Pre-lithiated silicon particles and methods of forming the same

Abstract

This disclosure provides a method for manufacturing a negative electrode material for a cyclic lithium-ion electrochemical battery. The method includes centrifugally distributing a precursor comprising silicon, lithium, and an additional metal (M) selected from aluminum (Al), chromium (Cr), titanium (Ti), niobium (Nb), molybdenum (Mo), zirconium (Zr), yttrium (Y), cerium (Ce), and combinations thereof by contacting the precursor with a rotating surface in a centrifugal atomizing reactor; and solidifying the precursor to form a plurality of substantially spherical solid electroactive particles comprising Li. 4.4x Si x M y , where x is greater than 0 to less than or equal to about 0.85 and y corresponds to a weight percentage of M greater than or equal to 0.1 wt% to less than or equal to about 10 wt%.

Description

Technical Field

[0001] This invention relates to pre-lithiated silicon particles and methods for forming the same. 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 act as the positive electrode or cathode, and the other electrode can act as the negative electrode or anode. The separator and / or electrolyte can be arranged between the negative and positive electrodes. The electrolyte is adapted to conduct lithium ions between the electrodes and, similar to the two electrodes, the electrolyte 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, the solid electrolyte can physically separate the electrodes so that separate separators are not required.

[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 electrode to the negative electrode during charging and in the reverse direction during discharging. Such lithium-ion battery packs can reversibly supply power to a relevant load device as needed. More specifically, the lithium-ion battery pack can supply power to the load device until the lithium content at the negative electrode is effectively depleted. The battery pack can then be recharged by reversing the flow of a suitable direct current between the electrodes.

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

[0006] However, in various cases, due to conversion reactions during the first cycle and / or the formation of a solid electrolyte interphase (SEI) layer on the negative electrode, and due to ongoing lithium loss such as from the continuous breakdown of the SEI, some of the intercalated lithium remains with the negative electrode after the first cycle. This permanent loss of lithium ions can lead to a reduction in specific energy and power in the battery pack, for example, due to an increase in the mass of the positive electrode that does not participate in the reversible operation of the battery pack. For example, lithium-ion battery packs may experience an irreversible capacity loss of greater than or equal to about 5% to less than or equal to about 30% after the first cycle, and in the case of silicon-containing negative electrodes, an irreversible capacity loss of greater than or equal to about 20% to less than or equal to about 40% after the first cycle. Therefore, it is desirable to develop improved electrode and electroactive materials, as well as methods for their manufacture and use, to address these challenges. Summary of the Invention

[0007] This section provides a general overview of this disclosure and is not a full disclosure of its complete scope or all its features.

[0008] This disclosure relates to pre-lithiation electroactive materials for use in cyclic lithium-ion electrochemical batteries and methods for forming pre-lithiation electroactive materials. The pre-lithiation electroactive material may include spherical lithium-silicon particles and a passivation surface film or passivation layer coated thereon. The method may include centrifugally distributing a molten precursor in a centrifugal atomizing reactor, wherein the molten precursor comprises lithium... 4.4x Si x M y The defined silicon alloy powder, wherein x is greater than 0 to less than or equal to about 0.85, M is at least one of aluminum (Al), chromium (Cr), titanium (Ti), niobium (Nb), molybdenum (Mo), zirconium (Zr), yttrium (Y) and cerium (Ce), and y corresponds to a weight percentage of M greater than or equal to 0.1 wt% to less than or equal to about 10 wt%.

[0009] In various aspects, this disclosure provides a method for manufacturing a negative electrode material for a cyclic lithium-ion electrochemical battery. The method includes contacting a precursor comprising silicon, lithium, and a metal (M) selected from aluminum (Al), chromium (Cr), titanium (Ti), niobium (Nb), molybdenum (Mo), zirconium (Zr), yttrium (Y), cerium (Ce), and combinations thereof with a rotating surface in a centrifugal atomizing reactor and solidifying the precursor to form a plurality of substantially spherical solid electroactive particles. The solid electroactive particles comprise Li 4.4x Si x M y , where x is greater than 0 to less than or equal to about 0.85 and y corresponds to a weight percentage of M greater than or equal to 0.1 wt% to less than or equal to about 10 wt%.

[0010] In one aspect, the rotating surface may include one or more metallic coatings. Each metallic coating may contain one or more of gold (Au), aluminum (Al), and silver (Ag). Each metallic coating may have a thickness greater than or equal to about 0.01 µm and less than or equal to about 0.1 µm.

[0011] In one aspect, the method may further include, for each of the plurality of substantially circular solid electroactive particles, passivating metal (M) to form a passivation coating on the exposed surface of each substantially circular solid electroactive particle.

[0012] In one aspect, the passivating metal (M) may include exposing the plurality of substantially circular solid electroactive particles to oxygen or nitrogen.

[0013] In one respect, during the centrifugal distribution process, the temperature in the centrifugal atomizing reactor can be greater than or equal to 400°C to less than or equal to 1,000°C.

[0014] In one respect, the environment in a centrifugal atomizing reactor may contain less than or equal to about 0.5% by weight of any oxygen-containing substance.

[0015] In one respect, the flow rate of the centrifugal atomizing reactor can be greater than or equal to 50 kg / h to less than or equal to about 500 kg / h.

[0016] In one aspect, the average D50 diameter of the plurality of substantially spherical solid electroactive particles may be greater than or equal to about 1 μm to less than or equal to about 20 μm.

[0017] In one respect, the plurality of substantially spherical solid electroactive particles may have a polydispersity index of less than or equal to about 1.2.

[0018] In one aspect, the method may further include preparing a precursor. Preparing the precursor may include forming a mixture by contacting a first material containing lithium and having a first temperature and a second material containing silicon and having a second temperature in a mixing chamber to form a first mixture. The first and second materials may each enter the mixing chamber at a pressure greater than or equal to about 10 PSI. The second temperature may be higher than the first temperature.

[0019] In one respect, the first temperature may be equal to or higher than the melting point temperature of lithium, and the second temperature may be equal to or higher than the melting point temperature of silicon.

[0020] In one aspect, the contact can occur by introducing lithium from a lithium source into the mixing chamber using a first supply line and introducing silicon from a silicon source into the mixing chamber using a second supply line.

[0021] In one aspect, the first supply line may include a first metering pump and the second supply line may include a second metering pump. The first metering pump can control the pressure and rate at which lithium enters the mixing chamber. The second metering pump can control the pressure and rate at which silicon enters the mixing chamber.

[0022] In one aspect, the method may further include removing the mixture from the mixing chamber, adding an additional metal (M) to the mixture, and heating the mixture and the metal (M) to form a precursor.

[0023] In various aspects, this disclosure provides a method for manufacturing a negative electrode material for a cyclic lithium-ion electrochemical battery. The method may include contacting a first material containing lithium and having a first temperature and a second material containing silicon and having a second temperature in a mixing chamber to form a precursor. The first and second materials may each enter the mixing chamber at a pressure greater than or equal to about 10 PSI. The first temperature may be equal to or higher than the melting point temperature of lithium. The second temperature may be equal to or higher than the melting point temperature of silicon. The method may further include adding a metal (M) selected from aluminum (Al), chromium (Cr), titanium (Ti), niobium (Nb), molybdenum (Mo), zirconium (Zr), yttrium (Y), cerium (Ce), and combinations thereof to the precursor and heating the precursor and the metal (M) to form a molten precursor; and centrifugally distributing the molten precursor by contacting it with a rotating surface in a centrifugal atomizing reactor and solidifying the molten precursor to form a plurality of substantially spherical solid electroactive particles. The plurality of substantially spherical solid electroactive particles may contain Li 4.4x Si x M y , where x is greater than 0 and less than or equal to about 0.85 and y corresponds to a weight percentage of M greater than or equal to 0.1 wt% and less than or equal to about 10 wt%. The plurality of substantially spherical solid electroactive particles may have an average D50 diameter less than or equal to about 20 micrometers.

[0024] In one aspect, the rotating surface may include one or more metallic coatings. Each metallic coating may contain one or more of gold (Au), aluminum (Al), and silver (Ag). Each metallic coating may have a thickness greater than or equal to about 0.01 µm and less than or equal to about 0.1 µm.

[0025] In one aspect, the method may further include, for each of the plurality of substantially circular solid electroactive particles, passivating metal (M) to form a passivation coating on the exposed surface of each substantially circular solid electroactive particle.

[0026] In one aspect, the passivating metal (M) may include exposing the plurality of substantially circular solid electroactive particles to oxygen or nitrogen.

[0027] In one aspect, the contact can occur by introducing lithium from a lithium source into the mixing chamber using a first supply line and introducing silicon from a silicon source into the mixing chamber using a second supply line.

[0028] In one aspect, the method may further include removing the precursor from the mixing chamber.

[0029] In various aspects, this disclosure provides negatively charged active particles for use in electrochemical cells for cycling lithium-ions. The negatively charged active particles may include a core region and a passivation coating on an exposed surface of the core region. The core region may contain Li 4.4x Si x M y , where x is greater than 0 to less than or equal to about 0.85, M is a metal (M) selected from aluminum (Al), chromium (Cr), titanium (Ti), niobium (Nb), molybdenum (Mo), zirconium (Zr), yttrium (Y), cerium (Ce) and combinations thereof, and y corresponds to a weight percentage of M greater than or equal to 0.1 wt% to less than or equal to about 10 wt%.

[0030] In one aspect, the passivation coating can be formed by oxidizing a metal (M).

[0031] In one aspect, the passivation coating may be a nitride layer formed by exposing the metal (M) to a nitrogen-containing environment.

[0032] The present invention discloses the following embodiments.

[0033] 1. A method for manufacturing a negative electrode material for a cyclic lithium-ion electrochemical battery, the method comprising:

[0034] A precursor comprising silicon, lithium, and a metal (M) selected from aluminum (Al), chromium (Cr), titanium (Ti), niobium (Nb), molybdenum (Mo), zirconium (Zr), yttrium (Y), cerium (Ce), and combinations thereof is contacted with a rotating surface in a centrifugal atomizing reactor and the precursor is solidified to form a plurality of substantially spherical solid electroactive particles, comprising Li 4.4x Si x M y , where x is greater than 0 to less than or equal to about 0.85 and y corresponds to a weight percentage of M greater than or equal to 0.1 wt% to less than or equal to about 10 wt%.

[0035] 2. The method according to embodiment 1, wherein the rotating surface comprises one or more metal coatings, wherein each metal coating comprises one or more of gold (Au), aluminum (Al) and silver (Ag) and has a thickness greater than or equal to about 0.01 µm to less than or equal to about 0.1 µm.

[0036] 3. The method according to embodiment 1 further includes, for each of the plurality of substantially circular solid electroactive particles, a passivating metal (M) to form a passivation coating on the exposed surface of each substantially circular solid electroactive particle.

[0037] 4. The method according to embodiment 3, wherein the method further comprises:

[0038] Passivating metals (M) include those that expose the many substantially spherical solid electroactive particles to oxygen or nitrogen.

[0039] 5. The method according to embodiment 1, wherein during the contact process, the temperature in the centrifugal atomizing reactor is greater than or equal to 400°C and less than or equal to 1,000°C.

[0040] 6. The method according to embodiment 1, wherein the environment in the centrifugal atomizing reactor has less than or equal to about 0.5% by weight of any oxygen-containing substance.

[0041] 7. The method according to embodiment 1, wherein the flow rate of the centrifugal atomizing reactor is greater than or equal to 50 kg / h to less than or equal to about 500 kg / h.

[0042] 8. According to the method of embodiment 1, wherein the average D50 diameter of the plurality of substantially spherical solid electroactive particles is greater than or equal to about 1 μm to less than or equal to about 20 μm, and the plurality of substantially spherical solid electroactive particles have a polydispersity index of less than or equal to about 1.2.

[0043] 9. The method according to embodiment 1, wherein the method further comprises:

[0044] Preparation of precursors, wherein the preparation of precursors includes:

[0045] The mixture is formed as follows: a lithium-containing first material having a first temperature and a silicon-containing second material having a second temperature are brought into contact in a mixing chamber to form a first mixture, wherein the first material and the second material each enter the mixing chamber at a pressure greater than or equal to about 10 PSI, and the second temperature is higher than the first temperature.

[0046] 10. The method according to embodiment 9, wherein the first temperature is equal to or higher than the melting point temperature of lithium, and the second temperature is equal to or higher than the melting point temperature of silicon.

[0047] 11. The method according to embodiment 9, wherein the contact occurs by introducing lithium from a lithium source into the mixing chamber using a first supply line and introducing silicon from a silicon source into the mixing chamber using a second supply line, and

[0048] The first supply line includes a first metering pump and the second supply line includes a second metering pump. The first metering pump controls the pressure and rate at which lithium enters the mixing chamber, and the second metering pump controls the pressure and rate at which silicon enters the mixing chamber.

[0049] 12. The method according to embodiment 11, wherein the method further comprises:

[0050] The mixture is removed from the mixing chamber, metal (M) is added to the mixture, and the mixture and metal (M) are heated to form a precursor.

[0051] 13. A method for manufacturing a negative electrode material for a cyclic lithium-ion electrochemical battery, the method comprising:

[0052] A first material containing lithium and having a first temperature and a second material containing silicon and having a second temperature are brought into contact in a mixing chamber to form a precursor, wherein the first material and the second material are each introduced into the mixing chamber at a pressure greater than or equal to about 10 PSI, and the first temperature is equal to or higher than the melting point temperature of lithium and the second temperature is equal to or higher than the melting point temperature of silicon.

[0053] A metal (M) selected from aluminum (Al), chromium (Cr), titanium (Ti), niobium (Nb), molybdenum (Mo), zirconium (Zr), yttrium (Y), cerium (Ce), and combinations thereof is added to the precursor and the precursor and metal (M) are heated to form a molten precursor; and

[0054] The molten precursor is centrifugally distributed and solidified by contacting it with a rotating surface in a centrifugal atomizing reactor to form numerous substantially spherical solid electroactive particles containing Li. 4.4x Si x M y , where x is greater than 0 to less than or equal to about 0.85 and y corresponds to a weight percentage of M greater than or equal to 0.1 wt% to less than or equal to about 10 wt%, and has an average D50 diameter less than or equal to about 20 micrometers.

[0055] 14. The method according to embodiment 13, wherein the rotating surface comprises one or more metal coatings, wherein each metal coating comprises one or more of gold (Au), aluminum (Al) and silver (Ag), and each metal coating has a thickness greater than or equal to about 0.01 µm and less than or equal to about 0.1 µm.

[0056] 15. The method according to embodiment 13, wherein the method further comprises, for each of the plurality of substantially circular solid electroactive particles, passivating metal (M) to form a passivation coating on the exposed surface of each substantially circular solid electroactive particle.

[0057] 16. The method according to embodiment 13, wherein the passivating metal (M) comprises exposing the plurality of substantially circular solid electroactive particles to oxygen or nitrogen.

[0058] 17. The method according to embodiment 13, wherein the contact occurs by introducing lithium from a lithium source into the mixing chamber using a first supply line and introducing silicon from a silicon source into the mixing chamber using a second supply line, and the method further includes removing the precursor from the mixing chamber.

[0059] 18. Negatively charged active particles for use in electrochemical batteries for cycling lithium ions, said negatively charged active particles comprising:

[0060] Contains Li 4.4x Si x M y The core region, where x is greater than 0 and less than or equal to about 0.85, M is a metal (M) selected from aluminum (Al), chromium (Cr), titanium (Ti), niobium (Nb), molybdenum (Mo), zirconium (Zr), yttrium (Y), cerium (Ce) and combinations thereof, and y corresponds to a weight percentage of M greater than or equal to 0.1 wt% and less than or equal to about 10 wt%, and

[0061] Passivation coating on the exposed surface of the core region.

[0062] 19. The negatively charged active particles according to embodiment 18, wherein the passivation coating is formed by oxidizing a metal (M).

[0063] 20. The negatively charged active particles according to embodiment 18, wherein the passivation coating is a nitride layer formed by exposing the metal (M) to a nitrogen-containing environment.

[0064] Other applicable fields will be apparent from the description provided herein. The description and specific examples in this invention are intended to be illustrative only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0065] The accompanying drawings described herein are for illustrative purposes only and not for all possible embodiments, and are not intended to limit the scope of this disclosure.

[0066] Figure 1 This is a schematic diagram of an exemplary electrochemical battery pack;

[0067] Figure 2 This is a cross-sectional view of an exemplary pre-lithiated electroactive material according to various aspects of this disclosure;

[0068] Figure 3 Exemplary collision mixing methods are shown according to various aspects of this disclosure; and

[0069] Figure 4 Showing various aspects of this disclosure for forming such Figure 2 The cells shown and used in electrochemical battery packs (such as...) Figure 1 An exemplary centrifugal atomizing reactor for pre-lithiated electroactive materials (as shown in the diagram).

[0070] Several views are shown throughout the accompanying drawings, with corresponding reference numerals indicating the respective parts. Detailed Implementation

[0071] Exemplary embodiments are provided to make this disclosure thorough and to fully convey the scope to those skilled in the art. Numerous specific details, such as examples of specific compositions, components, apparatuses, and methods, are set forth to provide a thorough 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 embodied in many different forms, and none of these should be construed as limiting the scope of this disclosure. In some exemplary embodiments, well-known processes, well-known apparatus structures, and well-known technologies are not described in detail.

[0072] The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be restrictive. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” used herein are intended to also include the plural forms. The terms “comprising,” “including,” and “having” are inclusive and therefore 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 sets thereof. While the open-ended term “comprising” is to be understood as a non-restrictive term used to describe and claim the various embodiments set forth herein, in some respects it may be understood alternatively as a more restrictive and binding term, such as “consisting of” or “substantially consisting of.” Therefore, for any given embodiment that describes a composition, material, component, element, feature, integer, operation, and / or process step, this disclosure also specifically includes embodiments consisting of or substantially consisting of such described compositions, materials, components, elements, features, integers, operations, and / or process steps. In the case of “consisting of…”, the alternative embodiments exclude any additional compositions, materials, components, elements, features, integers, operations and / or process steps, while in the case of “essentially composed of…”, any additional compositions, materials, components, elements, features, integers, operations and / or process steps that substantially affect the essential and novel characteristics are excluded from such embodiments, but such embodiments may include any compositions, materials, components, elements, features, integers, operations and / or process steps that do not substantially affect the essential and novel characteristics.

[0073] Unless explicitly specified as the order of implementation, no method steps, processes, and operations described herein should be construed as requiring them to be performed in the particular order discussed or illustrated. It should also be understood that, unless otherwise indicated, additional or alternative steps may be employed.

[0074] When a component, element, or layer is mentioned as being “on,” “engaged to,” “connected to,” or “coupled to” another component or layer, it may be directly on, directly engaged to, connected to, or coupled to that other component, element, or layer, or there may be intermediate elements or layers present. In contrast, when an element is mentioned as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another component or layer, there may be no intermediate elements or layers present. Other terms used to describe relationships between elements should be interpreted in a similar manner (e.g., “between” vs. “directly between,” “adjacent” vs. “directly adjacent,” etc.). The term “and / or” as used herein includes any and all combinations of one or more of the relevant enumerations.

[0075] 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 specified. 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 this exemplary embodiment.

[0076] 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 between one element or feature as shown in the figure and one or more other elements or features. In addition to the orientations depicted in the figure, spatially or temporally relative terms may be intended to cover different orientations of the device or system during use or operation.

[0077] Throughout this disclosure, numerical values ​​represent approximate measurements or range limits to cover small deviations from a given value and embodiments having approximately the stated value as well as embodiments having the exact stated value. Except in the working embodiments provided at the end of the detailed embodiments, all numerical values ​​of parameters (e.g., quantities or conditions) in this specification (including the appended claims) are to be understood as being modified in all cases by the term “about,” regardless of whether “about” actually appears before the numerical value. “About” indicates that the numerical value allows for a slight degree of imprecision (a degree close to the accuracy of the value; approximately or reasonably close to the value; nearly). If the imprecision provided by “about” is not otherwise understood in the art in this common sense, then “about” as used herein at least indicates a variation that may be caused by common methods of measuring and using such parameters. For example, “about” may include variations 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%.

[0078] Furthermore, the disclosure of the range includes the disclosure of all values ​​throughout the range and the disclosure of further subdivisions of the range, including the endpoints and subranges given for the range.

[0079] Exemplary embodiments will now be described more fully with reference to the accompanying drawings.

[0080] This disclosure relates to pre-lithiation electroactive materials for use in cyclic lithium-ion electrochemical batteries and methods for forming pre-lithiation electroactive materials. The pre-lithiation electroactive material may include spherical lithium-silicon particles and a passivation surface film or passivation layer coated thereon. The method may include centrifugally distributing a molten precursor in a centrifugal atomizing reactor, wherein the molten precursor comprises lithium... 4.4x Si x M y The defined silicon alloy powder, wherein x is greater than 0 to less than or equal to about 0.85, M is at least one of aluminum (Al), chromium (Cr), titanium (Ti), niobium (Nb), molybdenum (Mo), zirconium (Zr), yttrium (Y) and cerium (Ce), and y corresponds to a weight percentage of M greater than or equal to 0.1 wt% to less than or equal to about 10 wt%.

[0081] A typical lithium-ion battery pack includes a first electrode (such as a positive electrode or cathode), a second electrode (such as a negative electrode or anode), and a separator and / or electrolyte disposed between them. Typically, in a lithium-ion battery pack, the battery pack or cells can be stacked or wound to configure electrical connections 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 reverse direction during discharging. The electrolyte is adapted to conduct lithium ions (or sodium ions in the case of a sodium-ion battery pack, and so on) and can be in liquid, gel, or solid form. For example, exemplary and schematic illustrations of an electrochemical cell (also called a battery pack) 20 are shown... Figure 1 middle.

[0082] Such batteries are used in vehicle or automotive transportation applications (e.g., motorcycles, boats, tractors, buses, motorhomes, campervans, and tanks). However, this technology can be used in a wide variety of other industries and applications, including, as non-limiting examples, aerospace components, consumer products, devices, buildings (e.g., residences, offices, sheds, and warehouses), office equipment and furniture, industrial equipment machinery, agricultural or farm equipment, or heavy machinery. Furthermore, although the illustrated examples include a single cathode and a single anode, those skilled in the art will recognize that this teaching is applicable to a variety of other configurations, including those having one or more cathodes and one or more anodes, and various current collectors (which have an electroactive layer disposed on or near one or more of their surfaces).

[0083] Battery pack 20 includes a negative electrode 22 (e.g., anode), a positive electrode 24 (e.g., cathode), and a separator 26 disposed between the two electrodes 22, 24. Separator 26 provides electrical isolation between electrodes 22, 24—preventing physical contact. Separator 26 also provides a path of minimal resistance for the internal passage of lithium ions and, in some cases, associated anions, during lithium-ion cycling. In various aspects, separator 26 comprises an electrolyte 30, which may also be present in the negative electrode 22 and the positive electrode 24 in some aspects. In some variations, separator 26 may be formed of a solid electrolyte. For example, separator 26 may be defined by a plurality of solid electrolyte particles (not shown).

[0084] The negative electrode current collector 32 may be disposed at or near the negative electrode 22. The negative electrode current collector 32 may be a metal foil, metal mesh or sieve, or expanded metal containing copper or any other suitable conductive material known to those skilled in the art. The positive electrode current collector 34 may be disposed at or near the positive electrode 24. The positive electrode current collector 34 may be a metal foil, metal mesh or sieve, or expanded metal containing aluminum or any other suitable conductive material known to those skilled in the art. The negative electrode current collector 32 and the positive electrode current collector 34 respectively collect free electrons from and move free electrons to the external circuit 40. For example, the interruptible external circuit 40 and the load device 42 may connect the negative electrode 22 (through the negative electrode current collector 32) and the positive electrode 24 (through the positive electrode current collector 34).

[0085] Battery pack 20 generates current during discharge through a reversible electrochemical reaction that occurs when external circuit 40 is closed (connecting 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 at negative electrode 22 by reactions such as the oxidation of lithium intercalation to move towards positive electrode 24 via external circuit 40. Lithium ions also generated at negative electrode 22 simultaneously move towards positive electrode 24 via electrolyte 30 contained in separator 26. Electrons flow through external circuit 40 and lithium ions migrate through separator 26 containing electrolyte 30 to form lithium intercalation at positive electrode 24. As described above, electrolyte 30 is also typically present in negative electrode 22 and positive electrode 24. The current 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.

[0086] Battery pack 20 can be charged or recharged at any time by connecting an external power source to lithium-ion battery pack 20 to reverse the electrochemical reactions that occur during battery pack discharge. Connecting an external power source to battery pack 20 promotes a reaction at positive electrode 24, such as the non-spontaneous oxidation of lithium intercalation to generate electrons and lithium ions. Lithium ions flow back to negative electrode 22 via electrolyte 30 through separator 26 to replenish negative electrode 22 with lithium (e.g., lithium intercalation) for use during the next battery pack discharge event. Thus, a complete discharge event followed by a complete charge event is considered a cycle in which lithium ions circulate between positive electrode 24 and negative electrode 22. The external power source that can be used to charge battery pack 20 may vary depending on the size, construction, and specific end use of battery pack 20. Some well-known 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 socket.

[0087] In many lithium-ion battery pack configurations, the negative electrode current collector 32, negative electrode 22, separator 26, positive electrode 24, and positive electrode current collector 34 are each prepared as relatively thin layers (e.g., a few micrometers to a fraction of a millimeter or less thick) and assembled as layers connected in an electrically parallel arrangement to provide suitable electrical energy and power packs. In various aspects, the battery pack 20 may also include a variety of other components known to those skilled in the art, although not depicted herein. For example, the battery pack 20 may include a housing, gaskets, end caps, tabs, battery pack terminals, and any other conventional components or materials that may be located within the battery pack 20, including those located between or near 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, which may include solid-state electrolytes and / or solid-state electroactive particles with different designs known to those skilled in the art.

[0088] As described above, the size and shape of the battery pack 20 can vary depending on the specific application it is designed for. Battery packs powering vehicles and handheld consumer electronics are two examples, where the battery pack 20 is most likely designed with different sizes, capacities, and power output specifications. If required by the load device 42, 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. Accordingly, the battery pack 20 can generate current to the load device 42, which is part of the external circuit 40. The load device 42 can be powered by the current flowing through the external circuit 40 when the battery pack 20 is discharging. While the electrical load device 42 can be many known electric devices, several specific examples include electric motors in electric vehicles, laptops, tablets, mobile phones, and cordless power tools or appliances. The load device 42 can also be a power generation device that charges the battery pack 20 to store electrical energy.

[0089] Re-reference Figure 1 The positive electrode 24, negative electrode 22, and separator 26 may each include an electrolyte solution or system 30 within their pores 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 30 solutions can be used in the lithium-ion battery pack 20.

[0090] In some respects, electrolyte 30 may be a non-aqueous liquid electrolyte solution containing 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 difluorooxalateborate (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.

[0091] These and other similar lithium salts can be dissolved in a variety of non-aqueous, non-protic organic solvents, including but not limited to various alkyl carbonates such as cyclic carbonates (e.g., ethylene carbonate (EC), propylene carbonate (PC), butyl carbonate (BC), fluoroethylene carbonate (FEC)), linear carbonates (e.g., dimethyl carbonate (DMC), diethyl carbonate (DEC), methyl ethyl carbonate (EMC)), aliphatic carboxylic acid esters (e.g., methyl formate, methyl acetate, methyl propionate), γ-lactones (e.g., γ-butyrolactone, γ-valerolactone), chain ethers (e.g., 1,2-dimethoxyethane, 1,2-diethoxyethane, ethoxymethoxyethane), cyclic ethers (e.g., tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxolane), sulfur compounds (e.g., sulfolane), and combinations thereof.

[0092] The porous separator 26 may, in some cases, 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 exhibit any copolymer chain arrangement, including 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, available from Celgard LLC. ® 2500 (single-layer polypropylene spacer) and CELGARD ® 2320 (Three-layer polypropylene / polyethylene / polypropylene separator).

[0093] In some aspects, the spacer 26 may further include one or more ceramic coatings and heat-resistant material coatings. The ceramic coating and / or 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.

[0094] When the spacer 26 is a microporous polymer spacer, it can be a single-layer or multi-layer laminated material, 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 opposite surfaces and can have an average thickness of, for example, less than 1 mm. However, as another example, multiple discrete layers of similar or different polyolefins can be assembled to form the microporous polymer spacer 26. In addition to polyolefins, the spacer 26 may also contain other polymers, 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 establishing the desired porous structure. The polyolefin layer and any other optional polymer layer may be further included as fibrous layers in the spacer 26 to help provide the spacer 26 with appropriate structural and porosity characteristics. 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 comprise alumina (Al2O3), silicon dioxide (SiO2), titanium dioxide (TiO2), or a combination thereof. Various conventionally available polymers and commodities are envisioned for forming the spacer 26, as well as numerous manufacturing methods that can be used to produce such microporous polymer spacers 26.

[0095] In various aspects, Figure 1 The porous separator 26 and electrolyte 30 can be replaced by a solid electrolyte (“SSE”) (not shown) that serves as both the electrolyte and the 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 the negative electrode 22 and the positive electrode 24 and providing electrical insulation between them. As a non-limiting example, the solid electrolyte may include LiTi2(PO4)3, LiGe2(PO4)3, or Li7La3Zr2O. 12 Li3xLa 2 / 3 -xTiO3, Li3PO4, Li3N, Li4GeS4, Li 10 GeP2S 12 , Li2S-P2S5, Li6PS5Cl, Li6PS5Br, Li6PS5I, Li3OCl, Li2.99 Ba 0.005 ClO or a combination thereof.

[0096] The positive electrode 24 can be formed of a lithium-based active material (or in the case of a sodium ion battery pack, a sodium-based active material) capable of undergoing lithium insertion / extraction, alloying and dealloying, or plating and stripping while serving as the positive terminal of the battery pack 20. The positive electrode 24 can be defined by a plurality of electroactive material particles (not shown), and the electroactive material particles are arranged in one or more layers to define the three-dimensional structure of the positive electrode 24. The electrolyte 30 can be introduced, for example, after the battery is assembled and contained within the pores (not shown) of the positive electrode 24. For example, the positive electrode 24 can include a plurality of electrolyte particles (not shown).

[0097] An exemplary common type of known material that can be used to form the positive electrode 24 is a layered lithium transition metal oxide. For example, in some aspects, the positive electrode 24 can include 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 having a layered structure, such as lithium cobalt oxide (LiCoO2), lithium nickel manganese cobalt oxide (Li(Ni 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 a lithium iron polyanion oxide having an olivine structure, such as lithium iron phosphate (LiFePO4), lithium manganese iron phosphate (LiMn 2-x Fe x PO4, where 0 < x < 0.3) or lithium iron fluorophosphate (Li2FePO4F).

[0098] In some variations, the positively active material may optionally be blended with a conductive material that provides an electronic 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 slurry-cast together with such binders, such as polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), ethylene propylene diene monomer (EPDM) rubber or carboxymethyl cellulose (CMC), nitrile 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 (such as KETCHEN), etc. 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.

[0099] The positive electrode 24 may comprise more than or equal to about 80% by weight to less than or equal to about 99% by weight of a positively active material, more than or equal to about 0% by weight to less than or equal to about 15% by weight of an electronically conductive material, and more than or equal to about 0% by weight to less than or equal to about 15% by weight, and in some aspects, optionally more than or equal to about 0% by weight to less than or equal to about 15% by weight of the at least one polymeric binder.

[0100] The negative electrode 22 comprises a lithium host material capable of serving as the negative terminal of a lithium-ion battery pack. For example, the negative electrode 22 may comprise a lithium host material (e.g., a negatively active material) capable of serving as the negative terminal of the battery pack 20. In various aspects, the negative electrode 22 may be defined by a plurality of negatively active material particles (not shown). Such negatively active material particles may be arranged in one or more layers to define the three-dimensional structure of the negative electrode 22. The electrolyte 30 may be introduced, for example, after battery assembly and contained within the pores (not shown) of the negative electrode 22. For example, the negative electrode 22 may comprise a plurality of electrolyte particles (not shown).

[0101] The negative electrode 22 contains an electroactive material as a lithium host material capable of serving as the negative terminal of a lithium-ion battery pack. For example, in various aspects, the negative electroactive material may be a silicon-based electroactive material, and in further variations, the negative electroactive material may contain a combination of silicon and graphite.

[0102] As discussed above, during discharge, the negative electrode 22 may contain a high concentration of intercalated lithium, which is oxidized into lithium ions and electrons. Lithium ions can be transferred from the negative electrode 22 to the positive electrode 24, for example, through the ion-conducting electrolyte 30 contained within the pores of the inserted porous separator 26. Simultaneously, electrons are transferred from the negative electrode 22 to the positive electrode 24 via the external circuit 40. Such lithium ions can be assimilated into the material of the positive electrode 22 through an electrochemical reduction reaction. After partially or fully discharging its usable capacity, the battery pack 20 can be recharged or regenerated by an external power source, which reverses the electrochemical reactions that occurred during discharge.

[0103] However, in some cases, especially in the case of silicon-containing electroactive materials, due to, for example, conversion reactions during the first cycle and / or the formation of Li on the negative electrode 22 x A portion of the embedded lithium remains with the negative electrode 22 due to the Si and / or solid electrolyte interphase (SEI) layer (not shown), and continuous lithium loss due to, for example, persistent SEI rupture. The SEI layer can form on the surface of the negative electrode (anode) and is typically generated from reaction products of the anode material, electrolyte reduction, and / or lithium-ion reduction. Such permanent loss of lithium ions can lead to a reduction in specific energy and power in the battery pack 20. For example, the battery pack 20 may experience an irreversible capacity loss of greater than or equal to approximately 5% to less than or equal to approximately 30% after the first cycle.

[0104] Lithification, for example, pre-lithiation of the electroactive material (e.g., silicon) before incorporation into the battery pack 20, can compensate for such lithium loss during cycling. For example, a certain amount of lithium pre-lithiation, together with an appropriate negative electrode capacity and / or positive electrode capacity ratio (N / P ratio), can be used to control the electrochemical potential within an appropriate window to improve the cycle stability of the battery pack 20. Pre-lithiation can reduce the potential of the silicon-containing electrode. As a non-limiting example, lithiation of silicon via a direct reaction can be represented as: 4.4 x Li + Si → Li 4.4x Si, where 0 ≤ x ≤ 1, while for the electrochemical lithiation of silicon, it can be expressed as 4.4. x Li + + 4.4 x e – +Si → Li 4.4x Si. In each case, the stored lithium can compensate for lithium lost during cycling, including during the first cycle, to reduce capacity loss over time.

[0105] However, common lithiation methods, such as electrochemical, direct contact, and lamination methods, typically require half-cell fabrication and disassembly and / or high-temperature chemical processes. Furthermore, controlling the degree of lithiation occurring during these processes is difficult. In addition, these processes often involve highly reactive chemicals and require additional manufacturing steps. These can be time-consuming and potentially expensive processes. Moreover, such processes often produce materials that are difficult to handle, such as anodes with undesirable thicknesses. This disclosure provides improved pre-lithiated negatively active materials and methods for their formation that can help address these challenges.

[0106] For example, according to various aspects of this disclosure, the silicon-based electroactive material may be a pre-lithiated electroactive material 122 comprising silicon alloy powder, said 122 comprising a plurality of materials with a composition of Li 4.4x Si x M y The basic spherical particles 124, wherein x is greater than 0 to less than or equal to about 0.85, M is at least one of aluminum (Al), chromium (Cr), titanium (Ti), niobium (Nb), molybdenum (Mo), zirconium (Zr), yttrium (Y) and cerium (Ce), and y corresponds to a weight percentage of M greater than or equal to 0.1 wt% to less than or equal to about 10 wt%.

[0107] The basic spherical particle 124 may have an average diameter (D50) of less than or equal to about 40 µm, optionally less than or equal to about 20 µm, optionally less than or equal to about 10 µm, and optionally less than or equal to about 5 µm in some respects. For example, the average diameter (D50) of the basic spherical particle 124 may be greater than or equal to about 1 μm to less than or equal to about 40 μm, greater than or equal to about 1 μm to less than or equal to about 20 μm, and optionally greater than or equal to about 1 μm to less than or equal to about 10 μm in some respects.

[0108] The passivation of the at least one additional metal (M) of the basic spherical particle 124, for example, upon exposure to oxygen or nitrogen, can form a passivation surface film or passivation layer 126 on the surface of the basic spherical particle 124 to form a passivation surface film or passivation layer 126. Figure 2 The core-shell structure is shown. For example, the passivation layer 126 can be a continuous, dense coating comprising oxides (e.g., Al2O3), silicides (e.g., Ti5Si3), nitrides, or mixtures thereof. The passivation layer 126 prevents lithium-silicon alloy particles from reacting with oxygen, moisture (e.g., H2O), organic solvents (e.g., N-methyl-2-pyrrolidone (NMP)), etc., thereby improving the safety of lithium-silicon alloy particles during manufacturing and transportation, as well as electrode manufacturing processes, while achieving high lithium-ion (Li) content. + )diffusion.

[0109] Re-reference Figure 1In some variations, the negatively active material in the negative electrode 22 may optionally be blended with one or more conductive materials that provide electronic 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 blended with binders such as polyimide, polyamic acid, polyamide, polysulfone, polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), ethylene propylene diene monomer (EPDM) rubber or carboxymethyl cellulose (CMC), nitrile 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 (such as KETCHEN), etc. 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.

[0110] The negative electrode 22 may comprise from about 10% to about 99% by weight of a silicon-based electroactive material, from about 0% to about 20% by weight of an electronically conductive material, and from about 0% to about 20% by weight, and optionally, in some aspects, from about 1% to about 20% by weight of the at least one polymeric binder. In some variations, the negative electrode 22 may also comprise from about 0% to about 89% by weight of a graphite-active material.

[0111] In various aspects, this disclosure provides for the manufacture of negative electrodes, such as Figure 1 The method for manufacturing a pre-lithiated silicon-based electroactive material for the negative electrode 22 shown herein. For example, this disclosure contemplates a method for manufacturing a pre-lithiated silicon-based electroactive material using a centrifugal / gas atomization process. In centrifugal atomization processing, molten material is directed to at least one rotating disk or cup, where droplets are formed and they fly away from the rotating disk or cup to solidify and form spherical particles. Thus, in some aspects, the method includes forming a precursor (containing, for example, silicon, lithium, and an additional metal (M)), and centrifugally distributing the precursor by contacting it with a rotating surface in a centrifugal atomization reactor and solidifying the precursor to form a plurality of substantially spherical electroactive particles comprising an alloy of lithium and silicon and having a D50 diameter of less than or equal to about 20 micrometers (μm).

[0112] Figure 3This illustrates an exemplary method for forming a precursor comprising, for example, silicon, lithium, and an additional metal (M), wherein the additional metal (M) is at least one of aluminum (Al), chromium (Cr), titanium (Ti), niobium (Nb), molybdenum (Mo), zirconium (Zr), yttrium (Y), and cerium (Ce). As shown in Table 1, eutectic mixing of silicon and lithium is typically difficult using conventional methods, for example, because silicon's melting temperature is higher than lithium's boiling point, resulting in undesirable lithium evaporation, and because silicon's density is much higher than lithium's, resulting in gravitational separation, such as floating molten lithium blocks.

[0113] Material <![CDATA[Density (g / cm 3 )]]> Melting point (°C | K) Boiling point (°C | K) Li 0.534 180.5 │453.7 1342 │1603 Si 2.329 1414 │1687 3265 │3538

[0114] Table 1. Comparison of material properties.

[0115] This disclosure provides a method for forming a precursor comprising, for example, silicon, lithium, and an additional metal (M), wherein the additional metal (M) is at least one of aluminum (Al), chromium (Cr), titanium (Ti), niobium (Nb), molybdenum (Mo), zirconium (Zr), yttrium (Y), and cerium (Ce), which minimizes gravity separation and lithium evaporation during the centrifugation step and improves alloy uniformity and reduces processing time. In some variations, this disclosure uses a collision mixing method to form the precursor.

[0116] like Figure 3 As shown, the impact method 200 includes a lithium source or feeder 210 and a silicon feeder 220. The lithium feeder 210 includes molten lithium. The silicon source or feeder 220 includes molten silicon. The lithium feeder 210 may have an internal temperature higher than the melting temperature of lithium. The silicon feeder 220 may have an internal temperature lower than the boiling point of silicon. The lithium feeder 210 may have an internal pressure greater than or equal to about 10 PSI, optionally greater than or equal to about 20 PSI, and in some respects optionally greater than or equal to about 50 PSI. The lithium feeder 210 may have an internal pressure less than or equal to about 4000 PSI. The silicon feeder 220 may have an internal pressure greater than or equal to about 10 PSI, optionally greater than or equal to about 20 PSI, and in some respects optionally greater than or equal to about 50 PSI. The silicon feeder 220 may have an internal pressure less than or equal to about 4000 PSI.

[0117] Molten lithium travels from lithium feeder 210 to mixing chamber 250. For example, molten lithium travels from lithium feeder 210 to mixing chamber 250 via supply line 212. Molten silicon travels from silicon feeder 220 to mixing chamber 250. For example, molten silicon travels from silicon feeder 220 to mixing chamber 250 via supply line 222. For example, silicon feeder 220 may have an internal temperature less than or equal to approximately 1600°C. Mixing chamber 250 may be an hermetically sealed mixing chamber. Mixing chamber 250 may have an internal temperature less than the boiling point temperature of silicon.

[0118] Molten lithium may have a first temperature. Molten silicon may have a second temperature. The second temperature may be higher than the first temperature. For example, the first temperature may be greater than or equal to about 180.5°C (the melting point of lithium) to less than or equal to about 1342°C (the boiling point of lithium). The second temperature may be greater than or equal to about 1414°C (the melting point of silicon) to less than or equal to about 3265°C (the boiling point of silicon). When the lower-temperature lithium melt encounters the higher-temperature silicon melt in the mixing chamber 250, a portion of the silicon melt solidifies to form a semi-liquid mixture in which solid silicon particles are surrounded by (dispersed within) the mixture of molten lithium and silicon. The particle size of the solid silicon particles depends on nucleation factors, including the cooling rate (i.e., the temperature difference between the molten lithium and molten silicon entering the mixing chamber) and the mass ratio (i.e., the amount of molten lithium and molten silicon entering the mixing chamber per unit time). For example, the solid silicon particles have an average particle size greater than or equal to about 1 nm to less than or equal to about 1 mm. In this case, the contact area between solid silicon particles and molten lithium is improved to improve the melting efficiency of silicon.

[0119] Mixing occurs in an argon-based environment within mixing chamber 250. Mixing takes place in a closed system to ensure all lithium (evaporated or unevaporated) participates in the mixing reaction. Furthermore, the mixture temperature is regulated to minimize lithium evaporation. The semi-liquid mixture is cooled within mixing chamber 250, and the solid precursor 59 is removed from mixing chamber 250. Excess lithium travels from mixing chamber 250 to lithium feeder 210 via return line 214.

[0120] In some cases, the method further utilizes one or more metering pumps 216, 226. This can be based on the target mixture (e.g., Li). 4.4x Si, where 0 ≤ x ≤ 1), selects the rate at which silicon and lithium meet, and the respective flow rates through lithium supply line 212 and silicon supply line 222. For example, a first metering pump 216 may be arranged downstream of lithium supplier 210 and upstream of mixing chamber 250. Supply line 212 may lead to and exit the first metering pump 216. A second metering pump 226 may be arranged downstream of silicon supplier 220 and upstream of mixing chamber 250. Supply line 222 may lead to and exit the second metering pump 226. In each case, metering pumps 216 and 226 may be used to define the pressure and rate at which the respective materials enter mixing chamber 250. In some cases, as a non-limiting example, lithium may enter mixing chamber 250 at a rate of approximately 15 g / s, and silicon may enter mixing chamber 250 at a rate of approximately 28 g / s to form Li. 2.2 Si.

[0121] Figure 4An exemplary centrifugal atomizing reactor 50 is shown. It should be noted that reactor 50 is a simplified form and may include various other devices and components. A suitable multi-stage centrifugal atomizing reactor for forming a number of electroactive particles is described in U.S. Patent Application 16 / 681,321, filed November 12, 2019, entitled “Article for Producing Ultra-Fine Powders and Method of Manufacture Thereof,” the relevant portions of which are incorporated herein by reference. For example, using... Figure 3 The precursor 59 prepared by the collision process 200 shown can be conveyed in batches or continuously from the upstream furnace (where the molten precursor 60 is formed) and introduced into a distribution vessel or tundish 62. In various respects, an additional metal (M) is added to the precursor 59 to form a molten precursor 60 containing the additional metal (M). The additional metal can be a pure metal or a metal hydride (MH). x The precursor 60 contains at least one of aluminum (Al), chromium (Cr), titanium (Ti), niobium (Nb), molybdenum (Mo), zirconium (Zr), yttrium (Y), and cerium (Ce). In each case, the molten precursor 60 may have a temperature greater than or equal to about 800°C and less than or equal to about 1000°C.

[0122] The casting plate 62 has at least one outlet orifice 64 with a suitable diameter to facilitate the rapid discharge of the molten precursor material 60. As those skilled in the art will recognize, the number and diameter of the outlet orifices 64 can be adjusted during and after atomization to control particle size. Furthermore, the casting plate 62 may be rotatable or have a pressure source to enhance discharge through the outlet orifice 64. A stream 66 of the molten precursor material 60 is discharged from the outlet orifice 64. The molten precursor material 60 comprises silicon, lithium, and an additional metal (M). For example, the molten precursor material 60 includes Li. 4.4x Si x M y The composition of the substance is, wherein x is greater than 0 to less than or equal to about 0.85, M is at least one of aluminum (Al), chromium (Cr), titanium (Ti), niobium (Nb), molybdenum (Mo), zirconium (Zr), yttrium (Y) and cerium (Ce), and y corresponds to a weight percentage of M greater than or equal to 0.1 wt% to less than or equal to about 10 wt%.

[0123] Material 66 contacts the surface 76 of a rotating assembly 70, which may be in the form of a disc or a cup. The rotating assembly 70 is rotatably connected to a shaft 72 and a motor 74. Rotational motion is transmitted from the motor 74 to the rotating assembly 70 via the shaft 72. The rotational motion of the rotating assembly 70 applies centrifugal force to the molten precursor material 60, causing it to distribute and pulverize in the reactor 50 from the central axis defined by the shaft 72 outwards in a centrifugal direction 78. As shown, the molten precursor material 60 contacts the rotating surface 76 and forms droplets 80 as it is conveyed outwards, which solidify to form a plurality of substantially spherical solid electroactive particles 82.

[0124] Although not shown, in various respects, the rotating component 70 includes one or more metallic coatings, wherein each metallic coating comprises gold (Au), aluminum (Al), silver (Ag), etc. Each metallic coating may have a thickness greater than or equal to about 0.01 µm to less than or equal to about 0.1 µm. Such coatings improve the wettability of the molten precursor material 60 to reduce the thickness of the layer of molten precursor material 60 disposed on the rotating component 70 in the centrifugal direction 78. The reduction in the thickness of the layer of molten precursor material 60 disposed on the rotating component 70 in the centrifugal direction 78 reduces the particle size of the substantially spherical solid electroactive particles 82.

[0125] Furthermore, although not shown, ultrasonic or mechanical vibrations can be applied to the rotating assembly 70 to promote the pulverization of the molten precursor material 60 and the deagglomeration of the particles. Microdroplets 80 are ejected outwards. Solid particles 82 are ejected outwards towards the wall 84 of the reactor 50, and then fall into the outlet region 86, which includes the outlet 88. The ultrafine solid particles 82 are transported to the outlet 88 under gravity. As shown, a collection container 90 is connected to the outlet 88 and collects the particles 82. In some variations, although not shown, but as those skilled in the art will recognize, the outlet 88 may alternatively be in fluid communication with an additional reactor chamber, for example, for the vapor-phase coating of electroactive material particles.

[0126] The solidified particles formed by such methods may be relatively small (e.g., fine or ultrafine) and have a substantially circular shape. "Substantially circular" includes particles with a low aspect ratio and a morphology or shape including spheres, circles, spheroidal shapes, ovals, ellipses, etc. In some variations, the particle has a spherical shape. Furthermore, the solid particle may have an average diameter (D50). The average diameter (D50) refers to the cumulative 50% point (or 50% through particle size) of the diameters of a plurality of solid particles. In some aspects, the average diameter (D50) of the plurality of electroactive solid particles formed by centrifugal atomization is less than or equal to about 40 μm, optionally less than or equal to about 20 μm, optionally less than or equal to about 10 μm, and in some aspects optionally less than or equal to about 5 μm. For example, the average diameter (D50) of the plurality of electroactive solid particles formed may be greater than or equal to about 1 μm to less than or equal to about 20 μm, and in some aspects optionally greater than or equal to about 1 μm to less than or equal to about 10 μm.

[0127] The plurality of electroactive solid particles formed by centrifugal atomization can be relatively monodisperse, for example, having a narrow polydispersity index or particle size variation among the formed plurality of particles. In one aspect, the particle size distribution is narrow, having a polydispersity index of less than or equal to about 1.2. In some aspects, centrifugal atomization of the plurality of electroactive materials can provide high yields for a target or predetermined particle size range. For example, if the average particle size (D50) is selected to be greater than or equal to about 1 μm to less than or equal to about 20 μm, the total yield of solid particles with a predetermined particle size range from this method can be greater than or equal to about 10% to less than or equal to about 90%. These uniform diameter electroactive materials formed from alloys of lithium and silicon can be used in a variety of electrochemical batteries / battery packs and energy storage devices, such as Figure 1 The negative electrode 22 and battery pack 20 are shown.

[0128] In some variations, the environment within the centrifugal atomizing reactor may be substantially free of gaseous oxygen-containing substances to avoid reaction with lithium. For example, the environment may contain less than or equal to about 0.5% by weight of any oxygen-containing substances in the gas phase, such as oxygen, water, etc. The reactor environment may optionally have a low water / humidity content, manifested as a relative humidity (RH) of less than or equal to 0.5% at the reaction condition temperature.

[0129] Centrifugal atomizing reactors can achieve high throughput in the formation of particles of electroactive materials with desired average particle size ranges, for example, with mass flow rates greater than or equal to 50 kg / h to less than or equal to approximately 500 kg / h. Higher flow rates are also possible, provided the formed particles have the desired average particle size (D50). Flow rate affects particle size. For example, the higher the flow rate of the molten material, the larger the particle size produced. Therefore, the flow rate may be limited by the desired particle size.

[0130] In some aspects, the temperature in the centrifugal atomizing reactor during the centrifugal distribution of the molten precursor can be greater than or equal to 400°C to less than or equal to about 1,000°C. Higher temperatures may help reduce viscosity and improve film breakdown during the centrifugal atomization process. In some variations, the temperature in the centrifugal atomizing reactor during the centrifugal distribution of the molten precursor can be greater than or equal to 400°C to less than or equal to about 800°C. Compared to other pre-lithiation methods, the centrifugal / gas atomization provided by certain aspects of this disclosure offers a means of precisely controlling the degree of pre-lithiation and the phase formed.

[0131] Therefore, centrifugal / gas atomization reactors are used in various applications to produce particles containing pre-lithiated silicon-based electroactive materials. Such centrifugal / gas atomization reactors provide high throughput production of particles containing pre-lithiated silicon-based electroactive materials with a relatively uniform particle size distribution and high yields of predetermined average particle sizes. Pre-lithiated silicon-based electroactive materials include Li... 4.4x Si x M y The composition of the substance is, wherein x is greater than 0 to less than or equal to about 0.85, M is at least one of aluminum (Al), chromium (Cr), titanium (Ti), niobium (Nb), molybdenum (Mo), zirconium (Zr), yttrium (Y) and cerium (Ce), and y corresponds to a weight percentage of M greater than or equal to 0.1 wt% to less than or equal to about 10 wt%.

[0132] Such pre-lithiated silicon-based electroactive materials reduce lithium consumption and initial stress during formation cycling. The benefit lies in the initial volume expansion (e.g., approximately 300%) of the silicon-containing electroactive material due to lithiation before incorporation into the electrode, enhancing the mechanical properties of the initially formed electrode. Conventionally, silicon-containing electroactive materials are incorporated into the electrode (e.g., mixed with a polymer matrix and other electrode components) and then lithiated, where initial expansion occurs. This expansion during lithiation can cause mechanical stress and potential damage not only to the electroactive particles but also to the surrounding composite material. When electroactive materials are formed from lithium-silicon alloys according to this technology, the materials have already undergone initial volume expansion (e.g., approximately 300%), thus incorporating them into the electrode results in less expansion and contraction stress (e.g., approximately 200%) during lithium cycling.

[0133] By using such Figure 4 The centrifugal atomization reactor shown illustrates a method for fabricating electrodes by mixing particles containing pre-lithiated silicon-based electroactive materials with a polymer binder compound, a non-aqueous solvent, an optional plasticizer, and optional conductive particles to form a slurry. Figure 1 The negative electrode 22 is shown. The slurry can be mixed or stirred and then thinly applied to a substrate, for example, using a doctor blade. The substrate can be a removable substrate or a functional substrate, such as a current collector (e.g., a metal mesh or screen layer) attached to one side of the electrode film. In one variant, heat or radiation can be applied to evaporate the solvent from the electrode film, leaving a solid residue. The electrode film can be further solidified, in which heat and pressure are applied to the film to sinter and calender it. In other variants, the film can be air-dried at a moderate temperature to form a self-supporting film. If the substrate is removable, it is subsequently removed from the electrode film, and then the electrode film is further laminated onto the current collector. For either type of substrate, any residual plasticizers may have to be extracted or removed before being incorporated into the battery pack.

[0134] Lithium-ion battery packs incorporating pre-lithiated silicon-based electroactive materials prepared according to this disclosure, such as Figure 1 The battery pack 20 shown maintains a charging capacity (e.g., operating within a preselected range or other target high-capacity applications) of at least approximately 1,000 hours of battery pack operation, optionally greater than or equal to approximately 1,500 hours of battery pack operation, optionally greater than or equal to approximately 2,500 hours or longer of battery pack operation, and in some respects, optionally greater than or equal to approximately 5,000 hours or longer (active cycling).

[0135] In some aspects, lithium-ion battery packs incorporating pre-lithiated silicon-based electroactive materials prepared according to this disclosure maintain their charge capacity and thus operate at 20% of their target charge capacity for a duration of greater than or equal to about 2 years (including storage under ambient conditions and active cycling time), optionally greater than or equal to about 3 years, optionally greater than or equal to about 4 years, optionally greater than or equal to about 5 years, optionally greater than or equal to about 6 years, optionally greater than or equal to about 7 years, optionally greater than or equal to about 8 years, optionally greater than or equal to about 9 years, and in some aspects, optionally greater than or equal to about 10 years.

[0136] In other aspects, lithium-ion battery packs incorporating pre-lithiated silicon-based electroactive materials prepared according to this disclosure are capable of operating for durations of at least about 100 deep discharge cycles, at least about 200 deep discharge cycles, at least about 500 deep discharge cycles, or at least about 1,000 deep discharge cycles, with a change of less than or equal to about 30% in the preselected target charge capacity (and thus with extremely low charge capacity decay), optionally at least about 20%, optionally at least about 15%, optionally at least about 10%, and in some variations, optionally at least about 5% in charge capacity variation.

[0137] In other words, in some aspects, lithium-ion battery packs or electrochemical cells incorporating pre-lithiated silicon-based electroactive materials prepared according to this disclosure maintain charge capacity and are capable of operating for at least about 1,000 deep discharge cycles, optionally greater than or equal to about 2,000 deep discharge cycles, optionally greater than or equal to about 3,000 deep discharge cycles, optionally greater than or equal to about 4,000 deep discharge cycles, and in some variations, optionally greater than or equal to about 5,000 deep discharge cycles.

[0138] The above description of the embodiments is provided for illustrative and descriptive purposes. It is not intended to be exhaustive or limiting of this disclosure. Elements or features of a particular embodiment are generally not limited to that particular embodiment, but are interchangeable and applicable to selected embodiments, if applicable, even if not explicitly shown or described. It can also be changed in many ways. Such changes should not be considered a departure from this disclosure, and all such modifications are intended to be included within the scope of this disclosure.

Claims

1. A method of manufacturing a negative electrode material for an electrochemical cell for cycling lithium ions, the method comprising: contacting a precursor comprising silicon, lithium, and a metal (M) selected from chromium (Cr), niobium (Nb), molybdenum (Mo), zirconium (Zr), yttrium (Y), cerium (Ce), and combinations thereof, with a rotating surface in a centrifugal atomization reactor and solidifying the precursor to form a plurality of substantially circular solid electroactive particles comprising Li 4.4x Si x M y wherein x is greater than 0 to less than or equal to 0.85 and y corresponds to a weight percent of M greater than or equal to 0.1 wt% to less than or equal to 10 wt%, wherein the rotating surface comprises one or more metal coatings, wherein each metal coating comprises one or more of gold (Au), aluminum (Al), and silver (Ag) and has a thickness greater than or equal to 0.01 pm to less than or equal to 0.1 pm.

2. The method of claim 1, further comprising, for each substantially circular solid electroactive particle of the plurality of substantially circular solid electroactive particles, passivating a metal (M) to form a passivation coating on an exposed surface of each substantially circular solid electroactive particle.

3. The method of claim 2, wherein the method further comprises: passivating the metal (M) comprises exposing the plurality of substantially circular solid electroactive particles to oxygen or nitrogen.

4. The method of claim 1, wherein during the contacting, a temperature in the centrifugal atomization reactor is greater than or equal to 400 °C to less than or equal to 1,000 °C.

5. The method of claim 1, wherein an environment in the centrifugal atomization reactor has less than or equal to 0.5 wt% of any oxygen-containing species.

6. The method of claim 1, wherein a flow rate of the centrifugal atomization reactor is greater than or equal to 50 kg / hr to less than or equal to 500 kg / hr.

7. The method of claim 1, wherein an average D50 diameter of the plurality of substantially circular solid electroactive particles is greater than or equal to 1 pm to less than or equal to 20 pm, and the plurality of substantially circular solid electroactive particles have a polydispersity index of less than or equal to 1.

2.

8. The method of claim 1, wherein the method further comprises: preparing the precursor, wherein preparing the precursor comprises: forming the mixture by contacting a first material comprising lithium having a first temperature and a second material comprising silicon having a second temperature in a mixing chamber to form a first mixture, wherein the first material and the second material each enter the mixing chamber at a pressure greater than or equal to 10 PSI, and the second temperature is higher than the first temperature.

9. The method of claim 8, wherein the first temperature is equal to or higher than a melting point temperature of lithium, and the second temperature is equal to or higher than a melting point temperature of silicon.

10. The method of claim 8, wherein the contacting occurs by using a first feed line to introduce lithium from a lithium source into the mixing chamber and a second feed line to introduce silicon from a silicon source into the mixing chamber, and wherein the first feed line comprises a first metering pump and the second feed line comprises a second metering pump, the first metering pump controls a pressure and a rate of lithium into the mixing chamber, the second metering pump controls a pressure and a rate of silicon into the mixing chamber.

11. The method of claim 10, wherein the method further comprises: removing the mixture from the mixing chamber, adding a metal (M) to the mixture, and heating the mixture and the metal (M) to form the precursor.

12. A method of manufacturing a negative electrode material for an electrochemical cell for cycling lithium ions, the method comprising: contacting a first material comprising lithium and having a first temperature and a second material comprising silicon and having a second temperature in a mixing chamber to form a precursor, wherein the first material and the second material each enter the mixing chamber at a pressure greater than or equal to 10 PSI, and the first temperature is equal to or higher than a melting point temperature of lithium, the second temperature is equal to or higher than a melting point temperature of silicon; adding a metal (M) selected from chromium (Cr), niobium (Nb), molybdenum (Mo), zirconium (Zr), yttrium (Y), cerium (Ce), and combinations to the precursor and heating the precursor and metal (M) to form a molten precursor; and by centrifugally distributing the molten precursor and solidifying the molten precursor to form a plurality of substantially circular solid electroactive particles comprising Li 4.4x Si x M y wherein x is greater than 0 to less than or equal to 0.85 and y corresponds to a weight percent of M greater than or equal to 0.1 wt% to less than or equal to 10 wt% and has an average D50 diameter of less than or equal to 20 microns, wherein the rotating surface comprises one or more metal coatings, wherein each metal coating comprises one or more of gold (Au), aluminum (Al), and silver (Ag), and each metal coating has a thickness of greater than or equal to 0.01 pm to less than or equal to 0.1 pm.

13. The method of claim 12, wherein the method further comprises, for each substantially circular solid electroactive particle of the plurality of substantially circular solid electroactive particles, passivating the metal (M) to form a passivation coating on an exposed surface of each substantially circular solid electroactive particle.

14. The method of claim 13, wherein passivating the metal (M) comprises exposing the plurality of substantially circular solid electroactive particles to oxygen or nitrogen.

15. The method of claim 12, wherein the contacting occurs by introducing lithium from a lithium source into the mixing chamber using a first feed line and introducing silicon from a silicon source into the mixing chamber using a second feed line, and the method further comprises removing the precursor from the mixing chamber.

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