Electrode binder for batteries

Abstract

Electrode binders for use in rechargeable batteries are disclosed. In an embodiment, the electrode binder comprises a styrenic block copolymer (SBC) in an amount of at least 20 wt% for use with electrode active materials such as Si, Si alloys, Si compounds, Si composites, carbon black or graphite. The SBC may be unsaturated (USBC) or hydrogenated (HSBC) or functionalized, the functional groups including maleination, epoxidation, silanization, carboxylic acid / salt, quaternary ammonium salt, sulfonation, etc. In an embodiment, the electrode binder is selected from isoprene rubber (IR), silicone-containing block copolymers, and electronically conductive block copolymers containing blocks that are non-hydrogenated CHD (cyclohexadiene) blocks.

Description

[Technical Field]

[0001] Related applications This application claims the benefit of U.S. Provisional Application No. 63 / 140,892 filed on 24 January 2021, and this entire disclosure is incorporated herein by reference.

[0002] This disclosure relates to a binder for use in electrodes and / or electrolytes within a rechargeable battery. [Background technology]

[0003] Rechargeable batteries, such as lithium ("Li")-ion batteries, have become an integral part of modern life and are widely used in applications including, but not limited to, mobile phones, computers, tablets, power tools, transportation, and energy storage. Ions move from negative to positive through the electrolyte during discharge and in the reverse direction during recharging. A rechargeable battery has several main components: a cathode (positive electrode), an anode (negative electrode), a separator, and an electrolyte mixture as a conductor. Electrochemical reactions that generate voltage and current are facilitated at the coated electrodes, where reduction and oxidation reactions occur. High-capacity (negative) electrodes for batteries with recharge cycle capability and energy density are required for plug-in electric vehicles with extended driving range between charges.

[0004] In the fabrication of battery electrodes, binders are crucial for mechanical stabilization and electrical conductivity. In a typical electrode manufacturing process, electrode active materials such as Si or Si-based materials, fillers, and binders are blended to form a paste, which is then coated onto a current collector, either aluminum foil or copper foil. Subsequent drying, calendering, and slitting produce an electrode winding stock, which is then used to construct the battery. The primary function of the electrode binder is to hold the electrode particles and fillers together throughout both the battery manufacturing process and the actual use of the battery, particularly through numerous charge / discharge cycles. For some high-capacity electrodes, such as Si, Si alloys, Si compounds, or Si composite anodes, the expansion / contraction of electrode volume during charge / discharge cycles can be as large as 300% or more, requiring a binder material that can withstand the large expansion / contraction of electrode volume during charge / discharge cycles.

[0005] Rechargeable batteries contain a binder material in a solid electrolyte, which can be a liquid, gel, solid, or film. Liquid electrolytes generally require packaging in a rigid hermetic seal metal "can," which can reduce energy density. Conventional gel polymer electrolytes generally cannot operate over a wide temperature range because the gel freezes at low temperatures and reacts with other battery components, or melts at high temperatures. [Overview of the project] [Problems that the invention aims to solve]

[0006] Improved binder materials for use in rechargeable batteries, electrodes, and / or electrolytes are still needed. [Means for solving the problem]

[0007] In embodiments, the present disclosure relates to binder compositions for use in rechargeable batteries. The binder composition comprises, essentially or consists of, at least 20% by weight of styrene-based block copolymers (SBCs) having a linear, radial, or branched structure; 70% by weight or less of tackifiers selected from hydrocarbon resins, alkyd resins, rosin resins, rosin esters and combinations thereof; and 40% by weight or less of plasticizers selected from vegetable oils, mineral oils, process oils, phthalates and mixtures thereof. The SBC comprises, essentially or consists of, at least one of a) a monovinyl aromatic compound polymer block, b) cyclic conjugated diene polymer block and conjugated diene polymer block, and c) optionally coupling agent residues. The SBC has a residual unsaturation of 0.5 to 25 meq / g.

[0008] In the embodiments, the SBC is either undehydrogenated or selectively, completely, or partially hydrogenated.

[0009] In the embodiment, SBC is functionalized with a functional group selected from the group consisting of maleation, epoxidation, silanation, carboxylic acid / salt, quaternary ammonium salt, and sulfonation.

[0010] In embodiments, an electrode composition is disclosed. The electrode composition comprises, essentially, or consists of, an electrode active material, a filler, and a binder as disclosed herein. The electrode active material is selected from Si, Si alloys, Si compounds, Si composites, carbon black, and graphite, and accounts for at least 85% by weight. The binder is a trace component and accounts for less than 15% by weight.

[0011] In embodiments, electrode compositions are disclosed. The electrode composition comprises electrode active material(s), filler(s), and isoprene rubber (IR) as an electrode binder, wherein the electrode active material(s), such as Si, Si alloy, Si compound, Si composite, carbon black, or graphite, accounts for more than 85% by weight, more than 90% by weight, or more than 94% by weight, and the IR rubber is a trace component, accounting for less than 15% by weight, less than 10% by weight, or less than 6% by weight. In embodiments, the IR rubber is used in latex form, with a particle size of less than 5 microns or less than 2 microns, more preferably less than 1 micron. In embodiments, the IR rubber is crosslinked, and the crosslinking may be introduced during or after the binder manufacturing process, or during or after the battery manufacturing process.

[0012] In embodiments, an electrode composition is disclosed. The electrode composition comprises an electrode active material(s), a filler(s), and a silicone-containing block copolymer as an electrode binder, wherein the electrode active material(s), such as Si, Si alloy, Si compound, Si composite, carbon black, or graphite, accounts for more than 85% by weight, more than 90% by weight, or more than 94% by weight, and the silicone-containing block copolymer is a trace component, accounting for less than 15% by weight, less than 10% by weight, or less than 6% by weight. In embodiments, the silicone-containing block copolymer has at least two blocks and may be a linear polymer, a radial polymer, or a star-shaped polymer, and the silicone-containing block copolymer has a breaking elongation of more than 400% (according to ASTM D412), or a breaking elongation of more than 600% (according to ASTM D412), and / or a breaking elongation of more than 800% (according to ASTM D412). In the embodiment, the silicone-containing block copolymer is crosslinked, and the crosslinking may be introduced during or after the binder manufacturing process, or during or after the battery manufacturing process.

[0013] In embodiments, an electrode composition is disclosed. The electrode composition comprises an electrode active material(s), a filler(s), and an electronically conductive block copolymer as an electrode binder, wherein the electrode active material(s), such as Si, Si alloy, Si compound, Si composite, carbon black, or graphite, accounts for more than 85% by weight, more than 90% by weight, or more than 94% by weight, and the electronically conductive block copolymer is a trace component, accounting for less than 15% by weight, less than 10% by weight, or less than 6% by weight. In embodiments, the electronically conductive block copolymer contains a block that is a dehydrogenated CHD (cyclohexadiene) block, i.e., a polyphenylene block, and the polyphenylene-containing block copolymer has at least two blocks, which may be linear, radial, or star-shaped polymers, and the electronically conductive block copolymer has a break elongation of over 400% (according to ASTM D412), or a break elongation of over 600% (according to ASTM D412), and / or a break elongation of over 800% (according to ASTM D412). In embodiments, the non-hydrogenation level of the CHD (cyclohexadiene) block is at least 50%, preferably at least 70%, and more preferably at least 90%.

[0014] In embodiments, an electrode composition is disclosed. The electrode composition comprises an electrode active material(s), a filler(s), and an ion-conducting block copolymer as an electrode binder, wherein the electrode active material, such as Si, Si alloy, Si compound, Si composite, carbon black, or graphite, accounts for more than 85% by weight, more than 90% by weight, or more than 94% by weight, and the ion-conducting block copolymer is a trace component, accounting for less than 15% by weight, less than 10% by weight, or less than 6% by weight. In embodiments, the ion-conducting block copolymer has an elongation at break of more than 400% (according to ASTM D412), or an elongation at break of more than 600% (according to ASTM D412), and / or an elongation at break of more than 800% (according to ASTM D412).

[0015] In an embodiment, an electrode composition is disclosed. The electrode composition includes an electrode active material(s), a filler, and an electrode binder. The weight percentage of an electrode material such as Si, Si alloy, Si compound, Si composite, carbon black, or graphite is more than 85 wt%, or more than 90 wt%, or more than 94 wt%. The weight percentage of the electrode binder is a minor component, occupying less than 15 wt%, or less than 10 wt%, or less than 6 wt%. The binder is a block copolymer and wraps around the electrode active material. In an embodiment, the electrode “wrapper” block copolymer has an elongation at break (ASTM D412) of more than 400%, or more than 600%, and / or more than 800%. The “wrapper” block copolymer can be selected from USBC, HSBC, functionalized SBC, SBC blend, IR latex, silicone-containing block copolymer, conductive block copolymer, etc.

[0016] In an embodiment, an electrode composition is disclosed. The electrode composition includes an electrode active material, a filler(s), and an electrode binder. The electrode active materials such as Si, Si alloy, Si compound, Si composite, carbon black, or graphite occupy more than 85 wt%, or more than 90 wt%, or more than 94 wt%. The electrode binder is a minor component, occupying less than 15 wt%, or less than 10 wt%, or less than 6 wt%. The active electrode material(s) and the binder(s) form a pie hollow fiber structure, or a tip trilobal fiber structure, or a sheath-core fiber structure, or form islands in a sea fiber structure. In an embodiment, the binder can be any of the block copolymers described above. In an embodiment, the method of making the electrode composition is by fiber spinning, and the fiber spinning can be melt spinning or solution spinning.

[0017] In an embodiment, a dry method for fabricating an electrode winding stock without the use of water or a solvent (s) is disclosed. The electrode includes an electrode active material (s), a filler, and an electrode binder according to any one of claims 1 to 5, and the weight % of an electrode material such as Si, Si alloy, Si compound, Si composite, carbon black or graphite is more than 85 wt%, and the weight % of the electrode binder is a minor component, occupying less than 15 wt%, or less than 10 wt%, or less than 6 wt%. In some embodiments, the dry method is extrusion or fiber spinning.

[0018] Description The following terms are used throughout the specification and, unless otherwise indicated, have the following meanings.

[0019] "At least one of [a group such as A, B, and C]" or "any of [a group such as A, B, and C]" means a single member from this group, two or more members from this group, or a combination of members from this group. For example, at least one of A, B, and C includes, for example, only A, only B, or only C, as well as A and B, A and C, B and C, or A, B, and C, or all other combinations of A, B, and C.

[0020] A list of embodiments presented as "A, B, or C" should be interpreted to include embodiments of only A, only B, only C, "A or B", "A or C", "B or C", or "A, B, or C".

[0021] "Conjugated diene" refers to an organic compound containing a conjugated carbon-carbon double bond and a total of 4 to 12 carbon atoms, for example, 4 to 8 carbon atoms. This organic compound may be any of the substituted butadienes, including but not limited to 1,3-butadiene, 1,3-cyclohexadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1-phenyl-1,3-butadiene, 1,3-pentadiene, 3-butyl-1,3-octadiene, chloroprene, and piperine, or any combination thereof. In embodiments, the conjugated diene block includes a mixture of butadiene monomer and isoprene monomer. In embodiments, only 1,3-butadiene is used.

[0022] "Butadiene" refers to 1,3-butadiene.

[0023] "Monovylarene," "monoalkenylarene," or "vinyl aromatic" refers to an organic compound containing a single carbon-carbon double bond, at least one aromatic moiety, and a total of 8 to 18 carbon atoms, for example, 8 to 12 carbon atoms. Examples include styrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 2,4-dimethylstyrene, alpha-methylstyrene, vinylnaphthalene, vinyltoluene, vinylxylene, adamantylstyrene, vinylanthracene, or any mixture thereof. In embodiments, the monoalkenylarene block contains substantially pure monoalkenylarene monomers. In some embodiments, styrene is the main component having a trace proportion (less than 10% by weight) of structurally related vinyl aromatic monomers, such as o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 2,4-dimethylstyrene, alpha-methylstyrene, vinylnaphthalene, vinyltoluene, vinylxylene, or a combination thereof. In embodiments, only styrene is used.

[0024] "Residual unsaturation," or RU, refers to the level of unsaturation, i.e., the level of carbon-carbon double bonds per gram of block copolymer. RU can be measured using nuclear magnetic resonance or ozonolysis titration. RU can also be calculated by knowing the composition of the block copolymer.

[0025] "Vinyl content" refers to the amount of conjugated dienes polymerized via 1,2-addition in the case of butadiene or 3,4-addition in the case of isoprene, which result in monosubstituted olefins or vinyl groups adjacent to the polymer backbone. Vinyl content can be measured by nuclear magnetic resonance (NMR) spectroscopy.

[0026] The "coupling efficiency," expressed as %CE, is calculated using the weight percentages of the coupled and uncoupled polymers. The weight percentages of the coupled and uncoupled polymers are determined using the output of a differential refractometer detector. The signal intensity at a given elution volume is proportional to the amount of material with the molecular weight corresponding to the polystyrene standard detected at that elution volume. The area under the curve across the MW range corresponding to the coupled polymer is representative of the weight percentage of the coupled polymer, and similarly for the uncoupled polymer. %CE is given by multiplying by 100 (weight percentage of coupled polymer / weight percentage of coupled polymer + weight percentage of uncoupled polymer). Coupling efficiency can also be measured by calculating data from GPC and dividing the integrated area under the GPC curve for all coupled polymers (including copolymers such as 2-arm, 3-arm, and 4-arm) by the same integrated area under the GPC curve for both the coupled and uncoupled polymers.

[0027] "Coupling agent" or "X" refers to coupling agents commonly used in the production of styrene-based block copolymers (SBCs), such as silane coupling agents, polyvinyl compounds, polyvinylarenes, divinylarene compounds or multivinylarene compounds, diepoxides or multiepoxides, diisocyanates or multiisocyanates, dialkoxysilanes or multialkoxysilanes, diimines or multiimines, dialdehydes or multialdehydes, diketones or multiketones, alkoxytin compounds, dihalides or multihalides such as silicon halides and halosilanes, monoanhydrides, dianhydrides or multianhydrides, diesters or multiesters, etc.

[0028] The "polystyrene content" or PSC of an SBC refers to the weight percentage of vinyl aromatics, such as polystyrene, in the SBC, calculated by dividing the sum of the molecular weights of all vinyl aromatic blocks by the total molecular weight of the SBC. The PSC can be determined using proton nuclear magnetic resonance (NMR).

[0029] "Controlled distribution" is defined as referring to a molecular structure having the following attributes: (1) terminal regions adjacent to monoalkenylarene homopolymer ("A") blocks that are rich in conjugated diene units (i.e., have a greater-than-average amount of conjugated diene units), (2) one or more regions not adjacent to A blocks that are rich in monoalkenylarene units (i.e., have a greater-than-average amount of monoalkenylarene units), and (3) an overall structure having relatively low blocking, for example, less than 40. "Rich in" is defined as having a greater-than-average amount, for example, 5% more than the average amount. Relatively low blocking can be indicated by the presence of a single glass transition temperature ("Tg") intermediate to the Tg of any monomer alone, when analyzed using either differential scanning calorimetry ("DSC") or proton NMR. "Styrene blocking" can be measured using proton NMR and is defined as the proportion of monovinyl aromatic (S) units in a polymer having two S nearest neighbors on the polymer chain.

[0030] "Molecular weight" or "MW" refers to the styrene equivalent molecular weight in g / mol of a polymer block or block copolymer (unless otherwise specified). MW can be measured by gel permeation chromatography (GPC) using a polystyrene calibration standard, as performed by ASTM 5296-19. The GPC detector may be an ultraviolet detector, a refractive index detector, or a combination thereof. The chromatograph is calibrated using a commercially available polystyrene molecular weight standard. The MW of a polymer measured using such a calibrated GPC is the styrene equivalent molecular weight or apparent molecular weight. The MW as expressed herein is measured at the peak of the GPC trace and is generally referred to as the styrene equivalent "peak molecular weight," M p It is shown as follows.

[0031] M n This is the number average of molecular weights,

[0032]

number

[0033] "Main" means that, when used in combination with a composition and a particular component, such as a monomer, that component is present in the composition in a substantially pure form or in large quantities, for example, more than 80% by weight, or more than 85% by weight, or more than 90% by weight, or more than 95% by weight.

[0034] "Dispersed," "dispersion," or "emulsion" refers to a two-phase system in which one phase contains fine particles dispersed throughout a second phase, which is a bulk material. The particles are the dispersed phase or inner phase, and the bulk material is the continuous phase or outer phase. The continuous phase may be water, an aqueous mixture, or an organic mixture. "Dispersion" also means that not all of the composition or components necessarily have to be water-insoluble.

[0035] "Df" refers to the dissipation coefficient or loss tangent, which is a measure of the rate of electrical energy loss in a dissipative system.

[0036] "Dk" refers to the dielectric constant or dielectric constant.

[0037] An "electrochemical cell" is, for example, a positive electrode, a negative electrode, and ions (e.g., Na + Li + This refers to a “rechargeable battery” or “battery cell” that includes an electrolyte that conducts ) but electrically insulates the positive and negative electrodes from each other and is in direct contact with them. In embodiments, the battery may include multiple positive and / or multiple negative electrodes in a single container.

[0038] The "positive electrode" is where positive ions, such as lithium, are released during battery discharge. + This refers to the electrodes within a secondary battery that are reached by conduction, fluid flow, or movement.

[0039] The "negative electrode" or "anode" receives positive ions, such as lithium, during battery discharge. + This refers to the electrodes inside a secondary battery from which fluid flows or moves.

[0040] A "composite electrolyte" refers to an electrolyte having at least two components: a solid electrolyte and a binder that is bonded to or adhered to the electrolyte, or uniformly mixed with the electrolyte.

[0041] A "solid electrolyte" refers to a material suitable for electrically insulating the negative and positive electrodes, while also providing conduction pathways for ions such as lithium and sodium.

[0042] Anolite is the electrolyte on the anode side of an electrochemical cell. Anolite can be mixed with the anode material, layered on top of it, or laminated on top of it.

[0043] "Sulfide electrolytes" refer to inorganic solid materials that conduct ions but are substantially electronically insulating. Examples include lithium, phosphorus, and sulfur, as well as optionally additional elements such as Ge, Sn, Sn, As, Al, and Si.

[0044] "Binder" refers to a material that assists in the adhesion of another material and / or in the formation of a film, and a binder composition contains, essentially contains, or is derived from styrene block copolymer ("SBC").

[0045] This disclosure relates to a binder for use in rechargeable batteries, such as lithium-ion batteries. The polymer binder comprises a styrene-based block copolymer (SBC) having properties including high elasticity (lower hysteresis) to accommodate large volume expansion / contraction within the battery, along with high adhesive properties. In embodiments, the binder is incorporated into a unique structure for better performance in electrodes and / or electrolytes.

[0046] Styrene-based block copolymer (SBC): Unlike SBR, a random copolymer used as a binder material in conventional technology, SBC (styrene-based block copolymer) is a block copolymer. The rigid block (styrene) provides strength, while the flexible block (e.g., butadiene or isoprene) provides elasticity and adhesion. Due to its block structure, SBC inherently possesses better strength, elasticity, and adhesion than SBR in terms of battery characteristics, particularly charge / discharge cycle performance.

[0047] The SBC may be any of the linear, radial, or branched (multi-arm) block copolymers comprising at least one monovinyl aromatic block A, and at least one cyclic conjugated diene block and conjugated diene for block B, optionally comprising a coupling agent residue X. In embodiments, the SBC is unhydrogenated, hydrogenated, partially hydrogenated, or selectively hydrogenated. The SBC has a molecular weight of 30,000 to 1,000,000, or 35,000 to 750,000, or 40,000 to 500,000, or 50,000 to 200,000.

[0048] In the embodiment, block B is an unsaturated block that makes electron transfer more efficient than other types of polymers of the prior art such as SBR. In the embodiment, SBC has residual unsaturation of 0.5 to 25 meq / g, or has residual unsaturation of 0.5 to 20 meq / g, or has residual unsaturation of 1 to 18 meq / g, or has residual unsaturation of 2 to 15 meq / g, has residual unsaturation of less than 25 meq / g, or has residual unsaturation of less than 20 meq / g, or has residual unsaturation of less than 15 meq / g, or has residual unsaturation of less than 10 meq / g, or has residual unsaturation of less than 8 meq / g, or has residual unsaturation of less than 5 meq / g, or has residual unsaturation of less than 3 meq / g, or has residual unsaturation of more than 0.5 meq / g, or has residual unsaturation of more than 1 meq / g, or has residual unsaturation of more than 2 meq / g.

[0049] In the embodiment, the SBC has a polystyrene content of less than 40% by weight, or less than 35% by weight, or less than 30% by weight, or more than 5% by weight, or more than 10% by weight.

[0050] In the embodiment, SBC is sulfonated, i.e., has a sulfonate group, i.e., -SO3, in either the form of an acid (-SO3H, sulfonic acid) or a salt (-SO3Na). In the embodiment, block B comprises at least one of cyclohexadiene butadiene and isoprene block copolymer, and the polybutadiene and polyisoprene soft blocks may be hydrogenated, while the polycyclohexadiene block may be hydrogenated or not.

[0051] In embodiments, SBC is a sulfonated block copolymer as disclosed in U.S. Patents and Publication Nos. US20070021569A1, US10022680, US8263713, US9861941, US20130102213A1, and US20170107332A1, which are incorporated herein by reference. In embodiments, SBC is a selectively sulfonated negatively charged anionic styrene-based block copolymer. The term “selectively sulfonated” is defined as including sulfonic acids and neutralized sulfonate derivatives. The sulfonate group may be in the form of a metal salt, ammonium salt, or amine salt. In embodiments, the sulfonated block copolymer has a common composition ABA, (AB)n(A), (ABA)n, (ABA)nX, (AB)nX, ADB, ABD, ADBDA, ADBBA, (ADB)nA, (ABD)nA(ADB)nX, (ABD)nX, or a mixture thereof, where n is an integer from 0 to 30 or an integer from 2 to 20, and X is a coupling agent residue. Each A block and D block is a polymer block resistant to sulfonation. Each B block is susceptible to sulfonation. Multiple A blocks, B blocks, or D blocks may be identical or different.

[0052] Each A block comprises one or more segments selected from the polymerized (i) para-substituted styrene monomers, (ii) ethylene, (iii) alpha-olefins having 3 to 18 carbon atoms, (iv) 1,3-cyclodiene monomers, (v) monomers of conjugated dienes having a vinyl content of less than 35 mol percent prior to hydrogenation, (vi) acrylate esters, (vii) methacrylate esters, and (viii) mixtures thereof. In an embodiment, block A is selected from para-methylstyrene, para-ethylstyrene, para-n-propylstyrene, para-iso-propylstyrene, para-n-butylstyrene, para-sec-butylstyrene, para-iso-butylstyrene, para-t-butylstyrene, isomers of para-decylstyrene, isomers of para-dodecylstyrene, and mixtures thereof, which are para-substituted styrene monomers. Each B block comprises segments of one or more vinyl aromatic monomers. Each D block is selected from the group consisting of (i) polymerized or copolymerized conjugated dienes, (ii) polymerized acrylate monomers, (iii) polymerized silicon, (iv) polymerized isobutylene, and (v) mixtures thereof.

[0053] In an embodiment, block A has a relatively high glass transition temperature, for example, greater than 20 °C, or greater than 40 °C, or greater than 50 °C, or greater than 60 °C, or greater than 80 °C, or greater than 100 °C, or a relatively high glass transition temperature of 30 to 100 °C, or a relatively high glass transition temperature of 40 to 80 °C, compared to other polymer blocks in the SBC, thereby resulting in a copolymer having desired mechanical properties and other functional properties. In an embodiment, block A has a molecular weight (M p ) of 1,000 to 60,000 g / mol, or a molecular weight (M p ) of 2,000 to 50,000 g / mol, or a molecular weight (M p ) of 5,000 to 45,000 g / mol, or a molecular weight (M p) has, or has a molecular weight (M) of 10,000 to 35,000 g / mol p ) has or has a molecular weight (M) greater than 1500 g / mol p ) has or has a molecular weight (M) less than 50,000 g / mol p ) has. In an embodiment, block A constitutes 1 to 80% by weight, or 5 to 75% by weight, or 10 to 70% by weight, or 15 to 65% by weight, or 20 to 60% by weight, or 25 to 55% by weight, or 30 to 50% by weight, or more than 10% by weight, or less than 75% by weight, based on the total weight of SBC. In an embodiment, block A has 0 to 25% by weight, or 2 to 20% by weight, or 5 to 15% by weight of vinyl aromatic monomers, such as those present in block B. In an embodiment, block A has a degree of sulfonation of 0 to 15 mol%, or 2 to 12 mol%, or 5 to 10 mol%.

[0054] In the embodiment, block B comprises polymerization units of vinyl aromatic monomers selected from unsubstituted styrene, orthosubstituted styrene, metasubstituted styrene, alpha-methylstyrene, 1,1-diphenylethylene, 1,2-diphenylethylene, and mixtures thereof. In the embodiment, block B has a degree of sulfonation of 10 to 100 mol% of sulfonic acid or sulfonic acid ester functional groups, or a degree of sulfonation of 15 to 95 mol%, or a degree of sulfonation of 20 to 90 mol%, or a degree of sulfonation of 25 to 85 mol%, or a degree of sulfonation of 30 to 80 mol%, or a degree of sulfonation of 35 to 75 mol%, or a degree of sulfonation of 40 to 70 mol%, or a degree of sulfonation of more than 15 mol%, or a degree of sulfonation of less than 85 mol%, based on the number of monomer units or blocks to be sulfonated. In the embodiment, block B has a molecular weight (M) of 10,000 to 300,000 g / mol. p ) has, or has a molecular weight (M) of 20,000 to 250,000 g / mol p) has, or has a molecular weight (M) of 30,000 to 200,000 g / mol p ) has, or has a molecular weight (M) of 40,000 to 150,000 g / mol p ) has, or has a molecular weight (M) of 50,000 to 100,000 g / mol p ) has, or has a molecular weight (M) of 60,000 to 90,000 g / mol p ) has or has a molecular weight (M) greater than 15000 g / mol p ) has or has a molecular weight (M) less than 150,000 g / mol p ) has. In an embodiment, block B constitutes 10 to 80% by weight, or 15 to 75% by weight, or 20 to 70% by weight, or 25 to 65% by weight, or 30 to 55% by weight, or more than 10% by weight, or less than 75% by weight, based on the total weight of SBC. In an embodiment, block B has 0 to 25% by weight, or 2 to 20% by weight, or 5 to 15% by weight of parasubstituted styrene monomers, such as those present in block A.

[0055] In embodiments, block D comprises polymers or copolymers of conjugated dienes selected from isoprene, 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 1-phenyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, 3-butyl-1,3-octadiene, farnesene, myrcene, piperylene, cyclohexadiene, and mixtures thereof. In this embodiment, block D has an Mp of 1,000 to 60,000 g / mol, or an Mp of 2,000 to 50,000 g / mol, or an Mp of 5,000 to 45,000 g / mol, or an Mp of 8,000 to 40,000 g / mol, or an Mp of 10,000 to 35,000 g / mol, or an Mp of 15,000 to 30,000 g / mol, or an Mp greater than 1,500 g / mol, or an Mp less than 50,000 g / mol. In this embodiment, block D constitutes 10 to 80% by weight, or 15 to 75% by weight, or 20 to 70% by weight, or 25 to 65% by weight, or greater than 10% by weight, or less than 75% by weight, based on the total weight of the SBC.

[0056] In the embodiment, sulfonation occurs mainly at the para position relative to the phenyl carbon atom bonded to the polymer backbone in the phenyl ring of the polymerized styrene unit in block B. In the embodiment, block B has a degree of sulfonation of 10 to 100 mol% of sulfonic acid or sulfonic acid ester functional groups, or a degree of sulfonation of 15 to 95 mol%, or a degree of sulfonation of 20 to 90 mol%, or a degree of sulfonation of 25 to 85 mol%, or a degree of sulfonation of 30 to 80 mol%, or a degree of sulfonation of 35 to 75 mol%, or a degree of sulfonation of 40 to 70 mol%, or a degree of sulfonation of more than 15 mol%, or a degree of sulfonation of less than 85 mol%, based on the number of monomer units or blocks to be sulfonated. In the embodiment, the sulfonated polymer has a sulfonation degree of more than 25 mol%, or more than 50 mol%, or less than 95 mol%, or between 25 and 70 mol%. The sulfonation degree can be calculated by NMR or ion exchange capacity (IEC).

[0057] In the embodiment, SBC is a mid-block sulfonated triblock copolymer or a mid-block sulfonated pentablock copolymer, for example, poly(p-tert-butylstyrene-b-styrenesulfonate-bp-tert-butylstyrene) or poly[tert-butylstyrene-b-(ethylene-alt-propylene)-b-(styrenesulfonate)-b-(ethylene-alt-propylene)-b-tert-butylstyrene].

[0058] In this embodiment, the sulfonated block copolymer has a molecular weight of 25,000 to 500,000. p Having, or M p Having, or M p Having, or M p Having, or 45,000 to 300,000 M p Having, or M pHaving or exceeding 35,000 M p M has or has less than 350,000 g / mol p In an embodiment, the SBC has an ion exchange capacity (IEC) greater than 0.5 meq / g, or greater than 0.75 meq / g, or greater than 1.0 meq / g, or greater than 1.5 meq / g, or greater than 2.0 meq / g, or greater than 2.5 meq / g, or less than 5.0 meq / g. In an embodiment, the SBC has a pH less than 6, or less than 5, or less than 4, or less than 3, or less than 2.75, or less than 2.5, or less than 2.25, or less than 2, or less than 1.75, or less than 1.5, or less than 1.25.

[0059] In embodiments, the SBC is a non-hydrogenated blocker polymer, such as that disclosed in U.S. Patent No. US7704676, which is incorporated herein by reference. The non-hydrogenated blocker polymer in embodiments has a general structure AIBIA or (AIB)nX. Each A block is independently a vinyl aromatic compound. Each I is mainly isoprene. Each B is mainly butadiene. X is a coupling agent residue, and n is an integer of 2 or more. In embodiments, the weight ratio of I to B is in the range of 30:70 to 70:30. The B block has a 1,2-vinyl bond content in the range of 20 to 90%, or at least 30%. The PSC is 10 to 45%, or 15 to 35%, or at least 25%. Block A has a molecular weight in the range of 5,000 to 20,000, or 5,000 to 15,000, or 10,000 to 20,000. Blocks I and B together have a molecular weight in the range of 50,000 to 200,000, or 100,000 to 200,000, or 50,000 to 150,000. In the embodiment, the AIB content, which is a non-conjugated triblock, is in the range of about 2% to about 95%, or at least 90%.

[0060] In embodiments, the SBC is in the form of an aqueous dispersion such as an isoprene rubber latex, having two or more polystyrene blocks containing less than 5% by weight of copolymerizable monomers based on the weight of the polystyrene block, and at least one block of polyisoprene containing less than 5% by weight of copolymerizable monomers based on the weight of the block polymerization conjugated diene. The SBC has a weight-average MW of 170,000 to 350,000, or 180,000 to 300,000, or at least 200,000, or less than 275,000. The polystyrene block has a weight-average MW of 8,000 to 15,000, and the PSC in the block copolymer is 5 to 25% by weight. Each B block consists of isoprene, and its weight-average MW is 30,000 to 200,000, or less than 150,000, or less than 100,000, or 40,000 to 70,000.

[0061] In embodiments, the SBC comprises at least two blocks (A) of polymerized monoalkenylarenes and at least one block (B) of polymerized conjugated dienes, as disclosed in U.S. Patent Publication No. US202010394404, incorporated herein by reference, wherein these blocks are arranged linearly or radially. In embodiments, the SBC has a common arrangement such as ABA or ABX-(BA)n [wherein X represents a residue of the coupling agent, and n is an integer of 2 or more, representing the average number of arms in the radial structure]. In embodiments, the coupling efficiency is greater than 90%, or 92–100%. In the radial block copolymer structure, block A has 10,000–12,000 MW. Block B has 75,000–150,000 MW, or 80,000–120,000 MW. The total amount of A blocks in the completed block polymer is 8-15% by weight or 10-12% by weight. In the linear block copolymer, each A block has 8,000-15,000 MW or 9,000-14,000 MW. The total molecular weight of the block copolymer is 150,000-250,000 or 170,000-220,000. The block copolymer has a monoalkenylarene content of 8%-15% by weight or a monoalkenylarene content of 9%-14% by weight, based on the total weight of the block copolymer. In the embodiment, the copolymer is a SIS (styrene-isoprene-styrene) block copolymer containing 15-30% by weight of styrene and 70-85% by weight of isoprene, and having a molecular weight of 30,000-200,000 MW. In embodiments, the copolymer has the formula AB-Xm-(BA)n, where A, B, X, and n are as previously defined, A has 8,000 to 15,000 MW, B has 30,000 to 200,000 MW, m is 0 or 1, and n is an integer from 1 to 5. In embodiments, the copolymer is a mixture containing 60% to 10% by weight of a radial styrene-based block copolymer and 40% to 90% by weight of a styrene diene diblock copolymer.Styrene diblock copolymers are styrene isoprene diblock copolymers and / or styrene butadiene diblock copolymers. When the diblock copolymer is styrene butadiene diblock copolymer, it has 10 to 30% by weight of PSCs.

[0062] In embodiments, SBC is a linear block copolymer of formula ABA. Each B block is mainly butadiene. Each A block is monovinyl aromatic. PSC is in the range of 20-50%, or 25-40%, or at least 30%. MW is in the range of 50,000-200,000%, or 110,000-175,000%, or at least 125,000. Vinyl bond content is in the range of 20-60%, or at least 25%, or 35-50%. Triblock content is at least 85%, or at least 90%.

[0063] In embodiments, SBC is a non-hydrogenated radial block copolymer having a general structure (AB)nX, where n is in the range of 3 to 4 and X is a coupling agent residue. Block A is a monovinyl aromatic polymer block. Block B is a conjugated diene polymer block. The PSC content is in the range of 20 to 30%. In embodiments, SBC has 250,000 to 400,000 MW, or 300,000 to 370,000 MW.

[0064] In embodiments, SBC is a block copolymer having at least one A block and at least one B block, as disclosed in U.S. Patent No. 7169848, incorporated herein by reference. In embodiments, SBC has a general composition of AB, ABA, (AB)n(ABA)n(ABA)nX, (AB)nX, or mixtures thereof, where X is a coupling agent residue and n is an integer from 2 to about 30. In embodiments, SBC is a tetrablock having the structure A1-B1-A2-B2. Each A, A1, and A2 block is a monoalkenylarene polymer block. Each B and B1 block is a controlled distribution copolymer block of at least one conjugated diene and at least one monoalkenylarene. Each B2 block is selected from the group consisting of (i) a controlled distribution copolymer block of at least one conjugated diene and at least one monoalkenylarene, (ii) a homopolymer block of a conjugated diene, and (iii) a copolymer block of two or more different conjugated dienes. Each A, A1, and A2 block independently has 3,000 to 60,000 MW. Each B and B1 block independently has about 30,000 to about 300,000 MW. Each B2 block independently has 2,000 to 40,000 MW. Each B and B1 block includes a terminal region adjacent to an A block rich in conjugated diene units and one or more regions not adjacent to an A block rich in monoalkenylarene units. In embodiments, the block copolymer further includes at least one C block. Each C block is a polymer block of one or more conjugated dienes, each having 2,000 to 200,000 MW. The total amount of monoalkenylarenes in the block copolymer is 20% to 80% by weight. The total amount of monoalkenylarenes in each B and B1 block is 10% to 75% by weight. In embodiments, following hydrogenation, 0 to 10% of the arene double bonds are reduced and at least 90% of the conjugated diene double bonds are reduced. If desired, blocks A and A1 may be fully saturated so that at least 90% of the arene double bonds are reduced.Furthermore, if desired, the saturation of the diene block may be reduced so that 25-95% of the diene double bonds are reduced.

[0065] In embodiments, SBC is a hydrogenated block copolymer of the formula ABA, (AB)nX, where X is a coupling agent residue and n has a value of 3. Before hydrogenation, each B block is a polymer of conjugated dienes and each A block is a polymer of vinyl aromatics. PSC is in the range of 13–25%, or 20–23%, or greater than 18%. MW is in the range of 100,000–200,000%, or 110,000–175,000, or greater than 125,000. Vinyl bond content is in the range of 60–90%, or greater than 60%, or greater than 65–75%.

[0066] In embodiments, SBC is a hydrogenated or unhydrogenated block copolymer containing 1,3-cyclohexadiene monomer (CHD). In embodiments, the SBC containing CHD has the following general configurations: AB, (AB)nX, A'-B, (A'-B)nX, ABA, A'-B-A', AB-A', or ABC [wherein n is an integer from 2 to 30, and X is a coupling agent residue]. Each A block is a poly(1,3-cyclodiene) homopolymer. Each A' block is a poly(1,3-cyclodiene-co-monoalkenylarene) random copolymer. Each B block is a poly(acyclic conjugated diene) polymer containing at least one acyclic conjugated diene polymerization unit. In embodiments, the B block is hydrogenated. Each C block is a poly(alkenylarene) polymer. Each of blocks A, A', and C independently has an average molecular weight of 2,000 to 60,000, or independently has an average molecular weight of 2,500 to 50,000, or independently has an average molecular weight of 3,000 to 30,000. Each of blocks B has an average molecular weight of 1,000 to 300,000, or independently has an average molecular weight of 2,000 to 100,000, or independently has an average molecular weight of 2,500 to 75,000, or independently has an average molecular weight of 3,000 to 50,000.

[0067] In embodiments, SBC is a poly(1,3-cyclohexadiene) homopolymer, such as that disclosed in U.S. Patent Publication No. 2021-0309773, which is incorporated herein by reference. In embodiments, SBC has Mn of 2,000 to 15,000, or 3,500 to 12,500, or 5,000 to 10,000, or more than 2,000, or more than 3,000, or more than 5,000, or less than 15,000, or less than 10,000. In embodiments, SBC has MW of 5,000 to 15,000, or MW of 7,000 to 12,000, or less than 10,000, or more than 6,000, or more than 4,000. In the embodiment, the SBC has a polyvariance index of 3.0 to 8.0, or a polyvariance index of 4.0 to 6.0, or a polyvariance index greater than 4.5, or a polyvariance index less than 7.0, or a polyvariance index of 3.5 to 7.0.

[0068] In embodiments, SBC is a copolymer formed by cationic polymerization of one or more cyclic dienes and comonomers, as disclosed in U.S. Patent Publication No. 2021-0309779, which is incorporated herein by reference. The comonomers are selected from the group consisting of monoterpenes, branched styrenes, and combinations thereof. The one or more cyclic dienes are selected from the group consisting of 1,3-cyclohexadiene (CHD), cyclopentadiene (CPD), 1,3-cycloheptadiene, 4,5,6,7-tetrahydroindene, norbornadiene (NBD), and combinations thereof. In one embodiment, the SBC has Mn between 2,000 and 15,000, or Mn between 3,500 and 12,500, or Mn between 5,000 and 10,000, or Mn greater than 2,000, or Mn greater than 3,000, or Mn greater than 5,000, or Mn less than 15,000, or Mn less than 10,000. In another embodiment, the SBC has Mz between 2,000 and 30,000, or Mz between 3,000 and 25,000, or Mz less than 20,000, or Mz less than 18,000, or Mz greater than 2,500, or Mz greater than 3,000.

[0069] In embodiments, SBC is a star-branched copolymer as disclosed in U.S. Patent Publication No. 2020-0347168, which is incorporated herein by reference. Each polymer arm comprises polymerization unit (i), which is a polymerization unit (i) derived from a first vinyl aromatic monomer containing a radical reactive group, wherein more than 10 mol% to 100 mol% of polymerization unit (i) is unhydrogenated; and polymerization unit (ii), which optionally includes (iiA) hydrogenated and unhydrogenated forms of polymerization unit (ii) derived from a high Tg monomer having a Tg of 300°C or less, and (iiB) a hydrogenated form of polymerization unit (i) or a hydrogenated form of polymerization styrene unit; and optionally includes polymerization unit (iii), which optionally includes (iiiA) a hydrogenated form of polymerization unit derived from one or more acyclic conjugated dienes, wherein less than 10 wt% of (a) is unhydrogenated, and (iiiB) polymerization units derived from one or more second vinyl aromatic monomers. Each polymer arm of the star-shaped branched polymer has a molecular weight Mp ranging from 1 kg / mol to 50 kg / mol. The copolymer has a peak molecular weight Mp ranging from 15 kg / mol to 500 kg / mol.

[0070] In the embodiment, the SBC is further modified (functionalized) by a grafting reaction using a functional group chemically bonded to either the styrene or the ethylene-butylene block chemical functional moiety.

[0071] In embodiments, the functional group is an unsaturated monomer or derivative thereof having one or more saturated groups, such as carboxylic acid groups and their salts, anhydrides, esters, imides, amides, or acid chloride groups, as disclosed in U.S. Patent Nos. US7169848, US4578429, US5506299, and US4292414, which are incorporated herein by reference. Examples include quaternary ammonium salts, carboxylic acids / salts, maleic acid, fumaric acid, itaconic acid, citraconic acid, acrylic acid, glycidyl acrylate, cyanoacrylate, and hydroxy C1-C12. 20This product contains alkyl methacrylate, acrylic polyether, acrylic anhydride, methacrylic acid, crotonic acid, isocrotonic acid, mesaconic acid, angelic acid, maleic anhydride, itaconic anhydride, citraconic anhydride, acrylonitrile, methacrylonitrile, sodium acrylate, calcium acrylate, and magnesium acrylate.

[0072] In embodiments, the functional groups for grafting are selected from silanes, sulfonic acids, phosphates, phosphine oxides, phosphoric acids, alkoxides, nitriles, thioethers, thiols, and combinations thereof. In embodiments, the SBC is modified by a grafting reaction with a silicon or boron-containing compound, as taught in U.S. Patent No. 4,882,384, incorporated herein by reference. One example is a grafting reaction with an alkoxysilane compound to form a silane-modified block copolymer. In embodiments, the SBC is an epoxidized block copolymer, as disclosed in U.S. 8927657B2, incorporated herein by reference, where the double bonds of the conjugated diene groups are epoxidized.

[0073] SBC is available for use in binders in various forms, including but not limited to powder, pellet, crumb, solution, gel, membrane or film, suspension, aqueous dispersion, aqueous emulsion, or latex. In embodiments, SBC is used in aqueous suspension or latex form, and the polymer has reduced particle size, for example, in the range of microns and submicrons.

[0074] In the embodiment, the SBC has a particle size of 0.05 to 20.0 μm, or 0.05 to 15 μm, or 0.1 to 10 μm, or 0.2 to 5 μm, or 0.2 to 5 μm, or 0.5 to 3 μm. Smaller particle sizes may exhibit better adhesion and surface / crack protection for electrode particles such as Si or Si alloys, Si compounds, or Si composites.

[0075] In the embodiment, the amount of SBC polymer within the binder range is greater than 20% by weight, greater than 30% by weight, greater than 40% by weight, or 20-99% by weight, or 25-95% by weight, or 30-90% by weight, or 35-85% by weight, based on the total weight of the binder composition.

[0076] Optionally modified SBCs. In embodiments, the SBCs are first suspended in a solvent to form a colloidal suspension, and then optionally doped or grafted with chemical dopants to increase conductivity, for example, by increasing the local concentration of ions present in the conduction domains of the polymer. In embodiments, the chemical dopants include ionic liquids, such as heterocyclic diazole ionic liquids, imidazole-type cations, alkyl-substituted imidazolium, pyridinium, pyrrolidinium cations, or combinations thereof. The amount of polymerized ionic liquid blocks in embodiments is in the range of 5 to 70 mol% of the total SBC, or at least 10 mol%.

[0077] In some embodiments, the SBC contains CHD(1,3-cyclohexadiene), and the SBC can be made intrinsically conductive by dehydrogenating PCHD(poly(1,3-cyclohexadiene)) to a conjugated polymer or semiconductor polymer, i.e., polyphenylene. In other embodiments, the SBC is made intrinsically conductive by graft copolymerization with aniline on a polystyrene block. The aniline polymer, which is a conjugated homopolymer or copolymer consisting of at least one unsubstituted aniline and / or substituted aniline, is in embodiments doped with a protonic acid, which functionalizes the aniline polymer so that it is melt-processable or solution-processable and suitable for grafting.

[0078] Alternatively or additionally, in embodiments, the SBC is doped with a conductive filler, or made conductive with a conductive filler. In embodiments, the conductive filler includes particles of pure silver powder, acetylene carbon, carbon black, graphene, metal particles or mixtures thereof whose surfaces are coated with silver, graphite, natural graphite, silver-coated graphite particles, nickel-coated graphite particles, gold-coated graphite particles or mixtures thereof. The particles have a median mass diameter (D50) of about 100 microns and are selected from the group consisting of flakes, plates, leaf-like particles, rods, tubes, fibers, needles and dendritic particles. In embodiments, the conductive filler consists of carbon fibers having a length of 5 to 100 microns.

[0079] In embodiments, the conductive filler is a carbon-based nanofiller, such as a carbon nanotube (CNT). The CNT can be dispersed in SBC via methods known in the art, for example, U.S. Patent Publication Nos. US20040186220A, US-2010 / 0009165-A and WO-2010 / 007163-A, which are incorporated herein by reference. Known methods include, but are not limited to, solvent-assisted polymer coating / wrapping processes and non-wrapping processes.

[0080] In the embodiment, the amount of conductive filler is in the range of 0.1 to 20% by weight, 0.1 to 15% by weight, 1 to 10% by weight, or less than 8% by weight, or greater than 1% by weight, of the total weight of the binder composition. In the embodiment, the amount of conductive filler is present in a weight ratio of conductive filler to SBC of 1:50 to 1:4, or in a weight ratio of conductive filler to SBC of 1:40 to 1:30, or in a weight ratio of conductive filler to SBC of 1:30 to 1:5, or in a weight ratio of conductive filler to SBC of 1:20 to 1:6, or in a weight ratio of conductive filler to SBC of 1:10 to 1:8.

[0081] In embodiments, in addition to or instead of being modified with a conductive filler, the SBC is modified by the addition of IR rubber latex to improve binder properties, such as adhesion and elasticity. In embodiments, the SBC modified with IR rubber latex is present in an amount of 10 to 20% by weight, or less than 20% by weight, or less than 15% by weight, or less than 10% by weight, based on the whole electrode composition.

[0082] In embodiments, instead of or in addition to IR rubber latex, SBC is modified with silicone to further improve adhesion and elasticity. In embodiments, the silicone-modified SBC is present in an amount of 10-20% by weight, or less than 20% by weight, or less than 15% by weight, or less than 10% by weight, based on the whole electrode composition.

[0083] Optional Tackifying Resin Component: In some embodiments, depending on the application, the binder composition optionally includes a tackifying resin. In embodiments, the tackifying resin includes a rosin resin selected from the group of modified rosin resins and rosin esters. The modified rosin resin includes one or more components selected from the group of rosin acid, maleic anhydride or fumaric acid or maleic acid modified rosin ester (MMRE). Rosin acid derived from trees as gum rosin, wood rosin or tall oil rosin consists of one or more components from the group consisting of abietic acid, neoabietic acid, dehydroabietic acid, levopimalic acid, pimaric acid, pulsed phosphoric acid, isopimaric acid and sandalocopymaric acid. Rosin esters consist of one or more derivatives obtained by the reaction of one or more rosin acids with one or more alcohols from the group consisting of methanol, triethylene glycol, glycerol and pentaerythritol.

[0084] In some embodiments, the rosin ester resin is selected from hydrogenated hydrocarbon rosin esters, acrylic rosin esters, disproportionated rosin esters, dibasic acid-modified rosin esters, polymerized resin esters, phenol-modified rosin ester resins, and mixtures thereof. In other embodiments, the binder includes a mixture of maleic acid-modified glycerol ester and pentaerythritol ester of the rosin resin.

[0085] In embodiments, the binder includes a hydrocarbon resin as a tackifier. Examples include resins selected from the group consisting of C5 aliphatic hydrocarbon resins, C9 aromatic hydrocarbon resins, and C5 / C9 hydrocarbon blends. C5 aliphatic hydrocarbon resins are produced by the distillation reaction of piperylene containing one or more components from the group consisting of trans-1,3-pentadiene, cis-1,3-pentadiene, 2-methyl-2-butene, dicyclopentadiene, cyclopentadiene, and cyclopentene, in the presence of a Lewis catalyst. C9 aromatic hydrocarbon resins are byproducts of naphtha cracking of petroleum raw materials used to produce C5 aliphatic resins containing one or more components from the group consisting of vinyltoluene, dicyclopentadiene, indene, methylstyrene, styrene, and methylindene.

[0086] In embodiments, the tackifying resin is selected from the group consisting of maleated rosin esters, maleic acid-modified glycerol rosin esters, fumarated rosin esters, acrylic rosin esters, amidated rosin esters (amine-modified), nitrated rosin esters, chlorinated rosin esters, brominated rosin esters, pentaerythritol esters of hydrogenated rosin, glycerol esters, hydrocarbon esters such as piperienes and isoprene which are both hydrogenated and non-hydrogenated, styrene hydrocarbon resins, and terpene resins such as terpene phenols, styrene terpenes, and polyterpene resins, as well as mixtures thereof.

[0087] In the embodiment, the tackifying resin is provided in an aqueous dispersion. In the embodiment, the aqueous dispersion of the tackifying resin contains a surfactant. Any desired surfactant, such as anionic surfactants, cationic surfactants, nonionic surfactants, or mixtures thereof, can be used to prepare the aqueous tackifying agent dispersion.

[0088] In the embodiment, the tackifying resin has a particle size of 0.3 to 3 μm, or a particle size of 0.5 to 1.5 μm, or a particle size of less than 3 μm, or a particle size greater than 0.3 μm, or a particle size greater than 0.5 μm.

[0089] In embodiments, the amount of optional tackifying resin in the binder is in the range of 0 to 70% by weight, less than 30% by weight, or in the range of 20 to 70% by weight, or in the range of 25 to 50% by weight, or greater than 10% by weight, or greater than 5% by weight, based on the total weight of the adhesive composition. In embodiments, the resin tackifier to SBC in the binder composition is present in a weight ratio range of 10:90 to 50:50, or in a weight ratio range of 20:80 to 80:20, or in a weight ratio range of 20:80 to 40:60, or in a weight ratio range of 45:50 to 40:60.

[0090] Optional plasticizer component: Depending on the application, in some embodiments the binder further comprises at least one plasticizer selected from the group consisting of vegetable oils, process oils, mineral oils, phthalates, and mixtures.

[0091] Process oils consist of one or more components from the group comprising paraffinic oils, naphthenic oils, and aromatic oils. Paraffinic oils have a saturated carbon skeleton, naphthenic oils have a polyunsaturated carbon structure with little aromatic content, and aromatic oils have cyclic carbon unsaturation, which gives them their aromatic classification.

[0092] The amount of plasticizer in the binder is in the range of 0 to 40% by weight, or 5 to 35% by weight, or less than 20% by weight, based on the total weight of the binder material.

[0093] Characteristics: In embodiments, SBC has a fracture elongation of over 400% (according to ASTM D412), or over 600% (according to ASTM D412), or over 800% (according to ASTM D412), or 200-2,000% (according to ASTM D412), or 400-2,000% (according to ASTM D412), or less than 2,000% (according to ASTM D412), enabling the binder material to have high elasticity (low hysteresis). Due to its high elasticity, when SBC is used as a binder material for addition to anodes, such as silicon anodes, the binder helps to reduce charging and discharging stresses while holding silicon particles together. Binders containing SBC are characterized by being elastic, having low stress relaxation, high strength, and high fracture elongation.

[0094] In the embodiment, the SBC is measured by dynamic mechanical analysis (DMA) according to ASTM 4065 and has the lowest possible glass transition temperature (Tg) in the range of 30 to 90°C, or the lowest possible glass transition temperature (Tg) in the range of 40 to 90°C, or the lowest possible glass transition temperature (Tg) in the range of 50 to 80°C, or the lowest possible glass transition temperature (Tg) in the range of 60 to 80°C, or the lowest possible glass transition temperature (Tg) greater than 30°C, or the lowest possible glass transition temperature (Tg) less than 95°C, or the lowest possible glass transition temperature (Tg) less than 80°C.

[0095] In embodiments, the SBC has an insulation constant (Dk) of 2.2 to 3, or an insulation constant (Dk) of 2.2 to 2.8, or an insulation constant (Dk) of 2.2 to 2.5. In embodiments, the SBC has a dissipation coefficient (Df) of 0.001 to 0.01, or an insulation constant (Df) of 0.001 to 0.05, or an insulation constant (Df) of 0.001 to 0.001, or an insulation constant (Df) of 0.001 to 0.005. Dk and Df are measured at 1 GHz and 20 GHz by ASTM D2520.

[0096] In embodiments, the SBC for use in binder compositions is not crosslinked (unlike prior art binder materials, e.g., SBR). In embodiments, the SBC is substantially gel-free, for example, having a gel content of less than 10%, or less than 5%, or less than 2%, or less than 1%. Gel refers to a soft, semi-solid, or solid state, or a material such as, for example, as a result of crosslinking.

[0097] In some embodiments, the SBC is provided in the form of an aqueous dispersion that is essentially free of or does not contain organic solvents.

[0098] In the embodiment, the binder material containing SBC is characterized by having any of the following: high mechanical strength, high adhesion to electrode particles and fillers, high electrical conductivity, high ionic conductivity, or a combination thereof.

[0099] Binder materials containing SBCs can be melt-extruded at low temperatures, even with the addition of Si or Si alloys, Si compounds or Si composites, carbon black, or graphite slurry. These materials exhibit good chemical resistance to acids and bases. Polar functional groups can be introduced into the binder using functionalized / grafted SBCs.

[0100] Methods and applications for preparing binder materials: Binder materials containing SBCs are suitable for use in batteries such as lithium-ion batteries and lithium-sulfur batteries, regardless of whether they are Si-based or C-based. Binder materials containing SBCs can be used to form electrodes, such as positive and negative electrodes, solid electrolytes, and anolites.

[0101] The method for producing a binder material containing SBC depends on the end-use application, e.g., electrodes or anolites; the materials used in the electrodes, e.g., graphite, carbon black, Li, Al, Si, Si alloys, Si composites, e.g., lithium transition metal oxides, titanium oxide, nanographite, boron, boron carbide, silicon carbide, rare earth metal carbides, transition metal carbides, boron nitride, silicon nitride, rare earth metal nitrides and transition metal nitrides; and the components that should be included in the binder material to address factors such as energy density and volume expansion.

[0102] In embodiments, the binder material containing SBC is for forming “elastic” anolite. Elasticity indicates that it is compressible without breaking or flexible. In embodiments, the binder material containing SBC, particularly conductive SBC, is incorporated into a liquid gel together with other materials, such as carbon, nanoparticles (e.g., Ag, Mg, Si, Ni, Cu, Pt, C, etc. and combinations), nanowires, etc., to form a network of electrically conductive species and elastic anolite. The elastic anolite layer is more compressible during Li stripping compared to hard or rigid anolite. With the SBC binder material, the elastic anolite has some ability to deform without degradation and maintains mechanical integrity with deformation (compared to hard anolite which cracks or breaks with moderate deformation). In embodiments, about 90% of the anolite composition containing the SBC binder material remains after being subjected to about 20% deformation over 500 cycles.

[0103] In embodiments, SBC is first mixed with a solid inorganic electrolyte, such as a lithium superionic conductor, lithium phosphate nitride, polyethylene glycol (PEG), polyethylene oxide / polypropylene oxide, sulfide electrolyte, fish oil, phosphate ester, and other dispersants, in a solvent such as acetonitrile, succinonitrile, toluene, benzene, ethyl ether, decane, undecane, dodecane, and mixtures thereof, to form a slurry into a "green film" (before heat treatment). In some examples, the film is extruded in layers or deposited or laminated on other composite electrolytes to construct several layers of a composite electrolyte. In embodiments, the film is sintered by heating the electrolyte film or powder in the range of about 5°C to about 1200°C for about 1 to about 720 minutes. The electrolyte film in embodiments has a thickness of more than 10 nm and less than 100 μm.

[0104] In embodiments, the SBC aqueous dispersion and the tackifying resin aqueous dispersion are combined before other components are added to form a binder. In embodiments, the binder composition containing SBC and other components, such as a conductive material, is dispersed in water for subsequent film formation, for spraying as a coating, or for lamination onto a composite electrolyte or collector substrate to form electrodes. After coating, the battery electrodes may be dried in a vacuum chamber or in an inert gas atmosphere.

[0105] In embodiments, a binder containing SBC is applied to better control volume expansion by surrounding the Si particles and to restore electrode particles, such as Si or Si alloys, Si compounds or Si composites, carbon black, graphite, etc., to (almost) their original physical state after each charge / discharge cycle, thereby minimizing capacity degradation. Any silicon particle size may be useful, but in some embodiments, this is 2 nm to 100 micrometers, or 0.1 nm to 1000 μm, or an average diameter of 50 to 100 nm.

[0106] In embodiments using sulfonated block copolymers, for example, SBC binder materials containing Kraton Corporation's Nexar® sulfonated polymer, a universal rolling press method is used by rolling the sulfonated block copolymer in film form onto a current collector, followed by heat treatment to obtain an electrode.

[0107] In one embodiment, an SBC material, such as Nexar® sulfonated polymer, is electrospinned into fibers. During pressing, the fibers adhere strongly to a current collector (e.g., Cu foil). After heat treatment / carbonization, the Cu foil forms a strong bond with the SBC material. In another embodiment, electrode particles are combined with the polymer before electrospinning to form a polymer composite. In another embodiment, the two-component composite (electrode particles and SBC) can be made into fibers by extrusion fiber spinning into a hollow fiber structure.

[0108] In other embodiments, slurries, solutions, polymer melts, dispersions, emulsions, etc., are co-extruded into other types of structures together with a binder composition containing electrode material as the main component (85-98% by weight) and binders and conductive additives as minor components (1-10% by weight). After extrusion, the fibers may be dried (if necessary) and cut to the desired length. The aforementioned hollow segmented structure is one of many structures that can be used, but other structures, such as tipped trefoil, sea core, shell core fibers, and islands in sea fibers, are also available. [Modes for carrying out the invention]

[0109] example The following illustrative examples summarized in Table 1 are non-exclusive.

[0110] In the comparative example, SBR is a styrene-butadiene-rubber binder for Li-ion battery anodes, commercially available from MTI Corporation, in emulsion form with a viscosity of 100-250 mPa·s (NDJ-5S, 25°C), containing 23-35% styrene, 70-72% butadiene, and 5% carboxyl. CMC is carboxymethylcellulose, also from MTI Corporation, in powder form with a viscosity-average molar mass or Mv of 400,000.

[0111] Comparative Example 1 The active anode material (graphite), conductive additive (carbon black), and CMC are first mixed at a high shear rate to achieve a smooth paste. The shear rate is then reduced to less than 100 1 / s, and SBR latex is added to the paste. The paste is then coated onto Cu foil using a doctor blade coating method. The dry composition of the electrode is as follows: graphite 94%, carbon black 2%, CMC 1.5%, and SBR 2.5%.

[0112] Comparative Example 2 This is the same as Comparative Example 1, except that the electrode is composed of 89% graphite and 5% micron-sized silicon. [Examples]

[0113] [ Examples 1-10The SBC binders used in the example are listed in Table 1. First, the SBC binder is dissolved in toluene. The amount of toluene is adjusted so that the final paste has a viscosity of approximately 3,000 cP. After dissolving the SBC binder in toluene, the active anode material (multiple) (graphite or graphite + Si) and conductive additive (carbon black) are then added to the toluene solution under high shear. Sonication may be added to achieve a smooth paste, which is then coated onto the Cu foil. The dry composition of the electrode is the same as in the comparative example, namely, approximately 94% active anode material, approximately 2% conductive additive, and approximately 4% binder.

[0114] [ Example 11 This is similar to Comparative Example 1, except that SBR is replaced with IR401.

[0115] [Table 1]

[0116] Electrode fabrication: The as-prepared electrode paste is coated onto copper foil (anode paste) or aluminum foil (cathode paste). The coating can be performed using a knife coating method, with a coating thickness of approximately 300 microns. The coating is then calendered to a porosity of approximately 35%.

[0117] Coin Cell Manufacturing: Many battery cells (coil cell type) are manufactured. For each cell, a 1.47 cm diameter disc is punched out from a laminate for use in the coin cell assembly as the working electrode. Lithium foil is used to make the counter electrode and is cut into a 1.5 cm diameter disc. A 2 cm diameter porous polyethylene separator is placed on top of the working electrode. The cell is then dried under vacuum at approximately 80°C to 120°C for approximately 24 hours, and the electrolyte, which is 1 M LiPF6 in EC:DEC (ethylene carbonate:ethyl methyl carbonate) in a weight ratio of 1:1, is injected into the cell. The battery cell is ready for testing.

[0118] Coin Cell Testing: Battery cells are placed in a test chamber at 25°C. During testing, voltage and current data over time are recorded over numerous charge and discharge cycles. From this data, cell capacity, resistance, Coulomb efficiency, and other performance data are derived. Unless otherwise specified, four cells are used in each test, and the results are the average of the four tests. Unless otherwise specified, the charge and discharge rates are C / 10. Table 2 shows the delithiation capabilities of electrodes with different types of binders.

[0119] [Table 2]

[0120] The terms “comprising” and “including” have been used herein to describe various aspects, but the terms “essentially consisting of” and “consisting of” may be used instead of “comprising” and “including” to provide more specific aspects of this disclosure, and are also disclosed.

Claims

1. A binder composition for use in rechargeable batteries, At least 20% by weight of a styrene-based block copolymer having one of the following structures: linear, radial, or branched, i) Monovinyl aromatic block, ii) A cyclic conjugated diene block and at least one conjugated diene block, iii) Selectively select coupling agent residues Includes, Styrene-based block copolymers having residual unsaturation of 0.5 to 25 meq / g and a glass transition temperature (Tg) in the range of 30 to 90°C, as measured by dynamic mechanical analysis (DMA) using ASTM 4065; A tackifier selected from hydrocarbon resins, alkyd resins, rosin resins, rosin esters, and combinations thereof, in an amount of 70% by weight or less; A plasticizer selected from vegetable oils, mineral oils, process oils, phthalates, and mixtures thereof, in an amount of 40% by weight or less. A binder composition containing [the specified ingredient].

2. The binder composition according to claim 1, wherein the styrene-based block copolymer is not hydrogenated.

3. The binder composition according to claim 1, wherein the styrene-based block copolymer has a polystyrene content of less than 40% by weight.

4. The binder composition according to claim 1, wherein the monovinyl aromatic is selected from the group consisting of styrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 2,4-dimethylstyrene, alpha-methylstyrene, vinylnaphthalene, vinyltoluene, vinylxylene, adamantylstyrene, vinylanthracene, vinylbiphenyl, 1,1-diphenylethylene, and mixtures thereof.

5. The binder composition according to claim 1, wherein the cyclic conjugated diene is selected from the group consisting of 1,3-cyclohexadiene, benzoflubene, and combinations thereof.

6. The binder composition according to claim 1, wherein the conjugated diene polymer is selected from the group consisting of butadiene, isoprene, and mixtures thereof.

7. Styrene-based block copolymers Non-hydrogenated block polymers having a general structure A-I-B-I-A or (A-I-B)n-X [wherein each A block is independently a vinyl aromatic compound, each I block is mainly isoprene, each B is mainly butadiene, X is a coupling agent residue, and n is an integer of 2 or more]; Non-hydrogenated radial block copolymer having a general structure (A-B)n-X [wherein n is in the range of 3 to 4, X is a coupling agent residue, block A is a vinyl aromatic polymer block, and block B is a conjugated diene polymer block]; Styrene-based block copolymers having a general structure of A-B-A or A-B-X-(B-A)n [wherein each A is a polymerized monoalkenylarene, each B is a polymerized conjugated diene, X represents a coupling agent residue, and n is an integer of 2 or more, representing the average number of arms in the radial structure]; Styrene-based block copolymers having the general structure of A-B, A-B-A, (A-B)n(A-B-A)n(A-B-A)nX, (A-B)nX, A1-B1-A2-B2 [wherein each A, A1 and A2 block is a monoalkenylarene polymer block, each B and B1 block is a controlled distribution copolymer block of at least one conjugated diene and at least one monoalkenylarene, each B2 block is selected from the group consisting of (i) a controlled distribution copolymer block of at least one conjugated diene and at least one monoalkenylarene, (ii) a homopolymer block of a conjugated diene, and (iii) a copolymer block of two or more different conjugated dienes, where X is a coupling agent residue and n is an integer from 2 to 30; or mixtures thereof; The styrene-based block copolymer is in the form of an aqueous dispersion containing an isoprene rubber latex, having two or more polystyrene blocks containing less than 5% by weight of copolymerizable monomers based on the weight of the polystyrene block, and at least one block of polyisoprene containing less than 5% by weight of copolymerizable monomers based on the weight of the block polymerization conjugated diene; One or more cyclic dienes selected from the group consisting of 1,3-cyclohexadiene (CHD), cyclopentadiene (CPD), 1,3-cycloheptadiene, 4,5,6,7-tetrahydroindene, norbornadiene (NBD) and combinations thereof; and copolymers formed by cationic polymerization of comonomers selected from the group consisting of monoterpenes, branched styrene and combinations thereof; and A star-shaped branched copolymer comprising: polymer unit (i), wherein each polymer arm is a polymerization unit (i) derived from a first vinyl aromatic monomer containing a radical reactive group, and more than 10 mol% to 100 mol% of polymerization unit (i) is unhydrogenated; and polymerization unit (ii), optionally comprising (iiiA) hydrogenated and unhydrogenated forms of polymerization unit (ii) derived from a high Tg monomer having a Tg of 300°C or less, and (iiiB) a hydrogenated form of polymerization unit (i) or a hydrogenated form of polymer styrene unit; and polymerization unit (iii), optionally comprising (iiiA) a hydrogenated form of polymerization unit derived from one or more acyclic conjugated dienes and (iiiB) polymerization units derived from one or more second vinyl aromatic monomers, a star-shaped branched copolymer. A binder composition according to any one of claims 1 to 6, selected from the group.

8. The binder composition according to any one of claims 1 to 6, wherein the styrene-based block copolymer is functionalized with a functional group selected from the group consisting of maleation, epoxidation, silanation, carboxylic acid / salt, quaternary ammonium salt, and sulfonation.

9. The binder composition according to claim 8, wherein the functional group is formed by functionalization after polymerization, polymerization of monomers having a functional group, or a combination thereof.

10. The binder composition according to any one of claims 1 to 6, wherein the styrene-based block copolymer is in various forms, including but not limited to powder, pellets, crumbs, solution, suspension, aqueous dispersion, or latex.

11. The binder composition according to claim 10, wherein the aqueous dispersion contains a surfactant.

12. The binder composition according to any one of claims 1 to 6, wherein the styrene-based block copolymer may be blended with other polymers, resins and / or tackifiers / adhesion promoters, and the blended material may include, but is not limited to, a blend of polyamides, terpene / phenol resins and rosin esters, which may be in latex form.

13. The binder composition according to any one of claims 1 to 6, further comprising at least 85% by weight of at least one electrode active material selected from graphite, carbon black, Li, Al, Si, Si alloy, Si compound, or Si composite material.

14. A binder composition according to any one of claims 1 to 6, wherein the styrene-based block copolymer has a particle size of 0.05 to 20.0 μm.

15. Styrene-based block copolymers Over 400% elongation at the break, Glass transition temperature (Tg) of 40-90°C, 2.2-3 Insulation constant (Dk) and Dissipation coefficient (Df) between 0.001 and 0.01 A binder composition according to any one of claims 1 to 6, having one or more of the above.

16. electrode active material, Fillers and Binder according to any one of claims 1 to 6 An electrode composition comprising, An electrode active material selected from Si, Si alloys, Si compounds, Si composites, carbon black, and graphite accounts for at least 85% by weight based on the total weight of the electrode composition. The binder is a trace component, accounting for less than 15% by weight based on the total weight of the electrode composition. Electrode composition.

17. The electrode composition according to claim 16, wherein the binder is selected from at least one of isoprene rubber (IR), silicone-containing block copolymer, electronically conductive block copolymer, and ionically conductive block copolymer.

18. A method for producing the electrode composition described in claim 16 by fiber spinning, wherein the fiber spinning may be melt spinning or solution spinning.

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