Electrolyte additive for capacitor-assisted battery

Abstract

Electrolyte additives for capacitor-assisted batteries. A capacitor-assisted battery is provided. The capacitor-assisted battery includes an electrolyte system having a lithium ion-conducting component and one or more additives. The one or more additives include a first additive including 3-trimethylsilylphenylboronic acid and a second additive including succinic anhydride. The capacitor-assisted battery includes an electrode having an electroactive material and a capacitor material. The electroactive material has a first coating defined thereon, and the capacitor material has a second coating defined thereon. The first and second coatings are defined by the first and second additives. The first coating is substantially continuous, covering greater than or equal to about 80% of a total exposed surface area of the electroactive material. The second coating is a discontinuous coating covering greater than or equal to about 20% to less than or equal to about 80% of a total exposed surface area of the capacitor material.

Description

Technical Field

[0001] This disclosure relates to an electrolyte system for a capacitor-assisted battery pack, a capacitor-assisted battery pack, and a capacitor-assisted battery pack. Background Technology

[0002] This section provides background information relating to this disclosure, which is not necessarily prior art.

[0003] Advanced energy storage devices and systems are needed to meet the energy and / or power requirements of a variety of products, including automotive products such as start-stop systems (e.g., 12V start-stop systems), micro battery pack auxiliary systems (μBAS), hybrid electric vehicles (“HEVs”), and electric vehicles (“EVs”). For example, capacitors can provide high power density (e.g., about 10 kW / kg) in power-based applications, while lithium-ion battery packs can deliver high energy density (e.g., about 100 Wh / kg to 300 Wh / kg). In various cases, capacitor-assisted battery packs (“CABs”) (e.g., lithium-ion capacitors mixed with lithium-ion battery packs in a single cell core) can offer several advantages, including enhanced power capacity compared to lithium-ion battery packs. For example, integrated capacitor materials or supercapacitor materials can be used to provide crank current during engine starting, limiting the current drawn from the lithium-ion battery pack during starting, particularly in cold-weather applications such as cold starts. However, in some cases, capacitor-assisted systems experience relatively low energy density. For example, capacitor-assisted systems typically have increased electrolyte requirements due to the relatively large surface area and low capacity of capacitor auxiliary materials. Furthermore, capacitor auxiliary materials can be particularly susceptible to undesirable side reactions (e.g., outgassing) when in contact with electrolyte solvents. Therefore, it is desirable to develop capacitor-assisted battery packs or hybrid devices and systems that possess both enhanced power capacity and increased energy density. Summary of the Invention

[0004] This section provides a general overview of this disclosure and is not a full disclosure of its entire scope or all its features.

[0005] This disclosure relates to an electrolyte system for capacitor-assisted electrochemical cells.

[0006] In various aspects, this disclosure provides an electrolyte system for a capacitor-assisted battery pack. The electrolyte system may include a lithium-ion conducting component, a first additive comprising 3-trimethylsilylphenylboronic acid (TMSPB) at a concentration greater than or equal to about 0.1 wt% to less than or equal to about 5 wt%, and a second additive comprising succinic anhydride (SA) at a concentration greater than or equal to about 0.1 wt% to less than or equal to about 5 wt%.

[0007] In one aspect, the lithium-ion conducting component may be a lithium salt selected from the following: lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4), lithium tetrachloroaluminate (LiAlCl4), lithium iodide (LiI), lithium bromide (LiBr), lithium thiocyanate (LiSCN), lithium tetrafluoroborate (LiBF4), lithium tetraphenylborate (LiB(C6H5)4), lithium bis(oxalate)borate (LiB(C2O4)2)(LiBOB), lithium difluorooxalate borate (LiBF2(C2O4)), lithium hexafluoroarsenate (LiAsF6), lithium trifluoromethanesulfonate (LiCF3SO3), lithium bis(trifluoromethane)sulfonylimide (LiN(CF3SO2)2), lithium bis(fluorosulfonylimide) (LiN(FSO2)2) (LiSFI), lithium bis(trifluoromethanesulfonylimide) (LiTFSI), and combinations thereof.

[0008] In one respect, the electrolyte system may have a lithium salt concentration of greater than or equal to about 0.6 M to less than or equal to about 2.0 M.

[0009] In one aspect, the electrolyte system may further include solvents selected from: ethylene carbonate (EC), propylene carbonate (PC), butyl carbonate (BC), fluoroethylene carbonate (FEC), dimethyl carbonate (DMC), diethyl carbonate (DEC), methyl methyl carbonate (EMC), methyl formate, methyl acetate, methyl propionate, γ-butyrolactone, γ-valerolactone, and combinations thereof.

[0010] In various aspects, this disclosure provides a capacitor-assisted battery pack. The capacitor-assisted battery pack may include a capacitor-assisted electrode. The capacitor-assisted electrode includes, for example, a capacitor material and an electroactive material for cycling lithium ions. The capacitor-assisted electrode may further include an electrolyte system. The electrolyte system may include a lithium-ion conducting component, 3-trimethylsilylphenylboronic acid (TMSPB), and succinic anhydride (SA). 3-trimethylsilylphenylboronic acid (TMSPB) and succinic anhydride (SA) may together define a first coating on the electroactive material and a second coating on the capacitor material.

[0011] In one aspect, the electrolyte system may contain greater than or equal to about 0.1 wt% to less than or equal to about 5 wt% of 3-trimethylsilylphenylboronic acid (TMSPB) and greater than or equal to about 0.1 wt% to less than or equal to about 5 wt% of succinic anhydride (SA).

[0012] In one respect, the first coating may be substantially continuous, covering more than or equal to about 80% of the total exposed surface area of ​​the electroactive material.

[0013] In one respect, the first coating may have an average thickness greater than or equal to about 1 nm to less than or equal to about 100 nm.

[0014] In one respect, the second coating may be a discontinuous coating with multiple pores.

[0015] In one respect, the second coating may cover more than or equal to about 20% to less than or equal to about 80% of the total exposed surface area of ​​the capacitor material.

[0016] In one respect, the second coating may have an average thickness of more than or equal to about 1 nm to less than or equal to about 500 nm.

[0017] In one aspect, the lithium-ion conducting component can be a lithium salt selected from the following: lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4), lithium tetrachloroaluminate (LiAlCl4), lithium iodide (LiI), lithium bromide (LiBr), lithium thiocyanate (LiSCN), lithium tetrafluoroborate (LiBF4), lithium tetraphenylborate (LiB(C6H5)4), lithium bis(oxalate)borate (LiB(C2O4)2)(LiBOB), lithium difluorooxalate borate (LiBF2(C2O4)), lithium hexafluoroarsenate (LiAsF6), lithium trifluoromethanesulfonate (LiCF3SO3), lithium bis(trifluoromethane)sulfonylimide (LiN(CF3SO2)2), lithium bis(fluorosulfonyl)imide (LiN(FSO2)2)(LiSFI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and combinations thereof.

[0018] In one respect, the electrolyte system may have a lithium salt concentration of greater than or equal to about 0.6 M to less than or equal to about 2.0 M.

[0019] In one aspect, the electrolyte system may further include solvents selected from: ethylene carbonate (EC), propylene carbonate (PC), butyl carbonate (BC), fluoroethylene carbonate (FEC), dimethyl carbonate (DMC), diethyl carbonate (DEC), methyl methyl carbonate (EMC), methyl formate, methyl acetate, methyl propionate, γ-butyrolactone, γ-valerolactone, and combinations thereof.

[0020] In one respect, electroactive materials can be positively electroactive materials.

[0021] In one respect, the positively charged active material can be selected from: LiNi x Mn y Co z Al (1-x-y-z) O2 (where 0.33≤x≤0.96, 0.03≤y≤0.33, 0.005≤z≤0.33), LiNi x Mn y Co 1-x-y O2 (where 0.33≤x≤0.96, 0.04≤y≤0.33), LiNi x Mn 1-x O2 (where 0 ≤ x ≤ 1) and its combinations.

[0022] In various aspects, this disclosure provides a capacitor-assisted battery pack. The capacitor-assisted battery pack may include an electrolyte system. The electrolyte system may include a lithium-ion conducting component, a first additive, and a second additive. The first additive may include 3-trimethylsilylphenylboronic acid (TMSPB). The second additive may include succinic anhydride (SA). The capacitor-assisted battery pack may also include a capacitor-assisted electrode. The capacitor-assisted electrode may include an electroactive material having a first coating thereon and a capacitor material having a second coating thereon. The first and second coatings may be defined by the first and second additives. The first coating may be substantially continuous, covering more than or equal to about 80% of the total exposed surface area of ​​the electroactive material. The second coating may be a discontinuous coating covering more than or equal to about 20% to less than or equal to about 80% of the total exposed surface area of ​​the capacitor material.

[0023] In one aspect, the electrolyte system may contain a first additive of greater than or equal to about 0.1% by weight and less than or equal to about 5% by weight, and a second additive of greater than or equal to about 0.1% by weight and less than or equal to about 5% by weight.

[0024] In one aspect, the lithium-ion conducting component may include a lithium salt. The electrolyte system may have a lithium salt concentration greater than or equal to about 0.6 M to less than or equal to about 2.0 M.

[0025] In one aspect, the first coating may have an average thickness greater than or equal to about 1 nm and less than or equal to about 100 nm. The second coating may have an average thickness greater than or equal to about 1 nm and less than or equal to about 500 nm.

[0026] This invention discloses the following embodiments: 1. An electrolyte system for a capacitor-assisted battery pack, the electrolyte system comprising: Lithium-ion conducting components; A first additive comprising 3-trimethylsilylphenylboronic acid (TMSPB) at a concentration greater than or equal to about 0.1% by weight and less than or equal to about 5% by weight; and A second additive containing succinic anhydride (SA) of greater than or equal to about 0.1% by weight and less than or equal to about 5% by weight.

[0027] 2. According to the electrolyte system of embodiment 1, wherein the lithium-ion conducting component is a lithium salt selected from the following: lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4), lithium tetrachloroaluminate (LiAlCl4), lithium iodide (LiI), lithium bromide (LiBr), lithium thiocyanate (LiSCN), lithium tetrafluoroborate (LiBF4), lithium tetraphenylborate (LiB(C6H5)4), lithium bis(oxalate)borate (LiB(C2O4)2)(LiBOB), lithium difluorooxalate borate (LiBF2(C2O4)), lithium hexafluoroarsenate (LiAsF6), lithium trifluoromethanesulfonate (LiCF3SO3), lithium bis(trifluoromethane)sulfonylimide (LiN(CF3SO2)2), lithium bis(fluorosulfonyl)imide (LiN(FSO2)2) (LiSFI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and combinations thereof.

[0028] 3. The electrolyte system according to embodiment 2, wherein the electrolyte system has a lithium salt concentration greater than or equal to about 0.6 M to less than or equal to about 2.0 M.

[0029] According to the electrolyte system of embodiment 1, the electrolyte system further comprises a solvent selected from the following: ethylene carbonate (EC), propylene carbonate (PC), butyl carbonate (BC), fluoroethylene carbonate (FEC), dimethyl carbonate (DMC), diethyl carbonate (DEC), methyl methyl carbonate (EMC), methyl formate, methyl acetate, methyl propionate, γ-butyrolactone, γ-valerolactone, and combinations thereof.

[0030] 5. A capacitor-assisted battery pack, comprising: A capacitor auxiliary electrode, the capacitor auxiliary electrode comprising a capacitor material and an electroactive material for cycling lithium ions; and An electrolyte system comprising: Lithium-ion conducting components; 3-Trimethylsilylphenylboronic acid (TMSPB); and Succinic anhydride (SA) and 3-trimethylsilylphenylboronic acid (TMSPB) together define a first coating on an electroactive material and a second coating on a capacitor material.

[0031] 6. The capacitor-assisted battery pack according to embodiment 5, wherein the electrolyte system comprises more than or equal to about 0.1 wt% to less than or equal to about 5 wt% of 3-trimethylsilylphenylboronic acid (TMSPB) and more than or equal to about 0.1 wt% to less than or equal to about 5 wt% of succinic anhydride (SA).

[0032] 7. According to embodiment 5, the capacitor-assisted battery pack, wherein the first coating is substantially continuous and covers more than or equal to about 80% of the total exposed surface area of ​​the electroactive material.

[0033] 8. The capacitor-assisted battery pack according to embodiment 5, wherein the first coating has an average thickness greater than or equal to about 1 nm to less than or equal to about 100 nm.

[0034] 9. The capacitor-assisted battery pack according to embodiment 5, wherein the second coating is a discontinuous coating having multiple pores.

[0035] 10. According to embodiment 9, the capacitor-assisted battery pack, wherein the second coating covers a total exposed surface area of ​​the capacitor material that is greater than or equal to about 20% to less than or equal to about 80%.

[0036] 11. According to embodiment 5, the capacitor-assisted battery pack, wherein the second coating has an average thickness of more than or equal to about 1 nm and less than or equal to about 500 nm.

[0037] 12. The capacitor-assisted battery pack according to embodiment 5, wherein the lithium-ion conducting component is selected from the following lithium salts: lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4), lithium tetrachloroaluminate (LiAlCl4), lithium iodide (LiI), lithium bromide (LiBr), lithium thiocyanate (LiSCN), lithium tetrafluoroborate (LiBF4), lithium tetraphenylborate (LiB(C6H5)4), lithium bis(oxalate)borate (LiB(C2O4)2)(LiBOB), lithium difluorooxalate borate (LiBF2(C2O4)), lithium hexafluoroarsenate (LiAsF6), lithium trifluoromethanesulfonate (LiCF3SO3), lithium bis(trifluoromethane)sulfonylimide (LiN(CF3SO2)2), lithium bis(fluorosulfonylimide) (LiN(FSO2)2) (LiSFI), lithium bis(trifluoromethanesulfonylimide) (LiTFSI), and combinations thereof.

[0038] 13. The capacitor-assisted battery pack according to embodiment 12, wherein the electrolyte system has a lithium salt concentration of greater than or equal to about 0.6M and less than or equal to about 2.0M.

[0039] 14. The capacitor-assisted battery pack according to embodiment 5, wherein the electrolyte system further comprises a solvent selected from the following: ethylene carbonate (EC), propylene carbonate (PC), butyl carbonate (BC), fluoroethylene carbonate (FEC), dimethyl carbonate (DMC), diethyl carbonate (DEC), methyl methyl carbonate (EMC), methyl formate, methyl acetate, methyl propionate, γ-butyrolactone, γ-valerolactone, and combinations thereof.

[0040] 15. The capacitor-assisted battery pack according to embodiment 5, wherein the electroactive material is a positively active material.

[0041] 16. The capacitor-assisted battery pack according to embodiment 15, wherein the positively active material is selected from: LiNi x Mn y Co z Al (1-x-y-z) O2 (where 0.33≤x≤0.96, 0.03≤y≤0.33, 0.005≤z≤0.33), LiNi x Mn y Co 1-x-y O2 (where 0.33≤x≤0.96 and 0.04≤y≤0.33), LiNi x Mn 1-x O2 (where 0≤x≤1) and its combinations.

[0042] 17. A capacitor-assisted battery pack, comprising: An electrolyte system comprising: Lithium-ion conducting components; The first additive contains 3-trimethylsilylphenylboronic acid (TMSPB); and A second additive containing succinic anhydride (SA); and A capacitor auxiliary electrode, comprising: An electroactive material having a first coating defined thereon, the first coating being substantially continuous and covering more than or equal to about 80% of the total exposed surface area of ​​the electroactive material, the first coating being defined by a first additive and a second additive; and A capacitor material having a second coating defined thereon, the second coating being a discontinuous coating covering more than or equal to about 20% to less than or equal to about 80% of the total exposed surface area of ​​the capacitor material, the second coating also being defined by the first additive and the second additive.

[0043] 18. A capacitor-assisted battery pack according to embodiment 17, wherein the electrolyte system comprises a first additive of greater than or equal to about 0.1% by weight and less than or equal to about 5% by weight, and A second additive, greater than or equal to about 0.1% by weight and less than or equal to about 5% by weight.

[0044] 19. The capacitor-assisted battery pack according to embodiment 17, wherein the lithium-ion conducting component comprises a lithium salt, and the electrolyte system has a lithium salt concentration greater than or equal to about 0.6 M to less than or equal to about 2.0 M.

[0045] 20. The capacitor-assisted battery pack according to embodiment 17, wherein the first coating has an average thickness greater than or equal to about 1 nm and less than or equal to about 100 nm, and The second coating has an average thickness of about 1 nm to about 500 nm.

[0046] Further areas of application will become apparent from the description provided herein. The descriptions and specific examples in this disclosure are for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0047] The accompanying drawings described herein are for illustrative purposes only, for the purposes of selecting embodiments and not all possible implementations, and are not intended to limit the scope of this disclosure.

[0048] Figure 1 This is an illustration of an exemplary capacitor-assisted electrochemical battery pack including first and second electrolyte additives according to various aspects of this disclosure; Figure 2A This is a diagram of a positively active material having a cathode electrolyte interphase layer formed on a positively active material, according to various aspects of this disclosure; Figure 2B These are transmission electron microscope (TEM) images of exemplary positively active materials having a cathode electrolyte interphase layer formed on a positively active material, according to various aspects of this disclosure. Figure 3A A diagram illustrating a capacitor material having a cathode electrolyte interface layer formed on a capacitor material, according to various aspects of this disclosure; Figure 3B Transmission electron microscopy (TEM) images of capacitor materials having a cathode electrolyte interface layer formed on the capacitor material, according to various aspects of this disclosure; Figure 4A This is an illustration of the capacity retention of an exemplary battery pack including first and second electrolyte additives according to various aspects of this disclosure; Figure 4B This is an illustration of the capacity retention of an exemplary battery pack including first and second electrolyte additives according to various aspects of this disclosure; Figure 5A This is an illustration showing a self-discharge test of an exemplary battery pack including first and second electrolyte additives according to various aspects of this disclosure; Figure 5B This is a diagram illustrating the current response of an exemplary battery pack including first and second electrolyte additives according to various aspects of this disclosure; and Figure 5C This is a diagram illustrating the current response of an exemplary battery pack including first and second electrolyte additives according to various aspects of this disclosure.

[0049] In the various views of the accompanying drawings, the corresponding reference numerals denote the respective components. Detailed Implementation

[0050] Exemplary embodiments are provided to make this disclosure complete and to fully communicate its scope to those skilled in the art. Numerous specific details, such as examples of specific components, parts, apparatuses, and methods, are set forth to provide a full understanding of embodiments of this disclosure. It will be apparent to those skilled in the art that specific details are not required, that exemplary embodiments may be presented in many different forms, and that none of them should be construed as limiting the scope of this disclosure. In some exemplary embodiments, well-known methods, well-known apparatus structures, and well-known techniques are not described in detail.

[0051] The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” are intended to include the plural forms as used herein. The terms “comprising,” “including,” “covering,” and “having” are concurrent and thus specify the presence of the stated features, elements, compositions, steps, integers, operations, and / or components, but do not exclude the presence or inclusion of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Although the open-ended term “comprising” should be understood as a non-limiting term used to describe and claim the various embodiments described herein, in some respects it may be understood alternatively to more restrictive and limiting terms such as “consisting of” or “substantially consisting of.” Thus, for any given embodiment recounting a composition, material, component, element, feature, integer, operation, and / or method step, this disclosure also specifically includes embodiments consisting of or substantially consisting of such recounted compositions, materials, components, elements, features, integers, operations, and / or method steps. In the case of “consisting of…”, the alternative embodiments exclude any additional compositions, materials, components, elements, features, integers, operating and / or method steps. In the case of “essentially composed of…”, any additional compositions, materials, components, elements, features, integers, operating and / or method steps that substantially affect the essential and novel characteristics are excluded from such embodiments. However, any compositions, materials, components, elements, features, integers, operating and / or method steps that do not substantially affect the essential and novel characteristics may be included in the embodiments.

[0052] Any methods, procedures, and operations described herein should not be construed as necessarily requiring them to be performed in the specific order discussed or illustrated, unless explicitly stated as such. It should also be understood that, unless otherwise stated, additional or alternative steps may be employed.

[0053] When a component, element, or layer is mentioned as being “on,” “engaged,” “connected,” or “coupled” to another component or layer, it may be directly engaged, connected, or coupled to the other component, element, or layer, or an intermediary element or layer may be present. Conversely, when an element is mentioned as being “directly on,” “directly engaged,” “directly connected,” or “directly coupled” to another component or layer, an intermediary element or layer may not be present. Other terms used to describe relationships between elements should be interpreted similarly (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and / or” includes any and all combinations of one or more of the related enumerations.

[0054] Although the terms first, second, third, etc., may be used herein to describe various steps, elements, components, regions, layers, and / or sections, these steps, elements, components, regions, layers, and / or sections should not be limited by these terms unless otherwise stated. These terms may be used only to distinguish one step, element, component, region, layer, or section from another. Unless the context clearly indicates otherwise, terms such as “first,” “second,” and other numerical terms used herein do not imply order or sequence. Therefore, the first step, element, component, region, layer, or section discussed below may be referred to as the second step, element, component, region, layer, or section without departing from the teachings of the exemplary embodiments.

[0055] For ease of description, spatially or temporally relative terms such as “before,” “after,” “inner,” “outer,” “below,” “below,” “lower,” “above,” “upper,” etc., may be used herein to describe the relationship of one element or feature as shown in the accompanying drawings to other elements or features(s). In addition to the orientations shown in the accompanying drawings, spatially or temporally relative terms may be intended to cover different orientations of the apparatus or system during use or operation.

[0056] Throughout this disclosure, numerical values ​​represent approximate measurements or range limits to cover slight deviations from a given value and embodiments that substantially have the mentioned value as well as embodiments that precisely have the mentioned value. Except in the detailed description of the working examples provided at the end, all numerical values ​​of parameters (e.g., quantities or conditions) in this specification (including the appended claims) should be understood to be modified in all cases by the term “about,” regardless of whether “about” actually precedes the numerical value. “About” means both the exact or precise numerical value and the fact that the numerical value allows for a certain degree of slight inaccuracy (a value that is somewhat close to the exact value; roughly or reasonably approximating the value; almost). If the inaccuracy provided by “about” is not otherwise understood in the art in this ordinary sense, then “about” as used herein refers to at least a deviation that can be caused by common methods of measuring and using such parameters. For example, “about” may include deviations of less than or equal to 5%, optionally less than or equal to 4%, optionally less than or equal to 3%, optionally less than or equal to 2%, optionally less than or equal to 1%, optionally less than or equal to 0.5%, and in some respects optionally less than or equal to 0.1%.

[0057] In addition, the disclosure of the range includes disclosure of all values ​​throughout the range and disclosure of further subdivisions of the range, including disclosure of endpoints and subranges given by the range.

[0058] Exemplary embodiments will now be described more fully with reference to the accompanying drawings.

[0059] This technology relates to improved electrochemical batteries comprising one or more capacitor components or additives, which can be incorporated into energy storage devices, such as lithium-ion battery packs. Such electrochemical battery packs may have a hybrid structure to integrate the high power density of capacitors with the high energy density of lithium-ion battery packs. In various cases, electrochemical batteries and energy storage devices prepared according to aspects of this disclosure can be used, for example, in vehicle or automotive transportation applications (e.g., motorcycles, boats, tractors, buses, motorcycles, mobile homes, campers, and tanks). However, this technology can be used in a wide variety of other industries and applications, including aerospace components, consumer products, equipment, buildings (e.g., houses, offices, sheds, and warehouses), office equipment and furniture, and industrial equipment machinery, agricultural or farm equipment, or heavy machinery, as non-limiting examples.

[0060] A typical lithium-ion battery pack includes a first electrode (e.g., a positive electrode or a cathode) opposite a second electrode (e.g., a negative electrode or anode) and a separator and / or electrolyte disposed therebetween. Typically, in a lithium-ion battery pack, the battery pack or cells can be electrically connected in a stacked or wound configuration to increase total output. A lithium-ion battery pack operates by reversibly transferring lithium ions between the first and second electrodes. For example, lithium ions can move from the positive electrode to the negative electrode during charging and in the opposite direction during discharging. The electrolyte is adapted to conduct lithium ions and can be in liquid, gel, or solid form.

[0061] In the case of hybrid battery packs or capacitor-assisted battery packs (“CABs”), capacitor materials used as capacitors can be integrated into the lithium-ion battery pack or battery stack. For example, in various aspects, a capacitor-assisted battery pack may include one or more capacitor components or layers that are parallel to or stacked with one or more electrodes of a conventional lithium-ion battery pack. In other aspects, a capacitor-assisted battery pack may include one or more capacitor materials or additives incorporated into one or more electrodes of a conventional lithium-ion battery pack. In each variant, capacitor-assisted battery packs offer several advantages, including, for example, enhanced energy density (Wh / kg) and power density (W / kg), as well as improved long-term performance. For example, energy density can be increased by selecting suitable electroactive materials, while power density can be increased by incorporating different amounts of capacitor components or materials.

[0062] Figure 1An exemplary and schematic diagram of a capacitor-assisted electrochemical cell (also known as a battery pack or battery bank) 20 is shown. The battery pack 20 includes a negative electrode 22 (e.g., an anode), a positive electrode 24 (e.g., a cathode), and a separator 26 disposed between the two electrodes 22, 24. The separator 26 provides electrical isolation—preventing physical contact—between the electrodes 22, 24. The separator 26 also provides a minimal resistance path through which lithium ions (and in some cases, associated anions) pass internally during lithium-ion cycling. In various aspects, the separator 26 includes an electrolyte 30, which may also be present in the negative electrode 22 and the positive electrode 24 in some aspects. In some variations, the separator 26 may be formed of a solid electrolyte or a semi-solid electrolyte (e.g., a gel electrolyte). For example, the separator 26 may be defined by a plurality of solid electrolyte particles. In the case of solid-state battery packs and / or semi-solid-state battery packs, the positive electrode 24 and / or the negative electrode 22 may comprise a plurality of solid electrolyte particles. The plurality of solid electrolyte particles included in or defining the separator 26 may be the same as or different from the plurality of solid electrolyte particles included in the positive electrode 24 and / or the negative electrode 22.

[0063] The first current collector 32 (e.g., a negative current collector) may be located at or near the negative electrode 22. The first current collector 32 may be a metal foil, metal grid or mesh, or porous metal containing copper or any other suitable electronically conductive material known to those skilled in the art. The second current collector 34 (e.g., a positive current collector) may be located at or near the positive electrode 24. The second electrode current collector 34 may be a metal foil, metal grid or mesh, or porous metal containing aluminum or any other suitable electronically conductive material known to those skilled in the art. The first current collector 32 and the second current collector 34 may respectively collect and move free electrons to and from the external circuit 40. For example, the interruptible external circuit 40 and the load device 42 may be connected to the negative electrode 22 (via the first current collector 32) and the positive electrode 24 (via the second current collector 34).

[0064] Battery pack 20 can generate current during discharge via a reversible electrochemical reaction that occurs when external circuit 40 is closed (to connect negative electrode 22 and positive electrode 24) and negative electrode 22 has a lower potential than positive electrode. The potential difference between positive electrode 24 and negative electrode 22 drives electrons generated by the reaction at negative electrode 22 (e.g., oxidation of lithium intercalation) to move through external circuit 40 towards positive electrode 24. Lithium ions also generated at negative electrode 22 simultaneously transfer to positive electrode 24 via electrolyte 30 contained in separator 26. Electrons flow through external circuit 40, and lithium ions migrate through separator 26 containing electrolyte 30, forming intercalated lithium at positive electrode 24. As described above, electrolyte 30 is also typically present in negative electrode 22 and positive electrode 24. The current flowing through external circuit 40 can be utilized and directed through load device 42 until the lithium in negative electrode 22 is depleted and the capacity of battery pack 20 decreases.

[0065] By connecting an external power source to the lithium-ion battery pack 20 to reverse the electrochemical reactions that occur during battery pack discharge, the battery pack 20 can be charged or recharged at any time. Connecting an external power source to the battery pack 20 facilitates a reaction at the positive electrode 24, such as the non-spontaneous oxidation of intercalated lithium, thereby generating electrons and lithium ions. Lithium ions flow back through the electrolyte 30, through the separator 26, and towards the negative electrode 22 to replenish the negative electrode 22 with lithium (e.g., intercalated lithium) used during the next battery pack discharge event. Thus, a full discharge event followed by a full charge event is considered a cycle in which lithium ions circulate between the positive electrode 24 and the negative electrode 22. External power sources that can be used to charge the battery pack 20 may vary depending on the size, construction, and specific end use of the battery pack 20. Some notable and exemplary external power sources include, but are not limited to, AC-DC converters and vehicle alternators connected to the AC mains via a wall power outlet.

[0066] Although the examples shown include a single cathode (i.e., positive electrode 24) and a single anode (i.e., negative electrode 22), those skilled in the art will recognize that this teaching extends to a variety of other configurations, including those having one or more cathodes and one or more anodes, and various current collectors having electroactive layers disposed on or adjacent to one or more of their surfaces. For example, in many lithium-ion battery pack configurations, each of the first current collector 32, negative electrode 22, separator 26, positive electrode 24, and second current collector 34 is fabricated as a relatively thin layer (e.g., with a thickness from a few micrometers to a fraction of a millimeter or less), and the connected layers are assembled in an electrically parallel arrangement to provide suitable power and energy packaging.

[0067] The size and shape of the battery pack 20 can vary depending on the specific application it is designed for. For example, battery-powered vehicles and handheld consumer electronics are two examples where the battery pack 20 would likely be designed with different sizes, capacities, and power output specifications. The battery pack 20 can be connected in series or parallel with other similar lithium-ion batteries or battery packs to generate greater voltage output, energy, and power when the load device 42 requires it. Thus, the battery pack 20 can generate current to the load device 42, which is part of the external circuit 40. When the battery pack 20 discharges, the load device 42 can be powered by the current flowing through the external circuit 40. While the electrical load device 42 can be any number of known electrical devices, some specific examples include electric motors for electric vehicles, laptop computers, tablet computers, cellular phones, and cordless power tools or appliances. The load device 42 can also be a generator that charges the battery pack 20 for the purpose of storing electrical energy.

[0068] In various aspects, the battery pack 20 may also include a variety of other components, although not shown here, but which are known to those skilled in the art. For example, the battery pack 20 may include a housing, gaskets, terminal covers, tabs, battery pack terminals, and any other conventional components or materials that may be located within or around the battery pack 20 (including between or around the negative terminal 22, positive terminal 24, and / or separator 26). Furthermore, although... Figure 1 The battery pack 20 shown includes a liquid electrolyte 30. As mentioned above, this technology is also applicable to solid-state battery packs and / or semi-solid-state battery packs, which include solid electrolytes and / or solid electrolyte particles and / or semi-solid electrolytes and / or solid electroactive particles, which may have different designs known to those skilled in the art.

[0069] Refer again Figure 1 The negative electrode 22 may be formed of a lithium host material capable of serving as the negative terminal of the battery pack 20. In various aspects, the negative electrode 22 may be defined by a plurality of negatively active material particles. Such negatively active material particles may be disposed in one or more layers to define the three-dimensional structure of the negative electrode 22. For example, the negative electrode 22 may have an average thickness greater than or equal to about 1 μm and less than or equal to about 500 μm, and in some aspects, optionally greater than or equal to about 10 μm and less than or equal to about 200 μm. The electrolyte 30 may be introduced, for example, after battery assembly and is contained within the pores of the negative electrode 22. In some variations, the negative electrode 22 may comprise a plurality of solid electrolyte particles.

[0070] The negative electrode 22 may include a negatively active material, such as lithium, for example, a lithium alloy (e.g., lithium titanium oxide (LTO)) and / or lithium metal. In some variations, the negative electrode may be a film or layer formed of lithium metal. Other materials may also be used to form the negative electrode 22, including, for example, carbonaceous materials (e.g., graphite, hard carbon, soft carbon) and / or lithium-silicon, silicon-containing binary and ternary alloys (e.g., Si, Li-Si, SiO). x (where 0≤x≤2), FeS, etc.) and / or tin-containing alloys (e.g., Si-Sn, SiSnFe, SiSnAl, SiFeCo, SnO2, etc.) and / or metal oxides (e.g., Li4Ti5O) 12 (e.g., V₂O₅, SnO₂, Co₃O₄, etc.) and / or combinations thereof. For example, in some variations, the negatively charged active material may include a carbonaceous-silicon based composite, comprising, for example, about 10% by weight of SiO₂. x (where 0 ≤ x ≤ 2) and approximately 90% by weight of graphite. Furthermore, in some variations, the negatively charged active material may be pre-lithiated.

[0071] In various aspects, the negatively active material in the negative electrode 22 may optionally be mixed (e.g., slurry casting) with one or more electronically conductive materials that provide an electron conduction path and / or at least one polymeric binder material that improves the structural integrity of the negative electrode 22. For example, the negative electrode 22 may contain more than or equal to about 10% by weight and less than or equal to about 99% by weight, and in some aspects, optionally more than or equal to about 60% by weight and less than or equal to about 99% by weight of the negatively active material; more than or equal to 0% by weight and less than or equal to about 40% by weight, and in some aspects, optionally more than or equal to about 0.5% by weight and less than or equal to about 20% by weight of the electronically conductive material; and more than or equal to 0% by weight and less than or equal to about 40% by weight, and in some aspects, optionally more than or equal to about 0.5% by weight and less than or equal to about 20% by weight of at least one polymeric binder.

[0072] Examples of polymeric adhesives include polyimide, polyamic acid, polyamide, polysulfone, polyvinylidene fluoride (PVdF) copolymer, polytetrafluoroethylene (PTFE), polyacrylic acid, blends of polyvinylidene fluoride and polyhexafluoropropylene, polychlorotrifluoroethylene, ethylene propylene diene monomer (EPDM), carboxymethyl cellulose (CMC), nitrile butadiene rubber (NBR), styrene-butadiene rubber (SBR), lithium polyacrylate (LiPAA), sodium polyacrylate (NaPAA), sodium alginate, and / or lithium alginate. Electronically conductive materials may include carbon-based materials, powdered nickel or other metal particles, or conductive polymers. Carbon-based materials may include, for example, graphite particles, acetylene black (e.g., KETCHEN). TM Black or Denka TMExamples of conductive polymers include polyaniline, polythiophene, polyacetylene, and polypyrrole. Examples of conductive polymers include polyaniline, polythiophene, polyacetylene, and polypyrrole.

[0073] The separator 26 may be a microporous polymer separator. The microporous polymer separator may include, for example, a polyolefin. The polyolefin may be a homopolymer (derived from a single monomer component) or a hybrid (derived from more than one monomer component), and may be linear or branched. If the hybrid is derived from two monomer components, the polyolefin may exhibit any copolymer chain arrangement, including those of block copolymers or random copolymers. Similarly, if the polyolefin is a hybrid derived from more than two monomer components, it may also be a block copolymer or a random copolymer. In some aspects, the polyolefin may be polyethylene (PE), polypropylene (PP), or a blend of polyethylene (PE) and polypropylene (PP), or a multilayer structured porous membrane of polyethylene (PE) and / or polypropylene (PP). Commercially available polyolefin porous membranes 26 include CELGARD. ® 2500 (single-layer polypropylene spacer) and CELGARD ® 2320 (Triple-layer polypropylene / polyethylene / polypropylene separator), available from Celgard LLC.

[0074] When the spacer 26 is a microporous polymer spacer, it can be a single layer or a multilayer composite, and can be manufactured by dry or wet processes. For example, in some cases, a single layer of polyolefin can form the entire spacer 26. In other aspects, the spacer 26 can be a fibrous membrane having a large number of pores extending between opposing surfaces and can have an average thickness of, for example, less than a millimeter. However, as another example, multiple discrete layers of similar or dissimilar polyolefins can be assembled to form the microporous polymer spacer 26. The spacer 26 may also include other polymers besides polyolefins, such as, but not limited to, polyethylene terephthalate (PET), polyvinylidene fluoride (PVdF), polyamides, polyimides, poly(amide-imide) copolymers, polyetherimides, and / or cellulose, or any other material suitable for producing the desired porous structure. The polyolefin layer and any other optional polymer layer may be further included as a fibrous layer in the spacer 26 to help provide suitable structural and porosity characteristics for the spacer 26.

[0075] Various conventionally available polymers and commercially available products for forming the spacer 26 are considered, as well as numerous manufacturing methods that can be used to prepare such a microporous polymer spacer 26. In each case, the spacer 26 may have an average thickness greater than or equal to about 1 μm to less than or equal to about 50 μm, and in some cases, optionally greater than or equal to about 1 μm to less than or equal to about 20 μm. Furthermore, in each variation, the spacer 26 may also comprise one or more ceramic materials and / or one or more heat-resistant materials. For example, the spacer 26 may also be mixed with one or more ceramic materials and / or one or more heat-resistant materials, or one or more surfaces of the spacer 26 may be coated with one or more ceramic materials and / or one or more heat-resistant materials. One or more ceramic materials may include, for example, alumina (Al2O3), silicon dioxide (SiO2), etc. Heat-resistant materials may include, for example, Nomex, aromatic polyamides, etc.

[0076] In all aspects, such as Figure 1 The porous separator 26 and / or the electrolyte 30 disposed in the porous separator 26 may be replaced by a solid electrolyte (“SSE”) layer and / or a semi-solid electrolyte (e.g., gel) layer serving as both the electrolyte and the separator. The solid electrolyte layer and / or semi-solid electrolyte layer may be disposed between the positive electrode 24 and the negative electrode 22. The solid electrolyte layer and / or semi-solid electrolyte layer facilitates lithium-ion transfer while mechanically separating and providing electrical insulation between the negative electrode 22 and the positive electrode 24. As a non-limiting example, the solid electrolyte layer and / or semi-solid electrolyte layer may comprise multiple solid electrolyte particles, such as LiTi2(PO4)3, LiGe2(PO4)3, Li7La3Zr2O. 12 Li 3x La 2 / 3-x TiO3, Li3PO4, Li3N, Li4GeS4, Li 10 GeP2S 12 , Li2S-P2S5, Li6PS5Cl, Li6PS5Br, Li6PS5I, Li3OCl, Li 2.99 Ba 0.005 O or combinations thereof. The solid electrolyte layer and / or semi-solid electrolyte layer may also include a gel polymer electrolyte (a polymer membrane having an absorbent liquid electrolyte). Examples of polymers include polyvinylidene fluoride, polyethylene glycol, polyacrylonitrile, poly(methyl methacrylate), copolymers thereof, or combinations thereof.

[0077] The positive electrode 24 may be formed of a lithium-based active material capable of lithium intercalation and deintercalation, alloying and dealloying, or plating and stripping, while serving as the positive terminal of the battery pack 20. The positive electrode 24 may be defined by a plurality of electroactive material particles. Such positive electroactive material particles may be disposed in one or more layers to define the three-dimensional structure of the positive electrode 24. For example, the positive electrode 24 may have a thickness greater than or equal to about 1 μm to less than or equal to about 500 μm, and in some aspects, optionally greater than or equal to about 10 μm to less than or equal to about 200 μm. The electrolyte 30 may be introduced, for example, after battery assembly and is contained within the pores of the positive electrode 24. For example, in some variations, the positive electrode 24 may comprise a plurality of solid electrolyte particles.

[0078] In various aspects, the positively charged active material can be an olivine compound (e.g., LiV2(PO4)3, LiFePO4, LiCoPO4, LiMn). x Fe 1-x PO4 (LMFP) (where 0.4 ≤ x ≤ 0.8), etc.; for example, the general formula is LiNi. x Mn y Co z Al (1-x-y-z) Layered oxides of O2 (where 0.33≤x≤0.96, 0.03≤y≤0.33, 0.005≤z≤0.33), LiNi x Mn y Co 1-x- y O2 (where 0.33 ≤ x ≤ 0.96 and 0.04 ≤ y ≤ 0.33) or LiNi x Mn 1-x O2 (where 0 ≤ x ≤ 1) and includes, for example, LiCoO2, LiNiO2, LiMnO2, LiNi 0.5 Mn 0.5 O2, LiNi 0.75 Mn 0.25 O2, NMC111, NMC523, NMC622, NMC721, NMC811, NCA, NCNMA, NMA, etc.; spinel compounds (e.g., LiMn2O4, LiNi 0.5 Mn 1.5 O4, etc.); lithium hydroxyphosphorus iron oxide compounds (e.g., LiVPO4F, etc.); borate compounds (e.g., LiFeBO3, LiCoBO3, LiMnBO3, etc.); silicate compounds (e.g., Li2FeSiO4, Li2MnSiO4, LiMnSiO4F, etc.); organic compounds (e.g., (2,5-dilithiumoxy)terephthalate, polyimide, etc.) and combinations thereof.

[0079] In various aspects, the positive electrode 24 is a capacitor auxiliary electrode comprising, for example, from about 0.1% by weight to less than or equal to about 80% by weight, and in some aspects, optionally from about 3% by weight to less than or equal to about 24% by weight, capacitor material. Although not shown, those skilled in the art will understand that in other variations, the negative electrode 22 may comprise capacitor material other than or in place of the positive electrode 24. Those skilled in the art will also understand that in some variations, the battery pack 20 may comprise capacitor layers other than or in place of the positive electrode 24 and / or the negative electrode 22.

[0080] In each variant, the capacitor material may be selected from the following: cobalt oxide (Co3O4), manganese oxide (MnO2), iridium oxide (IrO2), niobium pentoxide (Nb2O5), ruthenium oxide (RuO2), tantalum pentoxide (Ta2O5), tin oxide (SnO2), vanadium oxide (V2O5), titanium disulfide (TiS2), copper sulfide (CuS), iron sulfide (FeS), activated carbon (AC), graphene, graphite, mesoporous carbon, macroporous carbon, single-walled carbon nanotubes, multi-walled carbon nanotubes, carbon aerogel, activated carbon fiber cloth, polyaniline, polyacetylene, poly(3,4-ethylenedioxythiophene), poly(3,4-ethylenedioxythiophene), poly(4-styrene sulfonate / salt), and combinations thereof. Preferably, in some variants, the capacitor material may be selected from the following: activated carbon (AC), graphene, graphite, mesoporous carbon, macroporous carbon, single-walled carbon nanotubes, multi-walled carbon nanotubes, carbon aerogel, and combinations thereof. It is worth noting that, with positively charged active materials (e.g., approximately or less than 10 μm) 2 Compared to (g), capacitor materials have a relatively large surface area (e.g., greater than about 100m²). 2 / g, and in some respects, optionally about 1600m 2 / g).

[0081] In each variant, the positive electrode 24 may optionally be mixed (e.g., slurry casting) with one or more electronically conductive materials that provide an electronic conduction path and / or at least one polymeric binder material that improves the structural integrity of the positive electrode 24. For example, the positive electrode 24 may contain greater than or equal to about 10% by weight and less than or equal to about 99% by weight, and in some aspects, optionally greater than or equal to about 60% by weight and less than or equal to about 95% by weight of positively active material; greater than or equal to 0% by weight and less than or equal to about 40% by weight, and in some aspects, optionally greater than or equal to about 0.5% by weight and less than or equal to about 10% by weight of electronically conductive material; and greater than or equal to 0% by weight and less than or equal to about 40% by weight, and in some aspects, optionally greater than or equal to about 0.5% by weight and less than or equal to about 10% by weight of at least one polymeric binder.

[0082] The positive electrode 24, negative electrode 22, and separator 26 may each contain an electrolyte solution or system 30 within their pores, which is capable of conducting lithium ions between the negative electrode 22 and the positive electrode 24. Any suitable electrolyte 30, whether in solid, liquid, or gel form, capable of conducting lithium ions between the negative electrode 22 and the positive electrode 24, can be used in the lithium-ion battery pack 20. However, in each variant, the electrolyte 30 includes one or more electrolyte additives. For example, electrolyte 30 may include greater than or equal to about 0.1 wt% to less than or equal to about 5 wt%, greater than or equal to about 0.1 wt% to less than or equal to about 3 wt%, greater than or equal to about 0.1 wt% to less than or equal to about 1 wt%, and in some aspects, greater than or equal to about 0.1 wt% to less than or equal to about 0.5 wt% of a first electrolyte additive; and greater than or equal to about 0.1 wt% to less than or equal to about 5 wt%, greater than or equal to about 0.1 wt% to less than or equal to about 3 wt%, greater than or equal to about 0.1 wt% to less than or equal to about 1 wt%, and in some aspects, greater than or equal to about 0.1 wt% to less than or equal to about 0.5 wt% of a second electrolyte additive. The first electrolyte additive may include 3-trimethylsilylphenylboronic acid (TMSPB), and the second electrolyte additive may include succinic anhydride (SA).

[0083] One or more additives may be selected to improve the thermal tolerance of the capacitor-assisted battery pack 20. For example, one or more additives may help reduce or inhibit side reactions between active particles (including, for example, positively active material particles and capacitor additives) and electrolyte 30. For example, during the first or formation cycle and / or after cycling at high temperatures (e.g., about 55°C), the first and second additives may together form a first cathode electrolyte interface (CEI) layer or film 102 on the exposed surface of the positively active material 100 (e.g., as shown in the image). Figure 2A and 2B As shown), and a second cathode electrolyte interface layer 112 is formed on the exposed surface of the capacitor additive 110 (e.g., as shown). Figure 2B (As shown). Succinic anhydride contributes to the robustness of the first and second cathode electrolyte interface layers 102, 112, while 3-trimethylsilylphenylboronic acid, as a conductive material, reduces the impedance of the first and second cathode electrolyte interface layers.

[0084] like Figure 2AAs shown, the first cathode electrolyte interface layer 102 may substantially continuously cover, for example, greater than or equal to about 80%, optionally greater than or equal to about 85%, optionally greater than or equal to about 90%, optionally greater than or equal to about 95%, optionally greater than or equal to about 96%, optionally greater than or equal to about 97%, optionally greater than or equal to about 98%, optionally greater than or equal to about 99%, optionally greater than or equal to about 99.5%, and in some respects, optionally greater than or equal to about 99.8% of the total exposed surface area of ​​the positively active material 100. The first cathode electrolyte interface layer 102 may have an average thickness greater than or equal to about 1 nm to less than or equal to about 100 nm, and in some respects, optionally greater than or equal to about 1 nm to less than or equal to about 20 nm. Figure 2B This is a microscopic image of the first cathode electrolyte interface layer 102 on the exposed surface of the positively charged active material 100.

[0085] like Figure 3A As shown, due to the relatively large surface area and numerous functional groups of the capacitor additive, the second cathode electrolyte interface layer 112 can be a discontinuous coating with multiple pores 114. For example, the second cathode electrolyte interface layer 112 covers more than or equal to about 20% to less than or equal to about 80% of the total exposed surface area of ​​the capacitor additive 110. The discontinuous coating of the second cathode electrolyte interface layer 112 retains open sites for anion adsorption / desorption in order to maintain the pulse power capacity of the capacitor additive 110. The second cathode electrolyte interface layer 112 can have an average thickness of more than or equal to about 1 nm to less than or equal to about 500 nm, and in some aspects, optionally more than or equal to about 1 nm to less than or equal to about 100 nm. Figure 3B This is a microscopic image of the second cathode electrolyte interface 112 on the exposed surface of the capacitor additive 110. Figure 3B This is a microscopic image of the second cathode electrolyte interface layer 102 on the exposed surface of the capacitor additive 110.

[0086] Re-reference Figure 1 In some variations, electrolyte 30 may be a non-aqueous liquid electrolyte solution containing, in addition to one or more electrolyte additives, a lithium salt dissolved in an organic solvent or a mixture of organic solvents. Electrolyte 30 may have a salt concentration greater than or equal to about 0.6 M to less than or equal to about 2.0 M, and in some aspects, optionally about 1.0 M.

[0087] Non-limiting examples of lithium salts soluble in organic solvents to form non-aqueous liquid electrolyte solutions include lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4), lithium tetrachloroaluminate (LiAlCl4), lithium iodide (LiI), lithium bromide (LiBr), lithium thiocyanate (LiSCN), lithium tetrafluoroborate (LiBF4), lithium tetraphenylborate (LiB(C6H5)4), lithium bis(oxalate)borate (LiB(C2O4)2) (LiBOB), lithium difluorooxalate borate (LiBF2(C2O4)), lithium hexafluoroarsenate (LiAsF6), lithium trifluoromethanesulfonate (LiCF3SO3), lithium bis(trifluoromethane)sulfonylimide (LiN(CF3SO2)2), lithium bis(fluorosulfonylimide) (LiN(FSO2)2) (LiSFI), lithium bis(trifluoromethanesulfonylimide) (LiTFSI), and combinations thereof.

[0088] These and other similar lithium salts are soluble in a variety of non-aqueous, aprotic organic solvents, including but not limited to various alkyl carbonate esters, such as cyclic carbonates (e.g., ethylene carbonate (EC), propylene carbonate (PC), butyl carbonate (BC), fluoroethylene carbonate (FEC)), linear carbonates (e.g., dimethyl carbonate (DMC), diethyl carbonate (DEC), methyl ethyl carbonate (EMC)), aliphatic carboxylic acid esters (e.g., methyl formate, methyl acetate, methyl propionate), γ-lactones (e.g., γ-butyrolactone, γ-valerolactone), and combinations thereof. For example, in some variations, electrolyte 30 may comprise a mass ratio of approximately 3:5:2 of methyl ethyl carbonate (EMC): ethylene carbonate (EC): diethyl carbonate (DEC).

[0089] The following non-limiting embodiments further illustrate certain features of the prior art.

[0090] Example 1 The sample battery pack cells can be prepared according to various aspects of this disclosure.

[0091] For example, battery pack 410 may include an electrolyte having one or more additives, such as a first electrolyte additive comprising 3-trimethylsilylphenylboronic acid (TMSPB) and a second electrolyte additive comprising succinic anhydride (SA). Conversely, battery pack 420 may include a similar electrolyte, but omitting one or more additives.

[0092] Figure 4AThis is a diagram illustrating the cycle performance of the embodiment battery pack 410 at approximately 55°C, where the x-axis 400 represents the number of cycles and the y-axis 402 represents the capacity (mAh). As shown, the embodiment battery pack 410 exhibits improved performance compared to the comparative battery pack 420. In particular, the embodiment battery pack 410 shows approximately 70% improved capacity retention after 100 cycles at a 1C rate.

[0093] Figure 4B This is a diagram illustrating the cycle performance of the embodiment battery pack 410 at approximately 25°C, where the x-axis 450 represents the number of cycles and the y-axis 452 represents the capacity (mAh). As shown, the embodiment battery pack 410 exhibits improved performance compared to the comparative battery pack 420. In particular, the embodiment battery pack 410 shows approximately a 30% improvement in capacity retention after 500 cycles at 3C.

[0094] Figure 5A This is a diagram illustrating the self-discharge test of the embodiment battery pack 410 at approximately 25°C, where the x-axis 500 represents time (days) and the y-axis 502 represents voltage (V). As shown, the embodiment battery pack 410 maintains a stable and relatively high voltage for approximately forty days, which is attributed to the protective cathode electrolyte interface layer, and therefore improves performance (i.e., fewer side reactions) compared to the comparative battery pack 420.

[0095] Figure 5B This is a diagram illustrating the current response of the embodiment battery pack 410 at approximately 100% state of charge (SOC) and approximately 25°C, where the x-axis 550 represents time (hours) and the y-axis 552 represents current (mA). As shown, the embodiment battery pack 410 has an improved residual current, which is lower than that of the comparative battery pack 420. As those skilled in the art will recognize, lower residual current results in fewer side reactions.

[0096] Figure 5C This is a diagram illustrating the current response of the example battery pack 410 at approximately 100% state of charge (SOC) and approximately 55°C, where the x-axis 560 represents time (hours) and the y-axis 562 represents current (mA). As shown, the example battery pack 410 exhibits a significantly lower response current compared to the comparative battery pack 420.

[0097] For illustrative and descriptive purposes, the above description of the embodiments has been provided. It is not intended to be exhaustive or limiting of this disclosure. Various elements or features of a particular embodiment are generally not limited to that particular embodiment, but are interchangeable where applicable and can be used in selected embodiments, even if not specifically shown or described. The same can also be varied in many ways. Such variations should not be considered as departing from this disclosure, and all such modifications are intended to be included within the scope of this disclosure.

Claims

1. An electrolyte system for a capacitor-assisted battery pack, the electrolyte system comprising: Lithium-ion conducting components; A first additive comprising 0.1% by weight to 5% by weight, comprising 3-trimethylsilylphenylboronic acid; and A second additive containing succinic anhydride, greater than or equal to 0.1% by weight and less than or equal to 5% by weight.

2. The electrolyte system according to claim 1, wherein the lithium-ion conducting component is a lithium salt selected from the following: lithium hexafluorophosphate, lithium perchlorate, lithium tetrachloroaluminate, lithium iodide, lithium bromide, lithium thiocyanate, lithium tetrafluoroborate, lithium tetraphenylborate, lithium bis(oxalate)borate, lithium difluorooxalate borate, lithium hexafluoroarsenate, lithium trifluoromethanesulfonate, lithium bis(trifluoromethane)sulfonylimide, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, and combinations thereof.

3. The electrolyte system according to claim 2, wherein the electrolyte system has a lithium salt concentration of greater than or equal to 0.6 M and less than or equal to 2.0 M.

4. The electrolyte system according to claim 1, wherein the electrolyte system further comprises a solvent selected from the group consisting of ethylene carbonate, propylene carbonate, butyl carbonate, fluoroethylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, methyl formate, methyl acetate, methyl propionate, γ-butyrolactone, γ-valerolactone, and combinations thereof.

5. A capacitor-assisted battery pack, comprising: A capacitor auxiliary electrode, the capacitor auxiliary electrode comprising a capacitor material and an electroactive material for recycled lithium ions; as well as An electrolyte system comprising: Lithium-ion conducting components; 3-Trimethylsilylphenylboronic acid; and Succinic anhydride, 3-trimethylsilylphenylboronic acid, together with succinic anhydride (SA), defines a first coating on an electroactive material and a second coating on a capacitor material.

6. The capacitor-assisted battery pack according to claim 5, wherein the electrolyte system comprises 0.1% to 5% by weight of 3-trimethylsilylphenylboronic acid and 0.1% to 5% by weight of succinic anhydride.

7. The capacitor-assisted battery pack of claim 5, wherein the first coating is substantially continuous and covers more than or equal to 80% of the total exposed surface area of ​​the electroactive material.

8. The capacitor-assisted battery pack of claim 5, wherein the first coating has an average thickness of greater than or equal to 1 nm and less than or equal to 100 nm.

9. The capacitor-assisted battery pack according to claim 5, wherein the second coating is a discontinuous coating having a plurality of pores.

10. The capacitor-assisted battery pack of claim 9, wherein the second coating covers a total exposed surface area of ​​the capacitor material that is greater than or equal to 20% and less than or equal to 80%.

11. The capacitor-assisted battery pack of claim 5, wherein the second coating has an average thickness of greater than or equal to 1 nm and less than or equal to 500 nm.

12. The capacitor-assisted battery pack according to claim 5, wherein the lithium-ion conducting component is selected from the following lithium salts: lithium hexafluorophosphate, lithium perchlorate, lithium tetrachloroaluminate, lithium iodide, lithium bromide, lithium thiocyanate, lithium tetrafluoroborate, lithium tetraphenylborate, lithium bis(oxalate-based)borate, lithium difluorooxalate-based borate, lithium hexafluoroarsenate, lithium trifluoromethanesulfonate, lithium bis(trifluoromethane)sulfonylimide, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, and combinations thereof.

13. The capacitor-assisted battery pack of claim 12, wherein the electrolyte system has a lithium salt concentration of greater than or equal to 0.6 M and less than or equal to 2.0 M.

14. The capacitor-assisted battery pack according to claim 5, wherein the electrolyte system further comprises a solvent selected from the group consisting of ethylene carbonate, propylene carbonate, butyl carbonate, fluoroethylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, methyl formate, methyl acetate, methyl propionate, γ-butyrolactone, γ-valerolactone, and combinations thereof.

15. The capacitor-assisted battery pack according to claim 5, wherein the electroactive material is a positively active material.

16. The capacitor-assisted battery pack according to claim 15, wherein the positively active material is selected from: LiNi x Mn y Co z Al (1-x-y-z) O2, where 0.33≤x≤0.96, 0.03≤y≤0.33, 0.005≤z≤0.33, LiNi x Mn y Co 1-x-y O2, where 0.33 ≤ x ≤ 0.96, and 0.04 ≤ y ≤ 0.33, LiNi x Mn 1-x O2, where 0≤x≤1, and its combinations.

17. A capacitor-assisted battery pack, comprising: An electrolyte system comprising: Lithium-ion conducting components; The first additive contains 3-trimethylsilylphenylboronic acid; as well as A second additive containing succinic anhydride; as well as A capacitor auxiliary electrode, comprising: An electroactive material having a first coating defined thereon, the first coating being substantially continuous and covering more than or equal to 80% of the total exposed surface area of ​​the electroactive material, the first coating being defined by a first additive and a second additive. as well as A capacitor material having a second coating defined thereon, the second coating being a discontinuous coating covering more than or equal to 20% and less than or equal to 80% of the total exposed surface area of ​​the capacitor material, the second coating also being defined by the first additive and the second additive.

18. The capacitor-assisted battery pack of claim 17, wherein the electrolyte system comprises a first additive of greater than or equal to 0.1% by weight and less than or equal to 5% by weight, and A second additive of greater than or equal to 0.1% by weight and less than or equal to 5% by weight.

19. The capacitor-assisted battery pack of claim 17, wherein the lithium-ion conducting component comprises a lithium salt, and the electrolyte system has a lithium salt concentration of greater than or equal to 0.6 M and less than or equal to 2.0 M.

20. The capacitor-assisted battery pack of claim 17, wherein the first coating has an average thickness greater than or equal to 1 nm and less than or equal to 100 nm, and The second coating has an average thickness of greater than or equal to 1 nm and less than or equal to 500 nm.

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