Electrode materials with mixed particle sizes

Abstract

The present invention relates to electrochemical devices and materials thereof. More specifically, embodiments of the present invention provide a low porosity electrode comprising large particles and small particles. The large particles comprise electrochemically active materials. The small particles comprise ion-conducting electrolyte materials. In some embodiments, the large particles and small particles are characterized by a dispersion not greater than 0.5. And other embodiments.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 007,416, filed on June 4, 2014, and entitled “ELECTRODE MATERIALS WITH MIXED PARTICLE SIZES,” which is hereby incorporated by reference in its entirety for all purposes. Background of the Invention

[0003] The present disclosure relates to electrochemical devices and electrochemical materials thereof. In particular, the present disclosure relates to some challenges regarding electrochemical electrode preparation and nano-sized electrode filling structures and / or solid-state electrodes.

[0004] With the widespread popularity of consumer electronics (such as mobile phones, tablets, and laptops) and electric vehicles (such as plug-in hybrid vehicles and electric vehicles), there is an urgent need for better power storage devices to drive automobiles and electronic products. Although rechargeable (secondary charging / traction) lithium (Li) ion batteries (i.e., Li rechargeable batteries) have been widely used in consumer electronics, they are limited in energy density and output power, which has prevented traditional batteries from being widely used in other application areas (such as the automotive industry). Solid-state lithium rechargeable batteries, which are composed of all solid components, have higher energy density and power output, and have great potential as a replacement for traditional batteries that rely on and contain liquid electrolytes.

[0005] The ionic conductivity in the solid phase is generally lower than that in the liquid phase. Therefore, in order to achieve higher power output in solid-state batteries, all ion conduction channels should pass through the solid, the ion channels should be reduced, and the intrinsic ionic conductivity constituting the solid part should be increased. Despite substantial efforts, these problems have not been corrected, and solid-phase batteries still have low power output.

[0006] Therefore, there are still a series of problems in the related fields involving solid-state electrochemical electrodes (such as thin film positive electrodes) and in the form of nanostructures and nanoscale components (such as active materials and cathode electrolytes). For example, what is needed in these related fields is a method for preparing new thin film positive electrodes, which include specific dimensional features required for high-efficiency solid-state batteries. In addition to taking and using the same solutions and other solutions to related problems in the related fields, the present invention partially illustrates such nanostructures and nanoscale positive electrodes. Summary of the Invention

[0007] In one embodiment, the solid-state electrochemical electrode provided by the present invention comprises a first plurality of particles of an electrochemically active material, the first particles having a first particle size distribution characterized by a first dispersity of 0.25 or less and a first median diameter; and a second plurality of particles of an ion conductive material, the second particles having a second particle size distribution characterized by a second dispersity of 0.25 or less and a second median diameter; the second median diameter being 1 / 3 or less of the first median diameter.

[0008] In a second embodiment, the solid-state electrochemical electrode provided by the present invention comprises: an active material characterized by a first particle size distribution having a first median particle size; a cathode electrolyte material characterized by a second particle size distribution having a second median particle size; wherein the volume ratio of the active material to the cathode electrolyte material is from 99:1 to 1:1; and wherein the particle size ratio of the first median particle size to the second median particle size is at least 3:1 or greater.

[0009] In a third embodiment, the electrochemical cell provided by the present invention comprises: an anode current collector; an anode in direct contact with the anode current collector; an electrolyte in direct contact with the anode, the anode being located between the anode current collector and the electrolyte, and the electrolyte being characterized by an ionic conductivity of at least 1e-4 S / cm; and a solid positive electrode in direct contact with the electrolyte, the solid positive electrode comprising: an active material characterized by a first particle size distribution having a first median particle size; a cathode electrolyte material characterized by a second particle size distribution having a second median particle size; wherein the volume ratio of the active material to the cathode electrolyte material is from 99:1 to 1:1; and wherein the particle size ratio of the first median particle size to the second median particle size is at least 3:1 or greater.

[0010] In fourth and fifth embodiments, the present invention provides methods for making and using the electrochemical electrodes described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 An electrode embodiment having active material and catholyte particles of mixed particle sizes is shown.

[0012] Figure 2 An electrode embodiment having active material and catholyte particles of mixed particle sizes is shown.

[0013] Figure 3 An embodiment of a percolating network of catholyte material in a solid-state cathode is shown.

[0014] Figure 4 Example showing the particle size (diameter) ratio of large particle size to small particle size as a function of the percolation threshold for a randomly packed electrode having particles of active material (large particles) and catholyte (small particles) of mixed size.

[0015] Figure 5 An example of a functional relationship between the particle size ratio of large particle size to small particle size and the percolation threshold of a compressed packed electrode is shown.

[0016] Figure 6 The particle size ratio representing the large particle size to the small particle size is expressed as a function of the random packing density.

[0017] Figure 7 Represents the total container volume fraction occupied by small particles in the large and small particle clusters in the electrode renormalized by the percolation threshold.

[0018] Figure 8 It represents the functional relationship between the volume of small particles in electrodes with large and small particle sizes and the 2D cross-sectional area fraction occupied by small particles.

[0019] Fig. 9 Figure 5 shows the electrode percolation threshold at 2% compression as a function of the normalized 2D cross-sectional area fraction.

[0020] Fig.10 Represents the fraction of small particles as a function of the fraction of large particles that contact the penetrating particle.

[0021] Fig.11 SEM images showing electrode materials with large and small particles that have not been firmly compressed. The large particles (1102) are nickel cobalt aluminum oxide (NCA), and the small particles (1101) are LSTPS sulfide electrolyte.

[0022] Fig.12 SEM images of electrode materials showing large and small particles that have undergone a compression process. The large particles (1202) are nickel cobalt aluminum oxide (NCA), and the small particles (1201) are LSTPS sulfide electrolyte.

[0023] Fig.13 An embodiment of a positive electrode device having a large particle cathode active material, a small particle catholyte ion conductor forming a percolating network, and an electron conductor additive is shown.

[0024] Fig.14 An embodiment of a cathode filling structure is shown, in which either monodisperse large-size particles are mixed with Gaussian-distributed small-size particles (left), or Gaussian-distributed large-size particles are mixed with Gaussian-distributed small-size particles (right), wherein in either case the diameter ratio of the large to small particles is 4.

[0025] Fig.15An embodiment of a cathode filling structure is shown, in which either monodisperse large-size particles are mixed with monodisperse small-size particles (left side), in which case the ratio of the large particle size (diameter) to the small particle size is 4; or monodisperse large-size particles are mixed with monodisperse small-size particles (right side), in which case the ratio of the large particle size (diameter) to the small particle size is 2.

[0026] Fig.16 The distribution graph of the particle size ratio of large and small particles and conductivity for three cathode embodiments in which the particle size ratio of large particle size (oxide) to small particle size (sulfide cathode electrolyte) is 20:1, 5:1, and 1:1 respectively. In each sample, the volume ratio of large particle size (oxide) to small particle size (sulfide cathode electrolyte) is 80:20.

[0027] Fig.17 Indicates large particle size (Al 2 O 3 Scanning electron microscope (SEM) image of a cathode embodiment having a particle size ratio of 20:1 between large particle size (LSTPS sulfide cathode electrolyte) and small particle size (LSTPS sulfide cathode electrolyte).

[0028] Fig.18 Scanning electron microscope (SEM) image showing a cathode embodiment having a 20:1 ratio of large particle size (alumina) to small particle size (LSTPS sulfide catholyte).

[0029] Fig.19 Indicates large particle size (Al 2 O 3 ) to small particle size (LSTPS sulfide cathode electrolyte) with a particle size ratio of 5:1.

[0030] Fig. 20 Indicates large particle size (Al 2 O 3 ) to small particle size (LSTPS sulfide cathode electrolyte) with a particle size ratio of 5:1.

[0031] Fig.21 Indicates large particle size (Al 2 O 3 ) and small particle size (LSTPS sulfide cathode electrolyte) with a particle size ratio of 1:1.

[0032] Fig. 22 Indicates large particle size (Al 2 O 3 ) and small particle size (LSTPS sulfide cathode electrolyte) with a particle size ratio of 1:1.

[0033] Fig.23 Indicates large particle size (Al 2 O 3 ) and small particle size (LSTPS sulfide cathode electrolyte) with a particle size ratio of 20:1, wherein the large particle size (Al 2 O 3 The weight ratio of large particle size (LSTPS sulfide cathode electrolyte) to small particle size (LSTPS sulfide cathode electrolyte) is 80:18.

[0034] Fig.24 Indicates large particle size (Al 2 O 3 ) and small particle size (LSTPS sulfide cathode electrolyte) with a particle size ratio of 20:1, where the large particle size (Al 2 O 3 The weight ratio of large particle size (LSTPS sulfide cathode electrolyte) to small particle size (LSTPS sulfide cathode electrolyte) is 44:54.

[0035] Fig.25 The LSTPS and Al after grinding used in the examples of the present invention are shown in FIG. 2 O 3 Example of particle size distribution.

[0036] Fig.26 Shown are examples of particle size distribution of LSTPS and NCA after grinding used in examples of the present invention.

[0037] Fig. 27 A graph showing the functional relationship between the cathode electrolyte volume fraction and conductivity for different ratios of large and small particle sizes.

[0038] Detailed description of the invention

[0039] The following is intended to enable one of ordinary skill in the art to adopt and use the examples and paradigms provided herein, and to refer to the same in connection with specific applications. Various modifications and uses in different applications will be readily recognized by those skilled in the art, and the general principles defined herein can be applied to a wide range of embodiments. Therefore, the present invention is not limited to the embodiments reported, but is intended to be consistent with the principles and novelties reported herein to the greatest extent possible.

[0040] The reader's attention is directed to all papers and documents filed concurrently with this specification and open to public inspection with this specification, the contents of all such papers and documents are incorporated herein by reference. Unless expressly stated otherwise, each feature disclosed is only an example of a generic series of equivalent or similar features.

[0041] In addition, any feature in a claim, if not explicitly defined as a “meaning” for performing a specific function, or a “step” for performing a specific function, should not be interpreted as a “meaning” or “step” in accordance with the description in 35 U.S.C. §112(f). Specifically, the “step” or “act” used in the claims of the present invention is not intended to invoke the provisions of 35 U.S.C. §112(f).

[0042] Please note that if used, the marks left, right, front, back, top, bottom, forward, reverse, clockwise and counterclockwise are only used for convenience of description and are not intended to imply any particular fixed direction. Instead, they are used to reflect the relative position and / or direction between the parts of a thing.

[0043] I. Definitions

[0044] As used herein, the phrase "at least one molecule selected from the group" includes a single molecule from the group, more than one molecule from the group, or a combination of molecules from the group. At least one molecule selected from the group consisting of A, B, and C includes, for example, only A, only B, or only C, and A and B, and A and C, and B and C, and A, B, and C, or any other combination of A, B, and C.

[0045] As used herein, the phrase "electrochemical cell" refers to, for example, a "battery" comprising a positive electrode, a negative electrode, and an electrolyte, wherein the electrolyte is between the positive and negative electrodes and in direct contact with and conducts ions (e.g., Li + ) conduction while maintaining electrical insulation between the positive and negative electrodes. In some examples, the battery can include multiple positive electrodes and / or multiple negative electrodes enclosed in a container.

[0046] As used herein, the phrase "positive electrode" refers to a positive electrode in a secondary battery, such as a cation such as Li + , an electrode that approaches, guides, flows toward, or moves toward during battery discharge. The phrase "negative electrode" used in the present invention refers to the electrode in a secondary battery, from which cations such as Li + , the electrode to which the charge flows or moves during battery discharge. In a battery consisting of a Li-metal electrode and a conversion chemical electrode (i.e., an active material; e.g., NiF x ) in a battery composed of a cathode, the electrode with the conversion chemical material is called a positive electrode. In some conventional usages, the cathode is used instead of the positive electrode, and the anode is used instead of the negative electrode. When the Li secondary battery is charged, Li ions move from the positive electrode (such as NiFx) to the negative electrode (such as Li-metal). When the Li-secondary battery is discharged, Li ions move from the negative electrode to the positive electrode.

[0047] As used herein, the phrase "sulfide electrolyte" refers to a conductive Li + ions while remaining sufficiently electrically insulating. Some sulfide electrolytes described in the present invention include lithium, phosphorus, and sulfur and optionally 1, 2, or 3 additional elements. The sulfide electrolyte is referred to as LXPS material, wherein L refers to lithium, P refers to phosphorus, and S refers to sulfur, and X refers to the optional 1, 2, or 3 additional elements. Examples of LXPS materials that have been discovered, for example, are described in a paper entitled “SOLIDSTATE CATHOLYTE OR ELECTROLYTE FOR BATTERY USING LXPS” filed on May 15, 2014. A MP B S C or, U.S. Patent No. 8,697,292 filed by Kanno et al., the entire contents of both of which are incorporated herein by reference for all purposes.

[0048] As used herein, the phrase “sulfide electrolyte” includes, but is not limited to, LSS, LTS, LXPS, LXPSO, wherein X is Si, Ge, Sn, As, Al; LATS; and S is S, Si, or a combination thereof; and T is Sn.

[0049] As used herein, "LXPS" refers to a cathode electrolyte material characterized by a general formula of Li a MP b S c , wherein M is Si, Ge, Sn and / or Al, and wherein 2≤a≤8, 0.5≤b≤2.5, 4≤c≤12. "LSPS" refers to an electrolyte material characterized by the general formula L a SiP b S c , where 2≤a≤8, 0.5≤b≤2.5, 4≤c≤12. LSPS refers to an electrolyte material characterized by the general formula L a SiP b S c , where 2≤a≤8, 0.5≤b≤2.5, 4≤c≤12, d<3. Examples of LXPS materials that have been discovered are, for example, in a paper entitled “SOLID STATE CATHOLYTE OR ELECTROLYTE FOR BATTERY USING LI A MP B S C” (M=Si, Ge and / or Sn) in International Patent Application No. PCT / US2014 / 038283, which is hereby incorporated by reference in its entirety. When M is Sn and Si - both of which are present - the LXPS material is referred to as LSTPS. As used herein, “LSTPSO” refers to LSTPS doped with or containing O. In some embodiments, “LSTPSO” refers to a material of LSTPS having an oxygen content between 0.01 and 10 atomic %. “LSPS” refers to an electrolyte material containing a chemical composition of Li, Si, P and S. As used herein, “LST "PS" refers to an electrolyte material containing the chemical composition of Li, Si, P, Sn, and S. As used in the present invention, "LSPSO" refers to a LSPS doped with or containing O. In some embodiments, "LSPSO" is a LSPS material containing oxygen between 0.01 and 10 atomic %. "LATP" as used in the present invention refers to an electrolyte material containing the chemical composition of Li, As, Sn, and P. "LAGP" as used in the present invention refers to an electrolyte material containing the chemical composition of Li, As, Ge, and P. "LXPSO" as used in the present invention refers to a cathode electrolyte material characterized by a general formula of Li a MP b S c O d , wherein M is Si, Ge, Sn, and / or Al, and wherein 2≤a≤8, 0.5≤b≤2.5, 4≤c≤12, d<3. LXPSO refers to LXPS, as described above, which is doped with from 0.1 to about 10 atomic % oxygen. LPSO refers to LPS, as described above, which is doped with from 0.1 to about 10 atomic % oxygen.

[0050] As used herein, "LSS" refers to lithium silicon sulfide, which can be described as Li 2 S-SiS 2 、Li-SiS 2 , Li-S-Si and / or a cathode electrolyte consisting essentially of Li, S and Si. LSS refers to an electrolyte material characterized by the general formula Li x Si y S z , wherein 0.33≤x≤0.5, 0.1≤y≤0.2, 0.4≤z≤0.55, and it may contain up to 10 atomic % of oxygen. LSS also refers to an electrolyte material including Li, Si and S. In some embodiments, LSS is Li 2 S and SiS 2 In some embodiments, Li 2 S:SiS 2The molar ratio of said ratio is 90:10, 85:15, 80:20, 75:25, 70:30, 2:1, 65:35, 60:40, 55:45, or 50:50. LSS can be doped with the following compounds: Li x PO y 、Li x BO y 、Li 4 SiO 4 、Li 3 MO 4 、Li 3 MO 3 、PS x 、and / or lithium halides such as, but not limited to, LiI, LiCl, LiF or LiBr, where 0 < x ≤ 5 and 0 < y ≤ 5.

[0051] As used in the present invention, "LTS" refers to lithium tin sulfide, which can be described as Li 2 S-SnS 2 、Li 2 S-SnS、Li-S-Sn、and / or a cathode electrolyte consisting essentially of Li, S and Sn. The composition can be Li x Sn y S z ,where 0.25 ≤ x ≤ 0.65, 0.05 ≤ y ≤ 0.2, and 0.25 ≤ z ≤ 0.65. In some embodiments, LTS is a mixture of Li 2 S and SnS 2 with a molar ratio of 80:20, 75:25, 70:30, 2:1, or 1:1. LTS can contain up to 10 atomic % oxygen. LTS can be doped with Bi, Sb, As, P, B, Al, Ge, Ga, and / or In. As used in the present invention, "LATS" refers to LTS, as described above, which further contains arsenic (As). In LATS, L refers to lithium, A refers to arsenic, T refers to tin, and S refers to sulfur.

[0052] As used in the present invention, "LPS" refers to an electrolyte containing the chemical elements Li, P, and S. As used in the present invention, "LPSO" refers to LPS doped with oxygen or containing oxygen. In some embodiments, "LPSO" is an LPS material with an oxygen content between 0.01 and 10 atomic %. LPS refers to an electrolyte material characterized by the general formula Li x P y S z ,where 0.33 ≤ x ≤ 0.67, 0.07 ≤ y ≤ 0.2 and 0.4 ≤ z ≤ 0.55. LPS also refers to an electrolyte characterized by being composed of Li 2 S:P 2S 5 The mixed product, wherein the molar ratio is 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1, 7:3, 2:1, or 1:1. LPS also refers to an electrolyte, characterized in that Li 2 S:P 2 S 5 A product composed of a mixture wherein the reactant or precursor has Li 2 The amount of S is 95 atomic%, and P 2 S 5 is 5 atomic %. LPS also refers to an electrolyte, which is characterized by Li 2 S:P 2 S 5 A product composed of a mixture wherein the reactant or precursor has Li 2 The amount of S is 90 atomic %, and P 2 S 5 is 10 atomic %. LPS also refers to an electrolyte, which is characterized by Li 2 S:P 2 S 5 A product composed of a mixture wherein the reactant or precursor has Li 2 The amount of S is 85 atomic %, and P 2 S 5 is 15 atomic %. LPS also refers to an electrolyte, which is characterized by Li 2 S:P 2 S 5 A product composed of a mixture wherein the reactant or precursor has Li 2 The amount of S is 80 atomic %, and P 2 S 5 is 20 atomic %. LPS also refers to an electrolyte, which is characterized by Li 2 S:P 2 S 5 A product composed of a mixture wherein the reactant or precursor has Li 2 The amount of S is 75 atomic %, and P 2 S 5 is 25 atomic %. LPS also refers to an electrolyte, which is characterized by Li 2 S:P 2 S 5 A product composed of a mixture wherein the reactant or precursor has Li 2 The amount of S is 70 atomic %, and P 2 S 5 is 30 atomic %. LPS also refers to an electrolyte, which is characterized by Li 2 S:P 2 S 5 A product composed of a mixture wherein the reactant or precursor has Li 2The amount of S is 65 atomic %, and P 2 S 5 is 35 atomic %. LPS also refers to an electrolyte, which is characterized by Li 2 S:P 2 S 5 A product composed of a mixture wherein the reactant or precursor has Li 2 The amount of S is 60 atomic %, and P 2 S 5 It is 40 atomic %.

[0053] As used in the present invention, LPSO refers to the electrolyte material as described above, characterized in that the general formula is Li x P y S z O w , wherein 0.33≤x≤0.67, 0.07≤y≤0.2, 0.4≤z≤0.55, 0≤w≤0.15. In addition, LPSO refers to LPS, as described above, which contains an oxygen content from 0.01 to 10 atomic %. In some embodiments, the oxygen content is 1 atomic %. In some other embodiments, the oxygen content is 2 atomic %. In some other embodiments, the oxygen content is 3 atomic %. In some embodiments, the oxygen content is 4 atomic %. In some other embodiments, the oxygen content is 5 atomic %. In some other embodiments, the oxygen content is 6 atomic %. In some embodiments, the oxygen content is 7 atomic %. In some other embodiments, the oxygen content is 8 atomic %. In some other embodiments, the oxygen content is 9 atomic %. In some embodiments, the oxygen content is 10 atomic %.

[0054] As used herein, the term "necked" or "necked" refers to the connectivity of particles to particles in, for example, a solid solution, a polymer, a solid matrix or a solvent matrix. As the electrolyte particles are necked, the particles are all in sufficient contact to provide ion conduction pathways from particle to particle and through the particles, via the particle to particle contact or shared surfaces. Necks can include sintering together, face sharing, edge sharing, corner sharing, or otherwise bonding together, and forming a percolating network when compounded with a polymer, solvent, or other solid component.

[0055] As used herein, the term "dispersity" refers to the breadth of the particle size distribution, which can be measured by standard methods such as dynamic light scattering. Mathematically, the particle distribution is approximated by a log-normal distribution. Wherein, σ is the distribution dispersity. In the present application, the dispersity measurement expressed as a numerical term refers to the dispersity of the best-fit lognormal distribution of the experimentally determined particle size distribution. The dispersity value (σ) can be calculated by the above formula.

[0056] As used herein, the term "sulfide-based electrolyte" refers to an electrolyte comprising an inorganic material containing S, wherein the inorganic material containing sulfur conducts ions (e.g., Li + ) and electrical insulation of positive and negative electrodes for electrochemical cells (e.g., secondary batteries). Examples of sulfide-based electrolytes are as described above, such as LXPS, LSTPS, LPSO, and related sulfides. Examples of sulfide-based electrolytes are reported in the following patents: SOLID STATECATHOLYTE OR ELECTROLYTE FOR BATTERY USING LI A MP B S C The international PCT patent application number for (M=SI, GE, AND / OR SN) is PCT / US14 / 38283, the publication number is WO 2014 / 186634, and the publication date is November 20, 2014.

[0057] As used herein, the phrase "solid-state cathode electrolyte," or the term "catholyte," refers to an ionic conductor that is intimately mixed with, or encapsulated by, a cathode (i.e., positive electrode) active material (e.g., a metal fluoride, preferably lithium, lithium cobalt oxide, or lithium manganese cobalt oxide, or lithium nickel aluminum cobalt oxide).

[0058] As used herein, the term "nanostructured" or "nanosized" refers to a composite material wherein the constituent components are separated in nanosized form. For example, a nanosized composite material may include a Li-containing compound, such as LiF, and an Fe-containing compound, such as Fe, wherein the domains of the Fe and the domains of the LiF have a median physical size of about 1-100 nm, or 2-50 nm, or 1-10 nm, or 2-5 nm, or 5-15 nm, or 5-20 nm, or the like, which size can be measured by visually comparing different nanodomains to identify TEM micrographs.

[0059] As used in the present invention, the term "electrolyte" refers to a material that is used for ion conduction and can be electrically insulating. The electrolyte can be used to electrically insulate the positive and negative electrodes of the secondary battery while allowing ions to be conducted through the electrolyte, such as: Li + .

[0060] As used herein, the term "anolyte" refers to an ion-conducting material that is mixed with, layered with, or stacked on an anode material or an anode current collector.

[0061] As used herein, the term "green film" refers to an unsintered film comprising at least one molecule selected from garnet material, a precursor of garnet material, a binder, a solvent, carbon, a dispersant, or a combination thereof.

[0062] The term "manufacturing" as used herein refers to the process or method of forming or causing the formation of the manufactured object. For example, manufacturing an energy storage electrode includes the process, process steps, or method that leads to the formation of the electrode of the energy storage device. The final result of the steps of manufacturing the energy storage electrode is to produce a material that can be used as an electrode.

[0063] The phrase "energy storage electrode" used in the present invention refers to, for example, an electrode suitable for use in an energy storage device, such as a lithium rechargeable battery or a Li-secondary battery. As used in the present invention, such electrodes, as functional components for charging and discharging rechargeable batteries, have the necessary ability to conduct electrons and Li ions.

[0064] As used herein, the phrase "providing" means providing, producing or, presenting, or delivering what is provided.

[0065] The phrase "conductive additive" as used herein refers to a material that is mixed with the cathode active material to improve the conductivity of the cathode. Examples include, but are not limited to, carbon and various forms of carbon, such as Ketjen black, VGCF, acetylene black, graphite, graphene, carbon nanotubes, carbon nanofibers, the like, and combinations thereof.

[0066] As used herein, the phrase "applying pressure" refers to a process in which pressure is generated on another material by an external device, such as a calender or a uniaxial machine.

[0067] The term "about" used in the present invention refers to the limitation of the quantity associated with the word about. In some embodiments, "about" includes that the word about limits the number within the range of ± 5-10%. For example, evaporating the solvent at about 80°C includes evaporating the solvent at 79°C, 80°C, or 81°C.

[0068] As used herein, the phrase "lithium-filled garnet electrolyte" refers to an oxide characterized by having a crystal structure related to the garnet crystal structure. Lithium-filled garnet includes compounds having the general formula: Li A La B M' c M” D Zr E O F , Li A La B M' C M” D Ta E O F , or Li A La B M' C M” DNb E O F , where 4 < A < 8.5, 1.5 < B < 4, 0 ≤ C ≤ 2, 0 ≤ D ≤ 2; 0 ≤ E < 2, 10 < F < 13, and M' and M'' are each independently selected from Al, Mo, W, Nb, Sb, Ca, Ba, Sr, Ce, Hf, Rb, or Ta, or Li in each instance a La b Zr c Al d Me” e O f , where 5 < a < 7.7, 2 < b < 4, 0 < c ≤ 2.5, 0 ≤ d < 2, 0 ≤ e < 2, 10 < f < 13, where Me” is a metal selected from Nb, Ta, V, W, Mo, or Sb and as described herein. The garnets used in the present invention also include those garnets described above, which are doped with Al 2 O 3 . The garnets used in the present invention also include those garnets described above, which are doped so that Al 3+ replaces Li + in the garnet. The lithium-filled garnets used in the present invention, and the garnets, generally include, but are not limited to, Li 7.0 La 3 (Zr t1 + Nb t2 + Ta t3 )O 12 + 0.35Al 2 O 3 , where (t1 + t2 + t3 = subscript 2) so that the ratio of La:(Zr / Nb / Ta) is 3:2. Additionally, the garnets used in the present invention include, but are not limited to, Li x La 3 Zr 2 O 12 + yAl 2 O 3 , where x is in the range of 5.5 to 9, and y is in the range of 0 to 1. In some embodiments, x is 7, and y is 1.0. In some embodiments, x is 7, and y is 0.35. In some embodiments, x is 7, and y is 0.7. In some embodiments, x is 7, and y is 0.4. Additionally, the garnets used in the present invention include, but are not limited to, Li x La 3 Zr 2 O 12 + yAl 2 O 3 .

[0069] The garnets used in the present invention do not include YAG-garnet (i.e., yttrium aluminum garnet, or, e.g., Y3 Al 5 O 12 ). As used in the present invention, garnet does not include silicate-based garnets such as pyrope, almandine, spessartine, grossular, hessonite or cinnamonite, tsavorite, grossular and andradite as well as solid solutions pyrope-almandine-sponsartine and grossular-grossular-andradite. Garnet here does not include island silicate stones, which have the general formula X 3 Y 2 (SiO 4 ) 3 , wherein X is Ca, Mg, Fe, and, or Mn; and Y is Al, Fe, and, or Cr.

[0070] The term "porous" as used herein refers to a material comprising pores, such as nanopores, mesopores, or micropores.

[0071] II. Dimensions

[0072] In some embodiments, the present invention provides a series of structures and nanostructures of rechargeable battery positive electrodes. In these embodiments, the positive electrode includes active materials (intercalation chemical cathode materials, conversion chemical cathode materials, or combinations thereof), cathode electrolyte materials (small particle size ceramic, oxide, or sulfide electrolyte materials), ground, milled, and mixed with the active materials, and optionally binders, and electronic conductor additives. In some embodiments, at least the cathode active material and the cathode electrolyte material are milled so that the particle size (diameter) ratio of the large cathode active material particle size to the small cathode electrolyte particle size is at least 3:1 or greater. In some embodiments, the particle size ratio (large particle size: small particle size) is at least 3:1, or at least 3.5:1, or at least 4:1, or at least 4.5:1, or at least 5:1, or at least 5.5:1, or at least 6:1, or at least 6.5:1, or at least 7:1, or at least 7.5:1, or at least 8:1, or at least 8.5:1, or at least 9:1, or at least 9.5:1, or at least 10:1, or at least 10.5:1, or at least 11:1, or at least 11.5:1, or at least 12:1, or at least 12.5:1, or at least 13:1, or at least 13.5:1, or at least 14:1, or at least 14.5:1, or at least 15:1, or at least 15.5:1, or at least 16:1 1, or at least 16.5:1, or at least 17:1, or at least 17.5:1, or at least 18:1, or at least 18.5:1, or at least 19:1, or at least 19.5:1, or at least 20:1, or at least 20.5:1, or at least 21:1, or at least 215:1, or at least 22:1, or at least 22.5:1, or at least 23:1, or at least 23.5:1, or at least 24:1, or at least 24.5:1, or at least 25:1, or at least 25.5:1, or at least 26:1, or at least 26.5:1, or at least 27:1, or at least 27.5:1, or at least 28:1, or at least 28.5:1, or at least 29:1, or at least 29.5:1, or at least 30:1.In some embodiments, the particle size ratio (large particle size: small particle size) is 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, 6:1, 6.5:1, 7:1, 7.5:1, 8:1, 8.5:1, 9:1, 9.5:1, 10:1, 10.5:1, 11:1, 11.5:1, 12:1, 12.5:1, 13:1, 13.5:1, 14:1, 14.5:1, 15:1, 15.5:1, 16:1, : 1, 16.5: 1, 17: 1, 17.5: 1, 18: 1, 18.5: 1, 19: 1, 19.5: 1, 20: 1, 20.5: 1, 21: 1, 215: 1, 22: 1, 22.5: 1, 23: 1, 23.5: 1, 24: 1, 24.5: 1, 25: 1, 25.5: 1, 26: 1, 26.5: 1, 27: 1, 27.5: 1, 28: 1, 28.5: 1, 29: 1, 29.5: 1, or 30: 1. In some embodiments, the cathode active particles are large particles. In some embodiments, the cathode electrolyte particles are small particles.

[0073] In some embodiments, the present invention provides a series of structures and nanostructures of positive electrodes for rechargeable batteries. In these embodiments, the positive electrode comprises an active material, a cathode electrolyte material and the active material, and optionally a binder and an electronic conductor additive are ground and mixed. In some embodiments, at least the cathode active material and the cathode electrolyte material are ground so that the particle size (diameter) ratio of the large cathode active material particle size to the small cathode electrolyte particle size is at least 3:1 or greater. In some embodiments, the active material is NCA, and its D 50 is one of 250-400 nm, 1-2 μm, or 5-6 μm. In some embodiments, the cathode electrolyte has a D 50 It is 250-300nm.

[0074] In some embodiments, the present invention provides a series of rechargeable battery positive electrodes, which include particles having D 50 The active material has a diameter of 1-5 or 5 μm. In these embodiments, the cathode electrolyte contains D 50 In these embodiments, the cathode electrolyte contains D 50 Particles with a diameter of 300 nm.

[0075] III. Materials

[0076] As described in Example 1, when the particle size ratio of the large positive active material particle size to the small cathode electrolyte particle size is about 4:1 or greater, the infiltration can achieve a low volume fraction. In some embodiments described in the present invention, the active material of the positive electrode is selected from an oxide intercalation material, and the oxide intercalation material is selected from LiMPO 4 (M=Fe、NiCo、Mn)、Li x Ti y O z (where x is from 0 to 8, y is from 1 to 12, and z is from 1 to 24), LiMn 2 O 4 、LiMn 2a Ni a O 4 (where a is from 0 to 2), LiCoO 2 、Li(NiCoMn)O 2 、Li(NiCoAl)O 2 , and nickel cobalt aluminum oxide [NCA]. In some other embodiments, the positive electrode active material includes a metal fluoride conversion chemical material, and it is selected from FeF 2 、NiF 2 ,FeO x F 3-2x , FeF 3 , MnF 3 , CoF 3 ,CuF 2 In some other embodiments, the positive electrode active material comprises a composition of an internal insertion oxide and a conversion chemical metal fluoride.

[0077] In certain embodiments, the cathode active material is a nanoscale conversion chemical material (e.g., FeF 3). Suitable cathode active materials are proposed in the following patents: U.S. formal patent application No. 13 / 922,214 filed on June 19, 2013, entitled NANOSTRUCTURED MATERIALS FOR ELECTROCHEMICAL CONVERSION REACTIONS, published on June 19, 2014, and its U.S. patent application publication No. 2014 / 0170493; International PCT patent application No. PCT / US2015 / 017584 filed on February 25, 2015, entitled HYBRID ELECTRODES WITH BOTH INTERCALATION AND CONVERSION MATERIALS; U.S. provisional patent application No. 62 / 096,510 filed on December 23, 2014, entitled LITHIUM RICH NICKEL MANGANESE COBALT OXIDE (LR-NMC). All the contents of the above applications are incorporated herein by reference in their entirety.

[0078] In some embodiments, the positive active material is NCA, wherein the median particle size is about 5-6 μm. In this embodiment, the catholyte needs to maintain a particle size ratio of at least 4:1 or greater, and the catholyte will be a catholyte with a particle size less than 1.5 μm (e.g., 1.2-1.5 μm).

[0079] In some embodiments, the positive active material is NCA, wherein the median particle size is about 5-6 μm. In this embodiment, the catholyte needs to maintain a particle size ratio of at least 4:1 or greater, and the catholyte will be a catholyte with a particle size less than 1.5 μm (e.g., 1.2-1.5 μm).

[0080] In some embodiments, the positive electrode active material is FeF 3 , wherein the median particle size is about 300 nm. In this embodiment, the catholyte needs to maintain a particle size ratio of at least 4:1 or greater, and the catholyte will be a catholyte with a particle size less than 80 nm (e.g., 60-80 nm).

[0081] In some embodiments, the positive electrode active material is NCA, wherein the median particle size (D 50 ) is about 4-10 μm. In this specific example, the electrolyte needs to maintain a particle size ratio of at least 20:1 or greater, and the cathode electrolyte will be a cathode electrolyte having a particle size less than 500nm (e.g., 200nm).

[0082] In some embodiments, the positive electrode active material comprises FeF 3, carbon, and an ion conductor, wherein the diameter of the composite is 1 μm. In this specific embodiment, the cathode electrolyte is required to maintain a particle size ratio of at least 20:1, 4:1, or 1:1, and the cathode electrolyte will be a cathode electrolyte having a particle size of, for example, about 50 nm, 250 nm, or 1 μm.

[0083] In some embodiments, the positive electrode active material comprises FeF 3 , carbon, and an ion conductor, wherein the diameter of the composite is 10 μm. In this specific embodiment, the cathode electrolyte is required to maintain a particle size ratio of at least 20:1, 4:1, or 1:1, and the cathode electrolyte will be a cathode electrolyte having a particle size of, for example, about 500 nm, 2.5 μm, or 10 μm.

[0084] In some embodiments, the positive electrode active material comprises FeF 3 , carbon, and an ion conductor, wherein the diameter of the composite is 100 μm. In this specific embodiment, the cathode electrolyte is required to maintain a particle size ratio of at least 20:1, 4:1, or 1:1, and the cathode electrolyte will be a cathode electrolyte having a particle size of, for example, about 5 μm, 25 μm, or 100 μm.

[0085] IV. Methods

[0086] The present disclosure relates to electrochemical devices and materials thereof. More specifically, embodiments of the present invention describe a low porosity electrode comprising large particles and small particles. The large particles are electrochemically active materials. The small particles are ionically conductive materials, such as sulfide-based or garnet-based catholytes (e.g., lithium-filled garnets). In some embodiments, the large particles and small particles are characterized by a dispersion of no more than 0.5. In addition, there are other embodiments.

[0087] In some embodiments, the present invention provides a method for forming an electrode material, wherein the method includes providing a first plurality of particles and a second plurality of particles, wherein the first plurality of particles is characterized by a first median diameter of less than 10 μm, the second plurality of particles is characterized by an ionic conductivity of at least 5e-4 S / cm, the first median diameter is at least 3 times the second median diameter, and the first plurality of particles and the second plurality of particles are characterized by a dispersity of less than 0.25; mixing the first plurality of particles and the second plurality of particles to form a mixed material; and depositing the mixed material onto an electrode; and compressing the electrode.

[0088] In some embodiments, the method of the present invention comprises a drying step of the mixed material.

[0089] In some embodiments, the method of the present invention includes the step of depositing the mixed material on a substrate.

[0090] In some embodiments, in the method of the present invention, the mixing process is performed before deposition.

[0091] In some embodiments, the method of the present invention comprises the step of drying the mixed material.

[0092] In those embodiments, where the material needs to be ground, a range of grinding techniques may be used for grinding. For example, the grinding technique may be selected from dry milling, planetary milling, cryomilling, jet milling, wet milling, or a combination of milling with beads and / or media milling.

[0093] As described above, solid-state battery devices can be widely used in many applications. For example, solid-state batteries containing solid electrolyte materials have many advantages over traditional batteries using liquid electrolytes, and these advantages may include safety and high temperature operation performance. For the efficient operation of solid-state batteries, the components of the solid-state batteries need to have specific properties, such as high conductivity, high energy density, and high capacity. More specifically, solid-state battery electrodes may require active materials that are mixed with fast lithium ion conductive materials with high power capacity. The electrodes may further require electronic conductive components and adhesives for electrode cohesion and adhesion. The effective filling of these solids is crucial for the preparation of high energy density electrodes. It should be noted that the examples described in the present invention include an architecture and algorithm for providing an effective filling electrode structure, which is beneficial to high energy density electrodes.

[0094] When the components of a solid-state electrode are not filled effectively, empty pores are created, resulting in wasted volume that minimizes energy density. In addition to low porosity, the catholyte-impermeable network that results in low rate performance can cause poor ion conduction. In addition, the catholyte-impermeable network allows few ions to enter the electrochemically active material, resulting in low energy capacity.

[0095] In some embodiments, the method described in the present invention includes the following steps: the first step is to prepare a sulfide electrolyte. The sulfide electrolyte may include any sulfide electrolyte described in the present invention. The second step is to reduce the particle size of the electrolyte by grinding technology, such as wet grinding. The third step is to treat the ground electrolyte by centrifugation and reducing the solvent. In some embodiments, the treatment includes solvent evaporation to ensure that the ground electrolyte is about 50w / w% solid / liquid mixed with the liquid, wherein the liquid refers to the grinding solvent. Depending on the grinding conditions, various particle sizes and distributions of particle sizes can be obtained. Then, the ground electrolyte is mixed with the electrode active material (or a substitute such as Al 2 O 3 ) are mixed, wherein the active material has a known and specified particle size. In some embodiments, in this step, the electrolyte and active material are mixed together with a binder and optional carbon. In the next step, the mixed materials are mixed. In the next step, the mixed mixed material is cast into a membrane using a die casting technique (such as grooving, coating, or scraping). In the next step, the cast membrane is dried, for example, on a hot plate, or in an oven (~40-200C, the temperature setting depends on the solvent used). In some embodiments, the method further includes pressurizing or compressing the dried membrane using a rolling pressing technique.

[0096] V. Electrode Structure with Mixed Particle Sizes

[0097] Figure 1 is a simplified diagram of an electrode material according to an embodiment of the present invention. This diagram is only an example and does not unduly limit the scope of the claims. Those skilled in the art will be able to discern any changes, substitutions and modifications. Figure 1As shown, the electrode material 100 includes large-sized particles 102 and small-sized particles 101. The relative sizes and proportions between the large and small particles are not drawn to scale but are provided merely as an illustration. The large-sized particles are electrochemically active materials. The small-sized particles are ion-conductive materials. For example, the large-sized particles include a conversion chemistry material that has been reported in relevant patents, such as U.S. Utility Patent Application No. 13 / 922,214, filed on June 19, 2013, entitled NANOSTRUCTURED MATERIALS FOR ELECTROCHEMICAL CONVERSION REACTIONS, and published on June 19, 2014, with U.S. Patent Application Publication No. 2014 / 0170493; International PCT Patent Application No. PCT / US2015 / 017584, filed on February 25, 2015, entitled HYBRID ELECTRODES WITH BOTH INTERCALATION AND CONVERSION MATERIALS; U.S. Provisional Patent Application No. 62 / 096,510, filed on December 23, 2014, entitled LITHIUM RICH NICKEL MANGANESE COBALT OXIDE (LR-NMC), and each of the listed patents is incorporated herein by reference in its entirety. For example, the electrochemically active material may include, but is not limited to, iron fluoride materials, copper fluoride materials, nickel fluoride materials, and / or other types of materials. The small-sized particles include a solid-state electrolyte or catholyte material. In some embodiments, the small-sized particles may be an ion-conductive electrolyte material that includes Li a X b P c S d O e , where X = Si, Ge, Al, Sn, and combinations thereof, and 5 ≤ a ≤ 15, 0 ≤ b ≤ 3, 1 ≤ c ≤ 4, 6 ≤ S ≤ 18, 0 < e ≤ 5. For example, ion-conductive electrolyte materials have been described in relevant patents: International PCT Patent Application No. PCT / US14 / 38283, filed on May 15, 2014, entitled SOLID STATE CATHOLYTE OR ELECTROLYTE FOR BATTERY USING Li A MP B S C(M = Si, Ge, and / or Sn); similarly, U.S. Patent No. 8,697,292 to Kanno et al. The entire contents of both patents are incorporated herein by reference in their entirety for all purposes. In various embodiments, the relative median particle size of the large particles (electrochemically active material) is at least 3 times larger than the relative median particle size of the small particles (ion conductive material). For example, the median diameter of the large particles is between 1 μm and 10 μm, or between about 0.1 μm and 1 μm, and the median diameter of the small particles is between about 200 nm and 2 μm, or between about 50 nm-200 nm.

[0098] The present invention uses D 50 is a measure of the volume average median particle size.

[0099] In conventional batteries, the electrochemically active material is composed of particles of a size that can be charged and discharged in large quantities at a given current and in a given time. The interstices of the conventional active material are soaked in a liquid electrolyte that provides highly conductive lithium ions to the surface of the active material. In solid-state batteries, the liquid must be replaced by a solid cathode electrolyte material having a high ionic conductivity comparable to that of the liquid cathode electrolyte material. The electrodes herein are designed to allow the cathode electrolyte to permeate through the electrodes and conduct with the lithium ions in the cathode while occupying a minimum volume. The cathode electrolyte does not contribute to the energy density, so any change in the volume of the cathode electrolyte in the absence of any cathode electrolyte will not result in a reduction in the energy density.

[0100] The electrochemical cell of the present invention reduces the porosity to a minimum, either by selecting a particle size ratio or by a compression method, and the porosity does not affect energy storage. In the electrochemical cell of the present invention, the volume occupied by large particles should be as large as possible while maintaining high ionic conductivity through the small particles. In the electrochemical cell of the present invention, the volume occupied by small particles should be as small as possible while maintaining high ionic conductivity through the electrode. In the electrochemical cell of the present invention, the pore volume should be as small as possible. In addition, in the electrochemical cell of the present invention, the share of the small particles participating in the percolation network in the total amount of small particles should be as large as possible. In the electrochemical cell of the present invention, the proportion of large particles in contact with the percolation network of small particles should be as high as possible.

[0101] In the electrochemical electrodes of the embodiments of the present invention, the cathode electrolyte contains small particles, which effectively fill the gaps between large particles in the active material. The small-sized particles fill the spaces and gaps between the large particles and simultaneously provide ion conduction pathways through the electrode. Since the large, electrochemically active particles are the main contributors to the energy capacity, they preferably account for more than 50% of the total volume of the electrode material. The small-sized particles preferably account for no more than 20% of the total volume of the electrode material. It should be noted that the electrode material composed of small-sized particles as fillers can be tightly compacted and have a porosity of no more than 25%.

[0102] It should be noted that the size and distribution of large and small particles in the electrode material affect the performance of the solid-state battery device. For example, the electrode of the present invention can be charged to 80% of the total power capacity within 2 hours. By adjusting the dispersion of the large and small particles, whether in absolute or relative proportions, suitable performance characteristics of the electrode material can be configured. For example: adjusting the dispersion of large and small particles can optimize the ionic conductivity, electronic conductivity, and recharging characteristics of the electrode material. According to various embodiments, the dispersion of large and small particles of the electrode material is less than 0.25. For example, if a set of particles presents a Gaussian distribution The dispersion (σ) of the distribution is the standard deviation of the distribution. In another embodiment, the particle size distribution is approximately log-normal. Wherein, the dispersion degree of the distribution is σ. In each example, the small particles and large particles are uniformly mixed. When the dispersion degree and particle size ratio of large particles to small particles meet the requirements, the fraction of small particles participating in the permeation network (such as ions) can exceed 80%. The fraction of the large particles in contact with the permeation network can exceed 80%. As an example, the dispersion measurement value expressed by the numerical term in the present application refers to the best fit value of the logarithmic normal distribution of the experimental measurement value of the dispersion and particle size distribution. For example, the dispersion value (σ) can be calculated using the above formula. It should be noted that different dispersion values ​​can be used according to the specific example. As described above, large and small particles with dispersion values ​​less than 0.25 are suitable for use in certain applications. In some applications, large and small particles with dispersion values ​​less than 0.5 can be used to form cathode electrolyte materials.

[0103] In addition to the large particles of electrochemically active materials and the small particles of ion conductive materials, the electrode material may further include electronic conductive additive materials and / or binder materials. For example, the electronic conductive additive materials include acetylene black, carbon black, graphene, graphite, activated carbon, C65, C45, VGCF, carbon fiber, carbon nanotubes, Ketjen black, and / or others. The binding material may include rubber, polymer, and / or other materials.

[0104] Figure 2 is a simplified diagram of electrode materials according to the present invention. This diagram is for illustrative purposes only and does not unduly limit the scope of the claims. Any changes, substitutions and modifications can be discerned by those skilled in the art. Figure 2 As shown, the electrochemically active material is larger than the ion-conducting particles, and the ion-conducting particles fill the gaps between the electrochemically active materials. For example, the electrochemically active material includes cathode active particles, and the ion-conducting particles include electrolyte (or cathode electrolyte) particles.

[0105] Figure 3 1 is a simplified diagram of a permeation network according to an embodiment of the present invention. This diagram is only an example and does not unduly limit the scope of the claims. Those skilled in the art will be able to discern any form of changes, substitutions and modifications. Figure 3 In the figure, the electrode material shows only ion-conducting particles, where the large electrochemically active material has been removed from the figure to better illustrate the percolation network of the small particles. The ion-conducting material is suitable as a catholyte material because the conductive material allows substances such as lithium ions to permeate through the electrode during the charge / discharge cycle.

[0106] Figure 4 is the percolation threshold (ρ s *where ρ s is the volume of the small particle (V s ) in the total particle volume, V s / (V s +V l )) and a simplified diagram of the particle size (diameter) ratio between large and small particles of randomly filled electrode materials. This diagram is only an example and does not overly limit the scope of the claims. Those skilled in the art will be able to discern any form of changes, substitutions and modifications. Figure 4 The percolation threshold ρ S *Relationship with the particle size ratio between large and small particles in the electrode. For example, a particle size ratio of 6 in the figure means that the median diameter of the large particles is about 6 times the median diameter of the small particles. Generally, the permeation threshold ρ S *Decreases as the particle size ratio increases. However, when the particle size ratio is larger, permeation can be achieved through many small connections that do not provide effective conductivity. For example, ignoring connections within a radius <1nm, increasing the permeation threshold, the particle size ratio becomes less sensitive to its effect. Figure 4 Figure 3 illustrates the percolation thresholds for the seven sample distributions where the particles are packed without compression. It is clear that ρ S * Varies within a range. When the particle size ratio is 6, ρ S * varies in the range of approximately [0,0.12]. It should be noted that ρ S*<0.12 is lower than expected, while when the particle size ratio is other values, ρ S *Usually above 0.15. For example, Figure 4 It shows that ρ S *Decreases with increasing particle size ratio and increases with increasing dispersion.

[0107] Figure 5 1 is a simplified diagram of the ratio of the size of the large and small particles in the compressed filling material shown in the embodiment herein. This diagram is only for example and does not unduly limit the scope of the claims. Any changes, substitutions and modifications can be discerned by those skilled in the art. Figure 5 As shown, compression of the particles leads to a change in the percolation threshold. More specifically, when a small compression of 2% is achieved, the percolation thresholds of the seven distributions further decrease, which shows the necessity of compression.

[0108] Figure 6 is a simplified diagram of the relationship between random packing density and particle size ratio shown in the embodiments herein. This diagram is for illustrative purposes only and does not unduly limit the scope of the claims. Any changes, substitutions and modifications can be discerned by those skilled in the art. Figure 6 As shown in rcp = total volume of particles / total volume of container. For example, φ rcp =1, which means that the volume of the container is completely filled. If the particle size ratio is 1, it means that the maximum filling of the randomly filled spheres is φ rcp ≈0.64. Figure 6 represents the random filling fraction of the permeation system. It can be seen that φ rcp It increases with the increase of particle size ratio and decreases with the increase of dispersion. When the particle size ratio is greater than 1, it can be obtained that φ rcp >0.64, which indicates the beneficial aspect of the particle size difference between the catholyte and the active particles in the electrode. As mentioned above, a high packing density of the electrode material is desirable.

[0109] Figure 7 The total fraction of the volume of the container occupied by small particles of different particle size ratios after percolation threshold renormalization is briefly described. This figure is only an example and does not overly limit the scope of the claims. Those skilled in the art will be able to discern any form of changes, substitutions and modifications. More specifically, Figure 7 The product φ on the vertical axis rcp ρ S * Values ​​given for small particles φ S The total fraction of the container volume occupied at the percolation threshold. Figure 7 As shown, 2% compression (volume) can be used for filling, R CThe connections <1 nm are negligible. The compression mentioned in this paper refers to a 2% reduction in the size of the simulation box, resulting in an overlap of about 2% between particles. This is the particle shrinkage (necking) model. The figure shows that at the percolation critical value, φ S It is almost unchanged with the change of particle size ratio and dispersion. As can be seen from the figure, if the small particles occupy >14% of the total container volume, the dispersion is low enough, and the particle size ratio is high enough, penetration will occur.

[0110] In some embodiments, compression is applied to the electrode. Compression can use a calender, the roller diameter of the calender is greater than 90 mm, 100 mm, 110 mm, or 120 mm, and the pipeline pressure is greater than 8 MPa, 9 MPa, 10 MPa, 11 MPa, the electrode belt width is less than 300 mm, and the belt feed speed is less than 5 cm / s.

[0111] Figure 8 The functional relationship between the volume of the small particles described herein and the area fraction of the 2D cross-section occupied by the small particles is shown. This figure is only for example and does not unduly limit the scope of the claims. Those skilled in the art will be able to discern any form of changes, substitutions and modifications. Figure 8 As shown, the cross-sectional area φ 2D is the volume occupied by small particles in the 7 samples ρ S The vertical axis of the function. Figure 8 The cross-sectional area covered by the penetrating particles is related to ρ S The linear relationships of all distributions are almost the same except for the particle size ratio of 2 and the truncated distribution.

[0112] In this figure, δ is the dispersion degree, η is the median particle size ratio (d l / d s ).

[0113] Fig. 9 The normal 2D cross-sectional area fraction is shown as a function of the 2% compression electrode permeation threshold described in the embodiment of the present invention. This figure is only for example and does not unduly limit the scope of the claims. Those skilled in the art will be able to discern any form of changes, substitutions and modifications. The variable φ S It refers to the fraction of the 2D cross-section of the 3D container volume occupied by all small particles. 2D It refers to the fraction of the 2D cross-section of the 3D container volume occupied by small particles that partially penetrate the network. Fig. 9 Indicates that S The normalized cross-sectional area fraction is taken as the small particle volume ρ S When all small particles form the percolation cluster, the φ 2D / φ SThe ratio is 1. As shown in the figure, except for the particle size ratio of 2 and the truncated distribution, almost all small particles contribute to the permeation cluster, ρ S >0.20. The results show that ρ S >0.20, assuming φ 2D ≈φ S Provide a sufficiently close situation.

[0114] Fig.10 The relationship between the fraction of large particles in contact with penetrating particles as a function of the fraction of small particles described in the embodiments of the present invention is described. This figure is for example only and does not unduly limit the scope of the claims. Those skilled in the art will be able to discern any form of changes, substitutions and modifications. In these examples, the material in the graph is compressed at 2% volume. More specifically, the graph shows the fraction of large particles in contact with small penetrating particles as a function of 7 distributions p S These data show that when the percolation threshold (ρ S ~10-15%), almost all large particles are in contact with small penetrating particles.

[0115] Fig.11 SEM images of electrode materials with large and small particles that have not been tightly compressed. Fig.11 It can be seen that the large particles and the small particles are uniformly mixed, wherein the large particles are in direct contact with the small particles. Fig.11 In the embodiment of the present invention, the large particles have a median diameter of about 5 μm, and the small particles have a median diameter of about 300 nm.

[0116] Fig.12 This is a SEM image of the electrode material with different particle sizes after compression. Fig.12 It can be seen that the small particles tightly fill the voids between the large particles. It can be seen that the large particles have a median diameter of about 5 μm, and the small particles have a median diameter of about 300 nm. The porosity of the electrode was measured to be less than 20%, which is consistent with the expected value. In some examples, the compression process includes using a uniaxial compressor or a calender.

[0117] Fig.13 It is described Fig.11 The electrode material represented in . Fig.13 Among them, the largest average particle size particles are the cathode active material particles. The second largest average particle size particles are the cathode electrolyte particles. Finally, the smallest average particle size particles are the electronic conductive additive.

[0118] The above is a complete description of a specific embodiment, and various modifications, substitutions, and equivalents are also applicable. Therefore, the above description and illustration should not be taken as limiting the scope of the present invention, which is defined by the scope of the appended claims.

[0119] VI. Chemical Electrodes

[0120] In some examples, the present invention relates to a solid-state electrode of an electrochemical device, comprising a first plurality of particles of an electrochemically active material, the first particles having a first particle size distribution characterized by a first dispersity of 0.25 or less and a first median diameter. In some embodiments, the first median diameter is from about 10 nm to about 10 μm. In certain embodiments, the first median diameter is about 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 65, 70, 75, 80, 85, 90, 95, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, or 500 nm. In some embodiments, the first median diameter is about 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, or 10 μm. In some embodiments, the electrode comprises a second plurality of particles of an ion-conductive material, the second particles having a second particle size distribution characterized by a second dispersity of 0.25 or less and a second median diameter, the second median diameter being 1 / 3 or less of the first median diameter.

[0121] In some embodiments, the electrode has a volume fraction of the second particles that is less than 20% of the total particle volume of the electrode.

[0122] In some embodiments, the electrode is characterized by a porosity of less than 20 volume percent. In certain embodiments, the porosity is less than 15% v / v. In certain embodiments, the porosity is less than 10% v / v.

[0123] In some embodiments, the ion-conductive material in the electrode comprises Li a X b P c S d O e , where X = Si, Ge, Al, Sn, and combinations thereof, and 5 ≤ a ≤ 15, 0 < b ≤ 3, 1 ≤ c ≤ 4, 6 ≤ S ≤ 18, 0 < e ≤ 5. In some embodiments, X is Si. In other embodiments, X is Si and Sn. In other embodiments, X is Sn. In still other embodiments, X is Ge. In some embodiments, X is Si and Ge.

[0124] In some embodiments, the electrode of the present invention can be charged to 80% or more of the electrode capacitance within 2 hours.

[0125] In some embodiments, the electrode described in the present invention further comprises an electronic conductive additive selected from acetylene black, graphene, graphite, carbon black, activated carbon, C65, C45, VGCF, carbon fiber, carbon nanotubes, Ketjen black, or a combination thereof.

[0126] In some embodiments, the electrode described herein further comprises a binder material, wherein the binder material comprises rubber and / or a polymer.

[0127] In some embodiments, the electrode of the present invention further comprises a percolation network composed of a portion of second particles, and the proportion of the second particles participating in the percolation network is greater than 80%. In some embodiments, 80% of the second particles are incorporated into the percolation network. In some embodiments, 85% of the second particles are incorporated into the percolation network. In some embodiments, 90% of the second particles are incorporated into the percolation network. In some embodiments, 95% of the second particles are incorporated into the percolation network. In some embodiments, 100% of the second particles are incorporated into the percolation network. In some embodiments, the electrode of the present invention further comprises a percolation network, and the proportion of the first plurality of particles that contact the percolation network is greater than 80%.

[0128] In some embodiments, the solid-state electrochemical electrode described in the present invention includes an active material characterized by a first particle size distribution having a first median particle size; and a cathode electrolyte material characterized by a second particle size distribution having a second median particle size; wherein the volume ratio of the active material to the cathode electrolyte material is from 99:1 to 1:1; and wherein the particle size ratio of the first median particle size to the second median particle size is at least 3:1 or greater.

[0129] In some embodiments, the solid-state electrochemical electrode described herein, wherein the first particle size distribution has a dispersity of 0.25 or less.

[0130] In some embodiments, the present invention is a solid-state electrochemical electrode wherein the second particle size distribution has a dispersity of 0.25 or less.

[0131] In some embodiments, the solid-state chemical electrode of the present invention has a porosity of less than 20% by volume.

[0132] In some embodiments, the solid-state electrochemical electrode of the present invention further comprises an electronic conductive additive, wherein the electronic conductive additive comprises acetylene black, carbon black, activated carbon, C65, C45, VGCF, carbon fiber, carbon nanotube, and / or Ketjen black. In some embodiments, the electrochemical cell further comprises a binder material, wherein the binder material is selected from rubber or polymer.

[0133] In some embodiments, the solid-state electrochemical electrode described herein, wherein the cathode electrolyte particles form a percolating network.

[0134] In some embodiments, the present invention is a solid-state electrochemical electrode wherein greater than 80% of the catholyte particles in the electrode are bound within the percolating network. Example

[0135] In the embodiments described herein, unless otherwise specified, the subscript values ​​of the solid electrolyte of the present invention represent the molar ratio of the elements of the chemical precursors used to form the required components. If detected by analytical methods, the actual molar ratio of the elements of the electrolyte will be different, and different detection methods will also be different, such as: X-ray fluorescence spectroscopy or inductively coupled plasma spectroscopy.

[0136] Example 1: Filling ratio

[0137] In this example, a series of filling schemes were investigated, and the filling density and permeation conductivity were tested. Fig.14 As shown in Figure 1, one filling scheme includes two particle sizes in the electrode. Fig.14 As shown on the left, the large-size particles (1401, cathode active material) are monodisperse, while the small-size particles are Gaussian-distributed (1402, cathode electrolyte ion conductor). Fig.14 As shown on the right, another solution is considered to be that the large particle size particles and the small particle size particles are Gaussian in particle size distribution. In each case of this embodiment, the diameter ratio of the large particle size particles to the small particle size particles is constant at 4.

[0138] In this embodiment, in the second aspect, other filling schemes were investigated, and the filling density and permeation conductivity were tested. Fig.15 As shown, the packing scheme includes two particle sizes in the electrode. Fig.15 As shown, the large-size particles (1501, cathode active material) and the small-size particles (1502, cathode electrolyte ion conductor) are both a collection of monodisperse particle sizes. Fig.15 As shown on the left, one approach includes fixing the particle size (diameter) ratio of the large particle size to the small particle size at 4. Fig.15As shown on the right, another embodiment includes fixing the particle size (diameter) ratio of the large particle size particles to the small particle size particles at 2.

[0139] Example 2: Function of conductivity versus particle size ratio

[0140] In this embodiment, Al 2 O 3 and LSTPS need to be ground to 5-6 μm and 200-250 nm respectively. These particle sizes give a large particle size to small particle size ratio of about 20:1. In a single batch, Al 2 O 3 and LSTPS were ground to 1.25-1.5 μm and 200-250 nm, respectively. These particle sizes gave a ratio of large to small particle size of about 5:1. In a third separate batch, Al 2 O 3 and LSTPS need to be milled to the same particle size of 200-250 nm. These particle sizes give a ratio of large particle size to small particle size of about 1:1. In this example, ionic conductivity can be measured. Al 2 O 3 It can be used as a substitute for cathode active materials.

[0141] Typically, the electrode composition is prepared by providing a suspension consisting of Al 2 O 3 The suspension is cast and allowed to dry on a substrate (e.g., aluminum or stainless steel). A uniaxial compressor with a pressure of about 200 to 300 Pa is used to compress the dried composite material. In this embodiment, the LSTPS particle size is set to a D50 of 250-300 nm, and the Al 2 O 3 The particle size varies with the above-mentioned particle size ratio.

[0142] Each sample was placed in contact with a lithium-containing electrode and the conductivity of the electrode formulation was tested. Fig.16 shown.

[0143] like Fig.16 As shown, higher ionic conductivities can be measured for electrode compositions with a large-particle-to-small-particle ratio of 20:1 and 5:1 compared to an electrode composition with a large-particle-to-small-particle ratio of 1:1. Electrode compositions with a large-particle-to-small-particle ratio of 1:1 have conductivity that is almost 2 orders of magnitude lower than electrode compositions with a large-particle-to-small-particle ratio of at least 5:1 or higher. In this embodiment, it was observed that the σi (ionic conductivity) of electrode compositions with a large-particle-to-small-particle ratio of 5:1 or higher was about 5-7e-6 S / cm. From Fig.16Data trends suggest that the highest permeability conductivity is determined when the particle size ratio of large particles to small particles is 4:1 or higher.

[0144] like Fig.17 As shown, the Al 2 O 3 The particles (1702) have an approximate particle diameter of 4-6 μm, and the LSTPS particles (1701) have an approximate particle diameter of about 250 nm. Fig.18 As shown, the Al 2 O 3 The particles (1802) and the LSTPS particles (1801) are uniformly mixed. It can be observed that the LSTPS particles (1801) are much more than the Al 2 O 3 The LSTPS particles (1801) are neck-shaped, or share or contact the surface of the particles (1802). In this way, it can be observed that the LSTPS particles (1801) form a percolation network in the electrode formulation, through which the Li + Can conduct electricity.

[0145] like Fig.19 As shown, the Al 2 O 3 The particles (1902) have an approximate particle diameter of about 0.75-4 μm, and the LSTPS particles (1901) have an approximate particle diameter of about 250 nm. Fig. 20 As shown, the Al 2 O 3 The particles (2002) and the LSTPS particles (2001) are uniformly mixed. It can be observed that the LSTPS particles (2001) shrink together to form a percolating network.

[0146] like Fig.21 As shown, the Al 2 O 3 The particle (2102) has an approximate particle diameter of about 250 nm, and the LSTPS particle (2101) has an approximate particle diameter of about 250 nm. Fig. 22 As shown, the Al 2 O 3 The particles (2202) and the LSTPS particles (2201) are uniformly mixed. It can be observed that the LSTPS particles (2201) shrink together, but only in a smaller range of about 5-20 μm. 2 O 3 The particles (2202) and the LSTPS particles (2001) are not allowed to form Fig.18 The same extensive percolation network shown in .

[0147] like Fig. 27 As shown, the relevant experiments verify the change of conductivity as a function of the volume amount of catholyte in the electrode. In order to achieve high energy density in an electrochemical cell, the majority of the positive electrode should be active material, and a small portion of the positive electrode should be catholyte material (a small amount of catholyte). Fig. 27 It is shown that at lower cathode electrolyte volume fractions, the difference in conductivity of an electrode having a large particle size to small particle size ratio of 1:1 is 2 orders of magnitude smaller than that of an electrode having a large particle size to small particle size ratio of at least 5:1 or more.

[0148] Example 3: Increase the amount of large particles

[0149] As described above, when the large:small particle size ratio is at least 4:1 or greater, the smaller size particles of the sulfide catholyte tend to form a percolating network. Therefore, in this example, the large particles representing the cathode active material are intended to maximize the amount of cathode active material in the electrode formulation, while still maintaining sufficient catholyte particles to ensure high conductivity. Fig.23 and Fig.24 Display Al 2 O 3 The electrode composition is composed of particles (2302 and 2402) and LSTPS particles (2301 and 2401), wherein the Al 2 O 3 The particle size ratio of LSTPS is 20:1. Fig.23 and 24 As shown, the Al 2 O 3 The particles (2302 and 2402) and the LSTPS particles (2301 and 2201) are uniformly mixed. The LSTPS particles (2301 and 2401) are observed to shrink together. Fig.23 In, Al 2 O 3 The volume ratio of LSTPS particles is 80:20. Fig.24 In, Al 2 O 3 The volume ratio of LSTPS particles is 44:54. 2 O 3 :LSTPS particle volume may improve mixing performance.

[0150] Example 4: Grinding electrode particles

[0151] In this embodiment, Al 2 O 3 and LSTPS to a range of particle sizes to facilitate the preparation of specific Al 2 O3 In the example, the ground particles are as follows: Fig.25 shown.

[0152] like Fig.25 As shown, in this embodiment, the Al 2 O 3 :LSTPS particles can be ground into the following particle sizes:

[0153] Particle size (diameter, μm) <![CDATA[D 10 ]]> <![CDATA[D 50 ]]> <![CDATA[D 90 ]]> LSTP 0.17 0.4 1.7 <![CDATA[Al 2 THE 3 ]]> 2.6 4.0 5.6

[0154] Example 5: Grinding electrode particles

[0155] In this example, nickel cobalt aluminum oxide (NCA) and LSTPS were ground into a range of particle sizes to facilitate the preparation of electrode formulations containing specific NCA:LSTPS particle size ratios. Fig.26 shown.

[0156] like Fig.26 As shown, in this embodiment, the NCA:LSTPS particles can be ground into the following particle sizes:

[0157] Particle size (diameter, μm) <![CDATA[D 10 ]]> <![CDATA[D 50 ]]> <![CDATA[D 90 ]]> LSTP 0.15 0.34 0.71 NCA 5.91 8.6 12.7

[0158] In addition, another technical solution provided by the present invention is: a solid-state electrode for an electrochemical device, comprising: a first plurality of particles of an electrochemically active material, the first plurality of particles having a first particle size distribution characterized by a first dispersion of 0.25 or less and a first median diameter; and a second plurality of particles of an ion conductive material, the second plurality of particles having a second particle size distribution characterized by a second dispersion of 0.25 or less and a second median diameter, the second median diameter being 1 / 3 or less of the first median diameter; wherein the total ionic conductivity of the electrode is greater than 1% of the conductivity of the bulk ion conductive material.

[0159] Although the foregoing examples have been described in some detail to facilitate clear understanding, it is clear that some changes and modifications will fall within the scope of the appended claims. It should be noted that there are many ways to improve the processes, systems and devices based on the embodiments listed in this specification. Accordingly, this embodiment should be considered illustrative rather than restrictive, and the embodiments of the present invention are not limited to the details given in the present invention.

Claims

1. Solid-state electrodes for electrochemical devices, comprising: a first plurality of particles of an electrochemically active material, the first plurality of particles having a first particle size distribution characterized by a first dispersity of 0.25 or less and a first median diameter; and a second plurality of particles of an ionically conductive material, the second plurality of particles having a second particle size distribution characterized by a second dispersity of 0.25 or less and a second median diameter, a particle size ratio between the first median diameter and the second median diameter being at least 10:1; wherein the median diameter is the volume average median particle diameter determined by SEM; wherein the electrode is characterized by a porosity of less than 10% by volume as determined by SEM; The electrochemically active material is selected from: LiMPO4, wherein M is Fe, Ni, Co or Mn; Li x Ti y O z , where x is from 0 to 8, y is from 1 to 12, and z is from 1 to 24; LiMn2O4; LiMn 2a Ni a O4, wherein a is from 0 to 2; LiCoO2; Li(NiCoMn)O2; the group consisting of Li(NiCoAl)O2 and nickel cobalt aluminum oxide [NCA]; and wherein the ion conductive material comprises Li a X b P c S d O e , where X = Si, Ge, Al, Sn and combinations thereof, and where 5 ≤ a ≤ 15, 0 < b ≤ 3, 1 ≤ c ≤ 4, 6 ≤ d ≤ 18 and 0 < e ≤ 5. 2 . The electrode according to claim 1 , wherein the electrode comprises a volume fraction of second particles less than 20% relative to the total particle volume of the electrode.

3. The electrode according to claim 1 further comprises an electronically conductive additive, wherein the electronically conductive additive comprises acetylene black, carbon black, activated carbon, C65, C45, VGCF, carbon fiber, carbon nanotubes, Ketjen black or a combination thereof; and / or further comprises a binding material, wherein the binding material is a polymer.

4. The electrode of claim 1, further comprising a percolating network of ionically conductive material.

5. A solid-state battery comprising the solid-state electrode according to claim 1, a solid-state electrolyte and a lithium metal anode.

6. Solid-state electrochemical electrodes, including: an active material characterized by a first particle size distribution having a first median particle size; a catholyte material characterized by a second particle size distribution having a second median particle size; wherein the volume ratio of active material to cathode electrolyte material is from 99:1 to 1:1; wherein the particle size ratio between the first median particle size and the second median particle size is at least 10:1; wherein the median diameter is the volume average median particle diameter determined by SEM; wherein the electrode is characterized by a porosity of less than 10% by volume as determined by SEM; The electrochemically active material is selected from: LiMPO4, wherein M is Fe, Ni, Co or Mn; Li x Ti y O z , where x is from 0 to 8, y is from 1 to 12, and z is from 1 to 24; LiMn2O4; LiMn 2a Ni a O4, where a is from 0 to 2; LiCoO2; Li(NiCoMn)O2; The group consisting of Li(NiCoAl)O2 and nickel cobalt aluminum oxide [NCA]; and The cathode electrolyte material includes Li a MP b S c O d , wherein M is Si, Ge, Sn, and / or Al, and wherein 2≤a≤8, 0.5≤b≤2.5, 4≤c≤12, and d<3. 7 . The electrode according to claim 6 , wherein the first particle size distribution has a dispersity of 0.25 or less, and / or wherein the second particle size distribution has a dispersity of 0.25 or less.

8. The electrode according to claim 6, further comprising an electronically conductive additive, wherein the electronically conductive additive comprises acetylene black, carbon black, activated carbon, C65, C45, VGCF, carbon fiber, carbon nanotubes, Ketjen black or a combination thereof; and / or further comprising a binding material, wherein the binding material is a polymer.

9. The electrode of claim 6, wherein the catholyte material forms a percolating network.

10. Electrochemical cells, including Anode current collector; an anode in direct contact with the anode current collector; An electrolyte in direct contact with the anode, the anode being located between the anode current collector and the electrolyte, and the electrolyte being characterized by at least 1e -4 Ionic conductivity in S / cm; and A solid positive electrode in direct contact with the electrolyte, wherein the solid positive electrode is the solid electrochemical electrode according to claim 6.

11. The battery of claim 10, wherein the first particle size distribution of the solid positive electrode has a dispersity of 0.25 or less; and / or wherein the second particle size distribution of the solid positive electrode has a dispersity of 0.25 or less.

12. The battery of claim 10, wherein the catholyte material of the solid state positive electrode forms a percolating network.

13. The electrode of claim 3, wherein the polymer is rubber.

14. The electrode of claim 8, wherein the polymer is rubber.

Images