Thermoplastic forming method for industrial manufacturing of all-solid-state battery electrodes

Abstract

Described herein is a method for manufacturing all-solid-state battery electrodes. In embodiments, the method includes mixing one or more active materials, one or more electron conductive materials, and one or more solid electrolytes, wherein at least one of the active materials, the electron conductive materials, and the solid electrolytes is a glassy inorganic solid. In embodiments, the method includes heating the mixture to ensure wetting of the active materials, the electron conductive materials, and the solid electrolytes that are not the glassy inorganic solid. In embodiments, the method includes rolling and pressing the mixture.

Description

THERMOPLASTIC FORMING METHOD FOR INDUSTRIAL MANUFACTURING OF ALLSOLID-STATE BATTERY ELECTRODESCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit under 35 U.S.C. §119 of U.S. Provisional Patent Application No. 63 / 671 ,944 filed on July 16, 2024, which is hereby incorporated by reference herein in its entirety.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

[0002] This invention was made with government support under HR0011-22-C- 0097 awarded by the Defense Advanced Research Projects Agency. The government has certain rights in the invention.BACKGROUND

[0003] All-solid-state batteries (referred to herein as ASSB) without any liquid ingredients have garnered significant attention due to their advantages in terms of safety and energy density characteristics, as well as the deployment of advanced battery chemistries. Remarkable progress has been made in enhancing ASSB performance; however, the practical manufacturing of these batteries on an industrial scale remains a significant challenge.

[0004] One of the primary obstacles lies in ensuring optimal physical contact between ASSB’s constituent materials to facilitate global ionic and electronic percolation. This task proves increasingly difficult compared to liquid electrolytebased batteries, as solids lack the fluidity necessary for easy integration. Consequently, additional processing steps are called for in cell assembly. For instance, solid electrolytes require either sintering at high temperatures (greater than or equal to 1000 °C for oxide solid electrolytes, such as LiyLasZ^O^ and its derivatives) or isostatic pressing to reduce (and ideally minimize) porosity. Furthermore, composite cathodes comprising active materials, solid electrolytes, conductive additives (i.e., electron conductors), and polymeric binders call for an extra processing step to ensure adequate physical contact between theseelements, which greatly increases the capital cost, processing time, and energy input for industrial manufacturing of ASSB.SUMMARY OF DISCLOSED EMBODIMENTS

[0005] In one aspect, the present disclosure is directed towards a method for manufacturing all-solid-state battery electrodes. In embodiments, the method includes mixing one or more active materials, one or more electron conductive materials, and one or more solid electrolytes, wherein at least one of the active materials, the electron conductive materials, and the solid electrolytes is a glassy inorganic solid. In embodiments, the method includes heating the mixture to ensure wetting of the active materials, the electron conductive materials, and the solid electrolytes that are not the glassy inorganic solid. In some embodiments, the method includes rolling and pressing the mixture.

[0006] In some embodiments, a densified electrode includes equal to or greater than about 30% by weight of an active material. In some embodiments, the glassy inorganic solid exhibits viscous flow behavior within a temperature range from a glass transition temperature to a crystallization temperature. In some embodiments, the glassy inorganic solid exhibits viscous flow behavior within a temperature range where the active materials, the electron conductive materials, and the solid electrolytes each remain kinetically stable. In some embodiments, the active materials comprise one or more of: LiNio.8Mno.iCoo.i02; LiNixMnyCoi-x-yO2(where x > 0.3, y 0.05); LiCo02; LiNiO2; LiFePCX; LiNio.8Coo i5Alo.o502; LiNixC0yAli-x-yO2(where x > 0.8, y > 0.05); Li2S; Ss; or transition metal sulfides. In some embodiments, the electron conductive materials comprise one or more of: carbonaceous materials; conductive transition metal borides; carbides; nitrides; or sulfides. In some embodiments, the solid electrolytes comprise chalcohalide electrolytes such as Li-M-CI-0 or Li-M-CI-S, wherein M=AI or transition metals.

[0007] In some embodiments, the method comprises mixing one or more polymeric binders with the one or more active materials, one or more electron conductive materials, and one or more solid electrolytes. In some embodiments, the method comprises mixing one or more polymeric binders with the one or more active materials, one or more electron conductive materials, and one or more solidelectrolytes and, the polymeric binders comprise one or more of: thermoplastic solid-state polymer electrolytes; thermoplastic polymeric binders; or polymeric binders capable of fibrillation. In some embodiments, the method comprises mixing one or more polymeric binders with the one or more active materials, one or more electron conductive materials, and one or more solid electrolytes and, the polymeric binders are polymeric binders capable of fibrillation and there are less than or equal to about 5 weight% polymeric binders capable of fibrillation in the mixture. In some embodiments, the method comprises mixing one or more polymeric binders with the one or more active materials, one or more electron conductive materials, and one or more solid electrolytes and, the polymeric binders are polymeric binders capable of fibrillation and there are less than or equal to about 1 weight% polymeric binders capable of fibrillation in the mixture.

[0008] In some embodiments, heating the mixture includes increases a temperature of the mixture above a glass transition temperature of at least one of the glassy inorganic solids. In some embodiments, heating the mixture is performed by a furnace or a hotplate. In some embodiments, rolling and pressing the mixture is performed by a roller press or a calendar.

[0009] According to another aspect of the disclosure, a battery includes: a first current collector; a composite anode disposed on the first current collector; a solid separator disposed on the composite anode; a composite cathode disposed on the solid separator; and a second current collector disposed on the composite cathode. In some embodiments, the composite cathode or the composite anode comprise a thermoplastically formed composite cathode or a thermoplastically formed composite anode comprising one or more active materials, one or more electron conductive materials, and one or more solid electrolytes, where at least one of the active materials, the electron conductive materials, and the solid electrolytes is a glassy inorganic solid.

[0010] In some embodiments, the thermoplastically composite cathode or thermoplastically composite anode is a densified electrode that includes equal to or greater than about 30% by weight of an active material. In some embodiments, the thermoplastically formed composite cathode or a thermoplastically formed composite anode comprise one or more polymeric binders.

[0011] According to another aspect of the disclosure, a battery system includes two or more batteries. In some embodiments, each battery includes: a first current collector; a composite anode disposed on the first current collector; a solid separator disposed on the composite anode; a composite cathode disposed on the solid separator; and a second current collector disposed on the composite cathode. In some embodiments, the batteries share a second current collector. In some embodiments, at least one composite cathode or at least one composite anode comprise a thermoplastically formed composite cathode or a thermoplastically formed composite anode comprising one or more active materials, one or more electron conductive materials, and one or more solid electrolytes, where at least one of the active materials, the electron conductive materials, and the solid electrolytes is a glassy inorganic solid.

[0012] In some embodiments, the thermoplastically composite cathode or thermoplastically composite anode is a densified electrode that includes equal to or greater than about 30% by weight of an active material. In some embodiments, the thermoplastically formed composite cathode or thermoplastically formed composite anode comprise one or more polymeric binders.DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0013] The manner and process of making and using the disclosed embodiments may be appreciated by reference to the figures of the accompanying drawings. It should be appreciated that the components and structures illustrated in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principals of the concepts described herein. Like reference numerals designate corresponding parts throughout the different views. Furthermore, embodiments are illustrated by way of example and not limitation in the figures, in which:

[0014] FIG. 1 is a side cross-sectional view of a battery, including a thermoplastically formed composite cathode;

[0015] FIG. 2 is a top cross-sectional view of a thermoplastically formed composite electrode;

[0016] FIG. 3 is a flowchart of a method of manufacturing all-solid-state battery electrodes;

[0017] FIG. 4 is a depiction of an example heating and wetting process, which is used to manufacture the thermoplastically formed composite electrode; and

[0018] FIG. 5 is a side cross-sectional view of a battery system, including a thermoplastically formed composite electrode.DETAILED DESCRIPTION

[0019] Disclosed herein is an all-solid-state battery (referred to herein as ASSB) electrode and a method for manufacturing said ASSB electrode. FIG. 1 shows an all-solid-state battery 100, including a thermoplastically formed composite electrode, specifically a thermoplastically formed composite cathode 140. A composite anode 120 is disposed on a first current collector 110. A solid separator 130 is disposed on the composite anode 120, the thermoplastically formed composite cathode 140 is disposed on the solid separator 130. A second current collector 150 is disposed on the thermoplastically formed composite cathode 140. The battery 100 including the disclosed electrode exhibits lower interfacial resistance compared to a conventional battery. This is due in part to intimate contact at the active material-electrolyte interface, leading to a decrease in polarization and an increase in utilization of active materials, assuming the components of both batteries are the same.

[0020] In some embodiments, the battery includes a first current collector; a composite anode disposed on the first current collector; a solid separator disposed on the composite anode; a composite cathode disposed on the solid separator; and a second current collector disposed on the composite cathode. The composite cathode or the composite anode can be a thermoplastically formed composite cathode or a thermoplastically formed composite anode comprising one or more active materials, one or more electron conductive materials, and one or more solid electrolytes, where at least one of the active materials, the electron conductive materials, and the solid electrolytes is a glassy inorganic solid. In some embodiments, a densified electrode includes equal to or greater than about 30% by weight of an active material. In some embodiments, the thermoplasticallyformed composite cathode or a thermoplastically formed composite anode further comprise one or more polymeric binders.

[0021] The method for manufacturing the ASSB electrodes (such as the thermoplastically formed composite cathode 140) comprises mixing one or more active materials (referred to herein as AM), one or more ionic conductors, and one or more electronic conductors, at least one of which is a glassy inorganic solid. The resulting mixture is then heated to ensure wetting of other constituent materials. Finally, the mixture is rolled and pressed. Accordingly, the densified solid electrode includes equal to or greater than about 30% (+ / - 3%) by weight of an active material.

[0022] The active materials can store and release Li / Na / H, etc. The active materials include one or more of LiNi0.8Mn0.1Co0.1O2, LiNixMnyCoi-x-y02(where x > 0.3, y > 0.05), LiCo02, LiNiO2, LiFePO4, LiNi0.8Co0.15AI0.05O2, LiNixC0 Ali-x-yO2(where x > 0.8, y > 0.05), Li2S , Ss, and transition metal sulfides. For example, the active materials may include LiNi0.8Mn0.1Co0.1O2, LiCoO2, LiNiO2, LiFeP04, LiNi0.8Co0.15AI0.05O2, Li2S, Ss, and transition metal sulfides. Other active materials, such as Li-Ni-Co-Mn-0 systems with varying Mn:Ni:Co ratios or Li-AI-CI-0 and Li- AI-CI-S systems may be included. Examples of electrochemically active components include LiNi MnyC0i- -yO2(where x > 0.3, y > 0.05), LiCoO2, Li N iO2, LiFeP04, LiNixC0yAli-x-yO2(where x > 0.8, y > 0.05), Li2S, Ss, and transition metal sulfides. In some embodiments, the densified solid electrode includes equal to or greater than about 20% (+ / - 3%), about 25% (+ / - 3%), about 30% (+ / - 3%), about 35% (+ / - 3%), about 40% (+ / - 3%), or about 45% (+ / - 3%) by weight of an active material. In some embodiments, the densified solid electrode includes equal to or greater than about 55% (+ / - 3%), about 60% (+ / - 3%), about 65% (+ / - 3%), about 70% (+ / - 3%), about 75% (+ / - 3%), about 80% (+ / - 3%), or about 85% (+ / - 3%) by weight of an active material.

[0023] Ionic conductors (which may be referred to herein as ion conductors) refer to a solid electrolyte (referred to herein as SE). The SE includes chalcohalide electrolytes, such as Li-M-CI-0 and Li-M-CI-S, where M=AI or transition metals, like Ti, Zr, Fe, etc. (the stoichiometry may vary). The Li-A-CI-E includes LixACIx+y-2ZEZ, wherein A= Al, Ti, Zr, or Fe; E= O or S; 0<x<10, y is the valence of A, and 0<z<3. In some embodiments, the SE may be LiAIChsOo.zs or U2AI2CI6S.

[0024] The electronic conductors (which may be referred to herein as electron conductors) may include electron / electronic conductive materials, including one or more carbonaceous materials, such as carbon nanotubes, carbon fibers, and Super P, or electronically conductive transition metal borides, carbides, nitrides, sulfides, such as TiS2 and MoeSs. The electron conductive materials include one or more carbonaceous materials or conductive transition metal borides, carbides, nitrides, sulfides.

[0025] At least one of the active materials, ionic conductors, and electronic conductors (the active materials, ionic conductors, and electronic conductors may be referred to herein as components) is a glassy inorganic solid. In some embodiments, two of the active materials, ionic conductors, and electronic conductors are glassy inorganic solids. The disclosed battery electrode utilizes at least one glassy inorganic solid among the active materials, ionic conductors, and electronic conductors (i.e., materials offering electrochemical capacity and / or ionic and / or electronic percolation) that exhibits viscous flow at temperatures where all the constituent materials remain kinetically stable.

[0026] In some embodiments, at least one of the active materials, one or more ionic conductors, and one or more electronic conductors is a glassy inorganic solid that exhibits viscous flow behavior within a temperature range from the glass transition temperature to the crystallization temperature of the glassy inorganic solid. In some embodiments, at least one of the glassy inorganic solids exhibits viscous flow behavior within a temperature range where all the constituent materials of the battery electrode remain kinetically stable.

[0027] Some of the components (i.e., the active materials, ion conductors, and electron conductors) may dissolve into the glassy material during thermoplastic forming, which could lead to changes in the flowability or ionic conductivity of the glassy material. Accordingly, the chemical compatibility among components should be considered. The glassy inorganic solid may dissolve other components, such as the active materials. For instance, IJ2S can dissolve into I^AhCleS during thermoplastic forming. Accordingly, solubility during the process andelectrochemical activity afterward is considered when manufacturing the ASSB electrodes.

[0028] Other constituting materials refers to electrode components other than the glassy inorganic solid, which are included in the electrode. For instance, consider a composite cathode consisting of an active material, an electronic conductor, and a solid electrolyte: if the solid electrolyte is the glassy inorganic solid, then the other constituting materials would be the active material and the electronic conductor. Other constituting materials may include materials in addition to the active materials, ionic conductors, and electronic conductors, that are used for the battery electrodes. These constituting materials encompass electrochemically active components and substances that ensure global ionic and electronic percolation within the electrode structure. Examples of substances that ensure global ionic and electronic percolation within the electrode structure are glassy solid electrolytes, such as Li-AI-CI-0 or Li-AI-CI-S, and carbon nanotubes. For example, if the solid electrolyte used is a glassy inorganic solid, the other constituting materials include the active materials and conductive additives. For example, 70 weight (wt)% of cathode active materials (e.g., LiNio.8Mno.1Coo.1O2), 20 wt% of glassy solid electrolyte, 5 wt% of carbon nanotubes (CNT), and 5 wt% of polytetrafluoroethylene (PTFE) can be mixed, using a planetary mixer, to form the electrode.

[0029] Additionally, one or more polymeric binders may be included in the electrode. In some embodiments, the method includes mixing one or more polymeric binders with the one or more active materials, one or more electron conductive materials, and one or more solid electrolytes. In some embodiments, there are no polymeric binders. The polymeric binders may include one or more of thermoplastic solid-state polymer electrolytes, thermoplastic polymeric binders, or polymeric binders capable of fibrillation.

[0030] The polymeric binders may include thermoplastic solid-state polymer electrolytes, for example polyurethane and poly(ethylene oxide). The polymeric binders may include thermoplastic polymeric binders, for example polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polyamides, polyarylates,polyimides, polysulfone polyethersulfone, polyetherimide, polyphenylene sulfide, and polyetherketone.

[0031] The polymeric binders may include polymeric binders capable of fibrillation (which may be referred to herein as fibrillizing polymeric binders). Polymer fibrilliation refers to the process by which polymer materials, often in the form of fibers or films, undergo a splitting or unraveling into finer fibers or fibrils. This can result from mechanical stresses, a chemical reaction, or during processing. Examples of such polymeric binders include polytetrafluoroethylene (PTFE), copolymers of PTFE with other monomers (e.g., ethylene, hexafluoropropylene), etc. In some embodiments, the polymeric binders are polymeric binders capable of fibrillation, wherein there are less than or equal to about 5 weight% (+ / - 2 weight%) polymeric binders capable of fibrillation in the mixture. In some embodiments, the polymeric binders are polymeric binders capable of fibrillation, wherein there are less than or equal to about 1 weight% (+ / - 0.2 weight%) polymeric binders capable of fibrillation in the mixture.

[0032] The addition of such fibrillizing polymeric binders reduces energy density; thus, it is ideally the best to use less. Moreover, polymeric binders are typically insulators, and thus, using more than or equal to about 5 weight% (+ / - 2 weight%) of polymeric binders in the mixture that forms the electrode may increase resistance. Accordingly, in some embodiments, the fibrillizing polymeric binders in the mixture may be less than or equal to about 5 weight% (+ / - 2 weight%). In embodiments, the fibrillizing polymeric binders in the mixture may be less than or equal to about 1 weight% (+ / - 0.2 weigh %). In some embodiments, there may be no fibrillizing polymeric binders in the mixture. The ASSB electrode comprises glassy inorganic solids and components other than glassy inorganic solid.

[0033] There are a number of differences between a conventional electrolyte and the disclosed electrolyte. Specifically, there will be a lack of noticeable particle boundaries in the glassy phase if the electrode is thermoplastically formed, such as the disclosed electrolyte. In comparison, if the electrode is formed using a conventional method, there will likely be visible particle boundaries with some trapped voids at the interfaces even when the glassy phase is used.

[0034] FIG. 2 shows a thermoplastically formed composite electrode 200, which may be similar to or the same as thermoplastically formed composite cathode 140 of FIG. 1. The thermoplastically formed composite electrode 200 one or more includes glassy inorganic solids 204 disposed among components other than glassy inorganic solid 202. The glass inorganic solids 204 may be ion conductors. If the glassy inorganic solid 164 is an ion conductor, then the inorganic solid 202 would refer to the active materials, electron conductors, etc.

[0035] FIG. 3 is a flowchart of a method of manufacturing all-solid-state battery electrodes 300. In block 302, one or more active materials, one or more electron conductive materials, and one or more solid electrolytes are mixed, wherein at least one of the active materials, the electron conductive materials, and the solid electrolytes is a glassy inorganic solid.

[0036] In block 302, the materials are mixed through a dry mixing process. The active materials, ionic conductors, and electronic conductors are mixed through dry mixing. The dry mixing further includes the various constituting materials required for the battery electrodes, meaning it may include those materials other than the active materials, ionic conductors, and electronic conductors. In some embodiments, the dry mixing process may be similar to or the same as a conventional dry mixing process.

[0037] In block 304, the mixture is heated to ensure wetting of the active materials, the electron conductive materials, and the solid electrolytes that are not the glassy inorganic solid. Once mixed, the resulting mixture is heated to a temperature at which the glassy inorganic solids are transferred to a viscous flow state (this process step may be referred to herein as “heating and wetting”). Heating the mixture includes increases a temperature of the mixture above a glass transition temperature of at least one of the glassy inorganic solids. Wetting refers to a phenomenon where a liquid phase or a glassy phase spreads across the surface of a solid phase. During this stage, complete wetting of the other constituting materials by the viscous inorganic solids is obtained. Accordingly, the mixture is heated, resulting in complete wetting.

[0038] In block 236, the mixture is rolled and pressed. Accordingly, the mixture undergoes roll-to-roll processing and a pressing process.

[0039] FIG. 4 is a depiction of an example heating and wetting process, which is used to manufacture a thermoplastically formed composite electrode. The example heating in wetting process shown in FIG. 4 may be similar to or the same as the method of manufacturing all-solid-state battery electrodes 300 of FIG. 3.

[0040] In an initial pre-processing stage 410, a glassy component 412 and other components 414 are separate, other components 414 referring to the active materials, electron conductive materials, and / or binders. Next, the glassy component and other components undergo mixing and pressing in a first process step 416. A resulting composite 420 has incomplete contact between the glassy component 422 and other components 424, as indicated in a circled area 426. The incomplete contact indicates the resulting composite 420 has incomplete wetting.

[0041] The resulting composite undergoes heating and liquid infiltration in a second process step 230. A temperature of 200 °C is used for glassy solid electrolyte, such Li-AI-CI-0 or Li-AI-CI-S. A resulting composite 440 has complete contact between the glassy component 442 and other components 444, as indicated in a circled area 446. The complete contact indicates the resulting composite 440 has complete wetting.

[0042] The disclosed method utilizes thermoplastic forming, incorporating a class of inorganic and viscous SE that exhibit viscous (viscous may be referred to herein as sticky) flowability at elevated temperatures. Elevated temperatures refer to a temperature between the glass transition temperature and the crystallization temperature of the glassy inorganic solid or above the melting temperature of the glassy inorganic solid. The glass transition temperature refers to the range of temperatures over which a glass transition occurs. A glass transition is the gradual and / or reversible transition of an amorphous material, or in amorphous regions within semicrystalline materials, from a hard and relatively brittle (e.g., glassy) state into a viscous or rubbery state as the temperature is increased. Glass can refer to an amorphous solid that exhibits a glass transition. Crystallization temperature refers to the temperature at which a material (e.g., a polymer) transitions from a molten state or an amorphous state to a crystalline state during cooling. For example, for Li-AI-CI-O, which has a glass transition temperaturebelow 0°C and a melting temperature of 160°C without clear crystallization peaks in between, a temperature above 0°C could be utilized.

[0043] To determine the viscous flowability, an analysis of the creeping rate under constant load or the loss modulus from dynamic mechanical analysis may be used. At temperatures ranging from the glass transition temperature to the crystallization temperature, a certain class of glassy inorganic solids demonstrate viscous flow behavior. This characteristic allows normally brittle bulk glassy inorganic solids to undergo plastic deformation, making them amenable to being shaped as desired. The advantageous flowability of these materials can also enhance the true contact area between glassy inorganic solids and other neighboring materials.

[0044] The heating occurs within a temperature range where all the constituent materials of the battery electrodes remain kinetically stable. The heating the mixture is performed by a furnace or a hotplate. The heating and wetting promotes physical contact and wetting between the glassy inorganic solids and other materials, improving adhesion within the constituting elements of the mixture. Enhancing true contact area can thereby increase (i.e., improve) adhesion. Improving adhesion can reduce interfacial resistance and thus lower the overpotential during cycling. This leads to a decrease in energy dissipation as heat and an increase in Coulombic efficiency for a given voltage range.

[0045] In embodiments, the heating increases the temperature above the glass transition temperature of one of the glassy inorganic solids and promotes physical contact and wetting between the glassy inorganic solids and other materials, improving adhesion within the constituting elements of the mixture. In embodiments, the heating and wetting may increase the temperature above the glass transition temperature of one of the glassy inorganic solids.

[0046] Additionally, porosity can also be used to roughly estimate the degree of wetting. Conventional heating of a mixture without a glassy phase can induce sintering and / or densification, however a liquid-like flow is not possible with those conventional techniques.

[0047] Once heating and wetting is complete, the mixture is rolled and pressed. The final step of the manufacturing process involves a roll-to-rollprocessing and the pressing process conducted at an elevated temperature. The elevated temperature is between the glass transition temperature and the crystallization temperature or the melting temperature of the glassy inorganic solid if the crystallization temperature is not well-defined. For instance, for Li-AI-CI-O, which has a glass transition temperature below 0°C and a melting temperature of 160°C without clear crystallization peaks in between, rolling may be performed at room temperature. The rolling and pressing the mixture is performed by a roller press or calendar. The two successive processing techniques ensure the formation of thin and dense solid-state battery electrodes.

[0048] The rol l-to-roll processing and the pressing process ensures the formation of dense solid-state battery electrodes. Porosity can be used to estimate how densely packed the electrode is. The resulting electrode is as small as possible (e.g., less than or equal to 1 %, which means greater than or equal to 99% dense electrodes).

[0049] An example of a method for manufacturing the ASSB electrode is as follows: 70 wt% of LiNi0.8Mn0.1Co0.1O2 (NCM811 ), 20 wt% of LiAICI25O0.75 (LACO) electrolyte, 5 wt% of CNT, and 5 wt% of PTFE are mixed for 30 mins using a planetary mixer. The obtained mixture is heated at 200 °C for 5 mins to let the LACO melt and infiltrate all the voids between NCM81 1 particles. Finally, the heated sample is rolled into a thin film (200 urn thickness) and pressed under 300 MPa to be fully densified. Accordingly, a thin and dense NCM811 solid-state cathode is obtained.

[0050] FIG. 5 is a side cross-sectional view of a battery system 500. The battery system 500 includes a first composite anode 520 disposed on a first current collector 510. A first solid separator 530 is disposed on the first composite anode 520. A composite cathode 540 is disposed on the first solid separator 530. A second current collector 550 is disposed on the composite cathode 540. A second composite cathode 560 is disposed on second current collector 550. A second solid separator 570 is disposed on the second composite cathode 560. A second composite anode 580 is disposed on the second solid separator 570. A third current collector 590 is disposed on the second composite anode 580. The disclosed ASSB electrode may be utilized as one or more of a cathode, such asthe composite cathode 540, 560, and / or as an anode, such as composite anode 520, 580, in a battery, such as the battery system 500.

[0051] The battery system 500 including the disclosed electrode exhibits higher energy density compared to a conventional battery. Each of the disclosed batteries achieves a higher specific capacity and output voltage, assuming the components of both batteries are the same.

[0052] In some embodiments, the battery system includes two or more batteries. Each battery in the battery system includes a first current collector; a composite anode disposed on the first current collector; a solid separator disposed on the composite anode; a composite cathode disposed on the solid separator; and a second current collector disposed on the composite cathode. The batteries share a second current collector. At least one composite cathode or at least one composite anode comprise a thermoplastically formed composite cathode or a thermoplastically formed composite anode comprising one or more active materials, one or more electron conductive materials, and one or more solid electrolytes, where at least one of the active materials, the electron conductive materials, and the solid electrolytes is a glassy inorganic solid. A densified electrode includes equal to or greater than about 30% by weight of an active material. The thermoplastically formed composite cathode or a thermoplastically formed composite anode further comprise one or more polymeric binders.

[0053] Two differences between the disclosed method and so-called dry electrode manufacturing include: (a) the as-formed electrode can already function in battery without later injection and infiltration of liquid electrolytes into the said electrode; and (b) the disclosed electrode does not include as many polymeric binders (i.e. , polytetrafluoroethylene (PTFE)) as conventional electrodes, since this class of inorganic SE provides additional binding functionality. A free-standing ASSB electrode can thus be manufactured in a continuous high-throughput manner by thermoplastic forming.

[0054] The disclosed method provides a number of advantages over conventional techniques. Dry battery electrode techniques have provided promising prospects for the battery industry with several advantages over conventional wet coating methods due to non-solvent process that includeenvironmental friendliness, low cost, enhanced compatibility, high production efficiency, and increased electrode performances. In contrast, the disclosed manufacturing method further enhances these advantages by offering several additional benefits over the dry battery electrode techniques, including: reduced polymeric binder usage; and, streamlined processing.

[0055] In relation to the reduced polymeric binder usage, conventional dry battery electrode techniques typically call for greater than 1 .5 wt.% of polymeric binders. Polymeric binders have been employed to increase physical contact between constituting materials and enable roll-to-roll processing. However, binders do not contribute to either capacity or ionic / electronic percolation.

[0056] Unlike conventional dry battery electrode techniques, the disclosed method allows for a reduction in the amount of polymeric binder called for, potentially to zero. Glassy inorganic solids with viscous flow behavior at elevated temperatures can be bifunctional, enabling adhesion between constituting materials as well as contributing to either capacity or ionic / electronic percolation. As a result, the reliance on polymeric binders can be reduced (and ideally minimized) without compromising the structural integrity and performance of the electrodes, improving volumetric and gravimetric capacities.

[0057] For oxide cathodes, the electrode-specific capacity is typically around 180 mAh / g (assuming 215 mAh / g for the active material and a weight fraction of active materials at 85%). The volumetric capacity is about 0.7 Ah / cm3(+ / - 0.1 Ah / cm3). Both gravimetric and volumetric capacities can increase by approximately about 2% (+ / - 0.1 %) and about 3% (+ / - 0.1 %), respectively.

[0058] In relation to the streamlined processing, the disclosed method can eliminate additional processing steps needed to ensure proper physical contact between the constituent materials. In conventional methods, additional measures such as high-pressure application (> 400 MPa) is often necessary. However, through the disclosed thermoplastic forming approach, the viscous flowability of glassy inorganic solids ensures the wetting of the materials, facilitating good physical contact during the electrode manufacturing process. Accordingly, the disclosed battery electrode demonstrates enhanced physical contact betweenelectrochemically active components and substances for electronic and ionic percolation.

[0059] Various embodiments of the concepts, systems, devices, structures and techniques sought to be protected are described herein with reference to the related drawings. Alternative embodiments can be devised without departing from the scope of the concepts, systems, devices, structures and techniques described herein. It is noted that various connections and positional relationships (e.g., over, below, adjacent, etc.) are set forth between elements in the following description and in the drawings. These connections and / or positional relationships, unless specified otherwise, can be direct or indirect, and the described concepts, systems, devices, structures and techniques are not intended to be limiting in this respect. Accordingly, a coupling of entities can refer to either a direct or an indirect coupling, and a positional relationship between entities can be a direct or indirect positional relationship.

[0060] As an example of an indirect positional relationship, references in the present description to forming layer "A" over layer "B" include situations in which one or more intermediate layers (e.g., layer "C") is between layer "A" and layer "B" as long as the relevant characteristics and functionalities of layer "A" and layer "B" are not substantially changed by the intermediate layer(s).The following definitions and abbreviations are to be used for the interpretation of the claims and the specification. As used herein, the terms "comprises," "comprising, "includes," "including," "has," "having," "contains" or "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, a mixture, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but can include other elements not expressly listed or inherent to such composition, mixture, process, method, article, or apparatus.

[0061] Additionally, the term "exemplary" is used herein to mean "serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments or designs. The terms "one or more" and "one or more" are understood to include any integer number greater than or equal to one, i.e. one,two, three, four, etc. The terms "a plurality" are understood to include any integer number greater than or equal to two, i.e. two, three, four, five, etc. The term "connection" can include an indirect "connection" and a direct "connection".

[0062] References in the specification to "one embodiment, "an embodiment," "an example embodiment," etc., indicate that the embodiment described can include a particular feature, structure, or characteristic, but every embodiment can include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0063] For purposes of the description hereinafter, the terms "upper," "lower," "right," "left," "vertical," "horizontal, "top," "bottom," and derivatives thereof shall relate to the described structures and methods, as oriented in the drawing figures. The terms "overlying," "atop," "on top, "positioned on" or "positioned atop" mean that a first element, such as a first structure, is present on a second element, such as a second structure, where intervening elements such as an interface structure can be present between the first element and the second element. The term "direct contact" means that a first element, such as a first structure, and a second element, such as a second structure, are connected without any intermediary conducting, insulating or semiconductor layers at the interface of the two elements. It should be noted that the term "selective to, "such as, for example, "a first element selective to a second element," means that the first element can be etched and the second element can act as an etch stop.

[0064] Use of ordinal terms such as “first,” “second,” “third,” etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements.

[0065] The terms “approximately” and “about” may be used to mean within ±20% of a target value in some embodiments, within ±10% of a target value in some embodiments, within ±5% of a target value in some embodiments, and yet within ±2% of a target value in some embodiments. The terms “approximately” and “about” may include the target value. The term “substantially equal” may be used to refer to values that are within ±20% of one another in some embodiments, within ±10% of one another in some embodiments, within ±5% of one another in some embodiments, and yet within ±2% of one another in some embodiments.

[0066] The term “substantially” may be used to refer to values that are within ±20% of a comparative measure in some embodiments, within ±10% in some embodiments, within ±5% in some embodiments, and yet within ±2% in some embodiments. For example, a first direction that is “substantially” perpendicular to a second direction may refer to a first direction that is within ±20% of making a 90° angle with the second direction in some embodiments, within ±10% of making a 90° angle with the second direction in some embodiments, within ±5% of making a 90° angle with the second direction in some embodiments, and yet within ±2% of making a 90° angle with the second direction in some embodiments.

[0067] It is to be understood that the disclosed subject matter is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The disclosed subject matter is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods, and systems for carrying out the several purposes of the disclosed subject matter. Therefore, the claims should be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the disclosed subject matter.

[0068] Although the disclosed subject matter has been described and illustrated in the foregoing exemplary embodiments, it is understood that the present disclosure has been made only by way of example, and that numerouschanges in the details of implementation of the disclosed subject matter may be made without departing from the spirit and scope of the disclosed subject matter.

Claims

What is claimed is:1 . A method for manufacturing all-solid-state battery electrodes, comprising: mixing one or more active materials, one or more electron conductive materials, and one or more solid electrolytes, wherein at least one of the active materials, the electron conductive materials, and the solid electrolytes is a glassy inorganic solid; heating the mixture to ensure wetting of the active materials, the electron conductive materials, and the solid electrolytes that are not the glassy inorganic solid; and rolling and pressing the mixture.

2. The method of claim 1 , wherein a densified electrode includes equal to or greater than about 30% by weight of an active material.

3. The method of claim 1 , wherein the glassy inorganic solid exhibits viscous flow behavior within a temperature range from a glass transition temperature to a crystallization temperature.

4. The method of claim 1 , wherein the glassy inorganic solid exhibits viscous flow behavior within a temperature range where the active materials, the electron conductive materials, and the solid electrolytes each remain kinetically stable.

5. The method of claim 1 , wherein the active materials comprise one or more of: LiNio.8Mno.iCoo.i02; LiNixMnyCoi-x-y02(where x > 0.3, y> 0.05); LiCoO2; LiNiO2; LiFeP04; LiNio.8Coo i5Alo.o502; LiNixCoyAli-x-y02(where x > 0.8, y > 0.05); U2S; Ss; or transition metal sulfides.

6. The method of claim 1 , wherein the electron conductive materials comprise one or more of: carbonaceous materials; conductive transition metal borides; carbides; nitrides; or sulfides.

7. The method of claim 1 , wherein the solid electrolytes comprise chalcohalide electrolytes such as Li-M-CI-0 or Li-M-CI-S, wherein M=AI or transition metals.

8. The method of claim 1 , further comprising mixing one or more polymeric binders with the one or more active materials, one or more electron conductive materials, and one or more solid electrolytes.

9. The method of claim 8, wherein the polymeric binders comprise one or more of: thermoplastic solid-state polymer electrolytes; thermoplastic polymeric binders; or polymeric binders capable of fibrillation.

10. The method of claim 8, wherein the polymeric binders are polymeric binders capable of fibrillation and there are less than or equal to about 5 weight% polymeric binders capable of fibrillation in the mixture.1 1 . The method of claim 8, wherein the polymeric binders are polymeric binders capable of fibrillation and there are less than or equal to about 1 weight% polymeric binders capable of fibrillation in the mixture.

12. The method of claim 1 , wherein heating the mixture includes increases a temperature of the mixture above a glass transition temperature of at least one of the glassy inorganic solids.

13. The method of claim 1 , wherein heating the mixture is performed by a furnace or a hotplate.

14. The method of claim 1 , wherein rolling and pressing the mixture is performed by a roller press or a calendar.

15. A battery, comprising: a first current collector; a composite anode disposed on the first current collector;a solid separator disposed on the composite anode; a composite cathode disposed on the solid separator; and a second current collector disposed on the composite cathode, wherein the composite cathode or the composite anode comprise a thermoplastically formed composite cathode or a thermoplastically formed composite anode comprising one or more active materials, one or more electron conductive materials, and one or more solid electrolytes, where at least one of the active materials, the electron conductive materials, and the solid electrolytes is a glassy inorganic solid.

16. The battery of claim 15, wherein the thermoplastically composite cathode or thermoplastically composite anode is a densified electrode that includes equal to or greater than about 30% by weight of an active material.

17. The battery of claim 15, wherein the thermoplastically formed composite cathode or thermoplastically formed composite anode further comprise one or more polymeric binders.

18. A battery system, comprising: two or more batteries, each battery including: a first current collector; a composite anode disposed on the first current collector; a solid separator disposed on the composite anode; a composite cathode disposed on the solid separator; and a second current collector disposed on the composite cathode, wherein the batteries share a second current collector, wherein at least one composite cathode or at least one composite anode comprise a thermoplastically formed composite cathode or a thermoplastically formed composite anode comprising one or more active materials, one or more electron conductive materials, and one or more solid electrolytes, where at least one of the active materials, the electron conductive materials, and the solid electrolytes is a glassy inorganic solid.

19. The battery system of claim 18, wherein the thermoplastically composite cathode or thermoplastically composite anode is a densified electrode that includes equal to or greater than about 30% by weight of an active material.

20. The battery system of claim 18, wherein the thermoplastically formed composite cathode or thermoplastically formed composite anode further comprise one or more polymeric binders.

Images