current collector 26. The A anode electrodes 40-1, 40-2, ..., and 40-A include an anode active layer 42 disposed on one or both sides of an anode current collector 46.

[0050] refer to Figure 2 , the anode active layer 42 may include metal 112 that is rolled into foil by the rolling system 110 of the present disclosure. The rolling system 110 includes a plurality of work rolls 120 arranged along a work line. The work rolls 120 are generally arranged in pairs spaced apart along the work line. Each pair of work rolls 120 is spaced apart to receive the metal 112 therebetween and is configured to press against the metal 112 as the metal 112 is fed along the work line between the rolls 120 or each pair of rolls to roll the metal 112 into foil. The work rolls 120 may be made of any suitable material, including but not limited to steel, aluminum, copper, etc. The work rolls 120 may be formed in any suitable manner. For example, the work rolls 120 may be forged, cast, formed by additive manufacturing, etc. Additive manufacturing may be metal additive manufacturing followed by machining.

[0051] Figure 3A An exemplary cooling subsystem 210 configured to cool metal 112 according to the present disclosure is shown. The cooling subsystem 210 can be arranged at any suitable location along the working line of the rolling system 110 such that the cooling subsystem is in line with the work rolls 120. For example, the cooling subsystem 210 can be arranged upstream of all the work rolls 120 and / or between one or more pairs of work rolls 120. Multiple cooling subsystems 210 can be included such that the cooling subsystem 210 can be arranged between multiple different pairs of work rolls 120. For example and as Figure 2 As shown in FIG, the cooling subsystem 210 can be arranged in Figure 2 The same may be true for any other cooling subsystem 310 , 410 , 510 , 610 , 710 described herein at one or more of the downward-pointing arrows.

[0052] The cooling subsystem 210 includes a plurality of cooling rollers 220 disposed both above and below the metal 112. The cooling rollers 220 are spaced far enough apart so as not to reduce the thickness of the metal 112 as the metal 112 passes between the upper and lower sets of cooling rollers 220. The cooling rollers 220 are configured to guide the metal 112 along the work line and to deliver the metal 112 to the work rollers 120. Figure 3B , support members 222 are positioned between adjacent ones of the cooling rollers 220. The support members 222 may be made of any material suitable for supporting the metal 112 as it moves past the cooling rollers 220, such as any suitable polymeric material. The support members 222 may be configured to generally provide a guide and platform for the metal 112 to pass over.

[0053] The chill roll 220 is cooled by any suitable coolant circulated through cooling channels defined within the chill roll 220. Cooling the chill roll 220 cools the metal 112 in contact with the chill roll 220, which strengthens the metal 112 and allows the metal 112 to be rolled into a relatively stronger and thinner foil gauge. Examples of coolants that can be used to cool the chill roll 220 include, but are not limited to, the following: silicone oil; liquid N2; liquid Ar; and liquid CO2.

[0054] The coolant may be cooled in any suitable manner, such as with any suitable cooler 650 (e.g., Figure 9 and 10). Cooler 650 can be any suitable cooler or other cooling device configured to cool the coolant to any suitable temperature (e.g., at least below ambient or room temperature). The temperature can depend on the specific metal 112 being rolled by the rolling system 110. For example, the temperature can be at or below the temperature at which the metal experiences tearing or breaking during rolling by the rollers 120. More specifically, cooler 212 can be configured to circulate the coolant in a range of 25°C to -70°C. Liquid Ar or liquid N2 are examples of coolants that can be used to achieve temperatures below -70°C. The metal being rolled can be at any suitable temperature. For example, the temperature of the metal being rolled can be from -80°C to 25°C, such as -40°C or about -40°C.

[0055] The cooling roller 220 can be configured in a variety of different ways to fluidly cooperate with the cooler 650 and be cooled by the coolant. Figure 3C , the cooling subsystem 210 may include a cooling roller 220A defining channels 230. The channels 230 are configured to receive cooled coolant from the chiller 650. The channels 230 are formed in any suitable manner, such as by drilling into a forged or cast solid cooling roller 220A. The channels 230 extend completely through the cooling roller 220A along or parallel to the axis of rotation of the roller 220A. Each of the channels 230 includes an inlet 232 and an outlet 234 located on opposite ends of the cooling roller 220A.

[0056] Figure 3D An additional exemplary cooling roller 220B for use with the cooling subsystem 210 according to the present disclosure is shown. The cooling roller 220B defines a channel 240 that, in the example shown, extends completely through the cooling roller 220B from an inlet 242 to an outlet 244 located on an opposite side of the cooling roller 220B. During additive manufacturing of the roller 220B, the channel 240 is defined within the roller 220B. The channel 240 extends nonlinearly across the cooling roller 220B in a generally zigzag pattern. The channel 240 is configured to receive cooled coolant from the chiller 650.

[0057] refer to Figure 3E Alternatively, cooling subsystem 210 may include a cooling roller 220C. Cooling roller 220C is cast around tube 250, which may be made of copper or any other suitable material. Tube 250 defines a passage for coolant. Tubes 250 each include an inlet 252 and an outlet 254 located on the same side of roller 220C. Tubes 250 may alternatively extend completely through roller 220C.

[0058] refer to Figure 3F, the cooling subsystem 210 may alternatively include a cooling roller 220D. The cooling roller 220D defines channels 260, which are generally porous regions of the roller 220D, each channel having an inlet 262 and an outlet 264 located on opposite sides of the channel 260. During additive manufacturing of the roller 220D, the channels 260 are defined within the roller 220D. The channels 260 are configured to receive a coolant.

[0059] Figures 4A-4D An additional cooling subsystem 310 for cooling the metal 112 according to the present disclosure is shown. The cooling subsystem 310 is configured to direct coolant onto the outer surface of the roller 220. The cooling subsystem 310 includes a housing 320 on opposite sides of the metal 112. The housing 320 includes an upper housing and a lower housing. The housing 320 defines a container 322 that is configured to receive a coolant, such as coolant cooled by the chiller 650. The housing 320 is configured to support the cooling roller 220 in any suitable manner that will allow the cooling roller 220 to rotate and be exposed to the coolant 324 within the container 322 to cool the cooling roller 220 and the metal 112 in contact with the cooling roller, such as, for example, Figure 4C As shown in . Figure 4D A gap 326 is defined between the housing 320 and the cooling roller 220 to allow the cooling roller 220 to rotate and allow the coolant 324 to flow from the container 322 and onto the cooling roller 220. The gap 326 can be of any suitable size. For example, the gap 326 can provide a rotational clearance of 0.1 mm to 0.5 mm.

[0060] The coolant 324 can be any suitable liquid coolant, such as silicone oil or liquid argon. The coolant 324 contacts the outer surface of the cooling roller 220 to cool the cooling roller 220. A gap 326 between the housing 320 and the cooling roller 220 allows the coolant 324 to seep down onto the cooling roller 220 to lubricate the cooling roller 220. When the coolant 324 is liquid argon, liquid argon fumes leak from the gap 326 onto the cooling roller 220, providing an inert coating to prevent moisture contamination on the cooling roller 220. Silicone oil and other inert cooling fluids also prevent side reactions with lithium and any potential contamination.

[0061] Figure 5A and Figure 5BAn additional cooling subsystem 410 according to the present disclosure is shown. The cooling subsystem 410 includes an upper guide member 420 and a lower guide member 430 opposite the upper guide member 420. The upper guide member 420 and the lower guide member 430 are spaced apart to accommodate the metal 112 therebetween. The upper guide member 420 defines a perforation 422 configured to direct cooled air from any suitable source of cooled air to the metal 112. For example, the cooler 650 can be configured to cool the air. The upper guide member 420 can be made of any suitable material, including any suitable metal material, such as stainless steel. The upper guide member 420 can be spaced apart from the metal 112 so as not to contact the metal 112. The cooled air directed through the perforation 422 creates an air blanket 424 that pushes the metal 112 against the lower guide member 430.

[0062] The lower guide 430 is generally a hollow shell made of any suitable thermally conductive material, such as copper or any other suitable thermally conductive alloy. The lower guide 430 serves as a load guide for the metal 112 and may include any suitable coating to minimize friction between the metal 112 and the lower guide 430, such as Teflon. Any suitable coolant is circulated through the lower guide 430 to cool the lower guide 430 and the metal 112 pressed against it. For example, the coolant may be silicone oil. As the metal 112 moves between the upper guide 420 and the lower guide 430, the metal 112 is cooled by both the air blanket 424 and the lower guide 430. The lower guide 430 may include an inlet 432 and an outlet 434 to circulate coolant through the lower guide 430 from any suitable source, such as a cooler 650. To facilitate movement of the metal 112 through the lower guide 430, the lower guide 430 can include rounded edges on the downstream end of the lower guide 430 and the upstream end of the lower guide 430. The lower guide 430 can also include any suitable coating, such as Teflon, to minimize friction between the metal 112 and the lower guide 430.

[0063] refer to Figure 6 , the upper guide member 430 can be configured as a guide roller 440. The guide roller 440 is configured to press the metal 112 against the lower guide member 430 to facilitate cooling of the metal 112 through the lower guide member 430. The guide roller 440 can be made of any suitable thermally insulating material. Although only one guide roller 440 is shown, the cooling subsystem 410 can include any suitable number of guide rollers 440.

[0064] Figure 7An additional cooling subsystem 510 is shown for inclusion in the rolling system 110 to cool the metal 112 in accordance with the present disclosure. The cooling subsystem 510 includes an upper cooling guide 520 and a lower cooling guide 530. The upper cooling guide 520 is the same as or substantially similar to the upper cooling guide 420. The upper cooling guide 520 defines perforations 522 configured to direct cooled air toward the metal 112 to cool the metal 112 and create an air blanket that presses the metal 112 into contact with the lower cooling guide 530.

[0065] The lower cooling guide 530 is configured as a Peltier stage, configured to be cooled to a temperature below ambient and configured as a load guide to support the metal 112. The lower cooling guide 530 is generally a solid-state heat pump operating based on the Peltier effect. The lower cooling guide 530 includes an array 540 of p-type and n-type semiconductor elements doped with an electrical carrier. The semiconductor elements are arranged in array 540, electrically connected in series and thermally connected in parallel. This array 540 is then attached to an upper ceramic substrate 550 and a lower ceramic substrate 552, located on opposite sides of the array 540 of semiconductor elements. Generally speaking, heat is absorbed by the upper ceramic substrate 550 and transferred to the lower ceramic substrate 552, which acts as a heat sink. Copper conductors are located between the upper ceramic substrate 550 and the array 540. Copper conductors are also included between the lower ceramic substrate 552 and the array 540.

[0066] The p-type semiconductor of array 540 is doped with certain atoms (having fewer electrons than are needed to complete atomic bonds within the crystal lattice). When voltage is applied, there is a tendency for conduction electrons to complete atomic bonds. When conduction electrons do this, they leave behind "holes," essentially atoms within the crystal lattice that now carry a localized positive charge. Electrons then continually fall into and out of holes, moving to the next available hole. In effect, holes act as electrical carriers. Electrons move relatively freely in copper conductors compared to semiconductors. When electrons leave the p-type and enter the copper on the cold side at upper ceramic substrate 550, holes are created in the p-type as the electrons jump to a higher energy level to match the energy level of electrons already moving in the copper. The additional energy to create these holes comes from absorbing heat. Simultaneously, the newly created holes travel down to the copper on the hot side at lower ceramic substrate 552. Electrons from the hot-side copper move into the p-type and fall into the holes, releasing excess energy as heat.

[0067] The n-type semiconductor of array 540 is doped with atoms that provide more electrons than are needed to complete the atomic bonds within the crystal lattice. When voltage is applied, the extra electrons readily move into the conduction band. However, additional energy is required to match the energy level of the n-type electrons to the energy level of the incoming electrons from the cold-side copper. This extra energy comes from absorbing heat. Finally, when the electrons leave the hot side of the n-type semiconductor, they are free to move again within the copper, dropping to a lower energy level and releasing heat in the process. Thus, using lower cooling guide 530, heat is absorbed on the cold side of the n-type and p-type elements (upper ceramic substrate 550) and released on the hot side of the thermoelectric elements (lower ceramic substrate 552) to cool metal 112.

[0068] refer to Figure 8 , the upper cooling guide 520 can be configured as a guide roller 560. The guide roller 560 is configured to press the metal 112 against the lower cooling guide 530 to facilitate cooling of the metal 112 by the lower cooling guide 530. The guide roller 560 can be made of any suitable thermally insulating material. Although only one guide roller 560 is shown, the cooling subsystem 510 can include any suitable number of guide rollers 560.

[0069] Figure 9 An additional cooling subsystem 610 for inclusion in a rolling system 110 to cool metal 112 according to the present disclosure is shown. The cooling subsystem 610 includes a load guide 620 defining a main channel 630 for the metal 112 and a plurality of coolant channels 640 located on opposite sides of the main channel 630. The coolant channels 640 fluidly cooperate with a cooler 650 to receive cooled coolant from the cooler 650. The coolant channels 640 are configured to direct coolant into the main channel 630 to deposit the coolant on opposite sides of the metal 112. The coolant can be any suitable coolant, such as silicone oil. The silicone oil cools the metal 112 and creates a lubricating film that helps the metal 112 move through the load guide 620. The coolant thus also acts as a lubricant, allowing the metal 112 to move through the main channel 630 without adhering to the load guide 620, thereby enabling a continuous process. The load guide 620 can be made of any suitable material, such as any suitable polymeric material. The load guide 620 can be formed in any suitable manner, such as by any suitable 3D printing process. The metal 112 can be drawn through the load guide 620 in any suitable manner, such as in a vacuum. Thus, the cooling subsystem 610 can be sealed within any suitable airtight chamber 660. The vacuum also draws away any residual moisture to keep the metal 112 inert.

[0070] Figure 10A cooling subsystem 710 is shown according to the present disclosure and is configured to cool the metal 112 using a coolant in the form of a cooled inert gas. The gas can be cooled in any suitable manner, such as by a cooler 650. The cooling subsystem 710 includes a load guide 720 defining a plurality of machined channels 730 configured to direct the cooled inert gas toward the metal 112 to cool the metal 112. The gas is applied under pressure to suspend the metal 112 within the load guide 720.

[0071] Figure 11 An exemplary chill roll arrangement is shown for any suitable chill roll 220 (e.g., chill rolls 220A, 220B, 220C, etc.). The metal 112 can be guided to the chill rolls 220 by guide rolls 224. The chill rolls 220 are staggered or offset relative to one another, which results in a greater surface area of ​​the metal 112 contacting and being cooled by the chill rolls 220. Thus, staggering the chill rolls 220 generally increases the cooling efficiency of the chill rolls 220. The chill rolls 220 can be staggered vertically as shown, or horizontally. The chill rolls 220 are staggered relative to their axis of rotation.

[0072] In the accompanying drawings, the system of the present disclosure is generally shown as a horizontal system oriented to move from left to right. However, the system can be oriented in any suitable alternative orientation. For example, the orientation of the entire rolling mill apparatus (including the cooling rollers) can be changed from horizontal to vertical to take advantage of gravity and minimize the tensile forces (tension) induced on the thin lithium foil during rolling. This can reduce the likelihood of foil tearing during manufacturing.

[0073] The foregoing description is merely illustrative in nature and is in no way intended to limit the present disclosure, its application or use. The broad teachings of the present disclosure can be implemented in various forms. Therefore, although the present disclosure includes specific examples, the true scope of the present disclosure should not be so limited, because after studying the drawings, description and appended claims, other modifications will become apparent. It should be understood that, without changing the principles of the present disclosure, one or more steps within the method can be performed in a different order (or simultaneously). In addition, although each of the embodiments is described above as having certain features, any one or more of those features described with reference to any embodiment of the present disclosure can be implemented in the features of any of the other embodiments and / or combined with the features of any of the other embodiments, even if the combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and the permutation of one or more embodiments with each other is still within the scope of the present disclosure.

[0074] Various terms are used to describe the spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.), including "connected," "engaged," "coupled," "adjacent," "next to," "on top of," "above," "below," and "disposed." Unless explicitly described as "direct," when describing a relationship between a first and a second element in the above disclosure, the relationship can be a direct relationship in which there are no other intervening elements between the first and second elements, but can also be an indirect relationship in which there are one or more intervening elements (spatially or functionally) between the first and second elements. As used herein, the phrase "at least one of A, B, and C" should be interpreted to mean a logical (A or B or C) using a non-exclusive logical "OR" and should not be interpreted to mean "at least one of A, at least one of B, and at least one of C."

[0075] In a diagram, the direction of an arrow, as represented by an arrow, generally indicates the flow of information (e.g., data or instructions) of interest to the diagram. For example, when component A and component B exchange various information, but the information transmitted from component A to component B is relevant to the diagram, an arrow may point from component A to component B. This unidirectional arrow does not imply that no other information is transmitted from component B to component A. In addition, for information transmitted from component A to component B, component B may send a request for the information or an acknowledgment of receipt of the information to component A.

Claims

1. A system configured to roll metal into foil, the system comprising: work rolls spaced apart to receive metal therebetween, the work rolls being configured to press against the metal to roll the metal into foil; as well as A cooling subsystem is spaced apart from the work rolls on a work line configured to supply metal to the work rolls. The cooling subsystem is configured to cool the metal as it moves along the work line.

2. The system according to claim 1, wherein: The metal includes at least one of lithium, indium, tin, lead, and sodium.

3. The system according to claim 1, wherein: The foil is configured as the active layer of a battery electrode.

4. The system according to claim 1, wherein: The cooling subsystem includes a chill roller defining a channel therein, the channel configured to receive a coolant to cool the chill roller and to cool a foil in contact with the chill roller.

5. The system according to claim 4, wherein: The channel extends completely through the cooling roller parallel to the axis of rotation of the cooling roller.

6. The system according to claim 4, wherein: The channel extends non-linearly relative to the axis of rotation of the roller.

7. The system according to claim 4, wherein: The channel includes an inlet and an outlet located at the same side of the cooling roller.

8. The system of claim 4, further comprising a polymer support member positioned between adjacent ones of the chill rollers.

9. The system according to claim 4, wherein: a cooling subsystem comprising a housing adjacent to the chill roller, the housing defining a reservoir configured such that an outer surface of the chill roller is accessible from within the housing and coolant present within the reservoir contacts the outer surface of the roller, and A gap is defined between the housing and each chill roller to provide rotational clearance for the chill rollers and to provide controlled release of coolant from the container onto the chill rollers to cool and lubricate the chill rollers.

10. The system according to claim 4, wherein: Adjacent ones of the cooling rolls are offset from each other.

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