Method for controlling cycle pressure of secondary battery

Abstract

The invention relates to a method for controlling the circulation pressure of a secondary battery. The method comprises the following steps: sequentially stacking and assembling a positive electrode, a diaphragm and a negative electrode into the secondary battery; activating the secondary battery by applying a pressure of 5 MPa or less; and circulating the secondary battery by applying a pressure of 5 MPa or less.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 546,685, filed October 31, 2023; U.S. Provisional Application No. 63 / 547,809, filed November 8, 2023; U.S. Non-Provisional Application No. 18 / 930,823, filed October 29, 2024; U.S. Non-Provisional Application No. 18 / 930,862, filed October 29, 2024; and Korean Patent Application No. 10-2024-0151089, filed October 30, 2024, the entire contents of which are expressly incorporated herein by reference. Technical Field

[0003] This invention relates to a method for controlling the cycle pressure of a secondary battery. Background Technology

[0004] With technological advancements and a surge in demand for portable power sources for portable devices, rechargeable secondary batteries have become widely used as the primary energy source for a variety of portable devices. Furthermore, secondary batteries have generated considerable interest as a power source for electric vehicles, hybrid vehicles, plug-in hybrid vehicles, urban air mobility (UAM) vehicles, and similar innovative products designed to mitigate air pollution and other climate impacts from existing gasoline or diesel vehicles.

[0005] Secondary batteries are typically classified according to their shape (e.g., form factor). Exemplary battery form factor classifications include coin-shaped batteries, cylindrical batteries, prismatic batteries, pouch batteries, and so on. Notably, among these form factors, pouch batteries are characterized by their construction: a metal layer (foil) is combined with an outer pouch made of a multilayer film comprising synthetic resin layers coated on the upper and lower surfaces of the metal layer. This unique design allows pouch batteries to be significantly lighter than cylindrical or prismatic batteries, and their flexible shape enables them to be produced in a variety of forms, making them particularly attractive for a wide range of applications.

[0006] The manufacture of pouch cells typically involves a cell activation process following battery assembly. This activation process usually requires pressurizing the cell using a fixing device (e.g., a clamp), followed by charging and discharging the cell by applying current up to a predetermined voltage. The necessity of this activation process lies in its role to deactivate the positive electrode active material during the initial cycling phase and promote the formation of a stable surface film (often called a solid electrolyte interface (SEI) layer) on the negative electrode.

[0007] For batteries using negative electrodes with large volume fluctuations (such as silicon and lithium metal), precise and uniform pressure needs to be applied during the cell pressurization stage of the activation process to achieve excellent performance. Uneven pressure applied to the cell during the activation process not only reduces battery performance but also adversely affects battery life.

[0008] Therefore, there is a need for a battery cell pressurization device that can continuously apply uniform pressure to optimize battery performance.

[0009] [Background Technical Documents]

[0010] Korean Patent Application Publication No. 10-2019-0072289 was published on June 25, 2019. Summary of the Invention

[0011] Technical issues

[0012] One object of the present invention is to provide a method for controlling the cycle pressure of a secondary battery.

[0013] Technical solution

[0014] On one hand, this disclosure provides a battery cell pressurization device, which includes: A housing, wherein the battery cells are disposed inside the housing; and The fluid fills the inside of the casing and pressurizes the battery cell. In this process, during at least one of the charging and discharging phases of the battery cell, the fluid isotropically pressurizes the battery cell.

[0015] In one example of this disclosure, the secondary battery may be a lithium secondary battery.

[0016] In one example of this disclosure, the membrane may include a solid electrolyte (SSE).

[0017] In one example of this disclosure, the secondary battery can be encapsulated in a pouch cell.

[0018] In one example of this disclosure, the secondary battery may be an all-solid-state battery (AASB).

[0019] In one example of this disclosure, the positive electrode may include LiNi. 0.8 Co 0.1 Mn 0.1 O2 (NCM811).

[0020] In one example of this disclosure, the diaphragm may include Li6PS5Cl.

[0021] In one example of this disclosure, the negative electrode may include Si.

[0022] In one example of this disclosure, the method may further include applying a manufacturing pressure of about 300 MPa to about 500 MPa to the assembled battery.

[0023] In one example of this disclosure, the cycle can be performed at room temperature.

[0024] In one example of this disclosure, the loop can run for approximately 30 to 100 iterations.

[0025] On the other hand, this disclosure provides a battery pack including the battery cell pressurization device.

[0026] In one example of this disclosure, activation and cycling of the secondary battery can be performed using an isostatic pouch cell holder (IPCH) configured to apply isostatic pressure to the secondary battery.

[0027] In one example of this disclosure, the IPCH may include at least one of aluminum (Al), stainless steel (SUS), titanium (Ti), nickel (Ni), iron (Fe), and copper (Cu).

[0028] In one example of this disclosure, the IPCH may include one of 304 stainless steel, 7075 Al alloy, or Ti-6Al-4V.

[0029] Beneficial effects

[0030] This disclosure provides a method for controlling the cycle pressure of a secondary battery.

[0031] This disclosure provides a battery cell pressurizing device capable of isotropically pressurizing battery cells, and a battery pack including the same.

[0032] Furthermore, this disclosure may provide a battery cell pressurization device capable of preventing performance and lifespan degradation of battery cells during their charging / discharging, and a battery pack comprising the same. Attached Figure Description

[0033] Figure 1 A perspective view of a battery cell pressurization device, representing one aspect of this disclosure, is shown.

[0034] Figure 2 A graph illustrating the voltage profile of a battery cell after one cycle using a battery cell pressurizing device employing one aspect of this disclosure or a battery cell pressurizing device employing a static pressure clamp.

[0035] Figure 3 A graph illustrating the coulombic efficiency of a battery cell using a battery cell pressurizing device employing one aspect of this disclosure or a battery cell pressurizing device employing a hydrostatic clamp.

[0036] Figure 4 A diagram illustrating the discharge capacity of a battery cell using a battery cell pressurizing device employing one aspect of this disclosure or a battery cell pressurizing device employing a static pressure clamp.

[0037] Figure 5 A perspective view of a battery cell pressurization device, representing another aspect of this disclosure, is shown.

[0038] Figure 6 A graph showing the relationship between the weight and pressure level of the battery cell pressurization device for comparative examples and aspects of this disclosure is provided.

[0039] Figure 7 The force distribution of the isostatic pressure applied by the fluid in the battery cell pressurization device of this disclosure is shown.

[0040] Figure 8 A comparison is shown between the structures of various uniaxial pouch cell holders (UPCH) and the isostatic pouch cell holders (IPCH) of this disclosure.

[0041] Figure 9 An unmodified UPCH and an improved UPCH with springs and rubber pads, representing aspects of this disclosure, are shown.

[0042] Figure 10 An image of the pressure paper of an aspect of this disclosure is shown.

[0043] Figure 11 Details of the pressure distribution of each pressure paper of the ASSPC of this disclosure, the side profile of the cell, the voltage curve, and the reversible discharge capacity are shown.

[0044] Figure 12 Various comparative schematic diagrams of cell stacks of aspects of this disclosure are shown.

[0045] Figure 13 A graph showing the cyclic pressure characteristics of an ASSPC using IPCH is presented for aspects of this disclosure.

[0046] Figure 14 Nyquist plots of pouch cells manufactured at 500 MPa and cycled at 5 MPa, 3 MPa and 2 MPa using IPCH are shown for aspects of this disclosure.

[0047] Figure 15 The diagram shows the EIS results of the ASSPC cycle, the capacity retention and CE of the pouch cell, the average discharge capacity of the pouch cell, and a schematic diagram illustrating the changes in SSE and contact loss between the positive electrode in aspects of this disclosure.

[0048] Figure 16A schematic diagram illustrating the pressurization process of this disclosure is provided.

[0049] Figure 17 Impedance diagram of a pouch cell of an aspect of this disclosure after 100 cycles at 5 MPa is shown.

[0050] Figure 18 A graph showing the discharge capacity of the ASSPC, one aspect of this disclosure, is illustrated after cycling at 1 MPa, repressurizing at 500 MPa, and then measuring again at 5 MPa.

[0051] Figure 19 A schematic diagram and a cross-sectional view of the double-layer pouch cell of the present disclosure are shown, along with a plasma-focused ion beam scanning electron microscope (P-FIB SEM) cross-section, voltage curves of the pouch cell at different cycle numbers, a graph of the capacity retention of the double-layer ASSPC, and a photograph of the double-layer ASSPC in the IPCH powering an incandescent bulb.

[0052] Figure 20 The diagram shows the capacity retention and coulombic efficiency of pouch cells manufactured using various pressures, representing one aspect of this disclosure.

[0053] Figure 21 A diagram showing the P-FIB cross-section of the NCM811 cathode composite calendered under different pressures according to aspects of this disclosure is presented.

[0054] Figure 22 This is a flowchart of a method for using isostatic cells based on aspects of this disclosure.

[0055] Figure 23 A battery pack representing one aspect of this disclosure is shown.

[0056] Figure 24 A schematic diagram of a solid-state battery, one aspect of this disclosure, is shown. Detailed Implementation

[0057] The aspects of this disclosure will be described in detail below with reference to the accompanying drawings. In the drawings, all or part of the configuration may be exaggerated for ease of description.

[0058] Furthermore, those skilled in the art should understand that this disclosure is not limited to the contents described in the drawings or this specification, and that this disclosure may be implemented in various forms without departing from the technical spirit of this disclosure.

[0059] The shapes, dimensions, areas, ratios, angles, quantities, etc., shown in the accompanying drawings to describe various exemplary aspects of this disclosure are given by way of example only. Therefore, this disclosure is not limited to the descriptions in the drawings. Unless otherwise stated, the same reference numerals generally denote the same elements throughout the specification. Furthermore, the term "may" fully encompasses all meanings and scope of the term "may".

[0060] When terms such as “comprising,” “having,” “including,” “containing,” “constituting,” “made of,” or “formed from” are used, one or more additional elements may be added unless more restrictive terms such as “only” are used. The terms and names used in this disclosure are for describing particular aspects only and are not intended to limit the scope of this disclosure. Elements described in the singular are intended to include multiple elements and vice versa, unless the context clearly indicates otherwise.

[0061] In describing the elements of this disclosure, the terms “first,” “second,” “A,” “B,” “(a),” “(b),” etc., may be used. These terms are intended to distinguish the corresponding element from other elements, and are not used to define the nature, basis, order, sequence, or quantity of the meta-elements.

[0062] Features of the various aspects of this disclosure may be connected or combined in whole or in part with each other, and may operate, link, or drive each other in various ways. The various aspects of this disclosure may operate independently of each other, or may operate together in a mutually dependent or related relationship.

[0063] In the activation process, which involves repeatedly charging and discharging the manufactured battery cells to activate them and remove gases, it is sometimes necessary to use a battery cell pressurization device with fixtures to pressurize the cells. Furthermore, after the battery cells are manufactured, it is sometimes necessary to pressurize them during the charging / discharging process before using them.

[0064] For pressurizing battery cells, hydrostatic clamps are mainly used. These clamps pressurize the battery cells by placing shims between them and adjusting the pressure using the battery pack walls (end plates). Hydrostatic clamps are clamps positioned opposite each other relative to the battery cells, applying uniaxial pressure to both sides or opposite sides of the battery cells along one direction (e.g., the vertical direction).

[0065] If conventional battery cell pressurization devices are used to uniaxially pressurize battery cells, a problem arises: during the charging / discharging process of battery cells using materials with significant volume variations, uneven pressure may occur. Uneven pressure during charging / discharging can lead to degradation of the battery's energy density and lifespan.

[0066] Furthermore, if conventional battery cell pressurization devices are used to apply uniaxial pressure to the battery cells, uneven pressurization may cause damage such as cell cracking, performance degradation due to increased resistance in specific areas of the cell, and internal short circuits. This will lead to a deterioration in the performance and lifespan of the battery cells.

[0067] To address these issues or other limitations associated with the prior art, the inventors of this disclosure have completed a battery cell pressurization device capable of applying uniform driving pressure to battery cells using materials with large volume variations, and a battery pack comprising the same.

[0068] Various aspects of this disclosure will now be described in more detail with reference to the accompanying drawings. All components of the various battery cell pressurization devices and battery packs in these various aspects of the disclosure are operatively connected and configured.

[0069] Figure 1 A perspective view of a battery cell pressurization device, representing one aspect of this disclosure, is shown.

[0070] Reference Figure 1 One aspect of the present disclosure is a battery cell pressurization device 1, which includes a housing 10 in which a battery cell 100 is disposed and a fluid 20 filled inside the housing and pressurizing the battery cell 100. In several aspects, the battery cell 100 may be a secondary battery or a solid-state battery (SSB).

[0071] When pressurization is required during the charging / discharging process of the battery cell 100, the battery cell pressurization device 1 of this disclosure can be used. In this aspect of the disclosure, the housing 10 may also be referred to as a container, chamber, or receptacle.

[0072] According to one aspect, the shape of the housing 10 of the battery cell pressurizing device 1 is not particularly limited, and can be, for example, bag-shaped, cylindrical, or prismatic. However, this disclosure is not limited to this. The housing 10 can be pressure-resistant, so as not to deform under the pressure of the fluid 20 located inside the housing 10. For example, the housing 10 can remain undeformed under pressures of tens of MPa or less, such as 20 MPa, 15 MPa, or less than 10 MPa. More specifically, the housing 10 can be pressurized by the fluid 20 at pressures of 1 MPa or more and less than 10 MPa, 2 MPa or more and less than 9 MPa, or 3 MPa or more and less than 8 MPa, and will not deform within the aforementioned pressure ranges. However, this disclosure is not limited to this. Furthermore, the housing 10 can be waterproof or fluid-proof to prevent the fluid 20 from penetrating into the housing 10. From this perspective, metals such as aluminum (Al), stainless steel (SUS), titanium (Ti), nickel (Ni), iron (Fe), copper (Cu), or alloys of two or more of these can be used as the material forming the housing 10, but this is not a limitation. For example, the housing 10 can also be made of composite materials, such as carbon fiber reinforced polymers, glass fibers, or ceramic matrix composites, which can provide a high strength-to-weight ratio and corrosion resistance. Furthermore, advanced alloys such as Inconel, Hastelloy, or titanium alloys can be used for applications requiring excellent strength and chemical resistance. However, this disclosure is not limited to these aspects, and other materials capable of withstanding pressure can be used.

[0073] According to one aspect, when the battery cell 100 is charged / discharged using a charging / discharging device, the fluid 20 can pressurize the battery cell 100. In one aspect of this disclosure, by using the fluid 20 as a means of pressurizing the battery cell 100, the battery cell 100 can be pressurized isotropically and uniformly. That is, the fluid 20 can apply isostatic pressure to the battery cell 100.

[0074] The pressure applied by the fluid 20 to the battery cell 100 can be equal to the pressure applied by the fluid 20 to the casing. The pressure applied by the fluid 20 to the battery cell 100 can be from 1 MPa to 10 MPa. Specifically, the pressure applied by the fluid to the battery cell 100 can be above 1 MPa, above 2 MPa, above 3 MPa, above 4 MPa, above 5 MPa, or below 10 MPa, below 9 MPa, below 8 MPa, below 7 MPa, or below 6 MPa. If the pressure applied by the fluid 20 to the battery cell 100 is less than 1 MPa, the battery cell 100 cannot be sufficiently pressurized, causing the battery cell 100 to expand due to gas or internal pressure within the battery cell 100. Furthermore, if the pressure applied by the fluid 20 to the battery cell 100 exceeds 10 MPa, it may cause physical and chemical damage to the battery cell 100.

[0075] As the fluid 20, a material that will not deform due to the pressure of the fluid itself can be used. In addition, as the fluid 20, a material that will not affect the performance or lifespan of the battery cell 100 can be used.

[0076] Fluid 20 can be a gas or a liquid; specifically, fluid 20 can be a fire-extinguishing or non-flammable or non-volatile gas, oil, or gel. In some aspects, fluid 20 can be a gas, such as air, but this disclosure is not limited thereto. For example, fluid 20 can include an inert gas, such as nitrogen, argon, or helium. Furthermore, fluid 20 can include hydraulic fluids, silicone oils, or fluorinated compounds exhibiting low compressibility and chemical stability, but this disclosure is not limited thereto.

[0077] If the fluid 20 is a gas, effective pressurization can be achieved due to its lighter weight and lower energy density loss compared to a liquid. Table 1 below shows a comparison of the energy density of the internal fluid 20 of the battery cell pressurization device 1 containing battery cells 100 when air and water are used. Here, the battery cell pressurization device 1 includes 10 battery cells and is made of or contains aluminum with a thickness of 0.5 mm.

[0078] [Table 1]

[0079] As shown in Table 1 above, if the battery cell pressurization device 1 contains air as an internal fluid, it can be confirmed that the energy density is high due to the low weight.

[0080] The battery cell pressurization device 1 of one aspect of this disclosure may further include a fluid inlet 30 through which fluid 20 is introduced or discharged.

[0081] For example, when the battery cell 100 is being charged, the volume of the battery cell 100 can increase. At this time, when the pressure inside the casing 10 increases, the fluid 20 can be discharged from the fluid inlet 30.

[0082] For example, when the battery cell 100 discharges, the volume of the battery cell 100 will decrease. At this time, when the pressure inside the casing 10 decreases, fluid 20 can be introduced from the fluid inlet 30 to replenish the fluid 20 inside the casing 10, thereby maintaining the pressure of the fluid 20.

[0083] In some aspects, the fluid inlet 30 may also include valves for controlling the inflow and outflow of fluid 20.

[0084] The battery cell pressurizing device 1 of one aspect of this disclosure may further include a pressurizing member 40 for applying or regulating the internal pressure of the housing 10. The pressurizing member 40 can be used to apply or regulate the driving pressure inside the housing 10 on which the battery cell 100 is disposed using fluid 20. In various aspects of this disclosure, the driving pressure may refer to the pressure applied or regulated inside the housing 10 by the pressurizing member 40.

[0085] For example, the pressurizing member 40 can pressurize the fluid 20 within the housing 10 to apply or regulate the pressure within the housing 10. The pressurizing member 40 can pressurize the fluid 20 or include means for pressurizing the fluid 20, thereby causing an increase or change in pressure within the housing 10. The pressurizing member 40 can be or includes a piston or a hydraulic cylinder, but aspects of this disclosure are not limited thereto. In various aspects of this disclosure, the pressurizing member 40 can change the volume of the fluid 20 already present within the housing 10, thereby changing the pressure within the housing 10. Thus, once a predetermined amount or volume of fluid 20 is filled into the housing 10 using the fluid inlet 30, the pressurizing member 40 can apply, adjust, calibrate, or drive the pressure inside the housing 10 by using the fluid 20.

[0086] A sealing member can be provided on the pressurizing member 40 to prevent the fluid 20 filled inside the housing 10 from being discharged to the outside of the housing 10.

[0087] One aspect of the battery cell pressurization device 1 of this disclosure may further include a pressure measuring member for measuring the pressure within the housing 10. The pressure measuring member can measure pressure changes during at least one process of charging and discharging the battery cell 100 to adjust the driving pressure of the housing 10. In various aspects of this disclosure, the pressure measuring member may include one or more types of pressure gauges. The pressure measuring member may include various types of pressure measuring devices, such as mechanical pressure gauges, digital pressure sensors, piezoresistive sensors, capacitive pressure sensors, strain gauge pressure sensors, fiber optic pressure sensors, or microelectromechanical systems (MEMS) pressure sensors, but aspects of this disclosure are not limited thereto. In some aspects, the pressure measuring member may also include a pressure switch, a differential pressure sensor, or a pressure transmitter to provide accurate and continuous monitoring of the pressure within the housing, but aspects of this disclosure are not limited thereto.

[0088] One aspect of this disclosure, the battery cell pressurizing device 1, may further include wire components for inputting and outputting electrical signals to the battery cell 100. The wire components may be connected to a charging / discharging device to apply current to the battery cell 100 and measure voltage, or they may be connected to a charging / discharging device to apply voltage to the battery cell 100 and measure current. In some aspects of this disclosure, the battery cell pressurizing device 1 may include a wireless charging mechanism in place of the physical wire components. This wireless charging system may utilize electromagnetic induction or resonant inductive coupling to transfer energy (e.g., apply current or voltage) to the battery cell 100 without direct electrical connection. The wireless charging mechanism may include, for example, a transmitting coil located outside the housing 10 and a receiving coil connected to the battery cell 100 inside the housing 10, thereby allowing charging and discharging operations while maintaining the sealed integrity of the housing 10, but aspects of this disclosure are not limited thereto.

[0089] The housing 10 may also include a hole through which wires connected to the battery cell 100 for inputting and outputting electrical signals to the battery cell 100 pass. There may be multiple holes through which multiple wires connected to the positive and negative leads pass.

[0090] A sealing element can be provided around the orifice to prevent the fluid 20 filling the housing 10 from leaking to the outside of the housing 10. Some possible sealing elements may include: O-rings made of materials such as silicone, nitrile rubber, or fluoroelastomers; gaskets made of compressed fiber materials, graphite, or PTFE; mechanical seals with spring-loaded surfaces; packing seals made of braided fibers or PTFE; lip seals or radial shaft seals; compression fittings with collars; hermetic glass-metal seals; epoxy or silicone sealants; bellows seals made of metal or elastomers; packing box seals with adjustable compression; diaphragm seals made of flexible materials; labyrinth seals for non-contact sealing; magnetohydrodynamic seals for rotating shafts; pressurizable pneumatic seals; or brush seals made of fine metal or polymer fibers. The selection of the sealing element can depend on factors such as operating pressure, temperature, chemical compatibility with the fluid, and required service life. In some cases, a combination of multiple sealing methods may be used to provide margin and improve reliability, but this disclosure is not limited thereto.

[0091] In one aspect of this disclosure, a charging / discharging device can apply current to a battery cell 100 via a conductive member to charge / discharge the battery cell 100, thereby activating the battery cell 100. The charging / discharging device can perform its function using various processes, such as detecting defects in the open-circuit voltage (OCV) during aging after the battery cell 100 is fully charged; then fully discharging it again to measure the discharge capacity; and then charging it to 50% of its capacity for shipment. For example, the activation process can be performed under conditions of a current from 0.05C to 1C and a voltage from 1.5V to 5.0V, but is not limited thereto. Other processes can also be used, including any known processes. For example, another process could be pulse charging, in which a short-term high current is applied to the battery cell, followed by a rest period. Furthermore, the charging / discharging device can employ a constant current-constant voltage (CC-CV) method, in which a constant current is applied until a certain voltage is reached, and then the voltage is kept constant while the current is reduced.

[0092] The conductive components can apply current to the battery cell 100 by connecting it to a charging / discharging device. The conductive components can be multiple conductive components connected to a positive lead and a negative lead, respectively. Conductive materials can be used without limitation as the material forming the conductive components. For example, the conductive components can be conductive wires. However, this disclosure is not limited to this.

[0093] According to one aspect of this disclosure, the battery cell 100 may be a pouch-type battery cell. The battery cell 100, pressurized by the battery cell pressurizing device 1, may include a positive electrode, a negative electrode, an electrolyte, and a separator. However, this disclosure is not limited thereto. Furthermore, it may also include positive and negative leads respectively connected to the positive and negative electrodes of the battery cell 100.

[0094] The battery cell 100 can be a pouch-type battery cell, in which the positive electrode, negative electrode, electrolyte, and separator are embedded in the pouch, with some leads exposed outside the pouch. The pouch-type battery cell can be manufactured by: placing the separator between the positive and negative electrodes; performing interlayer bonding by applying pressure using cold isostatic pressing (CIP) or hot isostatic pressing (WIP); then connecting the positive and negative leads, and housing and sealing the electrode assembly thus formed in the pouch.

[0095] Meanwhile, at least two of the dimensions of the positive electrode, negative electrode, and separator of the battery cell 100 can be different from each other. For example, the size of the positive electrode can be smaller than the size of the negative electrode and the size of the separator, respectively. Here, the size can refer to at least one of the longitudinal length (L) and the width length (W). However, the aspects of this disclosure are not limited thereto.

[0096] When a liquid electrolyte is used, a separator may be included. If the bag contains a positive electrode, a negative electrode, and a solid electrolyte, the separator may be omitted. In some respects, the solid electrolyte can serve as both the electrolyte and the separator. Therefore, in one aspect of this disclosure, the battery cell pressurization device 1 can be used not only for batteries using solid electrolytes but also for batteries using liquid electrolytes and requiring high pressure during charging / discharging (e.g., silicon anode batteries, lithium metal batteries, etc.). However, the aspects of this disclosure are not limited thereto.

[0097] However, the structure of the battery cell 100 pressurized by the battery cell pressurizing device 1 of one aspect of this disclosure and activated by the battery cell charging / discharging device is not limited to the structure of the battery cell 100 shown in the figures.

[0098] According to a battery cell pressurizing device 1 of one aspect of this disclosure, fluid 20 is injected into the housing 10, which is provided with a housing 10, through a fluid inlet 30, and the injected fluid 20 can uniformly and isotropically pressurize the battery cell 100. In this state, the battery cell 100 can be activated by charging / discharging it in the battery cell pressurizing device 1. Therefore, the battery cell pressurizing device 1 of this disclosure can prevent the performance and lifespan of the battery cell 100 from being degraded due to the application of isostatic pressure during the charging / discharging process of the battery cell 100.

[0099] According to some aspects, this disclosure can provide a battery pack including a battery cell pressurizing device 1. That is, the housing 10 of the battery cell pressurizing device 1 can itself be used as a battery module. Typically, in the activation process, after the battery cell 100 is placed in the battery cell pressurizing device 1 for activation, the activated battery cell 100 can be removed from the battery cell pressurizing device 1, thereby allowing the battery cell 100 to be installed or manufactured into a battery module or battery pack.

[0100] However, according to various aspects of this disclosure, the housing (or pack, container, module, etc.) of the battery cell pressurizing device 1 of this disclosure can itself be used as a battery module or battery pack, and thus, this use can have excellent economic benefits.

[0101] Figure 2 This illustration shows a graph of the voltage profile of a battery cell after one cycle using a battery cell pressurizing device using one aspect of this disclosure or a battery cell pressurizing device using a hydrostatic clamp. Here, the battery cell pressurizing device of one aspect of this disclosure is an apparatus for pressurizing the battery cell by isostatic pressure, while the battery cell pressurizing device using a conventional hydrostatic clamp pressurizes the battery cell by uniaxial pressure.

[0102] Reference Figure 2 It can be seen that, for the same specific capacity, the battery cell using the battery cell pressurizing device of one aspect of this disclosure has a higher cell voltage than the battery cell using the battery cell pressurizing device using a static pressure clamp. It has been confirmed that because the battery cell using the static pressure clamp has a higher resistance than the battery cell using the battery cell pressurizing device of this disclosure, it has a larger battery cell overvoltage. Therefore, the battery cell isotropically pressurized using the battery cell pressurizing device of this disclosure has a higher cell voltage.

[0103] Figure 3 A graph illustrating the coulombic efficiency of a battery cell pressurizing device using aspects of this disclosure and a battery cell pressurizing device using a hydrostatic clamp is provided.

[0104] Figure 4 The diagram illustrates the discharge capacity of a battery cell using a battery cell pressurizing device according to one aspect of this disclosure and the discharge capacity of a battery cell pressurizing device using a static pressure clamp.

[0105] exist Figure 3 and Figure 4 In this document, a battery cell using a battery cell pressurizing device employing one or more aspects of this disclosure is represented as an embodiment, and a battery cell using a battery cell pressurizing device employing a hydrostatic clamp is represented as a comparative example.

[0106] Reference Figure 3 and Figure 4As can be seen, with repeated cycles, although the coulombic efficiency of the battery cell using the cell pressurization device provided in this disclosure is similar to that of the battery cell using the cell pressurization device using a static pressure clamp, the battery cell using the cell pressurization device of this disclosure has a higher lifespan than the battery cell using the cell pressurization device using a static pressure clamp.

[0107] Figure 5 A perspective view of a battery cell pressurization device, representing another aspect of this disclosure, is shown.

[0108] Reference Figure 5 The battery cell pressurization device may include: a container wall 111 (or housing, housing wall, or sidewall) accommodating a space in which a pouch cell 1100 can be placed; one or more container caps 110 to close the container wall 111; one or more container clamps 120 to secure the container caps 110 to the container wall 111; a valve 300 (e.g., a ball valve) to control the inflow and outflow of a medium, thereby providing pressure; and a pressure gauge 410 to measure or determine the pressure within the container wall 111. To measure or determine various aspects of the pouch cell 1100 in the battery cell pressurization device, a wire 510 may be provided to connect to the pouch cell 1100 via a connector 540. An example of a connector may be an alligator clip.

[0109] A fit-through connector 520 can be provided on the battery cell pressurization device to provide a passage to the space in the container wall 100. In various aspects of this disclosure, the fit-through connector 520 may be located in the container cover 110, but this is not mandatory; the fit-through connector 520 may be located on the container wall 111. The position of the valve 300 can also be varied and may be located in the container cover 110, the container wall 111, or integrated with the pressure gauge 410 or the fit-through connector 520. A sealant can be used to ensure a seal through the fit-through connector 520 and the pressure gauge 410, valve 300, or container clamp 120, etc.

[0110] In one aspect of this disclosure, the container wall 111 may be cylindrical, but this is not mandatory, and other shapes may be used. The container wall 111 may have an annular protrusion at its open end, configured to connect to the annular end of the container lid 110. The container lid 110 may include an internal groove located on its inner surface to receive the annular protrusion of the container wall 111 and the annular end of the container lid 110. In one aspect of this disclosure, the diameter of the container wall 111 may be about 10 cm, and the height of the container wall may be about 20 cm, but this aspect of the disclosure is not limited thereto.

[0111] In various aspects of this disclosure, one or more openings may be provided in the battery cell pressurization device. For example, a first opening may be provided for the probe line 510, a second opening may be provided for the pressure gauge 410, and a third opening may be provided for the pressure valve (or air valve) 300. When three openings are provided, the third opening may be located away from the first and second openings. However, the aspects of this disclosure are not limited thereto.

[0112] In various aspects of this disclosure, the battery cell pressurization device may include at least one window to allow a user to observe the interior of the battery cell pressurization device. At least one window may be located at the container wall 111, but this disclosure is not limited thereto. For example, at least one window may also be located at the container lid 110. In various aspects of this disclosure, at least one window may include one of glass, quartz, and beryllium, but this disclosure is not limited thereto, and other transparent materials may be used. When two or more windows are provided, the positions of the two windows may be aligned so that a probe beam can be used to probe the battery cell located at the aligned axis of the two windows. The probe beam may be X-ray or sound wave. However, this disclosure is not limited thereto.

[0113] In various aspects of this disclosure, the components of the battery cell pressurization device may include steel, stainless steel, aluminum, and titanium, or be formed from one of these materials, but other materials with strength to withstand pressure and cyclic pressure may also be used. Furthermore, the battery cell pressurization device may include a heater to heat the fluid or pressure medium when the pressure medium applies isostatic pressure to the solid-state battery in the battery cell pressurization device. In various aspects of this disclosure, the battery cell pressurization device can withstand repeatedly applied pressure of about 1 MPa to 5 MPa from the pressure medium at room temperature. This battery cell pressurization device may be referred to as an isostatic pouch cell holder (IPCH). In various aspects of this disclosure, the IPCH may be... Figure 1 and Figure 5 One or more of the battery cell pressurization devices shown are included, but aspects of this disclosure are not limited thereto.

[0114] Figure 6 A graph showing the relationship between the weight and pressure level of the battery cell pressurization device for comparative examples and aspects of this disclosure is provided.

[0115] refer to Figure 6 Because the battery cell pressurization device uses a fluid as the pressurizing medium, the pressure is applied evenly to all points in all directions. Therefore, deformation of the container wall and the arrangement of the pouch cells do not affect pressure uniformity. Consequently, the battery cell pressurization device can use thinner walls to reduce the module's weight. The figure shows comparative examples using different metal alloys, pressure ratings from 1 MPa to 10 MPa, and the estimated required weight of the battery cell pressurization device. Figure 6In (a), the values ​​for 304 steel are shown. Figure 6 (b) shows the values ​​for the 7075 Al alloy. Figure 6 (c) shows the value of Ti-6Al-4V. However, this disclosure is not limited to this, and other materials may be used.

[0116] Figure 7 The force distribution of the isostatic pressure applied by the fluid in the battery cell pressurization device of this disclosure is shown. Figure 7 In (a), pressure paper that can be vacuum-sealed into a bag is shown, and its pressure distribution after pressure is applied using an IPCH is illustrated. Figure 7 (b) illustrates the uniform pressure distribution applied to the pouch cell 100. This can be explained using Pascal's principle, which states that in a stationary confined fluid, any change in pressure applied at any point will be transmitted unimpeded in all directions of the fluid. Using a fluid, isostatic pressure can be applied.

[0117] All-solid-state batteries (ASSBs) are considered a potential successor in energy storage technology due to their improved safety by replacing the organic liquid electrolyte in conventional lithium-ion batteries with a non-flammable solid electrolyte (SSE). However, ASSBs are more sensitive to cycling pressure, as pressure is crucial for maintaining tight interfacial contact. Most battery research utilizes uniaxial cell supports to apply cycling pressure. Uniaxial cell supports suffer from limitations such as limited ability to accommodate changes in electrode material volume during cycling, uneven pressure distribution, and difficulty in long-term pressure regulation due to material fatigue and mechanical design constraints. In our study, we designed an isostatic pouch cell support (IPCH) to address these issues. By using a fluid as the pressure medium, uniform cycling pressure can be achieved, and precise cycling regulation is possible. To demonstrate the potential of IPCHs, LiNi was fabricated. 0.8 Co 0.1 Mn 0.1 An all-solid-state bag-type battery cell (ASSPC) consisting of O2 (NCM811) | Li6PS5Cl (LPSCl) | Si was tested for rate performance and long-term cycling (100 cycles) at pressures ranging from 1 MPa to 5 MPa. Electrochemical performance was found to improve with increasing cycling pressure, with 2 MPa considered the minimum required cycling pressure for the NCM811 | Si system. Finally, a bilayer ASSPC with a theoretical capacity of 100 mAh was cycled using an IPCH, achieving a coulombic efficiency of 76.9% and a discharge efficiency of 173.6 mAh g⁻¹ in the first cycle. -1 (88.1 mAh), discharge capacity after fifty cycles is 150 mAh g. -1IPCH has proven to be a promising candidate for stress studies and potential commercialization within the ASSPC framework.

[0118] All-solid-state batteries (ASSBs) are hailed as one of the next-generation energy storage technologies, and significant efforts have been invested in their development. By using a solid-state electrolyte (SSE) instead of the liquid electrolyte in conventional Li-ion batteries, ASSBs exhibit reduced flammability and leakage issues. Furthermore, high-energy-density anodes (such as pure silicon) have been reported to achieve long cycle lives in ASSBs, but this is challenging in liquid electrolytes due to the significant volume changes of Si, which are affected by the continuous formation of the solid-electrolyte interface (SEI). Despite these advantages, ASSBs still face numerous engineering challenges stemming from the solid-solid contact at the interface. Unlike liquid electrolytes, SSEs do not flow and penetrate into the pores of the electrode. Additionally, volume expansion of the electrode material can lead to interfacial detachment. These factors result in poor interfacial ion transport and degrade the electrochemical performance of the SSE. Therefore, pressure becomes a critical factor in ensuring ASSB performance.

[0119] Figure 8 A comparison of the structures of various uniaxial pouch cell holders (UPCH) and isostatic pouch cell holders (IPCH) is shown. Figure 8 In the figures, (a) shows a UPCH with a plunger cell held in a cell holder, (b) shows a multilayer pouch cell, (c) shows an undecorated UPCH with a simple metal plate, (d) shows a UPCH with a spring and a rubber gasket, and (e) shows an IPCH.

[0120] Research laboratories typically use pellet-sized ASSB for electrochemical testing. For example... Figure 8 As shown in (a), a polymer mold and a pair of metal plungers can be used to contain and apply manufacturing pressure, thereby pelletizing the material. During electrochemical testing, a cell support consisting of bolts, nuts, and plates is required to apply cyclic pressure, while the metal plungers act as current collectors. Since most inorganic SSEs are brittle, the SSE layer thickness is typically around 500 µm to ensure sufficient strength to mechanically support the cell. Because the SSE layer does not store energy, this reduces the energy density of the ASSB.

[0121] Furthermore, due to friction from the mold wall during uniaxial pressing, it is difficult to achieve a uniform density distribution throughout the pellet, which negatively impacts its electrochemical performance. Pouch cells, with their thinner layer thickness, larger electrode area, and elimination of the need for polymer molds, not only exhibit significantly higher energy density but also achieve better density distribution after calendering.

[0122] also, Figure 8(b) describes a multilayer pouch cell. Due to the flexibility of the pouch cell's packaging material, isostatic stress can be applied to further improve density uniformity. Pouch cells can include various types of adhesives, such as polymeric adhesives or all-solid-state adhesives. Some all-solid-state adhesives, those so-called "all-solid-state" adhesives, contain excessive amounts of polymeric adhesives, Li salts, or even solvents to compensate for performance issues arising from not achieving an all-solid-state adhesive, and such partial polymeric adhesives can compromise the safety characteristics of ASSB. Nevertheless, several all-solid-state pouch cells (ASSPCs) using only inorganic SSE and a small amount of adhesive can be used for various multilayer pouch cells (see Table 2).

[0123] Table 2. ASSPC Specifications and Cycling Conditions

[0124] Most pouch cells can have an area capacity exceeding 3 mAh cm⁻¹. -2 This is similar to or higher than many commercial lithium-ion batteries. However, many commercial pouch cells can have a C-rate below 0.1 C and may require higher temperatures to achieve higher C-rates and areal capacities. Since SSEs do not flow like liquid electrolytes and conform to the shape of the electrode materials, pressure must be applied to the ASSB to ensure tight interfacial contact during manufacturing and cycling. Many ASSBs are manufactured at manufacturing pressures typically between 300 MPa and 500 MPa, but cycling pressure is not mentioned. However, cycling pressure is likely a more important metric, as high cycling pressure significantly increases the weight of the cell support and impairs the module's energy density. Since low cycling pressure generally reduces interfacial contact, leading to deteriorated electrochemical performance of the ASSB, providing a cell support capable of delivering uniform cycling pressure is crucial.

[0125] Reference Figure 8 (c) A pouch cell holder comprising bolts, nuts, and a rigid plate can be used to apply uniaxial pressure to the pouch cell. Sometimes a bearing can be installed between the moving plate and the bolts to ensure smooth movement and parallelism. However, when uniaxial pressure is applied, the cyclic pressure of the ASSB changes during cell cycling due to volume changes in the electrode material. For example, Si can experience up to 400% volume expansion, while the coating pressure per mAh cm⁻¹... -2 The thickness of the Li metal anode increases by approximately 5 µm. This negatively impacts their electrochemical performance, especially when using varistor materials such as lithium metal. To address this pressing issue, refer to... Figure 8 (d) The spring can be incorporated into the cell support to accommodate changes in volume during cycling. This design can successfully reduce the temperature of LiNi batteries. 0.8 Co 0.1Mn 0.1 The cycling volume of the O2 (NCM811) | Li cell changes, for example, from 2 MPa to less than 0.5 MPa, and doubles its critical current density. However, this disclosure is not limited to this. Rubber and springs are susceptible to material fatigue, and the applied force decreases over time. Due to the different coefficients of thermal expansion of the pouch cell and the bolts, the cell pressure also changes if the ambient temperature fluctuates. Therefore, a pressure regulation system is needed to ensure the stability of the cell cycling. Unfortunately, precisely regulating the pressure by tightening the bolts is challenging because the motor needs to overcome significant frictional forces under high pressure loads, and additional effort is required to synchronize the torque of all bolts in the single cell support. To address this issue, fluids (including gases and liquids) can be used as the pressurizing medium to apply isostatic cycling pressure. Gases can be used when lightweight, low-cost, or low X-ray absorption is required (e.g., for in-situ cell characterization), while liquids can be used when pressure loads and heat dissipation are needed. Reference Figure 8 (e) Unlike the bolts and nuts of UPHC, the isostatic bag-type cell holder (IPCH) can utilize chambers and gaskets to contain pressurized fluid and ASSPC. However, this disclosure is not limited thereto.

[0126] refer to Figure 8 (e) Valves can be installed for injecting or discharging fluid, and through-wires can be provided for electrically connecting the ASSPC within the chamber. Because fluids (especially gases) are more compressible than solids, the IPCH can easily adapt to cell volume changes during cycling. Furthermore, even in environments with significant temperature fluctuations, a pressure regulation system using pressurized fluids and gases can be used to maintain and achieve a constant cycling pressure within the IPCH over extended periods.

[0127] Reference Figure 9 This illustrates an unmodified UPCH and an improved UPCH with a spring and rubber gasket. Specifically, Figure 9 (a) shows an unadorned UPCH with only bolts and nuts. Figure 9 (b) shows an improved UPCH with springs and rubber gaskets. Pressure paper can be clamped in each cell holder to observe the pressure distribution.

[0128] Reference Figure 10 The diagram shows the distribution of reflection pressures exerted by various UPCHs and IPCHs. Specifically, Figure 10 (a) shows Figure 9 (a) shows the pressure distribution of an unmodified UPCH with a metallic surface. Figure 10 (b) shows Figure 9(b) shows the improved UPCH pressure distribution with rubber pads and springs. Figure 10 (c) shows Figure 8 (e) shows the pressure distribution of the IPCH. When pressure above a threshold is received, the pressure paper changes color, for example, to red.

[0129] For more details on the pressure distribution on each pressure paper, please refer to [link / reference]. Figure 11 (a), (c), and (e) correspond to respectively Figure 10 (a), (b) and (c).

[0130] When applying torque to an unfinished UPCH, a torque wrench can be used to apply torque to all four nuts sequentially, gradually increasing the torque value with each rotation to ensure the metal plate remains parallel. However, as Figure 11 As shown in (a), unmodified UPCH may exhibit uneven pressure distribution. This is because, as Figure 11 As shown in (b), when uniaxial pressure is applied using a rigid surface (e.g., bare metal), areas that are not in contact (e.g., the edge of an ASSPC or a recessed area formed by poor flatness of a metal plate surface) will experience lower pressure or be completely unaffected by pressure.

[0131] Improving the UPCH can alleviate these problems of the unmodified UPCH to some extent because the rubber gasket can conform to the shape of the metal plate and ASSPC. However, as... Figure 11 As shown in (c), a uniform pressure distribution was still not observed because, as Figure 11 As shown in (d), in areas with larger gaps, the rubber gasket may deform less, resulting in lower pressure in these areas.

[0132] At the same time, IPCH improves the uniformity of circulating pressure. Figure 5 This illustrates one aspect of IPCH.

[0133] Reference Figure 5 Air is chosen as the pressurizing medium because it is readily available and inexpensive. The pressure paper is vacuum-sealed into a bag and pressurized within the IPCH, with the pressure distribution as shown. Figure 11 As shown in (e), it exhibits a uniform pressure distribution, such as Figure 11 As shown in (f), this is due to Pascal's principle, which states that a pressure change applied at any point in a stationary confined fluid will be transmitted to all directions of the fluid without attenuation.

[0134] Furthermore, when the positive electrode size is 3.5 x 1.5 cm... 2 The surface area capacity is 4 mAh cm⁻¹ -2When NCM811 | Li6PS5Cl(LPSCl) | Si ASSPC is subjected to uniaxial pressure and isostatic pressure at 500 MPa calendering, pressurized through three types of bag-type cell supports, and cycled at 5 MPa at ambient temperature, Figure 11 (g) shows the voltage curve for the second cycle. Figure 11 (g) shows the reversible charging capacity of the ASSPC.

[0135] The cyclic pressure of the UPCH can be measured using the torque values ​​of the bolts and nuts, while the cyclic pressure of the IPCH can be measured by observing a pressure gauge. (Refer to...) Figure 11 (g) As can be seen from the voltage curve of the second cycle, if a rigid metal surface (unmodified IPCH) is used to apply uniaxial pressure, the cell with unmodified IPCH pressure performs poorly during charging, which may be due to poor pressure uniformity; while the cell with modified UCPH and ICPH pressure can successfully complete 100 cycles. Because IPCH provides better pressure uniformity and does not cause material fatigue that can lead to a decrease in cycle pressure over time, IPCH can provide a higher discharge capacity and lower capacity loss for the cell in 100 cycles compared to modified UPCH.

[0136] Figure 12 A comparative schematic diagram of various cell stacks is shown. Specifically, Figure 12 (a) illustrates a cell stack of one aspect of this disclosure. Figure 12 (b) indicates the cell stack placed in the cylindrical UPCH. Figure 12 (c) indicates the bending of the UPCH board when the UPCH board thickness is insufficient. Figure 12 (d) indicates the cell stack in the IPCH. The dimensions of the cell stack can be 20 x 10 x 10 cm. 3 In various aspects of this disclosure, the energy density of an IPCH at the module level can be higher than that of an UPCH. Compared to an UPCH, an IPCH avoids two physical limitations. First, the number of cells in a cell stack can be greater in an UPCH than in an IPCH, and since no pressure plate is used in an IPCH, the bending of the pressure plate in an UPCH is avoided. Furthermore, in various aspects of this disclosure, the configuration of one or more cell stacks can be one of the following: a single-cell stack where individual sheets are stacked sequentially; a Z-shaped stack where one sheet is continuously placed between other sheets; cylindrical winding and square winding of the sheets, but the aspects of this disclosure are not limited to these.

[0137] Reference Figure 12(b) When using a UPCH, pressure must be transmitted through the other ASSPCs. Therefore, all ASSPCs (including all layers within the bag) must be perfectly aligned, which becomes increasingly challenging as the number of cells in a single stack increases. (Refer to...) Figure 12 (c) The pressure plate must be thick enough to resist bending, which may result in higher pressure applied to the edges and lower pressure applied to the center of the ASSPC.

[0138] On the other hand, because the IPCH uses fluid as the pressurizing medium, pressure is applied evenly to all points in all directions. Therefore, deformation of the container walls and the arrangement of the ASSPCs do not affect the uniformity of pressure. Consequently, the IPCH can use thinner walls to reduce module weight. Figure 6 The document shows the estimated weight required for UPCH and IPCH using different metal alloys and pressure ratings from 1 MPa to 10 MPa. Specifically, Figure 6 The graph shows the weight-pressure rating relationship between UPCH and IPCH, where, Figure 6 (a) shows the relationship diagram for 304 steel. Figure 6 (b) shows the relationship diagram for 7075 aluminum alloy. Figure 6 (c) shows the relationship diagram of Ti-6Al-4VTi alloys with different densities, yield strengths, and Young's moduli. Figure 6 As shown, for each alloy, for the same density, yield strength, and Young's modulus, IPCH is significantly lighter than UPCH. Therefore, compared to UPCH, IPCH has advantages in aspects such as energy density. However, the aspects of this disclosure are not limited thereto.

[0139] When using polymers and composites that typically exhibit high elastic strength and low Young's modulus, IPCH can offer a greater weight advantage over UPCH. The use of ASSPC specifications with higher energy density (such as gel rolls and Z-stacks) further enhances the advantages of IPCH, as there are fewer shape constraints on the isostatic press.

[0140] refer to Figure 6 Pressure rating charts for 304 stainless steel, 7075 aluminum alloy, and Ti-6Al-4V are provided, but this disclosure is not limited thereto. For example, any lightweight and tough material, such as carbon fiber or glass fiber, can be used to make IPCH more competitive. However, this disclosure is not limited thereto. Table 3 summarizes the mechanical properties of 304 stainless steel, 7075 aluminum alloy, and Ti-6Al-4V.

[0141] Table 3.

[0142] like Figure 13 As shown, the cycling pressure characteristics of the ASSPC using IPCH are provided. Cycling pressure characteristics at 30°C are provided to avoid environmental temperature fluctuations and ensure stable cell performance.

[0143] exist Figure 13 In the figure, (a) shows the reversible discharge capacity of the pouch cell under different operating pressures and current densities; (b) shows the capacity retention and coulombic efficiency of the pouch cell manufactured at 500 MPa and cycled at 5 MPa, 3 MPa and 2 MPa; and (c) shows the fitting results of the electrochemical impedance spectroscopy (EIS) of the pouch cell after the first and 100th cycles at 50% charge.

[0144] Reference Figure 13 (a) All ASSPCs were activated at 5 MPa during the first cycle, subsequently reduced to the target cycling pressure. At 0.1 C, cells cycled at all pressures except 1 MPa exhibited approximately 160 mAh g⁻¹. -1 Similar discharge capacities were observed, with slight differences attributable to batch variations in the cathode composite. 2 MPa is the minimum cycling pressure required to maintain good interfacial contact in the ASSPC. The effect of cycling pressure becomes significant when the C rate exceeds 0.3 C. At 1 C, cell polarization increases sharply, and only 30 mAh g⁻¹ can be achieved at a cycling pressure of 5 MPa. -1 However, when the C rate drops back to 0.1 C, the ASSPC, after more than 2 MPa cycles, can recover most of its discharge capacity. (Refer to...) Figure 13 (b) and (c) allow for the selection of three cycling pressures: 5 MPa, 3 MPa, and 2 MPa, for long-term cycling at 0.2 C. This current is moderate enough to differentiate the effect of cycling pressure on capacity retention without causing a significant degradation in discharge capacity at rate. As coulombic efficiency decreases, more cycles are required to achieve near-100% coulombic efficiency, and the initial discharge capacity decreases from 149.7 mAhg at 5 MPa. -1 Reduced to 135.37 mAh g at 2 MPa -1 Due to the loss of interfacial contact, the capacity retention after 100 cycles deteriorates from 77.8% at 5 MPa to 47.7% at 2 MPa. Since the electrode material undergoes repeated volume changes, pressure needs to be applied to maintain physical contact between the SSE and the electrode material, and higher pressure is more conducive to maintaining tight interfacial contact.

[0145] Figure 14The Nyquist plot shows a pouch cell manufactured at 500 MPa and cycled at 5 MPa, 3 MPa and 2 MPa using an IPCH.

[0146] Reference Figure 14 (a) shows the electrochemical impedance spectroscopy (EIS) spectrum of the pouch cell at 50% charge during the first cycle; (b) shows the EIS spectrum of the pouch cell at 50% charge during the 100th cycle. Figure 13 (c) The electrochemical impedance spectroscopy (EIS) spectra of the three ASSPCs were fitted at the 1st and 100th cycles (see Tables 4 and 5 below).

[0147] The diagram lists four components, from high to low frequency: the bulk, the SSE grain boundary interface, the positive electrode, and the negative electrode. In the first cycle, the positive and negative electrode components are combined. All ASSPCs exhibit similar SSE impedance values ​​at different cycling pressures and cycles, indicating that the SSE membrane layer is stable during cycling and insensitive to cycling pressure. In the first cycle, the combined impedance of the positive and negative electrodes exhibits high impedance. After 100 cycles, the negative electrode impedance increases significantly due to the large volume change of Si and the formation of the solid electrolyte interface (SEI). The positive electrode experiences less volume change during cycling and is protected by the Li3BO3 coating, resulting in a more gradual impedance increase. When the cycling pressure is reduced from 5 MPa to 3 MPa and 2 MPa, the impedance of both the positive and negative electrodes approximately doubles. Maintaining good interfacial contact with appropriate cycling pressure is crucial. In various aspects of this disclosure, volume changes can occur in the positive and negative electrodes, including up to 5% volume change for the NCM811 positive electrode and, for the negative electrode, per 1 mAh cm⁻¹. -2 The Li has a diameter of 5 µm, while for Si it is at most 400 µm.

[0148] Table 4

[0149] Reference Figure 15(a) shows the EIS results of the ASSPC after 100 cycles at 5 MPa, followed by pressure reduction to 1 MPa, restoration to 5 MPa, and then calendering at 500 MPa; (b) shows the capacity retention and CE of the pouch cell before and after calendering, and after cycling at 5 MPa; (c) shows the average discharge capacity of the pouch cell, which underwent rate testing at 1 MPa, calendering at 500 MPa, and another rate test at 5 MPa; and (d) depicts the change in contact loss between the SSE and the positive electrode when insufficient pressure is applied. Even after restoring the pressure to its initial value, the original state cannot be restored. The outer circle marks the friction points, and the inner circle marks the gaps. As shown, higher pressure must be applied to restore contact between particles.

[0150] Figure 16 To show Figure 15 (a) is a schematic diagram of the pressurization process. Figure 17 The impedance diagram is for a pouch cell that has been cycled 100 times at 5 MPa. The applied pressure in the IPCH is then reduced from 5 MPa to 1 MPa, and then restored to 5 MPa. After measurement, a manufacturing pressure of 500 MPa can be applied to the pouch cell, and the EIS can be measured at 5 MPa.

[0151] therefore, Figure 16 , 17 Table 5 shows the impedance changes of the ASSPC under pressure variations as the pressure is reduced from 5 MPa to 1 MPa, then restored to 5 MPa, and finally re-calcined at 500 MPa for 100 cycles.

[0152] Table 5

[0153] Figure 18 A graph showing the discharge capacity of an ASSP PC after cycling at 1 MPa, then being repressurized at 500 MPa, and finally measured again at 5 MPa. Similar rate performance to that of an ASSP PC initially cycled at 5 MPa can be obtained.

[0154] Reference Figure 18As the pressure decreases, the impedance of all cell components gradually increases. When the pressure decreases from 5 MPa to 1 MPa, although the impedance of the SSE separator layer increases by 1.7 times at a slow rate, the impedances of both the positive and negative electrodes can increase by approximately 2.5 times. Even when the pressure returns to 5 MPa, the impedance of the ASSPC cannot recover. To understand this phenomenon, the ASSPC can be re-calendered, and a significant reduction in impedance can be observed. It is smaller than the initial stage after 100 cycles, but larger than that in the first cycle. The re-calendered ASSPC can be cycled again, and its discharge capacity can be increased from 116.5 mAh g⁻¹ in the 100th cycle. -1 Partially restored to 141.2 mAh g at the 101st cycle. -1 (Still see) Figure 15 (b)). To further demonstrate the effect of recalendering, the ASPC, which underwent rate performance testing at 1 MPa, was recalendered and cycled again at 5 MPa. Its performance was almost completely recovered, similar to that of the ASPC that was initially cycled at 5 MPa (see [link]). Figure 15 (c) and Figure 18 ). Figure 15 (d) illustrates a schematic diagram using the positive electrode complex as an example to describe impedance changes. When the applied pressure decreases, the SSE and positive electrode particles undergo elastic deformation and partially extend into the low-pressure state. This creates larger gaps, resulting in poorer interfacial contact and thus increased cell impedance. Even with the reapplication of the initial pressure, some gaps cannot close because overcoming interparticle friction requires even greater pressure (re-rolling). Nevertheless, impedance cannot be fully recovered because an SEI and positive electrode electrolyte interface (CEI) have formed after long cycling.

[0155] Reference Figure 19 (a) shows a schematic diagram of the double-layer pouch cell configuration and a cross-sectional view obtained by plasma-focused ion beam scanning electron microscopy (P-FIB SEM); (b) shows the voltage curves of the pouch cell at different cycle numbers; (c) shows a 3 x 3.5 cm... 2 The capacity retention of the double-layer ASSPC is shown in Figure (d), which shows the double-layer ASSPC in the IPCH powering an incandescent bulb with a rated input of 2.5 V – 300 mA under cyclic isostatic pressure of 5 MPa.

[0156] Reference Figure 19 The total positive electrode area of ​​a double-layer ASSPC can be 21 cm². 2 The theoretical area capacity can be approximately 5 mAh cm⁻¹. 2It can be cycled at 30℃, 0.1 C, and 5 MPa. The cells can be stacked in the following order: Cu – Si – SSE – NCM811 – Al – NCM811 – SSE – Si – Cu. FIB-SEM cross-sectional views and details of the cell specifications are shown below. Figure 19 As shown in (a), the initial coulombic efficiency of the bilayer ASSPC is 76.9%, and the discharge capacity is 173.6 mAh g⁻¹. -1 (88.1 mAh). For example... Figure 19 As shown in (b) and (c), it still maintains 145 mAh g after 100 cycles. -1 The discharge capacity. Figure 19 (d) A sample of the power performance of the dual-layer ASSPC is shown by powering an incandescent bulb rated at 2.5 V and 300 mA. When using an LED lamp, the forward bias of a small red LED can be 2 V, requiring as little as 3 mA of current in some cases. The dual-layer ASSPC can operate at 3 C. Multiple ASSPCs can be housed within the IPCH in its chamber and can be available in various configurations and shapes.

[0157] Cyclic pressure is required to maintain good interfacial contact in the ASSB, and the IPCH can provide this cyclic pressure via a medium (such as compressed air), thereby applying isostatic pressure to the ASSPC. The IPCH can provide a significantly more uniform pressure distribution than rigid metal surfaces or flexible rubber gaskets. Because fluids do not suffer from material fatigue like many elastic materials, the cyclic pressure of the IPCH can remain stable over long periods, resulting in better capacity retention of the ASSPC than with an UPCH over more than 100 cycles.

[0158] Because fluids can be used within the IPCH, thinner walls can be constructed, and a variety of ASSPC specifications with higher energy densities can be used. Examples of ASSBs include NCM811|LPSCl|Si ASSPCs that can cycle under a wide range of pressures. The minimum required cycling pressure can be as low as 2 MPa to maintain adequate interfacial contact within the cell, and the cell can cycle at 1 C and complete 100 cycles at 0.2 C. The rate performance and capacity retention of the ASSPC are positively correlated with the cycling pressure. A bilayer ASSPC with a capacity of approximately 100 mAh can cycle at 0.1 C and complete 50 cycles. The cell can discharge at a rate of 3 C (300 mA), but this disclosure is not limited to this. Isostatic cycling of the cell can provide a uniform and accurate pressurization method for the commercialization of ASSBs.

[0159] In various aspects of this disclosure, the ASSPC used can be for dry-processed LiNi 0.8 Co 0.1 Mn 0.1 O2 (or NCM811) cathode composite, dry-processed Li6PS5Cl (or LPSCl) SSE membrane, and slurry-processed Si anode. The NCM811 cathode composite can be processed by mixing NCM811, LPSCl, vapor-grown carbon fiber (VGVF, Sigma-Aldrich), and polytetrafluoroethylene (PTFE) in a mortar at a weight ratio of 66:31:3:0.1 until lumps are formed. The lumps can then be transferred to a hot roller (TMAXCN) set to 60°C to fabricate the membrane. Shear forces can be applied during mixing and rolling to fiberize the PEFE and strengthen the membrane. Similar steps can be applied to fabricate the LPSCl SSE membrane at a weight ratio of LPSCl:PTFE = 99.9:0.1. To prepare the µ-Si electrode, 99.9 wt% µ-Si (Thermofisher) powder and 0.1 wt% PVDF binder were dispersed in N-methyl-2-pyrrolidone (NMP) solvent using a Thinky stirrer to form a slurry. The slurry was then cast onto a 10 µm copper foil current collector using a doctor blade on an automated coating machine. The electrode was allowed to dry continuously at 80°C for several hours to remove the solvent. The dried electrode was then punched to the appropriate size for use in ASSPC assembly.

[0160] Reference Figure 20 This shows the use of 150 MPa (see...) Figure 20 (a)), 350 MPa (see Figure 20 (b) and 500 MPa (see Figure 20 (c) A graph showing the capacity retention and coulombic efficiency of the manufactured pouch cells. Segmented FIB cross-sectional diagrams and porosity are shown below. Figure 20 As shown in (d) to (f). Furthermore, Figure 20 (g) shows the measurement results of the first EIS cycle. Figure 20 (h) shows the measurement results of the 30th EIS cycle.

[0161] refer to Figure 21 The diagram shows the P-FIB cross sections of the NCM811 cathode composite calendered at (a) 150 MPa, (b) 350 MPa, and (c) 500 MPa, respectively, corresponding to... Figure 20 (d), (e) and (f).

[0162] refer to Figure 22According to several aspects of this disclosure, a method for using isostatic cells is provided. Starting with operation S2210, the cell can be activated in operation S2220 once manufactured or formed. Then, in operation S2230, the activated cell can be pressurized during use (e.g., during charging and discharging). The method can end at operation S2240. In various aspects of this disclosure, a pouch-type cell holder (e.g., UPCH or IPCH) can be used to activate and / or pressurize the cell. In a specific example, in at least one of operations S2220 and S2230, the cell (including ASSB) can be activated and / or pressurized via the IPCH.

[0163] Figure 23 A battery pack 1000, representing one aspect of this disclosure, is shown. (See figure) Figure 1 and / or Figure 5 As shown, the battery pack 1000 can be used with a battery cell pressurization device. For example, the battery pack 1000 may include, for example, Figure 1 and / or Figure 5 The battery cell pressurization device shown is illustrated. Furthermore, the battery pack 1000 may include two or more battery cells.

[0164] Cell specifications for electrochemical characterization of cells and bilayer cells can be as follows. Cell specifications may include a positive electrode composite film with dimensions of 15 mm x 35 mm x 160 µm, thereby producing a 4 mAh cm⁻¹. -2 The cell consists of an area-loaded SSE membrane measuring 18 mm x 40 mm and 300 µm, and a Si anode measuring 18 mm x 37 mm with an NP ratio of 1.2. The positive electrode composite membrane can have the smallest area and can serve as the capacity-limiting component, while the SSE membrane can have the largest area to electronically isolate the positive and negative electrodes. To assemble the electrochemically characterizing cell, Cu, Si, LPSCl, NCM811 positive electrode composite, and Al can be stacked from bottom to top and secured with Kapton tape. Al tabs can be soldered to Al current collectors as positive terminals, and Ni tabs can be soldered to Cu current collectors as negative terminals, with a width of 4 mm between the two terminals. The entire stack can then be vacuum-sealed in an Al laminate and calendered using a cold isostatic press.

[0165] like Figure 20 and Figure 21As shown, ASSPC calendered at 150 MPa, 350 MPa, and 500 MPa can be cycled and characterized. Among these pressures, 500 MPa can be used as the cycling pressure to calender ASSPC, and good electrochemical performance can be obtained. Cycling pressure can be applied after calendering. In the bilayer cell, the size of the positive electrode composite film can be 30 mm x 35 mm x 200 µm, thereby achieving a 5 mAh cm⁻¹. -2 With a good areal load, the SSE separator can be 35 mm x 40 mm 300µm in size, and the Si anode has an NP ratio of 1.2 and a size of 35 mm x 37 mm. The components of the double-layer cell can be stacked in the following order: Cu, Si, LPSCl, NCM811 cathode composite, Al, NCM811 cathode composite, LPSCl, Si and Cu.

[0166] ASSPC calendered at 150 MPa, 350 MPa, and 500 MPa can be cycled 100 times at ambient temperature with fluctuating coulombic efficiency and capacity retention. Higher capacity retention can be obtained with increasing manufacturing pressure due to increased interfacial contact. See the P-FIB / SEM cross-sectional diagram (see...). Figure 21 As manufacturing pressure increases, porosity decreases. EIS results from the first and 30th cycles also show that cell impedance decreases under higher manufacturing pressure, which explains the battery capacity retention results.

[0167] For analysis, a Neware A211-BTS-4S-1U-100mA-124 battery cycler and a Biologic VSP-300 were used for constant current cycling and EIS measurements. The NCM811|Si system can have a cutoff voltage ranging from 2 V to 4.3 V. Since the diffusion of Li in pure Si can be improved after lithiation, activation cycling can be introduced in all test schemes. In activation cycling, the ASSPC can be cycled at 0.05 C for 5 hours, then the entire cycle is completed at 0.1 C. A pressure of 5 MPa can be applied during activation cycling, subsequently reduced to the target pressure. To obtain accurate cycling, all ASSPCs can be cycled in an oven set to 30°C to study the effect of cycling pressure, but this disclosure is not limited to this. Other temperatures are also possible within the scope of this disclosure, ranging from as low as 100°C to as high as 300°C. Rate performance testing can be performed by running the ASSPC at 0.1 C, 0.2 C, 0.3 C, 0.4 C, 0.5 C, 0.7 C, 1 C, and 0.1 C, with each C rate subjected to three cycles at pressures ranging from 5 MPa to 1 MPa. During long-term cycling, the ASSPC can cycle at 0.2 C, and a constant voltage step can be applied up to 0.05 C at the end of charging. The ASSPC can be run up to 100 cycles, and during discharge, EIS can be obtained at 50% state of charge in the first and 100th cycles. EIS results can be analyzed using Z-View software. The dual-layer ASSPC can cycle at 0.1 C, and a constant voltage step can be applied up to 0.05 C at the end of charging.

[0168] Cross-sectional images of ASSPC can be obtained using a Helios G4 PFIB UXeDualBeam plasma-focused ion beam / scanning electron microscope (P-FIB / SEM) with a xenon source. After calendering, the ASSPC can be decomposed, and its cathode composite can be attached to the SEM sample stage (stub) and sealed in an argon-filled glove box. It can then be transferred to the P-FIB / SEM after 30 seconds of exposure to air on the sample stage. Sample grinding can be performed at 30 kV and 2.5 µA. The cross-section can then be polished using lower currents (500 nA and 60 nA). Electron imaging can be performed under 5 kV and 4 nA beam current conditions. To segment the P-FIB / SEM images, they can be imported into the Trainable Weka SegmentationFiji module to identify NMC811, LPSCl, and pores. Segmentation can rely on a machine learning algorithm manually trained by the user from the input images. The phase ratio can then be calculated in MATLAB. The image of the pressure paper can also be processed based on the image of the pressure paper. In MATLAB, the results can be recalibrated using the ratios of red, green, and blue in each pixel of the JPG file.

[0169] Figure 24 A schematic diagram of an all-solid-state battery (SSB) according to one aspect of this disclosure is shown. Various aspects of the solid-state battery (SSB) will be discussed below.

[0170] Overview of Lithium-ion Batteries

[0171] Solid-state batteries (SSBs) can be charged multiple times and discharged to an external electrical load. A solid-state battery 1101 includes electrodes (e.g., a positive electrode 1130 and a negative electrode 1120) and an electrolyte layer 1140, allowing lithium ions to move between the electrodes. Unlike conventional liquid electrolyte batteries, solid-state batteries (SSBs) do not contain any flowing liquid. The formation of a circuit between the electrodes causes current to flow between them. During charging of a lithium-ion rechargeable battery, lithium ions are released from the positive electrode and inserted into the active material of the negative electrode. During discharging of a lithium-ion rechargeable battery, lithium ions are released from the negative electrode and inserted into the active material of the positive electrode. As lithium ions reciprocate between the electrodes, they transfer energy.

[0172] Solid-state battery configuration

[0173] This disclosure provides an all-solid-state battery 1101 comprising a positive electrode 1130, a negative electrode 1120, and a solid electrolyte layer 1140 located between the positive electrode 1130 and the negative electrode 1120. Although listed by way of example, the solid-state battery 1101 does not require all of these components. For example, in some configurations, such as in an anode-free system, the negative electrode 1120 may be omitted. Alternatively, according to aspects of this disclosure, the negative electrode 1120 may comprise a negative electrode material having a metal-carbon composite, such as a silver-carbon mixture or composite, wherein the silver particles are composited with amorphous and / or crystalline carbon particles. Although silver is used as an example, other metals may also be used, including, for example, tin, silicon, zinc, or combinations thereof, but aspects of this disclosure are not limited thereto.

[0174] Solid-state battery 1101 may optionally include one or more additional layers, such as a separator layer, a protective layer, an inhibitor layer, a solid electrolyte interface layer, or a combination thereof. For example, a protective layer may be included between the electrode and the solid electrolyte layer. This protective layer may contain materials such as lithium phosphate, lithium titanate, or lithium lanthanum zirconium oxide (LLZO), which can help prevent undesirable side reactions at the electrode-electrolyte interface. The protective layer can also be used to mitigate dendrite formation, particularly on the negative electrode side, thereby improving the overall cycle life and safety of the battery. A separator layer may also be included in some configurations of solid-state batteries. Conventional liquid electrolyte batteries typically use porous polymer separators, while solid-state batteries may employ thin ceramic or glass-ceramic layers as separators. These separator layers can provide additional mechanical support for the battery structure while still allowing efficient ion transport. Materials such as LLZO, LATP (lithium aluminum titanium phosphate), or LAGP (lithium aluminum germanium phosphate) can be used for this purpose, but this disclosure is not limited thereto. The separator layer may also be designed with a gradient structure whose performance is optimized for contact with the positive and negative electrode materials, but this disclosure is not limited thereto.

[0175] Battery cell configuration

[0176] Figure 24A solid-state battery 1101 comprising a single cell 1001 is shown. In other examples, the solid-state battery 1101 may include multiple cells, such as at least two cells, at least three cells, or at least four cells. Connecting cells in series increases the voltage of the solid-state battery 1101, while connecting cells in parallel increases the ampere-hour capacity of the solid-state battery 1101. In some embodiments, the solid-state battery 1101 may be configured using a combination of series and parallel connections to achieve desired voltage and capacity characteristics. For example, multiple batteries may be arranged in groups, with the cells within each group connected in parallel to increase capacity, and then these groups may be connected in series to increase voltage. This configuration (sometimes referred to as a series-parallel arrangement) provides greater flexibility in battery design and can help optimize performance for specific applications. Furthermore, the number and arrangement of cells can be adjusted to meet the needs of various form factors.

[0177] Cell thickness

[0178] The thickness t1 of the battery cell 1001 can be 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 400 μm, 500 μm, 1000 μm, 2000 μm, or 5000 μm. In various embodiments, the thickness t1 of the battery cell 1001 can be within a range selected from the two numbers listed in the preceding sentence, for example, between 100 μm and 5000 μm, or between 100 μm and 1000 μm, but this disclosure is not limited thereto.

[0179] Positive electrode overview

[0180] The positive electrode 1130 corresponds to a polarity (e.g., positive polarity) of the solid-state battery 1101. The positive electrode 1130 is configured as the positive electrode during discharge of the solid-state battery 1101. The positive electrode 1130 facilitates lithium-ion diffusion between the current collector 1160 and the solid electrolyte layer 106. The positive electrode 1130 is electrically connected to the current collector 1160. In several embodiments, the positive electrode 1130 is formed above and in direct contact with the current collector 1160. In other embodiments, another functional layer may be provided between the positive electrode 1130 and the current collector 1160, but this disclosure is not limited thereto.

[0181] Materials for the positive electrode

[0182] The positive electrode 1130 is capable of reversibly inserting and deintercalating lithium ions. For example, the positive electrode 1130 may include one or more of the following: positive electrode active material, conductive carbon, solid electrolyte material, binder, etc., or combinations thereof. Optionally, the positive electrode 1130 may also include additives, such as oxidation stabilizers, reduction stabilizers, flame retardants, heat stabilizers, antifogging agents, thickeners, etc., or combinations thereof, but this disclosure is not limited thereto. Examples of such additives include: butylated hydroxyanisole (BHA) or butylated hydroxytoluene (BHT) as oxidation stabilizers; ascorbic acid or sodium sulfite as reduction stabilizers; aluminum hydroxide or magnesium hydroxide as flame retardants; phenolic compounds or phosphites as heat stabilizers; polyethylene glycol or silica nanoparticles as antifogging agents; and carboxymethyl cellulose (CMC) or xanthan gum as thickeners, but this disclosure is not limited thereto.

[0183] Materials for positive electrode active materials

[0184] Positive electrode active materials may include lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), and Li[Ni a Co b Mn c M 1 d O2 (where M) 1 For any element or combination thereof composed of Al, Ga, and In, 0.3≤a<1.0, 0≤b≤0.5, 0≤c≤0.5, 0≤d≤0.1, a+b+c+d=1), Li (Li e M 2 f-e-f M 3 f′ )O 2-g A g (where 0≤e≤0.2, 0.6≤f≤1, 0≤f′≤0.2, 0≤g≤0.2, M) 2 Including Mn and at least one element selected from the group consisting of Ni, Co, Fe, Cr, V, Cu, Zn, and Ti, M 3 A is at least one element selected from the group consisting of Al, Mg, and B, and A is at least one element selected from the group consisting of P, F, S, and N; or those compounds substituted by one or more transition metals; compounds with the chemical formula Li 1+h Mn 2-h Lithium manganese oxides represented by O4 (where 0≤h≤0.33), LiMnO3, LiMn2O3, LiMnO2, etc.; lithium copper oxides (Li2CuO2); vanadium oxides, such as LiV3O8, V2O5, or Cu2V2O7; and those represented by the chemical formula LiNi. 1-i M 4i O2 (where M) 4 =Co, Mn, Al, Cu, Fe, Mg, B or Ga, 0.01≤y≤0.3) represents Ni-site type lithium nickel oxide; LiMn 2-j M 5 j O2 (where M) 5 =Co, Ni, Fe, Cr, Zn or Ta, 0.01≤y≤0.1) or Li2Mn3M 6 O8 (where M) 6 Lithium manganese composite oxides represented by (Fe, Co, Ni, Cu or Zn); LiMn2O4, wherein lithium is partially substituted by alkaline earth metal ions; disulfide compounds; LiFe3O4, Fe2(MoO4)3, etc.; or combinations thereof, but the aspects of this disclosure are not limited thereto.

[0185] Besides the aforementioned cathode active materials, the cathode can also contain other types of materials. For example, lithium iron phosphate (LiFePO4) can be used as a cathode active material due to its excellent thermal stability and long cycle life. Other phosphate-based materials, such as lithium manganese iron phosphate (LiMn), are also suitable. x Fe 1-x Lithium cobalt phosphate (LiCoPO4) or lithium cobalt phosphate (LiCoPO4) may also be used, but this disclosure is not limited thereto.

[0186] Positive electrode active materials can also include layered oxide materials with various compositions, such as Li(Ni) 1-x- y Co x Mn y O2 (NCM) or Li (Ni) 1-x-y Co x Al y O2 (NCA), in which the proportions of Ni, Co, Mn, and Al can be adjusted to optimize performance characteristics. For example, NCM materials with high nickel content, such as NCM811 (LiNi... 0.8 Co 0.1 Mn 0.1 O2 can be used to achieve higher energy densities. In some cases, the positive electrode active material can include a spinel structure, such as LiNi. 0.5 Mn 1.5 O4 can be used, which can provide operation at high voltages. Alternatively, materials with a tavorite structure (such as LiFeSO4F or LiVPO4F) can be used because of their potential for high energy density and good thermal stability, but this disclosure is not limited to these.

[0187] Composite or mixed cathode materials combining two or more active materials can also be used. For example, a mixture of layered oxides and spinel materials can be used to balance energy density and power performance. As another example, lithium iron phosphate can be mixed with one or more of the above-mentioned cathode active materials. In some embodiments, the cathode active material may include a surface-modified form of the above-mentioned compounds, wherein the surface modification is intended to improve stability, conductivity, or other performance indicators, but this disclosure is not limited thereto.

[0188] The cathode active material may also include emerging types of materials, such as disordered rock salt structures (e.g., Li3NbO4-based materials) or high-entropy oxides, which can provide a unique combination of high capacity and structural stability. In some cases, the cathode active material may include dopants or substituents to further tune its electrochemical performance, but this disclosure is not limited thereto.

[0189] Particle properties of positive electrode active materials

[0190] The positive electrode active material can be in particulate form. The positive electrode active material can include the following particle sizes: 10 nm, 20 nm, 30 nm, 50 nm, 70 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 1000 nm, 10 μm, 20 μm, 30 μm, 50 μm, 70 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, or 1000 μm. In several embodiments, the particle size of the positive electrode active material can be within a range selected from the two numbers listed in the preceding sentence, for example, between 10 nm and 1000 μm. The gaps between the positive electrode active materials in the positive electrode 1130 can be filled with a solid electrolyte material, but this disclosure is not limited thereto.

[0191] The amount of positive electrode active material in the positive electrode

[0192] The content of the positive electrode active material in the solid-state battery 1101 affects the charge and discharge capacity of the solid-state battery 1101. To manufacture a high-capacity positive electrode 1130, a high level of positive electrode active material can be included in the positive electrode 1130. For example, the positive electrode 1130 may contain approximately or greater than 30 wt%, 40 wt%, 50 wt%, 60 wt%, 70 wt%, 80 wt%, 90 wt%, 95 wt%, or 98 wt% of positive electrode active material based on the total weight of the positive electrode 1130. In various embodiments, the positive electrode active material in the positive electrode 1130 may be within a range selected from the two figures listed in the preceding sentence, for example, between 40 wt% and 98 wt%, but aspects of this disclosure are not limited thereto.

[0193] Materials used for conductive materials in the positive electrode

[0194] There are no particular limitations on the conductive material in the positive electrode 1130, as long as it is conductive and does not cause any chemical changes in the corresponding solid-state battery 1101. For example, conductive materials may include: graphite, such as natural or artificial graphite; carbon black, such as acetylene black, Ketjen black, channel black, furnace black, lamp black, or thermally cracked carbon black; conductive fibers, such as carbon fibers or metal fibers; carbon nanotubes (CNTs), including single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs); fluorocarbon powders; metal powders, such as aluminum or nickel powders; conductive whiskers, such as zinc oxide or potassium titanate; conductive metal oxides, such as titanium oxide; conductive materials, such as polystyrene derivatives; or combinations thereof. Other conductive materials that can be used in the positive electrode 1130 include graphene and its derivatives, such as reduced graphene oxide (rGO) or graphene nanosheets, but this disclosure is not limited to these. These two-dimensional carbon materials provide high surface area and excellent electrical conductivity. Conductive polymers that can improve the conductivity of the electrode while also enhancing its mechanical properties, such as polyaniline (PANI), polypyrrole (PPy), or poly(3,4-ethylenedioxythiophene) (PEDOT), can also be used. In some cases, mixed conductive additives combining different materials, such as CNT-graphene composites or metal-coated carbon materials, can be used to synergistically improve the overall conductivity and performance of the cathode 1130, but this disclosure is not limited thereto.

[0195] The amount of conductive material in the positive electrode

[0196] The positive electrode 1130 comprises 1 wt%, 2 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, or 30 wt% of conductive material based on the total weight of the positive electrode 1130. In various embodiments, the conductive material in the positive electrode 1130 may be within a range selected from the two figures listed in the preceding sentence, for example, between 1 wt% and 30 wt%, but aspects of this disclosure are not limited thereto.

[0197] Materials for adhesives

[0198] The adhesive can include various types of adhesive polymers, such as polyvinylidene fluoride-hexafluoropropylene copolymer (PVdF-co-HFP), polyvinylidene fluoride, polyacrylonitrile, polymethyl methacrylate, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, polyacrylate, ethylene-propylene-diene polymer (EPDM), sulfonated EPDM, styrene-butadiene rubber (SBR), fluororubber, polyacrylic acid, and polymers in which hydrogen atoms are substituted with Li, Na, or Ca, various copolymers thereof, or combinations thereof, but this disclosure is not limited thereto. In addition to the adhesive materials mentioned above, other types of adhesive materials can be used in the positive electrode to enhance its performance and stability. For example, water-soluble adhesives such as sodium alginate, gelatin, or polyacrylamide can be used to improve the environmental friendliness of the electrode manufacturing process. These adhesives can also provide advantages in electrode flexibility and adhesive strength. In some cases, conductive adhesives such as poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) or polyaniline (PANI) can be used to simultaneously improve the mechanical integrity and conductivity of the electrode. Novel adhesive systems, such as self-healing polymers or supramolecular assemblies, can be included to enhance the long-term stability and cycle life of the battery. Furthermore, composite adhesives combining multiple polymers or including inorganic nanoparticles can be used to tune the mechanical, thermal, and electrochemical properties of the electrode. In some embodiments, bio-derived or biodegradable adhesives, such as cellulose derivatives or chitosan, can be used to reduce the environmental impact of battery production and disposal, but this disclosure is not limited thereto.

[0199] Amount of binder in the positive electrode

[0200] The positive electrode 1130 includes a binder at 1 wt%, 2 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, or 30 wt% based on the total weight of the positive electrode 1130. In various embodiments, the binder in the positive electrode 1130 may be in a range selected from the two figures listed in the preceding sentence, for example, between 1 wt% and 30 wt%, but aspects of this disclosure are not limited thereto.

[0201] Materials for solid electrolytes

[0202] The solid electrolyte material in the positive electrode 1130 can be configured separately and identically to the material used for the solid electrolyte layer 106, as discussed below. The solid electrolyte material in the positive electrode 1130 can be the same as or different from the material of the solid electrolyte layer 106.

[0203] The amount of solid electrolyte material in the positive electrode

[0204] The positive electrode 1130 includes 1 wt%, 2 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, or 30 wt% of solid electrolyte material based on the total weight of the positive electrode 1130. In various embodiments, the amount of solid electrolyte material in the positive electrode 1130 may be within a range selected from the two figures listed in the preceding sentence, for example, between 1 wt% and 30 wt%, but aspects of this disclosure are not limited thereto.

[0205] Positive electrode thickness

[0206] The thickness t2 of the positive electrode 1130 can be 10 μm, 20 μm, 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 400 μm, 500 μm, or 1000 μm. In various embodiments, the thickness t2 of the positive electrode 1130 can be within a range selected from the two numbers listed in the preceding sentence, for example, between 10 μm and 1000 μm, but this disclosure is not limited thereto.

[0207] Positive electrode porosity

[0208] The porosity of the positive electrode 1130 can be 0% by volume, 1% by volume, 2% by volume, 3% by volume, 4% by volume, 5% by volume, 6% by volume, 7% by volume, 8% by volume, 9% by volume, 10% by volume, 11% by volume, 12% by volume, 13% by volume, 14% by volume, 15% by volume, 16% by volume, 17% by volume, or 18% by volume, based on the total volume of the positive electrode 1130. In various embodiments, the porosity of the positive electrode 1130 can be within a range selected from the two numbers listed in the preceding sentence, for example, between 0% by volume and 18% by volume, but aspects of this disclosure are not limited thereto.

[0209] Lithium-ion diffusion rate of the positive electrode

[0210] The positive electrode 1130 can include 1 x 10 -14 cm 2 / s, 1 x 10 -13 cm 2 / s, 1 x 10 -12 cm 2 / s, 1 x 10 -11 cm 2 / s, 1 x 10 -10 cm 2 / s, 1 x 10 -9 cm 2 / s, 1 x 10 -8 cm 2 / s or 1 x 10 -7 cm 2 The lithium-ion diffusion rate is 1 / s. In several embodiments, the lithium-ion diffusion rate of the positive electrode 1130 can be within a range selected from the two numbers listed in the previous sentence, for example, 1 x 10⁻⁶. -14 cm 2 / s to 1 x 10 -7 cm 2 / s, but this disclosure is not limited thereto.

[0211] Positive current collector

[0212] The current collector 1160 collects the electrical energy generated by the positive electrode 1130 and supports the positive electrode 1130. The material of the current collector 1160 is not particularly limited, as long as it allows the positive electrode 1130 to adhere, has suitable conductivity, and does not cause significant chemical changes in the solid-state battery 1101 within its voltage range. For example, the current collector 1160 can be made of or comprise various materials, such as metals, conductive carbon, or conductive ceramics, but is not limited thereto. The metal of the current collector 1160 can include one or more, or combinations thereof, selected from the group consisting of aluminum, aluminum alloys, copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, iron, iron alloys (e.g., steel, stainless steel), silver, silver alloys, gold, platinum, palladium, chromium, molybdenum, tungsten, tantalum, niobium, zirconium, vanadium, manganese, cobalt, indium, tin, lead, and bismuth, but is not limited thereto.

[0213] Shape and size of positive current collector

[0214] By forming fine surface irregularities on the surface of the current collector 1160, the adhesion between the positive electrode 1130 and the current collector 1160 can be improved. The current collector 1160 can have various shapes, such as a membrane, sheet, foil, mesh, porous body, foam, nonwoven mesh, etc., or combinations thereof, but this disclosure is not limited thereto. The current collector 1160 can also be configured in various other geometries to optimize its performance and integration with the positive electrode 1130, and its dimensions can be determined for specific morphological specifications, such as bag-shaped, cylindrical, and / or prismatic morphological specifications. For example, the current collector 1160 can be constructed as a mesh or grid, which can provide enhanced mechanical support while maintaining a high surface area for electrode adhesion. In some embodiments, the current collector 1160 can be designed in a corrugated or wavy pattern, thereby increasing the contact area with the positive electrode material and improving overall conductivity. The current collector 1160 can also be made into a perforated sheet, thereby allowing for better electrolyte permeation and ion transport. In some cases, the current collector 1160 can be formed as a three-dimensional structure, such as a fiber interconnect network or a honeycomb structure, which can enhance the structural integrity of the electrode assembly while promoting efficient current collection, but the aspects of this disclosure are not limited thereto.

[0215] Thickness of the positive current collector

[0216] The thickness t3 of the current collector 1160 can be 3 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 50 μm, 100 μm, 150 μm, 200 μm, 300 μm, 400 μm, or 500 μm. In several embodiments, the thickness t3 of the current collector 1160 can be within a range selected from the two numbers listed in the preceding sentence, for example, between 5 μm and 500 μm.

[0217] Method for manufacturing positive electrode

[0218] The positive electrode 1130 can be obtained by various methods. For example, the positive electrode active material can be mixed and stirred with a solvent and optionally a binder, conductive material and dispersant to form a slurry. The slurry is then applied (e.g. coated) onto the current collector 1160, and then pressed and dried to obtain the positive electrode 1130, but the aspects of this disclosure are not limited thereto.

[0219] In addition to the slurry-based method described above, various other techniques can be used to manufacture the positive electrode 1130. For example, a dry powder coating process can be used, in which the positive electrode active material, conductive additives, and binder are mixed in a dry state and then applied directly to the current collector 1160 using electrostatic deposition or mechanical compression. This method eliminates the need for solvents, thus reducing environmental impact.

[0220] In some cases, the positive electrode 1130 can be manufactured using additive manufacturing techniques such as 3D printing. This method allows for precise control of the electrode structure and porosity, thereby improving electrode performance and energy density. Depending on the specific material and desired electrode properties, various 3D printing methods can be employed, including fused deposition modeling (FDM), selective laser sintering (SLS), or direct-write modeling (DIW).

[0221] Another method for manufacturing the positive electrode 1130 involves electrospinning. In this process, a solution containing the positive electrode active material, conductive additives, and polymer binder is extruded through a nozzle under an electric field to form nanofibers. These fibers can be collected directly on the current collector 1160 to form a highly porous electrode structure with an increased surface area.

[0222] In some embodiments, the positive electrode 1130 can be prepared using a tape casting method. This technique involves spreading a slurry of electrode material onto a moving carrier film using a doctor blade, followed by drying and calendering. The resulting electrode tape can then be laminated onto the current collector 1160.

[0223] Alternatively, the positive electrode 1130 can be manufactured using a spraying technique. In this method, a fine mist of electrode slurry is sprayed onto the current collector 1160 using compressed air or ultrasonic atomization. This method can produce a thin and uniform electrode layer and is particularly suitable for large-scale production.

[0224] In some cases, the positive electrode 1130 can be manufactured using cryogenic casting. This process involves freezing an electrode material slurry and then sublimating the ice to form a porous structure. The resulting porous electrode can then be sintered and adhered to the current collector 1160.

[0225] For some applications, the positive electrode 1130 can be prepared using a sol-gel process. This method involves forming a colloidal suspension (sol) and then transforming it into a gel-like network containing the positive electrode active material and other components. The gel can be applied to the current collector 1160 and then heat-treated to form the final electrode structure.

[0226] Method for applying positive electrode slurry

[0227] The application method of the slurry for the positive electrode 1130 may include using methods selected from slot die coating, gravure coating, spin coating, spray coating, roller coating, curtain coating, extrusion, casting, screen printing, inkjet printing, spray printing, gravure printing, thermal transfer printing, letterpress printing, intaglio printing, offset printing, and combinations thereof. In some embodiments, the positive electrode 1130 may be manufactured using dual-layer slot die coating (DLD) technology. This method involves simultaneously coating two different electrode materials onto the current collector 1160 in a single process. The DLD process can generate a gradient structure within the electrode, thereby simultaneously optimizing the electrochemical and mechanical properties of the positive electrode. Furthermore, this technology may include a functional intermediate layer or protective coating as part of the electrode manufacturing process, thereby improving overall battery performance and lifespan.

[0228] Solvents used in positive electrode slurries

[0229] Solvents used to form the positive electrode 1130 may include water and / or organic solvents such as N-methylpyrrolidone (NMP), dimethylformamide (DMF), acetone, dimethylacetamide, dimethyl sulfoxide (DMSO), isopropanol, and combinations thereof. Considering slurry coating thickness, productivity, and combinations thereof, a sufficient amount of solvent may be used to dissolve and disperse the electrode components (e.g., positive electrode active material, binder, and conductive material). Other solvents that may be used include ethanol, methanol, propanol, butanol, ethyl acetate, methyl ethyl ketone, tetrahydrofuran, diethyl ether, and toluene. In some aspects of this disclosure, the positive electrode 1130 may be prepared using solvent-free methods, such as dry powder processing or melt extrusion, which eliminates the need for liquid solvents and can provide environmental benefits and cost advantages, but this disclosure is not limited thereto.

[0230] Dispersant for cathode slurries

[0231] The dispersant forming the positive electrode 1130 may include aqueous dispersants and / or organic dispersants, such as N-methyl-2-pyrrolidone. Other possible dispersants may include polyvinylpyrrolidone (PVP), carboxymethyl cellulose (CMC), sodium dodecyl sulfate (SDS), Triton X-100, polyethylene glycol (PEG), polyacrylic acid (PAA), and various surfactants, such as polysorbate or poloxamer, but this disclosure is not limited thereto.

[0232] Drying technology for the positive electrode

[0233] The slurry of the positive electrode 1130 can be dried by radiant heat, electron beams (E-beams), gamma rays, or UV (G-line, H-line, I-line) or combinations thereof, thereby evaporating the solvent. For example, the slurry can be vacuum dried at room temperature. Although the solvent is removed by evaporation in the drying step, other components are retained without evaporation, thus forming the positive electrode 1130. In addition to the drying techniques mentioned, other methods can be used to dry the positive electrode 1130, such as infrared (IR) drying, microwave drying, or freeze drying. In some embodiments, a combination of multiple drying techniques can be used, such as using convection heating followed by vacuum drying, to optimize the drying process and ensure complete solvent removal while maintaining the integrity of the electrode structure, but this disclosure is not limited thereto.

[0234] Negative electrode overview

[0235] The negative electrode 1120 corresponds to a polarity (e.g., negative) of the solid-state battery 1101, which differs from the polarity of the positive electrode 1130. The negative electrode 1120 is configured to act as a negative electrode during the discharge of the solid-state battery 1101. The negative electrode 1120 facilitates lithium-ion diffusion between the current collector 1110 and the solid electrolyte layer 106. The negative electrode 1120 is electrically connected to the current collector 1110. In several embodiments, the negative electrode 1120 is formed above and in direct contact with the current collector 1110. In some embodiments, as described above, the solid-state battery 1101 can utilize an anode-less system. In such a configuration, the negative electrode 1120 can be omitted, and lithium metal can be directly deposited onto the current collector 1110 during charging. This approach can potentially increase the energy density of the battery by eliminating the need for a separate negative electrode material, while also reducing the overall thickness of the battery structure.

[0236] Materials for the negative electrode

[0237] The negative electrode 1120 is capable of reversibly inserting and deintercalating lithium ions. For example, the negative electrode 1120 may include a negative electrode active material, a binder, etc., or a combination thereof. Optionally, the negative electrode 1120 may also include additives, such as oxidation stabilizers (e.g., butylated hydroxyanisole, butylated hydroxytoluene, propyl gallate, tert-butylhydroquinone), reduction stabilizers (e.g., ascorbic acid, sodium sulfite, isoascorbic acid, sodium metabisulfite), flame retardants (e.g., aluminum hydroxide, magnesium hydroxide, ammonium polyphosphate, melamine cyanurate), heat or light stabilizers (e.g., phenolic compounds, phosphites, hindered amine light stabilizers, UV absorbers such as benzophenone or benzotriazole), antifogging agents (e.g., polyethylene glycol, silica nanoparticles, glycerol, sorbitol), thickeners (e.g., carboxymethyl cellulose, xanthan gum), etc., or combinations thereof. In addition, conductive additives such as carbon black, graphene, or carbon nanotubes can be included to enhance conductivity, while adhesive modifiers such as styrene-butadiene rubber or polyacrylic acid can improve adhesion and mechanical stability. Functional additives, such as fluoroethylene carbonate or vinylene carbonate, can also be added to promote the formation of a stable solid electrolyte interface layer on the negative electrode surface, but this disclosure is not limited thereto.

[0238] Materials for negative electrode active materials

[0239] The negative electrode active material is made of or includes various materials, such as alkali metals, alkaline earth metals, group 3B metals, transition metals, quasi-metals, their alloys, conductive carbon, etc., or combinations thereof, but is not limited thereto. In many embodiments, the negative electrode active material may include silicon, silicon alloys, lithium, lithium alloys, conductive carbon, or combinations thereof, but is not limited thereto. In many embodiments, the lithium alloy is made of or contains the following: a lithium alloy comprising silicon, chlorine, or a combination thereof. The negative electrode active material may include: carbon-based materials, such as artificial graphite, natural graphite, graphitized carbon fibers, amorphous carbon, etc.; metallic materials capable of alloying with lithium, such as Si, Al, Sn, Pb, Zn, Bi, In, Mg, Ga, Cd, Si alloys, Sn alloys, Al alloys, etc.; and metal oxides capable of doping and dedoping lithium ions, such as SiO2. x(0 < x < 2), SnO2, vanadium oxides, or lithium vanadium oxides; and composites comprising a metallic material and a carbon-based material, such as a Si-C composite or a Sn-C composite. A lithium metal thin film can be used as the negative electrode active material. The carbon-based material can include low-crystalline carbon, high-crystalline carbon, etc. or a combination thereof. Representative examples of low-crystalline carbon are soft carbon or hard carbon, and representative examples of high-crystalline carbon are high-temperature calcined carbon, such as amorphous, plate-like, flaky, spherical, or fibrous natural graphite or artificial graphite, kish graphite, pyrolytic carbon, mesophase pitch-based carbon fiber, mesocarbon microbeads, mesophase pitch, coke derived from petroleum or coal tar pitch, etc., or a combination thereof. In addition to the above materials, the negative electrode active material can also include titanium-based compounds that can provide excellent cycle stability and high rate performance, such as lithium titanate (Li4Ti5O 12 ) or titanium dioxide (TiO2). Other possible materials can include transition metal oxides that can provide a relatively high theoretical capacity, such as molybdenum oxide (MoOx), iron oxide (FeOx), or nickel oxide (NiOx). In some cases, composite materials combining different active materials, such as a silicon-graphite composite or a tin-carbon composite, can be used to take advantage of the benefits of multiple materials while mitigating their respective limitations, but aspects of the present disclosure are not limited thereto.

[0240] Dendrite formation

[0241] When the negative electrode 1120 is made of lithium or a lithium alloy, or contains lithium or a lithium alloy, dendrites will form on the negative electrode 1120. Dendrites are metallic lithium structures formed when excess lithium ions accumulate on the surface of the negative electrode 1120. The formed dendrites can damage the solid electrolyte layer 106, reduce the battery capacity of the solid-state battery 1101, and / or otherwise cause undesirable performance of the solid-state battery 1101. Dendrite formation is a major challenge in lithium-based batteries because these structures can grow through the electrolyte, which may then lead to short circuits and safety hazards. The growth rate and morphology of dendrites can be affected by factors such as current density, temperature, and electrolyte-electrode interface properties.

[0242] In terms of mitigating dendrite formation, solid electrolytes have several advantages over liquid electrolytes. The mechanical strength of solid electrolytes can help inhibit dendrite growth by providing a physical barrier to the penetration of lithium metal. In addition, the uniform ion distribution in solid electrolytes can promote more uniform lithium deposition, thereby reducing the likelihood of local dendrite nucleation. Some solid electrolytes can also form a stable interface with the lithium metal negative electrode, further inhibiting dendrite formation. However, it should be noted that although solid electrolytes can significantly reduce the risk of dendrite growth, they cannot completely eliminate the risk of dendrite growth, and ongoing research aims to develop advanced solid electrolyte materials with enhanced dendrite inhibition capabilities.

[0243] Properties of negative electrode active materials

[0244] The negative electrode active material can be in particulate form or in a continuous, monolithic form (e.g., a thin film or sheet). In embodiments where the negative electrode active material is in particulate form, the negative electrode active material may include the following particle sizes: 10 nm, 20 nm, 30 nm, 50 nm, 70 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 1000 nm, 10 μm, 20 μm, 30 μm, 50 μm, 70 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, or 1000 μm. In several embodiments, the particle size of the negative electrode active material may be within a range selected from the two numbers listed in the preceding sentence, for example, between 10 nm and 1000 μm, but this disclosure is not limited thereto.

[0245] The amount of negative electrode active material in the negative electrode

[0246] The amount of negative electrode active material in solid-state battery 1101 affects the charge / discharge capacity of solid-state battery 1101. To manufacture a high-capacity negative electrode 1120, a high level of negative electrode active material can be included in the negative electrode 1120. For example, the negative electrode 1120 may contain approximately or greater than 70 wt%, 80 wt%, 90 wt%, 95 wt%, 98 wt%, 99 wt%, or 100 wt% of negative electrode active material based on the total weight of the negative electrode 1120. In various embodiments, the negative electrode active material in the negative electrode 1120 may be within a range selected from the two figures listed in the preceding sentence, for example, between 70 wt% and 100 wt%, but aspects of this disclosure are not limited thereto.

[0247] Materials of negative electrode adhesive

[0248] Adhesives can include various types of adhesive polymers, such as polyvinylidene fluoride-hexafluoropropylene copolymer (PVdF-co-HFP), polyvinylidene fluoride, polyacrylonitrile, polymethyl methacrylate, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, polyacrylate, ethylene-propylene-diene polymer (EPDM), sulfonated EPDM, styrene-butadiene rubber (SBR), fluororubber, polyacrylic acid and polymers whose hydrogen atoms are substituted with Li, Na or Ca, their various copolymers, or combinations thereof. In addition to the above adhesives, other adhesives suitable for the negative electrode include polyimide, polyamide-imide, polyurethane, polyethylene oxide (PEO), polyethylene-vinyl acetate copolymer (PEVA), polyvinyl acetate (PVA), alginate, chitosan, guar gum, xanthan gum, carrageenan, pectin, gelatin, lignin, and various water-soluble polymers or their derivatives. In some cases, conductive polymers such as polypyrrole, polyaniline, or poly(3,4-ethylenedioxythiophene) (PEDOT) can also be used as binders to simultaneously improve adhesion and conductivity within the negative electrode, but this disclosure is not limited thereto.

[0249] Amount of binder in the negative electrode

[0250] The negative electrode 1120 may include 0%, 1%, 2%, 5%, 10%, 15%, 20%, 25%, or 30% by weight of an adhesive based on the total weight of the negative electrode 1120. In various embodiments, the adhesive in the negative electrode 1120 may be within a range selected from the two figures listed in the preceding sentence, for example, between 0% and 30% by weight, but aspects of this disclosure are not limited thereto.

[0251] Thickness of the negative electrode

[0252] The negative electrode 1120 can be 10 μm, 20 μm, 30 μm, 50 μm, 60 μm, 70 μm, or 100 μm thick. In various embodiments, the thickness t4 of the negative electrode 1120 can be within a range selected from the two numbers listed in the preceding sentence, for example, between 10 μm and 100 μm, or between 10 μm and 20 μm, but this disclosure is not limited thereto.

[0253] Porosity of the negative electrode

[0254] The porosity of the negative electrode 1120 can be 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, or 18% of the total volume of the negative electrode 1120. In various embodiments, the porosity of the negative electrode 1120 can be within a range selected from the two numbers listed in the preceding sentence, for example, between 0% and 18%, but this disclosure is not limited thereto.

[0255] Lithium-ion diffusion rate of the negative electrode

[0256] The negative electrode 1120 can include 1 x 10 -14 cm 2 / s, 1 x 10 -13 cm 2 / s, 1 x 10 -12 cm 2 / s, 1 x 10 -11 cm 2 / s, 1 x 10 -10 cm 2 / s, 1 x 10 -9 cm 2 / s, 1 x 10 -8 cm 2 / s or 1 x 10 -7 cm 2 The lithium-ion diffusion rate is 1 / s. In several embodiments, the lithium-ion diffusion rate of the negative electrode 1120 can be within a range selected from the two numbers listed in the previous sentence, for example, 1 x 10⁻⁶. -14 cm 2 / s to 1 x 10 -7 cm 2 / s, but this disclosure is not limited thereto.

[0257] Negative current collector

[0258] The current collector 1110 collects the electrical energy generated by the negative electrode 1120 and supports the negative electrode 1120. The material of the current collector 1110 is not particularly limited, as long as it allows the negative electrode 1120 to adhere, has suitable conductivity, and does not cause significant chemical changes in the corresponding solid-state battery 1101 within the voltage range of the solid-state battery 1101. For example, the current collector 1110 may be made of, or include, a metal or conductive carbon, but is not limited to these. The metal of the current collector 1110 may include one or more selected from the group consisting of aluminum, aluminum alloys, copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, iron, iron alloys (e.g., steel, stainless steel), silver, silver alloys, or combinations thereof, but is not limited to these.

[0259] Shape and size of negative electrode current collector

[0260] By forming fine surface irregularities on the surface of the current collector 1110, the adhesion between the negative electrode 1120 and the current collector 1110 can be improved. The current collector 1110 can have various shapes, such as a film, sheet, foil, mesh, porous body, foam, nonwoven mesh, etc., or combinations thereof, but this disclosure is not limited thereto. In addition to the shapes mentioned above, the current collector 1110 can also be configured as a honeycomb structure, perforated sheet, woven mesh or nonwoven mesh, sintered porous body or three-dimensional interconnected grid. These different shapes can be customized to optimize the surface area, mechanical strength and current collection efficiency of the current collector 1110. Furthermore, the current collector 1110 can be designed to adapt to different form factors of solid-state batteries, such as pouch cells, cylindrical cells or prismatic cells, each of which has unique advantages in terms of packaging efficiency, thermal management and overall battery performance.

[0261] Thickness of negative electrode current collector

[0262] The thickness t5 of the current collector 1110 can be 3 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 50 μm, 100 μm, 150 μm, 200 μm, 300 μm, 400 μm, or 500 μm. In various embodiments, the thickness t5 of the current collector 1110 can be within a range selected from the two numbers listed in the preceding sentence, for example, between 5 μm and 500 μm, but this disclosure is not limited thereto.

[0263] Method for manufacturing the negative electrode

[0264] The negative electrode 1120 can be obtained by various methods, such as atomic deposition, extrusion, rolling, slurry processing, or combinations thereof. For example, the negative electrode active material can be mixed with a solvent, optionally a binder and a dispersant, and stirred to form a slurry. The slurry is then applied (e.g., coated) onto the current collector 1110, and then pressed and dried to obtain the negative electrode 1120. In addition to the methods described above, a variety of other techniques can be used to manufacture the negative electrode 1120, including dry electrode processes. These alternative methods can offer advantages in terms of environmental impact, cost-effectiveness, and scalability, but the aspects of this disclosure are not limited thereto.

[0265] Dry powder coating can serve as an alternative to the slurry method. In this process, the negative electrode active material, conductive additives, and binder are mixed in a dry state and then applied directly to the current collector 1110 using electrostatic deposition or mechanical compression. This method eliminates the need for solvents, thereby reducing environmental impact and processing time.

[0266] The negative electrode 1120 can be manufactured using additive manufacturing technologies such as 3D printing. Depending on the specific material and desired electrode properties, various 3D printing methods can be employed, including fused deposition modeling (FDM), selective laser sintering (SLS), or direct-write modeling (DIW). This method allows for precise control over the electrode structure and porosity.

[0267] Electrospinning is another possible method for manufacturing the negative electrode 1120. In this process, a solution containing the negative electrode active material, conductive additives, and polymer binder is extruded through a nozzle under an electric field to form nanofibers. These fibers can be collected directly on the current collector 1110, thereby forming a highly porous electrode structure with increased surface area.

[0268] The negative electrode 1120 can be prepared using a strip casting method. This technique involves using a doctor blade to spread a slurry of electrode material onto a moving carrier film, followed by drying and calendering. The resulting electrode strip can then be laminated onto the current collector 1110.

[0269] Spray coating technology can be used to manufacture the negative electrode 1120. A fine mist of electrode slurry is sprayed onto the current collector 1110 using compressed air or ultrasonic atomization. This method can produce a thin and uniform electrode layer and is particularly suitable for large-scale production.

[0270] Cryocasting is another possible method for manufacturing the negative electrode 1120. This process involves freezing an electrode material slurry and then sublimating the ice to form a porous structure. The resulting porous electrode can then be sintered and adhered to the current collector 1110.

[0271] In some cases, a sol-gel process can be used to prepare the negative electrode 1120. This method involves forming a colloidal suspension (sol) and then transforming it into a gel-like network containing the negative electrode active material and other components. The gel can be applied to the current collector 1110 and then heat-treated to form the final electrode structure.

[0272] For specific applications, thin-film anodes can be directly fabricated on the current collector 1110 using physical vapor deposition (PVD) or chemical vapor deposition (CVD) techniques. These methods can produce highly uniform and dense electrode layers, which is particularly advantageous for certain types of solid-state batteries.

[0273] Finally, composite anode materials can be prepared using mechanical alloying and high-energy ball milling, and then pressed into electrodes or applied to current collector 1110 using one of the methods described above. This technique is particularly useful for fabricating nanostructured or amorphous anode materials with enhanced electrochemical performance.

[0274] Ball Mill Overview

[0275] Ball milling is a valuable technology for mixing and preparing materials for all-solid-state batteries. Ball milling is a mechanical technique widely used to grind powders into fine particles and mix materials in a variety of applications, including the preparation of solid-state battery components. In the context of solid-state batteries, ball milling is commonly used to mix and blend electrode materials, solid electrolytes, and other components. Exemplary ball milling apparatuses may include planetary ball mills, vertical ball mills (attritor mills), and vibratory ball mills. These apparatuses typically consist of rotating or vibrating chambers containing grinding balls made of materials such as steel, ceramics, or zirconium oxide.

[0276] homogeneous mixing

[0277] Ball milling can effectively achieve uniform mixing of different powders. This is crucial for ensuring the uniform distribution of components in electrode materials and solid electrolytes, which in turn affects the overall performance of the battery.

[0278] Reduce particle size

[0279] Ball milling can reduce the particle size of the materials involved, thereby increasing surface area and improving reactivity. Smaller particle sizes can enhance the kinetics of electrochemical reactions, thus improving battery performance.

[0280] Enhanced electrode-electrolyte interface

[0281] Ball milling can promote the formation of a well-defined interface between the electrode and the solid electrolyte. This is crucial for facilitating efficient ion transport and minimizing interfacial resistance within solid-state batteries.

[0282] Promote solid-state reaction

[0283] Ball milling can induce solid-state reactions between different components, promoting the formation of desired phases and structures in the material. This is particularly important for the synthesis of the composite electrode materials or the preparation of composite electrolyte materials presented in this paper.

[0284] Optimize conductivity

[0285] As presented herein, ball milling can be used to optimize the conductivity of electrode materials by ensuring good distribution of conductive additives (e.g., carbon or metal nanoparticles) within the composite or additive materials within the solid electrolyte.

[0286] Control form

[0287] The grinding process also affects the morphology of the material, including particle shape and size distribution. Controlling these aspects is crucial for achieving the electrochemical properties and overall performance required for solid-state batteries.

[0288] Energy considerations

[0289] Ball milling is an energy-intensive process that requires careful control of the grinding duration and speed to avoid overheating, which can lead to adverse reactions or material damage.

[0290] Application method for negative electrode slurry

[0291] The application methods for the negative electrode 1120 slurry can include using methods selected from slit-die coating, gravure coating, spin coating, spray coating, roller coating, curtain coating, extrusion, casting, screen printing, inkjet printing, spray printing, rotary gravure printing, thermal transfer printing, letterpress printing, line engraving, offset printing, and combinations thereof. In addition to the above techniques, other methods for applying the negative electrode slurry to the current collector can include doctor blade coating, dip coating, and meniscus coating. Dual-slit-die coating can also be used, allowing two different electrode materials to be applied to the current collector simultaneously in a single process. This method can generate a gradient structure within the electrode, thereby simultaneously optimizing electrochemical and mechanical properties.

[0292] Solvents used in negative electrode slurries

[0293] Solvents used to form the negative electrode 1120 may include water and / or organic solvents such as N-methylpyrrolidone (NMP), dimethylformamide (DMF), acetone, dimethylacetamide, dimethyl sulfoxide (DMSO), isopropanol, and combinations thereof. Depending on factors such as slurry coating thickness, productivity, and combinations thereof, a sufficient amount of solvent may be used to dissolve and disperse the electrode components (e.g., the negative electrode active material and the binder). Other organic solvents that may be used include ethanol, methanol, propanol, butanol, ethyl acetate, methyl ethyl ketone, tetrahydrofuran, diethyl ether, and toluene. In some embodiments, the negative electrode 1120 may be prepared using solvent-free methods, such as dry powder processing or melt extrusion, which eliminates the need for liquid solvents and can provide environmental benefits and cost advantages, but this disclosure is not limited thereto.

[0294] Dispersant for negative electrode slurry

[0295] The dispersant forming the negative electrode 1120 may include an aqueous dispersant and / or an organic dispersant, such as N-methyl-2-pyrrolidone. Other examples of aqueous dispersants may include sodium dodecyl sulfate (SDS), polyvinylpyrrolidone (PVP), and carboxymethyl cellulose (CMC), while other organic dispersants may include Triton X-100, polyethylene glycol (PEG), and various surfactants, such as polysorbate or poloxamer. In some embodiments, the negative electrode 1120 may be prepared using dispersant-free methods, such as dry powder processing or certain additive manufacturing techniques, but aspects of this disclosure are not limited thereto.

[0296] Drying technology for negative electrodes

[0297] The slurry of the negative electrode 1120 can be dried by radiant heat, electron beams (E-beams), gamma rays, or UV (G-line, H-line, I-line) or combinations thereof to evaporate the solvent. For example, the slurry can be dried under vacuum at room temperature, but this disclosure is not limited thereto. Although the solvent is removed by evaporation in the drying step, other components are not evaporated but retained, thus forming the negative electrode 1120. In addition to the drying techniques mentioned, several other methods can be used to dry the negative electrode slurry. These additional techniques can offer various advantages depending on the specific materials, production requirements, and desired electrode characteristics.

[0298] Infrared (IR) drying can be used to rapidly heat the electrode surface, promoting efficient solvent evaporation. This method is particularly effective for thin electrode coatings and allows for precise control of the drying process. Microwave drying is another option, which can volumetrically heat the electrode material, resulting in more uniform drying across the entire electrode thickness. In some cases, a combination of convection drying and microwave drying can be used to simultaneously optimize drying speed and uniformity.

[0299] Freeze-drying (also known as lyophilization) can be used for specific electrode formulations. This process involves freezing the slurry and then sublimating the solvent under vacuum conditions. Freeze-drying can help maintain the porous structure of the electrode, which is beneficial for electrolyte permeation and ion transport.

[0300] Supercritical CO2 drying is an advanced technique applicable to specialized electrode materials. This method involves replacing the solvent with liquid CO2, then bringing the liquid CO2 to a superimpossible state and releasing it. This approach can help preserve the fine nanostructures within the electrode and is particularly useful for aerogel electrodes.

[0301] In some cases, a two-step drying process can be employed. For example, an initial drying process can be carried out at a lower temperature to remove most of the solvent, followed by a high-temperature step to remove residual solvent and to initiate any desired chemical reactions within the electrode material, but this disclosure is not limited thereto.

[0302] For certain electrode formulations, ultrasonic drying can also be considered. This technique uses high-frequency sound waves to agitate solvent molecules, thereby accelerating the drying process and improving solvent removal from the porous structure within the electrode.

[0303] Overview of solid electrolyte layers

[0304] The solid electrolyte layer 106 facilitates lithium-ion diffusion between the positive electrode 1130 and the negative electrode 1120. The solid electrolyte layer 106 provides a conductive path for the movement of charge carriers between the positive electrode 1130 and the negative electrode 1120. The solid electrolyte layer 106 is electrically connected to the positive electrode 1130 and the negative electrode 1120. In several embodiments, the solid electrolyte layer 106 is formed on and in direct contact with the positive electrode 1130 or the negative electrode 1120. In several embodiments, the solid electrolyte layer 106 is in direct contact with both the positive electrode 1130 and the negative electrode 1120. In other embodiments, an additional functional layer may be disposed between the solid electrolyte layer 106 and the positive electrode 1130 and / or the negative electrode 1120.

[0305] The solid electrolyte layer can have a gradient structure, with its composition or properties varying with its thickness to optimize ion transport and interfacial compatibility. For example, the layer can have higher ionic conductivity near the electrode and higher mechanical strength in the middle, but this disclosure is not limited thereto.

[0306] In some embodiments, the solid electrolyte layer can be formed as a composite comprising ceramic and polymer components to balance mechanical properties and ionic conductivity. The ceramic component provides structural stability, while the polymer enhances flexibility and electrode contact.

[0307] Solid electrolyte layers can include engineered porosity or channels to facilitate ion transport while maintaining mechanical integrity. These can be generated using techniques such as cryocasting or templating.

[0308] In a specific configuration, the solid electrolyte layer can be applied as multiple thin sublayers with different compositions or properties, thereby enabling fine-tuning of the overall layer properties.

[0309] The interface between the solid electrolyte and the electrode can be modified through surface treatment or the addition of a buffer layer to improve adhesion and reduce interfacial resistance. This can involve plasma treatment, chemical modification, or the deposition of nanoscale interfacial layers.

[0310] In some implementations, the solid electrolyte layer may include self-healing properties, such as the addition of microcapsules containing electrolyte material that can repair small cracks or defects formed during cycling.

[0311] Solid electrolytes can be designed to have anisotropic properties, with different ionic conductivities in different directions to optimize ion transport between electrodes while minimizing unwanted side reactions.

[0312] In certain configurations, the solid electrolyte layer may include an embedded current collector or conductive network to increase charge transport and distribution within the battery structure.

[0313] Solid electrolytes can be configured to exhibit temperature-dependent characteristics, thereby optimizing performance over a wide range of operating conditions. This can involve phase change materials or compositions with different coefficients of thermal expansion.

[0314] In some implementations, the solid electrolyte layer can be designed to be pressure-sensitive, with improved electronic conductivity under moderate pressure, thereby enhancing battery performance during operation.

[0315] Materials for solid electrolyte layers

[0316] The solid electrolyte layer 106 is capable of transporting lithium ions. The material of the solid electrolyte layer 106 is not particularly limited, as long as it can adhere to adjacent layers, has suitable conductivity, and does not cause significant chemical changes in the solid-state battery 1101 within its voltage range. For example, in addition to the composite solid electrolyte materials containing additive materials and sulfide-containing solid electrolyte materials provided herein, the solid electrolyte layer 106 may also include various inorganic solid electrolytes, polymer solid electrolytes, polymer gel electrolytes, but is not limited thereto. Alternatively or additionally, the solid electrolyte layer 106 may include ceramic electrolytes, glass electrolytes, mixed organic-inorganic electrolytes, and nanostructured electrolytes, but is not limited to these categories.

[0317] Inorganic solid electrolytes

[0318] Inorganic solid electrolytes can include crystalline solid electrolytes, amorphous solid electrolytes, glass-ceramic solid electrolytes, and combinations thereof, though not limited thereto. Inorganic solid electrolytes can be sulfide-based, oxide-based, and combinations thereof. Besides sulfide-based and oxide-based inorganic solid electrolytes, other types of inorganic solid electrolytes include halide-based electrolytes, nitride-based electrolytes, and borate-based electrolytes. For example, lithium-rich anti-perovskites (LiRAPs) such as Li3OCl, Li3OBr, lithium nitride (Li3N), and lithium borohydride (LiBH4) have been studied as potential solid electrolyte materials for lithium-ion batteries, but this disclosure is not limited thereto.

[0319] Sulfide-based solid electrolytes

[0320] As provided herein, sulfide-based solid electrolytes include sulfur (S) and have the ionic conductivity of a metal belonging to Group I or Group II of the periodic table, and may include Li-PS-based glasses or Li-PS-based glass ceramics. For example, sulfide-based solid electrolytes may include lithium sulfide, silicon sulfide, germanium sulfide, and boron sulfide. Specific examples of inorganic solid electrolytes may include Li 3.833 Sn 0.833 As 0.166 S4, Li4SnS4, Li 3.25 Ge 0.25 P 0.75 S4, Li2S-P2S0, B2S3-Li2S, xLi2S-(100-x)P2S5(x=70-80), Li2S-SiS2-Li3N, Li2S-P2S5-LiI, Li2S-SiS2-LiI, Li2S-B2S3-LiI, Li3N, LISICON, LIPON (Li 3+y PO 4-x Nx ), thio-LISICON (Li 3.25 Ge 0.25 P 0.75 S4), Li2O—Al2O3—TiO2—P2O5 (LATP), Li2S—P2S5, Li2S—LiI—P2S5, Li2S—LiI—Li2O—P2S5, Li2S—LiBr—P2S5, Li2S—Li2O—P2S5 , Li2S—Li3PO4—P2S5, Li2S—P2S5—P2O5, Li2S—P2S5—SiS2, Li2S—P2S5—SnS, Li2S—P2S5—Al2S3, Li2S—GeS2, Li2S—GeS2—ZnS, Li 10 GeP2S 12 (LGPS), Li7P3S 11 , Li6PS5Cl, Li6PS5Br, Li6PS5I, Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 Li 11 Si2PS 12 And so on, or combinations thereof. In some cases, doped variants of these materials, such as Al-doped Li... 10 GeP2S 12 Alternatively, Sb-doped Li6PS5Cl can be used to further enhance ionic conductivity or stability, but this disclosure is not limited thereto.

[0321] Oxide-based solid electrolytes

[0322] Oxide-based solid electrolyte materials contain oxygen (O) and possess the ionic conductivity of metals belonging to Group I or Group II of the periodic table. Oxide-based solid electrolyte materials can include compounds selected from LLTO-based compounds, Li6La2CaTa2O, etc. 12 Li6La2ANb2O 12 (A is Ca or Sr), Li2Nd3TeSbO 12 Li3BO 2.5 N 0.5 Li9SiAlO8, LAGP-based compounds, LATP-based compounds, Li 1+x Ti 2-x Al x Si y (PO4) 3-y (0≤x≤1, 0≤y≤1), LiAl x Zr 2-x(PO4)3(0≤x≤1, 0≤y≤1), LiTi x Zr 2-x (PO4)3 (0≤x≤1, 0≤y≤1), LISICON-based compounds, LIPON-based compounds, perovskite-based compounds, NASICON-based compounds, and LLZO-based compounds or LLZO-derived compounds (e.g., Al-doped Li7La3Zr2O). 12 Ta-doped Li7La3Zr2O 12 At least one of the following groups. Lithium-rich anti-perovskites such as Li3OCl and Li3OBr have also been studied as potential oxide-based solid electrolytes. In some cases, composite oxide electrolytes combining multiple oxide materials, such as LLZO-LATP complexes, can be used to take advantage of the different oxide systems.

[0323] Polymer solid electrolyte

[0324] Polymer solid electrolytes are complexes of electrolyte salts and polymer resins, exhibiting lithium-ion conductivity. Polymer solid electrolytes may include polyether polymers, polycarbonate polymers, acrylate polymers, polysiloxane polymers, phosphazene polymers, polyethylene derivatives, epoxyalkane derivatives, phosphate polymers, polylysine, polyester sulfides, polyvinyl alcohol, polyvinylidene fluoride, polymers containing ionically dissociable groups, polyethyleneimine (PEI), polymethyl methacrylate (PMMA), polyacrylonitrile (PAN), polyethylene succinate (PES), biopolymers such as chitosan and cellulose derivatives, or combinations thereof. Solid polymer electrolytes may include polymer resins, such as branched copolymers comprising a poly(ethylene oxide) backbone and comonomers comprising amorphous polymers (e.g., PMMA, polycarbonate, polydimethylsiloxane (PDMS) and / or phosphazene), comb polymers, crosslinked polymer resins, polyethylene glycol (PEG), polypropylene oxide (PPO), polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), poly(ethylene oxide-co-propylene oxide) (PEO-PPO), polyethyleneimine (PEI), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), various block copolymers or graft copolymers comprising these materials, or combinations thereof, but aspects of this disclosure are not limited thereto.

[0325] Polymer gel electrolyte

[0326] Polymer gel electrolytes can be formed by incorporating organic electrolytes, ionic liquids, monomers, or oligomers containing organic solvents and electrolyte salts into polymer resins or combinations thereof. Polymer resins used for polymer gels may include polyether polymers, PVC polymers, PMMA polymers, polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-co-HFP), or combinations thereof. Examples of polymeric gel electrolytes suitable for solid-state batteries include polyethylene oxide (PEO), polymethyl methacrylate-co-ethyl acrylate (PMMA-EA), polyacrylonitrile-methyl methacrylate (PAN-MMA), polyvinyl acetate (PVAc), polyethylene glycol diacrylate (PEGDA), polyvinylpyrrolidone (PVP), polyethylene glycol methyl ether acrylate (PEGMEA), polyethylene glycol methyl ether methacrylate (PEGMEMA), polyionic liquid (PIL), poly(ethylene glycol-propylene glycol) (PEG-PPG), poly(vinyl alcohol-ethylene) (PVA-PE), polyacrylamide (PAM), poly(2-hydroxyethyl methacrylate) (PHEMA), poly(ethylene glycol-co-polyethylene oxide) (PEG-PEO), and polymethacrylic acid (PMAA) based gel electrolytes to optimize the electrochemical and physical properties of solid electrolytes.

[0327] Electrolyte salts

[0328] Electrolyte salts are ionizable lithium salts, and can ionize into Li. + X - Indicates. X - It can include the choice of F - Cl - ,Br - NO3 - N(CN)2 - BF4 - ClO4 - AlO4 - AlCl4 - PF6 - SbF6 - AsF6 - BF2C2O4 - BC4O8 - (CF3)2PF4 - (CF3)3PF3 - (CF3)4PF2 - (CF3)5PF - (CF3)6P - CF3SO3 - C4F9SO3 -CF3CF2SO3 - (CF3SO2)2N - (F2SO2)2N - CF3CF2(CF3)2CO - (CF3SO2)2CH - CF3(CF2)7SO3 - CF3CO2 - CH3CO2 - SCN - (CF3CF2SO2)2N - Anions from the group consisting of, etc. For example, lithium salts can be any of the following groups: LiTFSI, LiCl, LiBr, LiI, LiClO4, lithium tetrafluoroborate (LiBF4), LiB... 10 Cl 10 Lithium hexafluorophosphate (LiPF6), LiAsF6, LiSbF6, LiAlCl4, LiSCN, LiCF3CO2, LiCH3SO3, LiCF3SO3, LiN(SO2CF3)2, LiN(SO2C2F5)2, LiC4F9SO3, LiC(CF3SO2)3, (CF3SO2)2NLi, lithium chloroborate, lower aliphatic carboxylic acids, lithium 4-phenylborate imide, lithium bis(oxalate)borate (LiBOB), lithium difluoro(oxalate)borate (LiDFOB), lithium bis(fluorosulfonyl)imide (LiFSI), lithium 4,5-dicyano-2-(trifluoromethyl)imidazolium (LiTDI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), and combinations thereof. Electrolyte salts may include any combination of the salts described herein, but aspects of this disclosure are not limited thereto.

[0329] Amount of electrolyte salts

[0330] The solid electrolyte layer 106 may include 0, 50, 60, 70, 80, 100, 200, 300, or 400 parts (if present) of electrolyte salt based on the total weight of the solid electrolyte layer 106. In various embodiments, the electrolyte salt in the solid electrolyte layer 106 may be within a range selected from the two numbers listed in the preceding sentence, for example, from 0 to 400 parts, or from 60 to 400 parts, based on the total weight of the solid electrolyte layer.

[0331] ionic conductivity of solid electrolyte layer

[0332] The solid electrolyte layer 106 may include suitable reduction stability and / or ionic conductivity. Since the primary function of the solid electrolyte layer 106 is to transport lithium ions between the electrodes, it may include an ideal ionic conductivity of approximately or greater than 10. -7 S / cm, 10 -6 S / cm, 10 -5 S / cm or 10 -4 S / cm.

[0333] Thickness of solid electrolyte layer

[0334] The thickness t6 of the solid electrolyte layer 106 can be 3 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 50 μm, 70 μm, 100 μm, 150 μm, 200 μm, 300 μm, 400 μm, 500 or 1000 μm. In various embodiments, the thickness t6 of the solid electrolyte layer 106 can be within a range selected from the two numbers listed in the preceding sentence, for example, between about 5 μm and 1000 μm, between 30 μm and 100 μm, or between 30 μm and 50 μm.

[0335] semi-finished products

[0336] like Figure 24 The shown cell 1001 can be provided as a semi-finished product. In several embodiments, the cell 1001 is stored, transported, and / or delivered to distributors, customers, etc., completing the manufacture of a battery assembly or product including the cell 1001. In other embodiments, the cell 1001 is a finished battery assembly or product.

[0337] Sealed battery

[0338] The casing 1112 of a solid-state battery can be sealed to complete the manufacture of the solid-state battery 1101, enabling it to function as a battery. The sealing process can involve various techniques to ensure that internal components are protected from external environmental factors and to maintain the integrity of the battery structure. For example, the casing 1112 can be hermetically sealed using methods such as laser welding, ultrasonic welding, or adhesive bonding, but this disclosure is not limited to these methods. In some cases, the sealing process may also include introducing a protective atmosphere or removing air to create a vacuum within the casing. This sealing step helps prevent moisture intrusion, which can degrade the performance of the sulfide-based solid electrolyte. Furthermore, the sealing process can incorporate safety features such as pressure relief mechanisms to manage any potential gas buildup during battery operation. Once properly sealed, the solid-state battery 1101 can undergo final quality control checks, which may include electrical testing, leak detection, and visual inspection. After these checks, the solid-state battery 1101 can be packaged and sold as a finished product for integration into various electronic devices, electric vehicles, energy storage systems, etc.

[0339] Battery configuration

[0340] The solid-state battery 1101 is available in a variety of configurations to suit different application and device requirements. In some cases, the battery can be manufactured in a cylindrical shape, which can be advantageous for certain types of portable electronic devices or vehicle applications. Alternatively, the solid-state battery 1101 can be manufactured in a prismatic shape, which allows for more efficient space utilization in devices with rectangular form factors. In other cases, a pouch form can be adopted, providing shape flexibility and reducing the overall battery weight. The pouch form is particularly suitable for solid-state batteries because it is easier to apply and control uniform pressure within the battery. The choice of configuration can depend on various factors such as intended use, space constraints, thermal management requirements, and manufacturing considerations. In some implementations, hybrid or custom configurations combining elements of different forms can be used to meet specific design requirements. The diversity of battery form factors allows solid-state batteries to be integrated into a wide range of products, from small wearable devices to large energy storage systems.

[0341] Voltage

[0342] The solid-state battery 1101 is configured to output a voltage of 1V, 2V, 3V, 4V, 5V, 6V, 10V, 12V, 20V, 24V, 30V, 40V, 48V, 50V, 60V, 70V, 80V, 90V, 96V, 100V, 200V, 300V, 400V, or 500V DC. In various embodiments, the output voltage of the solid-state battery 1101 can be within a range selected from the two numbers listed in the preceding sentence, for example, between 1V DC and 500V DC.

[0343] capacity

[0344] Solid-state battery 1101 is configured to have a specific capacity of approximately or greater than 100 mAh / g, 110 mAh / g, 120 mAh / g, 130 mAh / g, 140 mAh / g, 150 mAh / g, 160 mAh / g, 170 mAh / g, 180 mAh / g, 190 mAh / g, 200 mAh / g, or 300 mAh / g. In several embodiments, solid-state battery 1101 may have a capacity selected from two of the numbers listed in the preceding sentence, for example, between 100 mAh / g and 300 mAh / g.

[0345] Volume expansion calculation

[0346] The solid-state battery 1101 may include an ideal volumetric expansion rate. The volumetric expansion rate can be calculated as the increase in thickness after the first charge-discharge cycle relative to the initial thickness. The volumetric expansion rate is the proportion of the increase in thickness of a particular element after the first charge-discharge cycle relative to the change in initial thickness. The first charge-discharge cycle is performed by charging the battery at 0.1 C under CC-CV and cutting off at 4.25 V to 4.4 V and 0.02 C, and then discharging the battery at 0.1 CCC and cutting off at 3 V. The volumetric expansion rate is calculated using Equation 1 below, where A may represent the thickness before charge-discharge, and B may represent the thickness after charge-discharge. The thickness can be measured using a Mauser micrometer or a scanning electron microscope (SEM). Equation 1: Volume expansion rate = [( BA ) / A ]×100 C ratio As used herein, the C-rate refers to the rate at which a battery discharges relative to its maximum capacity. For example, a 1C rate means that the discharge current will discharge the entire battery in one hour. That is, for a battery with a capacity of 20 ampere-hours, the 1C discharge current would be 20 amperes, but this disclosure is not limited to this.

[0347] Other example methods for measuring and calculating the volume expansion rate of solid-state batteries include volume expansion measurements (e.g., gas gravity method), in-situ expansion method, X-ray tomography, strain gauge measurements, optical methods (e.g., digital image correlation or laser interferometry), pressure-based methods, and electrochemical strain microscopy.

[0348] Although several embodiments have been provided above, those skilled in the art can, with reference to this specification and the accompanying drawings, appropriately modify and practice any aspect of this disclosure by omitting, altering or substituting all or part of the components of this disclosure, or by adding other components, without departing from the technical spirit of this disclosure.

[0349] The terms and expressions used herein should be interpreted broadly and not restrictively. As used herein, the word "comprising" does not exclude the presence or addition of one or more other components besides those described.

[0350] As used in this article, unless the context clearly indicates otherwise, the singular form includes the plural form.

[0351] The various example aspects described in this specification can be combined with each other, and unless they contradict each other, what is described in a particular aspect can be equally applied to the other aspects, even if not described in the other aspects.

[0352] Although the features of this disclosure have been described above, it will be apparent that they can be changed in a variety of ways. These changes should not be considered as departing from the spirit and scope of this disclosure, and it will be apparent to those skilled in the art that all such modifications are intended to be included within the scope of the following claims.

Claims

1. A method for controlling the cycle pressure of a secondary battery, the method comprising: A secondary battery is assembled by stacking the positive electrode, separator, and negative electrode in sequence. The secondary battery is activated by applying a pressure of less than 5 MPa. and The secondary battery is cycled by applying a pressure of less than 5 MPa.

2. The method according to claim 1, wherein, The secondary battery is cycled at a pressure of 3 MPa.

3. The method according to claim 1, wherein, The secondary battery is cycled under a pressure of at least 2 MPa.

4. The method according to claim 1, wherein, The activation and recycling of the secondary battery are carried out using an isostatic bag-type cell holder (IPCH), which is configured to apply isostatic pressure to the secondary battery.

5. The method according to claim 4, wherein, The isostatic pressure in the IPCH is generated by compressed air.

6. The method according to claim 4, wherein, The IPCH includes: Cylindrical shell; A fluid that fills the interior of the housing to pressurize the secondary battery cell during at least one period of charging and discharging of the secondary battery; The wires connected to the secondary battery; and A window is located on the container wall of the cylindrical shell, allowing observation of the secondary battery.

7. The method according to claim 1, wherein, The secondary battery is a lithium secondary battery.

8. The method according to claim 1, wherein, The diaphragm includes a solid electrolyte (SSE).

9. The method according to claim 1, wherein, The secondary battery is encapsulated in a pouch-type cell.

10. The method according to claim 9, wherein, The secondary battery is an all-solid-state battery (AASB).

11. The method according to claim 1, wherein, The positive electrode includes LiNi. 0.8 Co 0.1 Mn 0.1 O2 (NCM811).

12. The method according to claim 1, wherein, The diaphragm contains Li6PS5Cl.

13. The method according to claim 1, wherein, The negative electrode contains Si.

14. The method of claim 1, further comprising applying a manufacturing pressure of 300 MPa to 500 MPa to the assembled secondary battery.

15. The method according to claim 1, wherein, The cycle is performed at room temperature.

16. The method according to claim 1, wherein, The cycle is repeated 30 to 100 times.

17. A method for controlling the cycle pressure of a secondary battery, the method comprising: Manufacturing secondary batteries under pressures ranging from 300 MPa to 500 MPa; The secondary battery is activated by applying a pressure of less than 5 MPa. as well as The secondary battery is cycled by applying a pressure of 5 MPa to 2 MPa.

18. The method according to claim 17, wherein, The activation and recycling of the secondary battery are carried out using an isostatic bag-type cell holder (IPCH), which is configured to apply isostatic pressure to the secondary battery.

19. The method according to claim 18, wherein, The IPCH includes at least one of aluminum (Al), stainless steel (SUS), titanium (Ti), nickel (Ni), iron (Fe), and copper (Cu).

20. The method according to claim 18, wherein, The IPCH includes one of 304 stainless steel, 7075 Al alloy, or Ti-6Al-4V.

Images