Negative electrode, secondary battery including the same, and method for manufacturing the negative electrode

Abstract

The present invention provides a negative electrode, a secondary battery including the same, and a method for manufacturing the negative electrode. An alkali metal secondary battery, comprising a negative electrode constructed from an alkali metal foil applied to only one side of a porous current collector metal foil. The opening in the porous current collector allows alkali metal accessibility on both sides of the negative electrode structure. Such a negative electrode configuration makes it possible to utilize lower cost and more generally available alkali metal foil thicknesses while still achieving a high battery cell cycle life at a significantly reduced cost. Aspects of the present disclosure also include batteries having a porous current collector with increased volumetric energy density and gravimetric energy density, and methods for manufacturing a negative electrode having a porous current collector.

Description

[0001] Related application information

[0002] This application claims the rights of U.S. Provisional Patent Application No. 62 / 812,454, filed on March 1, 2019, entitled Method of Making Perforated Current Collector Using Carrier Film for Secondary Lithium Battery; U.S. Provisional Patent Application No. 62 / 833,487, filed on April 12, 2019, entitled Method of Making Perforated Current Collector Using Carrier Film for Secondary Lithium Battery; U.S. Provisional Patent Application No. 62 / 812,398, filed on March 1, 2019, entitled Perforated Current Collector Design for Lithium Metal Anode and Secondary Battery Containing the Same; U.S. Provisional Patent Application No. 62 / 833,495, filed on April 12, 2019, entitled Perforated Current Collector Design for Lithium Metal Anode and Secondary Battery Containing theSame; and U.S. Provisional Patent Application No. 62 / 833,495, filed on April 12, 2019, entitled Perforated Current Collector Made Via U.S. Provisional Patent Application No. 62 / 812,482, entitled Photo-Lithography for Secondary Lithium Battery; U.S. Provisional Patent Application No. 62 / 833,499, filed on April 12, 2019, entitled Perforated Current Collector Made Via Photo-Lithography for Secondary Lithium Battery; U.S. Provisional Patent Application No. 62 / 812,441, filed on March 1, 2019, entitled Method of Making Perforated Current Collector Using a Perforated Carrier Film for Back-Side Lithium Extrusion and Planarization for Secondary Lithium Battery;The present invention claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 833,500, filed on April 12, 2019, entitled Method of Making Perforated Current Collector Using a Perforated Carrier Film for Back-Side Lithium Extrusion and Planning for Secondary Lithium Battery; U.S. Provisional Patent Application No. 62 / 812,302, filed on March 1, 2019, entitled Large Format Anodes For Secondary Lithium Batteries; U.S. Provisional Patent Application No. 62 / 833,501, filed on April 12, 2019, entitled Large Format Anodes For Secondary Lithium Batteries; and U.S. Provisional Patent Application No. 62 / 833,507, filed on April 12, 2019, entitled Large Format Anodes For Secondary Lithium Batteries. Each of these applications is incorporated herein by reference in its entirety. ; Technical Field

[0003] The present disclosure relates generally to the field of negative electrodes for secondary batteries. Specifically, the present disclosure relates to an alkali metal negative electrode having a porous current collector, a secondary battery containing the same, and a method of making the same. Background Art

[0004] Secondary (also known as rechargeable) lithium metal batteries offer great prospects for the next generation of energy storage devices due to the significantly higher energy density they provide. Unlike conventional lithium-ion batteries that accommodate a negative electrode (also known as a negative electrode) formed from an intercalation material such as graphite, the lithium metal battery negative electrode is formed from a thin sheet of lithium metal such as lithium metal foil coupled to a current collector. The intercalation negative electrode of a lithium-ion battery only provides a matrix structure for lithium ions and does not contribute to energy storage. The lithium metal battery negative electrode is instead partially formed of lithium metal, which contributes to energy storage, thereby significantly increasing volume energy density and weight energy density. During the charge and discharge cycle of a lithium metal battery, lithium metal is deposited on the negative electrode during charging and stripped from the negative electrode during discharge.

[0005] The negative electrode of a secondary lithium battery typically contains a lithium foil applied to both sides of a copper foil current collector. Tests have shown that the performance of the battery tends to improve when the thickness of the lithium foil is reduced, for example, when the thickness of the lithium foil is reduced, for example, to a thickness of less than or equal to approximately 20 μm of the lithium foil on each side of the current collector, the battery cell cycle life tends to be optimized, and the volumetric energy density and weight energy density tend to increase. However, it is challenging to produce such thin layers of lithium foil using currently available lithium foil manufacturing processes, such as by conventional rolling processes, and it is particularly challenging to produce wider rolls, such as greater than 55 mm width. Using conventional rolling processes, the relatively soft and reactive nature of lithium leads to low yields and therefore high costs for manufacturing extremely thin lithium metal foils, such as less than or equal to approximately 10-20 μm in thickness. The manufacturing challenges also constrain the maximum available width of extremely thin lithium metal foils, which in turn limits the area size of secondary lithium metal battery cells that can be produced, thereby limiting the energy capacity of the battery cell. Summary of the invention

[0006] In one implementation, the present disclosure relates to a method of making a negative electrode, comprising receiving an alkali metal foil; receiving a porous current collector foil having opposite first and second sides and a mesh-like structure, the mesh-like structure defining openings, each of the openings having a volume; and laminating the alkali metal foil and the porous current collector foil together on the first side of the porous current collector, wherein the lamination includes forming an extruded portion of the alkali metal foil extending through the opening from the first side to the second side and substantially filling the volume of the opening.

[0007] In one or more embodiments of the method, the laminating step includes completely filling the volume with the extruded portions.

[0008] In one or more embodiments of the method, the laminating step includes extending the extruded portion until the extruded portion is at least substantially flush with the second side of the porous current collector foil.

[0009] In one or more embodiments of the method, the openings in the porous current collector foil define a percent open area greater than 80%.

[0010] In one or more embodiments of the method, the openings in the porous current collector foil define a percent open area greater than 60%.

[0011] In one or more embodiments of the method, the openings in the porous current collector foil define a percent open area greater than 40%.

[0012] In one or more embodiments of the method, the opening has a maximum width greater than 0.5 mm.

[0013] In one or more embodiments of the method, the openings have a circular or polygonal shape and are in a close-packed arrangement.

[0014] In one or more embodiments of the method, the thickness of the current collector foil is from 4 μm to 20 μm.

[0015] In one or more embodiments of the method, the mesh-like structure of the porous current collector has a minimum mesh width extending between adjacent ones of the openings, wherein the minimum mesh width is less than 1 mm.

[0016] In one or more embodiments of the method, the mesh-like structure of the porous current collector has a minimum mesh width extending between adjacent ones of the openings, wherein the minimum mesh width is less than 0.25 mm.

[0017] In one or more embodiments of the method, the mesh-like structure of the porous current collector has a minimum mesh width extending between adjacent ones of the openings, wherein the minimum mesh width is less than 0.15 mm.

[0018] In one or more embodiments of the method, the openings in the current collector are formed using one or more of a perforation process, a rotary punch process, a rotary mold process, a rotary beer half-perforation process, a photolithography process, a photoetching process, an electroforming process, a laser cutting process, and a metal mesh weaving process.

[0019] In one or more embodiments of the method, the second side of the current collector is coated with an alkali metal coating.

[0020] In one or more embodiments of the method, the step of coating includes one or more of vapor deposition, electrodeposition, slot die coating, dip coating, microgravure printing, flexographic printing, or plating during initial charging of the battery cell housing the negative electrode.

[0021] In one or more embodiments of the method, the base metal foil is laminated to only one side of the current collector metal foil.

[0022] In one or more embodiments of the method, the alkali metal foil has a thickness in a range of 1 μm to 1000 μm.

[0023] In one or more embodiments of the method, the Alkali metal foil has a width greater than 55 mm.

[0024] In one or more embodiments of the method, the laminating step includes laminating multiple rows of alkali metal foil in a closely spaced parallel arrangement across the porous current collector foil to form a wide width negative electrode having a width in a range of 55 mm to 300 mm.

[0025] In one or more embodiments of the method, the Alkali metal foil is a first Alkali metal foil, and the method further comprises laminating a second Alkali metal foil and the porous current collector foil together on a second side of the porous current collector.

[0026] In certain aspects, the present disclosure relates to a method of manufacturing a negative electrode, comprising receiving at least one carrier film, a collector metal foil having opposite first and second sides, and an alkali metal foil; laminating the at least one carrier film to the second side of the collector metal foil to form a carrier film-collector foil laminate; forming a plurality of openings in the carrier film-collector foil laminate to form a porous carrier film-collector foil laminate; laminating an alkali metal foil to the first side of the collector metal foil, wherein laminating the alkali metal foil includes forming an extruded portion of the alkali metal foil extending through the opening.

[0027] In one or more embodiments of the method, the plurality of openings each define a volume, and wherein the step of laminating the base metal foil to the first side of the current collector metal foil includes completely filling the volume with the extruded portion.

[0028] In one or more embodiments of the method, the step of laminating the base metal foil to the first side of the current collector metal foil includes extending the extruded portion until the extruded portion is at least substantially flush with the second side of the current collector metal foil.

[0029] In one or more embodiments of the method, the step of laminating the base metal foil includes extending the extruded portion through the entire thickness of the current collector metal foil and through at least a portion of the thickness of the at least one carrier film.

[0030] In one or more embodiments of the method, the at least one carrier film has a first side contacting the collector metal foil and a second opposite side, wherein the step of laminating the alkali metal foil includes extending the extruded portion until the end of the extruded portion is substantially flush with the second side of the at least one carrier film.

[0031] In one or more embodiments of the method, the Alkali metal foil is a first Alkali metal foil, the method further comprising delaminating the at least one carrier film from the current collector metal foil; and laminating a second Alkali metal foil to a second side of the current collector metal foil.

[0032] In one or more embodiments of the method, delaminating the at least one carrier film from the current collector metal foil leaves an extruded portion protruding from the second side of the current collector.

[0033] In one or more embodiments of the method, the extruded portion is planarized through the second side of the porous current collector.

[0034] In one or more embodiments of the method, a flattening monitoring system is used to determine the degree of flattening of the extruded portion.

[0035] In one or more embodiments of the method, a flattening feedback signal is generated according to the determined flattening degree and sent to a flattening system to control the flattening degree.

[0036] In one or more embodiments of the method, the step of determining the degree of planarization includes execution of a machine vision algorithm configured to process an image of the porous current collector to determine the degree of planarization of the extruded portion.

[0037] In one or more embodiments of the method, pressure is applied to the extruded portion to reduce the height of the extruded portion and distribute the extruded portion on the second side of the porous current collector.

[0038] In one or more embodiments of the method, the at least one carrier film has a thickness selected to result in a target height of the extruded portion, the target height being designed and configured for a target thickness and / or volume of alkali metal on the second side of the current collector.

[0039] In one or more embodiments of the method, the at least one carrier film includes a first carrier film and a second carrier film, wherein the step of forming the plurality of openings includes forming openings extending through the thickness of the current collector metal foil and the first carrier film but not extending through the second carrier film.

[0040] In one or more embodiments of the method, the second carrier film is delaminated prior to the step of laminating the alkali metal foil.

[0041] In one or more embodiments of the method, the delaminating step includes removing waste material using a second carrier film, the waste material being created during the step of forming the plurality of openings.

[0042] In one or more embodiments of the method, an alkali metal coating is applied to the second side of the current collector foil.

[0043] In one or more embodiments of the method, the step of applying the alkali metal coating comprises one or more of vapor deposition, electrodeposition, slot die coating, dip coating, microgravure printing, flexographic printing, or plating during initial charging of the battery cell housing the negative electrode.

[0044] In one or more embodiments of the method, the base metal foil is laminated to only one side of the current collector metal foil.

[0045] In one or more embodiments of the method, the openings in the current collector are formed using one or more of a perforation process and a rotary molding process.

[0046] In one or more embodiments of the method, the alkali metal foil has a thickness in a range of 1 μm to 1000 μm.

[0047] In one or more embodiments of the method, the Alkali metal foil has a width greater than 55 mm.

[0048] In one or more embodiments of the method, the step of laminating the alkali metal foil includes laminating multiple rows of alkali metal foil in a closely spaced parallel arrangement across the porous current collector foil to form a wide width negative electrode having a width in a range of 55 mm to 300 mm.

[0049] In one or more embodiments of the method, an extrusion monitoring system is used to determine the extent of extrusion of the alkali metal.

[0050] In one or more embodiments of the method, an extrusion feedback signal is generated according to the determined degree of extrusion and sent to the laminating roller group to control the degree of extrusion.

[0051] In one or more embodiments of the method, the step of determining the extent of extrusion comprises execution of a machine vision algorithm configured to process an image of the at least one carrier film to determine the extent of extrusion of the extruded portion.

[0052] In one or more embodiments of the method, the thickness of the at least one carrier film is from 13 μm to 300 μm.

[0053] In certain aspects, the present disclosure relates to a method of making a lithium metal anode. The method includes receiving a multilayer substrate including a current collector foil layer and at least one additional layer; applying a hole forming process to the multilayer substrate to form a plurality of holes extending through the current collector foil and at least partially through the at least one additional layer; laminating an alkali metal foil to a first side of the current collector foil; extruding the alkali metal foil through the holes to form a plurality of extruded portions of the alkali metal foil extending at least partially through the at least one layer; and removing the at least one additional layer.

[0054] In one or more embodiments of the method, pressure is applied to the extruded portion to distribute the extruded portion on the second side of the current collector.

[0055] In certain aspects, the present disclosure relates to a method of making an alkali metal negative electrode. The method includes laminating an alkali metal foil to a first side of a porous current collector, the current collector having a plurality of pores extending from the first side of the current collector to a second opposite side; extruding the alkali metal foil through the pores in the current collector to form an extruded portion of the alkali metal, wherein the extruded portion extends to at least the second side and substantially fills the pores.

[0056] In one or more embodiments of the method, the Alkali metal foil is a first Alkali metal foil, and the method further includes laminating a second Alkali metal foil to the second side of the porous current collector.

[0057] In one or more embodiments of the method, the pores in the porous current collector define a percent open area greater than 80%.

[0058] In one or more embodiments of the method, the pores in the porous current collector define a percent open area greater than 60%.

[0059] In one or more embodiments of the method, the pores in the porous current collector define a percent open area greater than 40%.

[0060] In one or more embodiments of the method, the apertures have a maximum width greater than 0.5 mm.

[0061] In one or more embodiments of the method, the holes have a circular or polygonal shape and are in a close-packed arrangement.

[0062] In one or more embodiments of the method, the thickness of the current collector is from 4 μm to 20 μm.

[0063] In certain aspects, the present disclosure relates to a secondary battery including an alkali metal negative electrode, a positive electrode, and a separator; wherein the alkali metal negative electrode is manufactured according to any of the above embodiments.

[0064] In certain aspects, the present disclosure relates to a porous current collector metal foil for use with an alkali metal battery negative electrode. The current collector includes opposite first and second sides and a mesh-like structure that defines a plurality of openings extending between the first and second sides, wherein the percent open area defined by the plurality of openings is greater than 40% and the openings each have a width greater than 0.5 mm.

[0065] In one or more embodiments of the current collector, the web-like structure has a substantially uniform width.

[0066] In one or more embodiments of the current collector, the mesh-like structure is designed and configured to maximize the usability of the first side of the base metal foil laminated to the second side.

[0067] In one or more embodiments of the current collector, the mesh-like structure is designed and configured to maximize the uniformity of consumption of the Alkali metal foil laminated to only one side of the current collector.

[0068] In certain aspects, the present disclosure relates to a negative electrode for an alkali metal secondary battery, comprising a porous current collector foil having opposite first and second sides and a mesh structure defining openings, each of the openings having a volume; and an alkali metal foil laminated to only one side of the porous current collector foil, wherein a portion of the alkali metal foil extends through the opening from the first side to the second side and substantially fills the volume of the opening.

[0069] In one or more embodiments of the negative electrode, the openings in the porous current collector foil define a percent open area greater than 40%.

[0070] In one or more embodiments of the negative electrode, the openings in the porous current collector foil define a percent open area from 80% to 90%.

[0071] In one or more embodiments of the negative electrode, the opening has a width from 0.5 mm to 1.5 mm.

[0072] In one or more embodiments of the negative electrode, the mesh-like structure of the porous current collector has a minimum mesh width extending between adjacent ones of the openings, wherein the minimum mesh width is less than 1 mm.

[0073] In one or more embodiments of the negative electrode, the mesh-like structure of the porous current collector has a minimum mesh width extending between adjacent ones of the openings, wherein the minimum mesh width is less than 0.25 mm.

[0074] In one or more embodiments of the negative electrode, the mesh-like structure of the porous current collector has a minimum mesh width extending between adjacent ones of the openings, wherein the minimum mesh width is less than 0.15 mm.

[0075] In one or more embodiments of the negative electrode, the alkali metal foil has a thickness between 1 μm and 1000 μm.

[0076] In one or more embodiments of the negative electrode, the alkali metal foil has a width greater than 55 mm.

[0077] In one or more embodiments of the negative electrode, the negative electrode comprises multiple rows of alkali metal foil positioned in a closely spaced parallel arrangement through a porous current collector foil, wherein the width of the negative electrode is between 55 mm and 300 mm.

[0078] In one or more embodiments of the negative electrode, an alkali metal foil is laminated to a first side of a porous current collector foil, wherein the squeezed and flattened portion of the alkali metal foil is distributed along a second side of the porous current collector foil.

[0079] In one or more embodiments of the negative electrode, an alkali metal foil is laminated to a first side of a porous current collector foil, and wherein a second side of the porous current collector foil includes a coating of an alkali metal.

[0080] In one or more embodiments of the negative electrode, the coating is formed by one or more of vapor deposition, electrodeposition, slot die coating, dip coating, microgravure printing, flexographic printing, or plating during initial charging of a battery cell housing the negative electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] For the purpose of illustrating the present disclosure, the accompanying drawings show aspects of one or more embodiments of the present disclosure. However, it should be understood that the present disclosure is not limited to the precise methods and apparatus shown in the accompanying drawings, in which:

[0082] Figure 1 One embodiment of a battery cell of a secondary alkali metal battery is illustrated;

[0083] Figure 2 illustrates an exploded cross-sectional side view of an exemplary negative electrode constructed from a porous current collector and an alkali metal foil;

[0084] Figure 3 Picture shows Figure 2 An assembled cross-sectional side view of an exemplary negative electrode;

[0085] Figure 4 illustrates a cross-sectional side view of a current collector opening and an extruded portion of alkali metal;

[0086] Figure 5 illustrates another cross-sectional side view of a current collector opening and an extruded portion of alkali metal;

[0087] Figure 6 is a flow chart illustrating steps of an exemplary method of forming a porous current collector-alkali metal foil laminate for use as a negative electrode in a secondary metal battery;

[0088] Figure 7 An exemplary roll-to-roll system for lamination of carrier film and current collector metal foil is shown;

[0089] Figure 8 An exemplary rotary beer half-through roll-to-roll system is illustrated;

[0090] Fig. 9An arrangement of openings in a porous current collector resulting from a multi-step pore formation process is illustrated;

[0091] Fig.10 is a flow chart illustrating steps of an exemplary method for forming a porous current collector-alkali metal foil laminate for use as a negative electrode in a secondary metal battery;

[0092] Figures 11A-11F An exemplary embodiment of Fig.10 A cross-sectional side view of a structure formed during performance of the method illustrated in FIG.

[0093] Fig.12 An exemplary method that can be used to automate Fig.10 A reel-to-reel system of the method illustrated in FIG.

[0094] Fig.13 is an exploded side view of a first carrier film and a second carrier film and a current collector metal foil;

[0095] Fig.14 An exemplary roll-to-roll system for forming a laminate of porous current collector foil and first carrier film 1302 is illustrated;

[0096] Figures 15A-15G illustrates an exemplary hole pattern design for use in a porous current collector of the present disclosure;

[0097] Fig.16 The cycling performance of battery cells fabricated using various 8 μm thick perforated copper foil designs with 40 μm lithium foil laminated on one side is shown;

[0098] Fig.17 The cycling performance of battery cells fabricated using various 16 μm thick perforated copper foil designs with 40 μm lithium foil laminated on one side is shown;

[0099] Figures 18A-18C An exemplary perforated copper current collector is shown;

[0100] Figures 19A-19D shows an exemplary mesh pattern formed by a photolithography process;

[0101] Fig. 20 shows the cycling performance of battery cells fabricated using various perforated copper foil designs with 40 μm lithium foil laminated on one side;

[0102] Figures 21A-21B shows a porous titanium current collector fabricated by a photolithography process;

[0103] Fig.22A-C shows a computer simulation of lithium consumption at the edge of the mesh adjacent to a porous current collector in a negative electrode for three different mesh widths;

[0104] Fig.23A and 23B An embodiment of a wide negative electrode structure of the present disclosure is illustrated in which an alkali metal foil is laminated to only one side of a porous current collector;

[0105] Fig.23C An embodiment of a wide negative electrode structure of the present disclosure is illustrated in which an alkali metal foil is laminated to both sides of a porous current collector;

[0106] Fig.24A and 24B An exemplary wide-width negative electrode structure is illustrated in which multiple alkali metal foils are laminated to only one side of a porous current collector;

[0107] Fig.24C An exemplary wide-width negative electrode structure is illustrated in which multiple alkali metal foils are laminated to both sides of a porous current collector;

[0108] Fig.25 An exemplary vapor deposition system for applying an alkali metal to a current collector surface is illustrated;

[0109] Fig.26 An exemplary electrodeposition system for applying an alkali metal to a current collector surface is illustrated;

[0110] Fig. 27 illustrates an exemplary slot die coating system for applying an alkali metal to a current collector surface; and

[0111] Fig.28 A diagram of one embodiment of a computing device for causing a control system to perform aspects of the present disclosure is shown. DETAILED DESCRIPTION

[0112] Aspects of the present disclosure include alkali metal secondary batteries, including negative electrodes constructed from alkali metal foils applied to only one side of a porous current collector metal foil. The openings in the porous current collector allow alkali metal accessibility on both sides of the negative electrode structure, allowing efficient construction of batteries with multiple positive-negative electrode pairings. Such a negative electrode configuration makes it possible to utilize lower cost and more commonly available alkali metal foil thicknesses, such as a thickness greater than or equal to approximately 30 μm, while still achieving a high battery cell cycle life at a significantly reduced cost. Such a configuration also makes it possible to produce battery cells with larger area sizes, because thicker alkali metal foils are available in wider widths, such as a width greater than 55 mm. Such a configuration also increases the conductivity between the alkali metal foil and the current collector, thereby resulting in an increased high battery cell cycle life. Batteries with porous current collectors also have increased volume energy density and weight energy density.

[0113] Aspects of the present disclosure include methods for designing porous current collectors, such as to optimize the design of the current collector for a given application or performance metric, such as maximized cell cycle life. One design variable is the pore pattern of the current collector, such as selecting the pore pattern to maximize the alkali metal reach on both sides of the negative electrode while providing good electrical contact between the current collector and the alkali metal. Variables also include the shape of the pores, the size of the pores, the arrangement and spacing between the pores, the thickness of the current collector foil, and the area percentage of the openings in the current collector foil.

[0114] Figure 1 One embodiment of a battery cell 102 of a secondary alkali metal battery is illustrated. Figure 1 Only certain basic functional components of the battery cell 102 are shown. A practical implementation of the battery cell and / or battery will typically be embodied using a wound or stacked configuration, including components not shown for ease of illustration. Figure 1 Other components shown in the drawings, such as electrical terminals, seals, thermal breakdown layers and / or vents, among others. In the illustrated embodiment, the battery cell 102 includes a positive electrode 104 and a negative electrode 106 that are spaced apart, and a pair of corresponding respective current collectors 108, 110. A porous dielectric separator 112 is located between the positive electrode 104 and the negative electrode 106 to electrically separate the positive electrode and the negative electrode but allow metal ions such as lithium ions and ions of the electrolyte 114 to flow therethrough. The porous dielectric separator 112 and / or one, the other, or both of the positive electrode 104 and the negative electrode 106 may also be impregnated with the electrolyte 114. The battery cell 102 includes a container 116 that holds the components of the battery cell.

[0115] The positive and negative electrodes 104, 106 may include a variety of different structures and materials that are compatible with lithium metal ions and the electrolyte 114. Each of the current collectors 108, 110 may be made of any suitable conductive material, such as copper or aluminum, or any combination thereof. The porous dielectric separator 112 may be made of any suitable porous dielectric material, such as a porous polymer, among others.

[0116] The positive electrode 104 includes a positive electrode material 118, which can be formed of various materials known in the art, such as materials of the general formula LixMyOz, where M is a transition metal such as Co, Mn, Ni, V, Fe or Cr, and x, y, z are selected to meet valence requirements. In one or more embodiments, the positive electrode is selected from LiCoO 2 、Li(Ni 1 / 3 Mn 1 / 3 Co 1 / 3 ) 2 、Li(Ni 0.8 Co 0.15 Al 0.05 ) 2 、LiMn 2 O 4 、Li(Mn 1.5 Ni 0.5 ) 2 O 4 or a layered or spinel oxide material of the group consisting of lithium-rich forms thereof. In one or more embodiments, the positive electrode material is LiCoO 2 (charged to 4.4 V vs. Li metal), NCA or NCM (622, 811) (charged to 4.30 V vs. Li metal).

[0117] The negative electrode 106 may include a negative electrode material 120, such as a thin alkali metal foil, having a thickness in the range of 0 μm-1000 μm, 10 μm-100 μm, 30 μm-60 μm, or 20 μm-40 μm in a discharged state. Figure 1Negative electrode material 120 is schematically shown adjacent to current collector 110, but as described more below, a sheet or film of negative electrode material, such as an alkali metal, may be disposed on one or both sides of the current collector. In another embodiment, battery cell 102 may initially include only current collector 110, and an alkali metal, such as lithium, initially stored in positive electrode 104 is deposited on negative electrode current collector 110 during initial battery cell charging to form negative electrode 106. Further information about exemplary materials and constructions for battery cell 102 may be found in PCT Publication No. WO 2017 / 214276, entitled “High energy density, high power density, high capacity, and room temperature capable 'anode-free' rechargeable batteries”, which is incorporated herein by reference in its entirety.

[0118] Figure 2 and 3 An exploded cross-sectional side view and an assembled cross-sectional side view of an exemplary negative electrode 200 manufactured according to the present disclosure are illustrated, respectively. The negative electrode 200 includes a porous current collector 202 having a thickness tCC extending between a first side 206 and an opposite second side 208 and a mesh structure defining a plurality of openings 210 (only one is marked) extending from the first side to the second side. In some embodiments, the thickness tCC may be between 1 μm and 100 μm and between 4 μm and 20 μm in some embodiments. The negative electrode 200 also includes an alkali metal foil 204 having a thickness tMF. In some embodiments, the thickness tMF may be between 1 μm and 1,000 μm, and between 30 μm and 60 μm in some embodiments, and greater than 20 μm in some embodiments. The porous current collector 202 may be formed from any of a variety of materials, such as copper, nickel, titanium, and other refractory metals and alloys that are stable to the corresponding alkali metals such as lithium. The alkali metal foil may also be formed from any of a variety of materials, such as lithium, sodium, potassium, and the like.

[0119] As in Figure 2 As illustrated in FIG. 2 , negative electrode 200 may be formed by applying an alkali metal foil 204 to only one side, such as first side 206 , of porous current collector 202 by various processes described herein. Figure 3 Negative electrode 200 is illustrated in assembled form. Because alkali metal foil 204 is applied to first side 206, openings 210 of porous current collector 202 allow portions of the alkali metal to flow or squeeze through the openings. Figure 3An assembled negative electrode 200 is conceptually shown having a first portion 204a of an alkali metal foil 204 located on a first side 206 of a porous current collector, one or more second portions 204b located on a second side 208 of the current collector, and a third portion 204c of the alkali metal foil located in an opening 210 of the current collector. The first portion 204a has a thickness ta and the second portion 204b has a thickness tb, where ta+tb≈tMF. As described more below, the relative magnitudes of ta and tb can depend on the manufacturing techniques and desired design configuration variations used to assemble the negative electrode 200. For example, in some cases, tb can be approximately zero and the alkali metal foil 204 can be extruded only partially through the opening 210, or completely through the opening until the extruded portion of the alkali metal foil is substantially flush with the second side 208 of the current collector 202. In other embodiments, portions of the base metal foil 204 may be extruded beyond the second side 208 such that they protrude from the second side 208, and in certain embodiments, the extruded portions may then be distributed over the second side 208 of the current collector, forming a second portion 204b of the base metal foil 204. As will be appreciated, although Figure 3 The assembled negative electrode 200 is conceptually shown as having a substantially flat first side 302 and a second side 304, but in some embodiments, the second side 304 can have an undulating surface resulting from the extruded portions of the alkali metal foil 204 extending from each opening 210, and in some embodiments, the extruded portions are then distributed on the second side 208. As described more below, in some embodiments, the second side 208 can have a coating of an alkali metal, such as the same alkali metal as the alkali metal foil 204, to improve the uniformity of the alkali metal on the second side 208.

[0120] Figure 4 and 5 A cross-sectional side view of only one opening 210 of the current collector 202 is illustrated, showing two exemplary instantiations of the negative electrode 200. Figure 4 In the embodiment shown in , the base metal foil 204 has been extruded through the opening 210 until the end 402 of the extruded portion 404 is substantially flush with the second side 208 of the current collector 202 and the extruded portion 404 substantially fills the volume defined by the opening 210. Figure 4 In the embodiment shown in , the end 402 has a convex surface wherein a local maximum of the convex surface is flush or coplanar with the second side 208 and the convex surface and the opening 210 define a small volume 406 of open space therebetween. Figure 5 Similarly shown is an extruded portion 504 of the base metal foil 204, having an end 502 with a convex surface. Figure 5In the embodiment shown in , the alkali metal is squeezed further through the current collector 202 so that the end 502 protrudes and protrudes beyond the second side 208. In some embodiments, the end 502 can be flattened so that the end of the extruded portion 404 is substantially flat and flush with the second side 208. In some embodiments, Figure 5 The embodiment shown in FIG. 1 can provide a Figure 4 The embodiment shown in FIG. 1 shows a high battery cycle life performance due to the higher conductivity between the alkali metal and the current collector. In other embodiments, the second side 208 of the current collector 202 can be placed on a flat surface and the extrusion process is directed to Figure 4 The application of the embodiment shown in FIG. 4 can continue until the end 402 is flattened against the flat surface and from the Figure 4 The convex shape shown in FIG. 4 is converted to having a flat or planar end so that volume 406 is reduced or substantially eliminated.

[0121] Figure 6 An exemplary method 600 of forming a porous current collector-alkali metal foil laminate for use as a negative electrode in a secondary metal battery is illustrated. In step 603, method 600 may include laminating a carrier film to a metal foil, such as a copper metal foil. The carrier film may be formed from a variety of materials, such as polyesters, such as polyethylene terephthalate (PET), or any of a variety of other polymers, such as polyimide, polyethylene, polypropylene, polytetrafluoroethylene (PTFE), and the like. The carrier film may also be formed from a variety of metals, such as copper, nickel, and the like. In some embodiments, the thickness of the carrier film is greater than the thickness of the current collector (tCC) and may have a thickness in the range of 1 μm to 300 μm and in some embodiments between 25 μm and 250 μm and greater than 4 μm in some embodiments. The current collector metal foil may be attached to the carrier film by a pressure-sensitive or heat-sensitive low-viscosity adhesive on the carrier film. In some embodiments, step 603 may include activating a carrier film, such as a PET carrier film, by corona discharge and then coating the carrier film with an adhesive shortly thereafter. In one embodiment, the adhesive can be a low temperature heat sealable polyester resin dissolved in a solvent, such as Adcote 40-3E dissolved in ethyl acetate. In one embodiment, the coating is performed on the side of the corona activated carrier film using a No. 8 wet film applicator rod. The solvent is then removed by passing the film through a drying tunnel maintained at 200°F. A metal foil, such as an 8 μm thick copper foil, can then be laminated to the carrier film on the side coated with the adhesive. In one embodiment, the lamination includes moving the metal foil against a heated roller that is maintained, for example, above 180°F during lamination. The lamination of the carrier film and the metal foil can be automated, such as in a Figure 7 The exemplary roll-to-roll system 700 shown in FIG. Figure 7In the embodiment shown in , a roll 702 of metal foil 704 and a roll 706 of carrier film 708 can be fed through a laminating roller set 710 to laminate the two materials together. The laminating roller set can be heated to ensure good adhesion between the metal foil 704 and the carrier film 708. The laminated metal / carrier 712 can be guided by roller 714 and collected on roller 716. In other embodiments, instead of joining the carrier film and the current collector foil by lamination, the current collector can be formed directly on the surface of the carrier film by various processes, such as electrodeposition, chemical plating, etc., and the current collector can remain bonded to the carrier film, for example, by weak friction and / or electrostatic forces.

[0122] Refer again Figure 6 In step 605, holes can be formed in the laminated metal / carrier 712 using a hole forming process, such as a perforation process using an indexing mechanism to feed the laminate through a perforation head. In one embodiment, the perforation head has two rows of needles that perforate the laminate as it moves through the tool. In one embodiment, the metal foil being perforated is not under tension and is relaxed when it is fed through the perforation head. The carrier film is designed and configured to provide sufficient rigidity to the metal foil so that it can be fed through the perforation tool. The laminate can be oriented so that the perforation head enters and perforates both the metal and the carrier film on the metal foil side of the laminate. The carrier film also improves the quality of the holes formed in the metal foil, resulting in essentially defect-free holes, while holes formed in thin metal foils without a carrier may be more likely to include edge defects such as burrs, cracks, hole chips, and tears. In one embodiment, unpunched solid tape is left on the top and bottom edges of the roll for electrical labeling and ease of handling during downstream processes for preparing the final negative electrode structure. The perforations may have any of a variety of diameters, center-to-center distances, and patterns. For example, a diameter in the range of 0.1 mm to 3.0 mm, and in some embodiments 0.3 mm to 1.2 mm, a center-to-center distance of 0.15 mm to 3.5 mm, and in some embodiments 0.4 mm to 1.4 mm, and a hexagonally arranged hole pattern.

[0123] In another embodiment, at step 605, holes may be formed in the metal foil using a spinning beer half-penetration method. Figure 8One embodiment of a rotary beer semi-perforated roll-to-roll system 800 is illustrated, including a roll 802 of metal foil 804 and a roll 806 of carrier film 808 that can be fed through a rotary beer semi-perforated roller set 810. The rotary beer semi-perforated roller set 810 is configured and dimensioned to form holes only in the metal foil 804 and no holes in the carrier film 808, wherein the resulting metal foil fragments (also referred to as shavings) from the metal foil when the now perforated metal foil 812 and the carrier film 808 are delaminated or peeled off at roller set 814 remain attached to the low-tack adhesive side of the carrier film 808, wherein the metal shavings remain fixed to the carrier film 808, and the perforated metal foil 812 is collected on roller 816 and the carrier with the shavings is collected on roller 818. In one embodiment, the thickness of the metal foil 804 is less than 100 μm, and in some embodiments is between 4 μm and 20 μm, and in some embodiments is approximately 8 μm. The rotating beer half-through roller group is configured to stamp the metal foil 804 while reducing the chance that the foil will tear or bulge will be left on one side of the perforation. In addition, the low viscosity on the carrier film 808 ensures that the hole chips are removed with the carrier film, thereby preventing the hole chips from being retained on the perforated metal foil 812 and contaminating the negative electrode formed later.

[0124] As discussed more below, in certain embodiments, it may be desirable to increase the area of ​​the holes in a porous current collector relative to the total area of ​​the current collector, also referred to herein as the percent open area. However, in a punch or rotary punch machine, there is a limit to how closely the blades or needles can be spaced. Fig. 9 An exemplary approach for increasing the percent open area in a porous current collector using holes formed in an automated punching or rotary punching process is illustrated, despite minimum space requirements between adjacent pins or vanes. Fig. 9 The diagram illustrates an arrangement of openings 900 in a porous current collector resulting from a multi-step process in which a metal foil-carrier film laminate may be passed through a series of punching or rotating roller sets in which each subsequent roller set is offset from an adjacent roller set. Fig. 9An arrangement of openings 900 formed by multiple offset punch roller groups is shown, with cross-hatching used to indicate roller groups. In the illustrated embodiment, four offset and tandem roller groups with standard and commercially available pin spacing are used to create four groups of openings 900 labeled 902, 904, 906, and 908 (only one opening from each group is labeled). By way of non-limiting example, the minimum spacing between pins or blades of a standard rotary die can be 0.8 mm, which will result in a maximum of ~40% open area in a porous metal foil. By controlling the registration of the metal foil, subsequent processing on the same foil through offset punch roller groups with 0.8 mm spacing can result in greater than 60% open area with 0.2 mm spacing between holes.

[0125] Refer again Figure 6 , in step 607, the carrier film can be delaminated from the metal foil by peeling the metal foil from the carrier film. To prevent the metal foil from curling, substantially all of the peeling stress can be applied to the carrier film. This can be done by keeping the now perforated metal foil tensioned flat while flexing the carrier back approximately 180° in a sharp curl, which can be automated in a roll-to-roll conversion machine. In addition, in step 609, the perforated metal foil can be used to construct a negative electrode for battery applications by laminating an alkali metal foil to one or both sides, covering the holes. The lamination can be performed by a tumbling process. During lamination, the tumbling machine or other lamination process can be designed and configured to apply sufficient pressure to squeeze the alkali metal foil through the openings in the porous metal foil so that the alkali metal approximately or completely fills the holes of the perforated foil (e.g., as in Figure 4 and 5 ) to ensure good electrical contact between them. Discrete negative electrode blocks can then be punched out from the laminated strips and inspected for any edge defects. The negative electrode can then be assembled with the positive electrode, separator and electrolyte to make a battery.

[0126] Fig.10 Another exemplary method 1000 of forming a porous current collector-base metal foil laminate for use as a negative electrode in a secondary metal battery is illustrated. Figures 11A-11F provides a cross-sectional side view of an exemplary structure that may be formed during method 1000, and Fig.12 An exemplary roll-to-roll system that can be used in the automated method 1000 is illustrated. Fig.10 , at step 1003 , a current collector metal foil may be laminated to at least one carrier film and at step 1005 , holes may be formed in the current collector-carrier film laminate. Fig.11AAn exemplary current collector metal foil 1102 , such as copper, and a carrier film 1104 , such as PET, are illustrated, laminated together on a first side 1105 of the current collector foil 1102 to form a multilayer substrate in the form of a carrier film-current collector foil laminate 1106 . Fig. 11B A method is shown in which in step 1005 ( Fig.10 ) openings 1108 (only one is labeled) are formed in both the current collector foil 1102 and the carrier film 1104 , extending through the entire thickness of the laminate 1106 , forming an embodiment of a porous carrier film-current collector foil laminate 1107 .

[0127] Back to Fig.10 , the embodiment shown in FIGS. 11 and 12 does not include optional step 1007, which is discussed below. In step 1009 and also with reference to Fig. 11C , the alkali metal foil 1110 is laminated to only one side of the porous current collector-carrier film laminate 1107, here the second side 1111 of the current collector, to form the alkali metal foil-current collector foil-carrier film laminate 1112. The lamination process at step 1009 is sufficient to cause the alkali metal foil 1110 to flow or extrude through the openings 1108 to form extruded portions 1114 (only one is labeled). In the illustrated embodiment, the lamination process at step 1009 is sufficient to cause the ends 1116 of the extruded portions 1114 to extend beyond the first side 1105 of the current collector foil 1102, and in the illustrated embodiment, the ends 1116 are substantially flush with the second side 1118 of the carrier film 1104, which has a first side 1120 opposite the second side 1118 that contacts the first side 1105 of the current collector foil 1102.

[0128] The carrier film 1104 may have any of a variety of thicknesses tCF ( Fig.11A In certain embodiments, the thickness tCF of the carrier film 1104 is selectively configured according to the desired extrusion depth of the extruded portion 1114 of the alkali metal foil 1110. For example, for a given thickness tMF of the alkali metal foil, the thickness tCF can be greater than or equal to tMF / 2, so that the depth of the alkali metal foil extruded through the carrier film 1104 can be approximately equal to the remaining thickness ta of the alkali metal foil at the second side 1111 of the collector foil 1102 ( Fig. 11C In some embodiments, tCF may be selected to obtain a target total volume of the extruded portion 1114 that results in a thickness of the planarized extruded portion tPEP ( Fig.11F) is approximately equal to the remaining thickness ta of the alkali metal foil on the opposite side of the porous current collector 1102. In some embodiments, tCF can be selectively configured to obtain a target volume of the extruded portion 1114 that is approximately the same as the remaining volume of the alkali metal foil on the second side 1111 of the current collector 1102.

[0129] refer to Fig.10 and 11D At step 1011, method 1000 may include delaminating carrier film 1104 from current collector foil 1102, resulting in base metal foil-current collector metal foil laminate 1122, which includes extruded portion 1114 of base metal foil extending from first side 1105 of current collector foil 1102 and protruding from first side 1105 of current collector foil 1102. Fig.10 , 11E and 11F, at optional step 1013, in some embodiments, the extruded portion 1114 of the alkali metal can be removed by applying force 1130 ( Fig.11E ) is applied to the extruded portion and flattened on the first side 1105 of the collector foil 1102, resulting in an alkali metal-collector structure 1132 ( Fig.11F ), which includes an alkali metal distributed on both the first side and the second side 1111, 1105 of the porous collector foil 1102, for use as a negative electrode in a secondary metal battery. In other embodiments, step 1013 can be omitted. For example, the extruded portion 1114 can be formed in Fig.11D 1014 is left. In such an embodiment, the depth of the extrusion can be less than the depth of the extrusion when the planarization step 1013 is performed. If step 1013 is omitted, then the optional step 1015 of applying an alkali metal to the first side 1105 can be performed to ensure a relatively uniform layer of alkali metal over the entire surface of the first side 1105, including the spaces 1124 ( Fig.11D , only one is labeled). Any of a variety of processes may be used to apply the alkali metal to the side 1105, such as described below with reference to Figure 25-27 Any of the processes described, such as vapor deposition ( Fig.25 )、Electrodeposition( Fig.26 ), slot die coating, dip coating, micro gravure printing or flexographic printing ( Fig. 27). Such an additional process for applying a layer of alkali metal to first side 1105 of current collector 1102 can be performed after step 1011, or can be performed earlier, such as before or after step 1003. In some embodiments, the thickness tCF of carrier film 1104 and the resulting depth of extruded portion 1114 can be selected to be substantially the same as the thickness of the alkali metal coating applied in step 1015.

[0130] In yet other embodiments, the alkali metal coating is not applied to space 1124 during construction of the negative electrode and instead step 1015 is performed during initial charging of the battery cell by providing an initial amount of alkali metal ions in positive electrode 104 ( Figure 1 ) and metal ions are plated onto the space 1124 that accommodates the exposed collector.

[0131] Refer again Fig.10 , step 1017, which is substantially the same as step 1015, may be performed after step 1013 to apply a layer of alkali metal by, for example, vapor deposition, electrodeposition, slot die coating, or plating during the initial charge period before or after planarization of the extruded portion 1114. For example, after planarization in step 1013, the resulting alkali metal-current collector structure 1132 ( Fig.11F ) may still include portions of the bare current collector 1102 without a layer of alkali metal along the first side 1105. An additional layer of alkali metal may be applied to provide a uniform coating of alkali metal along the first side 1105.

[0132] Thus, by laminating the alkali metal foil 1110 to the collector foil 1102 while the carrier foil 1104 is still laminated to the collector metal foil, the extruded portion 1114 of the alkali metal foil can extend beyond the first side 1105 of the collector foil 1102, providing a volume of alkali metal on the first side 1105 of the collector, which can be flattened on the first side of the collector, resulting in a more equal distribution of the alkali metal on both the first and second sides 1105, 1111 of the collector.

[0133] Fig.12 The diagram illustrates a method that can be used to automate the method 1000 and create Figures 11A-11F1. An embodiment of a roll-to-roll system 1200 of the structure shown in FIG. The exemplary roll-to-roll system 1200 includes a roll 1202 of current collector foil 1102 and a roll 1206 of carrier film 1104, which may include any of the low-tack adhesives described herein to bond to the metal foil 1102, the foil 1102 and the film 1104 may be fed through a laminating roller set 1210 to laminate the two materials together, and the laminating roller set 1210 may be heated to ensure good adhesion between the current collector metal foil 1102 and the carrier film 1104. The current collector metal foil / carrier film laminate 1106 (see also Fig.11A ) can then be formed by openings 1108 in the laminate 1106 (see also Fig. 11B )'s punching machine 1214.

[0134] The now porous current collector metal foil / carrier film laminate 1107 can then be passed through a laminating roller set 1216 along with the base metal foil 1110 from a roll 1218 of base metal foil to form a base metal foil-current collector foil-carrier film laminate 1112 (see also Fig. 11C The laminating roller set 1216 may be heated and may be designed, configured, and controlled to apply a pressure sufficient to achieve a desired volume and / or extrusion depth of the extruded portion 1114 of the alkali metal ( Fig. 11C ), such as a target height of the extruded portion relative to the first side 1105 of the collector foil 1102. In one embodiment, the system 1200 may include an extrusion monitoring system 1220 for monitoring the extent of the extruded portion 1114 and providing feedback to the lamination roller group 1216 to control the temperature and / or applied pressure of the lamination roller group to control the extent of extrusion. The extrusion monitoring system 1220 may be configured to generate an extrusion feedback signal 1221 based on the determined extent of extrusion and configured to send the extrusion feedback signal to the lamination roller group 1216 to control the extent of extrusion. The extrusion monitoring system 1220 may include any of a variety of sensing mechanisms known in the art to monitor the extent of extrusion, such as a machine vision system configured to capture an image of the alkali metal foil-collector foil-carrier film laminate 1112, which may be configured to capture and process the image using a machine vision algorithm to determine whether the end 1116 of the extruded portion is below, above, or substantially flush with the second side 1118 of the carrier 1104 ( Fig. 11C ). In some embodiments, the extrusion monitoring system 1220 may include one or more contact or non-contact sensors used in conjunction with or in place of machine vision to determine the extent of extrusion.

[0135] The system 1200 also includes a porous carrier film roll 1222 for delaminating the porous carrier film 1224 from the base metal foil-collector metal foil laminate 1122 and collecting the porous carrier film 1224 for recycling or disposal. The system 1200 also includes a flattening roller group 1226 designed and configured to apply heat and / or pressure to flatten the extruded portion 1114 on the first side 1105 of the collector foil 1102. In one embodiment, the system 1200 may include a flattening monitoring system 1228 for monitoring the degree of flattening of the extruded portion 1114 and providing feedback to the flattening roller group 1226 to control the temperature of the flattening roller group or the pressure applied to control the flattening. The flattening monitoring system 1228 can be configured to generate a flattening feedback signal 1229 based on the determined degree of flattening and to send the flattening feedback signal to the flattening roller group 1226 to control the degree of flattening. The planarization monitoring system 1228 may include any of a variety of sensing mechanisms known in the art to monitor planarization, such as a machine vision system configured to capture images of the base metal foil-current collector foil laminate 1132, which may be configured to capture and process the images using a machine vision algorithm to determine whether the extruded portion 1114 has been sufficiently planarized to cover all or substantially all of the first side 1105 of the current collector foil 1102. In certain embodiments, the planarization monitoring system 1228 may include one or more contact or non-contact sensors used in conjunction with or in place of machine vision to determine the degree of planarization. In certain embodiments, the system 1200 may include a multi-stage sheeting machine (not shown) that may be used in place of or in conjunction with the laminating roller set 1216 and / or the planarizing roller set 1226.

[0136] Refer again Fig.10 and Fig.13 In certain embodiments, a plurality of carrier films are laminated to the current collector foil 1102 at step 1003. Fig.13In the embodiment shown in , the plurality of carrier films include a first carrier film 1302 having a low-viscosity adhesive layer 1303 and a second carrier film 1304 having a low-viscosity adhesive layer 1305, which, as described below, allows perforation of the collector foil 1102 and allows removal of the resulting metal pore chips by delaminating only the second carrier film 1304 from the metal foil 1102 and the first carrier film 1302 before lamination of the alkali metal foil to the collector. The first and second carrier films 1302, 1304 can have any of a variety of thicknesses. In certain embodiments, they have the same thickness. In other embodiments, the first carrier film 1302 can have a thickness that is selectively configured according to the desired extrusion depth of the alkali metal foil. For example, for a given thickness tMF of the alkali metal foil, the first carrier film 1302 can have a thickness tFCF greater than or equal to tMF / 2, so that the depth of the alkali metal foil extrusion through the first carrier film can be approximately equal to the remaining thickness of the alkali metal film on the opposite side of the collector metal foil. In some embodiments, tFCF may be selected to obtain a target volume of extruded portion 1114 ( Fig. 11C ), the target volume results in the thickness of the flattened extruded portion tPEP ( Fig.11F ) is approximately equal to the remaining thickness ta of the alkali metal foil on the opposite side of the porous current collector 1102. The thickness tSCF ( Fig.13 ) may be different from the thickness tFCF of the first carrier film 1302 and may be greater than or equal to the tack 1424 ( tFCF ) used to remove the current collector foil 1102 and the first carrier film 1302 during delamination of the second carrier film. Fig.14 ), as described below. In some embodiments, the thickness tFCF of the first carrier film 1302 may be between 1 μm and 300 μm, and in some embodiments between 25 μm and 250 μm, and in some embodiments greater than 4 μm. In some embodiments, the thickness tSCF of the second carrier film 1304 may be between 1 μm and 500 μm, and in some embodiments between 25 μm and 250 μm, and in some embodiments greater than 4 μm.

[0137] Refer again Fig.10 , at steps 1005 and 1007, method 1000 may include forming holes in the current collector metal foil / multiple carrier film laminate (step 1005) and then delaminating one of the carrier films to remove waste material. Fig.14 An exemplary roll-to-roll system 1400 for automatically performing steps 1003 to 1007 is illustrated. Fig.14, system 1400 includes a current collector metal foil roll 1402 for providing a current collector foil 1102 and a first carrier film roll 1404 for providing a first carrier film 1302, which can be formed from any of the materials described herein and has a low-tack surface 1303, such as any of the carrier films described herein. System 1400 includes a lamination roller set 1406 for performing the first portion of step 1003 and laminating the current collector foil 1102 and the first carrier film 1302 to form a multilayer substrate in the form of a current collector metal foil-first carrier film laminate 1405. System 1400 also includes a second carrier film roll 1408 for providing a second carrier film 1304, and a lamination roller set 1410 for performing the second portion of step 1003 and laminating the second carrier film 1304 to the current collector metal foil first carrier film laminate 1405 to form a multilayer substrate in the form of a current collector metal foil-first carrier film-second carrier film laminate 1412. The system 1400 also includes a hole forming roller set 1414 for performing step 1005 to form holes in the laminate 1412. In the illustrated embodiment, the hole forming roller set 1414 is a rotating beer semi-piercing roller set with cutting elements, and the cutting elements are designed and configured to form holes that extend only through the collector foil 1102 and the first carrier film 1302 and do not extend through the second carrier film 1304, so that the resulting hole cuttings 1424 of the collector metal foil and the first carrier film are pressed against and adhered to the second carrier film for removal. The system 1400 also includes a roller set 1416, which is used to collect the porous collector foil and first carrier film 1302 laminate 1420 for downstream steps such as steps 1009-1017 ( Fig.10 ) and roller 1422 for collecting the second carrier film 1304 and the pores 1424 of the collector metal foil 1402 and the first carrier film 1302 formed by the pore forming roller group 1414. Roller group 1416 and rollers 1418 and 1422 cooperate to perform step 1007, delaminating at least one carrier film, such as the second carrier film 1304, from the collector metal foil / first carrier film laminate 1420. Therefore, system 1400 can be used instead of components 1202, 1206, 1210 and 1214 of system 1200 to prepare a porous current collector foil and first carrier film 1302 laminate 1420 that can be laminated to an alkali metal foil, for example, as described in reference Fig.12 and Fig.10 as described in steps 1009-1017.

[0138] Porous current collector design

[0139] The openings in the porous metal foil allow for alkali metal accessibility on both sides of the negative electrode structure, despite having been laminated to only one side of the current collector metal foil. The hole pattern on the current collector metal foil can be optimized to allow unimpeded alkali metal access on both sides of the negative electrode while providing good electrical contact, thereby increasing the battery cell cycle life. Exemplary variables that can be fine-tuned to create an optimal hole design include 1) the shape of the holes, 2) the size of the holes, 3) the arrangement and spacing between the holes, and 4) the thickness of the porous foil. The shape, size, and spacing between the holes also determine the open area, i.e., the percentage of the area of ​​the current collector foil occupied by the holes.

[0140] In one embodiment, tests conducted by the inventors of the present invention indicate that the optimal hole pattern includes circular or polygonal holes with a maximum width in the range of 0.1 mm to 3 mm and in some embodiments 0.3 mm-1.5 mm and in some embodiments 1 mm-1.5 mm and in some embodiments greater than approximately 0.5 mm. The holes or openings can be placed in a close-packed arrangement to give a percentage open area occupied by openings in the range of 30%-99% and in some embodiments 40%-80% and in some embodiments 60%-90% and in some embodiments above 50% and in some embodiments greater than 80%, based on 100% of the total area of ​​the collector, but excluding any non-porous areas of the collector, such as non-porous bosses or bands above or below the porous areas that can be used for convenient electrical labeling or manipulation. The minimum line width (also referred to as the mesh width) of the resulting mesh is less than 0.25 mm and in some embodiments less than 0.15 mm. The thickness of the perforated foil can be between 4 and 20 μm. The alkali metal may be applied to one or both sides of the porous current collector using any of the methods disclosed herein, resulting in a thickness of alkali metal on each side of the current collector in the range of 0 μm-100 μm, and in certain embodiments 0 μm-50 μm.

[0141] Figures 15A-15G Exemplary hole pattern designs including various hole shapes (circular, hexagonal) and sizes (0.3mm, 0.75mm, 1.2mm) are illustrated. The holes are compactly arranged in a triangular pitch and the spacing between the holes is adjusted to obtain the desired open area percentage (40%, 55%, 70%, 80%). The holes punched in the metal foil are traditionally round (circular or oval) holes without sharp corners for easy tool maintenance. However, circular holes can form perforation patterns with uneven mesh widths (line widths) and limit the degree to which the holes can be arranged tightly. In comparison, polygonal holes (triangles, squares, hexagons, etc.) provide a more compact arrangement with a smaller mesh width in the perforation pattern.

[0142] Table 1 (below) lists the test results from an exemplary design, and the corresponding mass and thickness of the negative electrode made by laminating a 40 μm thick lithium layer on one side of the perforated sample, where the lithium metal substantially fills the openings in the porous current collector, but extrusion does not exist on the opposite side. Table 1 also lists the cycle life performance of the battery cell made using the negative electrode of the present disclosure, as well as the cycle life performance of the conventional Li / Cu / Li negative electrode. As can be seen in Table 1, for the same total lithium thickness, the negative electrode made using the perforated copper foil is lighter and thinner than the corresponding conventional Li / Cu / Li negative electrode. This reduction in the mass and thickness of the negative electrode leads to higher weight energy density and volume energy density of the battery cell. Because copper can be denser than lithium, perforated foils with 70% and higher open areas reduce the mass of the negative electrode by up to 50%, compared with conventional Li / Cu / Li structures. Even if the perforated copper is 16 μm thick, there can be a significant reduction of more than 30% in weight. The perforated current collector also reduces the resulting negative electrode thickness. Because lithium is a soft metal, it squeezes out under pressure during lamination and fills the holes on the perforated foil, resulting in a thinner negative electrode. For example, laminating 40 μm lithium on one side to an 8 μm perforated foil with 70% open area results in a negative electrode with a thickness of 43 μm, as opposed to 48 μm (Table 1).

[0143] Table 1

[0144]

[0145] Fig.16 The cycling performance of battery cells fabricated using various 8μm thick perforated copper foil designs with 40μm lithium foil laminated on one side are shown. The cycling performance of the battery cells tends to improve with increasing hole size and open area. For example, in the battery cells with perforated designs with circular holes, the 1.2mm size with 70% open area showed the best cycling performance. In addition, the battery cells with hexagonal holes were found to show relatively better performance than circular holes.

[0146] Fig.17 The cycling performance of battery cells made using various 16μm thick perforated copper foil designs with 40μm lithium foil laminated on one side is shown. The cycling performance of the battery cell with 16μm perforated copper can be better than the 8μm sample with a similar hole pattern. This may be due to better electrical contact with the laminated lithium (the thicker 16μm perforated copper is embedded deeper inside the lithium foil), which increases lithium utilization in the battery cell. Using copper foil with higher thickness (25μm or higher) may negate any weight and volume benefits of perforation, compared with conventional negative electrodes.

[0147] Similar to the 8μm samples, the 16μm samples also showed improved cycling performance with an increase in pore size and open area. Cells with hexagonal pores were also found to show relatively better performance than circular pores. For example, a cell design with 1.2mm hexagonal pores and 80% open area showed the same cycling performance as the conventional Li / Cu / Li anode ( Fig.17 ).

[0148] The improvement in battery cell performance using hexagonal holes can be due to the thinner and uniform mesh width in the perforation pattern, which reduces polarization and promotes uniformity of lithium consumption in the negative electrode. The compact hole arrangement and fixed mesh width in the perforation design can also be obtained using other polygonal shapes, such as squares, triangles, pentagons, etc. Table 1 also lists the corresponding mesh width for each hole pattern. Table 1 indicates that a mesh width of less than 0.25 mm or less than 0.15 mm of the perforation design results in higher cycling performance.

[0149] As mentioned above, in Table 1 and Fig.16 and 17 The test data shown in is from a negative electrode having an alkali metal that substantially fills the openings in the porous current collector, but extrusion of the alkali metal is absent. In such a configuration, it may be more important to maximize the percent open area of ​​the current collector to increase alkali metal utilization. As a comparison, for a negative electrode using reference Fig.10 For negative electrodes constructed using various methods discussed, high cycling performance may be achievable using a porous current collector having a lower percent open area because the squeezed-out portion of the alkali metal enables greater distribution of the alkali metal on both sides of the current collector, resulting in improved electrical contact and increased alkali metal utilization. Thus, a method of designing a porous current collector may include the steps of determining the amount of alkali metal that will be located on both sides of the current collector, and then determining the corresponding minimum % open area of ​​the current collector to achieve a target cell performance metric, such as cell cycle life.

[0150] Refer again Figure 4 and 5, the extent of lamination between the perforated current collector 202 and the alkali metal foil 204 is schematically shown. During lamination, the applied pressure and temperature affect the extent to which the alkali metal squeezes out and fills or approximately fills the openings 210 of the porous current collector 202. Tests performed by the inventors of the present invention indicate that in certain embodiments, a greater extent of alkali metal squeeze out and filling of the openings 210 with alkali metal improves battery cell cycling performance, which may be due to improved electrical contact between the alkali metal and the current collector. The alkali metal foil 204 extruded inside the opening 210 may have an end 402 having a convex surface, which may be at the level of the current collector surface or may protrude to a certain extent.

[0151] In certain embodiments, the porous current collector can be manufactured by electroforming or photoetching by a photolithography process. Such a process can allow the production of perforated metal foils with high open areas and thinner and uniform mesh widths, as compared with punching processes. Typically, photolithography processes make it possible to produce perforated foils with an open area of ​​up to 90% or more. High open areas allow for uniform alkali metal accessibility on both sides of the negative electrode laminate constructed using an alkali metal foil on one side. Photolithography processes allow the production of porous metal foils with almost any hole shape. For example, any polygonal hole (triangle, square, pentagon, hexagon, etc.) can be manufactured. Compared with circular or elliptical hole patterns, polygons can be arranged more compactly to achieve higher open areas and uniform mesh widths. Photolithography processes allow the production of perforated patterns with mesh widths narrower than circular holes. For example, the minimum spacing between holes can be less than 0.2 mm, which is the typical minimum spacing required for conventional punching processes, and can be as low as, for example, 0.05 mm. Narrow mesh widths generally allow for perforation designs with higher open areas and greater alkali metal accessibility.

[0152] Photolithography is a standard technique used in the manufacture of parts for microelectronic devices. In the photolithography process, a photoresist is coated on a substrate and a subsequent image is exposed. The workpiece is developed to remove the unexposed photoresist and the exposed photoresist is used to mask the area corresponding to the mesh pattern on the surface of the thin foil. The workpiece is then exposed to a metal selective etchant to etch away the metal not covered by the photoresist. The remaining photoresist is then removed in subsequent steps, leaving a patterned workpiece. In the electroforming process, a mask is applied to a mandrel in the area corresponding to the holes in the mesh, and a collector foil is electrodeposited in the gap to make the mesh.

[0153] Fig.18A and 18BA perforated copper current collector fabricated by electroforming is shown, having an open area of ​​80% formed by a close arrangement of hexagonal holes. In comparison, circular holes of the same size and arrangement, such as in Fig.18C As shown in , resulting in 72% open area. Fig.18B and 18C The mesh pattern formed by hexagonal and circular holes is shown. As is apparent from the image, the mesh width between the hexagons is thinner and more uniform than the circular holes, allowing for a high open area.

[0154] Figures 19A-20 and Table 2 illustrates the above reference Figure 1 A subset of negative electrodes was tested as described to emphasize the effect of pore shape on mesh width and percent open area. Figures 19A-19D An exemplary mesh pattern formed by a photolithography process is shown, including circular and hexagonal holes with sizes of 0.75 mm and 1.2 mm and open areas between 55% and 80%. Table 2 lists the mesh widths of the above hole patterns and the battery cells ( Fig. 20 ) The corresponding cycle life is obtained from the cell cycle performance is proportional to the percent open area and inversely proportional to the mesh width of the perforation pattern. Fig. 20 The negative electrode use process 600 ( Figure 6 ) is manufactured in step 609, wherein the lithium metal substantially fills the openings in the porous current collector, but extrusion does not exist on the opposite side. Table 2 lists the Figures 19A-19D The mesh width of the hole pattern illustrated in FIG. 1 and the corresponding cycle life measured in testing of battery cells incorporating the illustrated current collectors. Fig. 20 The cycle life performance data listed in Table 2 are shown in the figure. Table 2 and Fig. 20 The cycling performance of the indicated battery cell is directly proportional to the percent open area and inversely proportional to the mesh width of the perforation pattern. Fig.16 and 17 As mentioned, the cycling performance for smaller % open area current collectors can be improved by using the method 1000 ( Fig.10 ) was added.

[0155] Table 2

[0156]

[0157]

[0158] Figures 21A-21BA porous titanium current collector fabricated by a photolithography process is shown, with -90% open area. The high open area obtained is a result of the tightly packed square pores with a mesh width of 0.05 mm, which was obtained by the photolithography process.

[0159] Figures 22A-22C The results for three different mesh widths (0.1 mm) are shown. Fig.22A )、0.2mm( Fig. 22B ) and 0.3mm( Fig. 22C ) in a negative electrode having a perforated current collector and using method 600 ( Figure 6 ) is laminated on one side of the negative electrode of lithium adjacent to the edge of the mesh during cycling over time, where the lithium metal substantially fills the openings in the porous current collector, but squeeze-out does not exist on the side of the porous current collector. The width of the mesh on the side of the negative electrode with the porous current collector is shown to affect the uniformity of lithium consumption. In essence, if the mesh width is thinner, the lithium consumption is more uniform, which leads to better lithium utilization and longer cycle life of the battery.

[0160] The present disclosure includes various methods for the construction and manufacture of perforated metal foils including as current collectors and the lamination of alkali metal foils to only one side of the perforated foil to produce a negative electrode. The openings in the current collector foil allow alkali metal accessibility on both sides of the negative electrode structure. These methods enable the utilization of more commonly available alkali metal foils for negative electrode production, such as lithium foils, such as foils having a thickness greater than or equal to 30 μm, with substantially the same resulting negative electrode thickness, as compared to conventional approaches that apply thinner alkali metal foils to both sides of the current collector. As a non-limiting example, a 40 μm thick lithium foil can be laminated to only one side of an 8 μm perforated copper foil to produce a negative electrode, the resulting thickness of which is similar to or lower than a conventional Li / Cu / Li negative electrode having a thickness of 20 / 8 / 20 μm. Such an approach also enables the production of battery cells with larger area sizes because it utilizes more commonly available and easily manufactured alkali metal foils having a thickness of 30 μm or more, which are also available in wider roll widths (e.g., up to 200 mm). The negative electrode of the present disclosure also increases the gravimetric and volumetric energy density of the battery cell because the openings in the current collector reduce the mass and volume associated with the typically high density current collector foil.

[0161] By way of example, in the prior art secondary lithium battery manufacturing process, lithium foil (active material) is laminated to both sides of copper foil (collector) to form a conventional (Li / Cu / Li) negative electrode. For example, ~20μm thick lithium foil is laminated to both sides of ~8μm copper foil. However, because lithium can be soft and sticky, it can be difficult to produce lithium foil with a thickness of ~25μm or less by a conventional rolling process. In contrast, using one or more of the methods disclosed herein, a perforated foil can be used as a collector and lithium can be laminated to only one side of the perforated foil. The perforations on the collector allow lithium to be reached on both sides of the negative electrode structure. The present disclosure makes it possible to use a commonly available lithium foil with a thickness of 30μm or more for negative electrode manufacturing. For example, a 40μm thick lithium foil laminated to one side of a perforated copper foil can be used as a negative electrode.

[0162] In a non-limiting embodiment, the perforated copper foil is manufactured by one of the methods disclosed herein. The width of the roll of the perforated current collector foil may be higher than 60 mm or 70 mm. The percentage open area of ​​the perforated foil may be higher than 40% or 60%. Unpunched solid tape may be left on the top and bottom edges of the roll for convenience of electrical contact and manipulation. The thickness of the perforated copper foil may be between 4 μm and 20 μm. The perforated copper is then laminated with lithium foil on only one side, covering the holes, to make a negative electrode for battery applications. The width of the lithium foil may be substantially the same as or slightly wider than the perforated portion of the copper foil. The thickness of the lithium foil may be between 30 μm and 60 μm. In one embodiment, an 8 μm thick perforated copper foil having a width of approximately 75 mm perforated strips or areas and 65% open area may be used. The perforated copper foil is laminated with a 77 mm wide 40 μm thick lithium foil on one side, covering the holes. Lamination can be performed using any of the methods and systems disclosed herein, such as using a tumbler process in which the tumbler pressure is set so that the lithium squeezes out and nearly or completely fills the holes of the perforated copper to ensure good electrical contact and high lithium accessibility on the copper side.

[0163] Discrete negative electrode blocks can then be punched out of the laminated copper-lithium strips and inspected for any edge defects. The negative electrode is then assembled with the positive electrode, separator and electrolyte to make a lithium battery. Perforated copper makes it possible to have a negative electrode with single-sided lithium lamination because the perforations allow lithium to be accessed on both sides of the electrode. Because copper can be denser than lithium, perforated copper also significantly reduces the negative electrode mass and increases the specific energy of the battery.

[0164] The photolithography process enables the production of discrete current collector parts with customized sizes and hole patterns with high open areas. By way of example, a ~90 mm wide perforated titanium current collector made by a photoetching process with ~90% open area can be constructed. Compared with a 60 mm wide conventional lithium negative electrode, the negative electrode with a perforated current collector allows the production of battery cells with larger area sizes. A soft pack battery cell manufactured using a 90 mm wide negative electrode is typically 3 to 4 times larger than a battery cell manufactured using a conventional negative electrode. Therefore, a perforated current collector with lithium laminated to one side allows for more flexible battery cell sizes, as well as higher compression and energy density at the compression level.

[0165] The perforated current collector of the present disclosure can be made using any metal suitable for alkali metal battery cells, such as copper, titanium, nickel, and other refractory metals and alloys that are stable for a given alkali metal such as lithium. The perforated current collector of the present disclosure can be made by any of a variety of processes, such as manual punching, rotary punching, electroforming, photoetching, laser cutting, and the like. The perforated current collector can also be made by flattening a woven, non-woven, or expanded metal mesh that can be formed in a metal mesh weaving or forming process. In certain embodiments, the perforated current collector of the present disclosure may have a thickness ranging from 4 to 20 μm or more. The perforated current collector of the present disclosure can also be used in battery cells having alkali metals other than lithium as negative electrode active materials, such as sodium, potassium, and the like.

[0166] Fig.23A and 23B An exemplary wide negative electrode 2300 of the present disclosure is illustrated, comprising an alkali metal foil 2302 laminated to only one side 2304 of a porous current collector 2306 having a plurality of openings 2308 (only one is labeled). By laminating the alkali metal foil 2302 to only one side, a thicker alkali metal foil can be used while still resulting in a lower overall thickness of the negative electrode. By utilizing a porous current collector 2306, the openings 2308 allow access to the alkali metal 2302 from a second side 2314 of the current collector. Fig.23C A cross-section of a second embodiment of a wide negative electrode 2310 is shown, which is the same as negative electrode 2300, except that negative electrode 2310 includes a second base metal foil 2312 laminated to a second side 2314 of current collector 2306. In other embodiments, negative electrode 2300 or 2310 can have a solid non-porous current collector that does not include opening 2308. As shown in Fig. 23B and 23CAs shown in FIG. 2 , the alkali metal foils 2302 and 2312 can have a thickness from 0 μm to 1000 μm and a width from 55 mm to 300 mm or more. Such a negative electrode structure allows the production of secondary alkali metal batteries with large battery cell sizes that can be used to meet the energy needs of various applications, including consumer electronic devices, commercial / recreational drones, and electric vehicle applications.

[0167] Fig.24A and 24B An exemplary wide-width negative electrode 2400 formed by parallel lamination of multiple lithium ribbons 2402, 2404 is illustrated, having a lithium width between 55 and 300 mm or greater, each having a width of less than, for example, 55 mm. For example, to make an 80 mm wide lithium negative electrode 2400, two lithium ribbons 2402, 2404 of width 50 mm and 30 mm, respectively, can be laminated side by side to a first side 2406 of a porous current collector foil 2408 in a closely spaced parallel arrangement across the porous current collector foil to form the wide-width negative electrode. The gap 2410 between the laminated lithium ribbons 2402, 2404 can be small, for example less than 0.5 mm, to maximize uniform alkali metal availability to the adjacent positive electrode. Fig.24C An exemplary negative electrode 2420 is shown that is identical to negative electrode 2400, except that two lithium ribbons 2422 and 2424 are also laminated to second side 2426 of current collector 2408. In other embodiments, negative electrodes 2400 or 2420 can be formed using a solid, non-porous current collector that does not include openings.

[0168] Negative electrode structures with thin alkali metal layers, for example with a thickness below 30 μm, and large widths, for example between 55 mm and 800 mm or more, can be manufactured in a roll-to-roll process by vapor deposition of the alkali metal on a current collector metal substrate, as in Fig.25 2502. As shown, the alkali metal can be melted in a crucible 2502 under a partial pressure or inert atmosphere, and the vapor 2504 deposited on the collector foil 2506 can be maintained above the crucible. The alkali metal vapor solidifies upon deposition on the collector substrate, and in some embodiments, the process is repeated on the other side of the collector foil. The thickness of the deposited alkali metal is determined by the duration of exposure to the vapor (roll speed) and the width of the deposited alkali metal is determined by the size of the crucible opening to the substrate.

[0169] Negative electrode structures with thin alkali metal layers, for example with a thickness below 30 μm and large widths, for example between 55 mm and 800 mm or more, can also be produced in a roll-to-roll process by electrodeposition of the alkali metal on the current collector substrate, as in Fig.2626. The electrodeposition of alkali metal on the collector foil substrate 2602 can be carried out in an electrochemical cell 2604 containing an alkali metal 2606 as a positive electrode, a collector foil substrate 2602 as a negative electrode, and an electrolyte 2608 that conducts alkali metal ions. The electrolyte 2608 that conducts alkali metal ions can be made, for example, by dissolving an alkali metal salt in an anhydrous solvent. The thickness of the deposited alkali metal on the collector foil substrate 2602 is determined by the current density and the duration of exposure to the electrolyte, and the width of the deposited alkali metal is determined by the width of the collector substrate exposed to the electrolyte.

[0170] Negative electrode structures with thin alkali metal layers, such as thicknesses below 30 μm and large widths, such as between 55 mm and 800 mm or more, can also be manufactured by coating molten alkali metal on a current collector substrate. The molten alkali metal 2702 can be coated on the current collector foil substrate 2704 by a variety of roll-to-roll processes, such as slot die coating, dip coating, micro gravure printing, and flexographic printing. Fig. 27 A schematic diagram of slot die coating of molten alkali metal on a current collector substrate is shown. In the illustrated process, molten alkali metal 2702, such as lithium, is injected through a die head 2706 and coated on one side of a current collector foil substrate 2704. The alkali metal solidifies upon coating on the substrate and the process can be repeated on the other side of the current collector foil. The thickness of the coated alkali metal on the current collector substrate is determined by the injection pressure and the roll speed and the width of the coated alkali metal is determined by the die head.

[0171] As mentioned above, in embodiments where an alkali metal foil is laminated to only one first side of the porous current collector, a second, opposite side of the porous current collector may be coated with an alkali metal using any coating process known in the art, including reference to Figure 25-27 Any of the described and illustrated coating processes, such as during steps 1015 and / or 1017 ( Fig.10 ). In other embodiments, an alkali metal foil may be laminated to both sides of any of the porous current collectors disclosed herein.

[0172] Any one or more of the aspects and embodiments described herein can be conveniently implemented using one or more machines programmed according to the teachings of the present invention (e.g., one or more computing devices used as user computing devices for electronic files, one or more server devices, such as file servers, etc.), as will be apparent to those skilled in the computer arts. Suitable software coding can be readily prepared by skilled programmers based on the teachings of the present disclosure, as will be apparent to those skilled in the software arts. The aspects and implementations of the use of software and / or software modules discussed above may also include suitable hardware for the implementation of machine-executable instructions of the auxiliary software and / or software modules.

[0173] Such software can be a computer program product using a machine-readable storage medium. A machine-readable storage medium can be any medium capable of storing and / or encoding a sequence of instructions for being executed by a machine (e.g., a computing device) and causing the machine to execute any one of the methods and / or embodiments described herein. Embodiments of machine-readable storage media include, but are not limited to, disks, optical disks (e.g., CDs, CD-Rs, DVDs, DVD-Rs, etc.), magneto-optical disks, read-only memory "ROM" devices, random access memory "RAM" devices, magnetic cards, optical cards, solid-state memory devices, EPROMs, EEPROMs, and any combination thereof. Machine-readable media, as used herein, is intended to include a single medium and a collection of physically separated media, such as a collection of optical disks or one or more hard disk drives combined with a computer memory. As used herein, a machine-readable storage medium does not include signal transmission in an instantaneous form.

[0174] Such software may also include information (e.g., data) carried as a data signal on a data carrier, such as a carrier wave. For example, machine-executable information may be included as a data-bearing signal embodied in a data carrier, in which the signal encodes a sequence of instructions or a portion thereof for execution by a machine (e.g., a computing device) and any related information (e.g., data structures and data) that causes the machine to perform any of the methods and / or embodiments described herein.

[0175] Examples of computing devices include, but are not limited to, electronic book reading devices, computer workstations, terminal computers, server computers, handheld devices (e.g., tablet computers, mobile phones, etc.), network devices, network routers, network switches, network bridges, any machine capable of executing a sequence of instructions specifying actions to be taken by the machine, and any combination thereof. In one embodiment, the computing device may include and / or be included in a self-service terminal.

[0176] Fig.28A diagram of one embodiment of a computing device in the exemplary form of a computer system 2800 is shown within which a control system such as a Fig.12 The roll-to-roll system 1200 system may be executed by a set of instructions that perform any one or more of the aspects and / or methods of the present disclosure. It is also contemplated that multiple computing devices may be utilized to implement a set of instructions that are specifically configured to cause one or more of the devices to perform any one or more of the aspects and / or methods of the present disclosure. The computer system 2800 includes a processor 2804 and a memory 2808 that communicate with each other and with other components via a bus 2812. The bus 2812 may include any of a variety of types of bus structures, including but not limited to a memory bus, a memory controller, a peripheral bus, a local bus, and any combination thereof, using any of a variety of bus architectures.

[0177] The memory 2808 may include various components (e.g., machine-readable media), including, but not limited to, random access memory components, read-only components, and any combination thereof. In one embodiment, a basic input / output system 2816 (BIOS), including basic routines that help transfer information between elements within the computer system 2800, such as during startup, may be stored in the memory 2808. The memory 2808 may also include (e.g., stored on one or more machine-readable media) instructions (e.g., software) 2820 that embody any one or more of the aspects and / or methods of the present disclosure. In another embodiment, the memory 2808 may also include any number of program modules, including, but not limited to, an operating system, one or more application programs, other program modules, program data, and any combination thereof.

[0178] The computer system 2800 may also include a storage device 2824. Embodiments of storage devices (e.g., storage device 2824) include, but are not limited to, hard disk drives, disk drives, optical disk drives combined with optical media, solid-state memory devices, and any combination thereof. The storage device 2824 may be connected to the bus 2812 by a suitable interface (not shown). Exemplary interfaces include, but are not limited to, SCSI, Advanced Technology Attachment (ATA), Serial ATA, Universal Serial Bus (USB), IEEE 1394 (FIREWIRE), and any combination thereof. In one embodiment, the storage device 2824 (or one or more of its components) may be removably interfaced with the computer system 2800 (e.g., via an external port connector (not shown)). In particular, the storage device 2824 and the associated machine-readable medium 2828 may provide non-volatile and / or volatile memory for machine-readable instructions, data structures, program modules, and / or other data for the computer system 2800. In one embodiment, the software 2820 may reside entirely or partially in the machine-readable medium 2828. In another embodiment, the software 2820 may reside completely or partially within the processor 2804 .

[0179] The computer system 2800 may also include an input device 2832. In one embodiment, a user of the computer system 2800 may enter commands and / or other information into the computer system 2800 via the input device 2832. Examples of the input device 2832 include, but are not limited to, an alphanumeric input device (e.g., a keyboard), a pointing device, a joystick, a joystick, an audio input device (e.g., a microphone, a voice response system, etc.), a cursor control device (e.g., a mouse), a touch pad, an optical scanner, a video capture device (e.g., a still camera, a video camera), a touch screen, and any combination thereof. The input device 2832 may be connected to the bus 2812 via any of a variety of interfaces (not shown), including but not limited to a serial interface, a parallel interface, a game port, a USB interface, a FIREWIRE interface, a direct interface to the bus 2812, and any combination thereof. The input device 2832 may include a touch screen interface, which may be part of or separate from the display 2836, discussed further below. The input device 2832 may be utilized as a user selection device for selecting one or more graphical representations in a graphical interface, as described above.

[0180] The user can also enter commands and / or other information into the computer system 2800 via a storage device 2824 (e.g., a removable disk drive, a flash drive, etc.) and / or a network interface device 2840. A network interface device such as the network interface device 2840 can be used to connect the computer system 2800 to one or more of various networks, such as a network 2844 and one or more remote devices 2848 connected thereto. Embodiments of network interface devices include, but are not limited to, network interface cards (e.g., mobile network interface cards, LAN cards), modems, and any combination thereof. Embodiments of networks include, but are not limited to, wide area networks (e.g., the Internet, enterprise networks), local area networks (e.g., networks associated with offices, buildings, campuses, or other relatively small geographic spaces), telephone networks, data networks associated with telephone / voice providers (e.g., mobile communications provider data and / or voice networks), direct connections between two computing devices, and any combination thereof. Networks such as the network 2844 can employ wired and / or wireless communication modes. Generally, any network topology can be used. Information (eg, data, software 2820 , etc.) may be communicated to and / or from computer system 2800 via network interface device 2840 .

[0181] The computer system 2800 may also include a video display adapter 2852 for communicating a displayable image to a display device such as a display device 2836. Embodiments of display devices include, but are not limited to, liquid crystal displays (LCDs), cathode ray tubes (CRTs), plasma displays, light emitting diode (LED) displays, and any combination thereof. Display adapter 2852 and display device 2836 may be used in combination with processor 2804 to provide graphical representations of aspects of the present disclosure. In addition to the display device, the computer system 2800 may include one or more other peripheral output devices, including but not limited to audio speakers, printers, and any combination thereof. Such peripheral output devices may be connected to bus 2812 via peripheral interface 2856. Embodiments of peripheral interfaces include, but are not limited to, serial ports, USB connections, FIREWIRE connections, parallel connections, and any combination thereof.

[0182] The above has been a detailed description of an illustrative embodiment of the present invention. Note that in the specification and the appended claims, connective language, such as used in the phrases "at least one of X, Y, and Z" and "one or more of X, Y, and Z", unless otherwise specifically stated or indicated, should be taken to mean that each item in the connective list may exist in any number excluding every other item in the list or in any number combined with any or all of the other items in the connective list, each of which may also exist in any number. Applying this general rule, the connective phrases in the above examples in which the connective list consists of X, Y, and Z should each cover: one or more of X; one or more of Y; one or more of Z; one or more of X and one or more of Y; one or more of Y and one or more of Z; one or more of X and one or more of Z; and one or more of X, one or more of Y, and one or more of Z.

[0183] Various modifications and additions can be made without departing from the spirit and scope of the present disclosure. The features of each of the various embodiments described above can be combined with the features of other described embodiments as appropriate to provide a variety of feature combinations in associated new embodiments. In addition, although many separated embodiments are described above, the content described herein is only an illustration of the application of the principles of the present disclosure. In addition, although the specific methods herein can be illustrated and / or described as being performed in a specific order, the order is highly variable within common sense to realize the aspects of the present disclosure. Accordingly, this description is intended to be only by way of example, and does not otherwise limit the scope of the present disclosure.

Claims

1. A method for manufacturing a negative electrode, the negative electrode comprising a current collector foil having a first side and a second side spaced apart from each other, a current collector foil located on the first side and having a thickness of t a and a first alkali metal layer located on the second side and having a thickness of t PEP The second alkali metal layer of receiving an alkali metal foil; receiving a porous carrier film collector foil laminate having a plurality of openings, each of the openings having a volume extending through the openings, the porous carrier film collector foil laminate comprising the collector foil and a first carrier film attached to the collector foil, wherein the first carrier film has a thickness t cf， is selected as the thickness t of the second alkali metal layer on the second side of the current collector foil. PEP Function of laminating the Alkali metal foil and the porous support film current collector foil laminate together at the first side of the porous current collector, wherein the laminating includes forming a portion of the Alkali metal foil extending through the opening so as to fill the volume of the opening and having the first Alkali metal layer having the thickness t a A plurality of extruded portions; removing the first carrier film from the current collector foil so that the extruded portion remains with the current collector foil; and The extruded portion is flattened to form a layer having a thickness t PEP The second alkali metal layer is formed and the negative electrode is formed.

2. The method of claim 1, wherein the thickness t a and the thickness t PEP Less than 20μm respectively.

3. The method of claim 1 wherein said openings in said porous support film current collector foil laminate define a percent open area greater than 40%. The method of claim 1 , wherein the opening has a maximum width greater than 0.5 mm.

5. The method of claim 1 wherein said porous support film current collector foil laminate has a minimum web width extending between adjacent ones of said openings, wherein said minimum web width is less than 1 mm.

6. The method of claim 1 wherein said openings in said porous support film current collector foil laminate define a percent open area greater than 80%.

7. The method of claim 1 wherein said porous support film current collector foil laminate has a minimum web width extending between adjacent ones of said openings, wherein said minimum web width is less than 0.25 mm.

8. The method of claim 1, wherein the alkali metal foil has a thickness t MF , and the first carrier film has a value greater than or equal to t MF / 2 thickness t FCF .

9. The method of claim 1 wherein the Alkali metal foil has a width greater than 55 mm.

10. The method of claim 9 wherein said laminating step comprises laminating a plurality of rows of said alkali metal foil in a closely spaced parallel arrangement across said porous support film current collector foil laminate so as to enable formation of a wide width negative electrode having a width in the range of 55 mm to 300 mm.

11. The method of claim 1, wherein the first carrier film has a thickness t in the range of 1 μm to 300 μm. FCF .

12. The method according to claim 1, wherein the thickness t of the first alkali metal layer is a is equal to the thickness t of the second alkali metal layer PEP .

13. The method of claim 1, wherein receiving the porous support film current collector foil laminate comprises receiving the porous support film current collector foil laminate from a first roll, and further comprising collecting the negative electrode on a second roll after the planarizing.

14. The method of claim 1, further comprising, prior to receiving the porous carrier film current collector foil laminate having a plurality of the openings: attaching a second carrier film to the first carrier film of the porous carrier film current collector foil laminate; cutting the porous carrier film current collector foil laminate without cutting the second carrier film to form chippings at the locations of the openings; as well as The second support film is removed from the porous support film current collector foil laminate to remove the burrs and form the openings in the porous support film current collector foil laminate. 15 . The method of claim 14 , wherein the first carrier film and the second carrier film have different thicknesses from each other.

16. The method of any one of claims 1 to 15, wherein the alkali metal foil comprises lithium metal.

17. A secondary battery comprising: Alkali metal negative electrode, positive electrode and separator; The alkali metal negative electrode is manufactured according to the method according to any one of claims 1 to 15. 18 . The secondary battery according to claim 17 , wherein the alkali metal anode is a lithium metal anode.

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