Vertically integrated pure lithium metal production and lithium battery production

Abstract

High-purity lithium metal electrodes were fabricated from aqueous lithium salt solutions using electrolysis through a lithium ion-selective membrane, achieving currents of approximately 10 mA / cm. 2 ~about 50mA / cm 2 A method is proposed in which the electrolysis is carried out at a constant current density of 0.1 V, where the constant current is applied for a time period of about 1 minute to about 60 minutes. The electrolysis is carried out under an overlying atmosphere, where the overlying atmosphere is substantially free of lithium reactive components. A method is further proposed for vertically integrating the electrolytic fabrication of high purity lithium metal electrodes into the production of lithium metal batteries, where the fabrication of lithium electrodes and lithium metal batteries is carried out in a single facility.

Description

[Technical Field]

[0001] The present invention relates to the production of high purity lithium for use in lithium metal batteries and the integration of lithium metal production with the production of Li batteries. The resulting batteries are produced in a fully charged state and have increased cycle life compared to conventional manufacturing methods. (CROSS-REFERENCE TO RELATED APPLICATIONS)

[0002] This patent application claims the benefit of U.S. patent application Ser. No. 17 / 006,073, filed Aug. 28, 2020, the disclosure of which is incorporated herein by reference. A related application, entitled "Lithium Metal Anode and Battery," filed Aug. 28, 2020, and having the same inventors and assignee as the present application, which assigned U.S. patent application Ser. No. 17 / 006,048, is also further incorporated by reference. [Background technology]

[0003] Lithium-ion batteries (LIBs) dominate the lithium battery market. LIBs contain lithium, which exists only in ionic form. Such batteries have good charge densities and can function effectively through multiple charge / discharge cycles. Lithium metal batteries (LMBs), in contrast, use non-ionic lithium metal in the negative electrode. During LMB discharge, lithium ions are released from this electrode as electrons flow through an external circuit. As LMBs recharge, lithium ions are reduced back to lithium metal as electrons flow back into the negative electrode. Because LMBs have inherently higher capacity than LIBs, they are the preferred technology for primary batteries. Furthermore, because LMBs can be fabricated in a fully charged state, they do not require the lengthy formation process required for LIBs, which can take 20–30 days. However, the tendency to form lithium metal dendrites, which can lead to poor cycle life, volume expansion, and violent combustion of LMBs, limits their practical use as rechargeable batteries.

[0004] The lithium anode in rechargeable lithium metal batteries (LMBs) is considered the "Holy Grail" of anode materials due to its remarkably high theoretical specific capacity of 3,860 mAh / g and low reaction voltage. Lithium metal is the lightest metal on the periodic table, which is particularly desirable for applications requiring a low volume-to-weight ratio, such as electric vehicles. The most promising LMBs are lithium-sulfur (Li-S), lithium-air (Li-O), and solid-state or semi-solid LMBs. While primary batteries fabricated using lithium metal foils have been widely commercialized, numerous barriers to the commercialization of rechargeable LMBs include low coulombic efficiency, poor cycle life, soft shorts, volume expansion, and the growth of Li dendrites during plating, which can lead to thermal runaway and other catastrophic failures. Significant efforts have been made to suppress dendrite formation, including by providing additives in the electrolyte, varying the salt concentration, creating an artificial passivation layer on the lithium metal (which allows handling of the lithium metal in dry air for short periods of time, but at the expense of higher impedance), and manipulating the electrode-electrolyte interface structure (which is extremely difficult to do when a foil is mechanically fused to a substrate to create the negative electrode, which is then mechanically fused to the solid-state electrolyte).

[0005] Other barriers include the quality and cost of available lithium metal raw materials, handling of lithium metal, and the mechanical challenges of fabricating lithium anodes. These barriers increase by several orders of magnitude when attempting to mechanically fabricate solid-state LMBs. Since 1976, researchers, including Nobel Prize winners, have attempted to solve all these problems, but to no avail. It is unfortunate that, as of 2020, despite all the efforts in this field, there remains a lack of commercially viable batteries for consumer applications.

[0006] Current commercial supplies of lithium metal are produced by molten salt electrolysis of lithium chloride. The lithium is poured into a mold and extruded into foils ranging in thickness from 100 μm to 750 μm. For environmental reasons, lithium metal foils are generally produced in China. Due to lithium's classification as a flammable and potentially explosive material, these foils must then be shipped to battery manufacturers in mineral oil. This process results in impure foils that appear dendritic in nature, with a non-uniform surface appearance that can vary by + / - 50 μm under scanning electron microscopy (SEM) imaging (U.S. Pat. No. 10,177,366, Figure 11A). The resulting impure product is sufficient for primary lithium batteries but is not usable in rechargeable LMBs.

[0007] Shipping and handling, as well as the required immersion in mineral oil, compromise the integrity of the lithium metal. Prior to use in a battery, the mineral oil must be removed, which further compromises the lithium. Some battery developers manually rub the lithium from under the top layer for use and distribute it on copper or other substrates like peanut butter. Some battery developers employ lithium metal foil and deposit it on the substrate, which is both expensive and energy intensive.

[0008] Impurities in this supply of lithium metal foil present an additional barrier to the commercialization of LMBs. As an alkali metal, lithium has one loosely held valence electron, making it inherently reactive. Notably, lithium is the only alkali metal that reacts with nitrogen in air to form the nitride Li3N. Due to undesirable side reactions, the introduction of impurities into lithium foil significantly limits the operation of working batteries. In particular, recent studies have found that such impurities can lead to the nucleation of subsurface dendritic structures (Harry et al., Nat. Mater. 13, 69-73 (2014)). The manufacturer of the lithium foil in this study (FMC Lithium) lists several elements other than lithium, the most abundant of which, at a concentration of 300 ppm by weight, is nitrogen, likely in the form of Li3N (US Pat. No. 4,781,756). Other common impurities include Na, Ca, K, Fe, Si, Cl, B, Ti, Mg, and C. This is not a comprehensive list, but the elements mentioned are the most common. Nitrogen, in any form, is undesirable, especially in rechargeable LMBs. Nitrogen forms voids and depressions in the lithium metal as the battery cycles, consuming lithium as a result of these reactions. The presence of impurities such as nitrogen leads to slow and uneven lithium deposition on the negative electrode during charging, affecting the overall current distribution within the battery and creating hot spots.

[0009] Non-uniformity of the lithium foil surface caused by nitrogen and other impurities is also very problematic because it interferes with uniform contact of the substrate with the electrode, leading to soft shorts and, again, non-uniform distribution of current, which in turn can lead to dendrites and other undesirable effects.

[0010] A method is needed to provide a pure lithium metal anode that overcomes the purity issues that traditionally limit the capacity and recycle life of LMBs. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] U.S. Patent No. 10,177,366 Summary of the Invention [Means for solving the problem]

[0012] While the common approach is to suppress all of the problems inherent in the existing supply of raw materials, an approach that has been unsuccessful for over 43 years, the inventors propose to simultaneously address the material and manufacturing issues by producing a highly improved lithium metal product (complete negative electrode) and vertically integrating lithium metal production into the battery manufacturing facility.

[0013] According to one embodiment of the present invention, a method for manufacturing a lithium electrode is described, the method comprising: (1) Providing an electrolytic cell, the electrolytic cell comprising: a first chamber containing a positive electrode and an aqueous lithium salt solution in contact with the positive electrode; a second chamber including a conductive substrate configured as a negative electrode, the conductive substrate being stationary within the chamber during lithium metal electrodeposition, a lithium ion selective membrane separating the first chamber from the second chamber, and a non-aqueous electrolyte disposed between the conductive substrate and the lithium ion selective membrane and in physical contact with both the conductive substrate and the lithium ion selective membrane; the electrolytic cell is configured to allow passage of lithium ions through the lithium ion selective membrane between the first chamber and the second chamber and to prevent passage of other chemical species between the first chamber and the second chamber; (2) covering the electrolytic cell with an overlying atmosphere, the overlying atmosphere being substantially free of lithium reactive components; (3) applying a variable voltage to maintain a constant current across the negative electrode and the positive electrode, thereby causing lithium ions to migrate from the first chamber to the second chamber, across the lithium ion selective membrane and the non-aqueous electrolyte, and electrodeposit a first layer of lithium onto the conductive substrate, thereby forming a lithium electrode, the first layer of lithium having an inner surface and an outer surface, the inner surface of the first layer of lithium being bonded to the conductive substrate; Including, The constant current is approximately 10mA / cm 2 ~about 50mA / cm 2 The constant current is applied for a period of time ranging from about 1 minute to about 60 minutes.

[0014] According to some embodiments, the blanket atmosphere contains 10 ppm or less of lithium reactive components on a molar basis. In some embodiments, the blanket atmosphere contains 10 ppm or less of nitrogen on a molar basis. In some embodiments, the blanket atmosphere contains 5 ppm or less of nitrogen on a molar basis.

[0015] According to some embodiments, the conductive substrate comprises a plate having a first side and a second side, and an inner surface of the first layer of lithium metal is bonded to the first side of the conductive substrate.

[0016] According to some embodiments, the aqueous lithium salt solution comprises a lithium salt selected from the group consisting of Li2SO4, Li2CO3, and combinations thereof. In a preferred embodiment, the aqueous lithium salt solution comprises Li2SO4.

[0017] According to some embodiments, the conductive substrate is selected from the group consisting of copper, aluminum, graphite-coated copper, and nickel.

[0018] According to some embodiments, the lithium ion selective membrane includes a polymer matrix and a plurality of ion-conducting particles disposed within the polymer matrix. In some embodiments, the lithium ion selective membrane comprises a glass frit having lithium ion-conducting particles disposed therein. According to some embodiments, the overlying atmosphere comprises argon with a purity greater than 99.998 weight percent. According to some embodiments, the lithium electrode has a specific capacity greater than about 3,800 mAh lithium per gram.

[0019] According to one embodiment of the present invention, a method for manufacturing a lithium electrode is described, the method comprising: (1) Providing a gas-impermeable container, the container comprising: an overlying atmosphere, wherein the overlying atmosphere is substantially free of lithium reactive components; An electrolytic cell, the electrolytic cell being completely surrounded by an overlying atmosphere, the electrolytic cell comprising: a conductive substrate stationary within the cell and configured as a negative electrode; A positive electrode; an aqueous lithium salt solution interposed between the conductive substrate and the positive electrode; a lithium ion selective membrane configured to function as a solid-state electrolyte, covering the conductive substrate and forming a barrier separating the aqueous lithium salt solution from the conductive substrate; an electrolytic cell configured to allow passage of lithium ions from a lithium salt solution through a lithium ion selective membrane onto a surface of the conductive substrate while preventing passage of other chemical species; and (2) applying a variable voltage to maintain a constant current across the negative electrode and the positive electrode, thereby causing lithium ions to migrate from the lithium salt solution across the lithium ion selective membrane and electroplate a layer of lithium onto the conductive substrate, thereby forming a lithium electrode, the layer of lithium having an inner surface and an outer surface, the inner surface bonded to the conductive substrate and the outer surface bonded to the lithium ion selective membrane; Including, The constant current is approximately 10mA / cm 2 ~about 50mA / cm 2 The constant current is applied for a period of time ranging from about 1 minute to about 60 minutes.

[0020] According to one embodiment of the present invention, a method of manufacturing a lithium metal battery is described, comprising: (1) preparing a lithium electrode according to the method of the present invention; (2) assembling a casing with contents including a lithium electrode configured as an anode and other components necessary to form a lithium metal battery; (3) sealing the casing to isolate the contents of the casing from reactants present in the air, thereby providing a lithium metal battery; Includes:

[0021] In preferred embodiments, the LIMB is fabricated in a single fabrication facility. In some embodiments, all steps of battery fabrication are performed under an overlying atmosphere that is substantially free of lithium reactive components.

[0022] In some embodiments, a lithium metal battery is fabricated using a lithium metal electrode having a layer of lithium metal bonded to a conductive substrate, the layer of lithium metal containing 5 ppm or less by mass of non-metallic elements.

[0023] According to one embodiment of the present invention, a method of manufacturing a lithium metal battery is described, comprising: (1) Providing an electrolytic cell, the electrolytic cell comprising: a conductive substrate stationary within the electrolytic cell, the conductive substrate comprising a plate having a first surface and a second surface; a first chamber containing a first positive electrode and a first aqueous lithium salt solution in contact with the first positive electrode; a second chamber including a first lithium ion selective membrane and a first non-aqueous electrolyte disposed between the first side of the conductive substrate and the first lithium ion selective membrane, the first lithium ion selective membrane separating the first chamber from the second chamber, and the first non-aqueous electrolyte in physical contact with both the first side of the conductive substrate and the lithium ion selective membrane; a third chamber including a second lithium ion selective membrane and a non-aqueous electrolyte disposed between the second side of the conductive substrate and the second lithium ion selective membrane, the non-aqueous electrolyte being in physical contact with both the second side of the conductive substrate and the second lithium ion selective membrane; a fourth chamber containing a second positive electrode and a second aqueous lithium salt solution in contact with the second positive electrode; a second lithium ion selective membrane separating the third chamber from the fourth chamber; an electrolytic cell configured to allow passage of lithium ions through a first lithium ion selective membrane between the first chamber and the second chamber and to prevent passage of other chemical species between the first chamber and the second chamber; the electrolytic cell is configured to allow passage of lithium ions through the second lithium ion selective membrane between the fourth chamber and the third chamber and to prevent passage of other chemical species between the fourth chamber and the third chamber; (2) completely covering the electrolytic cell with an overlying atmosphere, the overlying atmosphere being inert to chemical reaction with lithium; (3) applying a variable voltage across the conductive substrate and the second positive electrode to maintain a constant current across the conductive substrate and the first positive electrode, thereby causing lithium ions to migrate from the first chamber to the second chamber, across the first lithium ion selective membrane and the first non-aqueous electrolyte, and electroplate a first layer of lithium on the first side of the conductive substrate, and further causing lithium ions to migrate from the fourth chamber to the third chamber, across the second lithium ion selective membrane and the second non-aqueous electrolyte, and electroplate a second layer of lithium on the second side of the conductive substrate, thereby forming a lithium electrode, the lithium electrode comprising a conductive substrate, a first layer of lithium, and a second layer of lithium, the first layer of lithium having an inner surface and an outer surface, the inner surface bonded to the first side of the conductive substrate, and the second layer having an inner surface and an outer surface, the inner surface bonded to the second side of the conductive substrate; Including, The constant current is approximately 10mA / cm 2 ~about 50mA / cm 2 The constant current is applied for a period of time ranging from about 1 minute to about 60 minutes.

[0024] According to one embodiment of the present invention, a method of manufacturing a lithium metal battery is described, comprising: (1) Providing an electrolytic cell, the electrolytic cell comprising: a conductive substrate stationary within the cell, the conductive substrate comprising a plate having a first surface and a second surface, the first surface being covered with a first lithium ion selective membrane and the second surface being covered with a second lithium ion selective membrane, the first and second lithium ion selective membranes being configured to function as a solid-state electrolyte; a first chamber containing a first positive electrode and a first aqueous lithium salt solution in contact with the first positive electrode and the first lithium ion selective membrane; a second chamber containing a second positive electrode and a second aqueous lithium salt solution in contact with the first positive electrode and the second lithium ion selective membrane; the electrolytic cell is configured to allow passage of lithium ions through a first lithium ion selective membrane between the first chamber and the first side of the conductive substrate and to prevent passage of other chemical species between the first chamber and the first side of the conductive substrate; the electrolytic cell is configured to allow passage of lithium ions through a second lithium ion selective membrane between the second chamber and the second side of the conductive substrate and to prevent passage of other chemical species between the second chamber and the second side of the conductive substrate; (2) completely covering the electrolytic cell with an overlying atmosphere, the overlying atmosphere being inert to chemical reaction with lithium; (3) applying a variable voltage across the conductive substrate and the second positive electrode to maintain a constant current across the conductive substrate and the first positive electrode, thereby causing lithium ions to migrate from the first chamber across the first lithium ion selective membrane and electroplate a first layer of lithium onto the first side of the conductive substrate, and further causing lithium ions to migrate from the second chamber across the second lithium ion selective membrane and electroplate a second layer of lithium onto the second side of the conductive substrate, thereby forming an electrode, the lithium electrode comprising a conductive substrate, a first layer of lithium, and a second layer of lithium, the first layer of lithium having an inner surface and an outer surface, the inner surface of the first layer of lithium bonded to a first surface of the conductive substrate, the outer surface of the first layer of lithium bonded to a first lithium ion selective membrane, the second layer of lithium having an inner surface and an outer surface, the inner surface of the second layer of lithium bonded to a second surface of the conductive substrate, and the outer surface of the second layer of lithium bonded to a second lithium ion selective membrane; Including, The constant current is approximately 10mA / cm 2 ~about 50mA / cm 2 The constant current is applied for a period of time ranging from about 1 minute to about 60 minutes.

[0025] According to an embodiment of the present invention, a method of fabricating a lithium metal electrode is described, wherein the lithium ion selective membrane is immobile in an electrolytic cell, and as the first layer of lithium is formed, the first layer of lithium displaces non-aqueous electrolyte from a space between the conductive substrate and the lithium ion selective membrane, thereby bonding an inner surface of the first layer of lithium to the conductive substrate and bonding an outer surface of the first layer of lithium to the ion selective membrane, thereby forming a lithium metal electrode comprising the conductive substrate and the first layer of lithium metal, with the inner surface of the first layer of lithium bonded to the conductive substrate and the outer surface of the first layer of lithium bonded to the lithium ion selective membrane, and the lithium ion selective membrane is configured to function as a solid-state electrolyte when the lithium metal electrode is incorporated into a galvanic cell.

[0026] According to an embodiment of the present invention, a method of manufacturing a lithium metal battery is described, wherein first and second lithium ion selective membranes are immobile in an electrolytic cell; as a first layer of lithium is formed, the first layer of lithium displaces a first non-aqueous electrolyte from a space between a first surface of a conductive substrate and the first lithium ion selective membrane, thereby bonding an inner surface of the first layer of lithium to the first surface of the conductive substrate; bonding an outer surface of the first layer of lithium to the first lithium ion selective membrane; and as a second layer of lithium is formed, the second layer of lithium displaces a second non-aqueous electrolyte from a space between a second surface of the conductive substrate and the second lithium ion selective membrane, thereby bonding an inner surface of the first layer of lithium to the first lithium ion selective membrane. and bonding an inner surface of the second layer of lithium to the second surface and bonding an outer surface of the second layer of lithium to a second lithium ion selective membrane, thereby forming a lithium metal electrode comprising the conductive substrate and first and second layers of lithium metal, further with the inner surface of the first layer of lithium bonded to the first surface of the conductive substrate and the outer surface of the first layer of lithium bonded to the first lithium ion selective membrane, and the inner surface of the second layer of lithium bonded to the second surface of the conductive substrate, and the outer surface of the second layer of lithium bonded to the second lithium ion selective membrane, the first and second lithium ion selective membranes configured to function as a solid-state electrolyte when the lithium metal electrode is incorporated into a galvanic cell. The present invention provides, for example, the following. (Item 1) 1. A method for making a lithium electrode, said method comprising: (1) providing an electrolytic cell, the electrolytic cell comprising: a first chamber containing a positive electrode and an aqueous lithium salt solution in contact with the positive electrode; a second chamber including a conductive substrate configured as a negative electrode; Including, the conductive substrate is stationary within the chamber during lithium metal electrodeposition; a lithium ion selective membrane separates the first chamber from the second chamber; and a non-aqueous electrolyte is disposed between the conductive substrate and the lithium ion selective membrane and is in physical contact with both the conductive substrate and the lithium ion selective membrane; the electrolytic cell is configured to allow passage of lithium ions through the lithium ion selective membrane between the first and second chambers and to prevent passage of other chemical species between the first and second chambers; (2) covering the electrolytic cell with an overlying atmosphere, the overlying atmosphere being substantially free of lithium reactive components; (3) applying a variable voltage to maintain a constant current across the negative electrode and the positive electrode, thereby causing lithium ions to migrate from the first chamber to the second chamber, across the lithium ion selective membrane and the non-aqueous electrolyte, and electrodeposit a first layer of lithium onto the conductive substrate; Including, thereby forming the lithium electrode, the first layer of lithium having an inner surface and an outer surface, the inner surface of the first layer of lithium being bonded to the conductive substrate; The constant current is about 10 mA / cm 2 ~about 50mA / cm 2 wherein the constant current is applied for a time period of about 1 minute to about 60 minutes. (Item 2) Item 10. The method of claim 1, wherein the overlying atmosphere contains 10 ppm or less of lithium reactive components on a molar basis. (Item 3) 2. The method of claim 1, wherein the overlying atmosphere contains no more than 10 ppm nitrogen on a molar basis. (Item 4) 2. The method of claim 1, wherein the overlying atmosphere contains no more than 5 ppm nitrogen on a molar basis. (Item 5) Item 10. The method of claim 1, wherein the conductive substrate comprises a plate having a first side and a second side, and the inner surface of the first layer of lithium metal is bonded to the first side of the conductive substrate. (Item 6) The aqueous lithium salt solution comprises Li 2 SO 4 , Li 2 CO 3 and combinations thereof. (Item 7) The aqueous lithium salt solution comprises Li 2 SO 4 The method according to item 1, comprising: (Item 8) Item 10. The method of claim 1, wherein the conductive substrate is selected from the group consisting of copper, aluminum, graphite-coated copper, and nickel. (Item 9) Item 10. The method of claim 1, wherein the lithium ion selective membrane comprises a polymer matrix and a plurality of ion-conducting particles disposed within the polymer matrix. (Item 10) Item 10. The method of claim 1, wherein the lithium ion selective membrane comprises a glass frit and lithium ion conductive particles are disposed within the glass frit. (Item 11) Item 10. The method of claim 1, wherein the atmosphere comprises argon with a purity greater than 99.998 weight percent. (Item 12) Item 10. The method of claim 1, wherein the lithium electrode has a specific capacity of greater than about 3,800 mAh lithium per gram. (Item 13) 1. A method for making a lithium electrode, said method comprising: (1) Providing a gas-impermeable container, the container comprising: an overlying atmosphere, said overlying atmosphere being substantially free of lithium reactive components; Electrolytic cell and and The electrolytic cell is completely surrounded by the surrounding atmosphere, and the electrolytic cell comprises: a conductive substrate stationary within the electrolytic cell and configured as a negative electrode; A positive electrode; an aqueous lithium salt solution interposed between the conductive substrate and the positive electrode; a lithium ion selective membrane configured to function as a solid-state electrolyte; Including, the lithium ion selective membrane covers the conductive substrate and forms a barrier separating an aqueous lithium salt solution from the conductive substrate; the electrolytic cell is configured to allow the passage of lithium ions from the lithium salt solution through the lithium ion selective membrane to the surface of the conductive substrate while preventing the passage of other chemical species; (2) applying a variable voltage to maintain a constant current across the negative electrode and the positive electrode, thereby causing lithium ions to migrate from the lithium salt solution across the lithium ion selective membrane and electroplate a layer of lithium onto the conductive substrate, thereby forming the lithium electrode; Including, the layer of lithium has an inner surface and an outer surface, the inner surface being bonded to the conductive substrate and the outer surface being bonded to the lithium ion selective membrane; The constant current is about 10 mA / cm 2 ~about 50mA / cm 2 wherein the constant current is applied for a time period of about 1 minute to about 60 minutes. (Item 14) 1. A method of manufacturing a lithium metal battery, the method comprising: Producing a lithium electrode according to the method described in item 1; assembling a casing with contents including the lithium electrode configured as an anode and other components necessary to form the lithium metal battery; sealing said casing to isolate said contents of said casing from reactants present in air, thereby providing said lithium metal battery; A method comprising: (Item 15) 15. The method of manufacturing according to item 14, wherein the method is carried out in a single fabrication facility. (Item 16) 1. A method of manufacturing a lithium metal battery, the method comprising: Producing a lithium electrode according to the method described in item 13; assembling a casing with contents including the lithium ion selective electrode configured as an anode and other components necessary to form the lithium metal battery; sealing said casing to isolate said contents of said casing from reactants present in air, thereby providing said lithium metal battery; A method comprising: (Item 17) 17. The method of manufacturing according to item 16, wherein the method is carried out in a single fabrication facility. (Item 18) Item 18. The method of manufacturing according to item 17, wherein the method is carried out entirely under an atmosphere that is inert to chemical reactions with lithium. (Item 19) 1. A method of manufacturing a lithium metal battery, the method comprising: Fabricating a lithium metal electrode comprising a conductive substrate and a layer of lithium metal bonded to the conductive substrate, the layer of lithium metal containing 5 ppm or less by mass of non-metallic elements; assembling a casing with contents including the lithium metal electrode configured as an anode and other components necessary to form the lithium metal battery; sealing said casing to isolate said contents of said casing from reactants present in air, thereby providing said lithium metal battery; A method comprising: (Item 20) 20. The method of manufacturing according to item 19, wherein the method is carried out in a single fabrication facility. (Item 21) 21. The method of manufacturing according to item 20, wherein the method is carried out entirely under an atmosphere that is inert to chemical reactions with lithium. (Item 22) 1. A method for making a lithium electrode, said method comprising: (1) providing an electrolytic cell, the electrolytic cell comprising: a conductive substrate stationary within the electrolytic cell, the conductive substrate comprising a plate having a first surface and a second surface; a first chamber containing a first positive electrode and a first aqueous lithium salt solution in contact with the first positive electrode; a second chamber containing a first lithium ion selective membrane separating the first chamber from the second chamber, a first non-aqueous electrolyte disposed between the first surface of the conductive substrate and the first lithium ion selective membrane, the first non-aqueous electrolyte being in physical contact with both the first surface of the conductive substrate and the first lithium ion selective membrane; a third chamber containing a second lithium ion selective membrane and a non-aqueous electrolyte, the non-aqueous electrolyte being disposed between the second side of the conductive substrate and the second lithium ion selective membrane and in physical contact with both the second side of the conductive substrate and the second lithium ion selective membrane; a fourth chamber containing a second positive electrode and a second aqueous lithium salt solution in contact with the second positive electrode; Including, the second lithium ion selective membrane separating the third chamber from the fourth chamber; the electrolytic cell is configured to allow passage of lithium ions through the first lithium ion selective membrane between the first chamber and the second chamber and to prevent passage of other chemical species between the first chamber and the second chamber; the electrolytic cell is configured to allow passage of lithium ions through the second lithium ion selective membrane between the fourth chamber and the third chamber and to prevent passage of other chemical species between the fourth chamber and the third chamber; (2) completely covering the electrolytic cell with an overlying atmosphere, the overlying atmosphere being inert to chemical reaction with lithium; and (3) applying a variable voltage across the conductive substrate and the second positive electrode to maintain a constant current across the conductive substrate and the first positive electrode, thereby causing lithium ions to migrate from the first chamber to the second chamber, across the first lithium ion selective membrane and the first non-aqueous electrolyte, and electroplate a first layer of lithium on the first side of the conductive substrate; and further causing lithium ions to migrate from the fourth chamber to the third chamber, across the second lithium ion selective membrane and the second non-aqueous electrolyte, and electroplate a second layer of lithium on the second side of the conductive substrate, thereby forming the lithium electrode. Including, the lithium electrode comprises the conductive substrate, the first layer of lithium, and the second layer of lithium, the first layer of lithium having an inner surface and an outer surface, the inner surface being bonded to the first surface of the conductive substrate, and the second layer of lithium having an inner surface and an outer surface, the inner surface being bonded to the second surface of the conductive substrate; The constant current is about 10 mA / cm 2 ~about 50mA / cm 2 wherein the constant current is applied for a time period of about 1 minute to about 60 minutes. (Item 23) 1. A method for making a lithium electrode, said method comprising: (1) providing an electrolytic cell, the electrolytic cell comprising: a conductive substrate stationary within the cell, the conductive substrate comprising a plate having a first surface and a second surface, the first surface being covered with a first lithium ion selective membrane and the second surface being covered with a second lithium ion selective membrane, the first and second lithium ion selective membranes being configured to function as a solid-state electrolyte; a first chamber containing a first positive electrode and a first aqueous lithium salt solution in contact with the first positive electrode and the first lithium ion selective membrane; a second positive electrode; and a second chamber containing a second aqueous lithium salt solution in contact with the first positive electrode and the second lithium ion selective membrane. Including, the electrolytic cell is configured to allow passage of lithium ions through the first lithium ion selective membrane between the first chamber and the first side of the conductive substrate and to prevent passage of other chemical species between the first chamber and the first side of the conductive substrate; the electrolytic cell is configured to allow passage of lithium ions through the second lithium ion selective membrane between the second chamber and the second surface of the conductive substrate and to prevent passage of other chemical species between the second chamber and the second surface of the conductive substrate; (2) completely covering the electrolytic cell with an overlying atmosphere, the overlying atmosphere being inert to chemical reaction with lithium; and (3) applying a variable voltage across the conductive substrate and the second positive electrode to maintain a constant current across the conductive substrate and the first positive electrode, thereby causing lithium ions to migrate from the first chamber across the first lithium ion selective membrane and electroplate a first layer of lithium onto the first side of the conductive substrate, and further causing lithium ions to migrate from the second chamber across the second lithium ion selective membrane and electroplate a second layer of lithium onto the second side of the conductive substrate, thereby forming the lithium electrode; Including, the lithium electrode comprises the conductive substrate, the first layer of lithium, and the second layer of lithium, the first layer of lithium having an inner surface and an outer surface, the inner surface of the first layer of lithium bonded to the first surface of the conductive substrate, the outer surface of the first layer of lithium bonded to the first lithium ion selective membrane, the second layer of lithium having an inner surface and an outer surface, the inner surface of the second layer of lithium bonded to the second surface of the conductive substrate, and the outer surface of the second layer of lithium bonded to the second lithium ion selective membrane; The constant current is about 10 mA / cm 2 ~about 50mA / cm 2 wherein the constant current is applied for a time period of about 1 minute to about 60 minutes. (Item 24) Item 1, wherein the lithium ion selective membrane is stationary within the electrolytic cell, and as the first layer of lithium forms, the first layer of lithium displaces non-aqueous electrolyte from the space between the conductive substrate and the lithium ion selective membrane, thereby bonding the inner surface of the first layer of lithium to the conductive substrate and bonding the outer surface of the first layer of lithium to the ion selective membrane, thereby forming a lithium metal electrode comprising the conductive substrate and the first layer of lithium metal, the inner surface of the first layer of lithium bonded to the conductive substrate and the outer surface of the first layer of lithium bonded to the lithium ion selective membrane, and the lithium ion selective membrane is configured to function as a solid-state electrolyte when the lithium metal electrode is incorporated into a galvanic cell. (Item 25) The first and second lithium ion selective membranes are immobile within the electrolytic bath, and as the first layer of lithium forms, the first layer of lithium displaces the first non-aqueous electrolyte from the space between the first surface of the conductive substrate and the first lithium ion selective membrane, thereby bonding the inner surface of the first layer of lithium to the first surface of the conductive substrate and bonding the outer surface of the first layer of lithium to the first lithium ion selective membrane, and as the second layer of lithium forms, the second layer of lithium displaces the second non-aqueous electrolyte from the space between the second surface of the conductive substrate and the second lithium ion selective membrane, thereby bonding the inner surface of the second layer of lithium to the second surface of the conductive substrate. and bonding the outer surface of the second layer of lithium to the second lithium ion selective membrane, thereby forming a lithium metal electrode comprising the conductive substrate and the first and second layers of lithium metal, the inner surface of the first layer of lithium bonded to the first surface of the conductive substrate and the outer surface of the first layer of lithium bonded to the first lithium ion selective membrane, and the inner surface of the second layer of lithium bonded to the second surface of the conductive substrate and the outer surface of the second layer of lithium bonded to the second lithium ion selective membrane, the first and second lithium ion selective membranes configured to function as a solid-state electrolyte when the lithium metal electrode is incorporated into a galvanic cell. [Brief explanation of the drawings]

[0027] The foregoing features of the embodiments will be more readily understood by reference to the following detailed description, taken in conjunction with the accompanying drawings, in which:

[0028] [Figure 1] FIG. 1 shows steps in manufacturing a lithium metal battery according to one embodiment of the present invention.

[0029] [Figure 2] FIG. 2 shows a modified single-sided lithium metal electrode suitable for use as a working anode in a lithium metal battery according to one embodiment of the present invention.

[0030] [Figure 3] FIG. 3 shows an electrolytic cell for producing an improved single-sided lithium metal electrode suitable for use as a working anode in a lithium metal battery according to one embodiment of the present invention.

[0031] [Figure 4] FIG. 4 shows a modified double-sided lithium electrode suitable for use as a working anode in a lithium metal battery according to one embodiment of the present invention.

[0032] [Figure 5] FIG. 5 illustrates an electrolytic cell suitable for producing a double-sided electrode suitable for use as a working anode in a lithium metal battery according to one embodiment of the present invention.

[0033] [Figure 6] FIG. 6 shows a battery with a single-sided lithium metal electrode as the working anode, with a layer of high-purity lithium metal sandwiched between a conductive substrate and a lithium-ion selective membrane, the lithium-ion selective membrane configured to function as a solid-state electrolyte.

[0034] [Figure 7] FIG. 7 shows an electrolytic cell suitable for producing a single-sided lithium metal electrode, such as that shown in FIG. 6, prior to plating lithium metal on the conductive substrate of the battery, with the conductive substrate coated with a lithium ion selective membrane.

[0035] [Figure 8] FIG. 8 shows the electrolytic cell of FIG. 7 after plating lithium metal onto a conductive substrate according to an embodiment of the present invention, where the lithium metal is bonded to the conductive substrate on one side and to a solid-state electrolyte on the other side, and the electrode is suitable for use as a working anode in a lithium metal battery.

[0036] [Figure 9] FIG. 9 illustrates a battery according to one embodiment of the invention, which has a double-sided lithium electrode as the working anode, with lithium metal sandwiched between a conductive substrate and a lithium ion selective membrane, the lithium ion selective membrane configured to function as a solid-state electrolyte.

[0037] [Figure 10]FIG. 10 shows an electrolytic cell suitable for producing a double-sided lithium metal electrode of the type embodied in FIG. 9, where the conductive substrate is coated with a lithium ion selective membrane on both of its two faces prior to plating lithium metal on both sides of the battery's conductive substrate.

[0038] [Figure 11] FIG. 11 shows the electrolytic cell of FIG. 10 according to one embodiment of the present invention, where after plating of lithium metal onto each of the two sides of the conductive substrate, for each side, the lithium metal is bonded to the conductive substrate on one side and to the solid-state electrolyte on the other side, and the electrode is suitable for use as a working anode in a lithium metal battery.

[0039] [Figure 12] FIG. 12 shows a prior art lithium ion battery manufacturing facility.

[0040] [Figure 13] FIG. 13 illustrates a vertically integrated lithium metal battery manufacturing facility with manufacturing as embodied in the methods described herein.

[0041] [Figure 14] FIG. 14 shows a battery case for a battery with a single-sided lithium anode according to an embodiment of the present invention.

[0042] [Figure 15] FIG. 15 shows a battery case for a battery with a double-sided lithium anode according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0043] Definitions. As used in this description and the accompanying claims, the following terms shall have the meanings indicated, unless the context otherwise requires.

[0044] The "cathode" is the electrode where reduction occurs.

[0045] An "anode" is an electrode where oxidation occurs.

[0046] A "working anode" is the anode in a galvanic cell.

[0047] A "positive electrode" is the anode in an electrolytic cell or the cathode in a galvanic cell.

[0048] The "negative electrode" is the cathode in an electrolytic cell and the anode in a galvanic cell. Consequently, the lithium metal electrode is always the "negative electrode," even though it is the cathode in an electrolytic cell and the anode in a galvanic cell.

[0049] In the context of this application, "lithium metal electrode" and "lithium electrode" are synonymous and each refer to a negative electrode comprising lithium metal.

[0050] A "lithium metal battery" (or "LMB") is a battery that utilizes a negative electrode comprising pure lithium metal (i.e., a lithium metal electrode). The positive electrode for such a battery is typically an intercalation compound, such as TiS, which, during discharge, accepts electrons from the anode through an external circuit and incorporates Li into its lattice structure. + Insert.

[0051] A "lithium ion battery" is a rechargeable battery in which lithium ions shuttle between a negative electrode and an intercalation compound as the positive electrode.

[0052] The overlying atmosphere is "substantially free" of lithium reactive components when the atmosphere contains 10 ppm or less of lithium reactive components.

[0053] In the context of this disclosure, a "vertically integrated" lithium metal production facility is one in which lithium metal anodes are fabricated by electrodeposition at the facility and integrated into the battery manufacturing process.

[0054] FIG. 1 illustrates steps in the fabrication of a lithium metal battery (LMB) according to an embodiment of the present invention. An electrolytic cell, such as in the embodiments of FIGS. 2, 4, 6, 7, 9, and 10, is covered with an overlying atmosphere 2, where the overlying atmosphere is substantially free of lithium reactants, including nitrogen, oxygen, ozone, oxides of nitrogen, sulfur and phosphorus, carbon dioxide, halogens, hydrogen halides, and water. In some embodiments, the overlying atmosphere contains 10 ppm or less of lithium reactants on a molar basis. In some embodiments, the overlying atmosphere contains 5 ppm or less of lithium reactants on a molar basis. In preferred embodiments, the overlying atmosphere contains 10 ppm or less of nitrogen on a molar basis. In preferred embodiments, the overlying atmosphere contains 5 ppm or less of nitrogen on a molar basis. In preferred embodiments, the overlying atmosphere contains 1 ppm or less of nitrogen on a molar basis. In preferred embodiments, the overlying atmosphere is argon gas. In preferred embodiments, the argon gas has a purity greater than 99.998 weight percent. The electrolytic cell operates at or near room temperature and uses an aqueous lithium salt solution as the anolyte, which provides the lithium source for electrodeposition to form the negative electrode. In a preferred embodiment, the aqueous lithium salt solution contains lithium sulfate (LiSO) and / or lithium carbonate (LiCO). When LiSO solution is used as the feedstock, the only by-product is O gas, which is evolved at the anode and vented from the anolyte, without contacting the inert catholyte area. LiSO is a very cheap lithium source in the process chain, and thus, LiSO solution provides an economical source of lithium ions for the method according to the present invention. When LiCO is used as the feedstock, the minimal amount of carbon dioxide evolved can also be vented at the anode of the electrolytic cell. Typically, LiCO is more expensive than LiSO. However, it is not uncommon for battery manufacturers to receive lithium carbonate that does not meet quality control standards, and such lithium carbonate can easily be repurposed for lithium metal production.The aqueous lithium salt solution does not need to be highly concentrated because once the lithium ions are depleted by electrodeposition, the flow cell can allow the depleted lithium ions to be replaced.

[0055] The voltage across the electrolytic cell is adjusted to apply a constant current to the cell 4. The applied voltage causes lithium ions to flow from the anolyte to the catholyte 6 across the lithium ion selective membrane, which is configured to allow the passage of lithium ions but prevent the passage of other chemical species. At the cathode, the lithium ions are reduced to lithium metal, thereby plating onto a conductive substrate to form a lithium metal electrode 8. In some embodiments, the conductive substrate is selected from the group consisting of copper, aluminum, graphite-coated copper, and nickel. In a preferred embodiment, the conductive substrate is copper. The constant current is about 10 mA / cm. 2 ~about 50mA / cm 2 When applied within the range of 10 mA / cm, lithium ions cross the lithium ion selective membrane and electrodeposition onto the conductive substrate does not produce nanorods or dendrites. Rather, currents within this range produce extremely dense lithium metal deposits, allowing electrodeposition to proceed to completion within 1 to 60 minutes. In a preferred embodiment, the applied constant current is about 10 mA / cm. 2 ~about 50mA / cm 2 In a preferred embodiment, the constant current applied is about 25 mA / cm 2 ~about 50mA / cm 2 In a preferred embodiment, the constant current applied is about 40 mA / cm 2 ~about 50mA / cm 2 In a preferred embodiment, the density of the deposited lithium metal ranges from about 0.4 g / cm 3 ~0.543g / cm 3 In some preferred embodiments, the density of the deposited lithium metal ranges from 0.45 g / cm 3 ~0.543g / cm 3 Approximately 10mA / cm 2~about 50mA / cm 2 During the charge / discharge cycles of a battery fabricated using the lithium metal electrode of the present invention, a constant current of 1000 volts is higher than the operating current. Lithium metal electrodes formed at current densities higher than those used in operating batteries improve the charge-discharge recycling capacity of such batteries. Without being bound by theory, it is believed that lithium metal electrodes formed at current densities higher than those used in operating batteries will not form dendrites during cycling if no impurities are present anywhere in the battery. During the electrodeposition process, lithium continuously passes through the lithium ion-selective membrane and accumulates on the conductive substrate until the desired thickness is achieved (a 15 μm film can be produced in less than 5 minutes). Only lithium ions pass through the lithium ion-containing aqueous electrolyte, allowing for the use of inexpensive, impure feedstock solutions containing LiSO and / or LiCO. The lithium electrodeposited on the negative electrode is elementally pure and remains intact because it is never handled or exposed to air prior to entering the battery. Because electrodeposition occurs in an overlying atmosphere that is substantially free of lithium reactive components (including nitrogen), the formation of impurities (including, inter alia, Li3N) is avoided.

[0056] In some embodiments, the lithium electrodeposited on the negative electrode coats all sides of the negative electrode. In some embodiments, the copper is in the form of a mesh. In some embodiments, the copper is in the form of a foam. In some embodiments, the conductive substrate comprises a plate with two sides, and the lithium metal coats at least one side of the plate. In some embodiments, the lithium metal coats both of the two sides of the plate.

[0057] In some embodiments, the lithium ion-selective membrane is a hybrid organic-inorganic membrane comprising a polymer matrix and a plurality of ion-conducting particles disposed within the polymer matrix. In some such embodiments, an inorganic coating is deposited on the polymer matrix, the inorganic coating being a uniform layer 1 to 10,000 atoms thick. In some embodiments, the polymer can be a silica-based polyurethane, polyethylene oxide, polystyrene, or polyamide.

[0058] In some embodiments, the lithium ion selective membrane comprises a glass frit having lithium ion conducting particles disposed therein.

[0059] In some embodiments, the ion-conducting particles are LiFePO4, LiCoO2, NASICON electrolyte, lithium-lanthanum titanate (LLTO), garnet-type electrolytes, LISICON and Thio-LISICON electrolytes, Li7La3Zr3O 12 (LLZO), cubic phase (c-LLZO).

[0060] Finally, the lithium metal electrodes so formed are used in the fabrication of LMB 12. In preferred embodiments, all of the steps in the manufacturing method are performed in a single manufacturing facility. In some embodiments, the single manufacturing facility is a 10 km 2 In some embodiments, the manufacturing facility is within an area of ​​about 1 km 2 Because the lithium metal batteries of the present invention are fabricated in a fully charged state, the present invention reduces the footprint, cost, and time required for rechargeable batteries compared to conventional LIBs, which are first fabricated in an uncharged state and require time-consuming finishing steps to obtain a fully charged battery.

[0061] FIG. 2 provides a single-sided lithium metal electrode 15 according to one embodiment of the present invention. The lithium electrode 15 includes a conductive substrate 10 in the form of a plate having two sides. In a preferred embodiment, the conductive substrate is selected from the group consisting of copper, aluminum, graphite-coated copper, and nickel. A layer of lithium metal 60 is bonded to one of the two sides of the conductive substrate, the lithium metal containing 5 ppm or less by weight of non-metallic elements. In a preferred embodiment, the lithium metal contains 1 ppm or less by weight of non-metallic elements. In a preferred embodiment, the lithium metal contains 1 ppm or less by weight of nitrogen. In a preferred embodiment, the layer of lithium metal 60 has a thickness of about 1 micron to about 10 microns. The conductive substrate 10 and the layer of lithium metal 60 together constitute a single-sided lithium metal electrode 15 suitable for use as a fully charged working anode in an LMB. In a preferred embodiment, the lithium metal electrode 15 has a specific capacity of greater than about 3,800 mAh per gram of lithium metal. In a preferred embodiment, the lithium metal layer 60 has a density of about 0.4 g / cm 3 ~Approx. 0.534g / cm 3 In a preferred embodiment, the lithium metal layer 60 has a density of about 0.45 g / cm 3 ~Approx. 0.543g / cm 3 It has a density of

[0062] In a method for fabricating the single-sided lithium electrode 15 shown in FIG. 2, an electrolytic cell 5 is used as shown in FIG. 3. During the fabrication process, the electrolytic cell 5 of this embodiment is completely covered with an overlying atmosphere 24, which is substantially free of lithium reactants. In a preferred embodiment, the overlying atmosphere contains 10 ppm or less of lithium reactants on a molar basis. In a preferred embodiment, the overlying atmosphere contains 5 ppm or less of lithium reactants on a molar basis. In a preferred embodiment, the overlying atmosphere contains 10 ppm or less of nitrogen on a molar basis. In a preferred embodiment, the overlying atmosphere contains 5 ppm or less of nitrogen on a molar basis. In a preferred embodiment, the overlying atmosphere contains 1 ppm or less of nitrogen on a molar basis. In a preferred environment, the overlying atmosphere comprises argon with a purity greater than 99.998 weight percent. In the embodiment of FIG. 3, the overlying atmosphere 24 and the electrolytic cell 5 are enclosed within a gas-impermeable container 500. The electrolytic cell 5 includes a first chamber 26 and a second chamber 28. The first chamber 26 contains the positive electrode 20 and an aqueous lithium salt solution 40 in contact with the positive electrode 20. The second chamber 28 contains the lithium metal electrode 15, a lithium ion selective membrane 50, and a non-aqueous electrolyte 30. The lithium ion selective membrane 50 has a first side and a second side, physically separates the first chamber 26 from the second chamber 28, and contacts the aqueous lithium salt solution 40 on the first side. In the second chamber 28, the non-aqueous electrolyte 30 is disposed between the lithium metal electrode 15 and the second side of the lithium ion selective membrane 50 and physically contacts both the lithium metal electrode 15 and the second side of the lithium ion selective membrane 50. The lithium metal electrode 15, which includes a conductive substrate 10, is stationary during lithium metal electrodeposition in the second chamber and is electrodeposited with a layer of elemental lithium 60. The lithium ion selective membrane 50 allows lithium ions to pass between the first chamber 26 and the second chamber 28, but prevents the passage of other chemical species between the two chambers. In particular, the lithium ion selective membrane does not allow water to pass from the first chamber 26 to the second chamber 28.

[0063] In fabricating the single-sided lithium metal electrode 15 embodied in FIG. 2 , a variable voltage is applied across the positive electrode 20 of the electrolytic cell 5 and the conductive substrate 10 to maintain a constant current, causing lithium ions to migrate through the aqueous lithium salt solution 40, across the lithium ion selective membrane 50 from the first chamber 26 to the second chamber 28, into the non-aqueous electrolyte, and onto the surface of the stationary conductive substrate 10, where each lithium ion gains an electron, thereby causing a layer of elemental lithium 60 to be electrodeposited on the conductive substrate 10, thereby forming the single-sided lithium metal electrode 15.

[0064] In some embodiments, first chamber 26 of electrolytic cell 5 of FIG. 2 is a flow chamber with an inlet port 70 and an outlet port 80 that allows an aqueous lithium salt solution to enter first chamber 26 and provide a renewable source of lithium ions for electrodeposition.

[0065] In a preferred embodiment, the constant current is about 10 mA / cm 2 ~about 50mA / cm 2 In a preferred embodiment, the constant current applied is about 25 mA / cm 2 ~about 50mA / cm 2 In a preferred embodiment, the constant current applied is about 40 mA / cm 2 ~about 50mA / cm 2 In a preferred embodiment, the constant current is applied for a period of time ranging from about 1 minute to about 60 minutes.

[0066] In a preferred embodiment, the aqueous lithium salt solution 40 is selected from the group consisting of Li2SO4, Li2CO3, and combinations thereof. In a preferred embodiment, the aqueous lithium salt solution 40 includes Li2SO4. In a preferred embodiment, the lithium ion selective membrane 50 includes a polymer matrix and a plurality of ion-conducting particles disposed within the polymer matrix. In a preferred embodiment, the lithium ion selective membrane 50 includes a glass frit having lithium ion-conducting particles disposed therein.

[0067] FIG. 4 provides a double-sided lithium metal electrode according to one embodiment of the present invention. The double-sided lithium metal electrode 115 includes a conductive substrate 110 in the form of a plate having a first side and a second side. In a preferred embodiment, the conductive substrate 115 is selected from the group consisting of copper, aluminum, graphite-coated copper, and nickel. The first and second sides of the conductive substrate 115 are coated with lithium metal layers 160a and 160b, respectively, where the lithium metal contains 5 ppm or less by mass of non-metallic elements. In a preferred embodiment, the lithium metal contains 1 ppm or less by mass of non-metallic elements. In a preferred embodiment, the lithium metal layers 160a and 160b have thicknesses of about 1 micron to about 10 microns. The conductive substrate 110 and the lithium metal layers 160a and 160b together constitute the double-sided lithium metal electrode 115, which is suitable for use as a fully charged working anode in an LMB. In a preferred embodiment, the lithium metal electrode 115 has a specific capacity of greater than about 3,800 mAh per gram of lithium metal. In a preferred embodiment, each of the lithium metal layers 160a, 160b has a specific capacity of about 0.4 g / cm 3 ~Approx. 0.543g / cm 3 In a preferred embodiment, each of the lithium metal layers 160a, 160b has a density of about 0.45 g / cm 3 ~Approx. 0.543g / cm 3 It has a density of

[0068] In the method of fabricating the double-sided lithium electrode 115 shown in FIG. 4, an electrolytic cell 105 is used, as shown in FIG. 5. During the fabrication process, the electrolytic cell 105 of this embodiment is covered with an overlying atmosphere 24, which is inert to chemical reaction with lithium. In a preferred embodiment, the overlying atmosphere contains 10 ppm or less of a lithium reactant on a molar basis. In a preferred embodiment, the overlying atmosphere contains 5 ppm or less of a lithium reactant on a molar basis. In a preferred embodiment, the overlying atmosphere contains 10 ppm or less of nitrogen on a molar basis. In a preferred embodiment, the overlying atmosphere contains 5 ppm or less of nitrogen on a molar basis. In a preferred embodiment, the overlying atmosphere contains 1 ppm or less of nitrogen on a molar basis. In a preferred environment, the overlying atmosphere comprises argon with a purity greater than 99.998 weight percent. In the embodiment of FIG. 5, the overlying atmosphere 24 and the electrolytic cell 105 are enclosed within a gas-impermeable container 500. The electrolytic cell 105 includes a first chamber 126a, a second chamber 128a, a third chamber 126b, and a fourth chamber 128b. The first chamber 126a contains a positive electrode 120a and an aqueous lithium salt solution 140a in contact with the positive electrode 120a, and the third chamber 126b contains a positive electrode 120b and an aqueous lithium salt solution 140b in contact with the positive electrode 120b. The second chamber 128a and the fourth chamber 128b share a double-sided lithium metal electrode 115, which connects the two chambers. The double-sided lithium metal electrode 115 includes a central conductive substrate 110 having a first side and a second side, which are electrodeposited with lithium metal layers 160a and 160b, respectively. The lithium metal layer 160a extends into the second chamber 128a, and the lithium metal layer 160b extends into the fourth chamber. The second chamber 128a includes a lithium ion-selective membrane 150a and a non-aqueous electrolyte 130a. The lithium ion-selective membrane 150a has a first side and a second side, physically separates the first chamber 126a from the second chamber 128a, and contacts an aqueous lithium salt solution 140a on the first side.In the second chamber 128a, a non-aqueous electrolyte 130a is disposed between the lithium metal layer 160a and the second side of the lithium ion selective membrane 150a. The fourth chamber includes a lithium ion selective membrane 150b and a non-aqueous electrolyte 130b. The lithium ion selective membrane 150b has a first side and a second side, physically separates the third chamber 126b from the fourth chamber 128b, and contacts the aqueous lithium salt solution 140b on the first side. In the fourth chamber 128b, the non-aqueous electrolyte 130b is disposed between the lithium metal layer 160b and the second side of the lithium ion selective membrane 150b. The lithium ion selective membranes 150a, 150b allow lithium ions to pass between the first chamber 126a and the second chamber 128a and between the third chamber 126b and the fourth chamber 128b, respectively, but prevent the passage of other chemical species between the first chamber 126a and the second chamber 128a and between the third chamber 126b and the fourth chamber 128b, respectively.

[0069] When using the electrolytic cell 105 to fabricate the double-sided lithium metal electrode 115 embodied in FIG. 4 , a variable voltage is applied across the positive electrodes 120 a, 120 b and the conductive substrate 110 of the electrolytic cell 105 to maintain a constant current, causing lithium ions to migrate through the aqueous lithium salt solutions 140 a, 140 b, respectively, across from the first and third chambers 126 a, 126 b to the second and fourth chambers 128 a, 128 b, respectively, through the respective lithium ion selective membranes 150 a, 150 b, into the non-aqueous electrolytes 130 a, 130 b, respectively, and to the first and second sides of the conductive substrate 110 where each lithium ion gains an electron, thereby causing layers of elemental lithium 160 a, 160 b to be electrodeposited on the first and second sides, respectively, of the conductive substrate 110, thereby forming the double-sided lithium metal electrode 115. During electrodeposition of the lithium metal layers 160a, 160b onto the first and second sides of the conductive substrate 110, the conductive substrate 110 remains stationary.

[0070] In some embodiments, the first and third chambers 126a, 126b of the electrolytic cell 105 of FIG. 4 are flow chambers, and inlet ports 170a, 170b and outlet ports 180a, 180b allow aqueous lithium salt solutions 140a, 140b to enter the first chamber 126a and the third chamber 126b and provide a renewable supply of lithium ions for electrodeposition.

[0071] In a preferred embodiment, the constant current is about 10 mA / cm 2 ~about 50mA / cm 2 In a preferred embodiment, the constant current applied is about 25 mA / cm 2 ~about 50mA / cm 2 In a preferred embodiment, the constant current applied is about 40 mA / cm 2 ~about 50mA / cm 2 In a preferred embodiment, the constant current is applied for a period of time ranging from about 1 minute to about 60 minutes.

[0072] In a preferred embodiment, the aqueous lithium salt solutions 140a, 140b are selected from the group consisting of Li2SO4, Li2CO3, and combinations thereof. In a preferred embodiment, the aqueous lithium salt solutions 140a, 140b include Li2SO4. In a preferred embodiment, the lithium ion selective membranes 150a, 150b include a polymer matrix and a plurality of ion-conducting particles disposed within the polymer matrix. In a preferred embodiment, the lithium ion selective membranes 150a, 150b include a glass frit having lithium ion-conducting particles disposed therein.

[0073] FIG. 6 provides a galvanic cell 225 fabricated with a single-sided lithium metal electrode 215 configured to function as an anode. The lithium metal electrode 215 includes a conductive substrate 210 bonded to a layer 260 of lithium metal, the lithium metal containing 5 ppm or less by weight of non-metallic elements. In a preferred embodiment, the lithium metal contains 1 ppm or less by weight of non-metallic elements. In a preferred embodiment, the lithium metal contains 1 ppm or less by weight of nitrogen. The conductive substrate 210 and the layer 260 of lithium metal together comprise the single-sided lithium metal electrode 215 of the galvanic cell 225. In a preferred embodiment, the lithium metal electrode 215 has a specific capacity of greater than about 3,800 mAh per gram of lithium metal. In a preferred embodiment, the layer 260 of lithium metal has a specific capacity of about 0.4 g / cm. 3 ~Approx. 0.534g / cm 3 In a preferred embodiment, the lithium metal layer 260 has a density of about 0.45 g / cm 3 ~Approx. 0.543g / cm 3In a preferred embodiment, the conductive substrate is selected from the group consisting of copper, aluminum, graphite-coated copper, and nickel. A lithium metal layer 260 has a first side and a second side and is bonded to the conductive substrate 210 on the first side and to the lithium ion selective membrane 250 on the second side. The lithium ion selective membrane 250 is configured to function as a solid-state electrolyte. The lithium ion selective membrane 250 separates the lithium metal layer 260 from the catholyte 290. In a preferred embodiment, the catholyte 290 includes an ionic liquid-forming salt. In a preferred embodiment, the catholyte 290 comprises an ionic liquid. The catholyte 290 then separates the lithium ion selective membrane 250 from the cathode / catholyte interface 295, which covers a side of the cathode 235 and separates the cathode 235 from the catholyte 290. The anode 245 electrical contact allows electrons to flow from the electrode 215 to the corresponding electrical contact, the cathode 255, and then onto the cathode 235. In this configuration, the lithium ion selective membrane 250 is configured to function as a solid-state electrolyte. During battery discharge, the layer of pure lithium metal is oxidized to lithium ions, releasing electrons that flow from the single-sided electrode 215 to the cathode 235 through the electrical contacts 245, 255, and lithium ions that flow through the lithium ion selective membrane 250 into the catholyte 290 and into the cathode 235, where the electrons are taken up. In various embodiments, the catholyte 290 can comprise a salt containing organic cations and inorganic ions, capable of forming an ionic liquid. In embodiments, the catholyte 290 comprises an ionic liquid. In embodiments, the catholyte 290 comprises a lithium salt of an organic anion capable of forming an ionic liquid, the organic anion being trifluoromethanesulfonyl-imide (TFSI), N-butyl-N-methylpyrrolidinium bromide bis(trifluoromethanesulfonyl)imide (Pyr 14TFSI), trifluoromethanesulfonyl-imide, bis(trifluoromethanesulfonyl)imide (LiTFSI), and 1-ethyl-3-methylimidazolium-bis(trifluoromethylsulfonyl)imide (EMI-TFSI). In some embodiments, catholyte 290 comprises an ionic liquid-forming salt dissolved in 1,3-dioxolane (DOL), 1,2-dimethoxyethane (DME), or tetraethylene glycol dimethyl ether (TEGDME). In certain embodiments, the catholyte comprises concentrated (4.0-5.0 M) lithium bis(fluorosulfonyl)imide (LiFSI) in 1:1 DOL / DME.

[0074] Without being bound by theory, it is believed that elementally pure lithium metal chemically bonded to a substrate that is then chemically bonded to a lithium ion selective membrane configured to function as a solid-state electrolyte will eliminate impedance variations at the electrode / solid electrolyte separator interface, thereby minimizing dendrite formation.

[0075] In a method for fabricating by electrodeposition a single-sided lithium electrode 215 for the galvanic cell 225 of FIG. 6, an electrolytic cell 205 is used. FIG. 7 shows the electrolytic cell 205 prior to electrodeposition, and FIG. 8 shows the electrolytic cell following electrodeposition. According to the method, the electrolytic cell 205 is completely covered with an overlying atmosphere 24, which is inert to chemical reaction with lithium. In a preferred embodiment, the overlying atmosphere contains 10 ppm or less of a lithium reactant on a molar basis. In a preferred embodiment, the overlying atmosphere contains 5 ppm or less of a lithium reactant on a molar basis. In a preferred embodiment, the overlying atmosphere contains 10 ppm or less of nitrogen on a molar basis. In a preferred embodiment, the overlying atmosphere contains 5 ppm or less of nitrogen on a molar basis. In a preferred embodiment, the overlying atmosphere contains 1 ppm or less of nitrogen on a molar basis. In a preferred embodiment, the overlying atmosphere comprises argon with a purity greater than 99.998 weight percent. 7 and 8, the overlying atmosphere 24 and the electrolytic cell 5 are enclosed within a gas-impermeable container 500. During the process of electrodeposition, the electrolytic cell 205 is confined to the overlying atmosphere 24.

[0076] The electrolytic cell 205 includes a conductive substrate 210 configured as a negative electrode, an ion-selective membrane 250, an aqueous lithium salt solution 240, and a positive electrode 220. The aqueous lithium salt solution 240 is interposed between the conductive substrate 210 and the positive electrode 220. Prior to electrodeposition, the lithium ion-selective membrane 250 covers the conductive substrate 210 and forms a barrier separating the lithium salt solution 240 and the conductive substrate 210, as shown in FIG. 7. Prior to electrodeposition, the conductive substrate 210 is physically coated with the lithium ion-selective membrane 250 configured to function as a solid-state electrolyte, as shown in FIG. 7. After electrodeposition, a layer of lithium metal 260 is electrodeposited between the conductive substrate 210 and the lithium ion-selective membrane 250 and bonds to both the conductive substrate 210 and the lithium ion-selective membrane 250, as shown in FIG. 8. During the electrodeposition process, lithium ion selective membrane 250 separates conductive substrate 210 and electrodeposited lithium metal layer 260 from lithium salt solution 240. Lithium ion selective membrane 250 is configured to function as a solid-state electrolyte, allowing the passage of lithium ions from aqueous salt solution 240 to be electrodeposited onto the surface of conductive substrate 210, but preventing the passage of other chemical species.

[0077] In fabricating a single-sided lithium metal electrode 215 for the galvanic cell embodied in FIG. 6 , a variable voltage is applied across the positive electrode 220 and the conductive substrate 210 of the electrolytic cell 205 to maintain a constant current, causing lithium ions to migrate through the aqueous lithium salt solution 240, through the lithium ion selective membrane 250, and to the surface of the conductive substrate 210 where each lithium ion gains an electron, thereby causing a layer of elemental lithium 260 to be electrodeposited on the conductive substrate 210, thus bonding to the conductive substrate on a first side of the layer of elemental lithium 260 and to the lithium ion selective membrane 250 on a second side of the layer of elemental lithium 260. In this manner, as shown in FIGS. 7 and 8 , a single-sided lithium metal electrode 215 is fabricated such that a sandwich of the lithium metal layer 260 is formed between the conductive substrate 210 and the lithium ion selective membrane 250. During the electrodeposition process, the conductive substrate 210 is stationary in the electrolytic cell.

[0078] In some embodiments, the electrolytic cell 205 of FIG. 7 is a flow chamber, and an inlet port 270 and an outlet port 280 allow an aqueous lithium salt solution 240 to enter the electrolytic cell 205 and provide a renewable supply of lithium ions for electrodeposition.

[0079] In a preferred embodiment, the constant current is about 10 mA / cm 2 ~about 50mA / cm 2 In a preferred embodiment, the constant current applied is about 25 mA / cm 2 ~about 50mA / cm 2 In a preferred embodiment, the constant current applied is about 40 mA / cm 2 ~about 50mA / cm 2 In a preferred embodiment, the constant current is applied for a period of time ranging from about 1 minute to about 60 minutes.

[0080] In a preferred embodiment, the aqueous lithium salt solution 240 is selected from the group consisting of Li2SO4, Li2CO3, and combinations thereof. In a preferred embodiment, the aqueous lithium salt solution 240 includes Li2SO4. In a preferred embodiment, the lithium ion selective membrane 250 includes a polymer matrix and a plurality of ion-conducting particles disposed within the polymer matrix. In a preferred embodiment, the lithium ion selective membrane 250 includes a glass frit having lithium ion-conducting particles disposed therein.

[0081] In an alternative method for fabricating by electrodeposition the single-sided lithium electrode 215 of the galvanic cell 225 of Figure 6, the electrolytic cell 5 of Figure 3 is used. According to this method, both the lithium ion selective membrane 50 and the conductive substrate 10 remain stationary in the electrolytic cell. A variable voltage is applied across the positive electrode 20 of the electrolytic cell 5 and the conductive substrate 10 to maintain a constant current, thereby causing lithium ions to migrate through the aqueous lithium salt solution 40, across the lithium ion selective membrane 50 from the first chamber 26 to the second chamber 28, into the non-aqueous electrolyte, and to the surface of the conductive substrate 10 where each lithium ion gains an electron, thereby causing a layer of elemental lithium 60 to be electrodeposited on the conductive substrate 10. As the layer of elemental lithium 60 grows, it displaces non-aqueous electrolyte 30 from second chamber 28 and eventually contacts and bonds to lithium ion selective membrane 50, thereby forming single-sided lithium metal electrode 215 of FIG. 6 comprising conductive substrate 10 and layer of lithium 60 bonded on one side to conductive substrate 10 and on the other side to lithium ion selective membrane 50 configured to function as a solid-state electrolyte.

[0082] FIG. 9 provides a galvanic cell 325 fabricated using a double-sided lithium metal electrode 315 configured to function as an anode. The double-sided lithium metal electrode 315 includes a conductive substrate 310 in the form of a plate having a first and second surface, which are bonded to first and second lithium metal sheets 360a and 360b, respectively. The lithium metal contains 5 ppm or less by weight of non-metallic elements. In a preferred embodiment, the lithium metal contains 1 ppm or less by weight of non-metallic elements. In a preferred embodiment, the lithium metal contains 1 ppm or less by weight of nitrogen. The conductive substrate 310 and each of the first and second lithium metal layers 360a and 360b together constitute the double-sided lithium metal electrode 315 of the galvanic cell 325. In a preferred embodiment, the lithium metal electrode 315 has a specific capacity of greater than about 3,800 mAh per gram of lithium metal. In a preferred embodiment, each of the first and second layers 360a, 360b of lithium metal has a density of about 0.4 g / cm 3 ~Approx. 0.534g / cm 3 In a preferred embodiment, each of the lithium metal layers 360a, 360b has a density of about 0.45 g / cm 3 ~Approx. 0.543g / cm 3In a preferred embodiment, the conductive substrate is selected from the group consisting of copper, aluminum, graphite-coated copper, and nickel. Each lithium metal layer 360a, 360b has a first side and a second side, and is bonded to the conductive substrate 310 on the first side and to a lithium ion selective membrane 350a, 350b on the second side, respectively. The lithium ion selective membranes 350a, 350b are configured to function as solid-state electrolytes. The lithium ion selective membrane 350a separates the lithium metal layer 360a from the catholyte 390a. In a preferred embodiment, the catholyte 390a includes an ionic liquid-forming salt. In a preferred embodiment, the catholyte 390a comprises an ionic liquid. Catholyte 390a then separates lithium ion selective membrane 350a from cathode / catholyte interface 395a, which coats the surface of cathode 335a and separates cathode 335a from ionic liquid 390a. Lithium ion selective membrane 350b separates lithium metal layer 360b from catholyte 390b. In a preferred embodiment, catholyte 390b includes an ionic liquid-forming salt. In a preferred embodiment, catholyte 390b comprises an ionic liquid. Catholyte 390b then separates lithium ion selective membrane 350b from cathode / catholyte interface 395b, which coats the surface of cathode 335b and separates cathode 335b from ionic liquid 390b.

[0083] The electrical contacts of the anode 345 allow electrons to flow from the electrode 315 to the corresponding electrical contacts of the two cathodes 355a, 355b, respectively, and then to the cathodes 335a, 335b. During battery discharge, the layers of pure lithium metal 360a, 360b are oxidized to lithium ions, releasing electrons and lithium ions that flow from the double-sided electrode 315 through electrical contact 345, through electrical contacts 355a, 355b, to the cathodes 335a, 335b. The lithium ions flow through the lithium ion selective membranes 350a, 350b, into the ionic liquids 390a, 390b, and into the cathodes 335a, 335b, where they are inserted into the cathodes 335a, 335b, where the electrons are captured. In various embodiments, the catholyte may comprise a salt comprising an organic cation and an inorganic ion capable of forming an ionic liquid. In various embodiments, the catholyte 390a, 390b may comprise a salt comprising an organic cation and an inorganic ion capable of forming an ionic liquid. In embodiments, the catholyte 390a, 390b comprises an ionic liquid. In embodiments, the catholyte 390a, 390b comprises a lithium salt of an organic anion capable of forming an ionic liquid, the organic anion being trifluoromethanesulfonyl-imide (TFSI), N-butyl-N-methylpyrrolidinium bromide bis(trifluoromethanesulfonyl)imide (Pyr). 14 TFSI), trifluoromethanesulfonyl-imide, bis(trifluoromethanesulfonyl)imide (LiTFSI), and 1-ethyl-3-methylimidazolium-bis(trifluoromethylsulfonyl)imide (EMI-TFSI). In some embodiments, catholyte 390a, 390b comprises an ionic liquid-forming salt dissolved in 1,3-dioxolane (DOL), 1,2-dimethoxyethane (DME), or tetraethylene glycol dimethyl ether (TEGDME). In certain embodiments, catholyte 390a, 390b comprises concentrated (4.0-5.0 M) lithium bis(fluorosulfonyl)imide (LiFSI) in 1:1 DOL / DME.

[0084] Without being bound by theory, it is believed that elementally pure lithium metal chemically bonded to a substrate that is then chemically bonded to a lithium ion selective membrane configured to function as a solid-state electrolyte will eliminate impedance variations at the electrode / solid electrolyte separator interface, thereby minimizing dendrite formation.

[0085] In a method for fabricating by electrodeposition the double-sided lithium electrode 315 of the galvanic cell 325 of FIG. 9, an electrolytic cell 305 is used. FIG. 10 shows the electrolytic cell 305 prior to electrodeposition, and FIG. 11 shows the electrolytic cell following electrodeposition. According to the method, the electrolytic cell 305 is completely covered with an overlying atmosphere 24, which is inert to chemical reaction with lithium. In a preferred embodiment, the overlying atmosphere contains 10 ppm or less of a lithium reactant on a molar basis. In a preferred embodiment, the overlying atmosphere contains 5 ppm or less of a lithium reactant on a molar basis. In a preferred embodiment, the overlying atmosphere contains 10 ppm or less of nitrogen on a molar basis. In a preferred embodiment, the overlying atmosphere contains 5 ppm or less of nitrogen on a molar basis. In a preferred embodiment, the overlying atmosphere contains 1 ppm or less of nitrogen on a molar basis. In a preferred embodiment, the overlying atmosphere comprises argon with a purity greater than 99.998 weight percent. 11 and 12, the overlying atmosphere 24 and the electrolytic cell 5 are enclosed within a gas-impermeable container 500. During the process of electrodeposition, the electrolytic cell 305 is confined to the overlying atmosphere 24.

[0086] Electrolytic cell 305 includes first chamber 326a and second chamber 326b, where the first chamber has a proximal end and a distal end, and the second chamber has a proximal end and a distal end. Conductive substrate 310 is continuous with first chamber 326a and separates it from second chamber 326b, with conductive substrate 310 having a first side facing first chamber 326a and a second side facing second chamber 326b. Prior to electrodeposition, as embodied in FIG. 10 , the first and second sides of conductive substrate 310 are coated with a first lithium ion-selective membrane 350a configured to function as a solid-state electrolyte extending into the proximal end of first chamber 326a and a second lithium ion-selective membrane 350b configured to function as a solid-state electrolyte extending into the proximal end of second chamber 326b, respectively. At its distal end, first chamber 326a and second chamber 326b contain positive electrodes 320a and 320b, respectively. Positive electrode 320a and first lithium ion selective membrane 350a are separated by aqueous salt solution 340a, which is in physical contact with both positive electrode 320a and lithium ion selective membrane 350a. In a similar manner, positive electrode 320b and first lithium ion selective membrane 350b are separated by aqueous salt solution 340b, which is in physical contact with both positive electrode 320b and lithium ion selective membrane 350b.

[0087] After electrodeposition, as shown in FIG. 11, lithium metal layers 320a, 320b are electrodeposited between the conductive substrate 310 and the lithium ion selective membranes 350a, 350b, respectively, and the lithium metal layers 320a, 320b are bonded to the conductive substrate 310 and the lithium ion selective membranes 350a, 350b, respectively.

[0088] During the process of electrodeposition, lithium ion selective membranes 350a, 350b separate the conductive substrate 310 and electrodeposited lithium metal layers 360a, 360b from the lithium salt solutions 340a, 340b, respectively.

[0089] The lithium ion selective membranes 350a, 350b are configured to function as solid-state electrolytes, allowing lithium ions to pass between the aqueous lithium salt solutions 340a, 340b and the conductive substrate 310, while preventing the passage of other chemical species.

[0090] In fabricating a double-sided lithium metal electrode 315 for a galvanic cell as embodied in FIG. 9 , a variable voltage is applied across positive electrodes 320 a, 320 b of electrolytic cell 305 and conductive substrate 310 to maintain a constant current, causing lithium ions to migrate through aqueous lithium salt solutions 340 a, 340 b, respectively, through lithium ion selective membranes 350 a, 350 b, respectively, to the surface of conductive substrate 310 where each lithium ion gains an electron, thereby electrodepositing layers of elemental lithium 360 a, 360 b, respectively, on the first and second sides of conductive substrate 310, where the layers of elemental lithium 360 a, 360 b are thus bonded to conductive substrate 310 and lithium ion selective membranes 350 a, 350 b, respectively. 10 and 11, a double-sided lithium metal electrode 315 is fabricated as a sandwich with a central conductive substrate 310 bounded on both sides by layers 360, 360b of elemental lithium, which in turn are bounded by layers 350a, 350b of lithium ion selective membrane. During the electrodeposition process, the conductive substrate 310 is stationary in the electrolytic cell.

[0091] In some embodiments, the first and second chambers 326a, 326b of the electrolytic cell 305 of Figures 10 and 11 are flow chambers, and inlet ports 370a, 370b and outlet ports 380a, 380b allow aqueous lithium salt solutions 340a, 340b to enter the first chamber 326a and second chamber 326b and provide a renewable supply of lithium ions for electrodeposition.

[0092] In a preferred embodiment, the constant current is about 10 mA / cm 2 ~about 50mA / cm 2In a preferred embodiment, the constant current applied is about 25 mA / cm 2 ~about 50mA / cm 2 In a preferred embodiment, the constant current applied is about 40 mA / cm 2 ~about 50mA / cm 2 In a preferred embodiment, the constant current is applied for a period of time ranging from about 1 minute to about 60 minutes.

[0093] In a preferred embodiment, the aqueous lithium salt solutions 340a, 340b are selected from the group consisting of Li2SO4, Li2CO3, and combinations thereof. In a preferred embodiment, the aqueous lithium salt solutions 340a, 340b include Li2SO4. In a preferred embodiment, the lithium ion selective membranes 350a, 350b comprise a polymer matrix and a plurality of ion-conducting particles disposed within the polymer matrix. In a preferred embodiment, the lithium ion selective membranes 350a, 350b include a glass frit having lithium ion-conducting particles disposed therein.

[0094] In an alternative method for fabricating by electrodeposition the double-sided lithium electrode 315 of the galvanic cell 325 of Figure 9, the electrolytic cell 105 of Figure 5 is used. According to the method, each of the lithium ion selective membranes 150a, 150b and the conductive substrate 110 remains stationary in the electrolytic cell. A variable voltage is applied across the positive electrodes 120a, 120b and the conductive substrate 110 of the electrolytic cell 105 to maintain a constant current, causing lithium ions to migrate through the aqueous lithium salt solutions 140a, 140b, respectively, across from the first and fourth chambers 126a, 126b to the second and third chambers 128a, 128b, through the lithium ion selective membranes 150a, 150b, into the non-aqueous electrolytes 130a, 130b, and to the first and second faces of the conductive substrate 110 where each lithium ion gains an electron, thereby causing a layer of elemental lithium 160a, 160b to be electrodeposited on the conductive substrate 110. As the layers of elemental lithium 160a, 160b grow, they displace the non-aqueous electrolyte 130a, 130b from the second and third chambers 128a, 128b, respectively, and eventually contact and bond to the lithium ion selective membranes 150a, 150b, thereby forming the double-sided lithium metal electrode 315 of FIG. 9 comprising the conductive substrate 110 and the layers of lithium 160a, 160b, respectively, connected on the first and second sides of the conductive substrate 110 and bonded to the lithium ion selective membranes 150a, 150b, which are configured to function as a solid-state electrolyte.

[0095] In a preferred embodiment, the lithium metal electrodes described herein can be integrated into batteries, including but not limited to the batteries embodied in FIGS.

[0096] The methods described above are well suited for vertically integrated battery production, thereby enabling a locally controlled supply chain for LMB production in any region where lithium is mined (e.g., the United States). The development of such a localized regional supply chain would significantly reduce costs and provide essentially cobalt-free LMB.

[0097] A typical fabrication facility for prior art lithium-ion batteries is shown in FIG. 12. The manufacturing stages involve anode 401 and cathode 403 fabrication, cell assembly and cell finishing, and testing. The anode 401 and cathode 403 follow parallel tracks involving mixing (402) to form a slurry, coating (404) onto a conductive foil, pressing (406) to bond the coating to the foil, and cutting (408) to form the desired electrode dimensions. Following roll formation 410, the battery is assembled (420), filled with electrolyte, and sealed (430). Because LIB batteries are fabricated in a fully discharged state, the final stages of the process involve time-consuming cell finishing, which may include charge and discharge (440), evacuation and final sealing (450), further charge and discharge (460), and final aging (480) steps. Due to multiple time-consuming steps, the finishing process can take 20 to 30 days.

[0098] According to the embodiments described above, a lithium metal electrode can be fabricated in situ, thereby providing a lithium metal anode for an LMB in a fully charged state. According to the embodiment of FIG. 13, the above-described process for lithium metal anode fabrication can be vertically integrated into a cost- and energy-efficient manufacturing method for an LMB. As embodied in FIG. 13, the cathode 403 is still fabricated by the conventional method involving mixing (402), coating (404), and pressing (406). However, the working anode is now formed by electrolysis 405 according to the process embodied in FIG. 1, which involves covering the electrolytic cell with an overlying atmosphere 2, applying a constant current to the electrolytic cell 4, and passing Li across a lithium-selective membrane 6. + and Li metal 8 is + and fabricating a Li metal battery 12 by steps involving pouch formation (412), cell assembly (420), cell filling and sealing (430), and finishing steps (490). Cell assembly 420 involves assembling a casing with contents including a working anode and other components to form a lithium metal battery, and sealing the casing to isolate the contents from reactants present in the air.

[0099] 13, LMB fabrication in accordance with the present invention is a vertically integrated process that replaces the anode fabrication process with an in-situ low-temperature electrodeposition process, utilizing an aqueous lithium salt solution as the feedstock, with electrodeposition occurring through a lithium-ion selective membrane to produce a high-purity lithium metal anode that is resistant to dendrite formation. Because the lithium metal negative electrode is fabricated in a fully charged state, the lengthy formation process required for lithium-ion batteries is not required.

[0100] The use of lithium ion-selective membranes and high current densities allows relatively inexpensive impure raw materials, such as LiSO, to be used for electrodeposition, saving energy and reducing costs. Impurities in the lithium metal anode are further reduced by conducting the electrodeposition entirely in an overlying atmosphere substantially free of lithium reactants (including nitrogen, oxygen, ozone, oxides of nitrogen, sulfur and phosphorus, carbon dioxide, halogens, hydrogen halides, and water). In a preferred embodiment, the inert atmosphere is purified argon gas. In some embodiments, steps subsequent to electrodeposition, including cell assembly, electrolyte / cell filling, and sealing, are also conducted in an inert atmosphere. In other embodiments, only lithium electrodeposition occurs under an inert atmosphere, and the remainder of the battery manufacturing process is carried out in "dry air," which refers to air with less than 1% RH (relative humidity) (-45°C dew point). In a preferred embodiment, the temperature is maintained between about 20°C and about 30°C during LMB fabrication. In a preferred embodiment, the temperature is maintained between about 23°C and about 27°C during LMB fabrication.

[0101] It is understood that a variety of different LMB battery configurations are encompassed by the invention described above. Figure 14 embodies a single-cell battery configuration 14 shown as being fabricated with a battery case and showing electrical contacts to the anode 245 and cathode 255. Figure 15 embodies a dual-cell battery configuration 16 as being fabricated with a battery case and showing a single electrical contact to the anode 245 and two electrical contacts 255a, 255b to the cathode.

[0102] The embodiments of the present invention described above are intended to be examples only. Numerous variations and modifications will be apparent to those skilled in the art. All such changes and modifications are intended to be within the scope of the present invention, as defined in any appended claims.

Claims

1. 1. A method for making a lithium electrode, said method comprising: (1) Providing an electrolytic cell, the electrolytic cell comprising: a first chamber containing a positive electrode and an aqueous lithium salt solution in contact with the positive electrode; a second chamber containing a conductive substrate having a first surface; Including, the conductive substrate is configured as a negative electrode, the conductive substrate is stationary within the chamber during lithium metal electrodeposition, a first lithium ion selective membrane separates the first chamber from the second chamber, and a first non-aqueous electrolyte is disposed between the first surface of the conductive substrate and the first lithium ion selective membrane and is in physical contact with both the first surface of the conductive substrate and the first lithium ion selective membrane; the electrolytic cell is configured to allow the passage of lithium ions through the first lithium ion selective membrane between the first chamber and the second chamber and to prevent the passage of other chemical species between the first chamber and the second chamber; (2) covering the electrolytic cell with an overlying atmosphere, the overlying atmosphere being substantially free of lithium reactive components; (3) adjusting a variable voltage to maintain a constant current across the negative electrode and the positive electrode, thereby causing lithium ions to migrate from the first chamber to the second chamber, across the first lithium ion selective membrane and the first non-aqueous electrolyte, and electrodeposit a first layer of lithium on the first surface of the conductive substrate; Including, thereby forming the lithium electrode without producing nanorods, the first layer of lithium having an inner surface and an outer surface, the inner surface of the first layer of lithium being bonded to the conductive substrate; The constant current is 10 mA / cm ２ ~50mA / cm ２ wherein the constant current is applied for a time period between 1 minute and 60 minutes.

2. 10. The method of claim 1, wherein the overlying atmosphere contains no more than 10 ppm on a molar basis of lithium reactive components.

3. 10. The method of claim 1, wherein the overlying atmosphere contains no more than 10 ppm nitrogen on a molar basis.

4. 10. The method of claim 1, wherein the overlying atmosphere contains no more than 5 ppm nitrogen on a molar basis.

5. 10. The method of claim 1, wherein the conductive substrate comprises a plate having a first side and a second side, and the inner surface of the first layer of lithium is bonded to the first side of the conductive substrate.

6. The aqueous lithium salt solution is Li ２ SO ４ , Li ２ CO ３ 10. The method of claim 1, comprising providing a lithium salt selected from the group consisting of:

7. The aqueous lithium salt solution is Li ２ SO ４ The method of claim 1 , comprising:

8. The method of claim 1 , wherein the conductive substrate is selected from the group consisting of copper, aluminum, graphite-coated copper, and nickel.

9. 10. The method of claim 1, wherein the first lithium ion selective membrane comprises a polymer matrix and a plurality of ion-conducting particles disposed within the polymer matrix.

10. 10. The method of claim 1, wherein the first lithium ion selective membrane comprises a glass frit, with lithium ion conductive particles disposed within the glass frit.

11. 10. The method of claim 1, wherein the atmosphere comprises argon with a purity greater than 99.998 weight percent.

12. 10. The method of claim 1, wherein the lithium electrode has a specific capacity greater than 3,800 mAh of lithium per gram.

13. 1. A method for making a lithium electrode, said method comprising: (1) A gas-impermeable container is provided, the gas-impermeable container comprising: an overlying atmosphere, said overlying atmosphere being substantially free of lithium reactive components; an electrolytic cell comprising a first chamber; and The electrolytic cell is completely surrounded by the overlying atmosphere, and the first chamber comprises: a conductive substrate having a first surface, the conductive substrate being stationary within the electrolytic cell and configured as a negative electrode; a first positive electrode; a first aqueous lithium salt solution interposed between the first surface of the conductive substrate and the first positive electrode; a first lithium ion selective membrane configured to function as a solid-state electrolyte; Including, the first lithium ion selective membrane covers the first surface of the conductive substrate and forms a barrier separating the first aqueous lithium salt solution from the conductive substrate; the electrolytic cell is configured to allow the passage of lithium ions from the first aqueous lithium salt solution through the first lithium ion selective membrane to the surface of the first side of the conductive substrate, while preventing the passage of other chemical species; (2) adjusting a variable voltage to maintain a constant current across the negative electrode and the first positive electrode, thereby causing lithium ions from the first aqueous lithium salt solution to cross the first lithium ion selective membrane and electroplate a first layer of lithium onto the first surface of the conductive substrate, thereby forming the lithium electrode without producing nanorods; Including, the first layer of lithium has an inner surface and an outer surface, the inner surface bonded to the first surface of the conductive substrate and the outer surface bonded to the first lithium ion selective membrane, and the lithium electrode comprises the conductive substrate, the first layer of lithium, and the first lithium ion selective membrane; The constant current is 10 mA / cm ２ ~50mA / cm ２ wherein the constant current is applied for a time period between 1 minute and 60 minutes.

14. 1. A method of manufacturing a lithium metal battery, the method comprising: Producing a lithium electrode according to the method of claim 1; assembling a casing with contents including the lithium electrode configured as an anode and other components necessary to form the lithium metal battery; sealing said casing to isolate said contents of said casing from reactants present in air, thereby providing said lithium metal battery; A method comprising:

15. 15. The method of manufacturing of claim 14, wherein the method is performed in a single fabrication facility.

16. 1. A method of manufacturing a lithium metal battery, the method comprising: Producing a lithium electrode according to the method of claim 13; assembling a casing with contents including the lithium electrode configured as an anode and other components necessary to form the lithium metal battery; sealing said casing to isolate said contents of said casing from reactants present in air, thereby providing said lithium metal battery; A method comprising:

17. 17. The method of manufacturing of claim 16, wherein the method is performed in a single fabrication facility.

18. 20. The method of claim 17, wherein the method is carried out entirely under an atmosphere that is inert to chemical reaction with lithium.

19. the conductive substrate comprises a plate having a first surface and a second surface; the first non-aqueous electrolyte is disposed between the first side of the conductive substrate and the first lithium ion selective membrane, the first non-aqueous electrolyte being in physical contact with both the first side of the conductive substrate and the first lithium ion selective membrane; The electrolytic cell comprises: a third chamber containing a second lithium ion selective membrane and a second non-aqueous electrolyte, the second non-aqueous electrolyte being disposed between the second side of the conductive substrate and the second lithium ion selective membrane and in physical contact with both the second side of the conductive substrate and the second lithium ion selective membrane; a fourth chamber containing a second positive electrode and a second aqueous lithium salt solution in contact with the second positive electrode; further comprising the second lithium ion selective membrane separating the third chamber from the fourth chamber; the electrolytic cell is further configured to allow passage of lithium ions through the second lithium ion selective membrane between the fourth chamber and the third chamber and to prevent passage of other chemical species between the fourth chamber and the third chamber; the constant current further causes lithium ions to traverse the second lithium ion selective membrane and the second non-aqueous electrolyte from the fourth chamber to the third chamber and electroplate a second layer of lithium onto the second surface of the conductive substrate, thereby forming the lithium electrode without producing nanorods; the lithium electrode comprises the conductive substrate, the first layer of lithium, and the second layer of lithium, the first layer of lithium having an inner surface and an outer surface, the inner surface being bonded to the first surface of the conductive substrate, the second layer of lithium having an inner surface and an outer surface, the inner surface of the second layer of lithium being bonded to the second surface of the conductive substrate; The constant current is 10 mA / cm ２ ~50mA / cm ２ and the constant current is applied for a time period between 1 minute and 60 minutes.

20. the conductive substrate comprises a plate having a first surface and a second surface, the first surface being covered with the first lithium ion selective membrane and the second surface being covered with a second lithium ion selective membrane, the first and second lithium ion selective membranes being configured to function as a solid-state electrolyte; the electrolytic cell comprises a second positive electrode and a second chamber containing a second aqueous lithium salt solution in contact with the second positive electrode and the second lithium ion selective membrane; the electrolytic cell is configured to allow passage of lithium ions through the second lithium ion selective membrane between the second chamber and the second side of the conductive substrate and to prevent passage of other chemical species between the second chamber and the second side of the conductive substrate; the constant current causes lithium ions to migrate from the second chamber across the second lithium ion selective membrane and electroplate a second layer of lithium onto the second surface of the conductive substrate, thereby forming the lithium electrode without producing nanorods; the lithium electrode comprises the conductive substrate, the first layer of lithium, and the second layer of lithium, the first layer of lithium having an inner surface and an outer surface, the inner surface of the first layer of lithium bonded to the first surface of the conductive substrate, the outer surface of the first layer of lithium bonded to the first lithium ion selective membrane, the second layer of lithium having an inner surface and an outer surface, the inner surface of the second layer of lithium bonded to the second surface of the conductive substrate, and the outer surface of the second layer of lithium bonded to the second lithium ion selective membrane; The constant current is 10 mA / cm ２ ~50mA / cm ２ and the constant current is applied for a time period between 1 minute and 60 minutes.

21. 10. The method of claim 1, wherein the first lithium ion selective membrane is stationary within the electrolytic cell, and as the first layer of lithium forms, the first layer of lithium displaces non-aqueous electrolyte from a space between the conductive substrate and the first lithium ion selective membrane, thereby bonding the inner surface of the first layer of lithium to the conductive substrate and bonding the outer surface of the first layer of lithium to the first lithium ion selective membrane, thereby forming a lithium metal electrode comprising the conductive substrate and the first layer of lithium, the inner surface of the first layer of lithium bonded to the conductive substrate and the outer surface of the first layer of lithium bonded to the first lithium ion selective membrane, and the first lithium ion selective membrane configured to function as a solid-state electrolyte when the lithium metal electrode is incorporated into a galvanic cell.

22. The first and second lithium ion selective membranes are immobile within the electrolytic bath, and as the first layer of lithium forms, the first layer of lithium displaces the first non-aqueous electrolyte from the space between the first surface of the conductive substrate and the first lithium ion selective membrane, thereby bonding the inner surface of the first layer of lithium to the first surface of the conductive substrate and bonding the outer surface of the first layer of lithium to the first lithium ion selective membrane, and as the second layer of lithium forms, the second layer of lithium displaces the second non-aqueous electrolyte from the space between the second surface of the conductive substrate and the second lithium ion selective membrane, thereby bonding the inner surface of the second layer of lithium to the second surface of the conductive substrate.

20. The method of claim 19, wherein the first and second layers of lithium are bonded to the conductive substrate and the outer surface of the second layer of lithium is bonded to the second lithium ion selective membrane, thereby forming a lithium metal electrode comprising the conductive substrate and the first and second layers of lithium, the inner surface of the first layer of lithium bonded to the first surface of the conductive substrate and the outer surface of the first layer of lithium bonded to the first lithium ion selective membrane, and the inner surface of the second layer of lithium is bonded to the second surface of the conductive substrate and the outer surface of the second layer of lithium is bonded to the second lithium ion selective membrane, and the first and second lithium ion selective membranes are configured to function as a solid-state electrolyte when the lithium metal electrode is incorporated into a galvanic cell.

23. The constant current is 25 mA / cm ２ ~50mA / cm ２ 2. The method for producing a lithium electrode according to claim 1, wherein

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