METHOD FOR THE FORMATION OF LITHIUM-SILICIUM ALLOYS FOR ELECTROCHEMICAL CELLS

Abstract

A method for producing an electroactive material for an electrochemical cell, the method comprising: Bringing into contact a first mixture comprising lithium and having a first temperature with a second mixture comprising silicon and having a second temperature in a mixing chamber to form a precursor, wherein the first mixture and the second mixture each enter the mixing chamber at a pressure greater than or equal to approximately 10 PSI and the second temperature is greater than the first temperature; and centrifugal distribution of the precursor by bringing the precursor into contact with a rotating surface in a centrifugal sputtering reactor and solidifying the precursor to form a variety of essentially round solid electroactive particles comprising an alloy of lithium and silicon and having a D50 diameter of less than or equal to approximately 30 micrometers.

Description

INTRODUCTION

[0001] This section contains background information related to the present disclosure that does not necessarily represent the prior art.

[0002] There is a need for advanced energy storage devices and systems to meet the energy and / or power requirements of a wide variety of products, including automotive products such as start-stop systems (e.g., 12V start-stop systems), battery-powered systems, hybrid electric vehicles (HEVs), and electric vehicles (EVs). Typical lithium-ion batteries comprise at least two electrodes and an electrolyte and / or separator. One of the two electrodes can serve as the positive electrode or cathode, and the other as the negative electrode or anode. A separator and / or electrolyte can be placed between the negative and positive electrodes. The electrolyte is capable of conducting 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 batteries, which include solid-state electrodes and a solid-state electrolyte, the solid-state electrolyte can physically separate the electrodes, so that a separate separator is not required.

[0003] Conventional rechargeable lithium-ion batteries function by reversibly transferring lithium ions back and forth between the negative and positive electrodes. For example, during charging, lithium ions move from the positive electrode to the negative electrode, and during discharging, they move in the opposite direction. Such lithium-ion batteries can reversibly supply power to an associated load device as needed. Specifically, a load device can be powered by the lithium-ion battery until the lithium content of the negative electrode is effectively depleted. The battery can then be recharged by passing a suitable direct current in the opposite direction between the electrodes.

[0004] During discharge, the negative electrode can contain a relatively high concentration of intercalated lithium, which is oxidized to lithium ions and electrons. Lithium ions can migrate from the negative electrode to the positive electrode, for example, through the ionically conductive electrolyte solution contained in the pores of an intermediate porous separator. Simultaneously, electrons migrate from the negative electrode to the positive electrode through an external circuit. These lithium ions can be incorporated into the material of the positive electrode through an electrochemical reduction reaction. After a partial or complete discharge of its available capacity, the battery can be recharged or regenerated by an external power source, thereby reversing the electrochemical reactions that occurred during discharge.

[0005] In some cases, however, a portion of the intercalated lithium remains at the negative electrode after the first cycle, for example, due to conversion reactions and / or the formation of a solid electrolyte interlayer (SEI) on the negative electrode during the first cycle, as well as ongoing lithium loss, such as from continuous SEI rupture. Such a persistent loss of lithium ions can lead to reduced specific energy and power in the battery, resulting, for example, from the additional mass of the positive electrode, which does not participate in the battery's reversible operation.For example, after the first cycle, a lithium-ion battery may experience an irreversible capacity loss of approximately 5% to 30% or greater, and silicon-containing negative electrodes may experience an irreversible capacity loss of approximately 20% to 40% or greater after the first cycle. Accordingly, it would be desirable to develop improved electrodes and electroactive materials, as well as methods for their fabrication and use, that can overcome these challenges. State-of-the-art information can be found in US 2020 / 0 194 776 A1, US 2015 / 0 380 733 A1, and Cloud, Jacqueline E., et al., “Lithium silicide nanocrystals: Synthesis, chemical stability, thermal stability, and carbon encapsulation.” In: Inorganic Chemistry 53.20 (2014): 11289–11297. SUMMARY

[0006] This section contains a general summary of the revelation and is not a comprehensive revelation of its full scope or all of its features.

[0007] The present disclosure relates to a process for producing a precursor material based on lithiated silicon, which can be used to form a negative electroactive material for use in an electrochemical cell, and to a process for producing the negative electroactive material using the precursor based on lithiated silicon.

[0008] In several aspects, the present disclosure provides a method for producing an electroactive material for an electrochemical cell. The method comprises bringing into contact a first mixture containing lithium and having a first temperature with a second mixture containing silicon and having a second temperature in a mixing chamber to form a precursor. The first mixture and the second mixture can each enter the mixing chamber at a pressure greater than or equal to approximately 10 PSI. The second temperature is higher than the first temperature. The method can further comprise centrifugally dispersing the precursor by bringing the precursor into contact with a rotating surface in a centrifugal sputtering reactor and solidifying the precursor to form a plurality of substantially round solid electroactive particles.The solid electroactive particles comprise alloys of lithium and silicon and can have D50 diameters of less than or equal to approximately 30 micrometers.

[0009] In one aspect, the first temperature may be equal to or greater than the melting point of lithium, and the second temperature may be equal to or greater than the melting point of silicon.

[0010] For one aspect, the first temperature can be greater than or equal to approximately 180.5 °C to less than or equal to approximately 1342 °C, and the second temperature can be greater than or equal to approximately 1414 °C to less than or equal to approximately 3265 °C.

[0011] In one aspect, contact is achieved by moving lithium from a lithium source to the mixing chamber using a first supply line and moving silicon from a silicon source to the mixing chamber using a second supply line.

[0012] In one configuration, the first supply line can include a first metering pump, and the second supply line can include a second metering pump. The first metering pump can control the pressure and speed at which the lithium enters the mixing chamber. The second metering pump can control the pressure and speed at which the silicon enters.

[0013] In one aspect, the process may further include removing the precursor from the mixing chamber and heating the precursor to form a molten precursor that is centrifugally dispersed.

[0014] In one aspect, the alloy can be described by the formula Li 4,4 ,Si are represented where x is greater than 0 but less than or equal to approximately 0.85.

[0015] In one aspect, the alloy can include a phase selected from the group consisting of Li 22 Si5, Li 13Si4, Li7Si3, Li 12 Si7, LiSi, Si and combinations thereof.

[0016] In one aspect, the temperature in the centrifugal atomization reactor during centrifugal distribution can be greater than or equal to 400 °C to less than or equal to approximately 1,000 °C.

[0017] In one aspect, the environment in the centrifugal atomization reactor may contain less than or equal to approximately 0.5 wt% of an oxygen-containing species.

[0018] In one aspect, the flow rate of the centrifugal atomization reactor can be greater than or equal to 50 kg / h to less than or equal to approximately 500 kg / h.

[0019] In one aspect, the D50 diameter can be greater than or equal to approximately 1 µm to less than or equal to approximately 20 µm, and the multitude of essentially round solid electroactive particles can have a polydispersity index of less than or equal to approximately 1.2.

[0020] In one aspect, the rotating surface comprises one or more gold coatings having a thickness of approximately 0.01 µm or greater than or equal to approximately 0.1 µm.

[0021] In various aspects, the present disclosure provides a method for producing a precursor for an electroactive material for use in an electrochemical cell. The precursor comprises silicon and lithium. The method involves contacting a first mixture comprising lithium and having a first temperature with a second mixture comprising silicon and having a second temperature in a mixing chamber to form a precursor. The first mixture and the second mixture can each enter the mixing chamber at a pressure greater than or equal to approximately 10 PSI. The second temperature can be higher than the first temperature.

[0022] In one aspect, the first temperature can be equal to or greater than the melting temperature of lithium, and the second temperature can be equal to or greater than the melting temperature of silicon.

[0023] For one aspect, the first temperature can be greater than or equal to approximately 180.5 °C to less than or equal to approximately 1342 °C, and the second temperature can be greater than or equal to approximately 1414 °C to less than or equal to approximately 3265 °C.

[0024] In one aspect, contact is achieved by moving lithium from a lithium source to the mixing chamber using a first supply line and moving silicon from a silicon source to the mixing chamber using a second supply line.

[0025] In one configuration, the first supply line can include a first metering pump, and the second supply line can include a second metering pump. The first metering pump can control the pressure and rate at which the lithium enters the mixing chamber, and the second metering pump can control the pressure and rate at which the silicon enters.

[0026] In one aspect, the process may also include the removal of the precursor from the mixing chamber.

[0027] Further applications arise from the description given herein. The description and specific examples in this summary serve only for illustration and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings described herein serve only to illustrate selected embodiments and not all possible versions, and are not intended to limit the scope of the present disclosure. Fig. Figure 1 shows a schematic representation of an exemplary electrochemical battery cell. Fig. Figure 2 shows an exemplary impact mixing process according to various aspects of current technology. Fig. Figure 3 shows an exemplary centrifugal sputtering reactor used according to current technology to form ultrafine electroactive material particles for use in an electrochemical battery cell, as in Fig. 1 illustrates.

[0029] Corresponding reference symbols identify corresponding parts in the different views of the drawings. DETAILED DESCRIPTION

[0030] Since exemplary embodiments are provided, this is a careful disclosure that conveys the full scope to those skilled in the art. Numerous specific details are listed, such as examples of specific compositions, components, devices, and processes, to provide a comprehensive understanding of the embodiments of this disclosure. It is obvious to those skilled in the art that specific details need not be used, that exemplary embodiments can be embodied in many different forms, and that none of them should be interpreted in such a way as to limit the scope of the disclosure. In some exemplary embodiments, known processes, known device structures, and known technologies are not described in detail.

[0031] The terminology used herein serves only to describe certain exemplary configurations and is not intended to be restrictive. As used herein, the singular forms "ein," "eine," and "der," "die," "das" can also include the plural forms unless the context clearly indicates otherwise. The terms "umfassen," "umfassend," "haltten," and "aufweisen" are inclusive and therefore specify the presence of indicated features, elements, compositions, steps, integers, processes, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, processes, elements, components, and / or groups thereof.Although the open term "comprehensive" is to be understood as a non-restrictive term that serves to describe and claim various embodiments set forth herein, the term can alternatively be understood as a more restrictive term in certain aspects, such as "consisting of" or "essentially consisting of". Therefore, for each given embodiment that specifies compositions, materials, components, elements, features, integers, processes and / or process steps, the present disclosure expressly includes embodiments that consist of or essentially consist of such specified compositions, materials, components, elements, features, integers, processes and / or process steps.In the case of "consisting of", the alternative configuration excludes all additional compositions, materials, components, elements, features, integers, operations and / or process steps, whereas in the case of "essentially consisting of", all additional compositions, materials, components, elements, features, integers, operations and / or process steps that significantly affect the basic and novel properties are excluded from such a configuration, but all compositions, materials, components, elements, features, integers, operations and / or process steps that do not significantly affect the basic and novel properties may be included in the configuration.

[0032] All procedures, processes, and operations described herein are not to be interpreted as necessarily having to be carried out in the specific order explained or illustrated, unless they are expressly designated as such. It is also understood that additional or alternative steps may be applied unless otherwise specified.

[0033] When a component, element, or layer is described as being "on" or "interacting with" another element or layer, or as being "connected" or "coupled" to it, it may be directly on or interacting with, or connected or coupled to, the other component, element, or layer, or there may be intervening elements or layers. Conversely, when an element is described as being "directly on" or "directly interacting with" another element or layer, or as being "directly connected" or "directly coupled" to it, there must be no intervening elements or layers. Other words used to describe the relationship between elements should be interpreted similarly (e.g.,“Between” as opposed to “directly between”, “neighboring” or “adjacent” as opposed to “directly adjacent” or “directly bordering”, etc.). As used herein, the term “and / or” includes all combinations of one or more of the related listed items.

[0034] Although the terms first, second, third, etc., may be used herein to describe different steps, elements, components, areas, layers, and / or sections, these steps, elements, components, areas, layers, and / or sections should not be restricted by these terms unless otherwise specified. These terms should only be used to distinguish one step, element, component, area, layer, or section from another. Terms such as "first," "second," and other numerical terms, when used herein, do not imply any sequence or order unless the context clearly indicates otherwise.Thus, one could refer to a first step, a first element, a first component, a first area, a first layer or a first section, which will be discussed below, as a second step, second element, second component, second area, second layer or second section, without deviating from the principles of the exemplary embodiments.

[0035] Spatially or temporally relative terms such as "before," "after," "inner," "outer," "below," "under," "lower," "above," "upper," and the like may be used herein for the sake of simplicity to describe the relationship of one element or feature to one or more other elements or features, as illustrated in the figures. Spatially or temporally relative terms may be intended to include, in addition to the orientation shown in the figures, different orientations of the device or system in use or operation.

[0036] Throughout this entire disclosure, numerical values ​​represent approximate measures or limits for ranges to include minor deviations from the stated values ​​and configurations that approximate the stated value, as well as those that exactly match the stated value. Unlike the working examples at the end of the detailed description, all numerical values ​​of parameters (e.g., quantities or conditions) in this patent specification, including the claims in the appendix, are to be understood as being modified in all cases by the term "approximately," regardless of whether "approximately" actually precedes the numerical value or not. "Approximately" means that the stated numerical value permits a slight inaccuracy (with some approximation to the accuracy of the value, approximately or quite close to the value, almost).If the imprecision indicated by "approximately" is not otherwise understood in engineering with this ordinary meaning, then "approximately," as used herein, denotes at least variations that may arise from ordinary procedures for measuring and using such parameters. For example, "approximately" may include a deviation 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 optionally less than or equal to 0.1%.

[0037] Furthermore, the disclosure of ranges includes the disclosure of all values ​​and further subdivided ranges within the entire range, including the endpoints and the sub-ranges specified for the ranges.

[0038] As used herein, the terms “composition” and “material” are used interchangeably to refer generally to a substance which contains at least the preferred chemical constituents, elements or compounds, but which may also contain additional elements, compounds or substances, including traces of impurities, unless otherwise specified.

[0039] Exemplary designs will now be described in more detail with reference to the attached drawings.

[0040] The current technology relates to an electrode material, e.g., a negative electrode material, for use in an electrochemical cell, as well as to methods for its manufacture and use in this context. The electrode material may comprise a silicon-containing electroactive material, and in certain modifications, the electrode material may be pre-lithiated. A method for forming pre-lithiated electroactive material may involve the preparation of a precursor comprising lithium and silicon and the centrifugal dispersal of the precursor using a centrifugal sputtering reactor.

[0041] A typical lithium-ion battery comprises a first electrode (e.g., a positive electrode or cathode) opposite a second electrode (e.g., a negative electrode or anode) and a separator and / or electrolyte between them. In a lithium-ion battery, batteries or cells can often be electrically connected in a stacked or coiled configuration to increase overall power. Lithium-ion batteries function by the reversible flow of lithium ions between the first and second electrodes. For example, lithium ions can move from a positive electrode to a negative electrode during charging and in the opposite direction during discharging. The electrolyte is suitable for conducting lithium ions (or sodium ions in the case of sodium-ion batteries and the like) and can be in liquid, gel, or solid form. For example, in Fig.1 an exemplary and schematic representation of an electrochemical cell (also called a battery) 20 illustrates.

[0042] Such cells are used in vehicle or car transport applications (e.g., motorcycles, boats, tractors, buses, motorhomes, caravans, and tanks). However, current technology can be used in a wide variety of other industries and applications, for example (but not limited to) aerospace components, consumer goods, appliances, buildings (e.g., houses, offices, sheds, and warehouses), office equipment and furniture, as well as machinery for industrial equipment, agricultural equipment, farm machinery, or heavy machinery.Although the illustrated examples include a single cathode and a single anode, the person skilled in the art will recognize that current teachings extend to various other configurations, including those with one or more cathodes and one or more anodes, as well as various current collectors with electroactive layers arranged on one or more surfaces thereof or adjacent to them.

[0043] The battery 20 comprises a negative electrode 22 (e.g., anode), a positive electrode 24 (e.g., cathode), and a separator 26 located between the electrodes 22 and 24. The separator 26 provides electrical isolation between the electrodes 22 and 24, i.e., it prevents physical contact. The separator 26 also provides a minimal resistance path for the internal passage of lithium ions and, in certain cases, related anions during lithium ion cycling. In some configurations, the separator 26 includes an electrolyte 30, which may also be present in both the negative electrode 22 and the positive electrode 24. In certain modifications, the separator 26 may be formed by a solid electrolyte 30. For example, the separator 26 may be defined by a variety of particles of the solid electrolyte (not shown).

[0044] A current collector 32 of the negative electrode can be positioned on or near the negative electrode 22, and a current collector 34 of the positive electrode can be positioned on or near the positive electrode 24. The current collector 32 of the negative electrode can be a metal foil, a metal grid or screen, or expanded metal comprising copper or another suitable electrically conductive material known to those skilled in the art. The current collector 34 of the positive electrode can be a metal foil, a metal grid or screen, or expanded metal comprising aluminum or another suitable electrically conductive material known to those skilled in the art. The current collector 32 of the negative electrode and the current collector 34 of the positive electrode each collect free electrons and move them to and from an external circuit 40.For example, an interruptible external circuit 40 and a load device 42 can connect the negative electrode 22 (via the current collector 32 of the negative electrode) and the positive electrode 24 (via the current collector 34 of the positive electrode).

[0045] The battery 20 can generate an electric current during discharge through reversible electrochemical reactions that occur when the external circuit 40 is closed (to connect the negative electrode 22 and the positive electrode 24) and the negative electrode 22 has a lower potential than the positive electrode. The chemical potential difference between the positive electrode 24 and the negative electrode 22 drives the electrons generated at the negative electrode 22 by a reaction, e.g., the oxidation of intercalated lithium, through the external circuit 40 towards the positive electrode 24. Lithium ions, also generated at the negative electrode 22, are simultaneously transferred to the positive electrode 24 through the electrolyte 30 contained in the separator 26.The electrons flow through the external circuit 40, and the lithium ions migrate across the separator 26, which contains the electrolyte solution 30, to form intercalated lithium at the positive electrode 24. As mentioned above, the electrolyte 30 is also typically present in the negative electrode 22 and the positive electrode 24. The electric current flowing through the external circuit 40 can be utilized and passed through the load device 42 until the lithium in the negative electrode 22 is consumed and the capacity of the battery 20 is reduced.

[0046] The battery 20 can be recharged or re-powered at any time by connecting an external power source to the lithium-ion battery 20 to reverse the electrochemical reactions that occur during battery discharge. Connecting an external electrical power source to the battery 20 promotes a reaction, such as non-spontaneous oxidation of intercalated lithium, at the positive electrode 24, generating electrons and lithium ions. The lithium ions flow back through the electrolyte 30 and via the separator 26 to the negative electrode 22, replenishing the negative electrode 22 with lithium (e.g., intercalated lithium) for use during the next battery discharge cycle. As such, each complete discharge cycle followed by a complete recharge cycle is considered a cycle in which lithium ions are cycled between the positive electrode 24 and the negative electrode 22.The external power source that can be used to charge battery 20 can vary depending on the size, design, and specific end application of battery 20. Some specific and exemplary external power sources include, among others, an AC-to-DC converter connected to an AC power supply via a wall socket and a vehicle alternator.

[0047] In many lithium-ion battery arrangements, the negative electrode current collector 32, the negative electrode 22, the separator 26, the positive electrode 24, and the positive electrode current collector 34 are each manufactured as relatively thin layers (e.g., with a thickness of a few micrometers to a fraction of a millimeter or less) and assembled in electrically parallel layers to obtain a suitable electrical energy and power package. Depending on various aspects, the battery 20 may also include a variety of other components, which, although not shown here, are nevertheless known to those skilled in the art.For example, the battery 20 can comprise a housing, seals, terminal caps, tabs, battery terminals, and all other conventional components or materials located within the battery 20, including between or around the negative electrode 22, the positive electrode 24, and / or the separator 26. The in . Fig. The battery 20 shown comprises a liquid electrolyte 30 and illustrates representative concepts of battery operation. However, current technology also applies to solid-state batteries, which comprise solid electrolytes (and electroactive solid particles) that, as is known to those skilled in the art, may have a different structure.

[0048] As mentioned previously, the size and shape of the battery 20 can vary depending on the specific application for which it is designed. Battery-powered vehicles and portable consumer electronics devices are two examples where the battery 20 would very likely be designed according to different size, capacity, and power specifications. The battery 20 can also be connected in series or parallel with other similar lithium-ion cells or batteries to produce a higher output voltage, energy, and power when required by the load device 42. Accordingly, the battery 20 can generate electrical current for a load device 42 that is part of the external circuit 40. The load device 42 can be powered by the electrical current flowing through the external circuit 40 as the battery 20 discharges.While the electrical load device 42 can be any number of known electrically powered devices, some specific examples include an electric motor for an electric vehicle, a laptop computer, a tablet computer, a mobile phone, and cordless power tools or devices. The load device 42 can also be a power generating device that charges the battery 20 for the purpose of storing electrical energy.

[0049] With renewed reference to Fig.1. The positive electrode 24, the negative electrode 22, and the separator 26 can each comprise an electrolyte solution or electrolyte system 30, for example, in their pores, capable of conducting lithium ions between the negative electrode 22 and the positive electrode 24. Any suitable electrolyte 30, whether in solid, liquid, or gel form, capable of conducting lithium ions between the negative electrode 22 and the positive electrode 24, can be used in the lithium-ion battery 20. In certain aspects, the electrolyte 30 can be a non-aqueous liquid electrolyte solution comprising a lithium salt dissolved in an organic solvent or a mixture of organic solvents. Numerous conventional non-aqueous liquid electrolyte solutions 30 can be used in the lithium-ion battery 20.

[0050] In certain aspects, the electrolyte 30 can be a non-aqueous liquid electrolyte solution comprising one or more lithium salts dissolved in an organic solvent or a mixture of organic solvents. A non-restrictive list of lithium salts that can be dissolved in an organic solvent to form the non-aqueous liquid electrolyte solution includes, for example, lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiCl4), lithium tetrachloroaluminate (LiAlCl4), lithium iodide (LiI), lithium bromide (LiBr), lithium thiocyanate (LiSCN), lithium tetrafluoroborate (LiBF4), lithium tetraphenylborate (LiB(C6H5)4), lithium bis(oxalato)borate (LiB(C2O4)2) (LiBOB), lithium difluorooxalatoborate (LiBF2(C2O4)), lithium hexafluoroarsenate (Li-AsF6), lithium trifluoromethanesulfonate (LiCF3SO3), lithium bis(trifluoromethanesulfonyl)imide (LiN(CF3SO2)2), lithium bis(fluorosulfonyl)imide (LiN(FSO2)2) (LiSFI) and combinations thereof.

[0051] These and other similar lithium salts can be dissolved in a variety of non-aqueous aprotic organic solvents, including various alkyl carbonates, such as... Examples include cyclic carbonates (e.g., ethylene carbonate (EC), propylene carbonate (PC), butylene 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 compounds (e.g., sulfolane), and combinations thereof.

[0052] The porous separator 26 may, in certain cases, comprise a microporous polymeric separator containing a polyolefin. The polyolefin may be a homopolymer (derived from a single monomer component) or a heteropolymer (derived from more than one monomer component), and may be either linear or branched. If a heteropolymer is derived from two monomer components, the polyolefin may adopt any copolymer chain arrangement, including that of a block copolymer or a statistical copolymer. If the polyolefin is a heteropolymer derived from more than two monomer components, it may also be a block copolymer or a statistical copolymer. In certain aspects, the polyolefin may be polyethylene (PE), polypropylene (PP), a mixture of PE and PP, or multilayer structured porous films of PE and / or PP. Commercially available porous polyolefin membranes 26 include CELGARD. ®2500 (single-layer polypropylene separator) and CELGARD ® 2320 (three-layer polypropylene / polyethylene / polypropylene separator), which are available from Celgard LLC.

[0053] In certain aspects, the separator 26 may further comprise a ceramic coating and / or a heat-resistant material coating. The ceramic coating and / or the heat-resistant material coating may be arranged on one or more sides of the separator 26. The material forming the ceramic layer may be selected from the group consisting of aluminum oxide (Al₂O₃), silicon dioxide (SiO₂), and combinations thereof. The heat-resistant material may be selected from the group consisting of Nomex, aramid, and combinations thereof.

[0054] If the separator 26 is a microporous polymer separator, it can be a single-layer or multi-layer laminate that can be produced using either a dry or wet process. For example, in certain cases, a single layer of polyolefin can constitute the entire separator 26. In other cases, the separator 26 can be a fibrous membrane with numerous pores extending between opposing surfaces and, for example, having an average thickness of less than one millimeter. Alternatively, several discrete layers of identical or different polyolefins can be combined to form the microporous polymer separator 26.The separator 26 can comprise other polymers besides the polyolefin, including but not limited to polyethylene terephthalate (PET), polyvinylidene fluoride (PVdF), a polyamide, polyimide, polyamide-polyimide copolymer, polyetherimide, and / or cellulose, or any other material suitable for creating the required porous structure. The polyolefin layer and any other optional polymer layers can also be incorporated into the separator 26 as a fiber layer to contribute to imparting suitable structural and porosity properties. In certain aspects, the separator 26 can be blended with a ceramic material or its surface can be coated with a ceramic material. For example, a ceramic coating can comprise aluminum oxide (Al₂O₃), silicon dioxide (SiO₂), titanium dioxide (TiO₂), or combinations thereof.Various conventionally available polymers and commercial products for the formation of the separator 26 are conceivable, as are the many manufacturing processes that can be used to produce such a microporous polymer separator 26.

[0055] The porous separator 26 and the electrolyte 30 can be used in various aspects. Fig. 1 can be replaced by a solid electrolyte (“SSE”) (not shown) that acts as both an electrolyte and a separator. The solid electrolyte can be positioned between the positive electrode 24 and the negative electrode 22. The solid electrolyte enables the transfer of lithium ions while simultaneously providing mechanical separation and electrical insulation between the negative and positive electrodes 22, 24. As a non-limiting example, solid electrolytes can be LiTi₂(PO₄)₃, LiGe₂(PO₄)₃, Li₇La₃Zr₂O 12 , Li3xLa 2 / 3 -xTiO3, Li3PO4, Li3N, Li4GeS4, Li10 GeP2S 12 , Li2S-P2S5, Li6PS5Cl, Li6PS5Br, Li6PS5l, Li3OCl, Li 2,99 Ba 0,005 ClO or combinations thereof.

[0056] The positive electrode 24 can be formed from a lithium-based (or sodium-based in the case of sodium-ion batteries) active material that can be subjected to lithium / sodium intercalation and deintercalation, alloying and dealloying, or coating and peeling processes while acting as the positive terminal of the battery 20. The positive electrode 24 can be defined by a variety of electroactive material particles (not shown) arranged in one or more layers to define the three-dimensional structure of the positive electrode 24. The electrolyte 30 can, for example, be introduced after the cell is assembled and contained in pores (not shown) of the positive electrode 24. The positive electrode 24 can, for example, comprise a variety of electrolyte particles (not shown).

[0057] An exemplary common class of known materials that can be used to form the positive electrode 24 are layered lithium transition metal oxides. In certain aspects, the positive electrode 24 can, for example, comprise one or more materials with 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) 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 a lithium nickel cobalt metal oxide (LiNi (1-x-y) CO x M yO2, where 0 <x<0,2, y<0,2, und M Al, Mg, Ti oder dergleichen sein kann); oder ein Lithium-Eisen-Polyanion-Oxid mit Olivinstruktur, wie Lithiumeisenphosphat (LiFePO4), Lithiummanganeisenphosphat (LiMn 2-x Fe x PO4, where 0 < x < 0.3) or lithium iron fluorophosphate (Li2FePO4F).

[0058] In certain modifications, the positive electroactive materials can optionally be mixed with an electronically conductive material that provides an electron conduction path, and / or with at least one polymeric binder that improves the structural integrity of the electrode. For example, the positive electroactive materials and electronically or electrically conductive materials can be suspended with binders such as polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), ethylene propylene diene monomer rubber (EPDM), carboxymethylcellulose (CMC), nitrile butadiene rubber (NBR), styrene butadiene rubber (SBR), lithium polyacrylate (LiPAA), sodium polyacrylate (NaPAA), sodium alginate, or lithium alginate. Electrically conductive materials can include carbon-based materials, powdered nickel or other metal particles, or a conductive polymer. Carbon-based materials can include, for example,These include particles made of graphite, acetylene black (such as KETCHEN™ black or DENKA™ black), carbon fibers and nanotubes, graphene, and the like. Examples of conductive polymers include polyaniline, polythiophene, polyacetylene, polypyrrole, and the like. For certain applications, mixtures of conductive materials may be used.

[0059] The negative electrode 22 comprises a lithium host material capable of acting as the negative terminal of a lithium-ion battery. For example, the negative electrode 22 can comprise a lithium host material (e.g., a negative electroactive material) capable of acting as the negative terminal of the battery 20. In various aspects, the negative electrode 22 can be defined by a variety of negative electroactive material particles (not shown). Such negative electroactive material particles can be arranged in one or more layers to define the three-dimensional structure of the negative electrode 22. The electrolyte 30 can, for example, be introduced after the cell has been assembled and be contained in pores (not shown) of the negative electrode 22. The negative electrode 22 can, for example, comprise a variety of electrolyte particles (not shown).

[0060] The negative electrode 22 can comprise a negative electroactive material based on silicon and containing silicon, for example lithium-silicon and silicon-containing binary and ternary alloys and / or tin-containing alloys such as Si-Sn, SiSnFe, SiSnAl, SiFeCo, SnO2 and the like.

[0061] In certain modifications, the negative electroactive material of the negative electrode 22 can optionally be mixed with one or more electrically conductive materials that provide an electron-conducting path, and / or at least one polymeric binder material that improves the structural integrity of the negative electrode 22. For example, the negative electroactive material in the negative electrode 22 can optionally be mixed with binders such as polyimide, polyamic acid, polyamide, polysulfone, polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), ethylene propylene diene monomer rubber (EPDM), carboxymethylcellulose (CMC), nitrile butadiene rubber (NBR), styrene butadiene rubber (SBR), lithium polyacrylate (LiPAA), sodium polyacrylate (NaPAA), sodium alginate, or lithium alginate.Electrically conductive materials can include carbon-based materials, powdered nickel or other metal particles, or a conductive polymer. Carbon-based materials can include, for example, particles of graphite, acetylene black (such as KETCHEN™ black or DENKA™ black), carbon fibers and nanotubes, graphene, and the like. Examples of conductive polymers include polyaniline, polythiophene, polyacetylene, polypyrrole, and the like. In certain applications, mixtures of conductive materials can be used.

[0062] As described above, the negative electrode 22 can contain a comparatively high concentration of intercalated lithium during discharge, which is oxidized to lithium ions and electrons. Lithium ions can migrate from the negative electrode 22 to the positive electrode 24, for example, through the ionically conductive electrolyte 30 contained in the pores of an intermediate porous separator 26. Simultaneously, the electrons traverse an external circuit 40 from the negative electrode 22 to the positive electrode 24. Such lithium ions can be assimilated into the material of the positive electrode 22 by an electrochemical reduction reaction. After a partial or complete discharge of its available capacity, the battery 20 can be recharged or regenerated by an external power source, thereby reversing the electrochemical reactions that took place during discharge.In various cases, particularly with silicon-containing electroactive materials, some of the intercalated lithium remains at the negative electrode 22 after the first cycle, e.g., due to conversion reactions and / or the formation of a solid electrolyte interlayer (SEI) on the negative electrode 22, as well as ongoing lithium loss, e.g., due to continuous rupture of the SEI. This permanent loss of lithium ions can lead to reduced specific energy and power in the battery 20. Current technology provides improved electroactive materials and electrode materials, as well as methods for their fabrication, that can overcome these challenges.

[0063] In various aspects, the battery 20 can be lithiated, for example, to create a lithium reservoir. Electroactive materials (or electrodes containing electroactive materials) can be lithiated prior to electrode formation. In particular, the negative electroactive material (e.g., silicon) can be lithiated prior to the formation of the negative electrode 22. For example, a quantity of pre-lithiated lithium, along with a suitable ratio of negative electrode capacitance and / or positive electrode capacitance (N / P ratio), can be used to control the electrochemical potential within a suitable window to improve the cycle stability of the battery 20. Pre-lithiation can lower the potential for silicon-containing electrodes. As a non-restrictive example, the lithiation of silicon can be expressed by direct reaction as: 4.4xLi + Si → Li 4,4xSi, where 0 ≤ x ≤ 1, while for the electrochemical lithiation of silicon it is 4.4xLi + + 4.4xe -+ Si → Li 4,4x This can be expressed as follows. In any case, the reserved lithium can compensate for the lithium loss during cycling, even during the first cycle, to reduce capacity loss over time.

[0064] In certain aspects, the present disclosure provides methods for the production of negative electrodes containing pre-lithiated electrochemically active negative electrode materials, such as the negative electrode 22 described in Fig.Figure 1 illustrates this. For example, the present disclosure provides a method for producing electroactive materials from lithiated silicon by a centrifugal / gas sputtering process. In centrifugal sputtering, a molten material is directed onto at least one rotating disk or rotating cup, where molten droplets form and fly away from the rotating disk or rotating cup to solidify and form spherical particles.In particular, according to the current technology, the process comprises forming a precursor containing silicon and lithium, and centrifugally dispersing the precursor by contacting it with a rotating surface in a centrifugal sputtering reactor. The precursor solidifies to form a multitude of essentially round electroactive particles comprising a lithium-silicon alloy and having a D50 diameter of less than or equal to approximately 20 micrometers (µm). The alloy can be described by the formula Li. 4,4x Si can be represented where x is greater than 0 but less than or equal to approximately 0.85, and optionally by a formula Li for certain aspects. 4,4x Si, where x is greater than or equal to approximately 0.1 to less than or equal to approximately 0.5. For example, the alloy may include a phase selected from the group consisting of Li 22 Si5, Li 13Si4, Li7Si3, Li 12 Si7, LiSi, Si and combinations thereof. In certain modifications, the centrifugal atomization process forms a multitude of particles with a relatively small particle size (e.g., ultrafine particles) and a smaller particle size distribution (e.g., monodisperse).

[0065] Fig. Figure 2 shows an exemplary process for the formation of a solid-state precursor comprising silicon and lithium. As shown in Table 1, fusing silicon and lithium together using conventional methods can often be difficult, for example, because the melting point of silicon is higher than the boiling point of lithium, resulting in undesirable lithium evaporation, and because the density of silicon is much higher than that of lithium, leading to gravity deposition, e.g., a large lump of molten lithium. Table 1. Comparison of material properties material Density (g / cm³) 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

[0066] The present disclosure provides a process for forming a silicon- and lithium-comprising precursor that minimizes gravity deposition and lithium evaporation during the centrifugal step, improves alloy homogeneity, and reduces processing time. Current technology uses an impact mixing process to form a precursor. As described in Fig.As illustrated in Figure 2, the impact process 200 comprises a lithium source or lithium reservoir 210 and a silicon reservoir 220. The lithium reservoir 210 comprises molten lithium. The silicon source or silicon reservoir 220 comprises molten silicon. The lithium reservoir 210 may have an internal temperature higher than the melting point of lithium. The silicon reservoir 220 may have an internal temperature below the boiling point of silicon. The lithium reservoir 210 may have an internal pressure greater than or equal to approximately 10 PSI, optionally greater than or equal to approximately 20 PSI, and, under certain conditions, optionally greater than or equal to approximately 50 PSI. The lithium reservoir 210 may have an internal pressure less than or equal to approximately 4000 PSI. The silicon 220 supply can have an internal pressure greater than or equal to approximately 10 PSI, optionally greater than or equal to approximately 20 PSI, and in certain aspects optionally greater than or equal to approximately 50 PSI.The silicon supply 220 can have an internal pressure of less than or equal to approximately 4000 PSI.

[0067] The molten lithium migrates from the lithium reservoir 210 towards a mixing chamber 250. The molten lithium reaches the mixing chamber 250, for example, via a supply line 212. The molten silicon migrates from the silicon reservoir 220 towards the mixing chamber 250. The molten silicon reaches the mixing chamber 250, for example, via a supply line 222. The silicon reservoir 220 can have an internal temperature of approximately 1600 °C or less. The mixing chamber 250 can be airtight. The mixing chamber 250 can have an internal temperature lower than the boiling point of silicon.

[0068] The molten lithium has a first temperature. The molten silicon has a second temperature. The second temperature is higher than the first. The first temperature can be, for example, greater than or equal to approximately 180.5 °C (i.e., the melting point of lithium) to less than or equal to approximately 1342 °C (i.e., the boiling point of lithium). The second temperature can be greater than or equal to approximately 1414 °C (i.e., the melting point of silicon) to less than or equal to approximately 3265 °C (i.e., the boiling point of silicon). When the lower-temperature molten lithium comes into contact with the higher-temperature molten silicon in mixing chamber 250, some of the molten silicon solidifies, creating a semi-liquid mixture in which solid silicon particles are surrounded (dispersed) by a mixture of molten lithium and silicon.The particle size of the solid silicon particles depends on nucleation factors, which include the cooling rate (i.e., the temperature difference between the molten lithium and the molten silicon entering the mixing chamber) and the mass unit 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 diameter of approximately 1 nm to approximately 1 mm. In such cases, the contact area between the solid silicon particles and the molten lithium is improved, thus increasing the melting efficiency of the silicon.

[0069] Mixing takes place in mixing chamber 250 in an argon-based environment. The mixing process occurs in a closed system, ensuring that all lithium (whether evaporated or not) participates in the mixing reaction. Furthermore, the temperature of the mixture is adjusted to minimize lithium evaporation. The semi-liquid mixture is cooled in mixing chamber 250, and the solid precursor 59 is extracted from the mixing chamber. Excess lithium migrates from mixing chamber 250 via return line 214 to the lithium reservoir 210.

[0070] In certain cases, the method also uses one or more metering pumps 216, 226. The speed at which the silicon and lithium meet, as well as the flow rates through the lithium supply line 212 and the silicon supply line 222, can each be adjusted based on the desired mixture (e.g., Li). 4,4xSi, where 0 ≤ x ≤ 1) are selected. For example, a first metering pump 216 can be located downstream of the lithium reservoir 210 and upstream of the mixing chamber 250. The supply line 212 can lead to and from the first metering pump 216. A second metering pump 226 can be located downstream of the silicon reservoir 220 and upstream of the mixing chamber 250. The supply line 222 can lead to and from the second metering pump 226. In each case, the metering pumps 216 and 226 can be used to define the pressure and velocity at which the respective materials enter the mixing chamber 250. In certain cases, for example (non-limiting), lithium can enter the mixing chamber 250 at a rate of approximately 15 grams / second, and silicon can enter the mixing chamber 250 at a rate of approximately 28 grams / second, so that Li 2,2 Si is formed.

[0071] Fig. Figure 3 shows an exemplary centrifugal atomization reactor 50. It should be noted that reactor 50 is a simplified version and may include various other devices. A suitable multi-stage centrifugal atomization reactor capable of producing the multitude of electroactive particles is described in U.S. Patent Application No. 16 / 681,321, filed on November 12, 2019, entitled "Article for Producing Ultra-Fine Powders and Method of Manufacture Thereof," the relevant parts of which are incorporated herein by reference. A precursor 59, which, for example, is combined with the one described in Fig.The product, which is manufactured by the impact process 200 illustrated in Figure 2, can be conveyed batchwise or continuously from an upstream furnace in which a molten precursor 60 is formed and introduced into a distributor vessel or distributor 62. The molten precursor 60 can have a temperature of approximately 800 °C or higher to approximately 1000 °C or lower.

[0072] The distributor 62 has at least one outlet opening 64 with a suitable diameter to allow rapid discharge of the precursor material 60. The number and diameter of the outlet openings 64 can be adjusted to control the particle size during and after the atomization process, as is known among those skilled in the art. Furthermore, the distributor 62 can rotate or have a pressure source to improve discharge through the outlet opening 64. A stream 66 of molten precursor material 60 is discharged from the outlet opening 64.

[0073] The current 66 touches a surface 76 of a rotating component 70, which may be in the form of a disk or a cup. The rotating component 70 is in rotational connection with a shaft 72 and a motor 74. The rotational motion is transmitted from the motor 74 to the rotating component 70 via the shaft 72. The rotation of the component 70 exerts a centrifugal force on the molten precursor material 60, causing it to be distributed and pulverized in a centrifugal direction 78 outwards from the central axis defined by the shaft 72 within the reactor 50. As shown, the molten precursor material 60 comes into contact with the rotating surface 76 and, as it passes through in an outward direction, forms droplets 80 that solidify and constitute a multitude of essentially round, solid, electroactive particles 82.In certain cases, not shown here, the rotating surface 76 can optionally be coated with gold, for example with a thickness of approximately 0.01 µm to approximately 0.1 µm. Such a gold coating can improve the wettability of the molten precursor material 60 on the rotating surface 76.

[0074] Furthermore, the rotating component 70 can be subjected to ultrasound or mechanical vibration to enable the pulverization of the molten material and the deagglomeration of particles (not shown). The droplets 80 are ejected outwards. The solid particles 82 are propelled outwards against a wall 84 of the reactor 50 and then fall into an outlet area 86, which includes an outlet 88. The ultrafine solid particles 82 are transported to the outlet 88 by gravity. As shown, a collection container 90 is connected to the outlet 88, which collects the particles 82; however, in certain modifications, which are not shown, the outlet 88 can alternatively be in fluidic communication with additional reactor chambers, e.g., for the gas-phase coating of particles made of electroactive material.

[0075] The solidified particles formed by such a process can be relatively small (e.g., fine or ultrafine) and have an essentially round shape. "Essentially round" includes particles with low aspect ratios and a morphology or shape that includes spherical, rounded, globular, ovoid, elliptical, and the like. In certain variations, the particles have a spherical shape. Furthermore, the solid particles can have an average diameter (D). D50 represents a cumulative 50th percentile of the diameter (or 50th percentile particle size) for the multitude of solid particles. In certain aspects, the D50 value of the multitude of electroactive solid particles formed by a centrifugal atomization process is less than or equal to approximately 30 µm, optionally less than or equal to approximately 25 µm, optionally less than or equal to approximately 10 µm, and optionally less than or equal to approximately 5 µm.For certain aspects, the D50 value for the multitude of formed electroactive solid particles can be greater than or equal to approximately 1 µm to less than or equal to approximately 30 µm, and for certain aspects optionally greater than or equal to approximately 1 µm to less than or equal to approximately 20 µm.

[0076] The multitude of electroactive solid particles formed by a centrifugal atomization process can be relatively monodisperse, for example, with a narrow polydispersity index or a wide dispersion of particle sizes among the many particles produced. In one instance, the particle distribution is narrow and exhibits a polydispersity index of approximately 1.2 or less. Under certain conditions, the centrifugal atomization process can provide a high yield for the target or specified particle size diameter range when forming a multitude of electroactive materials. For example, if an average particle diameter greater than or equal to approximately 1 µm to less than or equal to approximately 20 µm is chosen, the overall yield from the process for solid particles within the specified size range can be greater than or equal to approximately 10% to less than or equal to approximately 90%.These electroactive materials with a uniform diameter, formed from an alloy of lithium and silicon, can be used in various electrochemical cells / batteries and energy storage devices, such as in the negative electrode 22 and the battery 20, which are in . Fig. 1 are illustrated.

[0077] In certain modifications, the environment within the centrifugal sputtering reactor can be essentially free of gaseous oxygen-containing species to prevent reaction with lithium. For example, the environment may contain less than or equal to approximately 0.5 wt% of an oxygen-containing species in a gas phase, such as oxygen gas, water, and the like. The reactor environment optionally has a low water / humidity content, reflected in a relative humidity (RH) of less than or equal to 0.5% at the reaction conditions.

[0078] The centrifugal atomization reactor is capable of high throughput, e.g., a mass throughput of ≥ 50 kg / h to ≥ approximately 500 kg / h, when forming particles from electroactive materials with the desired range of average particle sizes. Higher flow rates are also possible as long as the formed particles have the desired D50 value. The flow rate influences the particle size. For example, the higher the flow rate of the molten material, the larger the resulting particles. Thus, the flow rate can be limited by the desired particle size.

[0079] In certain aspects, the alloy formed after the centrifugal sputtering process can comprise one or more of the following phases: Li 22 Si5, Li 13 Si4, Li7Si3, Li 12Si7, LiSi, and Si. In particular, certain modifications where a lower amount of lithium is present in the alloy may contain a phase consisting solely of Si. In certain modifications, the alloy may include one or more of the following phases: Li 22 Si5, Li 13 Si4, Li7Si3, Li 12Si7 and LiSi. As is known among experts, it can be desirable to maximize a relative stoichiometric amount of lithium in the lithium-silicon alloy / electroactive material. In certain aspects, the temperature in the centrifugal sputtering reactor during the centrifugal distribution of a molten precursor can be greater than or equal to 400 °C to less than or equal to approximately 1,000 °C. Higher temperatures can help to reduce viscosity and improve film dissolution during the centrifugal sputtering process. In certain modifications, the temperature in the centrifugal sputtering reactor during the centrifugal distribution of a molten precursor can be greater than or equal to 400 °C to less than or equal to approximately 800 °C.In comparison to other prelithiation methods, centrifugal / gas atomization, as provided for by certain aspects of the present disclosure, provides a means for precise control of the extent of prelithiation and the phases formed.

[0080] In various aspects, a centrifugal / gas atomization reactor is used to produce particles comprising pre-lithiated silicon alloys. Such a centrifugal / gas atomization reactor provides high-throughput production of electroactive lithium-silicon alloy particles with a relatively homogeneous size distribution and thus a high yield for a given average particle size diameter. The Li 4,4xSi alloying can reduce lithium consumption and initial stress during formation cycles. This has the advantage that the electroactive material, which includes silicon, undergoes initial volumetric expansion due to lithiation before being incorporated into an electrode, thus improving the mechanical properties of the initially formed electrode. Conventionally, the electroactive material, which includes silicon, is incorporated into an electrode (e.g., mixed with the polymer matrix and other electrode components) and then lithiated, at which point the initial expansion occurs. This expansion during lithiation can lead to 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 and silicon alloys according to current technology, the materials have already undergone an initial volumetric expansion, so that incorporation into an electrode causes only minimal expansion and contraction stresses during lithium cycling.

[0081] An electrode, e.g. the negative electrode 22, which is in Fig. As illustrated in Figure 1, this can be achieved by mixing the electroactive material, such as a coated lithium-silicon alloy containing powders or particles, using an exemplary centrifugal sputtering reactor, such as the one described in Figure 1. Fig.As illustrated in Figure 3, the electrode film is prepared as a slurry containing a polymeric binder compound, a non-aqueous solvent, optionally a plasticizer, and optionally (if required) electrically conductive particles. The slurry can be mixed or stirred and then applied thinly to a substrate, for example, using a doctor blade. The substrate can be removable or, alternatively, a functional substrate, such as a current collector (e.g., a metallic grid or mesh layer) attached to one side of the electrode film. In a modification, 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 by applying heat and pressure to the film to sinter and calender it.In other variations, the film can be air-dried at a moderate temperature to form self-supporting films. If it is a removable substrate, it is removed from the electrode film, which is then laminated onto a current collector. With both types of substrates, it may be necessary to extract or remove any remaining plasticizer before installation in the battery cell.

[0082] A lithium-ion battery, such as the one in Fig.1. An illustrated battery 20, which contains a negative electroactive material, having an electroactive material made of a lithium-silicon alloy produced according to current technology, maintains a charge capacity (e.g., within a preselected range or other desired high-capacity use) for battery operation of at least approximately 1,000 hours, optionally for battery operation of approximately 1,500 hours or more, optionally for battery operation of approximately 2,500 hours or more, and, in certain aspects, optionally for battery operation of approximately 5,000 hours or more (active cycling).

[0083] Under certain conditions, the lithium-ion battery, which contains a negative electroactive material made of a lithium-silicon alloy produced according to current technology, maintains its charge capacity and is thus able to operate within 20% of its nominal charge capacity for a period of approximately 2 years or more (including storage under ambient conditions and active cycling time), optionally approximately 3 years or more, optionally approximately 4 years or more, optionally approximately 5 years or more, optionally approximately 6 years or more, optionally approximately 7 years or more, optionally approximately 8 years or more, optionally approximately 9 years or more, and optionally approximately 10 years or more under certain conditions.

[0084] In other aspects, the lithium-ion battery, which contains a negative electroactive material with an electroactive material made of a lithium-silicon alloy, manufactured according to current technology, is able to operate with a change of less than or equal to approximately 30% of a preselected target charge capacity (and thus exhibit a minimal charge capacity drop), optionally with less than or equal to approximately 20%, optionally with less than or equal to approximately 15%, optionally with less than or equal to approximately 10%, and with certain modifications optionally with less than or equal to approximately 5% change in charge capacity for a duration of at least approximately 100 deep discharge cycles, optionally at least approximately 200 deep discharge cycles, optionally at least approximately 500 deep discharge cycles, optionally at least approximately 1,000 deep discharge cycles.

[0085] In other words, a lithium-ion battery or electrochemical cell containing a negative electroactive material with an electroactive material made of a lithium-silicon alloy, manufactured according to current technology, maintains its charge capacity under certain conditions and is able to operate for at least approximately 1,000 deep discharge cycles, optionally greater than or equal to approximately 2,000 deep discharge cycles, optionally greater than or equal to approximately 3,000 deep discharge cycles, optionally greater than or equal to approximately 4,000 deep discharge cycles, and, with certain modifications, optionally greater than or equal to approximately 5,000 deep discharge cycles.

[0086] The foregoing description of the embodiments serves for illustration and description purposes. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not restricted to that particular embodiment, but are optionally interchangeable and may be used in a selected embodiment even if they are not specifically shown or described. They may also be modified in many ways. Such modifications are not to be considered a departure from the disclosure, and all such modifications are intended to be contained within the scope of the disclosure.

Claims

[1] Method for producing an electroactive material for an electrochemical cell, the method comprising: Bringing into contact a first mixture comprising lithium and having a first temperature with a second mixture comprising silicon and having a second temperature in a mixing chamber to form a precursor, wherein the first mixture and the second mixture each enter the mixing chamber at a pressure greater than or equal to approximately 10 PSI and the second temperature is greater than the first temperature; and centrifugal distribution of the precursor by bringing the precursor into contact with a rotating surface in a centrifugal sputtering reactor and solidifying the precursor to form a variety of essentially round solid electroactive particles comprising an alloy of lithium and silicon and having a D50 diameter of less than or equal to approximately 30 micrometers. [2] Method according to claim 1, wherein the first temperature corresponds to or is greater than the melting temperature of lithium, and the second temperature corresponds to or is greater than the melting temperature of silicon. [3] Method according to claim 1, wherein the first temperature is greater than or equal to approximately 180.5 °C to less than or equal to approximately 1342 °C and the second temperature is greater than or equal to approximately 1414 °C to less than or equal to approximately 3265 °C. [4] Method according to claim 1, wherein the contacting is carried out by moving lithium from a lithium source to the mixing chamber using a first supply line and moving silicon from a silicon source to the mixing chamber using a second supply line. [5] Method according to claim 4, wherein the first supply line comprises a first metering pump and the second supply line comprises a second metering pump, wherein the first metering pump controls the pressure and speed at which the lithium enters the mixing chamber, and the second metering pump controls the pressure and speed at which the silicon enters. [6] The method of claim 4, wherein the method further comprises removing the precursor from the mixing chamber and heating the precursor to form a molten precursor that is centrifugally dispersed. [7] Method according to claim 1, wherein the alloy is defined by a formula Li 4,4x Si is represented where x is greater than 0 but less than or equal to approximately 0.

85. [8] Method according to claim 1, wherein the alloy comprises a phase selected from the group consisting of Li 22 Si5, Li 13 Si4, Li7Si3, Li12 Si7, LiSi, Si and combinations thereof. [9] Method according to claim 1, wherein the temperature in the centrifugal atomizing reactor during centrifugal distribution is greater than or equal to 400 °C to less than or equal to approximately 1,000 °C, wherein the environment in the centrifugal atomizing reactor contains less than or equal to approximately 0.5 wt.% of an oxygen-containing species, and the flow rate of the centrifugal atomizing reactor is greater than or equal to 50 kg / h to less than or equal to approximately 500 kg / h. [10] Method according to claim 1, wherein the rotating surface comprises one or more gold coatings having a thickness of greater than or equal to approximately 0.01 µm to less than or equal to approximately 0.1 µm.

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