Polyacrylate electrolyte for lithium ion circulating battery pack and battery pack comprising same

Abstract

The invention relates to a polyacrylate electrolyte for a battery for circulating lithium ions and a battery comprising the same. An electrolyte of a battery for circulating lithium ions comprises a polyacrylate and a liquid electrolyte immobilized in the polyacrylate. The polyacrylate comprises acrylate monomers covalently bonded to each other. The liquid electrolyte includes a lithium salt in an organic solvent.

Description

[0001] Government sponsorship

[0002] This invention was made with government support under Award No. DE-EE0008230, awarded by the U.S. Department of Energy. The government has certain rights in this invention. Technical field

[0003] The present disclosure relates to an electrolyte for a battery pack for cycling lithium ions, and more particularly to an electrolyte comprising a polymer matrix and a liquid electrolyte immobilized in the polymer matrix. Background art

[0004] The information provided in this section is intended to present generally the background of the present disclosure. To the extent that the work of the presently named inventors described in this section and aspects that may not constitute prior art at the time of filing are not expressly or implicitly admitted to be prior art against the present disclosure.

[0005] Battery packs for cycling lithium ions typically include a positive electrode, a negative electrode spaced apart from the positive electrode, and an ion-conductive electrolyte that provides a medium for the conduction of lithium ions between the positive and negative electrodes during discharge and charging of the battery pack. The electrolyte can be formulated to exhibit certain desired properties, including high ionic conductivity, good thermal stability, a wide electrochemical stability window, the ability to form a stable ion-conductive solid electrolyte interface on the surface of the positive and / or negative electrodes, and chemical compatibility with other components of the battery pack. Summary of the invention

[0006] According to one or more embodiments of the present disclosure, an electrolyte for a battery pack for cycling lithium ions comprises a polyacrylate and a liquid electrolyte immobilized in the polyacrylate. The polyacrylate comprises acrylate monomers covalently bonded to each other. The liquid electrolyte comprises a lithium salt in an organic solvent.

[0007] The acrylate monomers can include acrylates, N-alkyl acrylates, N-cycloalkyl acrylates, dialkyl acrylates, hydroxyalkyl acrylates, N-aryl acrylates, methacrylates, N-alkyl methacrylates, N-cycloalkyl methacrylates, dialkyl methacrylates, dialkylaminoalkyl methacrylates, hydroxyalkyl methacrylates, N-aryl methacrylates, or combinations thereof.

[0008] At least one of the acrylate monomers can comprise a substituent selected from silyl, siloxy, alkoxysilyl, sulfo, and phosphate ester.

[0009] The polyacrylate may further comprise a polyacrylate crosslinking agent. In this case, the acrylate monomer and the polyacrylate crosslinking agent may be covalently bonded to each other to form a three-dimensional network of interconnected polyacrylate chains.

[0010] The polyacrylate crosslinking agent may include ethylene glycol poly(meth)acrylate, propylene glycol poly(meth)acrylate, glycerol poly(meth)acrylate, trimethylolpropane poly(meth)acrylate, pentaerythritol poly(meth)acrylate, or a combination thereof.

[0011] The polyacrylate may further comprise an acrylonitrile monomer. In this case, the acrylate monomer and the acrylonitrile monomer may be covalently bonded to each other.

[0012] The polyacrylate may include a polymer having the formula (1):

[0013]

[0014] wherein: m is an integer greater than 1; n is zero or an integer; p is zero or an integer; q is zero or 1; R 1 、R 3 、R 4 and R 5 are each independently H, a hydroxyl group, a hydrocarbon group, a heterohydrocarbon group, a silyl group, a siloxy group, an alkoxysilyl group, a sulfo group, a phosphate ester, or an acrylate moiety; R 2 is a divalent hydrocarbon group or heterohydrocarbon group; and L is a divalent hydrocarbon group, heterohydrocarbon group, or acrylate-containing moiety, and the sum of m + n + p is greater than or equal to 100 and less than or equal to 200,000.

[0015] In the polymer having the formula (1), L may be a divalent acrylate-containing moiety having the formula (2):

[0016]

[0017] wherein: a, b, c, and d are each independently zero or 1; R 6 and R 7 are each independently a divalent hydrocarbon group or heterohydrocarbon group; R 8 and R 9 are each independently a divalent hydrocarbon group, heterohydrocarbon group, diorganosulfate, or diorganophosphate; and R 10 and R 11 are each independently H, a hydroxyl group, a hydrocarbon group, a heterohydrocarbon group, a silyl group, a siloxy group, an alkoxysilyl group, a sulfo group, a phosphate ester, or an acrylate moiety.

[0018] In the divalent acrylate-containing moiety having the formula (2), R 10 or R 11At least one of them may be an acrylate moiety.

[0019] The organic solvent may include an ether-based solvent.

[0020] The lithium salt may include lithium hexafluorophosphate (LiPF6), lithium bis(trifluoromethane)sulfonimide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), or a combination thereof.

[0021] The electrolyte may further contain an additive including lithium nitrate (LiNO3).

[0022] According to one or more embodiments of the present disclosure, a battery pack for cycling lithium ions includes a negative electrode, a positive electrode spaced apart from the negative electrode by a gap, and a polymer electrolyte disposed within the gap between the negative electrode and the positive electrode. The negative electrode contains an electroactive negative electrode material. The positive electrode contains an electroactive positive electrode material. The polymer electrolyte contains polyacrylate and a liquid electrolyte immobilized in the polyacrylate. The polyacrylate contains acrylate monomers covalently bonded to each other. The liquid electrolyte contains an ether-based organic solvent, a lithium salt, and an additive. The lithium salt includes lithium hexafluorophosphate (LiPF6), lithium bis(trifluoromethane)sulfonimide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), or a combination thereof. The additive includes lithium nitrate (LiNO3).

[0023] The acrylate monomer may include acrylate, N-alkyl acrylate, N-cycloalkyl acrylate, dialkyl acrylate, hydroxyalkyl acrylate, N-aryl acrylate, methacrylate, N-alkyl methacrylate, N-cycloalkyl methacrylate, dialkyl methacrylate, dialkylaminoalkyl methacrylate, hydroxyalkyl methacrylate, N-aryl methacrylate, or a combination thereof.

[0024] At least one of the acrylate monomers may contain a substituent selected from silyl, silyloxy, alkoxysilyl, sulfo, and phosphate ester.

[0025] The polyacrylate may further contain a polyacrylate crosslinking agent. In this case, the acrylate monomer and the polyacrylate crosslinking agent may be covalently bonded to each other to form a three-dimensional network of interconnected polyacrylate chains.

[0026] The polyacrylate may further contain an acrylonitrile monomer. In this case, the acrylate monomer and the acrylonitrile monomer may be covalently bonded to each other.

[0027] The polyacrylate may contain a polymer having the formula (1):

[0028]

[0029] Wherein: m is an integer greater than 1; n is zero or an integer; p is zero or an integer; q is zero or 1; R 1 、R 3 、R 4 and R 5 are each independently H, a hydroxyl group, a hydrocarbon group, a hetero-hydrocarbon group, a silyl group, a siloxy group, an alkoxysilyl group, a sulfo group, a phosphate ester or an acrylate moiety; R 2 is a divalent hydrocarbon group or hetero-hydrocarbon group; and L is a divalent hydrocarbon group, hetero-hydrocarbon group or acrylate-containing moiety, and

[0030] the sum of m + n + p is greater than or equal to 100 and less than or equal to 200,000.

[0031] The battery pack according to aspect 17, wherein L is a divalent acrylate-containing moiety having formula (2):

[0032]

[0033] Wherein: a, b, c and d are each independently zero or 1; R 6 and R 7 are each independently a divalent hydrocarbon group or hetero-hydrocarbon group; R 8 and R 9 are each independently a divalent hydrocarbon group, hetero-hydrocarbon group, diorganosulfate or diorganophosphate; and R 10 and R 11 are each independently H, a hydroxyl group, a hydrocarbon group, a hetero-hydrocarbon group, a silyl group, a siloxy group, an alkoxysilyl group, a sulfo group, a phosphate ester or an acrylate moiety, and wherein at least one of R 10 or R 11 is an acrylate moiety.

[0034] The electroactive positive electrode material may include a sulfur-based material. The electroactive negative electrode material may include pore-free lithium.

[0035] According to one or more embodiments of the present disclosure, a method of manufacturing a battery pack for cycling lithium ions includes the step of assembling a stack including a negative electrode and a positive electrode, wherein the negative electrode and the positive electrode are spaced apart from each other by a gap. The stack is infiltrated with an electrolyte precursor comprising an acrylate monomer, a radical initiator and a liquid electrolyte. The radical polymerization of the acrylate monomer is initiated such that the acrylate monomers covalently bond to each other to form a polyacrylate.

[0036] Further applicable fields of the present disclosure will become apparent from the detailed description, the claims and the drawings. The detailed description and the specific examples are only intended for illustration and are not intended to limit the scope of the present disclosure. Description of the Drawings

[0037] The present disclosure will be more fully understood from the detailed description and the accompanying drawings, in which:

[0038] Figure 1 is a schematic perspective view of a motor vehicle powered by a battery pack including a plurality of battery pack modules.

[0039] Figure 2 is Figure 1 a schematic cross-sectional view of a part of one of the battery pack modules, the battery pack module including a plurality of electrochemical cells or battery packs that cycle lithium ions.

[0040] Figure 3 is a schematic cross-sectional view of a battery pack that cycles lithium ions, the battery pack including a positive electrode, a negative electrode, and a polymer electrolyte disposed between the positive electrode and the negative electrode.

[0041] In the drawings, reference numerals may be reused to identify like and / or identical elements. Detailed Description

[0042] Definitions

[0043] "Hydrocarbyl" means a functional group containing only hydrogen and carbon atoms, including branched or unbranched, saturated or unsaturated, cyclic, polycyclic or acyclic groups. A hydrocarbyl group is formed by removing at least one hydrogen atom from a hydrocarbon molecule. Depending on the number of hydrogen atoms removed, a hydrocarbyl group can be monovalent (formed by removing one hydrogen atom, also referred to as a hydrocarbyl group), divalent (formed by removing two hydrogen atoms, also referred to as a hydrocarbylene group), and so on. Examples of monovalent hydrocarbyl groups include alkyl, cycloalkyl, alkenyl, cycloalkenyl, aryl, and alkynyl. Examples of divalent hydrocarbyl groups include alkylene, cycloalkylene, alkenylene, alkynylene, and arylene.

[0044] "Heterohydrocarbyl" means a hydrocarbyl group in which at least one carbon atom is replaced by a heteroatom such as nitrogen, oxygen, sulfur, phosphorus, boron, or silicon. Examples of heterohydrocarbyl groups include alkoxy, aryloxy, -CH2OCH3, and oxyalkylene (e.g., -CH2CH2O-).

[0045] "Acrylate" means a compound, moiety, or functional group having the formula R'OCOCR”=CH2, where R' and R” are each independently H, a hydrocarbyl group, or a heterohydrocarbyl group. The term "(meth)acrylate" means a methacrylate, an acrylate, or a combination thereof.

[0046] "Substituted" means a compound, moiety, or functional group in which at least one hydrogen atom bonded to a carbon atom is replaced by a substituent that is a functional group. Examples of substituents include hydroxy (-OH), heterohydrocarbyl, phosphate, amino, halogen, silyl, and sulfo groups.

[0047] "Silyl" refers to a functional group having the formula -SiR'R"R''', where R', R", and R''' are each independently H, a hydrocarbon group, or a hetero-hydrocarbon group.

[0048] "Siloxy" refers to a functional group having the formula -OSiR'R"R''', where R', R", and R''' are each independently H, a hydrocarbon group, or a hetero-hydrocarbon group.

[0049] "Alkoxysilyl" refers to a functional group having the formula -Si(OR)3, where R is H, a hydrocarbon group, a hetero-hydrocarbon group, or -Si(OR)3.

[0050] "Sulfo" refers to a functional group having the formula -SO3R, where R is H, a hydrocarbon group, or a hetero-hydrocarbon group.

[0051] "Di-organic sulfate" refers to a functional group having the formula -R'O-SO2-OR"-, where R' and R" are each independently a divalent hydrocarbon group or a divalent hetero-hydrocarbon group.

[0052] "Phosphate" refers to a functional group having the formula -OPO(OR)2, where R is H, a hydrocarbon group, or a hetero-hydrocarbon group.

[0053] "Di-organic phosphate" refers to a functional group having the formula -R'OPO(OR")OR''', where R" is H, a hydrocarbon group, or a hetero-hydrocarbon group and R' and R''' are each independently a divalent hydrocarbon group or a divalent hetero-hydrocarbon group.

[0054] The expression "at least one of A, B, and C" should be construed to mean the logical (A OR B OR C) using non-exclusive logical OR and should not be construed to mean "at least one A, at least one B, and at least one C".

[0055] The term "and / or" includes combinations of one or more of the associated listed items.

[0056] Unless the context clearly dictates otherwise, the singular forms "a", "an", and "the" are intended to include the plural forms as well.

[0057] The terms "comprising", "including", "containing", and "having" are inclusive and thus specify the presence of the recited features, elements, compositions, steps, integers, operations, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Although the open-ended terms "comprising", "including", "containing", and "having" will be understood to be non-limiting terms for describing and claiming the various embodiments set forth herein, in some instances, these terms may alternatively be understood to be more restrictive and limiting terms, such as "consisting of" or "consisting essentially of". Accordingly, for any given embodiment that recites a composition, material, component, element, ingredient, feature, integer, operation, and / or process step, the present disclosure specifically includes embodiments consisting of or consisting essentially of such recited composition, material, component, element, ingredient, feature, integer, operation, and / or process step.

[0058] The terms "composition" and "material" are used interchangeably to generally refer to a substance that includes at least a preferred chemical component, element, or compound, but it may also include additional elements, compounds, or substances, including trace impurities (i.e., amounts less than or equal to 0.1%). A "composition or material based on X" generally refers to a composition or material in which "X" is the single largest component of the composition or material by weight percentage (%). This can include compositions or materials having greater than 50 wt% X, as well as compositions or materials having less than 50 wt% X, provided that X is the single largest component of the composition or material based on its total weight. When a composition or material is said to be "substantially free of" a substance, then the composition or material may contain less than 5 wt%, optionally less than 3 wt%, optionally less than 1 wt%, or optionally less than 0.1 wt% of the substance.

[0059] The term "metal" can refer to a pure elemental metal or an elemental metal and one or more other metal or non-metal elements. The term "elemental metal" refers to the relevant metal in its purest form and does not contain any other elements, except for traces, i.e., as impurities.

[0060] Embodiment

[0061] The presently disclosed polymer electrolytes can be used in battery packs that cycle lithium ions to help reduce the interfacial resistance between the electrolyte and the positive and negative electrodes, which can help improve the electrochemical performance of the battery pack. When used in a battery pack that includes a sulfur-based electroactive positive electrode material, the polymer electrolyte can help prevent or inhibit polysulfide dissolution and shuttling between the positive and negative electrodes, which can help improve the cycle life and Coulombic efficiency of the battery pack. Additionally, when used in a battery pack that includes a non-porous lithium metal negative electrode, the polymer electrolyte can help promote uniform deposition of metallic lithium, thereby avoiding the nucleation and growth of undesirable lithium dendrites. The presently disclosed polymer electrolytes comprise a polyacrylate and a liquid electrolyte immobilized in the polyacrylate.

[0062] Figure 1 Depicted is a motor vehicle 2 powered by an electric motor 4 that draws electrical power from a battery pack 6 including one or more battery pack modules 8. The battery pack modules 8 can be electrically coupled together in series and / or parallel arrangements to meet the desired capacity and power requirements of the electric motor 4. The vehicle 2 can be an all-electric vehicle and can be powered only by the electric motor 4, or the vehicle 2 can be a hybrid electric vehicle and can be powered by the electric motor 4 and an internal combustion engine (not shown).

[0063] As Figure 2 shown, each battery pack module 8 includes one or more electrochemical cells or battery packs 10 that cycle lithium ions. In practice, the battery packs 10 in the battery pack module 8 are typically assembled as a stack of layers including a negative electrode layer 12, a negative electrode current collector 13, a positive electrode layer 14, a positive electrode current collector 15, and a separator layer 16. Each battery pack 10 is defined by a negative electrode layer 12 and a positive electrode layer 14 spaced apart from each other by the separator layer 16. In practice, the separator layer 16 can be impregnated with an electrolyte that provides a medium for the conduction of lithium ions between the negative electrode layer 12 and the positive electrode layer 14, or the separator layer 16 itself can act as the electrolyte. The negative electrode layer 12 is disposed on the negative electrode current collector 13 and is in electrical communication with the negative electrode current collector 13, and the positive electrode layer 14 is disposed on the positive electrode current collector 15 and is in electrical communication with the positive electrode current collector 15. As Figure 2 shown, for efficiency, the layers can be stacked such that some of the negative electrode current collectors 13 and some of the positive electrode current collectors 15 are double-sided and include a negative electrode layer 12 or a positive electrode layer 14, respectively, on both sides thereof. In this arrangement, adjacent negative electrode layers 12 and positive electrode layers 14 share a single negative electrode current collector 13 or positive electrode current collector 15, respectively.

[0064] Figure 3Depicts an electrochemical cell or battery pack 20 that cycles lithium ions. The battery pack 20 can generate an electric current during discharge, which can be used to power a load device (e.g., an electric motor 4), and can be charged by connecting to a power source. Similar to Figure 1 and Figure 2 the battery pack 10 shown in in all aspects, the battery pack 20 can be used to power the electric motor 4 of a motor vehicle 2. Additionally or alternatively, the battery pack 20 can be used in other transportation applications (e.g., motorcycles, boats, tractors, buses, motorcycles, mobile homes, campers, tanks, and aircraft), and can be used to provide power to fixed and / or mobile electronic devices, components, and apparatuses used in a variety of other industries and applications, including industrial, residential, and commercial buildings, consumer goods, industrial equipment and machinery, agricultural or farming equipment, and heavy machinery, by way of non-limiting examples.

[0065] The battery pack 20 includes a negative electrode 22, a positive electrode 24, and a polymer electrolyte 28 disposed between an opposing surface 38 of the negative electrode 22 and an opposing surface 40 of the positive electrode 24. The negative electrode 22 is disposed on a major surface of a negative electrode current collector 30, and the positive electrode 24 is disposed on a major surface of a positive electrode current collector 32. In practice, the negative electrode current collector 30 and the positive electrode current collector 32 are electrically coupled to a power source or load 34 (e.g., an electric motor 4) via an external circuit 36. The negative electrode 22 and the positive electrode 24 are formulated such that an electrochemical potential difference is established between the negative electrode 22 and the positive electrode 24 when the battery pack 20 is at least partially charged. During discharge of the battery pack 20, the electrochemical potential established between the negative electrode 22 and the positive electrode 24 drives a spontaneous reduction and oxidation (redox) reaction within the battery pack 20 and releases lithium ions and electrons from the negative electrode 22. The released lithium ions travel from the negative electrode 22 to the positive electrode 24 through the polymer electrolyte 28, while the electrons travel from the negative electrode 22 to the positive electrode 24 through the external circuit 36, which generates an electric current. After the negative electrode 22 has been partially or completely depleted of lithium, the battery pack 20 can be charged by connecting the negative electrode 22 and the positive electrode 24 to a power source 34, which drives a non-spontaneous redox reaction within the battery pack 20 and releases lithium ions and electrons from the positive electrode 24. The repeated discharge and charge of the battery pack 20 can be referred to herein as "cycling", where one complete charge event followed by one complete discharge event is considered one full cycle.

[0066] The positive electrode 24 is configured to store and release lithium ions during discharge and charge of the battery pack 20. The positive electrode 24 can be in the form of a continuous porous layer disposed on a major surface of the positive electrode current collector 32 and having open pores extending therethrough. The positive electrode 24 includes an electrochemically active (electroactive) material (electroactive positive electrode material), a polymer binder, and optionally a conductive material. In various aspects, the electroactive material of the positive electrode 24 can be particulate material, and the particles of the electroactive material of the positive electrode 24 can be mixed with the polymer binder and optionally the conductive material.

[0067] The electroactive material of the positive electrode 24 can store and release lithium ions by reversible redox reaction with lithium at a higher electrochemical potential than the electroactive material of the negative electrode 22, such that there is an electrochemical potential difference between the negative electrode 22 and the positive electrode 24. The electroactive material of the positive electrode 24 can include materials capable of lithium intercalation and deintercalation or materials capable of conversion reaction with lithium. In embodiments in which the electroactive material of the positive electrode 24 includes an intercalation host material capable of reversible insertion or intercalation of lithium ions, the electroactive material of the positive electrode 24 can include a lithium transition metal oxide. For example, the electroactive material of the positive electrode 24 can include layered lithium transition metal oxides represented by the formula LiMeO2 and / or Li2MeO3, layered lithium-rich transition metal oxides represented by the formula Li 1+x Me 1-x O2 (where 0 < x ≤ 0.33), olivine-type lithium transition metal oxides represented by the formula LiMePO4, monoclinic lithium transition metal oxides represented by the formula Li3Me2(PO4)3, spinel-type lithium transition metal oxides represented by the formula LiMe2O4, tavorite represented by one or both of the formulas LiMeSO4F or LiMePO4F, or combinations thereof, where Me is a transition metal (e.g., Co, Ni, Mn, Fe, Al, V, or combinations thereof). In embodiments in which the electroactive material of the positive electrode 24 includes a conversion material, the electroactive material of the positive electrode 24 can include sulfur, selenium, tellurium, iodine, halides (e.g., fluorides or chlorides), sulfides, selenides, tellurides, iodides, phosphides, nitrides, oxides, oxysulfides, oxyfluorides, sulfur-fluorides, sulfur-oxyfluorides, or lithium and / or metal compounds thereof (e.g., compounds of iron, manganese, nickel, copper, and / or cobalt).

[0068] In an embodiment, the electroactive material of the positive electrode 24 may include a sulfur-based material. In an embodiment, the electroactive material of the positive electrode 24 may include a composite material that includes sulfur and / or a sulfur-based material distributed within a conductive matrix material. Examples of the conductive matrix material include carbon-based materials, metal compounds, conductive polymers, and combinations thereof. Examples of the conductive carbon-based matrix materials include graphene, reduced graphene oxide, carbon nanotubes (CNT), hierarchical porous carbon, hollow structured carbon, and combinations thereof. Examples of the metal compound matrix materials include manganese oxide (MnO2), titanium oxide (TiO2), iron oxide (Fe2O3), vanadium oxide (V2O5), cobalt sulfide (CoS2 and / or Co9S8), titanium sulfide (TiS), titanium nitride (TiN), titanium carbide (Ti2C), lithium sulfide (Li2S), and combinations thereof. Examples of the conductive polymer matrix materials include polyacrylonitrile (PAN), polypyrrole, polythiophene, poly(3,4-ethylenedioxythiophene) (PEDOT), and combinations thereof. In an embodiment, the electroactive material of the positive electrode 24 may include sulfurized polyacrylonitrile (SPAN).

[0069] The electroactive material of the positive electrode 24 may constitute greater than or equal to about 50 wt%, optionally greater than or equal to about 60 wt%, or optionally greater than or equal to about 70 wt%, and less than or equal to about 95 wt%, optionally less than or equal to about 90 wt%, or optionally less than or equal to about 80 wt% of the positive electrode 24.

[0070] The polymeric binder is electrochemically inert and may be included in the positive electrode 24 to provide structural integrity to the positive electrode 24 and / or assist in adhering the positive electrode 24 to the main surface of the positive electrode current collector 32. Examples of the polymeric binder include polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), ethylene propylene diene monomer (EPDM) rubber, styrene butadiene rubber (SBR), carboxymethyl cellulose (CMC), nitrile butadiene rubber (NBR), styrene butadiene rubber (SBR), styrene-ethylene-butene-styrene copolymer (SEBS), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyacrylate, alginate, polyacrylic acid, and combinations thereof. The polymeric binder may constitute greater than or equal to about 1 wt%, or optionally greater than or equal to about 5 wt%, and less than or equal to about 10 wt% of the positive electrode 24.

[0071] The optional conductive material is electrochemically inert and can be included in the positive electrode 24 to provide sufficient conductivity to the positive electrode 24 to support the penetration of electrons therethrough. Examples of the conductive material include carbon-based materials, metals (such as nickel), and / or conductive polymers. Examples of the conductive carbon-based materials include carbon black (CB) (e.g., acetylene black), graphite, graphene (e.g., graphene nanosheets, GNP), graphene oxide, carbon nanotubes (CNT), and / or carbon fibers (e.g., carbon nanofibers). Examples of the conductive polymers include polyaniline, polythiophene, polyacetylene, and / or polypyrrole. When included in the positive electrode 24, the optional conductive material can constitute greater than 0 wt% of the positive electrode 24, optionally greater than or equal to about 1 wt%, or optionally greater than or equal to about 5 wt%, and less than or equal to about 10 wt%.

[0072] The negative electrode 22 is configured to store and release lithium ions to facilitate charging and discharging of the battery pack 20, respectively. The negative electrode 22 can be in the form of a continuous material layer disposed on the major surface of the negative electrode current collector 30. The negative electrode 22 includes an electrochemically active (electroactive) material (electroactive negative electrode material) that can store and release lithium ions through reversible redox reactions with lithium during charging and discharging of the battery pack 20. Examples of the electroactive negative electrode materials include lithium, lithium-based materials (e.g., alloys of lithium with silicon, aluminum, indium, and / or tin), carbon-based materials (e.g., graphite, activated carbon, carbon black, hard carbon, soft carbon, and / or graphene), silicon, silicon-based materials (e.g., alloys of silicon with lithium, tin, iron, aluminum, and / or cobalt), silicon oxides, silicon oxide-based materials (e.g., lithium silicon oxide), tin oxides, aluminum, indium, zinc, germanium, titanium oxides, lithium titanate, and combinations thereof.

[0073] In some embodiments, the negative electrode 22 can be porous and can have open pores extending therethrough. In such a case, the electroactive material of the negative electrode 22 can be particulate material, and the particles of the electroactive material of the negative electrode 22 can be mixed with a polymer binder and an optional conductive material. In such a case, the electroactive material of the negative electrode 22 can constitute greater than or equal to about 50 wt% of the negative electrode 22, optionally greater than or equal to about 60 wt%, or optionally greater than or equal to about 70 wt%, and less than or equal to about 95 wt%, optionally less than or equal to about 90 wt%, or optionally less than or equal to about 80 wt%. The same polymer binder and / or conductive material as disclosed above for the positive electrode 24 can be used in the negative electrode 22 in substantially the same amounts.

[0074] In other embodiments, the electroactive material of the negative electrode 22 can consist of lithium, and the negative electrode 22 can be in the form of a non-porous metal film or foil, such as a lithium metal film or lithium metal foil. In such cases, the negative electrode 22 can contain greater than 97 weight percent lithium, or optionally greater than 99 weight percent lithium. In embodiments where the electroactive material of the negative electrode 22 consists of lithium, the negative electrode 22 can be substantially free of elements or compounds that undergo a reversible redox reaction with lithium during operation of the battery pack 20. Additionally, in such embodiments, the negative electrode 22 can be substantially free of polymer binders.

[0075] The polymer electrolyte 28 is ionically conductive and is formulated to provide a medium for the conduction of lithium ions between the negative electrode 22 and the positive electrode 24. The polymer electrolyte 28 physically separates and electrically isolates the negative electrode 22 and the positive electrode 24 from each other while allowing lithium ions to pass through it. The polymer electrolyte 28 can be sandwiched between the negative electrode 22 and the positive electrode 24 and can be in direct physical contact with the opposing facing surfaces 38, 40 of the negative electrode 22 and the positive electrode 24. In embodiments where the negative electrode 22 and / or the positive electrode 24 are porous, the polymer electrolyte 28 can be at least partially immersed in their open pores. The polymer electrolyte 28 comprises a polyacrylate, a liquid electrolyte immobilized in the polyacrylate, and optionally a support structure. The thickness of the polymer electrolyte 28 can be greater than or equal to 5 micrometers (μm), optionally greater than or equal to 10 μm, or optionally greater than or equal to 20 μm, and less than or equal to 500 μm, optionally less than or equal to 200 μm, or optionally less than or equal to 50 μm.

[0076] The polyacrylate is formulated to provide flexibility to the polymer electrolyte 28 and the ability to establish a strong interfacial contact with the facing surface 38 of the negative electrode 22 and the facing surface 40 of the positive electrode 24, which can help reduce the interfacial resistance between the polymer electrolyte 28 and the negative electrode 22 and the positive electrode 24. Additionally, in embodiments where the electroactive material of the positive electrode 24 includes a sulfur-based material, the polyacrylate can help prevent polysulfides generated in the positive electrode 24 from diffusing through the polymer electrolyte 28 and reacting undesirably with the lithium metal in the negative electrode 22 to form insoluble polysulfides, and thereby reduce the cycle life and coulombic efficiency of the battery pack 20 (a phenomenon known as polysulfide dissolution and shuttling). Further, in embodiments where the negative electrode 22 consists of non-porous lithium, the polyacrylate can help provide low ionic concentration polarization at the interface between the negative electrode 22 and the polymer electrolyte 28, which can help promote uniform deposition of metallic lithium on the facing surface 38 of the negative electrode 22, thereby hindering the nucleation and growth of undesirable lithium dendrites. The polyacrylate can constitute greater than or equal to 1 wt%, optionally greater than or equal to 5 wt%, and less than or equal to 30 wt%, optionally less than or equal to 20 wt%, or optionally less than or equal to 10 wt% of the polymer electrolyte 28.

[0077] The polyacrylate comprises acrylate monomers, an optional polyacrylate crosslinker, and an optional acrylonitrile monomer. In the polyacrylate, the acrylate monomers, the optional polyacrylate crosslinker, and the optional acrylonitrile monomer are covalently bonded to each other. In embodiments, the polyacrylate can be a homopolymer or copolymer having the formula (1):

[0078]

[0079] wherein X is an acrylate monomer; Y is a polyacrylate crosslinker; Z is an acrylonitrile monomer; m is an integer greater than 1; n is zero or an integer; p is zero or an integer; q is zero or 1; R 1 、R 3 、R 4 and R 5 are each independently H, a hydroxyl group, a hydrocarbyl group, a heterohydrocarbyl group, a silyl group, a silyloxy group, an alkoxysilyl group, a sulfo group, a phosphate ester, or an acrylate moiety; R 2 is a divalent hydrocarbyl or heterohydrocarbyl group; and L is a divalent hydrocarbyl, heterohydrocarbyl, or acrylate-containing moiety. In embodiments, the sum of m + n + p can be greater than or equal to 100 and less than or equal to 200,000. In embodiments, L is a divalent acrylate-containing moiety having the formula (2):

[0080]

[0081] wherein a, b, c and d are each independently zero or 1; when present, R 6 and R 7 are each independently a divalent hydrocarbon or heterohydrocarbon group; when present, R 8 and R 9 are each independently a divalent hydrocarbon, heterohydrocarbon, diorganosulfate or diorganophosphate group; and R 10 and R 11 are each independently H, hydroxy, hydrocarbon, heterohydrocarbon, silyl, silyloxy, alkoxysilyl, sulfo, phosphate or acrylate moiety (-OCOCH=CH2). In an embodiment, at least one of R 10 or R 11 is an acrylate moiety.

[0082] Examples of acrylate monomers include acrylates; N-alkyl acrylates (e.g., N-methyl acrylate, N-ethyl acrylate, N-n-propyl acrylate, N-isopropyl acrylate, N-n-butyl acrylate and N-tert-butyl acrylate); N-cycloalkyl acrylates (e.g., N-cyclohexyl acrylate); dialkyl acrylates (e.g., N,N-dimethyl acrylate and N,N-diallyl acrylate); dialkylaminoalkyl acrylates; hydroxyalkyl acrylates; N-aryl acrylates; methacrylates; N-alkyl methacrylates (e.g., N-methyl methacrylate, N-ethyl methacrylate, N-n-propyl methacrylate, N-isopropyl methacrylate, N-n-butyl methacrylate and N-tert-butyl methacrylate); N-cycloalkyl methacrylates; dialkyl methacrylates (e.g., N,N-dimethyl methacrylate); dialkylaminoalkyl methacrylates; hydroxyalkyl methacrylates; N-aryl methacrylates; and combinations thereof.

[0083] Examples of polyacrylate crosslinkers include diacrylates, dimethacrylates, triacrylates, trimethacrylates, tetraacrylates, tetramethacrylates, and combinations thereof. For example, when present, the polyacrylate crosslinker may comprise a polyol polyacrylate or polymethacrylate (e.g., ethylene glycol, propylene glycol, glycerol, trimethylolpropane, or pentaerythritol polyacrylate or polymethacrylate). Specific examples of polyacrylate crosslinkers include trimethylolpropane tri(meth)acrylate, pentaerythritol tetraacrylate (PETEA), pentaerythritol triacrylate, trimethylolpropane ethoxylate triacrylate, di(trimethylolpropane) tetraacrylate, dipentaerythritol polyacrylate, dipentaerythritol polymethacrylate, dipentaerythritol triacrylate, dipentaerythritol trimethacrylate, dipentaerythritol tetraacrylate, dipentaerythritol tetramethacrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, pentaerythritol poly(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol penta(meth)acrylate, pentaerythritol hexa(meth)acrylate, ethoxylated glycerol triacrylate, ε-caprolactone ethoxylated isocyanuric acid triacrylate, and ethoxylated isocyanuric acid triacrylate, tris(2-acryloyloxyethyl) isocyanurate, propoxylated glycerol triacrylate, ethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol di(meth)acrylate, ethylene glycol dimethacrylate (EDMA), polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polybutylene glycol di(meth)acrylate, 2,2-bis(4-(meth)acryloyloxyethoxyphenyl)propane, 2,2-bis(4-(meth)acryloyloxydiethoxyphenyl)propane, di(trimethylolpropane) tetra(meth)acrylate, or combinations thereof. In an embodiment, the polyacrylate crosslinker may include pentaerythritol tetraacrylate, trimethylolpropane ethoxylate triacrylate, trimethylolpropane triacrylate, or combinations thereof.

[0084] Examples of acrylonitrile monomers include acrylonitrile, methacrylonitrile, 2-hydroxyethyl acrylonitrile, methoxyacrylonitrile, methoxymethyl acrylonitrile, and combinations thereof.

[0085] In an embodiment, the acrylate monomer, optional polyacrylate crosslinker, optional acrylonitrile monomer, and / or their functional groups may be substituted or unsubstituted.

[0086] In embodiments where the polyacrylate comprises the optional polyacrylate crosslinker (i.e., where n is an integer greater than or equal to 1), the acrylate monomers and the polyacrylate crosslinker are covalently bonded to each other and can form a three-dimensional network of interconnected polyacrylate chains, where each polyacrylate chain comprises two or more acrylate monomers.

[0087] The liquid electrolyte permeates the polyacrylate and is formulated to provide good ionic conductivity to the polymer electrolyte 28. The liquid electrolyte comprises an organic solvent, a lithium salt in the organic solvent, and an optional additive. The liquid electrolyte can constitute greater than or equal to 70 wt%, or optionally greater than or equal to 80 wt%, and less than or equal to 99 wt%, or optionally less than or equal to 95 wt%, or optionally less than or equal to 90 wt% of the polymer electrolyte 28.

[0088] The organic solvent can include non-aqueous aprotic organic solvents. Non-limiting examples of non-aqueous aprotic organic solvents include cyclic carbonates (e.g., ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), fluoroethylene carbonate (FEC), and vinylene carbonate (VC)); linear carbonates (e.g., dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC)); aliphatic ethers (e.g., triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dimethoxypropane, 1,2-dimethoxyethane (DME), 1,2-diethoxyethane, and / or ethoxymethoxyethane); cyclic ethers (e.g., 1,4-dioxane, tetrahydrofuran, 2-methyltetrahydrofuran, and / or 1,3-dioxolane (DOL)); and combinations thereof. In an embodiment, the organic solvent can include an ether-based solvent. For example, in an embodiment, the organic solvent can comprise a mixture of a cyclic ether (e.g., DOL) and an aliphatic ether (e.g., DME). In this case, the cyclic ether and the aliphatic ether can be included in the liquid electrolyte in a volume ratio of about 1:1.

[0089] The lithium salt is soluble in the organic solvent and provides a channel for lithium ions through the polymer electrolyte 28. The lithium salt may include an inorganic lithium salt, an organic lithium salt, or a combination thereof. Examples of lithium salts include lithium hexafluorophosphate (LiPF6), lithium difluorophosphate (LiPO2F2), lithium perchlorate (LiClO4), lithium tetrachloroaluminate (LiAlCl4), lithium iodide (LiI), lithium bromide (LiBr), lithium thiocyanate (LiSCN), lithium tetrafluoroborate (LiBF4), lithium hexafluoroarsenate (LiAsF6), lithium trifluoromethanesulfonate (LiCF3SO3), lithium bis(trifluoromethane)sulfonimide (LiN(CF3SO2)2) (LiTFSI), lithium bis(fluorosulfonyl)imide (LiN(FSO2)2) (LiFSI), lithium tetraphenylborate (LiB(C6H5)4), lithium bis(oxalato)borate (LiB(C2O4)2) (LiBOB), lithium difluoro(oxalato)borate (LiBF2(C2O4)) (LiDFOB), and combinations thereof. In various aspects, the lithium salt may include LiFSI, LiTFSI, LiPF6, or a combination thereof. The lithium salt may be dissolved in the organic solvent at a concentration greater than or equal to about 0.5 Molar and less than or equal to about 1.5 Molar. In various aspects, the lithium salt may be dissolved in the organic solvent at a concentration of about 1 Molar. The lithium salt may constitute greater than or equal to about 5 wt%, optionally greater than or equal to about 10 wt%, and less than or equal to about 20 wt%, or optionally less than or equal to about 15 wt% of the polymer electrolyte 28.

[0090] The optional additive is soluble in the organic solvent and may be formulated to help prevent or inhibit polysulfide dissolution and shuttling. Examples of additives include lithium nitrate (LiNO3). When present, the optional additive may be dissolved in the organic solvent at a concentration greater than or equal to about 0.1 Molar and less than or equal to about 0.5 Molar. In various aspects, the optional additive may be dissolved in the organic solvent at a concentration of about 0.3 Molar.

[0091] The optional support structure may help provide mechanical stability to the polymer electrolyte 28 and may include a microporous nonwoven material impregnated, soaked, and / or encapsulated in the polymer electrolyte 28. For example, the support structure may include a mat of nonwoven fibers. The fibers may include a polymer (e.g., polyolefin and / or polyamide), glass, or a combination thereof. For example, the support structure may include a mat of nonwoven fibers of polypropylene (PP), polyethylene (PE), and / or polyethylene terephthalate (PET). The thickness of the support may be greater than or equal to 5 μm, optionally greater than or equal to 10 μm, and less than or equal to 200 μm, optionally less than or equal to 100 μm, or optionally less than or equal to 50 μm.

[0092] The negative electrode current collector 30 and the positive electrode current collector 32 are conductive and provide electrical connections between the external circuit 36 and the negative electrode 22 and the positive electrode 24, respectively. In various aspects, the negative electrode current collector 30 and the positive electrode current collector 32 can be made of metal and can be in the form of a non-porous metal foil, a perforated metal foil, a porous metal mesh, or a combination thereof. The negative electrode current collector 30 can be made of copper, nickel, or an alloy thereof, stainless steel, or other suitable conductive materials. The positive electrode current collector 32 can be made of aluminum (Al) or other suitable conductive materials.

[0093] Method

[0094] The battery pack 20 can be manufactured by assembling a stack including the negative electrode 22 and the positive electrode 24, wherein the negative electrode 22 and the positive electrode 24 are spaced apart from each other by a gap, impregnating the stack with a precursor electrolyte, and then initiating its free radical polymerization. The precursor electrolyte includes an acrylate monomer, an optional polyacrylate crosslinking agent, an optional acrylonitrile monomer, a free radical initiator, and a liquid electrolyte. The acrylate monomer, the optional polyacrylate crosslinking agent, the optional acrylonitrile monomer, and the liquid electrolyte can have substantially the same composition as the acrylate monomer, the optional polyacrylate crosslinking agent, the optional acrylonitrile monomer, and the liquid electrolyte described above with respect to the polymer electrolyte 28, and can be present in the precursor electrolyte in substantially the same proportions.

[0095] The free radical initiator can include a thermal polymerization initiator or a photo-polymerization initiator. Examples of thermal polymerization initiators include azo compounds, organic peroxides, and combinations thereof. Examples of azo compound initiators include azobisisobutyronitrile (AIBN), 1,1'-azobis(cyclohexanecarbonitrile) (ACHN), and combinations thereof. Examples of organic peroxide initiators include benzoyl peroxide, tert-butyl peracetate, and combinations thereof. Examples of photo-polymerization initiators include methyl benzoylformate (MBF). In an embodiment, the free radical initiator can include AIBN.

[0096] The free radical polymerization of the precursor electrolyte can be initiated such that the acrylate monomer, the optional polyacrylate crosslinking agent, and the optional acrylonitrile monomer are covalently bonded to each other and form a polyacrylate. The free radical polymerization of the precursor electrolyte can be initiated, for example, by heating the precursor electrolyte and / or by irradiating the precursor electrolyte with ultraviolet (UV) light. In an embodiment in which the free radical polymerization of the precursor electrolyte is initiated by heating, the precursor electrolyte can be heated at a temperature greater than or equal to 50 degrees Celsius (°C), optionally greater than or equal to 70 °C, or optionally greater than or equal to 100 °C.

[0097] The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Thus, while the disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon study of the drawings, the specification, and the appended claims. It should be understood that one or more steps within a method can be executed in different orders (or concurrently) without altering the principles of the disclosure. Further, although each of the embodiments above is described as having certain features, any one or more of those features described with respect to any embodiment of the invention can be implemented in and / or combined with any one of the features of any of the other embodiments, even if not explicitly described in that combination. In other words, the described embodiments are not mutually exclusive, and permutations and combinations of one or more of the embodiments with each other remain within the scope of the disclosure.

[0098] This application may include the following technical solutions.

[0099] 1. An electrolyte for a battery pack for recycling lithium ions, the electrolyte comprising:

[0100] a polyacrylate comprising acrylate monomers covalently bonded to each other;

[0101] a liquid electrolyte immobilized in the polyacrylate, the liquid electrolyte comprising a lithium salt in an organic solvent.

[0102] 2. The electrolyte according to aspect 1, wherein the acrylate monomers include acrylate, N-alkyl acrylate, N-cycloalkyl acrylate, dialkyl acrylate, hydroxyalkyl acrylate, N-aryl acrylate, methacrylate, N-alkyl methacrylate, N-cycloalkyl methacrylate, dialkyl methacrylate, dialkylaminoalkyl methacrylate, hydroxyalkyl methacrylate, N-aryl methacrylate, or a combination thereof.

[0103] 3. The electrolyte according to aspect 1, wherein at least one of the acrylate monomers comprises a substituent selected from silyl, silyloxy, alkoxysilyl, sulfo, and phosphate ester.

[0104] 4. The electrolyte according to aspect 1, wherein the polyacrylate further comprises a polyacrylate crosslinker, and wherein the acrylate monomers and the polyacrylate crosslinker are covalently bonded to each other to form a three-dimensional network of interconnected polyacrylate chains.

[0105] 5. The electrolyte according to Embodiment 1, wherein the polyacrylate crosslinking agent comprises ethylene glycol poly(meth)acrylate, propylene glycol poly(meth)acrylate, glycerol poly(meth)acrylate, trimethylolpropane poly(meth)acrylate, pentaerythritol poly(meth)acrylate, or a combination thereof.

[0106] 6. The electrolyte according to Embodiment 1, wherein the polyacrylate further comprises an acrylonitrile monomer, and wherein the acrylate monomer and the acrylonitrile monomer are covalently bonded to each other.

[0107] 7. The electrolyte according to Embodiment 1, wherein the polyacrylate comprises a polymer having the formula (1):

[0108]

[0109] Wherein:

[0110] m is an integer greater than 1;

[0111] n is zero or an integer;

[0112] p is zero or an integer;

[0113] q is zero or 1;

[0114] R 1 、R 3 、R 4 and R 5 are each independently H, a hydroxyl group, a hydrocarbon group, a heterohydrocarbon group, a silyl group, a siloxy group, an alkoxysilyl group, a sulfo group, a phosphate ester, or an acrylate moiety;

[0115] R 2 is a divalent hydrocarbon group or heterohydrocarbon group; and

[0116] L is a divalent hydrocarbon group, heterohydrocarbon group, or acrylate-containing moiety, and

[0117] the sum of m + n + p is greater than or equal to 100 and less than or equal to 200,000.

[0118] 8. The electrolyte according to Embodiment 7, wherein L is a divalent acrylate-containing moiety having the formula (2):

[0119]

[0120] Wherein:

[0121] a, b, c, and d are each independently zero or 1;

[0122] R 6 and R 7 are each independently a divalent hydrocarbon group or heterohydrocarbon group;

[0123] R 8 and R 9 are each independently a divalent hydrocarbon group, heterohydrocarbon group, diorganosulfate or diorganophosphate; and

[0124] R 10 and R 11 are each independently H, a hydroxyl group, a hydrocarbon group, a heterohydrocarbon group, a silyl group, a siloxy group, an alkoxysilyl group, a sulfo group, a phosphate or an acrylate moiety.

[0125] 9. The electrolyte according to embodiment 8, wherein at least one of R 10 or R 11 is an acrylate moiety.

[0126] 10. The electrolyte according to embodiment 1, wherein the organic solvent includes an ether-based solvent, and wherein the lithium salt includes lithium hexafluorophosphate (LiPF6), lithium bis(trifluoromethane)sulfonimide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), or a combination thereof.

[0127] 11. The electrolyte according to embodiment 1, further comprising an additive containing lithium nitrate (LiNO3).

[0128] 12. A battery pack for recycling lithium ions, the battery pack comprising:

[0129] a negative electrode comprising an electroactive negative electrode material;

[0130] a positive electrode spaced apart from the negative electrode by a gap, the positive electrode comprising an electroactive positive electrode material; and

[0131] a polymer electrolyte disposed in the gap between the negative electrode and the positive electrode, the polymer electrolyte comprising:

[0132] a polyacrylate comprising acrylate monomers covalently bonded to each other, and

[0133] a liquid electrolyte immobilized in the polyacrylate, the liquid electrolyte comprising an ether-based organic solvent, a lithium salt, and an additive, the lithium salt including lithium hexafluorophosphate (LiPF6), lithium bis(trifluoromethane)sulfonimide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), or a combination thereof, and the additive including lithium nitrate (LiNO3).

[0134] 13. The battery pack according to embodiment 12, wherein the acrylate monomer comprises acrylate, N-alkyl acrylate, N-cycloalkyl acrylate, dialkyl acrylate, hydroxyalkyl acrylate, N-aryl acrylate, methacrylate, N-alkyl methacrylate, N-cycloalkyl methacrylate, dialkyl methacrylate, dialkylaminoalkyl methacrylate, hydroxyalkyl methacrylate, N-aryl methacrylate, or a combination thereof.

[0135] 14. The battery pack according to embodiment 12, wherein at least one of the acrylate monomers comprises a substituent selected from silyl, siloxy, alkoxysilyl, sulfo, and phosphate ester.

[0136] 15. The battery pack according to embodiment 12, wherein the polyacrylate further comprises a polyacrylate crosslinking agent, and wherein the acrylate monomer and the polyacrylate crosslinking agent are covalently bonded to each other to form a three-dimensional network of interconnected polyacrylate chains.

[0137] 16. The battery pack according to embodiment 12, wherein the polyacrylate further comprises an acrylonitrile monomer, and wherein the acrylate monomer and the acrylonitrile monomer are covalently bonded to each other.

[0138] 17. The battery pack according to embodiment 12, wherein the polyacrylate comprises a polymer having the formula (1):

[0139]

[0140] Wherein:

[0141] m is an integer greater than 1;

[0142] n is zero or an integer;

[0143] p is zero or an integer;

[0144] q is zero or 1;

[0145] R 1 、R 3 、R 4 and R 5 are each independently H, hydroxy, hydrocarbyl, heterohydrocarbyl, silyl, siloxy, alkoxysilyl, sulfo, phosphate ester, or an acrylate moiety;

[0146] R 2 is a divalent hydrocarbyl or heterohydrocarbyl; and

[0147] L is a divalent hydrocarbyl, heterohydrocarbyl, or acrylate-containing moiety, and

[0148] The sum of m + n + p is greater than or equal to 100 and less than or equal to 200,000.

[0149] 18. The battery pack according to embodiment 17, wherein L is a divalent acrylate-containing moiety having formula (2):

[0150]

[0151] wherein:

[0152] a, b, c, and d are each independently zero or 1;

[0153] R 6 and R 7 are each independently a divalent hydrocarbon or hetero-hydrocarbon group;

[0154] R 8 and R 9 are each independently a divalent hydrocarbon, hetero-hydrocarbon, di-organic sulfate, or di-organic phosphate group; and

[0155] R 10 and R 11 are each independently H, a hydroxyl group, a hydrocarbon group, a hetero-hydrocarbon group, a silyl group, a siloxy group, an alkoxysilyl group, a sulfo group, a phosphate group, or an acrylate moiety, and

[0156] wherein at least one of R 10 or R 11 is an acrylate moiety.

[0157] 19. The battery pack according to embodiment 12, wherein the electroactive positive electrode material comprises a sulfur-based material, and wherein the electroactive negative electrode material comprises pore-free lithium.

[0158] 20. A method of manufacturing a battery pack for recycling lithium ions, the method comprising:

[0159] assembling a stack comprising a negative electrode and a positive electrode, the negative electrode and the positive electrode being spaced apart from each other by a gap;

[0160] impregnating the stack with an electrolyte precursor comprising an acrylate monomer, a radical initiator, and a liquid electrolyte; and

[0161] initiating radical polymerization of the acrylate monomer such that the acrylate monomers covalently bond to each other to form a polyacrylate.

Claims

1. A battery pack for circulating lithium ions, the battery pack comprising: A negative electrode comprising an electroactive negative electrode material; A positive electrode spaced apart from the negative electrode by a gap, the positive electrode comprising an electroactive positive electrode material; And A polymer electrolyte disposed within the gap between the negative electrode and the positive electrode, the polymer electrolyte comprising: A polyacrylate comprising acrylate monomers covalently bonded to each other, and A liquid electrolyte immobilized in the polyacrylate, the liquid electrolyte comprising an organic solvent and a lithium salt.

2. The battery pack according to claim 1, wherein the acrylate monomer comprises acrylate, N-alkyl acrylate, N-cycloalkyl acrylate, dialkyl acrylate, hydroxyalkyl acrylate, N-aryl acrylate, methacrylate, N-alkyl methacrylate, N-cycloalkyl methacrylate, dialkyl methacrylate, dialkylaminoalkyl methacrylate, hydroxyalkyl methacrylate, N-aryl methacrylate, or a combination thereof.

3. The battery pack according to claim 1, wherein at least one of the acrylate monomers comprises a substituent selected from silyl, siloxy, alkoxysilyl, sulfo, and phosphate ester.

4. The battery pack according to claim 1, wherein the polyacrylate further comprises a polyacrylate crosslinking agent, and wherein the acrylate monomer and the polyacrylate crosslinking agent are covalently bonded to each other to form a three-dimensional network of interconnected polyacrylate chains.

5. The battery pack according to claim 1, wherein the polyacrylate further comprises an acrylonitrile monomer, and wherein the acrylate monomer and the acrylonitrile monomer are covalently bonded to each other.

6. The battery pack according to claim 1, wherein the polyacrylate comprises a polymer having the formula (1): Wherein: m is an integer greater than 1; n is zero or an integer; p is zero or an integer; q is zero or 1; R 1 、R 3 、R 4 and R 5 each independently is H, a hydroxyl group, a hydrocarbon group, a heterohydrocarbon group, a silyl group, a siloxy group, an alkoxysilyl group, a sulfo group, a phosphate ester or an acrylate moiety; R 2 is a divalent hydrocarbyl or heterohydrocarbyl group; and L is a divalent hydrocarbon group, heterohydrocarbon group, or acrylate-containing moiety, and The sum of m + n + p is greater than or equal to 100 and less than or equal to 200,000.

7. The battery pack according to claim 6, wherein L is a divalent acrylate-containing moiety having the formula (2): Wherein: a, b, c, and d are each independently zero or 1; R 6 and R 7 each independently represents a divalent hydrocarbon group or hetero-hydrocarbon group; R 8 and R 9 each independently represents a divalent hydrocarbon group, hetero-hydrocarbon group, di-organic sulfate or di-organic phosphate; and R 10 and R 11 each independently is an H, hydroxyl, hydrocarbon group, heterohydrocarbon group, silyl, silyloxy, alkoxysilyl, sulfo, phosphate or acrylate moiety, and wherein R 10 or R 11 at least one of which is an acrylate moiety.

8. The battery pack according to claim 1, wherein the electroactive positive electrode material comprises a sulfur-based material, and wherein the electroactive negative electrode material comprises pore-free lithium.

9. The battery pack according to claim 1, wherein the organic solvent comprises an ether-based solvent, and wherein the lithium salt comprises lithium hexafluorophosphate (LiPF6), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), or a combination thereof.

10. The battery pack according to claim 1, further comprising an additive, the additive comprising lithium nitrate (LiNO3).

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