Electrolyte composition for secondary battery comprising quaternary ammonium compound

Abstract

Disclosed are an electrolyte composition, a secondary battery including the electrolyte composition, and a method of preparing a secondary battery. The electrolyte composition includes an electrolyte compound, a quaternary ammonium compound including a fluoride, and a solvent.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 683,964, filed August 16, 2024. The contents of the earlier application are incorporated herein by reference in their entirety. Technical Field

[0003] This invention relates to an electrolyte composition, a secondary battery comprising the electrolyte composition, and a method for preparing the secondary battery. In particular, this invention relates to an electrolyte composition comprising an electrolyte compound, a fluorinated quaternary ammonium compound, and a solvent. Background Technology

[0004] The electrification of transportation continues, with the widespread adoption of electric vehicles (EVs) and the emergence of urban air mobility (UAM) vehicles. Simultaneously, particularly in the residential and industrial sectors, there is a growing demand for stationary energy storage systems powered by solar and wind turbines. This shift is partly driven by the urgent need to mitigate the adverse environmental and climate impacts associated with conventional internal combustion engines and other non-renewable power generation methods. Therefore, the development of battery technologies with high energy density, while also ensuring enhanced safety, has become essential.

[0005] Lithium-ion batteries are crucial for the development of electrified transportation and energy storage systems, and have already had a significant and positive impact on efforts to promote green energy and mitigate climate change. While this conventional lithium-ion battery outperforms many other energy sources, lithium-ion batteries, especially liquid lithium-ion batteries, also have certain limitations. For example, various safety mechanisms are critical for limiting the voltage and internal pressure of lithium-ion batteries, but in some cases, these safety features often lead to increased weight and performance limitations. Furthermore, lithium-ion batteries are prone to aging, resulting in capacity loss and eventual failure after several years of use.

[0006] Recently, an increasing number of studies have explored the application of modified solvent structures in lithium-ion battery electrolytes. Quaternary ammonium compounds have been identified as functional additives in electrolytes. However, this field remains largely unexplored. Most conventional research focuses on the role of quaternary ammonium compounds themselves, but systematic studies evaluating the electrochemical performance of various electrolytes in lithium-ion batteries are still lacking. Moreover, despite progress, electrolyte systems with modified solvent structures exhibit poor ionic conductivity, manufacturing complexity, and high associated costs, limiting their practicality in commercial rechargeable batteries.

[0007] There remains a need to develop new electrolyte compositions to enhance Li reversibility and enable high-voltage secondary battery operation, while addressing practical concerns regarding energy density, cycle life, and cost. Therefore, ongoing efforts are underway to develop electrolytes that offer improved battery performance and stability compared to conventional lithium-ion batteries. Summary of the Invention

[0008] By using electrolyte compositions comprising quaternary ammonium compounds, such as fluorinated quaternary ammonium compounds (e.g., tetrabutylammonium tetrafluoroborate) as electrolyte functional additives, the aspects disclosed herein can solve various problems associated with conventional lithium-ion batteries. In particular, tetrabutylammonium tetrafluoroborate (TBATFB) comprises a bulky tetrabutylammonium cation (TBA). + ) and tetrafluoroborate anion (TBA) - Without being bound by theory, it is believed that when added to the electrolyte, the bulky tetrabutylammonium cation and tetrafluoroborate anion work synergistically to suppress dendrite growth, enhance interfacial stability, and improve cycle life and efficiency. The electrolyte composition was found to form a stable passivation film or interface without specifically modifying the electrolyte solvation structure. It is believed that the bulky tetrabutylammonium cation suppresses dendrite growth by regulating the Li flux, while the tetrafluoroborate anion fluorinates the anode without altering its metallic lattice structure. This synergistic effect results in dense and uniform electrodeposition, characterized by high reversibility facilitated by a stable solid electrolyte interface (SEI). The enhanced SEI interface also enables compatibility with 4-V cathodes, overcoming the thermodynamic limitations of conventional ether electrolytes dominated by solvent-separated ion pairs (SSIP).

[0009] The inventors have discovered that by controlling the content of constituent elements in the electrolyte composition and optimizing the component concentration by adjusting the concentration of quaternary ammonium compounds, electrolyte compatibility between the electrolyte composition and the anode can be reliably and efficiently achieved. In this way, electrolyte compositions can be specifically designed to optimize Li reversibility and ion transport performance, while enhancing the cycle stability of high-energy secondary batteries by integrating dendrite and corrosion inhibition mechanisms. Furthermore, compared to other conventional electrolytes, the electrolyte compositions exhibit significant economic advantages in all aspects, while providing comparable electrochemical performance and improving the stability of the anode and cathode interface.

[0010] In one aspect, an electrolyte composition for a secondary battery is provided. The electrolyte composition comprises an electrolyte compound, a fluorinated quaternary ammonium compound, and a solvent.

[0011] The solvent may comprise an ether compound. The ether compound may include at least one selected from the group consisting of tetrahydrofuran (THF), ethylene carbonate (EC), diethyl ether (DEE), 1,3-dioxolane (DOL), 1,2-dimethoxyethane (DME), dicyclohexyl ether, tetraethylene glycol dimethyl ether (TEGDME), 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (TTTE), fluorinated 1,6-dimethoxyhexane (FDMH), 1,2-bis(2,2-difluoroethoxy)-ethane (F4DEE), 2-methyltetrahydrofuran, dimethyltetrahydrofuran, dimethoxytetrahydrofuran, ethoxytetrahydrofuran, dihydropyran, tetrahydropyran, furan, and 2-methylfuran. The ether compound may include tetrahydrofuran (THF).

[0012] The electrolyte compound may include at least one selected from the group consisting of lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LTFSI), LiPF6, LiAsF6, LiBF4, LiCF3SO3, and LiClO4. The electrolyte compound may contain lithium bis(fluorosulfonyl)imide (LTFSI).

[0013] Fluorinated quaternary ammonium compounds may include tetrabutylammonium tetrafluoroborate (TBATFB).

[0014] Electrolyte compounds and fluorinated quaternary ammonium compounds may be included in the electrolyte composition in a molar ratio of 10:0.01 to 0.1:5.

[0015] Electrolyte compounds and fluorinated quaternary ammonium compounds may be included in the electrolyte composition in a molar ratio of 1:0.1 to 1:1.

[0016] On the other hand, a secondary battery comprising the above-described electrolyte composition is provided.

[0017] On the other hand, a secondary battery is provided, comprising a positive electrode, a negative electrode, and an electrolyte composition, said electrolyte composition comprising lithium bis(fluorosulfonyl)imide (LiFSI), tetrabutylammonium tetrafluoroborate (TBATFB), and tetrahydrofuran (THF).

[0018] Lithium bis(fluorosulfonyl)imide (LiFSI) and tetrabutylammonium tetrafluoroborate (TBATFB) can be included in the electrolyte composition in a molar ratio of 1:0.1 to 1:1.

[0019] The secondary battery can have a coulombic efficiency of greater than 95% after at least 200 cycles.

[0020] The secondary battery can have a specific capacity greater than 100 mAh / g at a charge / discharge rate of C / 5 to 1C for at least 100 cycles.

[0021] The secondary battery can retain more than 90% of its capacity after at least 500 cycles at a charge / discharge rate of C / 5 to 1C.

[0022] The positive electrode can be configured to embed Li + ions or Na + ion.

[0023] On the other hand, an electric vehicle including the aforementioned secondary battery is provided.

[0024] In another aspect, a method for preparing a secondary battery is provided. The method includes: forming an electrode assembly comprising a positive electrode and a negative electrode; and injecting an electrolyte composition into the electrode assembly, the electrolyte composition comprising: an electrolyte compound, a fluorinated quaternary ammonium compound, and a solvent.

[0025] Electrolyte compounds and fluorinated quaternary ammonium compounds may be included in the electrolyte composition in a molar ratio of 10:0.01 to 0.1:5.

[0026] The electrolyte compound may include lithium bis(fluorosulfonyl)imide (LiFSI), the fluorinated quaternary ammonium compound may include tetrabutylammonium tetrafluoroborate (TBATFB), and the solvent may include tetrahydrofuran (THF).

[0027] Each aspect can also have one or more additional elements in any combination. Attached Figure Description

[0028] The accompanying drawings illustrate various aspects of the invention and, together with the detailed disclosure, serve to provide a further understanding of the technical aspects of the invention; however, the invention should not be construed as being limited to the drawings. In the drawings, the shape, size, scale, or proportion of various elements may be exaggerated for emphasis in order to illustrate the concept clearly.

[0029] Figure 1A and 1B This demonstrates the use of conventional ether electrolytes ( Figure 1A ) and the electrolyte of this disclosure ( Figure 1B A schematic diagram of the interaction between the electrolyte, the 4-V cathode, and the Li metal anode (LMA) during operation.

[0030] Figure 2 This shows that when Li is solvated + (a) No TBA when advancing towards the Li metal anode + The cation layer and (b) have TBA + Solvation of Li during cationic layer + A schematic diagram of a snapshot.

[0031] Figure 3 This is a schematic diagram showing the AIMD simulation of the solvent and salt decomposition process in (a) without TBATFB and (b) with TBATFB.

[0032] Figure 4 This shows (a) THF and (b) BF4 over a duration of 50 ps. - and (c)FSI - A schematic diagram of the AIMD simulation of the decomposition process.

[0033] Figure 5 A comparison of theoretical and experimental studies of the electrolytes of this disclosure with conventional electrolytes is shown: (a) the adsorption energy of THF for metallic Li and ions within the electrolyte. Snapshots of MD simulations obtained from (b) conventional electrolytes and (c) the electrolytes of this disclosure, and (d) their corresponding Li... + Radial distribution function. (e) Raman spectra obtained from pure THF, conventional electrolytes, and the electrolyte of the present disclosure. (f) 7 Li, (g) 19 F and (h) 17 O nuclear magnetic resonance (NMR) spectrum.

[0034] Figure 6 The BF4 calculated using density functional theory (DFT) is shown. - FSI - and TBA + The electrostatic potential of ions.

[0035] Figure 7 It shows that at 1 mAcm -2 and 1 mAhcm -2 Li plating / removal of CE in Li||Cu asymmetric cells.

[0036] Figure 8 It was shown at 0.5 mAcm -2 and 5 mAhcm -2 Li plating / removal scheme for Li||Cu asymmetric cells.

[0037] Figure 9 It shows that at 1 mAcm -2 and 1 mAhcm -2 Li plating / removal CE of Li||Cu asymmetric cells using high-concentration electrolyte (3MLiFSI in THF).

[0038] Figure 10 It shows that at 1 mAcm -2 Nucleation overpotential curves of different electrolytes at different current densities.

[0039] Figure 11 The measured values ​​of ionic conductivity for different electrolytes are shown.

[0040] Figure 12 The viscosity of different electrolytes as a function of TBATFB concentration (in a 1M LiFSI THF solution) is shown.

[0041] Figure 13 The Nyquist plots of the Li||Li symmetric cell before and after 10mV polarization are shown.

[0042] Figure 14 The steady-state current measurement results of a Li||Li symmetrical cell at 10mV for 2 hours are shown.

[0043] Figure 15 This shows the effect at 0V (relative to Li / Li). + The passivation leakage current measurement results of Li||Cu cells after 10 hours of continuous operation.

[0044] Figure 16 It was shown at 0.5 mVs -1 At scan rates of -0.2 and 0.2 V (relative to Li / Li), + Tafel plot of Li||Li symmetrical cell measured between )

[0045] Figure 17 The overpotentials for constant current charge / discharge cycles at low currents from 20 to 100 μA are shown.

[0046] Figure 18 Voltage curves for constant current charging / discharging at low currents from 20 to 100 μA are shown.

[0047] Figure 19 A comprehensive graph is shown to determine the optimal additive concentration by comparing the following: exchange current density, passivation current, coulombic efficiency, ionic conductivity, and Li. + Transfer number and nucleation overpotential.

[0048] Figure 20 Raman spectra of pure THF, CEE, ACE, and a high-concentration electrolyte (HCE, 3M LiFSI in THF) are shown. HCE was added to show free FSI. - / THF and coordinating FSI - Significant differences between / THF.

[0049] Figure 21 The electrochemical performance, stability, and characterization of LMA are shown. (a) At 3 mAcm -2 and 3 mAhcm -2(a) Ceiling and peeling of Li-plated / coated cells in Li||Cu asymmetric cells. (b) Ceiling and peeling of cells in the second cycle under varying calendar aging times. (c) Ceiling and peeling of cells at 10 mA cm⁻¹. -2 and 4 mAhcm -2 and (d)20 mAcm -2 and 20 mAhcm -2 Cyclic stability of Li||Li symmetric cells. SEM images of the surface morphology and cross-sectional views of LMA after cycling in (e)CEE and (f)ACE are shown. (g)Li[THF] n + The energy of , where n represents the coordination number. (h) Li[THF]4 calculated using the NEB method under different reaction coordinates. + The potential energy diagram.

[0050] Figure 22 Voltage curves for the second plating and stripping of CEE (a, c, e) and ACE (b, d, f) are shown. (a, b) Cells were not rested, (c, d) Cells were rested for 1 day, or (e, f) Cells were rested for 5 days.

[0051] Figure 23 It is shown at 1 mAcm -2 and 1 mAhcm -2 Cyclic stability of Li||Li symmetric cells.

[0052] Figure 24 The EIS of a Li||Li symmetric cell is shown before and after 100 cycles. (a) CEE and (b) ACE electrolytes were used at 1 mAcm. -2 and 1 mAhcm -2 The Li||Li symmetric cell was then run for 100 cycles.

[0053] Figure 25 The chemical composition of the SEI is shown. XPS characterization of the cyclic LMA. (a) Atomic composition ratios using CEE and ACE at different sputtering times. (b) C1s, (c) F1s, (d) O1s, (e) Li1s, and (f) S2p spectra of the LMA cyclic with CEE and ACE. XPS spectra are shown in vertical columns, where each height corresponds to the depth profile result.

[0054] Figure 26 The following figures show the rate performance of the LFP cathode (a) and the corresponding voltage curves (b, c).

[0055] Figure 27 The following figures show (a) the rate performance of the LFP cathode and (b, c) the corresponding voltage curves. (d) LFP cathode at 0.8 mA / cm² -2 The loop performance is as follows.

[0056] Figure 28 The following figures show (a) the long-cycle performance and (b, c) the corresponding voltage curves of the Li||LFP cell. Conditions: with 4mAh / cm². -2 LFP cathode paired with 35 μmL MA, N / P ratio of 1.75, E / C ratio of 15 g Ah -1 .

[0057] Figure 29 The cycling performance of the Li||LFP cell under practical conditions (a) and the corresponding voltage curves (b, c) are shown. Conditions: with 4 mAh / cm³ -2 LFP cathode paired with 35 μmL MA, N / P ratio of 1.75, E / C ratio of 5 gAh -1 .

[0058] Figure 30 This was shown at 4.3V (relative to Li / Li). + Electrochemical float test was performed on Li||NCA88 cells for 20 hours.

[0059] Figure 31 The NCA88 cathode (2 mAh cm⁻¹) cycling at 1C is shown. -2 ) capacity.

[0060] Figure 32 The EIS curves of a cyclic NCA88 cathode are shown.

[0061] Figure 33 The GITT voltage-time curves of Li||NCA88 cells cycled using CEE and ACE are shown. Ohmic and non-ohmic voltage losses as a function of discharge capacity are measured from the GITT curves.

[0062] Figure 34 The differential capacitance (dQ / dV) of the Li||NCA88 cell as a function of voltage, measured between 3.0 and 4.3V, is shown. -1 vs. V).

[0063] Figure 35 Transmission electron microscopy images and Fourier transforms of NCA88 cathodes cyclic in (a) CEE and (b) ACE are shown. Scale bar 5 nm.

[0064] Figure 36 The atomic composition ratios at different sputtering times are shown when using (a) CEE and (b) ACE.

[0065] Figure 37XPS characterization of cyclic NCA88 is shown. (a) C1s and (b) O1s spectra of NCA88 cyclicated with CEE and ACE are shown in vertical columns, where each height corresponds to a depth profile result.

[0066] Figure 38 The rate performance of (a) the NCA88 cathode and the corresponding voltage curves (b, c) are shown.

[0067] Figure 39 The performance of the full cell with the designed electrolyte is shown. (a) Long-cycle performance of the Li||NCA88 cell, repeated 3 times. Conditions: 50 μmL MA with 2 mAh cm⁻¹ -2 NCA88 cathode pairing, N / P ratio of 5.0, E / C ratio of 4.0 gAh -1 (a) Cycling performance of the Li||NCA88 cell under 0.5C charge and discharge conditions. (b) Cycling performance of the Li||NCA88 cell under real-world conditions. Conditions: 35 μmL MA with 4 mAh cm⁻¹ -2 NCA88 cathode pairing, N / P ratio of 1.75, E / C ratio of 5.1 gAh -1 The cell was cycled at 0.1C charge and 1 / 3C discharge. (c) Cycling performance of the anode-free Cu||NCA-88 cell. Conditions: Cu with 2 mAhcm -2 Cathode pairing, E / C ratio is 4.0 gAh -1 (d) Comparison of LMB performance with other ether electrolytes in terms of cycle number, cycle retention, current density, and utility factor. The utility factor is defined as the product of the N / P ratio and the E / C ratio. Plotting of different electrolyte design strategies relative to electrolyte cost for (e) Li||Cu coulombic efficiency and corresponding areal capacity, and (f) comparison of Li||4-V cathode cycle number, capacity retention, and E / C ratio.

[0068] Figure 40 Voltage profiles of Li||NCA88 cells using (a) CEE and (b) ACE are shown for long-term cycling. Conditions: 50 μmL MA with 2 mAh cm⁻¹ -2 NCA88 cathode pairing, N / P ratio of 5.0, E / C ratio of 10.2 gAh -1 .

[0069] Figure 41 The CE of Li||NCA88 cycling performance is shown. Conditions: 50 μmL MA with 2 mAh cm⁻¹ -2 NCA88 cathode pairing, N / P ratio of 5.0, E / C ratio of 10.2 gAh -1 .

[0070] Figure 42The voltage polarization of the Li||NCA88 cycling performance is shown. Conditions: 50 μm LMA with 2 mAhcm -2 NCA88 cathode pairing, N / P ratio of 5.0, E / C ratio of 10.2 gAh -1 .

[0071] Figure 43 Voltage profiles for long-term cycling of Li||NCA88 cells using (a) CEE and (b) ACE are shown. Conditions: 35 μm LMA with 4 mAhcm -2 NCA88 cathode pairing, N / P ratio 1.75, E / C ratio 5.1 gAh -1 .

[0072] Figure 44 The CE (Cyclic Performance Evaluation) of Cu||NCA88 is shown. Conditions: Cu with 2 mAh / cm³. -2 NCA88 cathode pairing, E / C ratio is 5.1 gAh -1 .

[0073] Figure 45 The voltage curves showing the cycling performance of Cu||NCA88 are presented. Conditions: Cu with 2 mAh / cm³. -2 NCA88 cathode pairing, E / C ratio is 5.1 gAh -1 .

[0074] Figure 46 The ionic conductivity of the baseline, 0.1 M, 0.5 M, and 1.0 M BATFB electrolytes is shown. At 10 -1 Hz to 10 5 Electrochemical impedance spectroscopy (EIS) was measured at an open-circuit voltage with an amplitude of 10 mV within a frequency range of Hz.

[0075] Figure 47 The Nyquist plots of Li||Li symmetric cells before and after 2 hours of polarization at 10 mV are shown for (a) baseline, (b) 0.1 MTBATFB, (c) 0.5 MTBATFB, and (d) 1.0 MTBATFB electrolytes. -1 Hz to 10 5 EIS was measured within the Hz frequency range and at an open-circuit voltage with an amplitude of 10mV. Inset: Steady-state current measurement results after 2 hours of polarization at 10mV.

[0076] Figure 48 It is shown that (a) at a current density and areal capacity of 1 mAcm -2 and 1mAhcm -2(a) Coulombic efficiency of the asymmetric Li||Cu cell. (b) Coulombic efficiency of the Aurbarch scheme with a coulombic capacity of 5 mAh cm⁻¹. -2 Subsequently at 0.5 mAcm -2 and 0.5 mAhcm -2 Perform 10 cycles under the specified conditions, then perform a complete stripping process.

[0077] Figure 49 This was shown at 0.0V (relative to Li / Li). + Passivation stability test of Li||Cu asymmetric cells held at a voltage of 9 to 10 hours. (Inset: Leakage current between 9 and 10 hours of voltage holding.)

[0078] Figure 50 It was shown at 4.3V (relative to Li / Li) + ) for Li || LiNi 0.88 Co 0.09 Al 0.03 20-hour floating test of O2.

[0079] Figure 51 This shows the results under actual conditions (35 μm Li anode, 20 mg cm⁻¹). -2 The NCA-88 cathode has an N / P ratio of 1.75 and an E / C ratio of 5 gAh. -1 The area capacity and coulombic efficiency of the Li||NCA-88 full cell. Detailed Implementation

[0080] The invention will be described in detail below. It should be understood that the terms or words used in the specification and appended claims should not be construed as limited to their general or dictionary meanings, but rather are interpreted based on the principle of allowing the inventors to appropriately define terms for the best interpretation, and on the meanings and concepts corresponding to the technical aspects of the invention. Therefore, the aspects of the invention described herein and the elements shown in the drawings are merely aspects of the invention and are not intended to fully describe the technical aspects of the invention; thus, it should be understood that other equivalent substitutions and modifications may be made upon filing this application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly known to those skilled in the art. In cases where multiple definitions exist for terms herein, the definition provided herein shall prevail.

[0081] Unless otherwise specified, all percentages, parts and ratios in this invention are based on weight.

[0082] Unless otherwise indicated, the numerical parameters set forth in the following description and appended claims are approximate values ​​and may vary depending on the desired properties to be obtained according to aspects of the invention. Whenever a numerical range having a lower and upper limit is disclosed, any numerical value falling within that range and any inclusive range are specifically disclosed. In particular, each numerical range disclosed herein (in the form of “about a to about b,” or equivalently, “about a to b,” or equivalently, “about ab”) should be understood to describe every numerical value and range encompassed within a wider range of numerical values.

[0083] Although compositions and methods are described herein as “comprising” various components or steps, compositions and methods may also be described as “substantially consisting of various components and steps” or “consisting of various components and steps.” The terms “comprising” or “including” as used in this specification specify the presence of the stated element but do not exclude the presence or addition of one or more other elements unless the context clearly indicates otherwise.

[0084] The terms “about” and “substantially” are used herein in the sense of being equal to or nearly equal to the manufacturing and material tolerances inherent in the given described environment, and are intended to prevent unethical infringers from unfairly exploiting the invention. Precise or absolute figures are given to aid in understanding the invention. When used with numerical variables, the terms “about” and “approximately” generally refer to the value of that variable and all variable values ​​within experimental error (e.g., a 95% confidence interval of the mean) or within ±10% of a specified value or a wider range. Unless otherwise stated, all figures used in this specification and related claims to represent the amount, properties (e.g., molecular weight), reaction conditions, etc., of components should be understood to be modifiable by the term “about”.

[0085] When used in this specification, “A and / or B” refers to “any one or both of A or B”.

[0086] As used herein, the term “average particle size” refers to the average obtained particle size observed using a scanning electron microscope (SEM).

[0087] As used in this article, the term “average particle size” refers to the average particle size observed using SEM.

[0088] The terms “cathode” and “positive electrode” are used interchangeably in this document.

[0089] The terms “anode” and “negative electrode” are used interchangeably in this article.

[0090] Secondary batteries

[0091] This invention relates to secondary batteries comprising a positive electrode, a negative electrode, and an electrolyte composition. Specific examples of secondary batteries include any type of primary battery, secondary battery, fuel cell, solar cell, or capacitor (e.g., supercapacitor). In some aspects, the secondary battery may be a lithium-ion or sodium-ion secondary battery. Several aspects disclosed herein can be implemented in secondary batteries with different form factors or battery specifications, including, for example, in pouch cells, cylindrical cells, or prismatic cells.

[0092] In some aspects, the positive electrode includes a positive current collector and a positive active material layer on the surface of the positive current collector facing the solid electrolyte layer. The positive active material layer may be disposed on at least one side of the positive current collector or may exist as a coating on at least one side of the positive current collector. The battery may also include a separator located between the positive and negative electrodes.

[0093] In some aspects, the negative electrode may include a negative electrode current collector and a negative electrode active material layer on the surface of the negative electrode current collector. The negative electrode active material layer may be disposed on at least one side of the negative electrode current collector or exist as a coating on at least one side of the negative electrode current collector.

[0094] In some aspects, a battery may include a negative electrode containing a layer of negative electrode active material but without a current collector. The negative electrode may consist solely of a layer of negative electrode active material. The negative electrode may not include a separate current collector.

[0095] The secondary batteries in all aspects can withstand up to 1.0 mA / cm². 2 2.0 mA / cm 2 2.5 mA / cm 2 3.0 mA / cm 2 4.0 mA / cm 2 5.0 mA / cm 2 Or even 10.0 mA / cm 2 The charge-discharge cycle at the current density.

[0096] The coulombic efficiency of the secondary batteries in various aspects can be 20%, 30%, 40, 50, 100, 500, 1000, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 3000, 3500, 4000, 4500 or 5000 times after more than 10, 20, 30, 40, 500, 60%, 70%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%, 99.9% or more after more than 5000 charge cycles.

[0097] <Electrolyte Composition>

[0098] Electrolyte compositions in various aspects may include electrolyte compounds and additive compounds. Electrolyte compositions may be in liquid or solid form. In some aspects, the electrolyte composition is a liquid electrolyte, wherein at least one of the electrolyte compound and additive compound is provided in a solvent.

[0099] The presence of electrolyte compounds and additive compounds is an important feature of this disclosure. These compounds may be added to or present in the electrolyte composition in liquid or solid form, or as their respective salts.

[0100] The additive compound can be a fluorinated compound, including but not limited to fluorinated quaternary ammonium compounds. This fluorination mechanism suppresses dendrite formation and supports stable high-current and high-capacity operation. Without being bound by theory, it is believed that such additive compounds form a robust interface with enhanced charge transport kinetics, enabling compatibility with the cathode. In some respects, the fluorinated quaternary ammonium compound can be tetrabutylammonium tetrafluoroborate (TBATFB).

[0101] The additive compound may be included in the electrolyte composition in any suitable amount. For example, based on the total weight or total volume of the electrolyte composition, the content of the additive compound in the electrolyte composition may be 0.1% to 99.9%, 1% to 99%, 5% to 95%, 10% to 90%, 20% to 80%, 30% to 70%, 40% to 60%, or 45% to 55% by weight or volume.

[0102] The electrolyte compound can be any suitable electrolyte or its salt. For example, the electrolyte compound may include, but is not limited to, at least one selected from the group consisting of lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LTFSI), LiPF6, LiAsF6, LiBF4, LiCF3SO3, and / or LiClO4. In some aspects, the electrolyte compound may be lithium bis(fluorosulfonyl)imide (LiFSI).

[0103] Electrolyte compounds may be included in the electrolyte composition in any suitable amount. For example, based on the total weight or total volume of the electrolyte composition, the content of the electrolyte compound in the electrolyte composition may be 0.1% to 99.9%, 1% to 99%, 5% to 95%, 10% to 90%, 20% to 80%, 30% to 70%, 40% to 60%, or 45% to 55% by weight or volume.

[0104] The solvent can be any suitable organic or inorganic solvent. In some aspects, the solvent can be an ether solvent, including but not limited to tetrahydrofuran (THF), ethylene carbonate (EC), diethyl ether (DEE), 1,3-dioxolane (DOL), 1,2-dimethoxyethane (DME), dicyclohexyl ether, tetraethylene glycol dimethyl ether (TEGDME), 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (TTTE), fluorinated 1,6-dimethoxyhexane (FDMH), 1,2-bis(2,2-difluoroethoxy)-ethane (F4DEE), 2-methyltetrahydrofuran, dimethyltetrahydrofuran, dimethoxytetrahydrofuran, ethoxytetrahydrofuran, dihydropyran, tetrahydropyran, furan, and 2-methylfuran. In some aspects, the ether compound can be tetrahydrofuran (THF).

[0105] The relative concentrations of the electrolyte compound and the additive compound in the electrolyte composition are also an important feature of this disclosure. The electrolyte compound and the additive compound may be included in the electrolyte composition in a molar ratio of 100:0.001 to 0.01:50, 10:0.01 to 0.1:5, 5:0.5 to 1.5:0.1, or 1:0.1 to 1:1. In some aspects, the optimal relative molar concentration of the electrolyte compound and the additive compound in the electrolyte composition is 1:0.1.

[0106] By optimizing the concentrations of electrolyte and additive compounds in the electrolyte composition, the electrode-electrolyte interface can be enhanced by adding the ionic additive TBATFB to a low-concentration THF ether electrolyte. Not wanting to be bound by theory, it is believed that TFB... - Anions minimize corrosion and Li stock loss, while large-volume TBA + Cations are adsorbed onto the anode surface and can be electrodeposited uniformly and compactly.

[0107] <Current collector>

[0108] There are no particular restrictions on the positive and negative current collectors, as long as they are conductive and do not cause any chemical changes in the secondary battery. Materials used include, for example, copper, stainless steel, aluminum, nickel, titanium, sintered carbon, copper or stainless steel surface-treated with carbon, nickel, titanium, silver, etc., or aluminum-cadmium alloys. In some cases, the current collector can be copper. Furthermore, the current collector can include various forms, such as films, sheets, foils, meshes, porous materials, foams, and nonwoven fabrics with minute irregularities formed on their surfaces.

[0109] <Cathode Materials>

[0110] The cathode can be made of any suitable material, as long as it can carry suitable intercalated ions, such as Li. + and Na +. For the purposes of the present invention, lithium ions will be described. However, it should be understood that the present invention is not intended to be so limited, and sodium ions are also contemplated in addition to or as an alternative to lithium ions.

[0111] In the positive electrode, a positive electrode current collector can be used, and there is no particular limitation as long as the positive electrode current collector exhibits high conductivity and does not cause any chemical changes in the battery to which the positive electrode current collector is applied. For example, the positive electrode current collector can be made of stainless steel, aluminum, nickel, titanium, or plastic carbon. Alternatively, the positive electrode current collector can be made of aluminum or stainless steel whose surface is treated with carbon, nickel, titanium, or silver.

[0112] The positive electrode current collector is not limited to a specific type and can include those having high conductivity and not causing chemical changes in the corresponding battery, such as stainless steel, copper, aluminum, nickel, titanium, sintered carbon, or aluminum or stainless steel whose surface is treated with carbon, nickel, titanium, and silver.

[0113] Some aspects relate to the case where the positive electrode further includes a positive electrode material, a solid electrolyte, and a conductive agent. In some aspects, the positive electrode material includes lithium nickel manganese cobalt oxide (hereinafter referred to as NMC, Li-NMC, LNMC, or NCM), which is a mixed metal oxide of lithium, nickel, manganese, and cobalt, with the general formula LiNi x Mn y Co 1-x-y O2. In some aspects, the positive electrode material includes at least one of LiCoO2, LiMn2O4, LiMnO2, or LiNiO2. In some aspects, the positive electrode material contains sulfur.

[0114] In some aspects of the present invention, the positive electrode active material can include at least one of the following: lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), the formula Li 1+x Mn 2-x O4 (x is from 0 to 0.33, such as LiMn2O4), LiMnO3, LiMn2O3, lithium manganese oxides of LiMnO2, lithium copper oxide (Li2CuO2); vanadium oxides, such as LiV3O8, LiV2O4, V2O5, Cu2V2O7, nickel-site type lithium nickel oxides represented by the formula LiNi 1-x M x O2 (M = Co, Mn, Al, Cu, Fe, Mg, B, or Ga, 0 < x < 1), such as LiNi1- z (Co,Mn,Al) z O2 (0 < z < 1); lithium manganese composite oxides represented by the formula LiMn 2-x M x O4 (M = Co, Ni, Fe, Cr, Zn, or Ta, x = 0.01 to 1), such as LiMn 1.5 Ni0.5 O4 or Li2Mn3MO8 (M = Fe, Co, Ni, Cu or Zn); LiMn2O4 in which part of the Li is substituted by alkaline earth metal ions; disulfide; Fe2(MoO4)3, or lithium iron phosphate (LiFePO4). In some aspects of the present invention, the surface of all or at least part of the active material particles of the lithium iron phosphate may be coated with a carbon material to improve conductivity.

[0115] According to aspects of the present invention, the positive electrode active material may include at least one selected from the following: lithium nickel cobalt manganese oxide (for example, Li(Ni,Co,Mn)O2, LiNi 1-z (Co,Mn,Al) z O2 (0 < z < 1)), lithium iron phosphate (for example LiFePO4 / C), lithium nickel manganese spinel (for example, LiNi 0.5 Mn 1.5 O4), lithium nickel cobalt aluminum oxide (for example, Li(Ni,Co,Al)O2), lithium manganese oxide (for example, LiMn2O4) and lithium cobalt oxide (for example, LiCoO2).

[0116] According to some aspects of the present invention, the positive electrode active material may contain a lithium transition metal composite oxide, and the transition metal may contain at least one of Co, Mn, Ni or Al.

[0117] In some aspects of the present invention, the lithium transition metal composite oxide may contain at least one of the compounds represented by Formula 1 below.

[0118] [Formula 1]

[0119] Li x Ni a Co b Mn c M z O y

[0120] In Formula 1 above, 0.5 ≤ x ≤ 1.5, 0 < a ≤ 1, 0 ≤ b < 1, 0 ≤ c < 1, 0 ≤ z < 1, 1.5 < y < 5, a + b + c + z is less than or equal to 1, and M may contain at least one selected from Al, Cu, Fe, Mg and B.

[0121] In some aspects of the present invention, the positive electrode active material includes a high-Ni content positive electrode active material with a ≥ 0.5, and specific examples thereof may include LiNi 0.8 Co 0.1 Mn 0.1 O2.

[0122] In some aspects of the invention, the positive electrode conductive material may include at least one conductive material selected from the group consisting of graphite, carbon black, carbon fiber or metal fiber, metal powder, conductive whiskers, conductive metal oxide, activated carbon, or polyphenylene derivatives. More specifically, the positive electrode conductive material may be at least one conductive material selected from the group consisting of natural graphite, artificial graphite, Super-p, acetylene black, Ketjen black, channel black, furnace black, lamp black, thermal cracking carbon black, Denka black, aluminum powder, nickel powder, zinc oxide, potassium titanate, and titanium oxide.

[0123] The positive electrode current collector is not limited to a specific type and may include those that have high conductivity and do not cause chemical changes in the corresponding battery, such as stainless steel, copper, aluminum, nickel, titanium, sintered carbon, or aluminum or stainless steel with a surface treated with carbon, nickel, titanium and silver.

[0124] The positive electrode binder resin may include electrode polymers commonly used in this art. Non-limiting examples of binder resins include, but are not limited to: polyvinylidene fluoride, poly(vinylidene fluoride-co-hexafluoropropylene), poly(vinylidene fluoride-co-trichloroethylene), polymethyl methacrylate, ethylhexyl polyacrylate, butyl polyacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinyl acetate, polyethylene-co-vinyl acetate, polyethylene oxide, polyarylates, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl pullulan, cyanoethyl polyvinyl alcohol, cyanoethyl cellulose, cyanoethyl sucrose, pullulan, and carboxymethyl cellulose.

[0125] In some aspects of the invention, the solid electrolyte contained in the positive electrode may include at least one selected from polymeric solid electrolytes, oxide solid electrolytes, and sulfide-containing solid electrolytes. In some aspects of the invention, the positive electrode active material may comprise the sulfide-containing solid electrolyte described in the solid electrolyte membrane.

[0126] In some aspects of the invention, based on a 100% by weight positive electrode active material layer, the content of the positive electrode active material in the positive electrode is 50% by weight or more. Furthermore, according to aspects of the invention, based on a 100% by weight positive electrode active material layer, the content of the solid electrolyte in the positive electrode is 10% by weight to 40% by weight.

[0127] <Negative electrode>

[0128] There are no particular restrictions on the type of negative electrode. The negative electrode can include a negative electrode active material, which can be any suitable material, as long as the negative electrode can carry suitable intercalated ions from the positive electrode, such as Li already described herein. + and Na + .

[0129] In some respects, the negative electrode active material may include carbon-containing active materials, silicon-containing active materials and / or metal-containing active materials that can form alloys with lithium.

[0130] In the negative electrode, a negative electrode current collector can be used without particular restriction, as long as the negative electrode current collector exhibits high conductivity and does not cause any chemical changes in the battery in which it is used. For example, the negative electrode current collector can be made of stainless steel, aluminum, nickel, titanium, or plastic carbon. Alternatively, the negative electrode current collector can be made of aluminum or stainless steel with a surface treated with carbon, nickel, titanium, or silver.

[0131] The negative electrode current collector is not limited to a specific type and may include those that have high conductivity and do not cause chemical changes in the corresponding battery, such as stainless steel, copper, aluminum, nickel, titanium, sintered carbon, or aluminum or stainless steel with a surface treated with carbon, nickel, titanium and silver.

[0132] <Battery Manufacturing Methods>

[0133] In some aspects, secondary batteries can be prepared by forming an electrode assembly comprising a positive electrode and a negative electrode. This method may include injecting an electrolyte composition comprising an electrolyte compound, a fluorinated quaternary ammonium compound, and a solvent into the electrode assembly. The electrolyte composition comprising the electrolyte compound, the fluorinated quaternary ammonium compound, and the solvent may each be as described herein.

[0134] In this invention, a method for manufacturing a secondary battery may include mounting assembled battery cells in a housing component and then sealing the housing component by heating and pressurizing. Laminated housings, cylindrical metal containers, or prismatic metal containers made of aluminum or stainless steel may be suitably used as the housing component.

[0135] The electrode paste can be coated onto the corresponding current collector using methods such as placing the electrode paste on the current collector and uniformly dispersing it with a doctor blade, molding, comma coating, or screen printing. Alternatively, the electrode paste and current collector can be formed on separate substrates and bonded together by pressure or lamination. In this case, the concentration of the paste solution or the amount of coating can be adjusted to control the final coating thickness.

[0136] The drying process is the process of removing solvent or moisture from a slurry to dry the slurry coated on a metal current collector. The drying process can vary depending on the solvent used. For example, the drying process can be carried out in a vacuum oven at temperatures ranging from 50°C to 200°C. Drying can be performed using methods such as warm air drying, hot air drying, low-humidity air drying, vacuum drying, (far)infrared drying, or electron beam radiation. There are no particular limitations on the drying time. Typically, drying takes place within the range of 30 seconds to 24 hours.

[0137] After the drying process, a further cooling process can be carried out. During the cooling process, the material can be slowly cooled to room temperature to allow for the full formation of the recrystallized structure of the adhesive.

[0138] Furthermore, if desired, a rolling process can be performed, in which the electrode is passed through the gap between two heated rollers, thereby compressing the electrode to a desired thickness to increase its capacity density and improve adhesion between the current collector and the active material after the drying process. In this invention, there are no particular limitations on the rolling process. Known rolling processes, such as pressing, can be performed. For example, the electrode can be passed through the gap between rotating rollers, or a flat press can be used to press the electrode.

[0139] <Battery Overview>

[0140] Batteries in various aspects may include lithium-ion batteries and / or sodium-ion batteries. For the purposes of this invention, lithium-ion batteries will be described. However, it should be understood that this invention is not intended to be so limiting, and sodium-ion batteries are also considered in addition to lithium-ion batteries or as a substitute for lithium-ion batteries.

[0141] Lithium-ion batteries

[0142] Solid-state batteries can receive electrical loads for charging and discharging at various times. A solid-state battery consists of electrodes, namely a cathode and an anode, and an electrolyte that allows lithium ions to move between the electrodes. Unlike conventional liquid electrolyte batteries, solid-state batteries do not contain any flowing liquid. A circuit is formed between the electrodes to allow electricity to flow between them. During the charging process of a rechargeable lithium-ion battery, lithium ions are emitted from the cathode and inserted into the active material of the anode. As lithium ions move back and forth between the electrodes, they transfer energy.

[0143] Solid-state battery configuration

[0144] This invention provides a solid-state battery comprising a cathode, an anode, and a solid electrolyte layer between the cathode and the anode. In some aspects, the solid electrolyte can serve as both an electrolyte and a separator. Although listed as an example, solid-state batteries do not require all of these components. For example, in some configurations, such as in an anode-less system, the anode can be omitted. Alternatively, according to aspects of the invention, the anode may comprise an anode material having a metal-carbon composite, such as a silver-carbon mixture or composite, wherein silver particles are composited between amorphous carbon particles and / or crystalline carbon particles. While silver is used as an example, other metals may also be used, including, for example, tin, silicon, zinc, or combinations thereof.

[0145] Solid-state batteries may optionally include one or more additional layers, such as separators, protective layers, inhibitor layers, solid electrolyte interface layers, or combinations thereof. For example, a protective layer can be added between the electrodes and the solid electrolyte layer. This protective layer may include materials such as lithium phosphate, lithium titanate, or lithium lanthanum zirconium oxide (LLZO), which can help prevent unwanted side reactions at the electrode-electrolyte interface. The protective layer can also be used to mitigate dendrite formation, particularly on the anode side, thereby improving the overall cycle life and safety of the battery. Separators may also be included in some solid-state battery configurations. While conventional liquid electrolyte batteries often use porous polymer separators, solid-state batteries can employ thin ceramic or glass-ceramic layers as separators. These separators can provide additional mechanical support to 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. The separator can also be designed with a gradient structure, providing optimized performance for contact with the cathode and anode materials.

[0146] Battery cell configuration

[0147] Solid-state batteries can comprise a single cell. In other respects, they can comprise multiple cells, such as at least two, three, or four cells. Connecting cells in series increases the voltage of the solid-state battery, while connecting cells in parallel increases its ampere-hour capacity. In some aspects, solid-state batteries can be configured with a combination of series and parallel connections to achieve desired voltage and capacity characteristics. For example, multiple cells can be arranged in groups, with cells within each group connected in parallel to increase capacity, and then these groups are connected in series to increase voltage. This configuration, sometimes referred to as a series-parallel configuration, allows for greater flexibility in battery design and can help optimize performance for specific applications. Additionally, the number and arrangement of cells can be adjusted to meet various form factor requirements.

[0148] Cell thickness

[0149] The thickness t1 of the battery cell can be approximately 100, 150, 200, 250, 300, 400, 500, 1000 μm, 2000 μm, or 5000 μm. In some respects, the range of the thickness t1 of the battery cell can be formed by selecting any two values ​​listed in the preceding sentence, for example, approximately 100 μm to approximately 5000 μm, or approximately 100 μm to approximately 1000 μm.

[0150] Cathode Overview

[0151] The cathode is associated with one polarity (e.g., the positive electrode) of the solid-state battery. The cathode is configured as the positive electrode during the discharge process of the solid-state battery. The cathode is adapted to facilitate the diffusion of lithium ions between the current collector and the solid electrolyte layer. The cathode is electrically connected to the current collector. In some cases, the cathode is formed on and in direct contact with the current collector. In other cases, another functional layer may be disposed between the cathode and the current collector.

[0152] cathode material

[0153] The cathode can reversibly insert and deintercalate lithium ions. For example, the cathode may include one or more of cathode active materials, conductive carbon, solid electrolyte materials, binders, etc., or combinations thereof. Optionally, the cathode 102 may also contain additives, such as oxidation stabilizers, reduction stabilizers, flame retardants, heat stabilizers, antifogging agents, thickeners, etc., or combinations thereof. Examples of such additives may 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 / esters as heat stabilizers, polyethylene glycol or silica nanoparticles as antifogging agents, and carboxymethyl cellulose (CMC) or xanthan gum as thickeners.

[0154] Cathode active materials

[0155] Cathode 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 Let be any element selected from Al, Ga, In, or a combination thereof, where 0.3 ≤ a < 1.0, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.5, 0 ≤ d ≤ 0.1, and 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 Includes Mn and at least one element selected from Ni, Co, Fe, Cr, V, Cu, Zn, and Ti, M 3 Lithium manganese oxide, for example, is composed of at least one element selected from Al, Mg, and B, and A is at least one element selected from P, F, S, and N, or is a compound having one or more transition metals substituted for it; lithium manganese oxide, for example, is composed of the chemical formula Li1+h Mn 2-h Those represented by O4 (where 0≤h≤0.33), LiMnO3, LiMn2O3, LiMnO2, etc.; lithium copper oxide (Li2CuO2); vanadium oxides, such as LiV3O8, V2O5, or Cu2V2O7; and those represented by the chemical formula LiNi. 1-i M 4 i O2 (where M) 4 =Co, Mn, Al, Cu, Fe, Mg, B or Ga, 0.01≤y≤0.3) represents nickel-site lithium nickel oxides; 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 Li is partially substituted by alkaline earth metal ions; disulfides; LiFe3O4, Fe2(MoO4)3; etc.; or combinations thereof.

[0156] Besides the cathode active materials mentioned above, cathodes can also include 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 materials include lithium manganese iron phosphate (LiMn). x Fe 1-x PO4 or lithium cobalt phosphate (LiCoPO4) may also be suitable.

[0157] Cathode 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) can be used, where 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) can be used. 0.8 Co 0.1 Mn 0.1 O2) to achieve higher energy density. In some cases, the cathode active material may include a spinel structure, such as LiNi. 0.5 Mn 1.5O4 can be used, which enables high-voltage operation. Alternatively, materials with advantageous structures, such as LiFeSO4F or LiVPO4F, can be used because they have the potential for high energy density and good thermal stability.

[0158] Composite or hybrid cathode materials combining two or more active materials can also be used. For example, blends of layered oxides and spinel materials can be used to balance energy density and power performance. As another example, lithium iron phosphate can be blended with one or more of the above-mentioned cathode active materials. In some aspects, cathode active materials may include surface-modified forms of the above-mentioned compounds, wherein the surface modification is intended to improve stability, conductivity, or other performance metrics.

[0159] Cathode active materials can also include emerging types of materials, such as disordered rock salt structures (e.g., Li3N). b O4-type materials or high-entropy oxides offer a unique combination of high capacity and structural stability. In some cases, cathode active materials can be doped with dopants or substitute elements to further tune their electrochemical properties.

[0160] Particle properties of cathode active materials

[0161] The cathode active material can be in particulate form. The particle size of the cathode active material can be 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 some aspects, the particle size range of the cathode active material can be formed by selecting any two values ​​listed in the preceding sentence, for example, from about 10 nm to about 1000 μm. The gaps between the cathode active materials in the cathode can be filled with a solid electrolyte material.

[0162] Amount of cathode active material in the cathode

[0163] The amount of cathode active material in a solid-state battery affects its charge and discharge capacity. To manufacture a high-capacity cathode, a high level of cathode active material can be included. For example, based on the total weight of the cathode, the cathode may contain approximately 30, 40, 50, 60, 70, 80, 90, 95, or 98% by weight or more of cathode active material. In some aspects, the range of cathode active material in the cathode can be formed by selecting any two values ​​listed in the preceding sentence, for example, approximately 40% by weight to approximately 98% by weight.

[0164] Conductive material in cathode

[0165] There are no particular restrictions on the conductive materials used in the cathode, as long as they are conductive and do not cause any chemical changes in the corresponding solid-state battery. For example, conductive materials can 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); metal powders, such as fluorocarbons, aluminum, or nickel powder; conductive whiskers, such as zinc oxide or potassium titanate; conductive metal oxides, such as titanium oxide; conductive materials such as polyphenylene derivatives; and so on; or combinations thereof. Other conductive materials that can be used in the cathode include graphene and its derivatives, such as reduced graphene oxide (rGO) or graphene nanosheets. These two-dimensional carbon materials provide high surface area and excellent conductivity. Conductive polymers, such as polyaniline (PANI), polypyrrole (PPy), or poly(3,4-ethylenedioxythiophene) (PEDOT), can also be used to enhance the conductivity of electrodes while potentially improving their mechanical properties. In some cases, hybrid 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.

[0166] Amount of conductive material in the cathode

[0167] Based on the total weight of the cathode, the cathode comprises approximately 1 wt%, 2 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, or 30 wt% of conductive material. In some aspects, the range of conductive material in the cathode can be formed by selecting any two values ​​listed in the preceding sentence, for example, approximately 1 wt% to approximately 30 wt%.

[0168] Adhesive materials

[0169] Adhesives can include various types of adhesive polymers, such as: polyvinylidene fluoride-co-hexafluoropropylene (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 monomer (EPDM), sulfonated EPDM, styrene-butadiene rubber (SBR), fluororubber, polyacrylic acid, polymers whose hydrogen atoms are substituted with Li, Na, or Ca, various copolymers thereof, or combinations thereof. In addition to the adhesive materials mentioned above, other types of adhesive materials can also be used in cathodes to enhance their 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 bond strength. In some cases, conductive adhesives, such as poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) or polyaniline (PANI), can be used to simultaneously improve the mechanical integrity and conductivity of electrodes. Novel adhesive systems, such as self-healing polymers or supramolecular assemblies, can be incorporated to enhance the long-term stability and cycle life of the battery. Additionally, composite adhesives combining multiple polymers or incorporating inorganic nanoparticles can be used to tune the mechanical, thermal, and electrochemical properties of the electrodes. In some aspects, bio-derived or biodegradable adhesives, such as cellulose derivatives or chitosan, can be used to reduce the environmental impact of battery production and disposal.

[0170] Amount of binder in cathode

[0171] Based on the total weight of the cathode, the cathode contains approximately 1 wt%, 2 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, or 30 wt% of binder. In some respects, the range of binder in the cathode can be formed by selecting any two values ​​listed in the preceding sentence, for example, approximately 1 wt% to approximately 30 wt%.

[0172] Materials for solid electrolytes

[0173] The solid electrolyte material in the cathode can be configured separately from the materials used for the solid electrolyte layer, as discussed below. The solid electrolyte material in the cathode can be the same as or different from the materials used for the solid electrolyte layer.

[0174] Amount of solid electrolyte material in the cathode

[0175] Based on the total weight of the cathode, the cathode 102 comprises about 1 wt%, 2 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, or 30 wt% of solid electrolyte material. In some aspects, the range of amounts of solid electrolyte material in the cathode can be formed by selecting any two values ​​listed in the preceding sentence, for example, about 1 wt% to about 30 wt%.

[0176] Cathode thickness

[0177] The cathode thickness t2 can be approximately 10, 20, 50, 100, 150, 200, 250, 300, 400, 500, or 1000 μm. In some respects, the range of cathode thickness t2 can be formed by selecting any two values ​​listed in the preceding sentence, for example, approximately 10 μm to approximately 1000 μm.

[0178] Cathode porosity

[0179] Based on the total volume of the cathode, the porosity of the cathode can be approximately 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18 volume%. In some respects, the range of cathode porosity can be formed by selecting any two values ​​listed in the preceding sentence, for example, from 0 volume% to approximately 18 volume%.

[0180] Lithium-ion diffusion rate of the cathode

[0181] The lithium-ion diffusivity of the cathode can include approximately 1 × 10⁻⁶. -14 cm 2 / s, 1×10 -13 cm 2 / s, 1×10 -12 cm 2 / s, 1×10 -11 cm 2 / s, 1×10 -10 cm 2 / s, 1×10 -9 cm 2 / s, 1×10 -8 cm 2 / s or 1×10 -7 cm 2 / s. In some respects, the range of lithium-ion diffusion rate of the cathode can be formed by selecting any two values ​​listed in the previous sentence, such as 1×10 -14 cm 2 / s to approximately 1×10 -7 cm 2 / s.

[0182] Current collector at cathode

[0183] The current collector collects the electrical energy generated at the cathode and supports the cathode. The material of the current collector is not particularly limited, as long as it allows cathode adhesion, has suitable conductivity, and does not cause significant chemical changes in the corresponding solid-state battery within the voltage range of the solid-state battery. For example, the current collector 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 can include, but is not limited to, one or more of the following groups: 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, bismuth, or combinations thereof.

[0184] Shape and size of the current collector at the cathode

[0185] The adhesion between the cathode and the current collector can be increased by forming fine surface irregularities on the surface of the current collector. The current collector can have various shapes, such as films, sheets, foils, meshes, porous bodies, foams, nonwoven fabrics, etc., or combinations thereof. The current collector can also be configured into various other geometries to optimize its performance and integration with the cathode, and its dimensions can be determined according to specific shape factors (e.g., bag-shaped, cylindrical, and / or prismatic shape factors). For example, the current collector can be configured as a mesh or grid, which can provide enhanced mechanical support while maintaining a high surface area for electrode adhesion. In some aspects, the current collector can be designed with corrugated or wavy patterns, potentially increasing the contact area with the cathode material and improving overall conductivity. The current collector can also be fabricated as a perforated sheet to allow for better electrolyte permeation and ion transport. In some cases, the current collector can be formed into a three-dimensional structure, such as an interconnected fiber network or a honeycomb structure, which can enhance the structural integrity of the electrode assembly while promoting efficient current collection.

[0186] Thickness of the current collector at the cathode

[0187] The thickness t3 of the current collector can be about 3, 5, 10, 15, 20, 25, 50, 100, 150, 200, 300, 400 or 500 μm. In some respects, the range of the thickness t3 of the current collector 108 can be formed by selecting any two values ​​listed in the preceding sentence, for example, about 5 μm to about 500 μm.

[0188] Method for manufacturing cathode

[0189] Cathodes can be obtained by various methods. For example, the cathode active material can be mixed with a solvent and optionally a binder, conductive material, and dispersant and stirred to form a slurry. The slurry can then be applied (e.g., coated) onto a current collector, followed by pressing and drying to obtain a cathode.

[0190] Besides the slurry-based method described, various other techniques can be used to fabricate cathodes. For example, a dry powder coating method can be employed, in which the cathode active material, conductive additives, and binder are mixed in a dry state and then applied directly to the current collector using electrostatic deposition or mechanical compression. This method reduces environmental impact by eliminating the need for solvents.

[0191] In some cases, cathodes can be fabricated using additive manufacturing techniques such as 3D printing. This method allows for precise control over the electrode's structure and porosity, potentially enhancing its performance and energy density. Depending on the specific material and desired electrode performance, various 3D printing methods can be used, including fused deposition modeling (FDM), selective laser sintering (SLS), or direct ink writing (DIW).

[0192] Another method for manufacturing cathodes can include electrospinning. In this method, a solution containing cathode active material, conductive additives, and polymer binders is extruded through a nozzle under an electric field, resulting in the formation of nanofibers. These fibers can be directly collected on a current collector to form a highly porous electrode structure with an increased surface area.

[0193] In some respects, cathodes can be fabricated using a casting process. 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 strip can then be laminated onto a current collector.

[0194] Alternatively, the cathode can be manufactured using a spray coating technique. In this method, a fine mist of electrode slurry is sprayed onto the current collector using compressed air or ultrasonic atomization. This method allows for the production of thin, uniform electrode layers and can be particularly useful for large-scale production.

[0195] In some cases, cathodes can be manufactured using a cryogenic casting method. This method involves freezing a slurry of electrode material and then sublimating the ice to create a porous structure. The resulting porous electrode can then be sintered and attached to a current collector.

[0196] For some applications, the cathode can be prepared using the sol-gel method. This method involves forming a colloidal suspension (sol) and then transforming it into a gel-like network containing the cathode active material and other components. The gel can be applied to the current collector 108 and subsequently heat-treated to form the final electrode structure.

[0197] Cathodic paste coating method

[0198] The coating of cathode paste can include techniques selected from: slot die coating, gravure coating, spin coating, spray coating, roll coating, curtain coating, extrusion, casting, screen printing, inkjet printing, gravure printing, thermal transfer printing, Toppan printing, gravure engraving, lithography, etc., and combinations thereof. In some aspects, the cathode can be manufactured using dual-layer slot die coating (DLD) technology. This method involves simultaneously applying two different electrode material layers to the current collector in a single pass. The DLD process can allow the creation of gradient structures within the electrode, potentially optimizing the electrochemical performance and mechanical properties of the cathode. Additionally, this technology can integrate the incorporation of functional intermediate layers or protective coatings as part of the electrode manufacturing process, potentially improving overall cell performance and lifespan.

[0199] Solvents used in cathode paste

[0200] Solvents used to form the cathode may include water and / or organic solvents such as N-methylpyrrolidone (NMP), dimethylformamide (DMF), acetone, dimethylacetamide, dimethyl sulfoxide (DMSO), isopropanol, etc., or combinations thereof. Depending on the slurry coating thickness, productivity, etc., or combinations thereof, the solvent may be used in an amount sufficient to dissolve and disperse the electrode components (e.g., cathode 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 the invention, the cathode 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 and cost benefits.

[0201] Dispersant for cathode slurry

[0202] The dispersant forming the cathode 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 (e.g., polysorbate or poloxamer).

[0203] Cathode drying technology

[0204] Cathode slurries can be dried by radiative heating, electron beams (E-beams), gamma rays, or UV (G, H, I-lines) or combinations thereof to evaporate the solvent. For example, the slurry can be vacuum dried at room temperature. Although the solvent is removed by evaporation through the drying step, other components do not evaporate and remain as is to form the cathode. In addition to the drying techniques mentioned, cathodes can be dried using other methods, such as infrared (IR) drying, microwave drying, or freeze-drying. In some cases, combinations of drying techniques can be employed, 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.

[0205] Anode Overview

[0206] The anode is associated with one polarity (e.g., the negative electrode) of the solid-state battery, different from the cathode polarity. The anode is configured as the negative electrode during discharge of the solid-state battery. The anode is adapted to allow lithium ions to diffuse between the current collector and the solid electrolyte layer. The anode is electrically connected to the current collector. In some aspects, the anode is formed on and in direct contact with the current collector. In some aspects, as described above, solid-state batteries can utilize anode-less systems. In such a configuration, the anode can be omitted, and lithium metal can be deposited directly onto the current collector during charging. This approach can potentially increase the energy density of the battery by eliminating the need for a separate anode material, while also potentially reducing the overall thickness of the battery structure.

[0207] Anode material

[0208] The anode can reversibly insert and deintercalate lithium ions. For example, the anode may include an anode active material, a binder, or a combination thereof. Optionally, the anode may further include additives such as oxidation stabilizers (e.g., butylated hydroxyanisole, butylated hydroxytoluene, propyl gallate, tert-butylhydroquinone), reduction stabilizers (e.g., ascorbic acid, sodium sulfite, D-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 / esters, 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. Additionally, conductive additives, such as carbon black, graphene, or carbon nanotubes, can be incorporated 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 included to promote the formation of a stable solid electrolyte interface layer on the anode surface.

[0209] Anode active materials

[0210] The anode active material is made of or includes various materials, such as alkaline earth metals, alkaline earth metals, Group 3B metals, transition metals, metalloids, their alloys, conductive carbon, etc., or combinations thereof, but not limited thereto. In some aspects, the anode active material may include silicon, silicon alloy, lithium, lithium alloy, conductive carbon, or combinations thereof, but not limited thereto. In some aspects, the lithium alloy is made of or includes a lithium alloy containing silicon, chlorine, or a combination thereof. The anode active material may include carbon-based materials, such as artificial graphite, natural graphite, graphitized carbon fiber, amorphous carbon, etc.; metal substances capable of alloying with lithium, such as Si, Al, Sn, Pb, Zn, Bi, In, Mg, Ga, Cd, Si alloy, Sn alloy, Al alloy, etc.; metal oxides capable of doping and de-doping lithium ions, such as SiOx (0 < x < 2), SnO2, vanadium oxides, or lithium vanadium oxides; and composite materials containing the metal substance and the carbon-based material, such as Si-C composite or Sn-C composite. Lithium metal thin films can be used as the anode active material. The carbon-based materials may include low-crystalline carbon, high-crystalline carbon, etc., or combinations 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, mesophase carbon microbeads, mesophase pitch, petroleum or coal tar pitch-derived coke, etc., or combinations thereof. In addition to the materials mentioned, the anode active material may also include titanium-based compounds, such as lithium titanate (Li4Ti5O 's content seems incomplete here. There should be a number after O in the formula Li4Ti5O. 12 ) or titanium dioxide (TiO2), which can provide excellent cycle stability and high rate performance. Other potential materials may include transition metal oxides, such as molybdenum oxides (MoOx), iron oxides (FeOx), or nickel oxides (NiOx), which can provide high theoretical capacity. In some cases, composite materials combining different active materials, such as silicon-graphite composite or tin-carbon composite, can be used to utilize the advantages of multiple materials while alleviating their respective limitations.

[0211] Dendrite formation

[0212] Dendrites may form on the anode when it is made of or contains lithium or lithium alloys. Dendrites are metallic lithium structures that form when additional lithium ions accumulate on the anode surface. The formed dendrites can damage the solid electrolyte layer, reduce the battery capacity of the solid-state battery, and / or otherwise cause undesirable performance. Dendrite formation is a significant challenge in lithium-based batteries because these structures can grow through the electrolyte, potentially causing short circuits and safety hazards. The growth rate and morphology of dendrites can be influenced by factors such as current density, temperature, and the properties of the electrolyte-electrode interface.

[0213] When it comes to mitigating dendrite formation, solid electrolytes offer several advantages over liquid electrolytes. The mechanical strength of solid electrolytes helps suppress dendrite growth by providing a physical barrier to lithium metal penetration. Additionally, the uniform ion distribution in solid electrolytes promotes more uniform lithium deposition, reducing the likelihood of localized dendrite nucleation. Some solid electrolytes can also form stable interfaces with lithium metal anodes, further suppressing dendrite formation. However, it is important to note that while solid electrolytes can significantly reduce the risk of dendrite growth, they may not completely eliminate it, and ongoing research aims to develop advanced solid electrolyte materials with enhanced dendrite suppression capabilities.

[0214] Properties of Anode Active Materials

[0215] The anolyte can be particulate or continuous, single-piece (e.g., thin film or sheet). In some aspects where the anolyte is particulate, the particle size can include approximately 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, or 1000 μm. In some aspects, the particle size range of the anolyte can be formed by selecting any two values ​​listed in the preceding sentence, for example, approximately 10 nm to approximately 1000 μm.

[0216] Amount of anolyte active material in the anode

[0217] The amount of anode active material in a solid-state battery affects its charge and discharge capacity. To manufacture a high-capacity anode, a high level of anode active material can be included in the anode. For example, based on the total weight of the anode, the anode may contain approximately 70, 80, 90, 95, 98, 99% or more, or 100% by weight, of anode active material. In some aspects, the range of anode active material in the anode can be formed by selecting any two values ​​listed in the preceding sentence, for example, approximately 70% by weight to approximately 100% by weight.

[0218] Materials of binder in anode

[0219] Adhesives may include various types of adhesive polymers, such as: polyvinylidene fluoride-co-hexafluoropropylene (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 monomer (EPDM), sulfonated EPDM, styrene-butadiene rubber (SBR), fluororubber, polyacrylic acid, polymers whose hydrogen atoms are substituted with Li, Na, or Ca, various copolymers thereof, or combinations thereof. In addition to the adhesives mentioned, other suitable adhesives for anodes may include polyimides, polyamide-imides, polyurethanes, polyethylene oxide (PEO), ethylene-vinyl acetate copolymer (PEVA), polyvinyl acetate (PVA), alginates, 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 adhesives to simultaneously improve adhesion and conductivity within the anode.

[0220] Amount of binder in the anode

[0221] Based on the total weight of the anode, the anode may contain approximately 0 wt%, 1 wt%, 2 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, or 30 wt% of binder. In some respects, the range of binder in the anode can be formed by selecting any two values ​​listed in the preceding sentence, for example, approximately 0 wt% to approximately 30 wt%.

[0222] Anode thickness

[0223] The anode can be about 10, 20, 30, 50, 60, 70 or 100 μm thick. In some respects, the range of anode thickness t4 can be formed by selecting any two values ​​listed in the preceding sentence, for example, about 10 μm to about 100 μm, or about 10 μm to about 20 μm.

[0224] Anode porosity

[0225] Based on the total volume of the anode, the porosity of the anode can be approximately 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18 volume%. In some respects, the range of anode porosity can be formed by selecting any two values ​​listed in the preceding sentence, for example, from 0 volume% to approximately 18 volume%.

[0226] Lithium-ion diffusion rate of the anode

[0227] The lithium-ion diffusion rate of the anode can include approximately 1 × 10⁻⁶. -14 cm 2 / s, 1×10 -13 cm 2 / s, 1×10 -12 cm 2 / s, 1×10 -11 cm 2 / s, 1×10 -10 cm 2 / s, 1×10 -9 cm 2 / s, 1×10 -8 cm 2 / s or 1×10 -7 cm 2 / s. In some respects, the range of lithium-ion diffusion rate at the anode can be formed by selecting any two values ​​listed in the previous sentence, such as 1×10 -14 cm 2 / s to approximately 1×10 -7 cm 2 / s.

[0228] Current collector at the anode

[0229] The current collector collects the electrical energy generated at the anode and supports the anode. The material of the current collector is not particularly limited, as long as it allows anode adhesion, has suitable conductivity, and does not cause significant chemical changes in the corresponding solid-state battery within its voltage range. For example, the current collector may be made of or contain metal or conductive carbon, but is not limited to these. The metal in the current collector 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.

[0230] Shape and size of the current collector at the anode

[0231] By forming fine surface irregularities on the surface of the current collector, the adhesion between the anode and the current collector can be increased. The current collector can have various shapes, such as films, sheets, foils, meshes, porous bodies, foams, nonwoven fabrics, or combinations thereof. In addition to the shapes mentioned, the current collector can also be configured as a honeycomb structure, perforated sheets, woven or nonwoven meshes, sintered porous bodies, or three-dimensional interconnected networks. These different shapes can be tailored to optimize the surface area, mechanical strength, and current collection efficiency of the current collector. Furthermore, the current collector can be designed to accommodate different shape factors of solid-state batteries, such as pouch cells, cylindrical cells, or prismatic cells, each offering unique advantages in terms of packaging efficiency, thermal management, and overall battery performance.

[0232] Thickness of the current collector at the anode

[0233] The thickness t5 of the current collector can be about 3, 5, 10, 15, 20, 25, 50, 100, 150, 200, 300, 400 or 500 μm. In some respects, the range of the thickness t5 of the current collector can be formed by selecting any two values ​​listed in the preceding sentence, for example, about 5 μm to about 500 μm.

[0234] Method for manufacturing anodes

[0235] Anodes can be obtained by various methods, such as atomic deposition, extrusion, rolling, slurry processing, or combinations thereof. For example, the anode active material can be mixed with a solvent and optionally a binder and dispersant and stirred to form a slurry. The slurry can then be applied (e.g., coated) onto a current collector, followed by pressing and drying to obtain the anode. In addition to the methods mentioned, anodes can be manufactured using a variety of other technologies, including dry electrode processes. These alternative methods can offer advantages in terms of environmental impact, cost-effectiveness, and scalability.

[0236] Dry powder coating can be used as an alternative to slurry methods. In this method, anolyl active materials, conductive additives, and binders are mixed in a dry state and then applied directly to the current collector using electrostatic deposition or mechanical compression. This method eliminates the need for solvents, potentially reducing environmental impact and processing time.

[0237] Anodes can be manufactured using additive manufacturing techniques such as 3D printing. Depending on the specific material and desired electrode properties, various 3D printing methods can be used, including fused deposition modeling (FDM), selective laser sintering (SLS), or direct ink writing (DIW). This method allows for precise control over the electrode's structure and porosity.

[0238] Electrospinning is another potential method for manufacturing anodes. In this method, a solution containing anolyte materials, conductive additives, and polymer binders is extruded through a nozzle under an electric field, resulting in the formation of nanofibers. These fibers can be directly collected on a current collector to form a highly porous electrode structure with an increased surface area.

[0239] The anode can be prepared using a casting process. 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 strip can then be laminated onto the current collector.

[0240] The anode can be manufactured using a spray coating technique. A fine mist of electrode slurry is sprayed onto the current collector using compressed air or ultrasonic atomization. This method allows for the production of thin, uniform electrode layers and can be particularly useful for large-scale production.

[0241] Cryo casting is another potential method for manufacturing anodes. This method involves freezing a slurry of electrode material and then sublimating the ice to create a porous structure. The resulting porous electrode can then be sintered and attached to a current collector.

[0242] In some cases, the anode can be prepared using the sol-gel method. This method involves forming a colloidal suspension (sol) and then transforming it into a gel-like network containing the anolyte active material and other components. The gel can be applied to a current collector and subsequently heat-treated to form the final electrode structure.

[0243] For certain applications, physical vapor deposition (PVD) or chemical vapor deposition (CVD) techniques can be used to directly generate thin-film anodes on the current collector. These methods can produce highly uniform and dense electrode layers, which may be particularly beneficial for certain types of solid-state batteries.

[0244] Finally, composite anode materials can be prepared using mechanical alloying and high-energy ball milling, and then pressed into electrodes or applied to current collectors using one of the methods described above. This technique can be particularly used to produce nanostructured or amorphous anode materials with enhanced electrochemical properties.

[0245] Ball Mill Overview

[0246] Ball milling is a valuable technique for mixing and preparing materials for solid-state batteries. It is a mechanical technique widely used in various applications, including the preparation of solid-state battery components, to grind powders into fine particles and mix materials. In the case of solid-state batteries, ball milling is often used to mix and blend electrode materials, solid electrolytes, and other components. Exemplary ball milling apparatuses may include planetary ball mills, vertical ball mills, and vibratory ball mills. These apparatuses typically consist of a rotating or vibrating chamber containing grinding balls made of materials such as steel, ceramics, or zirconium oxide.

[0247] Mix evenly

[0248] Ball milling is effective in obtaining homogeneous mixtures of different powders. This is crucial for ensuring a uniform distribution of components in electrode materials and solid electrolytes, which in turn affects the overall performance of the battery.

[0249] Reduce particle size

[0250] Ball milling can reduce the particle size of the materials involved, resulting in increased surface area and improved reactivity. Smaller particle size can enhance the kinetics of electrochemical reactions, contributing to better battery performance.

[0251] Enhanced electrode-electrolyte interface

[0252] Ball milling can promote the formation of a well-defined interface between the electrode and the solid electrolyte. This is important for facilitating efficient ion transport and minimizing interfacial resistance within solid-state batteries.

[0253] Promote solid-state reaction

[0254] Ball milling can induce solid-state reactions between different components, promoting the formation of desired phases and structures within the material. This is particularly relevant for the synthesis of composite electrode materials or the preparation of the composite electrolyte materials presented herein.

[0255] Optimize conductivity

[0256] 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 good distribution of the additive materials provided herein within the solid electrolyte.

[0257] Control form

[0258] The grinding process can also affect the morphology of materials, including particle shape and size distribution. Controlling these aspects is important for achieving the electrochemical properties and overall performance required for solid-state batteries.

[0259] Energy considerations

[0260] Ball milling is an energy-intensive process that requires careful control of the milling duration and speed to avoid overheating, which can lead to undesirable reactions or damage to the material.

[0261] Anode slurry coating method

[0262] The coating of the anolyte can include techniques selected from the following: slot die coating, gravure coating, spin coating, spray coating, roll coating, curtain coating, extrusion, casting, screen printing, inkjet printing, gravure printing, thermal transfer printing, Toppan printing, intaglio printing, lithography, etc., and combinations thereof. In addition to the above techniques, other methods for coating the anolyte onto the current collector can include doctor blade coating, dip coating, and meniscus coating. Dual-groove die coating can also be used, which allows two different electrode material layers to be applied to the current collector simultaneously in a single pass. This method can potentially enable the creation of gradient structures within the electrode, thereby optimizing electrochemical and mechanical properties.

[0263] Solvents for anode slurries

[0264] Solvents used to form the anode can include water and / or organic solvents such as N-methylpyrrolidone (NMP), dimethylformamide (DMF), acetone, dimethylacetamide, dimethyl sulfoxide (DMSO), isopropanol, etc., or combinations thereof. Depending on the slurry coating thickness, productivity, etc., or combinations thereof, the solvent can be used in an amount sufficient to dissolve and disperse the electrode components (e.g., the anode active material and the binder). Other solvents that can be used include ethanol, methanol, propanol, butanol, ethyl acetate, methyl ethyl ketone, tetrahydrofuran, diethyl ether, and toluene. In some respects, the anode can 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 and cost benefits.

[0265] Dispersant for anode slurry

[0266] The dispersant forming the anode may include aqueous dispersants and / or organic dispersants, 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 (e.g., polysorbate or poloxamer). In some aspects, the anode may be prepared using methods that do not require a dispersant, such as dry powder processing or certain additive manufacturing techniques.

[0267] Anode drying technology

[0268] Anode pastes can be dried by radiant heating, electron beams (E-beams), gamma rays, or UV (G, H, I-lines) or combinations thereof to evaporate the solvent. For example, the paste can be vacuum dried at room temperature. Although the solvent is evaporated and removed by the drying step, other components do not evaporate and remain as is to form the anode. Besides the drying techniques mentioned, anode pastes can be dried using several other methods. These additional techniques offer various advantages depending on the specific materials, production requirements, and desired electrode performance.

[0269] Infrared (IR) drying can be used to rapidly heat the electrode surface, promoting efficient solvent evaporation. This method can be particularly effective for thin electrode coatings and allows for precise control of the drying process. Microwave drying is another option, which can provide volumetric heating of the electrode material, potentially achieving more uniform drying across the entire electrode thickness. In some cases, a combination of convection drying and microwave drying can be used to optimize drying speed and uniformity.

[0270] Freeze-drying, also known as lyophilization, is used in certain electrode formulations. The method involves freezing the slurry and then sublimating the solvent under vacuum conditions. Freeze-drying can help maintain the porous structure of the electrode, which can be beneficial for electrolyte permeation and ion transport.

[0271] Supercritical CO2 drying is an advanced technique that can be used for specialized electrode materials. This method involves replacing the solvent with liquid CO2, then bringing it to its supercritical state and evacuating it. This method can help preserve the precise nanostructures within the electrode and is particularly suitable for aerogel-based electrodes.

[0272] In some cases, a two-step drying method can be used. For example, an initial drying process can be carried out at a lower temperature to remove a large volume of solvent, followed by a higher temperature step to remove residual solvent and potentially initiate any desired chemical reactions within the electrode material.

[0273] For certain electrode formulations, ultrasonic drying can also be considered. This technique uses high-frequency sound waves to agitate solvent molecules, potentially accelerating the drying process and improving solvent removal from the porous structure within the electrode.

[0274] Overview of solid electrolyte layers

[0275] The solid electrolyte layer is suitable for the diffusion of lithium ions between the cathode and anode. The solid electrolyte layer provides a conductive path for the movement of charge carriers between the cathode and anode. The solid electrolyte layer is electrically connected to both the cathode and anode. In some aspects, the solid electrolyte layer is formed on and in direct contact with the cathode or anode. In other aspects, another functional layer may be disposed between the solid electrolyte layer and the cathode and / or anode.

[0276] Solid electrolyte layers can have a gradient structure, with their composition or properties varying across their thickness to optimize ion transport and interfacial compatibility. For example, the layer may have higher ionic conductivity near the electrode and higher mechanical strength in the middle.

[0277] In some applications, the solid electrolyte layer can be formed as a composite that incorporates 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.

[0278] Solid electrolyte layers may include constructed pores or channels to facilitate ion transport while maintaining mechanical integrity. These can be produced using techniques such as cryo-casting or template-based fabrication.

[0279] In some configurations, the solid electrolyte layer can be applied as multiple thin sublayers with slightly different compositions or properties, thereby allowing fine-tuning of the properties of each layer.

[0280] 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 include plasma treatment, chemical modification, or the deposition of nanoscale interfacial layers.

[0281] In some respects, solid electrolyte layers can have self-healing properties, such as including microcapsules containing electrolyte materials that can repair small cracks or defects formed during cycling.

[0282] Solid electrolyte layers can be designed to have anisotropic properties, with different ionic conductivities in different directions, to optimize ion transport between electrodes while minimizing undesirable side reactions.

[0283] In some configurations, the solid electrolyte layer may include an embedded current collector or conductive network to enhance charge transport and distribution across the battery structure.

[0284] Solid electrolyte layers can be formulated to be temperature-dependent, thereby optimizing performance over a wide range of operating conditions. This can involve phase change materials or compositions with different coefficients of thermal expansion.

[0285] In some respects, the solid electrolyte layer can be designed to be pressure-sensitive, increasing ionic conductivity under moderate compression to enhance battery performance during operation.

[0286] Materials of solid electrolyte layers

[0287] Solid electrolyte layers can transport lithium ions. There are no particular limitations on the materials used for solid electrolyte layers, as long as they allow adhesion to adjacent layers, possess suitable conductivity, and do not cause significant chemical changes within the corresponding solid-state battery within its voltage range. For example, in addition to the composite solid electrolyte materials including additive materials and sulfide-containing solid electrolyte materials provided herein, solid electrolyte layers may also include various inorganic solid electrolytes, polymer solid electrolytes, polymer gel electrolytes, but are not limited thereto. As supplementary or alternative, solid electrolyte layers may include ceramic electrolytes, glass electrolytes, organic-inorganic hybrid electrolytes, and nanostructured electrolytes, but are not limited to these types.

[0288] Inorganic solid electrolytes

[0289] Inorganic solid electrolytes can include crystalline solid electrolytes, amorphous solid electrolytes, glass-ceramic solid electrolytes, or combinations thereof, but are not limited to these. Inorganic solid electrolytes can be sulfide-based, oxide-based, or combinations thereof. Besides sulfide and oxide-based inorganic solid electrolytes, other types of inorganic solid electrolytes can include halide electrolytes, nitride electrolytes, and borate electrolytes. For example, lithium-rich anti-perovskites (LiRAPs), such as Li3Ocl and Li3Obr, lithium nitride (Li3N), and lithium borohydride (LiBH4), have been studied as potential solid electrolyte materials for lithium-ion batteries.

[0290] Sulfide solid electrolytes

[0291] As provided herein, sulfide-based solid electrolytes contain sulfur (S) and have ionic conductivity of metals 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 0.75S4, Li2S-P2S5, 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 N x ), thiolated 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 etc., or combinations thereof. In some cases, these materials are doped variants, such as Li doped with Al. 10 GeP2S 12 Alternatively, Sb-doped Li6PS5Cl can be used to further enhance ionic conductivity or stability.

[0292] Oxide solid electrolytes

[0293] Oxide-based solid electrolyte materials contain oxygen (O) and possess the ionic conductivity of metals belonging to Group I or II of the periodic table. Oxide-based solid electrolyte materials may include at least one selected from the group consisting of: LLTO compounds, Li6La2CaTa2O 12 Li6La2Anb2O 12 (A is Ca or Sr), Li₂Nd₃TeSbO 12 Li3BO 2.5 N 0.5Li9SiAlO8, LAGP compounds, LATP 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-type compounds, LIPON-type compounds, perovskite-type compounds, NASICON-type compounds, and LLZO-type compounds or derivatives (e.g., Al-doped Li7La3Zr2O). 12 and Ta-doped Li7La3Zr2O 12 As potential oxide-based solid electrolytes, lithium-rich anti-perovskites, such as Li3Ocl and Li3Obr, have also been investigated. In some cases, composite oxide electrolytes combining multiple oxide materials, such as the LLZO-LATP complex, can be used to take advantage of the advantages of different oxide systems.

[0294] Polymer solid electrolyte

[0295] Polymer solid electrolytes are complexes of electrolyte salts and polymer resins, and possess lithium-ion conductivity. Polymer solid electrolytes may include polyether polymers, polycarbonate polymers, acrylate polymers, polysiloxane polymers, phosphazene polymers, polyethylene derivatives, epoxy alkane derivatives, phosphate ester polymers, polyalginic lysine, polyester sulfides, polyvinyl alcohol, polyvinylidene fluoride, polymers containing ion-dissociating groups, poly(ethyleneimine) (PEI), poly(methyl methacrylate) (PMMA), poly(acrylonitrile) (PAN), poly(vinyl succinate) (PES), biopolymers (e.g., chitosan and cellulose derivatives), or combinations thereof. Solid polymer electrolytes may include polymer resins, such as branched copolymers of a polyethylene oxide (PEO) backbone copolymerized with comonomers comprising amorphous polymers (e.g., PMMA, polycarbonate, polydisiloxane (PDMS), and / or phosphazene), comb-like polymers, crosslinked polymer resins, polyethylene glycol (PEG), polypropylene oxide (PPO), polyacrylonitrile (PAN), poly(methyl methacrylate) (PMMA), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), poly(ethylene oxide-co-propylene oxide) (PEO-PPO), poly(ethyleneimine) (PEI), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), various block copolymers or graft copolymers incorporated in these materials, or combinations thereof.

[0296] Polymer gel electrolyte

[0297] 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 gel electrolytes based on polyethylene oxide (PEO), poly(methyl methacrylate-co-ethyl acrylate) (PMMA-EA), poly(acrylonitrile-co-methyl methacrylate) (PAN-MMA), poly(vinyl acetate) (PVAc), poly(ethylene glycol diacrylate) (PEGDA), poly(vinylpyrrolidone) (PVP), poly(ethylene glycol methyl ether acrylate) (PEGMEA), poly(ethylene glycol methyl ether methacrylate) (PEGMEMA), poly(ionic liquid) (PIL), poly(ethylene glycol-co-propylene glycol) (PEG-PPG), poly(vinyl alcohol-co-ethylene) (PVA-PE), poly(acrylamide) (PAM), poly(2-hydroxyethyl methacrylate) (PHEMA), poly(ethylene glycol-co-polyethylene oxide) (PEG-PEO), and poly(methacrylic acid) (PMAA) to optimize the electrochemical and physical properties of solid electrolytes.

[0298] Electrolyte salts

[0299] Electrolyte salts are ionizable lithium salts and can be converted from Li... + X - Indicates. X - It may include at least one anion selected from the group consisting of: F - Cl - ,Br - NO3 - N(CN)2 - BF4 - ClO4 - AlO2 - 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 - For example, the lithium salt can be at least one selected from the group consisting of: 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 imine, lithium bis(oxalate)borate (LiBOB), lithium difluoro(oxalate)borate (LiDFOB), lithium bis(fluorosulfonyl)imine (LiFSI), lithium 4,5-dicyano-2-(trifluoromethyl)imidazolium (LiTDI), lithium bis(trifluoromethanesulfonyl)imine (LiTFSI), and lithium bis(fluorosulfonyl)imine (LiFSI), and combinations thereof. Electrolyte salts may include any combination of the salts described herein.

[0300] Amount of electrolyte salts

[0301] Based on the total weight of the solid electrolyte layer, the solid electrolyte layer 106 may contain about 0, 50, 60, 70, 80, 100, 200, 300, or 400 parts of electrolyte salt (if present). In some aspects, the range of electrolyte salts in the solid electrolyte layer can be determined by selecting any two numbers listed in the preceding sentence, for example, from about 0 parts to about 400 parts, or from about 60 parts to 400 parts, based on the total weight of the solid electrolyte layer.

[0302] ionic conductivity of solid electrolyte layer

[0303] The solid electrolyte layer may include suitable reduction stability and / or ionic conductivity. Since the solid electrolyte layer primarily functions to transport lithium ions between electrodes, it may include approximately 10... -7 S / cm, 10 -6 S / cm, 10 - 5 S / cm or 10 -4 Required ionic conductivity of S / cm or higher.

[0304] Thickness of solid electrolyte layer

[0305] The thickness t6 of the solid electrolyte layer can be about 3, 5, 10, 15, 20, 25, 30, 50, 70, 100, 150, 200, 300, 400, 500, or 1000 μm. In some aspects, the range of the thickness t6 of the solid electrolyte layer can be formed by selecting any two values ​​listed in the preceding sentence, for example, about 5 μm to about 1000 μm, about 30 μm to about 100 μm, or about 30 μm to about 50 μm.

[0306] Unfinished products

[0307] Battery cells can be supplied as unfinished products. In some cases, the cells are stored, transported, and / or delivered to distributors, customers, etc., who have completed the manufacture of battery modules or products including the cells. In other cases, the cells are finished battery modules or products.

[0308] Sealed battery

[0309] Solid-state batteries are manufactured by sealing their casings, enabling them to function as batteries. The sealing process involves various techniques to ensure the protection of internal components from external environmental factors and to maintain the integrity of the battery structure. For example, methods such as laser welding, ultrasonic welding, or adhesive bonding can be used to hermetically seal the casing. 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 ingress, which can potentially degrade the performance of sulfide-based solid electrolytes. Additionally, 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 undergoes final quality control checks, which may include electrical testing, leak detection, and visual inspection. After passing these checks, the solid-state battery can be packaged and sold as a finished product for integration into various electronic devices, electric vehicles, energy storage systems, and more.

[0310] Battery configuration

[0311] Solid-state batteries are available in a variety of configurations to suit different applications and device requirements. In some cases, batteries can be manufactured in a cylindrical form, which can be advantageous for certain types of portable electronic devices or automotive applications. Alternatively, solid-state batteries can be made in a prismatic form, which allows for more efficient space utilization in devices with a rectangular form factor. In other cases, a pouch form can be used, offering flexibility in shape and potentially reducing the overall weight of the battery. The pouch form is also particularly suitable for solid-state batteries due to the ease with which uniform pressure can be applied and controlled within the battery. The choice of configuration can depend on factors such as intended use, space constraints, thermal management requirements, and manufacturing considerations. In some cases, hybrid or custom configurations combining different forms of components can be used to meet specific design needs. The diversity of battery form factors enables the integration of solid-state batteries into a wide range of products, from small wearable devices to large energy storage systems.

[0312] Voltage

[0313] Solid-state batteries are configured to output voltages of approximately 1, 2, 3, 4, 5, 6, 10, 12, 20, 24, 30, 40, 48, 50, 60, 70, 80, 90, 96, 100, 200, 300, 400, or 500 VDC. In some aspects, the range of output voltage for solid-state batteries can be formed by selecting any two numbers listed in the preceding sentence, for example, from approximately 1 VDC to approximately 500 VDC.

[0314] capacity

[0315] Solid-state batteries are configured to have a specific capacity of approximately 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, or 300 mAh / g or higher. In some aspects, the range of output voltage of the solid-state battery 100 can be formed by selecting any two numbers listed in the preceding sentence, for example, approximately 100 mAh / g to approximately 300 mAh / g.

[0316] Calculation of volume expansion

[0317] Solid-state batteries can include the desired 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 ratio of the change in thickness after the first charge-discharge cycle to the initial thickness of a given element. The first charge-discharge cycle is performed as follows: the battery is CC-CV charged at 0.1C and discharged from 0.02C to 4.25 to 4.4V, and then CC-discharged at 0.1C to 3V. The volumetric expansion rate is calculated using Equation 1 below, where A can represent the thickness before charge-discharge, and B can 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] × 100C - ratio The C-rate used here refers to the rate at which the 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 discharge current at 1C will be 20 amperes.

[0318] Other exemplary methods for measuring and calculating the volume expansion rate of solid-state batteries may include using volume expansion measurements (e.g., gas density measurements), in-situ expansion measurements, X-ray tomography, strain gauge measurements, optical methods (e.g., digital image correlation or laser interferometry), pressure-based methods, and electrochemical strain microscopy.

[0319] Characteristics of secondary batteries

[0320] The battery may include a cathode; an anode; and any one of the electrolytes described above. Furthermore, the disclosed battery exhibits at least about 70% capacity retention after at least about 300 cycles at a charge / discharge rate of about C / 5 to about 1C.

[0321] Furthermore, the battery sustains at charge / discharge rates from approximately C / 5 to approximately 1C (including exemplary values ​​such as approximately C / 4, approximately C / 3, approximately C / 2, approximately 3C / 5, approximately 2C / 3, approximately 3C / 4, approximately 4C / 5 (or approximately C / 5 to 4C / 5, or C / 2 to approximately 4C / 5, or approximately C / 4 to approximately 2C / 3, etc.) for at least approximately 250 cycles, at least approximately 300 cycles, at least approximately 350 cycles, at least approximately 400 cycles, at least approximately 450 cycles, and at least... The battery exhibits a capacity retention of at least approximately 60%, at least approximately 65%, at least approximately 700%, at least approximately 750%, at least approximately 800%, at least approximately 850%, at least approximately 900%, at least approximately 950%, or at least approximately 1000 cycles, respectively. It should be understood that, in some respects, when evaluated under the conditions disclosed above, the battery can consistently exhibit the capacity retention disclosed above for more than approximately 1000 cycles, more than approximately 1500 cycles, or even more than approximately 5000 cycles.

[0322] In a further aspect, the battery exhibits a capacity retention rate of approximately 60% to less than or equal to 100%, including approximately 60% to approximately 95%, approximately 70% to approximately 90%, approximately 65% ​​to approximately 99%, etc., at exemplary charge / discharge rates of approximately C / 5 to approximately 1C, including approximately C / 4, approximately C / 3, approximately C / 2, approximately 3C / 5, approximately 2C / 3, approximately 3C / 4, approximately 4C / 5 (or approximately C / 5 to 4C / 5, or C / 2 to approximately 4C / 5, or approximately C / 4 to approximately 2C / 3, etc.), for a duration of at least approximately 250 cycles to approximately 1000 cycles, including approximately 250 cycles to approximately 800 cycles, or approximately 300 cycles to approximately 1000 cycles, or approximately 400 cycles to approximately 1000 cycles (and any values ​​within these ranges).

[0323] In a further aspect, the battery may include a separator. In these aspects, any separator known in the art capable of achieving the desired results may be used. For example, but not limited to, the separator may include glass fibers, porous polymer membranes with or without a ceramic coating (e.g., polyethylene or polypropylene-based materials), or composites (e.g., porous membranes of inorganic particles and binders). An exemplary polymer separator is a polyethylene (PE) membrane. Another exemplary polymer separator is a polypropylene (PP) membrane. The separator may be infused with any electrolyte disclosed herein.

[0324] In a further aspect, the battery includes an anode, wherein the anode comprises carbon, silicon, Li, Li alloys, Li intermetallic compounds, Li compounds, TiNb2O7, Li4Ti5O 12 Or any combination thereof. In a further aspect, the anode comprises a metal current collector that serves as a substrate for the anode active material formed in situ during the first cycle of the battery. In a further aspect, the anode is formed in situ on a bare current collector, wherein the current collector may comprise any material disclosed herein. In some aspects, such a battery may be referred to as an anode-free configuration.

[0325] It should be understood that similar electrolytes can be used in batteries based on potassium or sodium anodes, where the salt is exchanged for a salt containing potassium or sodium cations.

[0326] In a further aspect, the cathode present in the battery can be a metallic cathode or a composite cathode. In an even further aspect, the cathode includes layered oxide cathodes, vanadium-based cathodes, sulfur-based cathodes, manganese-based cathodes, rock salt cathodes, disordered rock salt cathodes, lithium-rich cathodes, NMC (nickel-manganese-cobalt oxide) cathodes, NCA (nickel-cobalt-aluminum oxide) cathodes, NFM (nickel-iron-manganese oxide) cathodes, LCO (lithium-cobalt oxide) cathodes, LFP (lithium iron phosphate) cathodes, fluoride cathodes, sulfur-selenium cathodes, sulfur cathodes, selenium cathodes, tellurium cathodes, spinel cathodes, olivine cathodes, or any combination thereof.

[0327] In yet another exemplary and non-limiting aspect, the cathode active material may comprise a high-density nickel-rich layered transition metal oxide (Li[Ni]). x Mn y Co z [O2(x+y+z=1)), lithium iron phosphate (LFP), lithium manganese oxide (LiMn2O4) or nickel-doped lithium manganese oxide (Li[Ni]O2(x+y+z=1)), 0.5 Mn 1.5 ]O4).

[0328] In a further aspect, the cathode composite material may contain additional components. For example, but not limited to, in some aspects, the cathode composite material may contain one or more fillers. In such an exemplary aspect, the one or more fillers may include conductive fillers, flame retardants, fire retardants, stabilizers, antibacterial agents, or any combination thereof. For example, but not limited to, the one or more fillers may include carbon black, modified carbon black, graphene, multilayer graphene, carbon fibers, carbon nanotubes, carbon nanospheres, graphite, reduced graphene oxide, or any combination thereof. In yet another aspect, the cathode may contain a binder, such as polyvinylidene fluoride (PVDF), poly(ethylene oxide), cellulose, carboxymethyl cellulose (CMC), polytetrafluoroethylene (PTFE), styrene-butadiene rubber (SBR), polyacrylic acid (PAA), polyvinyl alcohol (PVA), polyvinyl butyral (PVB), polyvinylpyrrolidone (PVP), ethyl cellulose (EC), copolymers thereof, or any combination thereof.

[0329] However, in a further aspect, fillers are those that do not negatively affect the ionic conductivity or stability of the cathode composite material.

[0330] In a further aspect, the battery exhibits a coulombic efficiency greater than about 80%, greater than about 85%, greater than about 90%, greater than about 95%, or greater than about 99% within at least about 100 cycles, at least about 200 cycles, at least about 300 cycles, at least about 400 cycles, at least about 500 cycles, at least about 600 cycles, at least about 700 cycles, at least about 800 cycles, at least about 900 cycles, or at least about 1000 cycles.

[0331] In a further aspect, the battery exhibits a coulombic efficiency of not less than about 99.9%, not less than about 99.9%, not less than about 95%, not less than about 92%, not less than about 90%, not less than about 85%, or not less than about 80% within at least about 100 cycles, at least about 200 cycles, at least about 300 cycles, at least about 400 cycles, at least about 500 cycles, at least about 600 cycles, at least about 700 cycles, at least about 800 cycles, at least about 900 cycles, or at least about 1000 cycles. In a further aspect, the coulombic efficiency can range from about 80% to about 100% within at least about 100 cycles, at least about 200 cycles, at least about 300 cycles, at least about 400 cycles, at least about 500 cycles, at least about 600 cycles, at least about 700 cycles, at least about 800 cycles, at least about 900 cycles, or at least about 1000 cycles, including exemplary values ​​of about 85%, about 90%, about 95%, about 99%, and about 99.99%. In a further aspect, the coulombic efficiency can have any value falling between any two of the foregoing values, or it can fall within any range formed by any of the foregoing values. For example, the coulombic efficiency can be about 80% to about 100%, or about 80% to about 99%, or about 80% to about 95%, and so on. In a further aspect, such coulomb efficiency can be achieved for at least about 100 cycles, or more than about 100 cycles, more than about 200 cycles, more than about 500 cycles, more than about 1000 cycles, more than about 2000 cycles, more than about 5000 cycles, more than 10000 cycles, or even more than 100000 cycles.

[0332] In a further aspect, the battery disclosed herein is configured to operate within a temperature range of about -30°C to about 60°C, including exemplary values ​​of about -25°C, about -20°C, about -15°C, about -10°C, about -5°C, about 0°C, about 25°C, about 30°C, about 35°C, about 40°C, about 45°C, about 50°C, and about 55°C. In a further aspect, the battery can operate at a temperature falling between any two of the foregoing values, or it can fall within any range formed by any of the foregoing values. For example, but not limited to, the battery can operate at temperatures ranging from approximately -25°C to approximately 60°C, approximately -15°C to approximately 60°C, approximately -10°C to approximately 60°C, approximately -5°C to approximately 60°C, approximately -15°C to approximately 50°C, approximately -15°C to approximately 40°C, approximately 0°C to approximately 60°C, approximately 5°C to approximately 60°C, approximately 20°C to approximately 60°C, approximately 20°C to approximately 50°C, and approximately 20°C to approximately 40°C.

[0333] In a further aspect, the battery exhibits a capacity retention rate that is at least about 10%, at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, or at least about 80% higher than that of a reference battery, which comprises substantially the same cathode material, anode material, and separator containing nickel-manganese-cobalt oxide, and whose electrolyte contains about 1 M LiPF6 in EC:DMC:DEC (about 1:1:1 volume ratio).

[0334] Furthermore, when discharged at rates from approximately 0.1C to approximately 10C, the battery exhibits a specific discharge capacity of approximately 50 mAh / g to approximately 300 mAh / g. In other aspects, the battery exhibits specific discharge capacities of approximately 50 mAh / g or higher, approximately 75 mAh / g or higher, approximately 100 mAh / g or higher, approximately 120 mAh / g or higher, approximately 150 mAh / g or higher, approximately 175 mAh / g or higher, approximately 200 mAh / g or higher, approximately 225 mAh / g or higher, approximately 250 mAh / g or higher, and approximately 275 mAh / g or higher. In other aspects, the battery exhibits specific discharge capacities of approximately 300 mAh / g or lower, approximately 275 mAh / g or lower, approximately 250 mAh / g or lower, approximately 225 mAh / g or lower, approximately 200 mAh / g or lower, approximately 175 mAh / g or lower, approximately 150 mAh / g or lower, approximately 125 mAh / g or lower, approximately 100 mAh / g or lower, or approximately 75 mAh / g or lower. In a further aspect, the battery exhibits a specific discharge capacity of approximately 50 mAh / g to approximately 300 mAh / g, including exemplary values ​​of approximately 50 mAh / g, approximately 75 mAh / g, approximately 100 mAh / g, approximately 125 mAh / g, approximately 150 mAh / g, approximately 175 mAh / g, approximately 200 mAh / g, approximately 225 mAh / g, approximately 250 mAh / g, and approximately 275 mAh / g. In a further aspect, the specific discharge capacity exhibited by the battery can have any value falling between any two of the foregoing values, or it can fall within any range formed by any of the foregoing values. For example, the battery exhibits specific discharge capacities of approximately 50 mAh / g to approximately 300 mAh / g, approximately 50 mAh / g to approximately 200 mAh / g, approximately 50 mAh / g to approximately 100 mAh / g, approximately 75 mAh / g to approximately 300 mAh / g, approximately 100 mAh / g to approximately 300 mAh / g, etc. In a further aspect, when discharged at a rate from about 0.05C to about 20C, the battery exhibits the specific discharge capacity disclosed above. In these aspects, the discharge rate can be about 0.1C, about 0.2C, about 0.3C, about 0.4C, about 0.5C, about 1C, about 2C, about 4C, about 5C, about 6C, about 7C, about 8C, about 9C, about 10C, about 11C, about 12C, about 13C, about 14C, about 15C, about 16C, about 17C, about 18C, and about 19C. In an even further aspect, the discharge rate can have any value falling between any two of the aforementioned values, or it can fall within any range formed by any of the aforementioned values. For example, the discharge rate can be from about 0.05C to about 20C, from about 0.1C to about 20C, from about 0.1C to about 10C, from about 0.5C to about 20C, from about 0.2C to about 10C, from about 0.5C to about 8C, from about 2C to about 10C, from about 4C to about 10C, etc.

[0335] This document also discloses systems comprising one or more of any of the batteries disclosed herein. For example, the system may comprise at least about 2, at least about 5, at least about 10, at least about 50, at least about 100, at least about 500, or at least about 1000 batteries.

[0336] This document also discloses articles that may include the batteries or systems disclosed herein. For example, articles may include vehicles (land, sea, air, or space-adapted vehicles), handheld devices, wearable electronic devices, fixed electronic devices, power tools, toys, energy storage devices, etc.

[0337] Example

[0338] The following embodiments are not intended to be limiting. The above disclosure provides many different aspects for implementing the features of the invention, and the following embodiments describe certain aspects. It should be understood that other modifications and methods known to those skilled in the art can also be applied to the following experimental procedures without departing from the scope of the invention.

[0339] Experiment 1

[0340] The electrolyte compositions or additive-containing electrolytes (ACE) of the present disclosure are compared below with conventional ether electrolytes (CEE).

[0341] Preparation of electrolytes and electrodes

[0342] For the ether electrolyte, 1M lithium bis(fluorosulfonyl)imide (LiFSI, Solvitonic) was dissolved in anhydrous tetrahydrofuran (THF, Sigma-Aldrich). Tetrabutylammonium tetrafluoroborate (TBATFB, Sigma-Aldrich) was treated to remove any excess water using the following method: After vacuum drying at 80°C for 48 hours, TBATFB was dissolved in THF and then refluxed under argon for 2 hours. The salt was then recrystallized in anhydrous ethyl acetate (Sigma-Aldrich) to obtain white crystals. Then, 0.1M (Example 1), 0.5M (Example 2), and 1.0M (Example 3) concentrations of TBATFB were added to 1M Li / THF electrolyte. A control solution of 1M LiFSI / THF electrolyte without the addition of TBATFB was also prepared (Comparative Example 1). LiFePO4 (LFP, MSESupplies) and single-crystal LiNi were prepared by slurry casting. 0.88 Co 0.09 Al 0.03O2 (NCA-88, MSESupplies) cathode. Initially, active material, SuperP carbon black, and polyvinylidene fluoride (PVDF) binder (MSESupplies) were mixed in anhydrous N-methylpyrrolidone (NMP, Sigma-Aldrich) at a mass ratio of 90:5:5 to produce a slurry. The slurry was then cast onto aluminum foil using a doctor blade method and punched into 13mm discs. Subsequently, the cathode was pressed at 90°C using a roller press. Before assembling the battery cell, the electrodes were vacuum dried at 65°C for at least 24 hours.

[0343] Electrochemical characterization

[0344] All tests were performed using a 2032-type coin cell assembled in an argon-filled glove box (MBRAUN, O2 and H2O < 0.1 ppm), with polypropylene (Celgard 2325) as the separator. Li||Li symmetric cells and Li||Cu asymmetric cells were assembled using 250 μm Li sheets as reference and counter electrodes. The exchange current density was determined using Tafel plots and the Butler-Volmer equation. To generate the Tafel plots, a current density of 0.5 mV / s was used. -1 The constant rate is from -0.2 to 0.2 V (relative to Li / Li). + The Li||Li cell was scanned within its voltage range. The overpotential required by the Butler-Volmer equation was obtained by constant current charging / discharging of the Li||Li cell (using a current of 20-100 μA). The passivation stability of the Li metal anode was determined by testing at 0 V (relative to Li / Li). + The Li||Cu cell was set up and leakage current was monitored for 10 hours to evaluate its performance. Li calendar aging was assessed by first depositing and then removing a 5mAh / cm² cell. -2 Li, and then coated with 5mAh cm -2 The Li was then used. The cell was then allowed to rest for 0, 1, and 5 days, and then stripped to 1V (relative to Li / Li). + The Li||LFP all-cell battery was tested using a 35μm thick Li anode and a 4 mAh cm⁻¹. -2 The loaded LFP cathode is at 2.5-4.0V (relative to Li / Li). + The testing was conducted within the voltage range of ) . The Li||NCA-88 all-cell battery was tested using a 2mAh cm -2 or 4 mAhcm -2 NCA-88 cathode coupling with 35μm or 50μm thick Li anode at 2.7-4.3V (relative to Li / Li). + The test was conducted within the voltage range of [missing information]. Within the same voltage range, copper foil was used as the anode and 2 mAh / cm² [missing information]. -2NCA-88 cathode, assembled anode-free Cu||NCA-88 cell. Electrochemical float test by placing the Li||NCA-88 cell at 4.3V (relative to Li / Li). + The leakage current was measured. Intermittent galvanostatic titration (GITT) was performed by charging and discharging at 0.02C with 45-minute rest intervals. Electrochemical impedance spectroscopy (EIS) experiments were conducted using a peak voltage of 10 mV at an open-circuit voltage. -2 Hz to 10 5 Electrochemical analyses were performed at Hz. Ionic conductivity and transfer number of the electrolyte were measured using EIS with SS||SS and Li||Li symmetrical cells, respectively. Transfer number was determined using the Bruce-Vincent method with a polarization voltage of 10 mV and a time period of 2 hours. Total impedance of Li||Li and Li||NCA-88 cells was measured under the same conditions. A BioLogic VMP3 and Arbin battery cycler were used for all electrochemical analyses.

[0345] Material characterization

[0346] The morphology of Li metal deposits was examined using scanning electron microscopy (SEM, SU-8230). The solvation structure of the electrolyte was analyzed using Raman spectroscopy (Renishaw Qontor Dispersive Raman Spectrometer). The chemical composition of the SEI and CEI was investigated using X-ray photoelectron spectroscopy (Thermo Scientific K-alpha XPS instrument) under hermetically sealed transfer conditions. High-resolution XPS was used to fit the Li 1s, C 1s, O 1s, F 1s, and S2p spectra using XPSPEAKS 4.1. One-dimensional spectra were recorded using a Bruker AVANCE III HD14.1T (ω1H = 600 MHz) spectrometer from BBProdigyCryoProbe. 7 Li, 19 F{ 1 H} and 17 ONMR spectra. Internal controls were provided for all spectra by adding glass capillaries containing appropriate reference solutions. 7 The Li NMR spectrum is referenced to LiCl (1 M in D2O) at 0.0 ppm. 19 FNMR spectrum reference -74.5ppm (δ 19 LiPF6 at F) (1M in 1:1 v / vEC / DMC); 1:1 v / v), 17 The O spectrum refers to D2O at 0.0 ppm.

[0347] Calculation details

[0348] Density functional theory (DFT) calculations were performed using the Viennaab-initio simulation package (VASP). The core electron representation was performed using the Projected Enhanced Wave (PAW) method. Within the framework of the Generalized Gradient Approximation (GGA), the determination of the exchange correlation function relied on the Perdew-Burke-Ernzerhof (PBE) method. A plane wave cutoff energy of 400 eV was chosen, and 10... - 5 The energy convergence threshold of eV is used to continue calculations until the atomic force decreases to 0.02 eV Å. -1 The following describes the process. To optimize the molecular adsorption structure, the Brillouin region in reciprocal space was integrated using a 1×1×1k-point grid, and ab-initio molecular dynamics (AIMD) calculations were performed using a 1×1×1k-point grid to improve computational speed. Spin polarization was considered in all calculations except for the AIMD simulations. The Li(100) surface was modeled using a 6×6 superlattice containing 3 layers, with the bottom two layers fixed to represent the substrate region. For surface AIMD calculations, 50,000 steps were performed at a time step of 1 fs at a temperature of 300 K. To prevent interactions caused by periodic boundary conditions in relaxation processes involving molecules and the surface, a vacuum of at least 15 Å was included. For calculating the solvation structure in the electrolyte, a general graph deep learning interatomic potential (M3GNet) was used for fast calculations. Conventional ether electrolytes were simulated using 5 LiFSI and 60 THF molecules, while the electrolytes of the aspects of this disclosure (Examples 1 to 3) included an additional TBATFB in addition to the CEE. Molecular dynamics simulations were performed at 350 K for 30 ps to observe the electrolyte solvation structure.

[0349] Evaluation and optimization of electrolytes

[0350] The optimization process was initiated by adjusting the concentration of the fluorinated additive to enhance the compatibility between the electrolyte and the LMA. Li reversibility was evaluated through a Li plating / removal process on a copper (Cu) substrate, where the plating was performed at 1 mAcm⁻¹. -2 Current density and 1mAhcm -2 Perform 300 cycles within the area capacity ( Figure 8 The addition of TBATFB resulted in a coulombic efficiency (CE) exceeding 99%, compared to the 97.8% coulombic efficiency observed in the ether electrolyte, demonstrating enhanced LMA stability. This trend remained consistent when the electrolyte was tested using the improved Aurbach protocol. Figure 9 It is noteworthy that, up to the 50th cycle, the electrolyte concentration (CE) of 1M LiFSI + 1M BATFB in THF gradually increased, attributed to the high salt concentration, a trend consistent with the high-concentration electrolyte (HCE) of 3M LiFSI. Figure 9 ). At 1 mAcm -2 At this point, the electrolyte with 0.1 MTBAFTB showed a minimum initial Li nucleation overpotential of 25 mV. Figure 10 A lower nucleation overpotential is advantageous because it thermodynamically favors the formation of larger Li nuclei, resulting in a compact Li deposition morphology. The ionic conductivity and Li selectivity of these electrolyte systems were further analyzed.

[0351] The addition of TBATFB typically leads to a decrease in ionic conductivity, except for 0.1 MTBATFB, which shows a negligible change compared to ether electrolytes. Figure 11 The electrolyte viscosity increases with increasing TBATFB concentration, indicating a decrease in ion mobility within the electrolyte. Figure 12 With the addition of TBATFB, Li was observed to... + The increase in the number of transitions ( Figure 13 and Figure 14 This is attributed to TBA. + Cations and FSI - and BF4 - The attractive coulombic interaction between anions enhances cation selectivity. Then, by [further action] at 0V (relative to Li / Li [missing value]), [further action is taken]. + The passivation stability of Li was evaluated by measuring the leakage current in a Li||Cu asymmetric cell. Figure 15 The low leakage current (below 1 μA) indicates that the TBATFB additive increases the stability of the SEI. The electrolyte exchange current density was measured using two methods: extrapolating the Tafel plot and applying the Butler-Volmer equation at low overpotentials. Figure 16 , Figure 17 and Figure 18 Both methods exhibited a consistent trend. In both approaches, the 0.1MTBATFB additive and the 0.5MTBATFB additive showed improved electrochemical activity compared to ether electrolytes.

[0352] To optimize the additive-modified electrolyte, key parameters at different additive concentrations were compared, including exchange current density, passivation stability, CE, ionic conductivity, transfer number, and nucleation overpotential. Figure 19 As shown, compared with Comparative Example 1 (without TBATFB), Example 2 (1M LiFSI / THF + 0.5MTBATFB), and Example 3 (1M LiFSI / THF + 1MTBATFB), Example 1 (1M LiFSI / THF + 0.1MTBATFB) exhibits superior exchange current density, passivation current, coulombic efficiency, ionic conductivity, and Li +The results indicate that the optimal molar ratio of LiFSi / THF to TBATFB in the electrolyte is approximately 1:0.1.

[0353] Electrolyte solvation structure

[0354] The solvated structure of ACE (Example 1) was compared with that of CEE (Comparative Example 1). First, density functional theory (DFT) calculations were applied to verify the binding of TBATFB to the THF solvent molecules. Figure 5 a and Figure 6 Next, molecular dynamics (MD) simulations provided further insight into the molecular interactions within the solvation shell. Figure 5 a and Figure 5 c). Both CEE and ACE exhibit unique SSIP structures, characterized by Li + Coordination is mainly governed by solvent molecules. Figure 5 d). In these electrolyte systems, Li + The coordination kinetics with THF solvent were obtained by Raman spectroscopy. Figure 5 e). For CEE and ACE, the peak of free THF (948 cm⁻¹) -1 ) and free FSI - Peak (719cm) -1 The peak associated with CIP / AGG (742 cm⁻¹) remained in the same position. -1 ) and Li + Coordination THF peak (955 cm⁻¹) -1 It does not exist in either CEE or ACE. Figure 20 These results indicate that the presence of TBATFB does not alter the solvation structure of the electrolyte. Nuclear magnetic resonance experiments were performed to verify the equivalent local environment in CEE and ACE. 7 LiNMR spectrum shows 7 The change in the Li signal is negligible (δ of CEE). 7 Li) = -0.408ppm, compared to ACE's δ( 7 The concentration of Li (Li) was -0.469 ppm, indicating that Li in CEE and ACE was present. + Similar binding energies Figure 5 f). 19 FNMR spectra reveal that FSI - The local environment is highly similar in both electrolytes (δ in CEE and ACE). 19 F) were both 51.17 ppm, while the characteristic BF4 - The peak exists only in ACE (δ( 19 F) = -156.35ppm); Figure 5g). This further leads to 17 Support from ONMR spectroscopy ( Figure 5 h). LiFSI 17 The ONMR signal is the same in both electrolytes (δ( 17 O)=169.0ppm). THF 17 Tiny changes in the ONMR signal (δ in CEE) 17 O) = 15.5 ppm, compared to δ( O) in ACE 17 The concentration of O (=15.4ppm) indicates that the local coordination environment of the solvent molecules is similar in both electrolytes.

[0355] Enhanced Li metal stability

[0356] At increased current density and capacity (3 mAcm, respectively) -2 and 3 mAhcm -2 The CE of Li||Cu asymmetric cells is evaluated to investigate the reversibility of Li. Figure 21 The mean CE values ​​for CEE and ACE were 97.0% and 99.2%, respectively. LMA corrosion during the calendar aging process was evaluated after 0, 1, and 5 days of aging. Figure 21 b and Figure 22 With prolonged aging time, CEE showed a relatively linear decrease, while ACE exhibited a stable capacity loss, indicating its self-passivation behavior. To evaluate LMA stability, at 10 mAcm... -2 and 4 mAhcm -2 ( Figure 21 c) and 20 mAcm -2 and 20 mAhcm -2 ( Figure 21 d) Li||Li symmetric cells were tested at high current density and areal capacity. Under both conditions, cells cycled with CEE experienced short circuits during the early cycling phase, while ACE exhibited stable and extended cycling performance. ACE also demonstrated excellent performance at 1 mAcm⁻¹. -2 and 1 mAhcm -2 Stable cyclic stability during 1000 cycles under a milder approach Figure 23 To decipher the underlying failure mechanism, Li||Li symmetric cells were tested at 1 mAcm⁻¹. -2 and 1 mAhcm -2 The next 100 cycles were performed and analyzed. Scanning electron microscopy (SEM) images showed moss-like and dendritic Li deposits as porous sediments in CEE, compared to a dendrite-free, densely packed morphology in ACE. Figure 21 e and Figure 21f). Electrochemical impedance spectroscopy showed that the impedance in the CEE increased significantly from 77 Ω to 141 Ω (f). Figure 24 Conversely, ACE showed a slight increase from 75 Ω to 95 Ω, indicating the formation of a thin and robust SEI. This was achieved by measuring the ACE when solvated Li... + The potential energy of ions deposited on the LMA surface was used to study the dendrite suppression mechanism of ACE. Figure 2 DFT calculations show that in each Li + Within the corresponding 1 to 6 THF molecules, Li[THF]4 + (-1.81 eV) is the most likely solvation structure. Figure 21 g). The 0.148 eV potential barrier of CEE can be attributed to the desolvation of THF molecules during Li deposition. Figure 21 h). The sharp drop in potential energy at the final reaction coordinates indicates thermodynamically favorable Li deposition. On the other hand, micro-motion elastic band (NEB) calculations reveal that for ACE, the potential energy for Li... + The energy barrier increases by approximately 0.199 eV, indicating that TBA... + The shielding effect of the cation layer. Typically, due to the increased electric field concentration at the pre-existing dendrites, Li... + Three-dimensional (3D) diffusion of ions promotes dendrite growth, a phenomenon often referred to as the "tip effect." Due to TBA... + Cations tend to aggregate near 3D protrusions, thus the increased energy barrier in ACE restricts Li on dendrites. + The flux effectively reduced dendrite growth and promoted uniform, dense Li deposition.

[0357] Characterization of SEI on a circulating Li metal anode

[0358] Using X-ray photoelectron spectroscopy (XPS) and Ar + Sputter depth profiling was used to analyze the chemical composition of the SEI. Figure 25 a). XPS elemental analysis revealed a consistent decrease in carbon content in both electrolyte systems during etching, indicating the formation of an SEI with an organic-rich outer layer and an inorganic-rich inner layer. Specifically, Li₂CO₃ (290.5 eV) was identified as the dominant carbon material on the LMA cyclic in the CEE. Figure 25 b) Consistent with other low-concentration ether electrolytes. The significant presence of Li₂CO₃ is often associated with SEI instability due to its tendency to decompose into gaseous byproducts. In the case of SEIs with ACE, BF₄⁻ is involved in SEI formation. - The involvement of anions is evident, as highlighted by the prominent BF peak (688.1 eV) and Li-F peak (684.8 eV) in the F1s spectrum. Figure 25 c). The alkyl lithium oxide peak (RO-Li, 533.0 eV, O1s) and CO peak (286.0 eV, C1s) indicate the decomposition of the free THF solvent ( Figure 25 d). Conversely, the SEI with ACE exhibits a significant Li₂O peak (529.3 eV), which is known to enhance the Li₂O content within the SEI. + Diffusion. The peak intensity in the Li1s spectrum is in good agreement with the peaks shown in the C1s, O1s, and F1s spectra. Figure 25 e). In the S2p spectrum, compared to CEE, ACE showed lower levels of SO2F (169.6 and 171.2 eV), but exhibited a novel SOx (166.2 eV) peak, indicating a more extensive decomposition of FSI (e). Figure 25 f). The fluorination behavior was verified using MD simulations, where we observed BF4 - Rapid decomposition at the LMA surface is attributed to its sensitivity to reduction. Figure 3 It should be noted that in FSI - During anion decomposition, significant distortion was detected in the (100) plane of the Li lattice. Figure 4 Conversely, BF4 - The anion fluorinated LMA, and also due to its affinity for FSI - The Li lattice structure is maintained by stronger bonding strength.

[0359] High-energy lithium metal batteries

[0360] Using CEE and ACE for 4 mAhcm -2 Rate performance testing of the loaded LiFePO4(LFP) cathode, where the current density ranged from 0.8 mA / cm². -2 Change to 20 mAcm -2 ( Figure 26 ). At 20 mAcm -2 At high currents, ACE retains nearly three times the capacity compared to CEE. When the rate is restored to 2 mAcm... -2 At that time, both electrolytes showed a recovery rate of over 99% of their initial capacity. The high capacity recovery rate in the CEE indicates that the reduced capacity observed at higher current densities is primarily due to limited charge transport kinetics in the electrode-electrolyte interphase. The persistent effect of high-rate cycling on the capacity retention of the LFP was further investigated. Figure 27Upon returning to lower current densities, the CEE exhibited a gradual capacity reduction, eventually dropping to 50% of its initial capacity within 400 cycles. Conversely, the ACE showed a 98.5% capacity retention after 500 cycles. Given the excess Li and electrolyte used in the half-cell configuration, the observed difference is likely related to the increased impedance in the CEE system. Then, by fabricating a battery containing 35 μm Li and 4 mAh cm⁻¹... -2 The electrolyte system under more realistic conditions was evaluated using a full cell with a loaded cathode. At 1C cycling, the Li||LFP cell with ACE exhibited a significant 91% capacity retention after 600 cycles, while the Li||LFP cell with CEE failed within 80 cycles. Figure 28 When the electrolyte (E / C = 5.1 g Ah) -1 When further restricted, Li||LFP cells with CEE fail within 40 cycles, while cells with ACE fail within 161.5 mAhg. -1 No capacity loss was observed within 230 cycles. Figure 29 A 4-V cathode is necessary to achieve higher energy densities. However, in the absence of a stable CEI, free ether solvent molecules react with metal oxides to produce acidic substances, leading to a decrease in cathode capacity. 4.3 V floating tests show that the oxidative instability in CEE is greater than that in ACE. Figure 30 The NCA88 half-cell was then cycled 50 times, with ACE and CEE delivering capacities of 186.7 and 94.7 mAhg, respectively. -1 ( Figure 31 After cycling, CEE exhibited a greater increase in charge transfer impedance compared to ACE. Figure 32 Similarly, galvanostatic intermittent titration identified a significant overpotential growth attributable to ohmic losses in the CEE system, while the ACE system exhibited low overpotentials under different discharge states. Figure 33 Differential capacity (dQ / dV) analysis of the cyclic cathode highlights a significant decrease in the intensity of the H2 to H3 phase transition peak, primarily attributed to the structural collapse of the layered cathode in the CEE system. Figure 34 Using high-resolution transmission electron microscopy (TEM), Figure 35 The structure of the NCA cathode was observed. The instability of the layered NCA structure to the electrolyte led to a phase transition to a rock salt structure. The NCA cathode circulating in ACE exhibited a thin and uniform rock salt layer, while the cathode circulating in CEE had a thick resistive layer. Furthermore, polycrystalline domains were observed on the surface of the cathode circulating in CEE, which was confirmed by multiple arcs indicating the rock salt structure with stretched diffraction spots in the Fourier transform image. Figure 35a). These findings suggest that the collapse of the thick, non-conductive CEI and NCA structure together contributes to the capacity reduction in the NCA cathode during cycling in the CEE. XPS depth profiling analysis was performed on the NCA88 cathode to better understand the post-cycling CEI chemistry. Figure 36 Elemental analysis revealed high levels of carbonaceous materials derived from PVDF in both electrolyte systems (287.4 and 289.9 eV). Figure 37 a). CC and CO substances, possibly derived from ether solvents, are more pronounced in NCA particles cycled with CEE. O1s spectra from cathodes cycled with ACE show a consistent composition across various depths with smaller SOx and NOx peaks (534 eV), which can be attributed to salt decomposition at the CEI. Figure 37 b). The high MO bond signal (530 eV) in the CEE system indicates that it cannot effectively passivate the active cathode surface. Conversely, ACE provides sufficient protection for the NCA cathode. (0.8 to 20.0 mA cm⁻¹) -2 At current density, for NCA88 (4 mAhcm) -2 The rate performance of the half-cell was tested. Figure 38 ). At 20 mAcm -2 At high current densities, NCA cells with CEE completely fail, while cells with ACE maintain 70 mAh / g. -1 The capacity. Recovering to 2 mAcm -2 At high current densities, the cathode with ACE recovered its original capacity, while the cell with CEE continued to lose capacity, experiencing a 36.2% capacity loss after high-rate testing.

[0361] Performance of lithium metal and anode-free all-cell batteries

[0362] A 50μm thick LMA was mixed with 2 mAh cm⁻¹ -2 The load is paired with NCA88 cathodes to manufacture the entire cell. Figure 39 a and Figure 40 The full-cell battery with CEE failed to provide any measurable capacity after 100 cycles, and significant CE fluctuations were observed throughout the cycle. Figure 41 In stark contrast, cells with ACE maintained an average retention of 80% after 250 cycles. Furthermore, a sharp increase in polarization was observed in cells with CEE compared to the stable and steady-state polarization observed in ACE. Figure 42 The study evaluated the effects of a 35 μm thick Li layer with a low E / C ratio (5.1 g Ah) under more realistic conditions. -1 ) high-load cathode (4 mAhcm) -2The entire cell, composed of N / P ratio = 1.75, consists of... Figure 39 b). Full cells with CEE degraded rapidly and eventually failed at the 32nd cycle. Figure 43 Conversely, the ACE-based cells exhibited robust performance, retaining 82.4% (159.3 mAh g) of their initial capacity after 150 cycles. -1 Then the study investigated the effects under electrolyte-poor conditions (5.1 g Ah). -1 ) below 2mAhcm -2 Cycle performance of NCA-88 cathode-coupled anode-free (Cu||NCA-88) cells Figure 39 c). Anode-free all-cell batteries employing CEE experienced a sharp initial decrease in capacity and significant CE fluctuations. Figure 44 The limited performance of CEE can be attributed to the linear slope in its voltage curve, which indicates the limited ion transport dynamics within the cell. Figure 45 Conversely, batteries with ACE achieved a 59% capacity retention rate after 100 cycles, demonstrating enhanced performance. The performance of LMBs with ACE is consistent with existing electrolyte design strategies, including WSE, LHCE, and FFE. Figure 39 d). In addition to these technical advantages, the simplicity and cost-effectiveness of ACE manufacturing offer a significant economic advantage over alternative electrolyte design strategies. Figure 39 e and Figure 39 f), as summarized in Tables 1-4 below.

[0363] [Table 1]

[0364] Physicochemical properties and standardized costs of different solvents and diluents

[0365] [Table 2]

[0366] Physicochemical properties and standardized costs of different salts

[0367] [Table 3]

[0368] Comparison of Li||Cu coulombic efficiency in existing technologies

[0369] [Table 4]

[0370] Comparison of the performance of existing Li metal batteries

[0371] Experiment 2

[0372] This method develops an electrolyte with enhanced interfacial stability, called tetrabutylammonium tetrafluoroborate (TBATFB) electrolyte, which is specifically targeted at the sensitivity of Li metal anodes and high-voltage cathodes through additive modification. By incorporating the TBATFB additive, this exemplary method addresses the inherent challenges of each electrode, thereby enabling high-energy lithium metal batteries to operate in a stable and cost-effective manner.

[0373] To obtain a baseline electrolyte, 1 M lithium bis(fluorosulfonyl)imide (LiFSI) was dissolved in anhydrous THF (Comparative Example 2). To investigate additives, 0.1 M (Example 7), 0.5 M (Example 8), and 1.0 M (Example 9) of TBATFB were introduced into a 1 M LiFSI / THF electrolyte and designated as 0.1 M TBATFB, 0.5 M TBATFB, and 1.0 M TBATFB, respectively.

[0374] Testing the electrochemical properties of TBATFB electrolyte

[0375] The ionic conductivity of the electrolyte is a fundamental characteristic of battery performance because it enables efficient charge transport. Figure 46 The measured ionic conductivity values ​​of the electrolytes are displayed. 0.1 MTBATFB exhibits the highest conductivity (5.0 mS / cm). -1 ), followed by baseline electrolyte (4.4 mS / cm). -1 ), 0.5MTBATFB24 (4.1mScm) -1 ) and 1.0MTBATFB (2.9mScm -1 The 0.5 M and 1.0 M TBATFB electrolytes exhibited lower ionic conductivity, most likely due to increased electrolyte viscosity.

[0376] Next, the transfer number (t+) is evaluated to determine the efficiency of lithium-ion transport. Figure 37 The baseline electrolyte exhibited a low t+ value of 0.34, typical for conventional electrolytes. In contrast, adding TBATFB increased the t+ values ​​to 0.57, 0.53, and 0.53 for 0.1 M, 0.5 M, and 1.0 M TBATFB, respectively. The t+ value of 0.1 M TBATFB was slightly higher than that of 0.5 M and 1.0 M TBATFB, primarily due to the increased ionic conductivity of the electrolyte resulting from the reduced viscosity. The enhanced electrochemical kinetics at the electrode / electrolyte interface (where dynamic redox reactions occur) were facilitated by the high ionic conductivity and t+ value, and improved the performance of Li metal batteries.

[0377] Study on the reversibility and reduction stability of Li

[0378] The stability of Li metal batteries depends on the compatibility between the electrolyte and Li metal. Li reversibility is demonstrated by a 1 mAcm... -2 and 1 mAhcm -2 The coulombic efficiency of the Li||Cu asymmetric cell is measured below. Figure 48 a) The baseline electrolyte exhibited unstable Li plating and stripping behavior with a low average coulombic efficiency (CE) of 93.0%. Conversely, the addition of TBATFB salt showed a sharp increase in average CE (98.5% for 0.1 MTBATFB, 98.3% for 0.5 MTBATFB, and 96.7% for 1.0 MTBATFB). To determine Li loss without the influence of the Cu substrate, at 0.5 mAcm -2 and 0.5 mAhcm -2 Below, at 5.0 mAhcm -2 The library capacity is implemented using the Aurbach scheme ( Figure 48 (b) The baseline electrolyte maintained a low CE of 92.4%. 0.5 M TBATFB and 1.0 M TBATFB showed increased CEs, at 94.1% and 93.7%, respectively. In stark contrast, 0.1 M TBATFB showed higher reversibility with a CE of 97.8%.

[0379] To gain further insight into the stability of the solid-electrolyte interface (SEI), passivation stability was measured. Passivation stability was tested in a Li||Cu asymmetric cell while maintaining 0.0V (relative to Li / Li). + Simultaneously, the leakage current was measured for 10 hours. Figure 49 The results showed that the baseline electrolyte exhibited a significantly higher leakage current (3.08 μA) compared to the electrolyte containing TBATFB (0.22 to 0.69 μA), indicating that the SEI was less effective in completely passivating the fragile Li metal anode. Furthermore, the stability of the SEI increased with increasing TBATFB content, suggesting that TBATFB actively contributes to the initial SEI formation process. Based on these results, TBATFB can effectively enhance the interfacial stability of the Li metal anode and has improved overall electrolyte performance.

[0380] Oxidative stability determination

[0381] Single-crystal LiNi was selected 0.88 Co 0.09 Al 0.03 O2 (NCA-88) was used as a high-voltage cathode to determine the oxidative stability of the modified electrolyte. When the cell was at 4.3V (relative to Li / Li...)... + When the voltage is maintained at a constant voltage for 20 hours, a floating test is performed to measure the leakage current. Figure 50 The baseline electrolyte failed to maintain stability at a fixed potential, resulting in a steady increase in leakage current over time. In contrast, the 0.1 MTBATFB electrolyte exhibited leakage current indicating fewer side reactions occurring at the cathode-electrolyte interphase (CEI). The modified electrolyte achieved a minimum leakage current of 11 μA, reflecting a fully passivated cathode surface.

[0382] Electrochemical performance distribution of Li metal batteries tested under stringent conditions

[0383] To maximize the energy density of the entire cell, a thin Li (35 μm) layer is combined with a high-load cathode (20 mg / cm²). -2 Paired with low N / P ratio (1.75) and E / C ratio (5gAh) -1 ()( Figure 51 The baseline electrolyte exhibited a sharp decline in capacity, recording 50% capacity retention within the first 20 cycles before the cell failed completely within the next 10 cycles. In contrast, the 0.1MTBATFB electrolyte provided improved cycle stability, achieving 91% capacity retention after 100 cycles.

[0384] The above experiments demonstrate the effectiveness of the electrolyte of this disclosure in improving the stability of the electrode-electrolyte intermediate phase in ether-based electrolytes. Results show that the addition of TBATFB salt to the ether-solvent electrolyte significantly improves various key parameters, including CE, LMA passivation stability, exchange current density, and Li. + The electrolyte exhibits ion selectivity while maintaining the high ionic conductivity inherent in ether electrolytes. The durability and stability imparted by the electrolyte of this disclosure extend the cycle life of higher-performance LMBs under real-world conditions. Furthermore, these results demonstrate that the strategy employing the electrolyte of this disclosure provides a cost-effective solution for stabilizing the electrode-electrolyte interphase without requiring a custom electrolyte solvation structure. This strategy effectively addresses several fundamental interfacial challenges and performance limitations associated with secondary batteries.

[0385] Those skilled in the art will understand that various aspects of the invention can be practiced within a wide range of equivalent parameters without affecting the scope of the invention described herein. All publications, patent applications, and patents disclosed herein are incorporated herein by reference in their entirety.

Claims

1. An electrolyte composition for a secondary battery, the electrolyte composition comprising: Electrolyte compounds; fluorinated quaternary ammonium compounds; and Solvent.

2. The electrolyte composition of claim 1, wherein, The solvent contains an ether compound.

3. The electrolyte composition according to claim 2, wherein, The ether compound comprises at least one selected from the group consisting of tetrahydrofuran (THF), ethylene carbonate (EC), diethyl ether (DEE), 1,3-dioxolane (DOL), 1,2-dimethoxyethane (DME), dicyclohexyl ether, tetraethylene glycol dimethyl ether (TEGDME), 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (TTTE), fluorinated 1,6-dimethoxyhexane (FDMH), 1,2-bis(2,2-difluoroethoxy)-ethane (F4DEE), 2-methyltetrahydrofuran, dimethyltetrahydrofuran, dimethoxytetrahydrofuran, ethoxytetrahydrofuran, dihydropyran, tetrahydropyran, furan, and 2-methylfuran.

4. The electrolyte composition of claim 3, wherein, The ether compounds include tetrahydrofuran (THF).

5. The electrolyte composition of claim 1, wherein, The electrolyte compound includes at least one selected from the group consisting of lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LTFSI), LiPF6, LiAsF6, LiBF4, LiCF3SO3, and LiClO4.

6. The electrolyte composition of claim 5, wherein, The electrolyte compound includes lithium bis(fluorosulfonyl)imide (LiFSI).

7. The electrolyte composition of claim 1, wherein, The fluorinated quaternary ammonium compounds include tetrabutylammonium tetrafluoroborate (TBATFB).

8. The electrolyte composition of claim 1, wherein, The electrolyte compound and the fluorinated quaternary ammonium compound are contained in the electrolyte composition in a molar ratio of 10:0.01 to 0.1:

5.

9. The electrolyte composition of claim 1, wherein, The electrolyte compound and the fluorinated quaternary ammonium compound are contained in the electrolyte composition in a molar ratio of 1:0.1 to 1:

1.

10. A secondary battery comprising the electrolyte composition of claim 1.

11. A secondary battery, comprising: positive electrode; negative electrode; and The electrolyte composition comprises lithium bis(fluorosulfonyl)imine (LiFSI), tetrabutylammonium tetrafluoroborate (TBATFB), and tetrahydrofuran (THF).

12. The secondary battery as claimed in claim 11, wherein, The lithium bis(fluorosulfonyl)imide (LiFSI) and the tetrabutylammonium tetrafluoroborate (TBATFB) are contained in the electrolyte composition in a molar ratio of 1:0.1 to 1:

1.

13. The secondary battery as claimed in claim 11, wherein, The secondary battery has a coulombic efficiency of greater than 95% after at least 200 cycles.

14. The secondary battery as claimed in claim 11, wherein, The secondary battery has a specific capacity greater than 100 mAh / g at a charge / discharge rate of C / 5 to 1C for at least 100 cycles.

15. The secondary battery as claimed in claim 11, wherein, The secondary battery has a capacity retention of more than 90% after at least 500 cycles at a charge / discharge rate of C / 5 to 1C.

16. The secondary battery as claimed in claim 11, wherein, The positive electrode is configured to embed Li. + ions or Na + ion.

17. An electric vehicle comprising the secondary battery of claim 11.

18. A method for preparing a secondary battery, the method comprising: Forming an electrode assembly including a positive and a negative electrode; and An electrolyte composition is injected into the electrode assembly, the electrolyte composition comprising: an electrolyte compound, a fluorinated quaternary ammonium compound, and a solvent.

19. The method of claim 18, wherein, The electrolyte compound and the fluorinated quaternary ammonium compound are contained in the electrolyte composition in a molar ratio of 10:0.01 to 0.1:

5.

20. The method of claim 18, wherein, The electrolyte compound includes lithium bis(fluorosulfonyl)imide (LiFSI); The fluorinated quaternary ammonium compound includes tetrabutylammonium tetrafluoroborate (TBATFB); and The solvent includes tetrahydrofuran (THF).

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