Dry electrode fabrication for solid energy storage devices

Abstract

The present invention provides a method for manufacturing electrode films for solid-state batteries, a method for manufacturing electrode blocks for solid-state batteries, and a self-supporting electrolyte film. [Solution] A method for manufacturing an electrode film for a solid-state battery comprises the steps of: preparing a powder mixture comprising at least one type of electrode active material, at least one type of fibrillable binder, and at least one type of dry electrolyte powder, wherein the at least one type of dry electrolyte powder is 5 to 30% by weight of the powder mixture; fibrillating the at least one type of fibrillable binder in the powder mixture by exposing the powder mixture to a shearing force; and pressing the powder mixture to form a self-supporting film.

Description

[Background technology]

[0001] [Cross-references to related applications] This application is a continuation-in-part application of U.S. Patent Application No. 17 / 492,458, filed on 1 October 2021, entitled “DRY ELECTRODE MANUFACTURE FOR SOLID STATE ENERGY STORAGE DEVICES,” the full disclosure of which is incorporated herein by reference. [Description of research and development funded by the federal government]

[0002] Not applicable

[0003] 1. Technical field

[0004] This disclosure relates, in general, to the manufacture of energy storage devices such as lithium-ion batteries, and more specifically, to a dry process for the manufacture of solid-state batteries.

[0005] 2. Related Technologies

[0006] Due to safety concerns surrounding the use of flammable liquid electrolytes in lithium-ion batteries and other energy storage devices, and to take advantage of the high energy density achievable using lithium metal anodes, there is considerable interest in the development of solid-state batteries and other energy storage devices. In solid-state batteries, conventional liquid electrolytes and separators are replaced with ceramic or solid polymer electrolytes. Unfortunately, electrolyte materials tend to be affected by N-methylpyrrolidone (NMP) or other solvents used to form the solid electrolyte membrane by using wet coating methods, resulting in reduced battery performance. Furthermore, current techniques for assembling solid-state batteries result in a substantial boundary layer between the solid electrolyte and electrodes, making it difficult for electrolyte ions to pass through and thus increasing battery resistance. [Overview of the project]

[0007] This disclosure envisions various methods and devices for overcoming the aforementioned drawbacks associated with related technologies. One embodiment of the embodiments of this disclosure is a method for manufacturing an electrode block for a solid-state battery. The method may comprise the steps of: providing the electrode film having a current collector on a first surface of the electrode film; coating a layer of dry electrolyte powder on a second surface of the electrode film opposite to the first surface; and pressing the dry electrolyte powder coated on the electrode film to produce a solid electrolyte layer on the electrode film.

[0008] The steps of providing the electrode film having the current collector may include: preparing a powder mixture comprising at least one type of electrode active material and at least one type of fibrillable binder; fibrillating the at least one type of fibrillable binder in the powder mixture by exposing the powder mixture to a shear force; pressing the powder mixture to form a self-supporting film; and laminating the self-supporting film onto the current collector. The powder mixture may further comprise at least one type of dry electrolyte powder.

[0009] Another embodiment of the embodiments of the present disclosure is a method for manufacturing a solid-state battery. The method may include the steps of: providing a first electrode film having a first surface and a second surface opposite to the first surface; providing a second electrode film having a first surface and a second surface opposite to the first surface; coating the second surface of the first electrode film with a layer of dry electrolyte powder; placing the second surface of the second electrode film on the layer of dry electrolyte powder; and pressing the first electrode film, on which the layer of dry electrolyte powder is coated, together with the second electrode film to produce a solid-state battery comprising the first electrode film, the second electrode film, and a solid electrolyte layer between them.

[0010] Either or both of the steps of providing the first electrode film and the step of providing the second electrode film may include preparing a powder mixture comprising at least one type of electrode active material and at least one type of fibrillatable binder, fibrillating the at least one type of fibrillatable binder in the powder mixture by subjecting the powder mixture to a shearing force, and pressing the powder mixture into a self-supporting film. The powder mixture may further comprise at least one type of dry electrolyte powder.

[0011] The method may further include laminating the first electrode film on a first current collector with the first current collector on the first surface of the first electrode film, and laminating the second electrode film on a second current collector with the second current collector on the first surface of the second electrode film. The step of laminating the first electrode film and the step of laminating the second electrode film may be performed before the coating step or after the pressing step.

[0012] Another aspect of an embodiment of the present disclosure is a method of manufacturing an electrode film for a solid-state battery. The method may include preparing a powder mixture comprising at least one type of electrode active material, at least one type of fibrillatable binder, and at least one type of dry electrolyte powder, wherein the at least one type of dry electrolyte powder is 5 to 30% by weight of the powder mixture, fibrillating the at least one type of fibrillatable binder in the powder mixture by subjecting the powder mixture to a shearing force, and pressing the powder mixture into a self-supporting film.

[0013] The method may include activating the at least one type of fibrillatable binder by adding a solvent to the powder mixture before the fibrillating step.

[0014] The method may include a step of heating the powder mixture to 70°C or higher to activate the at least one type of fibrillating binder, prior to the fibrillation step.

[0015] The powder mixture may comprise an additive solution having a polymer additive and a liquid carrier, wherein the additive solution is less than 5% by weight of the powder mixture.

[0016] The powder mixture may comprise a conductive paste having a polymer additive, a liquid carrier, and a conductive material, wherein the conductive paste constitutes less than 5% by weight of the powder mixture.

[0017] Another embodiment of the embodiments of the present disclosure is a self-supporting electrode film. The self-supporting electrode film may comprise at least one type of electrode active material, at least one type of fibrillable binder, and at least one type of dry electrolyte powder in an amount of 5 to 30% by weight of the self-supporting electrode film.

[0018] Another embodiment of the embodiments of the present disclosure is a method for producing an electrolyte membrane for a solid-state battery. The method may comprise the steps of: preparing a powder mixture comprising at least one type of fibrillable binder and at least one type of dry electrolyte powder, wherein the at least one type of dry electrolyte powder constitutes the majority of the powder mixture by weight (e.g., 80% or more by weight of the powder mixture, e.g., 80-97% by weight or 80-99% by weight, preferably 95-99% by weight); fibrillating the at least one type of fibrillable binder in the powder mixture by exposing the powder mixture to a shearing force; and pressing the powder mixture to form a self-supporting membrane.

[0019] The method may include a step of adding a solvent to the powder mixture to activate the at least one type of fibrillating binder prior to the fibrillation step.

[0020] The method may include a step of heating the powder mixture to 70°C or higher to activate the at least one type of fibrillating binder, prior to the fibrillation step.

[0021] The powder mixture may comprise an additive solution having a polymer additive and a liquid carrier, wherein the additive solution is less than 5% by weight of the powder mixture.

[0022] Another embodiment of the embodiments of the present disclosure is a method for manufacturing an electrode block for a solid-state battery. The method may comprise the steps of: performing the above method for manufacturing the electrolyte membrane; providing the electrode membrane (having or not having a current collector); and laminating the self-supporting electrolyte membrane onto the electrode membrane.

[0023] Another embodiment of the embodiments of the present disclosure is a self-supporting electrolyte membrane. The self-supporting electrolyte membrane may comprise at least one type of fibrillable binder and at least one type of dry electrolyte powder. The at least one type of dry electrolyte powder may constitute the majority of the self-supporting electrolyte membrane by weight. For example, the dry electrolyte powder may be 80% by weight or more of the self-supporting electrolyte membrane, for example, 80-97% by weight or 80-99% by weight, preferably 95-99% by weight.

[0024] Another embodiment of the embodiments of the present disclosure is a method for manufacturing an electrode block for a solid-state battery. The method may include the step of laminating the self-supporting electrolyte membrane onto an electrode film. [Brief explanation of the drawing]

[0025] These and other features and advantages of the various embodiments disclosed herein will be better understood with respect to the following description and drawings, in which similar figures refer to similar parts throughout.

[0026] [Figure 1] This is a diagram of an apparatus for manufacturing electrode blocks for solid-state batteries.

[0027] [Figure 1A] This is a magnified view of the electrode block.

[0028] [Figure 2] This is a diagram of an apparatus for manufacturing solid-state batteries.

[0029] [Figure 2A] This is a magnified view of a solid-state battery.

[0030] [Figure 3] This is the workflow for manufacturing electrode blocks.

[0031] [Figure 4] This is a workflow for manufacturing solid-state batteries.

[0032] [Figure 5] This is a workflow for manufacturing an electrode film, and is an exemplary sub-workflow of step 310 in Figure 3, step 410 in Figure 4, or step 420 in Figure 4.

[0033] [Figure 6] This is a workflow for manufacturing electrolyte membranes. [Modes for carrying out the invention]

[0034] This disclosure encompasses various embodiments of solid-state batteries and electrodes, as well as methods for manufacturing them and intermediate products. In relation to the accompanying drawings, the embodiments for carrying out the invention described below are intended to describe multiple currently contemplated embodiments and are not intended to represent only one form in which the disclosed invention may be developed or utilized. This description describes the functions and features in relation to the exemplary embodiments. However, it should be understood that the same or equivalent functions may be achieved by different embodiments that are also intended to be included within the scope of this disclosure. It should be further understood that the use of relational terms such as "first," "second," and "and so on" is used simply to distinguish one subject from another, without necessarily requiring or suggesting any actual such relationship or order between such subjects.

[0035] Figure 1 shows an apparatus 10 for manufacturing electrode blocks 100 for solid-state batteries. Figure 1A is an enlarged view of an electrode block 100, which may comprise an electrode film 110 and a solid electrolyte layer 120 laminated thereon. The electrode block 100 may be stacked and / or wound together with additional electrode blocks 100 to manufacture multilayer batteries such as cylindrical or prismatic cells. As shown, the apparatus 10 may comprise one or more pieces of roll-to-roll process equipment, for example, a first spool 12 on which the electrode film 110 may be first wound as a roll, a second spool 14 on which the final electrode block 100 may be wound, and one or more rollers 16 (e.g., drive and / or idler rollers) for carrying the electrode film 110 through the apparatus 10 from the first spool 12 to the second spool 14. Unlike conventional solid-state battery manufacturing equipment, the apparatus 10 in Figure 1 may include a scatter coater 11 or other means for coating one side 114 of the electrode film 110 with a layer of dry electrolyte powder 119. After this coating, the dry electrolyte powder 119 may be pressed by a roller press or calender 18 to produce a solid electrolyte layer 120 on top of the electrode film 110. In this way, the solid electrolyte layer 120 can be formed in a dry process, avoiding the significant amounts of NMP or other solvents used in conventional slurry-based processes that could otherwise degrade the performance of the solid electrolyte. Furthermore, since the solid electrolyte layer 120 is formed directly on top of the electrode film 110 rather than being subsequently stacked on top of it, the resulting boundary between the electrode film 110 and the solid electrolyte layer 120 may allow electrolyte ions to pass through more easily, reducing battery resistance.

[0036] The electrode film 110 may be either a cathode film or an anode film, and may contain an active material layer suitable for the cathode or anode, respectively. To assemble a multilayer battery, electrode blocks 100 having cathode and anode electrode films 110 may be stacked in an alternating manner, typically such that the solid electrolyte layer 120 separates each cathode from adjacent anodes and each anode from adjacent cathodes. For ease of illustration, the electrode film 110 is shown as a single layer, i.e., having only an active material layer (which may be, for example, 50 μm to 350 μm), with dry electrolyte powder 119 coated on one of its surfaces 114. However, a current collector (which may be, for example, 8 μm to 30 μm), such as an aluminum metal sheet in the case of the cathode electrode film 110, or a copper metal sheet in the case of the anode electrode film 110, may be laminated on the opposite surface 112. Although not shown separately, this current collector may be present for the process illustrated in Figure 1, helping to provide stability during the pressing of the dry electrolyte powder 119 into the solid electrolyte layer 120, and may be within the final electrode block 100 shown in Figure 1A. It is also intended, though usually less practical, that the current collector may be laminated onto the electrode block 100 after the process of Figure 1 rather than before.

[0037] Figure 2 shows an apparatus 20 for manufacturing a solid-state battery 200. Figure 2A is an enlarged view of the solid-state battery 200, which may comprise a first electrode film 210, a solid electrolyte layer 220, and a second electrode film 230, in the order described as shown. The apparatus 20 may be largely the same as the apparatus 10 in Figure 1, and may similarly include a first spool 12 on which the first electrode film 210 can be initially wound as a roll, a second spool 14 on which the final product, in this case the solid-state battery 200, can be wound, one or more rollers 16, a roller press or calendar 18, and a scatter coater 11 or other means. The apparatus 20 may differ from the apparatus 10 in that it adds a third spool 22 on which the second electrode film 230 can be initially wound as a roll. In the apparatus 20, the scatter coater 11 can coat a layer of dry electrolyte powder 119 onto one surface 214 of the first electrode film 210, and after the coating, one surface 234 of the second electrode film 230 can be placed on the layer of dry electrolyte powder 119. Using a roller press or a calender 18, the first electrode film 210, on which the layer of dry electrolyte powder 119 is coated, can then be pressed together with the second electrode film 230 to produce a solid-state battery 200 comprising the first electrode film 210, the second electrode film 230, and a solid electrolyte layer 220 between them.

[0038] While the apparatus 10 shown in Figures 1 and 1A can produce individual electrode blocks 100 for use in multilayer batteries, the apparatus 20 in Figures 2 and 2A can produce a final single-layer solid-state battery 200 having only one cathode and one anode. Such a single-layer solid-state battery 200 can be packaged, for example, as a pouch cell or button cell. Note that one of the first and second electrode layers 210, 230 may be the cathode and the other the anode. That is, the dry electrolyte powder 119 may be coated onto either the cathode or the anode before being sandwiched and pressed by the other to form the solid electrolyte layer 220.

[0039] Here, for the sake of illustration, the electrode film 210 is shown as a single layer, i.e., having only an active material layer, with the dry electrolyte powder 119 coated on one of its surfaces 214. Similarly, the electrode film 230 is shown as having only an active material layer, with one surface 234 positioned in contact with the dry electrolyte powder 119. As described above, current collectors such as aluminum metal sheets in the case of cathode electrode films 210, 230, or copper metal sheets in the case of anode electrode films 210, 230, may be laminated on the opposite surfaces 212, 232, and it should be understood that such current collectors may be present in the process illustrated in Figure 2 and in the final solid-state battery 200 shown in Figure 2A. However, some single-cell batteries 200, such as coin cells that utilize the metal of the case for this purpose, do not need to have current collectors, so it is intended that the process in Figure 2 may actually proceed without current collectors on the electrode films 210, 230. In this regard, the process in Figure 2 may have a lower actual need for the metal current collector layer, as the additional electrode film 230 can provide some degree of stability during pressing compared to the process in Figure 1. Therefore, when the current collectors are used in the final solid-state battery 200, the electrode films 210, 230 can be laminated on the respective current collectors either before (and therefore before) or after the coating with the dry electrolyte powder 119.

[0040] Figure 3 shows a workflow for manufacturing an electrode block, such as the electrode block 100 shown in Figure 1A. The workflow may begin with a step (step 310) of providing an electrode film 110, which can typically be laminated onto a current collector as described above. The electrode film 110 can be produced by any method, including, for example, slurry coating, extrusion, and dry methods. Advantageously, a dry method may be used, such as any of the methods described in the inventors' own prior patents and patent applications, including U.S. Patent No. 10,069,131 entitled "Electrode for Energy Storage Devices and Method of Making Same," U.S. Patent Application Publication No. 2020 / 0388822 entitled "Dry Electrode Manufacture by Temperature Activation Method," U.S. Patent Application No. 17 / 014,862 entitled "Dry Electrode Manufacture with Lubricated Active Material Mixture," and U.S. Patent Application No. 17 / 097,200 entitled "Dry Electrode Manufacture with Composite Binder," the full disclosures of each of these are incorporated herein by reference as a whole.As will be described in more detail below, the electrode film 110 may be produced by preparing a powder mixture containing at least one type of electrode active material (e.g., lithium metal oxide in the case of the cathode, or graphite in the case of the anode) and at least one type of fibrillable binder, for example, polytetrafluoroethylne (PTFE), polyvinylpyrrolidone (PVP), polyvinylidene fluoride (PVDF), polyethylene oxide (PEO), or carboxymethylcellulose (CMC); fibrillating the binder by exposing the powder mixture to a shear force; and pressing the powder mixture to form a self-supporting film that can then be laminated on a current collector.

[0041] With the electrode film 110 preferably manufactured or otherwise provided with a current collector on its first surface 112, the workflow in Figure 3 may proceed to a step (step 320) of coating a layer of dry electrolyte powder 119 onto a second surface 114 of the electrode film 110 opposite to the first surface 112. As illustrated in Figure 1, the coating of the dry electrolyte powder 119 onto the electrode film 110 may be part of a roll-to-roll process exemplified by apparatus 10, in which a scatter coater 11 coats the electrode film 110 with dry electrolyte powder 119 as it is carried by one or more rollers 16 from a first spool 12 to a second spool 14. The workflow may end in a step (step 330) of pressing the coated dry electrolyte powder 119 onto the electrode film 110 to produce a solid electrolyte layer 120 on the electrode film 110. As shown in Figure 1, for example, as the dry electrode film 110 passes through the apparatus 10 from the first spool 12 to the second spool 14, a roller press or calender 18 can press the dry electrolyte powder 119 on the electrode film 110 to produce a solid electrolyte layer 120. The completed electrode block 100, which can be used to produce a multilayer battery as described above, may be as shown in Figure 1A (the current collector is omitted for ease of illustration).

[0042] Figure 4 shows a workflow for manufacturing a solid-state battery, such as the solid-state battery 200 shown in Figure 2A. The workflow may begin with steps 410 and 420 of providing a first electrode film 210 and a second electrode film 230. Similar to the electrode film 110 described above, the electrode films 210, 230 may be produced by any method including a dry method, which includes, for example, a slurry coating method, an extrusion method, and any of the methods described in the inventors' own prior patents and patent applications, such as those incorporated by reference above. In particular, as will be described in more detail below, each of the electrode films 210, 230 may be produced by preparing a powder mixture containing at least one type of electrode active material (e.g., lithium metal oxide in the case of the cathode, or graphite in the case of the anode) and at least one type of fibrillable binder, e.g., PTFE, PVP, PVDF, PEO, or CMC; fibrillating the binder by exposing the powder mixture to a shear force; and pressing the powder mixture to form a self-supporting film that can then be laminated on a current collector. If the first electrode film 210 is composed of a cathode active material, the second electrode film 230 may be composed of an anode active material. If the first electrode film 210 is composed of an anode active material, the second electrode film 230 may be composed of a cathode active material.

[0043] With electrode films 210, 230 optionally manufactured or otherwise provided with their respective current collectors on their first surfaces 212, 232, the workflow in Figure 4 may proceed to a step (step 430) of coating a layer of dry electrolyte powder 119 onto the second surface 214 of the first electrode film 210 opposite to the first surface 212. As illustrated in Figure 2, the coating of the dry electrolyte powder 119 onto the electrode film 210 may be part of a roll-to-roll process exemplified by apparatus 20, in which a scatter coater 11 coats the dry electrolyte powder 119 onto the first electrode film 210 (which may be either the cathode or the anode) as the first electrode film 210 is carried by one or more rollers 16 from the first spool 12 to the second spool 14. After the dry electrolyte powder 119 has been coated onto the first electrode film 210, the workflow may proceed to the step of placing the second electrode film 230 on top of the layer of dry electrolyte powder 119. In particular, the second face 234 of the second electrode film 230 (i.e., the face opposite to the first face 232 having an optional current collector) may be positioned close to the layer of dry electrolyte powder 119, as shown in Figure 2, such that the first and second electrode films 210, 230 sandwich the layer of dry electrolyte powder 119 between them. The workflow may proceed to the step (step 450) of pressing the first electrode film 210, on which the layer of dry electrolyte powder 119 is coated, together with the second electrode film 230 (for example, using a roller press or a calender 18) to produce a solid-state battery 200 including the first electrode film 210, the second electrode film 230, and the solid electrolyte layer 220 between them. A completed solid-state battery 200, which may be a single-layer battery as described above, may be as shown in Figure 2A.

[0044] The working flow of FIG. 4 may end with the steps of laminating the first electrode film 210 on the first current collector (for example, an aluminum metal sheet in the case of a cathode, or a copper metal sheet in the case of an anode), and similarly, laminating the second electrode film 230 on the second current collector (steps 460, 470). These steps may follow step 450 as shown in FIG. 4, and the completed solid battery 200 is then laminated on the respective current collectors on both of the outer surfaces 212, 232. Alternatively, one or both of steps 460 and 470 may precede step 430 such that the electrode films 210, 230 are laminated on the respective current collectors before being coated with the dry electrolyte powder 119 as described above. In this case, FIG. 2A omits such an optional current collector for ease of illustration. Alternatively, steps 460 and 470 may be completely omitted, which may be useful when manufacturing certain button cells that do not use current collectors.

[0045] The dry electrolyte powder 119 used in either of the working flows of FIGS. 3 and 4 (and by either of the apparatuses 10, 20) is mainly (for example, 80 - 100% by weight), garnet - structured oxides, such as lithium lanthanum zirconium oxide (LLZO) having various dopants (for example, Li 6.5 La3Zr2O 12 or Li7La3Zr2O 12 ), lithium lanthanum zirconium tantalum oxide (LLZTO) (for example, Li 6.4 La3Z 1.4 Ta 0.6 O 12 ), lithium lanthanum zirconium niobium oxide (LLZNbO) (for example, Li 6.5 La3Zr 1.5 Nb 0.5 O 12), lithium lanthanum zirconium tungsten oxide (LLZWO) (for example, Li 6.3 La3Zr 1.65 W 0.35 O 12 ), perovskite structure oxides, for example, lithium lanthanum titanate (LLTO) (for example, Li 0.5 La 0.5 TiO3, Li 0.34 La 0.56 TiO3, or Li 0.29 La 0.57 TiO3) or lithium aluminum titanium phosphate (LATP) (for example, Li 1.4 Al 0.4 Ti 1.6 (PO4)3) Lithium superionic conductor Li 2+2x Zn 1-x GeO4 (lithium superionic conductor: LISICON), for example, lithium aluminum titanium phosphate (LATP) (for example, Li 1.3 Al 0.3 Ti 1.7 (PO4)3) Lithium aluminum germanium phosphate (LAG or sodium superionic conductor, i.e., NASICON type LAGP) (e.g., Li 1.5 Al 0.5 Ge 1.5 (PO4)3 or Li 1.5 Al 0.5 Ge 1.5 P3O 12 ) or phosphoric acid, for example, lithium titanium phosphate (LTPO) (e.g., LiTi2(PO4)3), lithium germanium phosphate (LGPO) (e.g., LiGe2(PO4)3), lithium phosphate (LPO) (e.g., γ-Li3PO4 or Li7P3O 11), or ceramics such as lithium phosphorus oxynitride (LiPON). As another example, the dry electrolyte powder 119 may be mainly (e.g., 80-100% by weight) polymers such as PEO, PEO-PTFE, PEO-LiTFSi, PEO-LiTFSi / LLZO, PEO-LiClO4, PEO-LiClO4 / LLZO, poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate (PEDOT:PSS), polyphenylene oxide (PPO), polyethylene glycol (PEG), polyether polymers, polyester polymers, nitrile polymers, polysiloxane polymers, polyurethanes, poly(bis((methoxyethoxy)ethoxy)phosphazene):MEEP), or polyvinyl alcohol (PVA). As another example, the dry electrolyte powder 119 mainly consists of (e.g., 80-100% by weight) lithium sulfide (LS) (e.g., Li2S), vitreous lithium sulfide phosphorus sulfide (LSPS) (e.g., Li2S-P2S5), vitreous lithium sulfide boron sulfide (LSBS) (e.g., Li2S-B2S3), vitreous lithium sulfide silicon sulfide (LSSiS) (e.g., Li2S-SiS2), lithium germanium sulfide (LGS) (e.g., Li4GeS4), lithium phosphorus sulfide (LPS) (e.g., Li3PS4, e.g., 75Li2S-25P2S5 or Li7P3S) 11For example, 70Li2S-30P2S5), lithium silicon phosphorus tin sulfide (LSPTS) (for example, Li x (SiSn)P y S z ), silver-germanium ore Li6PS5X(X=Cl,Br) (e.g., LPSBr, e.g., Li6PS5Br, LPSCl, e.g., Li6PS5Cl, LPSClBr, e.g., Li6PS5Cl 0.5 Br 0.5 , or LSiPSCl, for example, Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 ) or thio-LISICON (e.g., LGPS, e.g., Li 10 GePS 12 These could be sulfides such as ).

[0046] Figure 5 is a workflow for manufacturing electrode films such as the electrode films 110, 210, and 230 described above. Therefore, Figure 5 can function as an exemplary subworkflow of step 310 in Figure 3, step 410 in Figure 4, or step 420 in Figure 4. In particular, Figure 5 provides one example of a dry method for producing cathode or anode electrode films 110, 210, and 230, which can further be used to produce electrode blocks 100 of a multilayer battery according to the workflow of Figure 3, or to produce a single-layer battery according to the workflow of Figure 4. As stated above, producing electrode films 110, 210, and 230 by a dry method may generally involve preparing a powder mixture containing at least one type of electrode active material and at least one type of fibrillable binder, fibrillating the binder by exposing the powder mixture to shear force, and pressing the powder mixture to form self-supporting films that can then be laminated on a current collector. More specifically, the workflow in Figure 5 may begin with the step (step 510) of preparing the powder mixtures for electrode films 110, 210, and 230. The electrode active material may constitute the majority of the powder mixture, for example, 82–99% (e.g., 94% by weight) of the powder mixture. For the cathode, the electrode active material may be a lithium metal oxide, such as lithium manganese oxide (LMO), lithium nickel manganese cobalt oxide (NCM), lithium nickel cobalt aluminum oxide (NCA), or lithium nickel manganese oxide (LMNO). For the anode, the electrode active material may be graphite, silicon dioxide (SiO2), or a mixture of the two. Depending on the conductivity of the active material, a conductive material may be added to the powder mixture in an amount of, for example, 0–10% (e.g., 4% by weight).Exemplary conductive materials may include activated carbon, acetylene black, Ketjenblack, or conductive carbon black such as super P (for example, carbon black marketed under the trademark name SUPER P® by Imerys Graphite & Carbon GmbH in Switzerland), carbon nanotubes (CNTs), graphite particles, conductive polymers, or combinations thereof.

[0047] To form electrode films 110, 210, and 230 by a dry method (and thus avoid the long drying times associated with conventional slurry coating and extrusion methods), the powder mixture may further include at least one type of fibrillable binder, such as polytetrafluoroethylene (PTFE), polyvinylpyrrolidone (PVP), polyvinylidene fluoride (PVDF), polyethylene oxide (PEO), or carboxymethylcellulose (CMC), as described in U.S. Patent Application No. 17 / 097,200, entitled "Dry Electrode Manufacture with Composite Binder," which is incorporated by reference above. The fibrillable binders may be characterized by their soft, flexible stiffness and, in particular, their extensibility, becoming longer and thinner and exhibiting a fibrous state when subjected to shear forces. Thanks to the use of one or more fibrillating binders that can be further chemically or thermally activated to increase their flexibility, as described below, the powder mixture can be pressed into a self-supporting film without damage and without the excessive use of solvents such as NMP.

[0048] As described in more detail in U.S. Patent Application No. 17 / 014,862, entitled “Dry Electrode Manufacture with Lubricated Active Material Mixture,” incorporated by reference above, a powder mixture containing an electrode active material can be lubricated by mixing it in a polymer-containing additive solution or conductive paste before adding a binder. For example, the powder mixture may include an additive solution containing a polymer additive and a liquid carrier in addition to the electrode active material (and the fibrillable binder subsequently added). The additive solution may be less than 5% by weight of the powder mixture so that the powder mixture may remain a dry powder despite the relatively small amount of liquid added. For example, the final powder mixture containing the electrode active material, any conductive material, a fibrillable binder, and the additive solution, as well as any electrolyte powder (see below), may have a total solid content of more than 95% by weight. The polymer additive, which may be 0.5% to 10% by weight of the additive solution, may be a polymer compound, a surfactant, or a high-viscosity liquid (e.g., mineral oil or wax), such as those known to be used as dispersants or binders for carbon nanotubes. See, for example, U.S. Patent No. 8,540,902, which provides exemplary dispersants and polymer binders including polyethylene, polypropylene, polyamide, polyurethane, polyvinylidene fluoride, thermoplastic polyester resins, polyvinylpyrrolidone, polystyrene sulfonate, polyphenylacetylene, polymeth-phenylenevinylene, polypyrrole, polyp-phenylenebenzobisoxazole, natural polymers, amphiphilic substances in aqueous solutions, anionic aliphatic surfactants, sodium dodecyl sulfate, cyclic lipopeptide biosurfactants, water-soluble polymers, polyvinyl alcohol sodium dodecyl sulfate, polyoxyethylene surfactants, polyvinylidene fluoride (PVDF), carboxymethylcellulose (CMC), hydroxyethylcellulose polyacrylic acid, polyvinyl chloride, and combinations thereof. Another exemplary polymer additive may be styrene-butadiene rubber (SBR).The liquid carrier used to generate the additive solution may be aqueous or non-aqueous, and may include, for example, one or more chemical substances selected from the group consisting of n-methylpyrrolidone, hydrocarbons, acetates, alcohols, glycols, ethanol, methanol, isopropanol, acetone, diethyl carbonate, and dimethyl carbonate.

[0049] Alternatively, the powder mixture may include a conductive paste containing polymer additives, a liquid carrier, and a conductive material, in addition to the electrode active material (and the subsequently added fibrillable binder). Similar to the additive solution described above, the conductive paste may be less than 5% by weight of the powder mixture. For example, a final powder mixture containing the electrode active material, the fibrillable binder, and the conductive paste (typically without a separate conductive material used in the powder mixture), as well as any electrolyte powder (see below), may have a total solid content exceeding 95% by weight. The conductive paste may differ from the additive solution in that it contains, for example, 1 to 20% by weight, preferably 2 to 15% by weight, and more preferably 5 to 10% by weight of the conductive paste. The conductive paste may be a CNT paste conventionally used to enhance electrical conductivity in a wet mixture used in a coating method, for example, as exemplified by U.S. Patent No. 8,540,902. As one example, a conductive paste may consist of 3.08% PVP as a polymer additive, 91.67% NMP as a liquid carrier, and 6.25% carbon nanotubes as a conductive material.

[0050] In the final electrode block 100 or solid-state battery 200, the powder mixture may contain at least one type of dry electrolyte powder so that the resulting electrode films 110, 210, and 230 can more easily exchange electrolyte ions with the solid electrolyte layers 120 and 220, thereby reducing battery resistance. The amount of dry electrolyte powder in the powder mixture may be, for example, 5 to 30% by weight. The dry electrolyte powder contained in the powder mixture may be the same as or different from the dry electrolyte powder 119 used to form the solid electrolyte layers 120 and 220, and may be, for example, any of the materials listed above with respect to the dry electrolyte powder 119.

[0051] With a powder mixture prepared comprising an electrode active material, an optional additive solution or conductive paste for lubricating the electrode active material, a fibrillable binder, an optional additional conductive material, and, advantageously, at least one type of dry electrolyte powder, the workflow in Figure 5 may proceed to a step of activating the fibrillable binder by one or more activation methods. In the solvent activation step, a solvent may be added to the powder mixture to chemically activate the fibrillable binder, softening it so that it can be stretched longer and thinner without breakage and improving its adhesive strength (step 520). Unlike solvents such as NMP, which are difficult to remove and may involve a long drying process, the solvent added in solvent activation step 520 may have a relatively low boiling point of less than 130°C or less than 100°C (i.e., less than the boiling point of water). Exemplary solvents may include hydrocarbons (e.g., hexane, benzene, toluene), acetic acids (e.g., methyl acetate, ethyl acetate), alcohols (e.g., propanol, methanol, ethanol, isopropyl alcohol, butanol), glycols, acetone, dimethyl carbonate (DMC), diethylcarbamazine (DEC), tetrachloroethylene, and the like. Unlike slurry coating and extrusion processes where the solvent may constitute 60-80% by weight of the resulting wet mixture, the solvent added in step 520 may be less than 20% by weight of the resulting mixture. For example, the ratio of the powder mixture to the added solvent may be approximately 100:10, 100:5, or 100:3.

[0052] Instead of, or in addition to, the solvent activation in step 520, the workflow may include a temperature activation step in which the powder mixture is heated to 70°C or above, preferably 100°C or above, to thermally activate the fibrillable binder (step 530). Similar to the solvent activation step 520, the temperature activation step 530 may soften the fibrillable binder, allowing it to be stretched longer and thinner without breakage, thereby improving its adhesive strength. In the temperature activation step 530, the temperature at which the powder mixture is heated may be below the glass transition temperature of the binder (e.g., 114.85°C for PTFE), so that the softening of the binder may occur before it reaches its glass temperature. Alternatively, the mixture may be heated to a temperature equal to or above the glass temperature of the binder. When both the solvent activation step 520 and the temperature activation step 530 are used, the two steps may proceed in either order.

[0053] With the fibrillable binder chemically and / or thermally activated by either or both of steps 520 and 530, the workflow in Figure 5 may proceed to step 540, which involves fibrillating the binder in the powder mixture by exposing it to shear force. For example, the powder mixture may be blended in a standard kitchen blender or an industrial blender. Sufficient shear force to deform (e.g., stretch) the fibrillable binder to produce a more viscous and pliable mixture can be achieved by blending the powder mixture in a blender at approximately 10,000 RPM for 1 to 10 minutes (e.g., 5 minutes), or by a subsequent kneading process using a commercially available dough mixer or an industrial-sized mortar and pestle. Preferably, a high-shear mixer such as a high-shear granulator (e.g., a jet mill) may be used. If the solvent is added in the solvent activation step 520 to chemically activate the binder, the solvent may optionally be injected into the powder mixture while the powder mixture is subjected to shear force in step 540. Thus, steps 520 and 540 may be performed in a single step.

[0054] After the mixture is subjected to shear force, the workflow in Figure 5 may proceed to step 550, in which the mixture is pressed to produce self-supporting films that function as electrode films 110, 210, and 230. This can be done, for example, at a temperature of 150°C and a roll gap of 20 μm, using, for example, a roller press or a calender. The resulting self-supporting electrode films 110, 210, and 230 may comprise at least one type of electrode active material, at least one type of fibrillable binder, and at least one type of dry electrolyte powder in an amount of 5 to 30 wt% of the self-supporting electrode film. If the electrode films 110, 210, and 230 are to be laminated onto a current collector before coating with dry electrolyte powder 119 to form solid electrolyte layers 120, 220 (steps 320, 430), the workflow in Figure 5 may end in step 560, in which the self-supporting electrode films 110, 210, and 230 are laminated onto the current collector. For example, as explained above, this may be particularly advantageous when generating electrode blocks 100 for a multilayer battery according to the workflow of Figure 3 (i.e., Figure 5 is a sub-workflow of step 310). If no current collector is used, or if a current collector is added later (as in the case of optional steps 460 and 470 in Figure 4), step 560 may be omitted.

[0055] As described above, the workflow in Figure 5 can be advantageously used to produce the electrode films 110, 210, and 230 shown in Figures 1 and 2, which can then be assembled into an electrode block 100 of a multilayer solid-state battery according to the workflow in Figure 3, or into a single-layer solid-state battery 200 according to the workflow in Figure 4. For this purpose, the powder mixture prepared in step 510 of Figure 5 preferably contains at least some dry electrolyte powder as described above, which can make the activated dry process described herein unparalleled suitable for the manufacture of solid-state batteries. By using the workflow in Figure 5 and a combination thereof in Figure 3 or Figure 4, the electrode block 100 or solid-state battery 200 can be manufactured entirely by a dry method from start to finish, thereby completely avoiding the long drying time and reduced battery performance associated with conventional wet methods, resulting in a more practical and efficient solid-state battery manufacturing process.

[0056] Figure 6 shows a workflow for manufacturing an electrolyte membrane. The workflow in Figure 6 may be part of an alternative method for manufacturing a dry solid-state battery. Unlike the solid electrolyte layers 120, 220 described with respect to Figures 1-4, which are formed from dry electrolyte powder 119 directly coated onto electrode films 110, 210, the solid electrolyte layer produced in Figure 6 is in the form of a self-supporting membrane that can then be laminated onto the electrode films. In this regard, it should be noted that the electrode films that receive the electrolyte membrane in Figure 6 can still be produced according to the dry method of Figure 5, thus resulting in another entirely dry process for producing a solid-state battery.

[0057] The workflow in Figure 6 can be considered similar to a dry method for producing an electrode film (such as the exemplary method in Figure 5), the main difference being that the powder mixture contains components for producing a solid electrolyte rather than a cathode or anode. In particular, the workflow in Figure 6 may begin with a step (step 610) of preparing a powder mixture for the electrolyte film. In this case, the dry electrolyte powder (rather than the electrode active material) may constitute the majority of the powder mixture by weight, for example, 80% or more by weight of the powder mixture, for example, 80-97% or 80-99% by weight, preferably 95-99% by weight. An example of the dry electrolyte powder may include any of the materials listed above with respect to the dry electrode powder 119. To form an electrolyte membrane by a dry process (and thus avoid the long drying time associated with conventional wet processes), the powder mixture may further include at least one type of fibrillable binder, such as PTFE, PVP, PVDF, PEO, or CMC, including a composite binder as described in U.S. Patent Application No. 17 / 097,200, entitled "Dry Electrode Manufacture with Composite Binder," which is incorporated by reference above. The use of one or more fibrillable binders that can be further chemically or thermally activated to increase their flexibility, as described above, may enable the powder mixture to be pressed into a self-supporting membrane without damage and without excessive use of solvents such as NMP.

[0058] As in the case of powder mixtures for electrode films 110, 210, and 230, powder mixtures containing dry electrolyte powder are intended to be lubricated by mixing in a polymer-containing additive solution before adding the binder. For example, the powder mixture may include an additive solution containing a polymer additive and a liquid carrier in addition to the dry electrolyte powder (and the fibrillable binder subsequently added). The additive solution may be less than 5% by weight of the powder mixture so that the powder mixture may remain a dry powder despite the relatively small amount of liquid added. For example, the final powder mixture containing dry electrolyte powder, fibrillable binder, and additive solution may have a total solid content of more than 95% by weight. The polymer additive may be the same as those described above. It should be noted that the conductive pastes described above are generally not used when preparing powder mixtures for electrolyte films because their conductivity is typically undesirable in solid electrolytes.

[0059] With a powder mixture comprising dry electrolyte powder, an optional additive solution for lubricating the dry electrolyte powder, and a fibrillable binder prepared, the workflow in Figure 6 may proceed to a step of activating the fibrillable binder by one or more activation methods. That is, the workflow in Figure 6 may include the same solvent activation step 620 as the solvent activation step 520 in Figure 5 and / or the same temperature activation step 630 as the temperature activation step 530 in Figure 5. In this way, the fibrillable binder may be activated chemically and / or thermally, as a result of which it softens and can be stretched longer and thinner without breakage, thus improving its adhesive strength. If both the solvent activation step 620 and the temperature activation step 630 are used, the two steps may proceed in either order. The workflow in Figure 6 may proceed to a step (step 640) of fibrillating the binder in the powder mixture by exposing the powder mixture to shear force, which may be the same as step 540 in Figure 5. If the solvent is added in solvent activation step 620 to chemically activate the binder, the solvent may optionally be injected into the powder mixture while the powder mixture is subjected to shear force in step 640. Thus, steps 620 and 640 may be performed in a single step.

[0060] After the mixture is subjected to shear force, the workflow in Figure 6 may end in step 650, in which the mixture is pressed to produce a self-supporting membrane, which can be performed, for example, in the same manner as step 550 in Figure 5. The resulting self-supporting electrolyte membrane may comprise at least one type of fibrillable binder and at least one type of dry electrolyte powder that constitutes the majority of the self-supporting electrolyte membrane by weight ratio, and which may be in an amount of, for example, 80% or more of the self-supporting electrolyte membrane, for example, 80-97% or 80-99% by weight, preferably 95-99% by weight. Such a self-supporting electrolyte membrane can then be laminated onto an electrode membrane (either a cathode or anode) to produce a solid-state battery or an intermediate product thereof (e.g., an electrode block for a multilayer solid-state battery). Similar to the workflows in Figures 3 and 4, the workflow in Figure 6 may be used in combination with the workflow in Figure 5 to produce a solid electrode block or solid-state battery entirely by a dry method from start to finish. In this way, the long drying time and degradation of battery performance associated with conventional wet methods can be completely avoided, resulting in a more practical and efficient solid-state battery manufacturing process.

[0061] The above description is provided as an example and is not limiting. In consideration of the above disclosure, those skilled in the art can devise variations that fall within the spirit and scope of the invention disclosed herein. Furthermore, the various features of the embodiments disclosed herein can be used individually or in various combinations with each other and are not intended to be limited to any specific combination described herein. Thus, the scope of the claims is not limited by the exemplary embodiments.

Claims

1. A method for manufacturing an electrode block for a solid-state battery, the method being: A step of providing an electrode film having a current collector on a first surface of the electrode film; A step of coating a layer of dry electrolyte powder onto the second surface of the electrode film opposite to the first surface; and The step of pressing the dry electrolyte powder coated on the electrode film to generate a solid electrolyte layer on the electrode film. A method that includes [a certain feature].

2. The step of providing the electrode film having the current collector is: A step of preparing a powder mixture comprising at least one type of electrode active material and at least one type of fibrillable binder; A step of fibrillating the at least one type of fibrillable binder in the powder mixture by exposing the powder mixture to a shear force; The step of pressing the aforementioned powder mixture to form a self-supporting film; and Steps to stack the self-supporting film on the current collector. The method according to claim 1, comprising:

3. The method according to claim 2, wherein the powder mixture further comprises at least one type of dry electrolyte powder.

4. A method for manufacturing a solid battery, wherein the method is: A step of providing a first electrode film having a first surface and a second surface opposite to the first surface; A step of providing a second electrode film having a first surface and a second surface opposite to the first surface; A step of coating the second surface of the first electrode film with a layer of dry electrolyte powder; The step of placing the second surface of the second electrode film on the layer of dry electrolyte powder; and A step of producing a solid battery comprising the first electrode film, on which the layer of dried electrolyte powder is coated, together with the second electrode film by pressing the first electrode film together with the second electrode film. A method that includes [a certain feature].

5. Either or both of the steps of providing the first electrode film and providing the second electrode film are: A step of preparing a powder mixture comprising at least one type of electrode active material and at least one type of fibrillable binder; A step of fibrillating the powder mixture by exposing it to a shear force to the at least one type of fibrillable binder in the powder mixture; and The step of pressing the aforementioned powder mixture to form a self-supporting film. The method according to claim 4, having the following characteristics.

6. The method according to claim 5, wherein the powder mixture further comprises at least one type of dry electrolyte powder.

7. The step of laminating the first electrode film onto the first current collector, with the first current collector on the first surface of the first electrode film; and The step of laminating the second electrode film onto the second current collector, with the second current collector on the first surface of the second electrode film. The method according to any one of claims 4 to 6, further comprising:

8. The method according to claim 7, wherein the steps of laminating the first electrode film and laminating the second electrode film are performed before the coating step.

9. The method according to claim 7, wherein the step of laminating the first electrode film and the step of laminating the second electrode film are performed after the step of pressing.

10. A method for manufacturing an electrode film for a solid-state battery, wherein the method is: A step of preparing a powder mixture comprising at least one type of electrode active material, at least one type of fibrillable binder, and at least one type of dry electrolyte powder, wherein the at least one type of dry electrolyte powder is 5 to 30% by weight of the powder mixture; A step of fibrillating the at least one type of fibrillable binder in the powder mixture by exposing the powder mixture to a shear force; and The step of pressing the aforementioned powder mixture to form a self-supporting film. A method that includes [a certain feature].

11. The method according to claim 10, further comprising the step of adding a solvent to the powder mixture to activate the at least one type of fibrillable binder before the fibrillation step.

12. The method according to claim 10, further comprising the step of heating the powder mixture to 70°C or higher to activate the at least one type of fibrillating binder, prior to the fibrillation step.

13. The method according to any one of claims 10 to 12, wherein the powder mixture further comprises an additive solution having a polymer additive and a liquid carrier, and the additive solution is less than 5% by weight of the powder mixture.

14. The method according to any one of claims 10 to 12, wherein the powder mixture further comprises a conductive paste having a polymer additive, a liquid carrier, and a conductive material, the conductive paste being less than 5% by weight of the powder mixture.

15. It is a self-supporting electrode film: At least one type of electrode active material; At least one type of fibrillable binder; and At least one type of dry electrolyte powder in an amount of 5 to 30% by weight of the self-supporting electrode film A self-supporting electrode film comprising the above features.

16. A method for manufacturing an electrolyte membrane for a solid-state battery, wherein the method is: A step of preparing a powder mixture comprising at least one type of fibrillable binder and at least one type of dry electrolyte powder, wherein the at least one type of dry electrolyte powder constitutes the majority of the powder mixture; A step of fibrillating the at least one type of fibrillable binder in the powder mixture by exposing the powder mixture to a shear force; and The step of pressing the aforementioned powder mixture to form a self-supporting electrolyte membrane. A method that includes [a certain feature].

17. The method according to claim 16, wherein the at least one type of dry electrolyte powder is in an amount of 80 to 97% by weight of the powder mixture.

18. The method according to claim 16, wherein the at least one type of dry electrolyte powder is in an amount of 80% by weight or more of the powder mixture.

19. The method according to claim 18, wherein the at least one type of dry electrolyte powder is in an amount of 80 to 99% by weight of the powder mixture.

20. The method according to claim 19, wherein the at least one type of dry electrolyte powder is in an amount of 95 to 99% by weight of the powder mixture.

21. The method according to claim 16, further comprising the step of adding a solvent to the powder mixture to activate the at least one type of fibrillable binder before the fibrillation step.

22. The method according to claim 16, further comprising the step of heating the powder mixture to 70°C or higher to activate the at least one type of fibrillating binder, prior to the fibrillation step.

23. The method according to claim 16, wherein the powder mixture further comprises an additive solution having a polymer additive and a liquid carrier, and the additive solution is less than 5% by weight of the powder mixture.

24. A method for manufacturing an electrode block for a solid-state battery, the method being: The method according to any one of claims 16 to 23; A step of providing an electrode film having a current collector on a first surface of the electrode film; and The step of stacking the self-supporting electrolyte membrane on the second surface of the electrode membrane opposite to the first surface. A method that includes [a certain feature].

25. The step of providing the electrode film having the current collector is: A step of preparing a powder mixture comprising at least one type of electrode active material and at least one type of fibrillable binder; A step of fibrillating the at least one type of fibrillable binder in the powder mixture by exposing the powder mixture to a shear force; The step of pressing the aforementioned powder mixture to form a self-supporting film; and Steps to stack the self-supporting film on the current collector. The method according to claim 24, having the following characteristics.

26. The method according to claim 25, wherein the powder mixture further comprises at least one type of dry electrolyte powder.

27. A method for manufacturing an electrode block for a solid-state battery, the method being: The method according to any one of claims 16 to 23; Steps include providing an electrode film; and Steps to stack the self-supporting electrolyte membrane on the electrode membrane. A method that includes [a certain feature].

28. The step of providing the electrode film is: A step of preparing a powder mixture comprising at least one type of electrode active material and at least one type of fibrillable binder; A step of fibrillating the at least one type of fibrillable binder in the powder mixture by exposing the powder mixture to a shear force; and The step of pressing the aforementioned powder mixture to form a self-supporting film. The method according to claim 27, having the following characteristics.

29. The method according to claim 28, wherein the powder mixture further comprises at least one type of dry electrolyte powder.

30. It is a self-supporting electrolyte membrane: At least one type of fibrillable binder; and At least one type of dry electrolyte powder in an amount of 80 to 97% by weight of the self-supporting electrolyte membrane A self-supporting electrolyte membrane equipped with the following features.

31. A self-supporting electrolyte membrane At least one type of fibrillable binder; and At least one type of dry electrolyte powder, the at least one type of dry electrolyte powder constitutes the majority of the self-supporting electrolyte membrane by weight. A self-supporting electrolyte membrane equipped with the following features.

32. The self-supporting electrolyte membrane according to claim 31, wherein the amount of the at least one type of dry electrolyte powder is 80% by weight or more of the self-supporting electrolyte membrane.

33. The self-supporting electrolyte membrane according to claim 32, wherein the amount of the at least one type of dry electrolyte powder is 80 to 99% by weight of the self-supporting electrolyte membrane.

34. The self-supporting electrolyte membrane according to claim 33, wherein the amount of the at least one type of dry electrolyte powder is 95 to 99% by weight of the self-supporting electrolyte membrane.

35. A method for manufacturing an electrode block for a solid-state battery, the method being: A step of providing a self-supporting electrolyte membrane according to any one of claims 31 to 34; and Step of laminating the self-supporting electrolyte membrane onto the electrode membrane. A method that includes [a certain feature].

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