Electrochemical exchange for manufacturing layered anode materials

Abstract

This disclosure discloses an electrochemical exchange method for manufacturing layered anode materials. The disclosure provides a method for forming a layered anode material. The method includes contacting a precursor material with a first electrolyte. The precursor material is a layered ionic compound represented by MX2, where M is one of calcium and magnesium, and X is one of silicon, germanium, and boron. The method further includes applying a first bias voltage and / or current while the precursor material is in contact with the first electrolyte to remove cations from the precursor material, thereby producing a two-dimensional structure defining the layered anode material. In some variations, the method further includes contacting the two-dimensional structure with a second electrolyte, and applying a second bias voltage and / or current while the two-dimensional structure is in contact with the second electrolyte to cause lithium ions to move into the interlayer spaces or voids created in the two-dimensional structure by removing cations, thereby forming the layered anode material.

Description

Technical Field

[0001] The present invention relates to a method for forming a layered anode material, a method for forming a layered anode material, and a method for forming a layered anode material. 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 various products, including automotive products such as start-stop systems (e.g., 12V start-stop systems), battery pack auxiliary systems, hybrid electric vehicles (“HEVs”), and electric vehicles (“EVs”). A typical lithium-ion battery pack includes at least two electrodes and an electrolyte and / or separator. One of the two electrodes can be used as a positive electrode or cathode, and the other electrode can be used as a negative electrode or anode. A separator filled with a liquid or solid electrolyte can be disposed between the negative and positive electrodes. The electrolyte is adapted to conduct lithium ions between the electrodes and, like the two electrodes, can be in solid and / or liquid form and / or a mixture thereof. In the case of solid-state battery packs that include solid electrodes and solid electrolytes (or solid separators), the solid electrolyte (or solid separator) can physically separate the electrodes, eliminating the need for separate separators.

[0004] Conventional rechargeable lithium-ion battery packs operate by reversibly transferring lithium ions back and forth between the negative and positive electrodes. For example, lithium ions can move from the positive to the negative electrode during charging and in the opposite direction during discharging. Such lithium-ion battery packs can reversibly supply power to associated load devices as needed. More specifically, power can be supplied to a load device by the lithium-ion battery pack until the lithium content at the negative electrode is effectively depleted. The battery pack can then be recharged by passing a suitable direct current in the opposite direction between the electrodes.

[0005] During discharge, the negative electrode may contain a relatively high concentration of intercalated lithium, which is oxidized into lithium ions and electrons. Lithium ions can move from the negative electrode to the positive electrode, for example, through an ion-conducting electrolyte solution contained within the pores of an inserted porous separator. Simultaneously, electrons travel from the negative electrode to the positive electrode via an external circuit. Such lithium ions can be absorbed into the positive electrode material through an electrochemical reduction reaction. The battery pack can be recharged or regenerated after its usable capacity has been partially or fully discharged by an external power source, reversing the electrochemical reactions that occurred during discharge.

[0006] Many different materials can be used to manufacture components for lithium-ion battery packs. For example, cathode materials used in lithium-ion battery packs typically include electroactive materials that can be intercalated with lithium ions, such as lithium transition metal oxides or mixed oxides, including LiMn2O4, LiCoO2, LiNiO2, and LiMn. 1.5 Ni 0.5 O4, LiNi (1-x-y) Co x M y O2 (where 0 < x < 1, y < 1, and M can be Al, Mn, etc.), or one or more phosphate compounds, such as lithium iron phosphate or mixed lithium manganese iron phosphate. The negative electrode typically includes a lithium intercalation material or an alloy host material. Typical electroactive materials used to form the anode include graphite and other forms of carbon, silicon and silicon oxide, tin and tin alloys.

[0007] Some anode materials possess particular advantages. Although the theoretical specific capacity is 372 mAh·g... -1 Graphite is most widely used in lithium-ion battery packs, but it has a high specific capacity, such as about 900 mAh·g. -1 Approximately 4,200 mAh·g -1 High specific capacity anode materials are attracting increasing attention. For example, silicon has the highest known theoretical lithium capacity (e.g., approximately 4,200 mAh·g). -1 Silicon is an attractive material for rechargeable lithium-ion battery packs. However, silicon-containing anodes suffer from drawbacks. For example, excessive volume expansion and contraction during continuous charge and discharge cycles (e.g., about 400% of silicon compared to about 10% of graphite). This volume change can lead to fatigue cracking and bursting of the electroactive material, as well as the fragmentation of material particles, which in turn can cause loss of electrical contact between the silicon-containing electroactive material and the rest of the battery pack, resulting in poor capacity retention and premature battery failure. This is especially true at the electrode loading levels required for the application of silicon-containing electrodes in high-energy lithium-ion battery packs, such as those used in transportation applications. Therefore, it is desirable to develop high-performance electrode materials that can address these challenges, particularly those containing silicon and other electroactive materials that undergo significant volume changes during lithium-ion cycling, as well as methods for preparing such high-performance electrode materials for use in high-energy and high-power lithium-ion battery packs. Summary of the Invention

[0008] This section provides a general overview of this disclosure and is not a full disclosure of its entire scope or all its features.

[0009] This disclosure relates to layered anode materials (e.g., two-dimensional (“2D”) layered silicon allotropes) and methods for forming them (e.g., electrochemical exchange manufacturing methods).

[0010] In various aspects, this disclosure provides a method for forming a layered anode material. The method may include removing cations from a precursor material using electrochemical extraction. The precursor material may be a layered ionic compound, and the removal of cations yields a two-dimensional structure defining the layered anode material.

[0011] In one respect, the precursor material can be represented by MX2, where M is one of calcium (Ca) and magnesium (Mg), and X is one of silicon (Si), germanium (Ge) and boron (B).

[0012] In one aspect, the precursor material may include alternating layers of M and X.

[0013] In one aspect, removing cations from a precursor material may include contacting the precursor material with an electrolyte and applying a bias voltage and / or current while the precursor material is in contact with the electrolyte.

[0014] In one aspect, the electrolyte may be a first electrolyte, the bias voltage and / or current may be a first bias voltage and / or current, the layered anode material may be a pre-lithiated anode material, and the method may further include a pre-lithiated two-dimensional structure. The pre-lithiated two-dimensional structure may include contacting the two-dimensional structure with a second electrolyte, and applying a second bias voltage and / or current when the two-dimensional structure contacts the second electrolyte, so as to allow lithium ions (Li...) to... + They move into the interlayer spaces or voids created by the removal of cations.

[0015] In one respect, the first electrolyte may be different from the second electrolyte, and the first bias voltage and / or current may be different from the second bias voltage and / or current.

[0016] In one respect, the second electrolyte may include a lithium source.

[0017] In one respect, electrolytes may include cation-compatible salts.

[0018] In one aspect, the precursor material may be disposed within and in contact with an electronically conductive liquid-permeable cage, and the electrolyte may include an electronically conductive liquid-permeable cage disposed within the electrolyte.

[0019] In one aspect, the electrolyte may be a first electrolyte, the bias voltage and / or current may be a first bias voltage and / or current, and after the first bias voltage and / or current is applied, the electronically conductive liquid-permeable cage may include a two-dimensional structure, the layered anode material may be a pre-lithiated anode material, and the method may further include the pre-lithiated two-dimensional structure. The pre-lithiated two-dimensional structure may include contacting the electronically conductive liquid-permeable cage comprising the two-dimensional structure with a second electrolyte, and applying a second bias voltage and / or current when the electronically conductive liquid-permeable cage comprising the two-dimensional structure contacts the second electrolyte to induce lithium ions (Li... + They move into the interlayer spaces or voids created by the removal of cations.

[0020] In one aspect, the precursor material may be disposed on the current collector, and contacting the precursor material with the electrolyte may include using one or more rollers to dispose of the precursor material and the current collector in the electrolyte.

[0021] In one aspect, the electrolyte may be a first electrolyte, the bias voltage and / or current may be a first bias voltage and / or current, and one or more rollers may be first rollers. After applying the first bias voltage and / or current, a two-dimensional structure may be disposed on the current collector. The layered anode material may be a pre-lithiated anode material, and the method may further include a pre-lithiated two-dimensional structure. The pre-lithiated two-dimensional structure may include using one or more second rollers to contact the two-dimensional structure and the current collector with a second electrolyte, and applying a second bias voltage and / or current while the two-dimensional structure and the current collector are in contact with the second electrolyte to facilitate movement and induce lithium ions (Li... + It enters the interlayer space or voids created by the removal of cations.

[0022] In various aspects, this disclosure provides a method for forming a layered anode material. The method may include removing cations from a precursor material using electrochemical extraction. The precursor material may be a layered ionic compound, and the removal of cations may produce a two-dimensional structure comprising multiple interlayer spaces or voids as a result of cation removal. The method may further include contacting the two-dimensional structure with an electrolyte and applying a bias voltage and / or current while the two-dimensional structure is in contact with the electrolyte to induce lithium ions (Li ions). + They move into the interlayer spaces or voids created by the removal of cations, thereby forming layered anode materials.

[0023] In one respect, the precursor material can be represented by MX2, where M is one of calcium (Ca) and magnesium (Mg), and X is one of silicon (Si), germanium (Ge) and boron (B).

[0024] In one aspect, the electrolyte may be a first electrolyte, the bias voltage and / or current may be a first bias voltage and / or current, and removing cations from the precursor material may include contacting the precursor material with a second electrolyte, and applying a second bias voltage and / or current while the precursor material is in contact with the second electrolyte.

[0025] In one aspect, the precursor material may be disposed in an electronically conductive liquid-permeable cage, and contacting the precursor material with the second electrolyte may include disposing the electronically conductive liquid-permeable cage in the second electrolyte, such that contacting the two-dimensional structure with the first electrolyte includes subsequently disposing the electronically conductive liquid-permeable cage in the first electrolyte.

[0026] In one aspect, a precursor material may be disposed on a current collector, and contacting the precursor material and the second electrolyte may include disposing the precursor material and the current collector in the second electrolyte using one or more first rollers, and contacting the two-dimensional structure and the first electrolyte may include using one or more second rollers to subsequently dispose the two-dimensional structure and the current collector in the first electrolyte.

[0027] In various aspects, this disclosure provides a method for forming a layered anode material. The method may include contacting a precursor material with a first electrolyte. The precursor material may be a layered ionic compound represented by MX2, where M is one of calcium (Ca) and magnesium (Mg), and X is one of silicon (Si), germanium (Ge), and boron (B). The method may further include applying a first bias voltage and / or current while the precursor material is contacted with the first electrolyte to remove cations from the precursor material, producing a two-dimensional structure comprising a plurality of interlayer spaces or voids created by the removal of cations. The method may also include contacting the two-dimensional structure with a second electrolyte, and applying a second bias voltage and / or current while the two-dimensional structure is contacted with the second electrolyte to allow lithium ions (Li...) to... + They move into the interlayer spaces or voids created by the removal of cations, thereby forming layered anode materials.

[0028] In one aspect, the precursor material may be disposed in an electronically conductive liquid-permeable cage, and contacting the precursor material with a first electrolyte may include disposing the electronically conductive liquid-permeable cage in the first electrolyte, such that contacting the two-dimensional structure with a second electrolyte includes subsequently disposing the electronically conductive liquid-permeable cage in the second electrolyte.

[0029] In one aspect, the precursor material may be disposed on the current collector, and contacting the precursor material with the first electrolyte may include using one or more rollers to dispose the precursor material and the current collector in the first electrolyte, and contacting the two-dimensional structure with the second electrolyte may include using one or more second rollers to subsequently dispose the two-dimensional structure and the current collector in the second electrolyte.

[0030] The present invention discloses the following embodiments:

[0031] 1. A method for forming a layered anode material, the method comprising:

[0032] The cations are removed from a precursor material, which is a layered ionic compound, using electrochemical extraction, and the removal of the cations produces a two-dimensional structure that defines a layered anode material.

[0033] 2. According to the method of embodiment 1, the precursor material is represented by MX2, where M is one of calcium (Ca) and magnesium (Mg), and X is one of silicon (Si), germanium (Ge) and boron (B).

[0034] 3. The method according to embodiment 2, wherein the precursor material comprises alternating layers of M and X.

[0035] 4. The method according to embodiment 1, wherein removing cations from the precursor material comprises:

[0036] Contact the precursor material with the electrolyte, and

[0037] When the precursor material comes into contact with the electrolyte, a bias voltage and / or current are applied.

[0038] 5. The method according to embodiment 4, wherein the electrolyte is a first electrolyte, the bias voltage and / or current is a first bias voltage and / or current, the layered anode material is a pre-lithiated anode material, and the method further includes pre-lithiating the two-dimensional structure, wherein pre-lithiating the two-dimensional structure includes:

[0039] To bring the two-dimensional structure into contact with the second electrolyte, and

[0040] When the two-dimensional structure contacts the second electrolyte, a second bias voltage and / or current is applied to enable lithium ions (Li...) + They move into the interlayer spaces or voids created by the removal of cations.

[0041] 6. According to the method of embodiment 5, wherein the first electrolyte is different from the second electrolyte, and the first bias voltage and / or current is different from the second bias voltage and / or current.

[0042] 7. The method according to embodiment 5, wherein the second electrolyte comprises a lithium source.

[0043] 8. The method according to embodiment 4, wherein the electrolyte comprises a cation-compatible salt.

[0044] 9. The method according to embodiment 4, wherein the precursor material is disposed in an electronically conductive liquid-permeable cage, and contacting the precursor material with the electrolyte comprises disposing the electronically conductive liquid-permeable cage in the electrolyte.

[0045] 10. The method according to embodiment 9, wherein the electrolyte is a first electrolyte, the bias voltage and / or current is a first bias voltage and / or current, after the first bias voltage and / or current is applied, the electronically conductive liquid-permeable cage comprises a two-dimensional structure, and the layered anode material is a pre-lithiated anode material, and

[0046] The methods also include:

[0047] Pre-lithiation of the two-dimensional structure, wherein pre-lithiation of the two-dimensional structure includes contacting a liquid-permeable cage containing the electronically conductive two-dimensional structure with a second electrolyte, and

[0048] When a liquid-permeable cage comprising an electronically conductive two-dimensional structure contacts a second electrolyte, a second bias voltage and / or current are applied to induce lithium ions (Li... + They move into the interlayer spaces or voids created by the removal of cations.

[0049] 11. According to the method of embodiment 4, wherein the precursor material is disposed on the current collector and the precursor material is contacted with the electrolyte comprises disposing the precursor material and the current collector in the electrolyte using one or more rollers.

[0050] 12. The method according to embodiment 11, wherein the electrolyte is a first electrolyte, the bias voltage and / or current is a first bias voltage and / or current, the one or more rollers are first rollers, a two-dimensional structure is disposed on the current collector after applying the first bias voltage and / or current, and the layered anode material is a pre-lithiated anode material, and

[0051] The methods also include:

[0052] Pre-lithiation of the two-dimensional structure, wherein pre-lithiation of the two-dimensional structure includes using one or more second rollers to contact the two-dimensional structure and the current collector with a second electrolyte, and

[0053] While the two-dimensional structure and the current collector are in contact with the second electrolyte, a second bias voltage and / or current are applied to induce movement of lithium ions (Li...). + It enters the interlayer space or voids created by the removal of cations.

[0054] 13 A method for forming a layered anode material, the method comprising:

[0055] Electrochemical extraction is used to remove cations from a precursor material, wherein the precursor material is a layered ionic compound, and the removal of cations produces a two-dimensional structure comprising multiple interlayer spaces or voids created by the removal of cations.

[0056] To bring the two-dimensional structure into contact with the electrolyte; and

[0057] When a two-dimensional structure contacts an electrolyte, a bias voltage and / or current are applied to induce lithium ions (Li... + They move into the interlayer spaces or voids created by the removal of cations, thereby forming layered anode materials.

[0058] 14. According to the method of embodiment 13, the precursor material is represented by MX2, wherein M is one of calcium (Ca) and magnesium (Mg), and X is one of silicon (Si), germanium (Ge) and boron (B).

[0059] 15. The method according to embodiment 13, wherein the electrolyte is a first electrolyte, and the bias voltage and / or current is a first bias voltage and / or current, and wherein removing the cations from the precursor material comprises:

[0060] Contact the precursor material with the second electrolyte, and

[0061] When the precursor material comes into contact with the second electrolyte, a second bias voltage and / or current is applied.

[0062] 16. The method according to embodiment 15, wherein the precursor material is disposed in an electronically conductive liquid-permeable cage, and contacting the precursor material with the second electrolyte comprises disposing the electronically conductive liquid-permeable cage within the second electrolyte, and

[0063] Contacting the two-dimensional structure with the first electrolyte includes subsequently placing an electronically conductive liquid-permeable cage within the first electrolyte.

[0064] 17. According to the method of embodiment 15, wherein the precursor material is disposed on the current collector, and contacting the precursor material with the second electrolyte comprises using one or more first rollers to dispose of the precursor material and the current collector in the second electrolyte, and

[0065] Contacting the two-dimensional structure with the first electrolyte includes using one or more second rollers to subsequently place the two-dimensional structure and the current collector in the first electrolyte.

[0066] 18. A method for forming a layered anode material, the method comprising:

[0067] The precursor material is brought into contact with a first electrolyte, wherein the precursor material is a layered ionic compound represented by MX2, wherein M is one of calcium (Ca) and magnesium (Mg), and X is one of silicon (Si), germanium (Ge) and boron (B);

[0068] When the precursor material comes into contact with the first electrolyte, a first bias voltage and / or current are applied to remove cations from the precursor material to produce a two-dimensional structure comprising a plurality of interlayer spaces or voids created by removing cations.

[0069] To bring the two-dimensional structure into contact with the second electrolyte; and

[0070] When the two-dimensional structure contacts the second electrolyte, a second bias voltage and / or current is applied to induce lithium ions (Li... + They move into the interlayer spaces or voids created by the removal of cations, thereby forming layered anode materials.

[0071] 19. According to the method of embodiment 18, wherein the precursor material is disposed in an electronically conductive liquid-permeable cage, and contacting the precursor material with the first electrolyte includes disposing the electronically conductive liquid-permeable cage in the first electrolyte, and contacting the two-dimensional structure with the second electrolyte includes subsequently disposing the electronically conductive liquid-permeable cage in the second electrolyte.

[0072] 20. The method according to embodiment 15, wherein the precursor material is disposed on the current collector, and contacting the precursor material with the first electrolyte comprises using one or more rollers to dispose of the precursor material and the current collector in the first electrolyte, and

[0073] Contacting the two-dimensional structure with the second electrolyte includes using one or more second rollers to subsequently place the two-dimensional structure and the current collector in the second electrolyte.

[0074] Further areas of application will become apparent from the description provided herein. The descriptions and specific examples in this invention are for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0075] 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.

[0076] Figure 1 This is a schematic diagram of an exemplary electrochemical battery pack including layered electroactive materials according to various aspects of this disclosure;

[0077] Figure 2This illustrates aspects of the present disclosure for use in manufacturing electrochemical battery packs (such as...). Figure 1 A flowchart of an exemplary method for using layered electroactive materials in an exemplary electrochemical battery pack (as shown in the illustration) and pre-lithiating the layered electroactive materials;

[0078] Figure 3A This disclosure illustrates various aspects of the manufacture of batteries in electrochemical battery packs (such as...). Figure 1 The electrochemical exchange method of the layered electroactive material used in the exemplary electrochemical battery pack shown in the figure;

[0079] Figure 3B This disclosure illustrates methods for making layered electroactive materials (such as...) according to various aspects of the present disclosure. Figure 3A The electrochemical exchange method for pre-lithiation of layered electroactive materials (shown in the figure);

[0080] Figure 4 The present disclosure illustrates various aspects of the method for forming cells in electrochemical cell arrays (such as...). Figure 1 An exemplary roll-to-roll method for using pre-lithiated layered electroactive materials in an exemplary electrochemical battery pack (as shown in the diagram), and

[0081] Figure 5 The present disclosure illustrates various aspects of forming a cell for an electrochemical battery pack (such as...). Figure 1 An exemplary continuous method for pre-lithiated layered electroactive materials in an exemplary electrochemical battery pack (shown in the figure).

[0082] In the various views of the accompanying drawings, the corresponding reference numerals denote the respective components. Detailed Implementation

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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 that the numerical value allows for a certain degree of slight imprecision (approaching the exact value to a certain extent; substantially or reasonably approximating the value; almost). If the imprecision provided by “about” is not otherwise understood in this ordinary sense in the art, then “about” as used herein refers to at least a deviation that can be caused by ordinary 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%.

[0090] 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.

[0091] Exemplary embodiments will now be described more fully with reference to the accompanying drawings.

[0092] This disclosure relates to layered anode materials for electrochemical cells used in cycling lithium-ion batteries, and methods for forming the same. The layered anode material may be a two-dimensional (“2D”) layered silicon allotrope, and in some variations, the layered anode material may be pre-lithiated. Methods for forming the layered anode material may include removing cations from a precursor material using an electrochemical exchange method. The precursor material may be an ionic compound (e.g., represented by MX2, where M is one of calcium (Ca) and magnesium (Mg), and X is one of silicon (Si), germanium (Ge), and / or boron (B)) comprising alternating layers such that cations (e.g., Ca...)... 2+ It is easily extracted electrochemically. For example, precursor materials may include CaSi2, which is a compound comprising alternating layers of silicon and calcium. When removing cations (e.g., Ca...) 2+ When lithium ions (Li) are exchanged, a two-dimensional layered crystal structure remains. In some variations, lithium ions (Li) can be exchanged using an electrochemical exchange method. + The layered anode material is pre-lithiated by moving into the interlayer space or voids created by removing cations.

[0093] 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 (or sodium ions in the case of a sodium-ion battery pack, etc.) and can be in liquid, gel, or solid form. For example, Figure 1 An exemplary and schematic illustration of an electrochemical cell (also known as a battery pack) 20 is shown.

[0094] This type of battery is used in vehicle or automotive transportation applications (e.g., motorcycles, boats, tractors, buses, motorbikes, 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, devices, buildings (e.g., houses, offices, sheds, and warehouses), office equipment and furniture, as well as industrial equipment machinery, agricultural or farm equipment, or heavy machinery, as non-limiting examples. Furthermore, although the examples shown include a single positive cathode and a single anode, those skilled in the art will recognize that this teaching extends to a variety of other constructions, including those having one or more cathodes and one or more anodes, and various current collectors having an electroactive layer disposed on or adjacent to one or more of their surfaces.

[0095] 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 between the electrodes 22, 24, preventing physical contact. The separator 26 also provides a minimized resistance path for the interior of lithium ions (and in some cases, associated anions) during lithium-ion cycling. In various aspects, the separator 26 includes an electrolyte 30, which may also be present in both 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. For example, the separator 26 may be defined by a plurality of solid electrolyte particles (not shown).

[0096] The negative current collector 32 may be located at or near the negative electrode 22. The negative current collector 32 may be a metal foil, metal grid or screen, or porous metal containing copper or any other suitable conductive material known to those skilled in the art. The positive current collector 34 may be located at or near the positive electrode 24. The positive current collector 34 may be a metal foil, metal grid or screen, or porous metal containing aluminum or any other suitable conductive material known to those skilled in the art. The negative current collector 32 and the positive current collector 34 collect and move free electrons to the external circuit 40 and are respectively collected and moved by the external circuit 40. For example, the interruptible external circuit 40 and the load device 42 may be connected to the negative electrode 22 (through the negative current collector 32) and the positive electrode 24 (through the positive current collector 34).

[0097] 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 chemical 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) through external circuit 40 to positive electrode 24. Lithium ions also generated at negative electrode 22 simultaneously transfer through electrolyte 30 contained in separator 26 to positive electrode 24. 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.

[0098] 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 reactions 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 across the separator 26 to 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 grid via a wall power outlet.

[0099] In many lithium-ion battery pack configurations, each of the negative current collector 32, negative electrode 22, separator 26, positive electrode 24, and positive current collector 34 is fabricated as a relatively thin layer (e.g., from a few micrometers to a fraction of a millimeter or less) and mounted in electrically parallel arrangement to provide suitable energy and power encapsulation. In various aspects, the battery pack 20 may also include a variety of other components, although not shown herein, but known to those skilled in the art. For example, the battery pack 20 may include a housing, gaskets, terminal caps, tabs, battery pack terminals, and any other conventional components or materials that may be located within the battery pack 20, including between or around the negative electrode 22, positive electrode 24, and / or separator 26. Figure 1 The battery pack 20 shown includes a liquid electrolyte 30 and illustrates a representative concept of battery pack operation. However, this technology is also applicable to solid-state battery packs that include solid-state electrolytes and / or solid electroactive particles, which may have different designs known to those skilled in the art.

[0100] As described above, the size and shape of the battery pack 20 can vary depending on the specific application it is designed for. 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 also be connected in series or parallel with other similar lithium-ion batteries or battery packs to generate greater voltage output, energy, and power, if required by the load device 42. 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.

[0101] Refer again Figure 1 The positive electrode 24, negative electrode 22, and separator 26 may each include an electrolyte solution or system 30 within its pores, which is capable of conducting lithium ions between the negative electrode 22 and the positive electrode 24. Any suitable electrolyte 30 capable of conducting lithium ions between the negative electrode 22 and the positive electrode 24, whether in solid, liquid, or gel form, can be used in the lithium-ion battery pack 20. In some aspects, the electrolyte 30 may be a non-aqueous liquid electrolyte solution containing a lithium salt dissolved in an organic solvent or a mixture of organic solvents. Many conventional non-aqueous liquid electrolyte solutions 30 can be used in the lithium-ion battery pack 20.

[0102] In some respects, electrolyte 30 may be a non-aqueous liquid electrolyte solution comprising one or more lithium salts dissolved in an organic solvent or a mixture of organic solvents. For example, a non-limiting list of lithium salts that can be dissolved in organic solvents to form non-aqueous liquid electrolyte solutions includes 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), and combinations thereof.

[0103] These and other similar lithium salts are soluble in a variety of non-aqueous, aprotic organic solvents, including but not limited to various alkyl carbonates, such as cyclic carbonates (e.g., ethylene carbonate (EC), propylene carbonate (PC), butene carbonate (BC), fluoroethylene carbonate (FEC)), linear carbonates (e.g., dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC)), aliphatic carboxylic acid esters (e.g., methyl formate, methyl acetate, methyl propionate), γ-lactones (e.g., γ-butyrolactone, γ-valerolactone), chain ethers (e.g., 1,2-dimethoxyethane, 1,2-diethoxyethane, ethoxymethoxyethane), cyclic ethers (e.g., tetrahydrofuran, 2-methyltetrahydrofuran), 1,3-dioxolane), sulfur-containing compounds (e.g., sulfolane), and combinations thereof.

[0104] In some cases, the porous separator 26 may comprise a microporous polymer separator containing 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 take 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 PE and PP, or a multilayer structured porous membrane of PE and / or PP. Commercially available polyolefin porous separator membranes 26 include CELGARD. ® 2500 (single-layer polypropylene separator membrane) and CELGARD ® 2320 (Triple-layer polypropylene / polyethylene / polypropylene separator film) is available from Celgard LLC.

[0105] In some respects, the spacer 26 may also include one or more of a ceramic coating and a heat-resistant material coating. The ceramic coating and / or the heat-resistant material coating may be disposed on one or more sides of the spacer 26. The material forming the ceramic layer may be selected from: alumina (Al2O3), silicon dioxide (SiO2), and combinations thereof. The heat-resistant material may be selected from: Nomex, aramid, and combinations thereof.

[0106] When the spacer 26 is a microporous polymer spacer, it can be a single layer or a multilayer composite, and it 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. In some respects, the spacer 26 may also be mixed with a ceramic material, or its surface may be coated with a ceramic material. For example, the ceramic coating may include alumina (Al2O3), silicon dioxide (SiO2), titanium dioxide (TiO2), or a combination thereof. Various conventionally available polymers and commercial products for forming the spacer 26 are considered, as well as many manufacturing methods that can be used to produce such a microporous polymer spacer 26.

[0107] In all aspects, Figure 1 The porous separator 26 and electrolyte 30 can be replaced by a solid electrolyte (“SSE”) (not shown) serving as both the electrolyte and separator. The solid electrolyte can be disposed between the positive electrode 24 and the negative electrode 22. The solid electrolyte 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 may include LiTi2(PO4)3, LiGe2(PO4)3, or 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 ClO or combinations thereof.

[0108] The positive electrode 24 may be formed of a lithium-based active material (or a sodium-based active material in the case of a sodium-ion battery pack), which is capable of lithium intercalation and deintercalation, alloying and dealloying, or plating and stripping, and serves as the positive terminal of the battery pack 20. The positive electrode 24 may be defined by a plurality of electroactive material particles (not shown) disposed in one or more layers to define the three-dimensional structure of the positive electrode 24. An electrolyte 30 may be incorporated, for example, after battery assembly and contained within pores (not shown) of the positive electrode 24. For example, the positive electrode 24 may comprise a plurality of electrolyte particles (not shown).

[0109] A typical and common category of known materials that can be used to form the cathode 24 is layered lithium transition metal oxides. For example, in some aspects, the cathode 24 may comprise one or more materials having a spinel structure, such as lithium manganese oxide (Li). (1+x) Mn₂O₄, where 0.1≤x≤1), lithium manganese nickel oxide (LiMn (2-x) Ni x O4, where 0 ≤ x ≤ 0.5 (e.g., LiMn) 1.5 Ni 0.5 O4); one or more materials with a layered structure, such as lithium cobalt oxide (LiCoO2), lithium nickel manganese cobalt oxide (Li(Ni)O2), etc. x Mn y Co z O2, where 0≤x≤1, 0≤y≤1, 0≤z≤1, and x+y+z=1 (e.g., LiMn) 0.33 Ni 0.33 Co 0.33 O2) or lithium nickel cobalt metal oxide (LiNi (1-x-y) Co x M y O2, where 0 < x < 0.2, y < 0.2, and M can be Al, Mg, Ti, etc.; or lithium iron polyanionic oxides with an olivine structure, such as lithium iron phosphate (LiFePO4) and lithium manganese iron phosphate (LiMn). 2-x Fe x PO4, where 0 < x < 0.3) or lithium iron fluorophosphate (Li2FePO4F).

[0110] In some variations, the positively active material may optionally be mixed with an electronically conductive material that provides an electron conduction path and / or at least one polymeric binder material that improves the structural integrity of the electrode. For example, the positively active material and the electronically or conductive material may be cast using a binder such as polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), ethylene propylene diene monomer (EPDM) or carboxymethyl cellulose (CMC), nitrile butadiene rubber (NBR), styrene-butadiene rubber (SBR), lithium polyacrylate (LiPAA), sodium polyacrylate (NaPAA), sodium alginate, or lithium alginate. The conductive material may include carbon-based materials, powdered nickel or other metal particles, or conductive polymers. Carbon-based materials may include, for example, graphite, acetylene black (e.g., KETJEN). TM Black or Denka TM Particles such as black carbon fibers and nanotubes, graphene, etc. Examples of conductive polymers include polyaniline, polythiophene, polyacetylene, polypyrrole, etc. In some applications, mixtures of conductive materials may be used.

[0111] The positive electrode 24 may comprise more than or equal to about 80% by weight and less than or equal to about 99% by weight of positively active material, more than or equal to about 0% by weight and less than or equal to about 15% by weight of electronically conductive material, and more than or equal to about 0% by weight and less than or equal to about 15% by weight, and in some aspects optionally more than or equal to about 0% by weight and less than or equal to about 15% by weight of at least one polymer binder.

[0112] The negative electrode 22 contains a lithium host material that can be used as the negative terminal of a lithium-ion battery pack. For example, the negative electrode 22 may contain a lithium host material (e.g., a negatively active material) that can be used 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 (not shown). Such negatively active material particles may be disposed in one or more layers to define the three-dimensional structure of the negative electrode 22. The electrolyte 30 may be incorporated, for example, after battery assembly and housed within pores (not shown) of the negative electrode 22. For example, the negative electrode 22 may include a plurality of electrolyte particles (not shown).

[0113] The negative electrode 22 comprises an electroactive material that serves as the host lithium material for use as the negative terminal of a lithium-ion battery pack. The electroactive material comprises an atomically layered anode material, wherein each crystalline plane is considered layered. The atomically layered anode material may include silicon (Si), germanium (Ge), and / or boron (B). For example, the electroactive material may include a two-dimensional layered allotrope of silicon (Si), germanium (Ge), and / or boron (B), comprising planes of atoms strongly bonded in-plane and weakly coupled out-of-plane (i.e., little to no bonding between layers) at the angstrom scale, similar to graphite. In other words, the atomically layered anode material may include silicene, multilayered silicene, germanene, multilayered germanene, boronene, multilayered boronene, or any combination thereof. The atomically layered anode material can be formed into micron / nanometer-scale electroactive particles, for example, electroactive material particles with an average diameter greater than or equal to about 100 nm to less than or equal to about 50 μm.

[0114] This electroactive material exhibits improved cycleability; for example, it can possess an intrinsic capacity of approximately 2,000 mAh / g at a current of approximately 100 mA / g. The layered structure serves to release internal stresses generated during lithiation and enhance ion diffusion within the anode 22. For example, as described below, the two-dimensional structure allows lithium to be embedded between layers through pseudo van der Waals gaps to store lithium without disrupting the lattice structure, thus avoiding structural fragmentation or bursting (similar to lithium embedding in graphite). Furthermore, the two-dimensional channels formed between the layers can better facilitate ion diffusion, allowing for faster charging rates.

[0115] In various aspects, the negatively active material can be a composite material comprising (e.g., in the form of a first plurality of electroactive material particles) a layered anode material (e.g., silicene, germanene, and / or boronene) and (e.g., in the form of a second plurality of electroactive material particles) another negatively active material (e.g., graphite, graphene, carbon nanotubes, carbon nanofibers, carbon black, or any combination thereof). For example, the composite material may contain greater than or equal to about 5% by weight and less than or equal to about 95% by weight of the layered anode material, and greater than or equal to about 5% by weight and less than or equal to about 95% by weight of other negatively active materials.

[0116] In a further variation, the negatively charged active material can include two-dimensional layered allotropes (e.g., two-dimensional layered silicon allotropes, for example, in the form of a first plurality of electroactive material particles) and three-dimensional allotropes (e.g., three-dimensional layered silicon allotropes, such as SiO₂). x and Li x SiO xThe composite material is a combination of two-dimensional layered silicon allotropes, wherein the three-dimensional allotropes are, for example, in the form of a second plurality of electroactive material particles. For example, the composite material may contain greater than or equal to about 5% by weight and less than or equal to about 95% by weight of two-dimensional layered silicon allotropes, and greater than or equal to about 5% by weight and less than or equal to about 95% by weight of three-dimensional silicon allotropes.

[0117] In each case, the negatively active material may be pre-lithiated before (i.e., out-of-situ) or after (i.e., in-situ) its incorporation into the negative electrode 22 and / or battery pack 20 to compensate for lithium loss during cycling, for example, said lithium loss may occur during the conversion reaction and / or on the negative electrode 22 during the first cycle. x Lithium loss occurs during the formation of Si and / or solid electrolyte interphase (SEI) layers (not shown), and also due to, for example, the formation of continuous solid electrolyte interphase (SEI).

[0118] In some variations, the layered anode material may optionally be mixed with one or more conductive materials that provide electron conduction pathways and / or at least one polymeric binder material that improves the structural integrity of the negative electrode 22. For example, the negatively active material in the negative electrode 22 may optionally be mixed with a binder such as polyimide, polyamic acid, polyamide, polysulfone, polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), ethylene propylene diene monomer (EPDM) rubber or carboxymethyl cellulose (CMC), nitrile butadiene rubber (NBR), styrene-butadiene rubber (SBR), lithium polyacrylate (LiPAA), sodium polyacrylate (NaPAA), sodium alginate, or lithium alginate. The conductive material may include carbon-based materials, powdered nickel or other metal particles, or conductive polymers. Carbon-based materials may include, for example, graphite, acetylene black (e.g., KETJEN). TM Black or Denka TM Particles such as black carbon fibers and nanotubes, graphene, etc. Examples of conductive polymers include polyaniline, polythiophene, polyacetylene, polypyrrole, etc. In some applications, mixtures of conductive materials may be used.

[0119] The negative electrode 22 may comprise more than or equal to about 10 wt.% to less than or equal to about 99 wt.% of a layered anode material, more than or equal to about 0 wt.% to less than or equal to about 20 wt.% of an electronically conductive material, and more than or equal to about 0 wt.% to less than or equal to about 20 wt.%, and in some aspects optionally more than or equal to about 1 wt.% to less than or equal to about 20 wt.%.

[0120] In various aspects, this disclosure provides preparation for anodes (e.g. Figure 1The method for preparing a layered anode material (e.g., a two-dimensional layered silicon allotrope) for the negative electrode 22 shown herein. For example, this disclosure contemplates a method for preparing a layered anode material using an electrochemical exchange method. The method typically includes removing cations from a precursor material using a first bias voltage and / or current to form a two-dimensional layered crystal. In some variations, the method may also include pre-lithiating the two-dimensional layered anode material, for example, by applying a second bias voltage and / or current to a lithium source. In each case, the method may be performed using either an intermittent method or a continuous method (e.g., a roll-to-roll method), by way of example only.

[0121] Figure 2 An exemplary method 200 for forming a layered anode material is shown. Method 200 includes removing 230 cations from a precursor material using a temperature-controlled method. For example, substantially all of the 230 cations may be removed from the precursor material, or in some variations, 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%, or optionally greater than or equal to about 99.5% of the cations. The precursor material may be an ionic compound represented by MX2, where M is one of calcium (Ca) and magnesium (Mg), and X is one of silicon (Si), germanium (Ge), and / or boron (B). In each case, the precursor material comprises alternating layers such that cations (e.g., Ca...) are removed from the precursor material. 2+ It is easily extracted electrochemically. For example, precursor materials may include CaSi2, which is a compound comprising alternating atomic layers of silicon and calcium. When removing cations (e.g., Ca...) 2+ When ), two-dimensional layered crystals are left behind.

[0122] Electrochemical exchange methods can be used to remove 230 cations. For example, such as... Figure 3A As shown, the precursor material 310 may be disposed in the first current collector 332 (e.g., similar to...). Figure 1 The first current collector 332 may be on or near the surface of the second current collector 334 (e.g., similar to the negative current collector 334). Figure 1 The positive current collector 34 shown is aligned with the positive current collector 332, and a first bias voltage (i.e., voltage) and / or current can be applied to induce cations 350 to move from the precursor material 300 to the second current collector 334, thereby leaving a two-dimensional layered anode material 312 on or near the first current collector 332, which, in some variations, can be disposed as a negatively charged active material in the battery (e.g., as shown in the diagram). Figure 1 In the battery pack 20 shown.

[0123] A first current collector 332, a precursor material 310, and a second current collector are disposed in a first electrolyte solution. For example, in an exemplary intermittent method, the first current collector 332 and the precursor material 310 may be disposed in an electronically conductive liquid-permeable cage, which is placed in the first electrolyte bath before a first bias voltage and / or current is applied. The electronically conductive liquid-permeable cage is configured to hold or fix the precursor material 310, but allows cations to flow or move in and out of the electronically conductive liquid-permeable cage.

[0124] In each case, the first electrolyte solution may include a cation-compatible salt in a solvent solution, which dissolves (e.g., solvates) the cation and the cation-compatible salt. For example, when the prebody material contains calcium, the first electrolyte solution may contain 1M calcium tetrafluoroborate hydrate (Ca(BF4)2) in a solvent ethylene carbonate (EC):propylene carbonate (PC) (1:1). When the prebody material 310 includes CaSi2, the electrochemical exchange can be summarized as follows: (1) Anode: xCaSi2 xCa 2+ +2xe - +2D-Si and (2) cathode: Ca 2+ +2e - Ca.

[0125] Re-reference Figure 2 In some variations, as shown in the figure, method 200 may include obtaining or preparing a precursor material 210, and setting the precursor material 220 on or near one or more surfaces of the current collector. For example, preparing the precursor material 210 may include milling the precursor material to reduce the particle size (e.g., to an average particle diameter greater than or equal to about 100 nm to less than or equal to about 50 μm) and increase the surface area, thereby reducing the cation exchange time and increasing the likelihood of producing a uniform two-dimensional layered material.

[0126] In some variations, as shown in the figure, method 200 may further include pre-lithiation of a two-dimensional layered anode material (e.g., decalcified material) using a temperature-controlled process to form a lithiated layered material (e.g., Li). x Therefore, the need for possible in-situ pre-lithiation steps is eliminated or reduced, thereby saving associated costs and time.

[0127] Similar to removing the 230 cation from the precursor material, pre-lithiation can be performed using electrochemical methods. For example, as... Figure 3B As shown, the third current collector 362 (e.g., similar to...) Figure 1The negative current collector 32 shown can be aligned with the first current collector 332 and the two-dimensional layered anode material 312, and a second bias voltage (i.e., voltage) and / or current can be applied to allow lithium ions (Li...) to... + )352 moves from the third current collector 332 to the first current collector 332 to form a pre-lithiated layered anode material 314. For example, as shown in the figure, lithium ions (Li + )352 can move into the interlayer spaces or voids created by removing cations. In this way, the two-dimensional layered anode material 312 is ideal for re-intercalation and storage of lithium ions, because lithium ions can fill the voids created by removing cations.

[0128] The first current collector 332, the two-dimensional layered anode material 312, and the third current collector 362 are disposed in the second electrolyte solution. For example, in an exemplary intermittent method, an electronically conductive liquid-permeable cage comprising the first current collector 332 and the two-dimensional layered anode material 312 may be removed from the first electrolyte bath and placed in the second electrolyte bath before a second bias voltage and / or current is applied. When the desired state of charge is reached, the first current collector 332 and the pre-lithiated layered anode material 314 may be removed from the second electrolyte bath. In each case, the second electrolyte solution may include, by way of example only, 1M lithium hexafluorophosphate (LiPF6) in a solvent of ethylene carbonate (EC):propylene carbonate (PC) (1:1). When the two-dimensional layered anode material 312 contains silicon, the electrochemical exchange can be summarized as follows: (1) Anode: Li xLi+xe - (2) Cathode: 2D-Si+xLi+xe - 2D-Li x Si.

[0129] Re-reference Figure 2 In some variations, as shown, method 200 may include incorporating a two-dimensional layered anode material (and optionally, a first current collector) and / or a pre-lithiated layered anode material (and optionally, a first current collector) into a 250 cell for use as a negatively active material (and a negative current collector). Although not shown, in various aspects, method 200 may also include additional coating steps and / or other post-processing steps prior to incorporation into the cell, for example, to enhance the air stability of the two-dimensional layered anode material and / or the pre-lithiated layered anode material.

[0130] In various aspects, it is used for the negative electrode (e.g.) Figure 1 The layered anode material (e.g., a two-dimensional layered silicon allotrope) of the negative electrode 22 shown can be prepared using a continuous method (e.g., roll-to-roll method 400). For example, as Figure 4 As shown, the roll-to-roll method 400 may include a current collector 414 (e.g., similar to...). Figure 1 A precursor material 412 is coated on one or more surfaces of the negative current collector 32 (shown) to form a precursor electrode 410, and the precursor electrode 410 is moved through a first electrolyte bath 430 using a first roller 420.

[0131] Precursor material 412 comprises an ionic compound represented by MX2, where M is one of calcium (Ca) and magnesium (Mg), and X is one of silicon (Si), germanium (Ge), and / or boron (B). As the precursor electrode 410 moves through the first electrolyte bath 430, a first bias voltage (i.e., voltage) and / or current can be applied, as shown. The applied first bias voltage and / or current results in the removal of cations (e.g., Ca) from the precursor material 412. 2+ This allows the two-dimensional layered anode material 416 to remain on the current collector 414. As shown in the figure, cations (e.g., Ca) 2+ The precursor material 412 can be moved to the cation reservoir 450 (e.g., cathode or anode). The first electrolyte bath 430 may include a cation-compatible salt in a solvent solution, which dissolves (e.g., solvates) the cation and the cation-compatible salt. For example, when the precursor material contains calcium, the first electrolyte solution may contain 1M calcium tetrafluoroborate hydrate (Ca(BF4)2) in a solvent of ethylene carbonate (EC):propylene carbonate (PC) (1:1). The temperature of the first electrolyte bath 430 is controlled. In some variations, the temperature of the first electrolyte bath 430 may be controlled, for example, increased, to enhance diffusion.

[0132] In some variations, as shown in the figure, after forming the two-dimensional layered anode material 416, the roll-to-roll method 400 may further include moving the two-dimensional layered anode material 416 and the current collector 414 to a second electrolyte bath 432 using a second roller 422 and a third roller 424. As the two-dimensional layered anode material 416 and the current collector 414 move through the second electrolyte bath 432, the two-dimensional layered anode material 416 may be pre-lithiated. For example, similar to the method detailed above, a second bias voltage (i.e., voltage) and / or current may be used to induce lithium ions (Li₂). + Lithium ions (Li) migrate from the lithium source 452 to the two-dimensional layered anode material 416. + The cations can move into the interlayer spaces or voids created by removing cations to form a pre-lithiated anode material 480. The pre-lithiated anode material 480 (and optionally a current collector 414) can be incorporated into the battery to serve as a negatively active material (and a negative current collector). A second electrolyte bath 432 may include, by way of example only, 1M lithium hexafluorophosphate (LiPF6) in a solvent of ethylene carbonate (EC):propylene carbonate (PC) (1:1). In some variations, the temperature of the second electrolyte bath 432 can be controlled, for example, increased, to enhance diffusion.

[0133] Although not shown, in various aspects, the roll-to-roll method 400 may also include additional coating steps and / or other post-processing steps prior to incorporation into the battery, for example to enhance the air stability of the two-dimensional layered anode material and / or the pre-lithiated layered anode material.

[0134] In various aspects, a continuous flow method 500 can be used to prepare materials for the negative electrode (e.g., Figure 1 The layered anode material (e.g., a two-dimensional layered silicon allotrope) shown as the negative electrode 22. Figure 5 As shown, the continuous flow method 500 includes moving material from different compartments or containers (e.g., from a first compartment or container 530 to a second compartment or container 532), wherein each compartment or container includes a different source and bias voltage and / or current. The different compartments or containers (e.g., first and second containers 530, 532) include a circulating electrolyte solution 534 containing one or more lithium salts (e.g., calcium tetrafluoroborate hydrate (Ca(BF4)2) and / or lithium hexafluorophosphate (LiPF6)) in a solvent system, which includes, by way of example only, ethylene carbonate (EC) and / or propylene carbonate (PC). Although not shown, in some variations, the first container 530 and the second container 532 may include different electrolyte solutions. For example, the first container 530 may include 1M calcium tetrafluoroborate hydrate (Ca(BF4)2) in the solvent ethylene carbonate (EC):propylene carbonate (PC) (1:1), and the second container 532 may include 1M lithium hexafluorophosphate (LiPF6) in the solvent ethylene carbonate (EC):propylene carbonate (PC) (1:1).

[0135] As shown, the continuous flow method 500 may include introducing a precursor material 510 into a first container 530. The precursor material 510 may be an ionic powder material represented by MX2, where M is one of calcium (Ca) and magnesium (Mg), and X is one of silicon (Si), germanium (Ge), and / or boron (B). The first container 530 may include a counter electrode 542. A first bias voltage (i.e., voltage) and / or current may be applied such that as the precursor material 510 moves into and through the first container 530, cations 512 are removed from the precursor material 510 (e.g., electrochemical decalcification) to form a two-dimensional layered allotrope 514. The cations 512 move toward the counter electrode 542, while the two-dimensional layered allotrope 514 moves toward a second container 532 including a lithium source (e.g., lithium metal) 544. A second bias voltage (i.e., voltage) and / or current may be applied to the lithium source 544 such that the two-dimensional layered allotrope 514 is pre-lithiated (e.g., charged) to form the desired pre-lithiated anode material 516.

[0136] Although not shown, in various aspects, the continuous method 500 may also include separating the pre-lithiated anode material 516 using one or more known filtration or centrifugation methods. In some variations, the continuous method 500 may also include additional coating and / or other post-processing steps prior to incorporation into the battery, for example to enhance the air stability of the two-dimensional layered anode material and / or the pre-lithiated layered anode material.

[0137] 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. A method for forming a layered anode material, the method comprising: Cations are removed from a precursor material represented by MX2 using electrochemical extraction, where M is one of calcium (Ca) and magnesium (Mg), and X is one of silicon (Si), germanium (Ge), and boron (B). The precursor material is a layered ionic compound, and the removal of cations yields a two-dimensional structure defining a layered anode material. The removal of cations from the precursor material includes: Contact the precursor material with the electrolyte, and When the precursor material comes into contact with the electrolyte, a bias voltage and / or current are applied.

2. The method of claim 1, wherein the precursor material comprises alternating layers of M and X.

3. The method of claim 1, wherein the electrolyte is a first electrolyte, the bias voltage and / or current is a first bias voltage and / or current, the layered anode material is a pre-lithiated anode material, and the method further comprises pre-lithiating the two-dimensional structure, wherein pre-lithiating the two-dimensional structure comprises: To bring the two-dimensional structure into contact with the second electrolyte, and When the two-dimensional structure contacts the second electrolyte, a second bias voltage and / or current are applied to enable lithium ions (Li...) + They move into the interlayer spaces or voids created by the removal of cations.

4. The method of claim 3, wherein the first electrolyte is different from the second electrolyte, and the first bias voltage and / or current is different from the second bias voltage and / or current.

5. The method of claim 3, wherein the second electrolyte comprises a lithium source.

6. The method of claim 1, wherein the electrolyte comprises a cation-compatible salt.

7. The method of claim 1, wherein the precursor material is disposed in an electronically conductive liquid-permeable cage, and contacting the precursor material with the electrolyte comprises disposing the electronically conductive liquid-permeable cage in the electrolyte.

8. The method of claim 7, wherein the electrolyte is a first electrolyte, the bias voltage and / or current is a first bias voltage and / or current, and after applying the first bias voltage and / or current, the electronically conductive liquid-permeable cage comprises a two-dimensional structure, and the layered anode material is a pre-lithiated anode material, and The methods also include: Pre-lithiation of the two-dimensional structure, wherein pre-lithiation of the two-dimensional structure includes contacting a liquid-permeable cage containing the electronically conductive two-dimensional structure with a second electrolyte, and When a liquid-permeable cage comprising an electronically conductive two-dimensional structure contacts a second electrolyte, a second bias voltage and / or current are applied to induce lithium ions (Li... + They move into the interlayer spaces or voids created by the removal of cations.

9. The method of claim 1, wherein the precursor material is disposed on the current collector, and contacting the precursor material with the electrolyte comprises disposing the precursor material and the current collector in the electrolyte using one or more rollers.

10. The method of claim 9, wherein the electrolyte is a first electrolyte, the bias voltage and / or current is a first bias voltage and / or current, the one or more rollers are first rollers, the two-dimensional structure is disposed on the current collector after the first bias voltage and / or current is applied, and the layered anode material is a pre-lithiated anode material, and The methods also include: Pre-lithiation of the two-dimensional structure, wherein pre-lithiation of the two-dimensional structure includes using one or more second rollers to contact the two-dimensional structure and the current collector with a second electrolyte, and While the two-dimensional structure and the current collector are in contact with the second electrolyte, a second bias voltage and / or current are applied to induce movement of lithium ions (Li...). + It enters the interlayer space or voids created by the removal of cations.

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