Passive ion exchange for manufacturing layered anode materials

Abstract

Disclosed herein are passive ion exchange for manufacturing layered anode materials. The disclosure provides a method for forming a pre-lithiated layered anode material. The method includes contacting a precursor material with an electrolyte comprising one or more lithium salts and one or more solvents. The molarity of the electrolyte can be greater than or equal to about 0.1 M to less than or equal to the solubility limit of the one or more lithium salts in the one or more solvents. The precursor material can be a three-dimensional layered material, and the contacting of the precursor material with the electrolyte results in the removal of cations from the precursor material and the introduction of lithium ions from the electrolyte into interlayer spaces or voids created by the removal of the cations to form the pre-lithiated layered anode material.

Description

Technical Field

[0001] The present invention relates to a method for forming a pre-lithiated layered anode material, and a method for forming a pre-lithiated 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., passive ion exchange methods).

[0010] In various aspects, this disclosure provides a method for forming a pre-lithiated layered anode material. The method may include contacting a precursor material with an electrolyte comprising one or more lithium salts and one or more solvents. The molar concentration of the electrolyte may be greater than or equal to about 0.1 M and less than or equal to the solubility limit of the one or more lithium salts in the one or more solvents. The precursor material may be a three-dimensional layered material, and contacting the precursor material with the electrolyte may cause the removal of cations from the precursor material and the introduction of lithium ions from the electrolyte into the interlayer spaces or voids created by the removal of cations, thereby forming a pre-lithiated layered anode material.

[0011] In one aspect, the precursor material may 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), and the precursor material comprises alternating layers of M and X.

[0012] In one aspect, one or more lithium salts may be selected from: lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium chloride (LiCl), lithium carbonate (LiCO3), lithium hydroxide (LiOH), and combinations thereof.

[0013] In one aspect, one or more solvents may be selected from: ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), fluorinated ethylene carbonate (FEC), diethyl carbonate (DEC), methyl ethyl carbonate (EMC), and combinations thereof.

[0014] In one aspect, contacting the precursor material with the electrolyte may include immersing the precursor material in the electrolyte.

[0015] In one aspect, the method may further include stirring the electrolyte during contact between the precursor material and the electrolyte.

[0016] In one aspect, fluidized beds or electrolyte recirculation beds can be used to agitate the electrolyte.

[0017] In one respect, electrolytes can be stirred by simultaneously removing the used portion of the electrolyte and introducing a new portion of the electrolyte.

[0018] In one respect, the removal of used electrolytes and the introduction of new electrolytes occur continuously.

[0019] In one respect, the removal of used electrolytes and the introduction of new electrolytes occur periodically.

[0020] In one aspect, the method may further include placing a precursor material in an electronically conductive liquid-permeable cage, and contacting the precursor material with an electrolyte including placing the electronically conductive liquid-permeable cage in the electrolyte.

[0021] In one aspect, an electronically conductive liquid-permeable cage can be placed in a countercurrent reactor, and the electrolyte flows continuously through the countercurrent reactor.

[0022] In one respect, the new portion of electrolyte can be introduced into the first opening of the countercurrent reactor, and the used portion of electrolyte can be simultaneously removed from the second opening of the countercurrent reactor.

[0023] In one respect, the removal of used electrolytes and the introduction of new electrolytes occur continuously.

[0024] In one respect, the removal of used electrolytes and the introduction of new electrolytes occur periodically.

[0025] In one aspect, the method may further include heating the electrolyte during contact between the precursor material and the electrolyte. The electrolyte may be heated to a temperature greater than or equal to about 20°C to less than or equal to about 200°C.

[0026] In various aspects, this disclosure provides a method for forming a pre-lithiated layered anode material. The method may include contacting a precursor material with an electrolyte comprising one or more lithium salts and one or more solvents. The molar concentration of the electrolyte may be greater than or equal to about 0.1M and less than or equal to the solubility limit of the one or more lithium salts in the one or more solvents. The precursor material may 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). The method may further include stirring the electrolyte during the contact between the precursor material and the electrolyte, such that cations are removed from the precursor material, and lithium ions are introduced into the interlayer spaces or voids created by the removal of cations to form the pre-lithiated layered anode material.

[0027] In one aspect, the method may further include disposing of a precursor material in an electronically conductive, liquid-permeable cage, and contacting the precursor material with an electrolyte may include disposing of the electronically conductive, liquid-permeable cage in the electrolyte.

[0028] In one aspect, the method may further include heating the electrolyte during contact between the precursor material and the electrolyte. The electrolyte may be heated to a temperature greater than or equal to about 20°C to less than or equal to about 200°C.

[0029] In various aspects, this disclosure provides a method for forming a pre-lithiated layered anode material. The method may substantially consist of contacting a precursor material with an electrolyte comprising one or more lithium salts and one or more solvents. The molar concentration of the electrolyte may be greater than or equal to about 0.1M to less than or equal to the solubility limit of the one or more lithium salts in the one or more solvents. The precursor material may 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). Contact between the precursor material and the electrolyte causes cations to be removed from the precursor material and lithium ions to be introduced from the electrolyte into the interlayer spaces or voids created by the removal of cations, thereby forming a pre-lithiated layered anode material.

[0030] The present invention discloses the following embodiments:

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

[0032] A precursor material is contacted with an electrolyte comprising one or more lithium salts and one or more solvents, wherein the electrolyte has a molar concentration greater than or equal to about 0.1 M to less than or equal to the solubility limit of the one or more lithium salts in the one or more solvents, and wherein the precursor material is a three-dimensional layered material, and the contact between the precursor material and the electrolyte results in the removal of cations from the precursor material and the introduction of lithium ions from the electrolyte into the interlayer spaces or voids created by the removal of cations, to form the pre-lithiated layered anode material.

[0033] 2. According to the method of embodiment 1, 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), and the precursor material comprises alternating layers of M and X.

[0034] 3. According to the method of embodiment 1, the one or more lithium salts are selected from the following: lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium chloride (LiCl), lithium carbonate (LiCO3), lithium hydroxide (LiOH), and combinations thereof.

[0035] 4. According to the method of embodiment 3, the one or more solvents are selected from: ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), fluorinated ethylene carbonate (FEC), diethyl carbonate (DEC), methyl ethyl carbonate (EMC), and combinations thereof.

[0036] 5. The method according to embodiment 1, wherein contacting the precursor material with the electrolyte comprises immersing the precursor material in the electrolyte.

[0037] 6. The method according to embodiment 1, wherein the method further comprises:

[0038] The electrolyte is stirred during the contact between the precursor material and the electrolyte.

[0039] 7. The method according to embodiment 6, wherein the electrolyte is stirred using a fluidized bed or an electrolyte recirculation bed.

[0040] 8. The method according to embodiment 6, wherein the electrolyte is stirred by simultaneously removing the used portion of the electrolyte and introducing a new portion of the electrolyte.

[0041] 9. The method according to embodiment 8, wherein the removal of the used portion of electrolyte and the introduction of a new portion of electrolyte occur continuously.

[0042] 10. The method according to embodiment 8, wherein the removal of the used portion of electrolyte and the introduction of a new portion of electrolyte occur periodically.

[0043] 11. The method according to embodiment 6, wherein the method further comprises placing the precursor material in an electronically conductive liquid-permeable cage, and contacting the precursor material with the electrolyte comprises placing the electronically conductive liquid-permeable cage in the electrolyte.

[0044] 12. According to the method of embodiment 11, wherein the electronically conductive liquid-permeable cage is disposed in a countercurrent reactor, and the electrolyte flows continuously through the countercurrent reactor.

[0045] 13. According to the method of embodiment 12, a new portion of electrolyte is introduced into a first opening of the countercurrent reactor, while a used portion of electrolyte is removed from a second opening of the countercurrent reactor.

[0046] 14. The method according to embodiment 13, wherein the removal of the used portion of electrolyte and the introduction of a new portion of electrolyte occur continuously.

[0047] 15. The method according to embodiment 13, wherein the removal of the used portion of electrolyte and the introduction of a new portion of electrolyte occur periodically.

[0048] 16. The method according to embodiment 1, wherein the method further comprises:

[0049] The electrolyte is heated during contact between the precursor material and the electrolyte, wherein the electrolyte is heated to a temperature greater than or equal to about 20°C and less than or equal to about 200°C.

[0050] 17 A method for forming a pre-lithiated layered anode material, the method comprising:

[0051] The precursor material is contacted with an electrolyte comprising one or more lithium salts and one or more solvents, wherein the electrolyte has a molar concentration greater than or equal to about 0.1 M and less than or equal to the solubility limit of the one or more lithium salts in the one or more solvents, and wherein 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); and

[0052] The electrolyte is stirred during the contact between the precursor material and the electrolyte, so that cations are removed from the precursor material and lithium ions are introduced into the interlayer space or voids created by the removal of cations to form a pre-lithiated layered anode material.

[0053] 18. The method according to embodiment 17, wherein the method further comprises placing the precursor material in an electronically conductive liquid-permeable cage, and contacting the precursor material with the electrolyte comprises placing the electronically conductive liquid-permeable cage in the electrolyte.

[0054] 19. The method according to embodiment 17, wherein the method further comprises:

[0055] The electrolyte is heated during contact between the precursor material and the electrolyte, wherein the electrolyte is heated to a temperature greater than or equal to about 20°C and less than or equal to about 200°C.

[0056] 20. A method for forming a pre-lithiated layered anode material, the method comprising essentially the following:

[0057] A precursor material is contacted with an electrolyte comprising one or more lithium salts and one or more solvents, wherein the electrolyte has a molar concentration greater than or equal to about 0.1M and less than or equal to the solubility limit of the one or more lithium salts in the one or more solvents, and wherein 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), and the contact between the precursor material and the electrolyte results in the removal of cations from the precursor material and the introduction of lithium ions from the electrolyte into the interlayer spaces or voids created by the removal of the cations to form a pre-lithiated layered anode material.

[0058] 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

[0059] 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.

[0060] Figure 1 This is a schematic diagram of an exemplary electrochemical battery pack including layered electroactive materials according to various aspects of this disclosure;

[0061] Figure 2 This illustrates aspects of the present disclosure for use in manufacturing electrochemical battery packs (such as...). Figure 1 A flowchart illustrating an exemplary method for using layered electroactive materials in an exemplary electrochemical battery pack (as shown) and pre-lithiating the layered electroactive materials; and

[0062] Figure 3 The use of a countercurrent reactor for forming cells in an electrochemical cell array (such as...) is shown according to various aspects of this disclosure. Figure 1 An exemplary method for using layered electroactive materials in an exemplary electrochemical battery pack shown in the figure;

[0063] In the various views of the accompanying drawings, the corresponding reference numerals denote the respective components. Detailed Implementation

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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%.

[0071] 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.

[0072] Exemplary embodiments will now be described more fully with reference to the accompanying drawings.

[0073] 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 a passive ion 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.

[0074] 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.

[0075] 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.

[0076] 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).

[0077] 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).

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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).

[0090] 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).

[0091] 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.

[0092] 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.

[0093] 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).

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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).

[0099] 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.

[0100] 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.%.

[0101] In various aspects, this disclosure provides preparation for anodes (e.g. Figure 1The method for preparing a pre-lithiated layered anode material (e.g., a two-dimensional layered silicon allotrope) for the negative electrode 22 shown in the illustration. For example, this disclosure contemplates a method for preparing a pre-lithiated layered anode material using a passive ion exchange method. The method typically includes contacting a precursor material with a highly concentrated lithium electrolyte. In each case, the method can be performed using either a batch or continuous process.

[0102] Figure 2 An exemplary method 200 for forming a pre-lithiated layered anode material is illustrated. Method 200 includes contacting a precursor material with a highly concentrated lithium electrolyte 220. The highly concentrated lithium electrolyte may contain one or more lithium salts in a solvent system. By way of example only, one or more lithium salts may include lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium chloride (LiCl), lithium carbonate (LiCO3), lithium hydroxide (LiOH), and combinations thereof. One or more solvents may include, by way of example only, ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), fluorinated ethylene carbonate (FEC), diethyl carbonate (DEC), methyl ethyl carbonate (EMC), and combinations thereof. The molar concentration of the highly concentrated lithium electrolyte may be greater than or equal to about 0.1 M to less than or equal to the solubility limit of one or more lithium salts in the solvent system. In some variations, contacting the precursor material with a highly concentrated lithium electrolyte 220 may include placing or immersing the precursor material in the highly concentrated lithium electrolyte.

[0103] In each case, the precursor material can 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) 2+ Lithium ions readily undergo ion exchange. For example, contacting a precursor material with a highly concentrated lithium electrolyte at 220° promotes the removal of cations from the precursor material, resulting in a two-dimensional layered material (e.g., van der Waals crystals). This process is commonly referred to as ion exchange interdiffusion. When cations are removed, lithium ions (Li...) readily exchange with the electrolyte. + The lithium ions can migrate from the highly concentrated lithium electrolyte into the interlayer spaces or voids created by the removal of cations to form a pre-lithiated layered anode material. The cations can be removed from the precursor material, and the lithium ions (Li...) +The cations can move into the interlayer spaces or voids, which are generated by removing cations via natural ion diffusion assisted by forced convection, which is a result of the ion concentration gradient at the interface between the precursor material particles and the highly concentrated lithium electrolyte. Therefore, method 200 provides a one-step simultaneous method for removing cations and pre-lithiating the two-dimensional layered material, eliminating or reducing the cost and time associated with subsequent lithiation steps. In some variations, substantially all, 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 can be removed from the precursor material and converted to lithium ions (Li). + ) replacement.

[0104] In various aspects, as shown in the figure, method 200 may include obtaining or preparing the 210 precursor material. For example, preparing the 210 precursor material 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.

[0105] In other variations, method 200 may include stirring 230 of the highly concentrated lithium electrolyte (e.g., when a precursor material is added to the highly concentrated lithium electrolyte and / or when the precursor material moves through the highly concentrated lithium electrolyte) to ensure homogeneity, such as ensuring that ion exchange occurs to substantially all particles to the same or similar degree. In some variations, stirring 230 of the highly concentrated lithium electrolyte may be performed by continuously introducing or replacing fresh highly concentrated lithium electrolyte as the cation concentration increases and the lithium ion concentration decreases (e.g., ...). Figure 3 (as shown) in order to update the gradient (i.e., maintain the concentration difference) and restore the driving force, and / or use a fluidized bed or electrolyte recirculation bed to break the boundary layer at the solid-liquid interface.

[0106] In various aspects, as shown in the figures, method 200 may include heating 240 (i.e., raising the temperature) a highly concentrated lithium electrolyte to enhance diffusion. For example, the temperature of the highly concentrated lithium electrolyte may be raised when a precursor material is added to the highly concentrated lithium electrolyte and / or after a predetermined time period, such as during stirring 230 of the precursor material. In each case, the highly concentrated lithium electrolyte may be heated to a temperature greater than or equal to about 20°C to less than or equal to about 250°C.

[0107] Re-reference Figure 2In 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 to serve 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, such as to enhance the air stability of the pre-lithiated layered anode material, and / or to mix the pre-lithiated layered anode material with other negatively active materials, such as three-dimensional silicon allotropes and / or graphite / graphene.

[0108] In various aspects, it is used for the negative electrode (e.g.) Figure 1 The layered anode material (e.g., a pre-lithiated two-dimensional layered silicon allotrope) of the negative electrode 22 shown can be prepared using a continuous method. For example, as Figure 3 As shown, a countercurrent reactor 300 can be used, in which a highly concentrated lithium electrolyte 330 is continuously introduced and removed (e.g., Figure 3 (As indicated by the arrow in the diagram) and moves through an electronically conductive, liquid-permeable cage 320 containing a precursor material (not shown). As described above, the molar concentration of the highly concentrated lithium electrolyte 330 can be greater than or equal to about 0.1M to less than or equal to the solubility limit of one or more lithium salts in a solvent system. The precursor material can 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).

[0109] As shown in the figure, when introduced (e.g., at the first opening 302), the highly concentrated lithium electrolyte 330 has a high concentration of lithium ions 340. As the highly concentrated lithium electrolyte 330 moves through the electronically conductive liquid-permeable cage 320, the lithium ions 340 exchange with cations 350, forming a pre-lithiated layered anode material as detailed above. This pre-lithiated layered anode material remains in the electronically conductive liquid-permeable cage 320 as the highly concentrated lithium electrolyte 330 moves toward the second opening or outlet 304. After a period of time, the pre-lithiated layered anode material can be extracted from the electronically conductive liquid-permeable cage 320.

[0110] 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 pre-lithiated layered anode material, the method comprising: A precursor material is contacted with an electrolyte comprising one or more lithium salts and one or more solvents, wherein the electrolyte has a molar concentration greater than or equal to 0.1 M and less than or equal to the solubility limit of the one or more lithium salts in the one or more solvents, and wherein the precursor material is a three-dimensional layered material, and the contact between the precursor material and the electrolyte results in the removal of cations from the precursor material, and lithium ions are introduced from the electrolyte into the interlayer spaces or voids created by the removal of cations without disrupting the crystal structure of the precursor material, to form the pre-lithiated layered anode material. 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), and the precursor material comprises alternating layers of M and X.

2. The method according to claim 1, wherein the one or more lithium salts are selected from the following: lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium chloride (LiCl), lithium carbonate (LiCO3), lithium hydroxide (LiOH), and combinations thereof.

3. The method according to claim 2, wherein the one or more solvents are selected from: ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), fluorinated ethylene carbonate (FEC), diethyl carbonate (DEC), methyl ethyl carbonate (EMC), and combinations thereof.

4. The method of claim 1, wherein contacting the precursor material with the electrolyte comprises immersing the precursor material in the electrolyte.

5. The method according to claim 1, wherein the method further comprises: The electrolyte is stirred during the contact between the precursor material and the electrolyte.

6. The method of claim 5, wherein the electrolyte is stirred using a fluidized bed or an electrolyte recirculation bed.

7. The method of claim 5, wherein the electrolyte is stirred by simultaneously removing the used portion of the electrolyte and introducing a new portion of the electrolyte.

8. The method of claim 7, wherein the removal of the used portion of electrolyte and the introduction of a new portion of electrolyte occur continuously.

9. The method of claim 7, wherein the removal of the used portion of electrolyte and the introduction of a new portion of electrolyte occur periodically.

10. The method of claim 5, wherein the method further comprises placing the precursor material in an electronically conductive liquid-permeable cage, and contacting the precursor material with the electrolyte comprises placing the electronically conductive liquid-permeable cage in the electrolyte.

11. The method of claim 10, wherein the electronically conductive liquid-permeable cage is disposed in a countercurrent reactor, and the electrolyte flows continuously through the countercurrent reactor.

12. The method of claim 11, wherein a new portion of electrolyte is introduced into a first opening of the countercurrent reactor, while a used portion of electrolyte is removed from a second opening of the countercurrent reactor.

13. The method of claim 12, wherein the removal of the used portion of electrolyte and the introduction of a new portion of electrolyte occur continuously.

14. The method of claim 12, wherein the removal of the used portion of electrolyte and the introduction of a new portion of electrolyte occur periodically.

15. The method of claim 1, wherein the method further comprises: The electrolyte is heated during contact between the precursor material and the electrolyte, wherein the electrolyte is heated to a temperature greater than or equal to 20°C and less than or equal to 200°C.

16. A method for forming a pre-lithiated layered anode material, the method comprising: The precursor material is contacted with an electrolyte comprising one or more lithium salts and one or more solvents, wherein the electrolyte has a molar concentration greater than or equal to 0.1M and less than or equal to the solubility limit of one or more lithium salts in one or more solvents, and wherein 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). as well as The electrolyte is stirred during the contact between the precursor material and the electrolyte, so that cations are removed from the precursor material and lithium ions are introduced into the interlayer spaces or voids created by the removal of cations without disrupting the lattice structure of the precursor material, to form a pre-lithiated layered anode material.

17. The method of claim 16, wherein the method further comprises placing the precursor material in an electronically conductive liquid-permeable cage, and contacting the precursor material with the electrolyte comprises placing the electronically conductive liquid-permeable cage in the electrolyte.

18. The method of claim 16, wherein the method further comprises: The electrolyte is heated during contact between the precursor material and the electrolyte, wherein the electrolyte is heated to a temperature greater than or equal to 20°C and less than or equal to 200°C.

19. A method for forming a pre-lithiated layered anode material, the method comprising: A precursor material is contacted with an electrolyte comprising one or more lithium salts and one or more solvents, wherein the electrolyte has a molar concentration greater than or equal to 0.1M and less than or equal to the solubility limit of the one or more lithium salts in the one or more solvents, and wherein 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), and the contact between the precursor material and the electrolyte results in the removal of cations from the precursor material and the introduction of lithium ions from the electrolyte into the interlayer spaces or voids created by the removal of the cations without disrupting the lattice structure of the precursor material to form a pre-lithiated layered anode material.

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