Silicon anode materials and methods of making and using the same

Abstract

Anode materials and anodes and batteries using the same, and methods of manufacturing the same are disclosed. In one exemplary aspect, a method of manufacturing an anode material can include providing a plurality of core structures, each core structure including at least one silicon particle; and performing a plurality of coating and thermal treating steps. The plurality of coating and thermal treating steps can include coating at least a portion of the plurality of core structures with a first sol-gel solution and thermal treating the at least partially coated core structures to produce a plurality of core-shell structures, the first sol-gel solution including vanadium oxide, and coating at least a portion of the plurality of core-shell structures with a second sol-gel solution and thermal treating the at least partially coated plurality of core-shell structures to produce a plurality of multilayered core-shell structures, the second sol-gel solution including vanadium oxide.

Description

Atty. Docket No.: 037866-734001WO SILICON ANODE MATERIALS AND METHODS OF MAKING AND USING THE SAME CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority to U.S. Provisional Patent Application No. 63 / 591,505, filed October 19, 2023, and entitled “SILICON COMPOSITE ANODE MATERIAL,” the disclosure of which is incorporated by reference herein in its entirety. TECHNICAL FIELD

[0002] Silicon anode materials and their application in electrodes and in batteries are provided. BACKGROUND

[0003] Rechargeable lithium-ion batteries that can be safely charged and discharged at high rates are desirable for electrified transportation, portable electronics, grid storage, and other applications. For lithium-ion rechargeable batteries to meet society’s ever-growing demands in electrical energy storage, novel electrode materials with a high charge-storage capacity are needed.

[0004] Large volume modifications during electrochemical cycling of electrodes in Li- ion batteries often limit successful applications due to stress formation, electrode fracture and delamination from the current collector.

[0005] Silicon is one of the most promising anode materials for lithium-ion batteries due to advantages including the highest known capacity and relatively low working potential. However, the practical implementation of Si anodes suffers from three major problems. First, poor cycle life of silicon materials results from pulverization during the huge volumetric fluctuations (up to 400%) which accompany lithium-ion intercalation and deintercalation. Second, drastic irreversible capacity loss and low coulombic efficiency are caused by mechanical fracture of Si anodes during the alloying / dealloying process. Finally, the solid electrolyte interphase (SEI) breaks as the nanostructure shrinks during silicon delithiation. The exposure of a fresh silicon surface to the electrolyte causes the SEI to keep growing thicker with each charge / discharge cycle. SEI formation and growth consume active lithium and electrolyte materials, leading to capacity fading, higher battery resistance, and poor power density.Atty. Docket No.: 037866-734001WO

[0006] Stable long-term performance of silicon as an anode material is limited due to the enormous volume expansion when a large number of Li atoms are incorporated into the silicon electrode during lithiation. The large volume increase often has the consequence of a decay of specific capacity during cycling that is attributed to stress formation, mechanical fracture, and irreversible side reactions that are invoked by the volume changes. Consequently, the development of Si-based Li-ion batteries faces great challenges due to the volume changes induced by cycling and the correlated capacity fading.

[0007] Accordingly, there remains a need for improved anode materials, and in particular silicon-based anode materials, are needed. SUMMARY

[0008] Aspects of the current subject matter relate to, inter alia, anode materials and electrodes and batteries using the same, and methods of manufacturing anode materials and electrodes and batteries using the same are also disclosed.

[0009] In one exemplary aspect, a method of manufacturing an anode material can include providing a plurality of core structures, each core structure including at least one silicon particle, and performing a plurality of coating and thermal treating steps. The plurality of coating and thermal treating steps include coating at least a portion of the plurality of core structures with a first sol-gel solution and thermal treating the at least partially coated core structures to produce a plurality of core-shell structures, the first sol-gel solution including vanadium oxide, and coating at least a portion of the plurality of core-shell structures with a second sol-gel solution and thermal treating the at least partially coated plurality of core-shell structures to produce a plurality of multilayered core-shell structures, the second sol-gel solution including vanadium oxide.

[0010] Anodes are also disclosed. In one exemplary aspect, an anode includes an anode material made by the foregoing exemplary method.

[0011] Battery cells are also disclosed. In one exemplary aspect, a battery cell includes an anode that includes an anode material made by the foregoing exemplary method.

[0012] Methods of manufacturing a battery cell are also disclosed. In one exemplary aspect, a method of manufacturing a battery cell includes casting a slurry on a negative current collector to form an anode on the negative current collector, stacking a separator onAtty. Docket No.: 037866-734001WO the anode, in which the separator includes an electrolyte, casting a cathode material on a positive current collector to form a cathode on the positive current collector; and stacking the cathode on the separator. The slurry includes an anode material made by the foregoing exemplary method.

[0013] Batteries are also disclosed. In one exemplary aspect, a battery includes one or more battery cells, in which the one or more battery cells each include an anode that includes an anode material made by the foregoing exemplary method.

[0014] Methods of manufacturing a battery are also disclosed. In one exemplary aspect, a method of manufacturing a battery includes providing one or more battery cells made by the foregoing exemplary method.

[0015] It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter of this disclosure are contemplated as being part of the inventive subject matter disclosed herein. It should also be appreciated that terminology explicitly employed herein that also can appear in any disclosure incorporated by reference should be accorded a meaning most consistent with the particular concepts disclosed herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which are incorporated into and constitute a part of this specification, show certain aspects of the subject matter disclosed herein and, together with the description, help explain some of the principles associated with the disclosed aspects. In the drawings:

[0017] FIG.1A is a schematic of an exemplary multilayered core-shell structure, in which such structure includes two coating layers of vanadium oxide, consistent with implementations of the current subject matter.

[0018] FIG.1B is a schematic of an exemplary core structure, an exemplary core-shell structure, and the exemplary multilayered core-shell structure of FIG.1A, consistent with implementations of the current subject matter.Atty. Docket No.: 037866-734001WO

[0019] FIG.2 is schematic of an exemplary manufacturing process of the multilayered core-shell structure of FIG.1A, consistent with implementations of the current subject matter.

[0020] FIG.3A is a schematic of an exemplary core-shell structure, consistent with implementations of the current subject matter.

[0021] FIG.3B is a schematic of an exemplary multilayered core-shell structure that includes a plurality of the core-shells structures of FIG.3A, consistent with implementations of the current subject matter.

[0022] FIG.4 is a schematic of an exemplary multilayered core-shell structure, in which such structure includes an aggregation of two multilayered core-shell structures of FIG.1A, consistent with implementations of the current subject matter.

[0023] FIG.5 is a schematic of an exemplary multilayered core-shell structure, in which such structure includes an aggregation of three multilayered core-shell structures of FIG.3B, consistent with implementations of the current subject matter.

[0024] FIG.6 is schematic of an exemplary manufacturing process of a multilayered core-shell structure, consistent with implementations of the current subject matter.

[0025] FIG.7A is a scanning electron microscopy (SEM) image of an exemplary core structure produced in Example 1.

[0026] FIG.7B is a SEM image of an exemplary core-shell structure produced in Example 3.

[0027] FIG.7C is a SEM image of an exemplary multilayered core-shell structure produced in Example 4.

[0028] FIG.7D is a SEM image of an exemplary multilayered core-shell structure produced in Example 7.

[0029] FIG.8 is a schematic of an exemplary battery cell, consistent with implementations of the current subject matter.

[0030] FIG.9 is a graph illustrating cycle stability of the batteries in Example 8.Atty. Docket No.: 037866-734001WO DETAILED DESCRIPTION

[0031] In the following description, certain specific details are set forth in order to provide a thorough understanding of various aspects. However, one skilled in the art will understand that the disclosure can be practiced without these details. In other instances, well- known structures have not been shown or described in detail to avoid unnecessarily obscuring descriptions of the aspects. Unless the context requires otherwise, throughout the specification and claims which follow, the word “comprise” and variations thereof, such as, “comprises” and “comprising” are to be construed in an open, inclusive sense, that is, as “including, but not limited to.” Further, headings provided herein are for convenience only and do not interpret the scope or meaning of the claimed disclosure.

[0032] Reference throughout this specification to “one aspect” or “an aspect” means a particular feature, structure or characteristic described in connection with the aspect is included in at least one aspect. Thus, the appearances of the phrases “in one aspect” or “in an aspect” in various places throughout this specification are not necessarily all referring to the same aspect. Furthermore, the particular features, structures, or characteristics can be combined in any suitable manner in one or more aspects. Also, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. It should also be noted that the term “or” is generally employed in its sense including “and / or” unless the context clearly dictates otherwise.

[0033] The word “about” when immediately preceding a numerical value means a range of plus or minus 10% of that value, e.g., “about 50” means 45 to 55, “about 25,000” means 22,500 to 27,500, etc. Furthermore, the phrases “less than about” a value or “greater than about” a value should be understood in view of the definition of the term “about” provided herein.

[0034] It is understood that the examples and aspects described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims. All publications, patents, and patent applications cited herein are hereby incorporated by reference in their entirety for all purposes.Atty. Docket No.: 037866-734001WO

[0035] Silicon (Si) holds much promise to increase the energy density of lithium-ion batteries due to silicon’s lithium storage capacity of 4200 mA h / g, a lithium storage capacity ten times greater than that of graphite. Research and development effort has focused on improving Si’s cycle life, which is limited by an associated large volume change coupled with a non-mechanically-compliant solid electrolyte interface (SEI) layer. The SEI layer is a passivation layer formed on the surface of lithium-ion battery anode materials produced by electrolyte decomposition. The quality of the SEI layer plays an important role in the cyclability, rate capacity, irreversible capacity loss, and safety of lithium-ion batteries.

[0036] Existing design criteria for long-life Si anodes are well-established and include maintaining electrical connection to the Si during cycling by limiting particle fracture, as well as minimizing the change of electrochemical interfacial area and the fracture of the SEI layer.

[0037] Current Si anode technology typically employs Si nanostructures to manage volume change without fracture. Si nanoparticles, nanowires, nanotubes, thin films, and porous structures have all demonstrated the ability to mitigate particle fracture. Nanostructures are often assembled into larger particles in order to minimize the contact area with the electrolyte. Otherwise, the high surface area of the nanomaterial exaggerates the SEI formation. In Li||Si half cells, a long cycle life of over 1000 cycles has been demonstrated. In addition to using nanostructures to mitigate fracture, some existing technology limits the specific capacity range (i.e., x in LixSi) to improve cycle life. In addition to the success of Si cycling in half cells, progress has been made in full cells as well when a Si anode is paired with 4 V cathodes. Some cells have been demonstrated with stable cycling for 500–1000 cycles.

[0038] However, during storage, the capacity fade of a Si cell has conventionally been a linear function of lifetime capacity throughput. This linear correlation indicates that the active lithium consumption rate through the battery’s life is constant—the SEI is not effectively passivating. This problem has been observed even when the Si anodes are coated with carbon, despite the fact that graphite is known to be a good passivating material, due to the complex chemistry associated with the SEI layer. The chemical composition of the SEI layer may include a variety of organic species (e.g., organic polymers) and inorganic species (e.g., LiF). The underlying Si structure imposes a mechanical stress on the carbon surface coating, which in turn transmits to the SEI on carbon. Heretofore, continuous fracture and spalling of the SEI may occur, leading to fast capacity fading during storage or cycling.Atty. Docket No.: 037866-734001WO

[0039] The present disclosure is predicated, at least in part, on the use of dense lithium vanadium oxides, which are ionically conductive and electronically conductive, as a protective layer in a long-cycle-life Si anode material. The lithium vanadium oxides are mechanically more robust than carbon and are more impermeable to the electrolyte, if the lithium vanadium oxides are densified. In addition, the polar nature of lithium vanadium oxides also likely makes them adhere to the SEI layer well.

[0040] In addition to the oxide shell material to protect Si, it is desirable to select a Si architecture that allows volume expansion while minimizing the stress applied to the shell. Existing technologies attempt to use a pomegranate-like structure. The secondary particles are usually sealed with a carbon coating to limit electrolyte invasion into the internal pores while conducting Li+ions. However, there are challenges in building the pomegranate structure.

[0041] The present disclosure is predicated, at least in part, on the design of porous core structures with an optimized porosity, to accommodate volume expansion of silicon, while also utilizing the above-mentioned dense lithium vanadium oxides. In some aspects, the presently disclosed technology can be employed to fabricate a plurality of core structures that include at least one silicon particle, and optionally, one or more carbon materials, in which the core structures have built-in porosity, and further fabricate a plurality of multilayered core-shell structures that include two or more coating layers, also referred to herein as shells. Each of the two or more coating layers include at least vanadium oxide. These multilayered core-shell structures, without undergoing lithiation, are referred to herein as “SVO” structures, where S is Si and VO is vanadium oxide.

[0042] In some aspects, the SVO structures undergo lithiation (e.g., electrochemically or chemically) and the resulting multilayered core-shell structures are referred to herein as “SLVO” structures, where S is LixSi (x=0 to 3.75) and “LVO” refers to LiaVbOc when there is no dopant present, and LiaVbOcMdwhen there are one or more dopants present. As such, LVO relates to the anode compositions for Li-ion batteries, such as the anode compositions for Li-ion batteries as disclosed, for example, in U.S. Application No.17 / 048,467, filed April 16, 2020, which is incorporated herein by reference in its entirety. LVO is a recently discovered reversible host for lithium in the potential region between 0 V and 2 V. The built- in porosity accommodates volume expansion of silicon during lithiation. The dense layer features a highly stable interface with the electrolyte, has minimal volume change, and enjoysAtty. Docket No.: 037866-734001WO extremely rapid kinetics, capable of delivering half of its capacity in a few seconds. Compared to carbon, LVO is mechanically strong and serves as a rapid charge-transfer mediator to S.

[0043] As disclosed herein, synthesizing a SVO or SLVO structure is provided by iterative sol-gel coating methods. The iterative sol-gel coating methods disclosed herein allow for precise control over the thickness and morphology of the protective layer (e.g., the VO or LVO), which may result in a high-performance anode with excellent stability and long cycle life. This approach may be easily industrialized and provides a great example of creating new solid-state mediator protective material with a disordered rock salt structure. Furthermore, the iterative sol-gel coating methods disclosed herein can enhance the protective layer's quality by reducing the chance of cracking and delamination. This can be, in some instances, critical because any detachment of the protective layer can result in rapid capacity fading and reduced cycle life. The iterative coating process can promote a low cracking chance, making the protective layer more robust and further improving the anode's performance. As such, the SVO and SLVO structures can be utilized in anode materials for batteries.

[0044] In general, methods of manufacturing an anode material include providing a plurality of core structures and performing a plurality of coating and thermal treating steps, wherein the plurality of coating and thermal treating steps. The plurality of coating and thermal treating steps include coating at least a portion of the plurality of core structures with a first sol-gel solution and thermal treating the at least partially coated core structures to produce a plurality of core-shell structures, and coating at least a portion of the plurality of core-shell structures with a second sol-gel solution and thermal treating the at least partially coated plurality of core-shell structures to produce a plurality of multilayered core-shell structures. It is also contemplated herein that additional coating and thermal treating steps (e.g., 1, 2, 3, 4, etc. iterations) can be carried out on the plurality of multilayered core-shell structures, as discussed in more detail below.

[0045] Each core structure of the plurality of core structures includes at least one silicon particle. In some aspects, at least one core structure of the plurality of core structures can include one silicon particle. In other aspects, at least one core structure of the plurality of core structures can include a mixture of the at least one silicon particle and one or more carbon materials. Non-limiting examples of suitable one or more carbon materials includeAtty. Docket No.: 037866-734001WO single-walled carbon nanotubes, multi-walled carbon nanotubes, carbon fibers, carbon black, graphene, sp structure carbon, sp2 structure carbon, or sp3 structure carbon, vapor-grown carbon fiber, ultra-fine carbon, graphite, or any combination thereof. In either aspect, the step of providing the plurality of core structures can include mixing at least one silicon particle and one or more carbon materials together, in which each core structure includes at least one silicon particle and the one or more carbon materials. Alternatively, the step of providing the plurality of core structures can include coating at least one silicon particle with one or more carbon materials, in which each core structure includes at least one silicon particle and the one or more carbon materials.

[0046] In some aspects, the at least one silicon is present in the core structures in a concentration from about 1 wt. % to 100 wt. % silicon. The at least one silicon particle can be formed of amorphous silicon, polycrystalline silicon, or single-crystalline silicon. The at least one silicon can have an average particle size from about 10 nanometers to about 100 microns, for example. The at least one silicon particle can have a variety of geometries. For example, in some aspects, the particle geometry can include spheres, columns, cubes, cylinders, tubes, wires, sheets, fibers, irregular shapes, or any combination thereof.

[0047] The core structures can have a variety of particle sizes. In some aspects, each core structure of the plurality of core structures can have a particle size from about 0.1 microns to about 100 microns, including all subranges in between. In aspects where one or more of the core structures include one silicon particle, the particle size of each of these one or more core structures can have a particle size from about 0.1 microns to about 10 microns or from about 1 micron to 5 microns. In aspects where one or more of the core structures comprises a mixture of at least one silicon particle and one or more carbon materials, the particle size of each of these one or more core structures can have a particle size from about 1 micron to 100 microns or from about 5 microns to 50 microns.

[0048] In some aspects, each core structure of the plurality of core structures can have a porosity of about 30 % or greater.

[0049] The first sol-gel solution includes vanadium oxide. In some aspects, vanadium oxide can include vanadium pentoxide (V2O5), vanadium dioxide (VO2), vanadium trioxide (V2O3), vanadium monoxide (VO), or any combination thereof. In one aspect, the vanadium oxide can include vanadium pentoxide (V2O5). The vanadium oxide present in the first sol-Atty. Docket No.: 037866-734001WO gel solution can vary. For example, in some aspects, the vanadium oxide can be present in the first sol-gel solution in a first amount from about 1 weight percent to about 90 weight percent, including all the subranges in between. In other aspects, the vanadium oxide can be present in the first sol-gel solution in a first amount from about 1 weight percent to about 30 weight percent or from about 1 weight percent to about 50 weight percent.

[0050] The second sol-gel solution also includes vanadium oxide. In some aspects, vanadium oxide can include vanadium pentoxide (V2O5), vanadium dioxide (VO2), vanadium trioxide (V2O3), vanadium monoxide (VO), or any combination thereof. In one aspect, the vanadium oxide can include vanadium pentoxide (V2O5). In certain aspects, the first sol-gel solution and the second sol-gel solution include the same components, whereas in other aspects, the first sol-gel solution and the second sol-gel solution can include at least one different component. Further, the vanadium oxide present in the second sol-gel solution can vary. For example, in some aspects, the vanadium oxide can be present in the second sol-gel solution in a second amount from about 1 weight percent to about 90 weight percent, including all the subranges in between. In other aspects, the vanadium oxide can be present in the second sol-gel solution in a second amount from about 1 weight percent to about 30 weight percent or from about 1 weight percent to about 50 weight percent.

[0051] In some aspects, the vanadium oxide can be present in the first sol-gel solution in a first amount and the vanadium oxide can be present in the second sol-gel solution in a second amount that is equal to or greater than the first amount. In other aspects, the vanadium oxide can be present in the first sol-gel solution in a first amount and the vanadium oxide can be present in the second sol-gel solution in a second amount that is less than the first amount.

[0052] The core-shell structures can have a variety of particle sizes. In some aspects, each core-shell structure of the plurality of core-shell structures can have a particle size from about 0.1 microns to 100 microns, including all subranges in between. In certain aspects, the particle size can be from about 10 microns to about 50 microns or from about 10 microns to about 20 microns.

[0053] Further, each core-shell structure of the plurality of core-shell structures can have an amount of silicon at an outer-most surface thereof, in which the amount of silicon at the outer-most surface is less than the amount of silicon particles at an outer surface of each coreAtty. Docket No.: 037866-734001WO structure of the plurality of core structures. In some aspects, the amount of silicon at the outer-most surface of each core-shell structure can be about 40 % or less of the total amount of silicon present in the respective core-shell structure. In other aspects, the amount of silicon at the outer-most surface of each core-shell structure can be about 30 % or less or about 20 % or less.

[0054] Each multilayered core-shell structure of the plurality of multilayered core-shell structures can have a variety of particles sizes. For example, in some aspects, each multilayered core-shell structure can have a particle size from about 0.1 microns to about 100 microns, including all subranges in between. In other aspects, each multilayered core-shell structure can have a particle size from about 0.1 microns to about 10 microns, from about 1 micron to about 5 microns, from about 1 micron to about 100 microns, or from about 5 microns to about 50 microns.

[0055] In some aspects, the methods disclosed herein can include ball-milling the plurality of core structures, prior to performing a plurality of coating and thermal treating steps.

[0056] As noted above, additional coating and thermal treating steps can be carried on the foregoing multilayered core-shell structures, as described in more detail below.

[0057] In some aspects, the plurality of coating and thermal treating steps can further include coating at least a portion of the plurality of multilayered core-shell structures with a third sol-gel solution and thermal treating the at least partially coated plurality of multilayered core-shell structures, in which the third sol-gel solution includes vanadium oxide.

[0058] In further aspects, after coating at least a portion of the plurality of multilayered core-shell structures with the third sol-gel solution and thermal treating the at least partially coated plurality of multilayered core-shell structures, each multilayered core-shell structure of the plurality of multilayered core-shell structures can have an amount of silicon at an outer-most surface thereof, in which the amount of silicon at the outer-most surface is less than the amount of silicon at an outer surface of each multilayered core-shell structures that were coated with only the first and second sol-gel solutions and thermally treated. In such aspects, for each multilayered core-shell structure coated with the third sol-gel solution, the amount of silicon at the outer-most surface can be about 20 % or less of the total amount ofAtty. Docket No.: 037866-734001WO silicon present in the respective multilayered core-shell structure. In some aspects, the amount of silicon at the outer-most surface can be about 10 % or less or about 5 % or less of the total amount of silicon present in the respective multilayered core-shell structure

[0059] The third sol-gel solution includes vanadium oxide. In some aspects, vanadium oxide can include vanadium pentoxide (V2O5), vanadium dioxide (VO2), vanadium trioxide (V2O3), vanadium monoxide (VO), or any combination thereof. In one aspect, the vanadium oxide can include vanadium pentoxide (V2O5). In certain aspects, the third sol-gel solution and the first and / or second sol-gel solutions include the same components, whereas in other aspects, the third sol-gel solution and the first and / or second sol-gel solutions can include at least one different component. Further, the vanadium oxide present in the third sol-gel solution can vary. For example, in some aspects, the vanadium oxide can be present in the third sol-gel solution in a third amount from about 1 weight percent to about 90 weight percent, including all the subranges in between. In other aspects, the vanadium oxide can be present in the third sol-gel solution in a third amount from about 1 weight percent to about 30 weight percent or from about 1 weight percent to about 50 weight percent.

[0060] In some aspects, the vanadium oxide can be present in the third sol-gel solution in a third amount that is equal to or greater than the first amount of vanadium oxide present in the first sol-gel solution and / or, the second amount of vanadium oxide present in the second sol-gel solution. In other aspects, the vanadium oxide can be present in the third sol-gel solution in a third amount that is less than the first amount of vanadium oxide present in the first sol-gel solution and / or the second amount of vanadium oxide present in the second sol- gel solution.

[0061] In some aspects, each multilayered core-shell structure coated with the third sol- gel solution can have a particle size from about 0.1 microns to about 100 microns, including all subranges in between. In other aspects, each multilayered core-shell structure coated with the third sol-gel solution can have a particle size from about 0.1 microns to about 10 microns, from about 1 micron to about 5 microns, from about 1 micron to 100 microns, or from about 5 microns to about 50 microns.

[0062] In some aspects, the plurality of coating and thermal treating steps can further include coating, after coating at least a portion of the plurality of multilayered core-shell structures with the third sol-gel solution and thermal treating the partially coated multilayeredAtty. Docket No.: 037866-734001WO core-shell structures, at least a portion of the plurality of multilayered core-shell structures with a fourth sol-gel solution and thermal treating the at least partially coated plurality of multilayered core-shell structures, in which the fourth sol-gel solution includes vanadium oxide.

[0063] The fourth sol-gel solution includes vanadium oxide. In some aspects, vanadium oxide can include vanadium pentoxide (V2O5), vanadium dioxide (VO2), vanadium trioxide (V2O3), vanadium monoxide (VO), or any combination thereof. In one aspect, the vanadium oxide can include vanadium pentoxide (V2O5). In certain aspects, the fourth sol-gel solution and the first and / or second and / or third sol-gel solutions include the same components, whereas in other aspects, the fourth sol-gel solution and the first and / or second and / or third sol-gel solutions can include at least one different component. Further, the vanadium oxide present in the fourth sol-gel solution can vary. For example, in some aspects, the vanadium oxide can be present in the fourth sol-gel solution in a fourth amount from about 1 weight percent to about 90 weight percent, including all the subranges in between. In other aspects, the vanadium oxide can be present in the fourth sol-gel solution in a fourth amount from about 1 weight percent to about 30 weight percent or from about 1 weight percent to about 50 weight percent.

[0064] In some aspects, the vanadium oxide can be present in the fourth sol-gel solution in a fourth amount that is equal to or greater than the first amount of vanadium oxide present in the first sol-gel solution and / or the second amount of vanadium oxide present in the second sol-gel solution, and / or the third amount of vanadium oxide present in the third sol-gel solution. In other aspects, the vanadium oxide can be present in the fourth sol-gel solution in a fourth amount that is less than the first amount of vanadium oxide present in the first sol-gel solution and / or the second amount of vanadium oxide present in the second sol-gel solution, and / or the third amount of vanadium oxide present in the third sol-gel solution.

[0065] In further aspects, after coating at least a portion of the plurality of multilayered core-shell structures with the fourth sol-gel solution and thermal treating the at least partially coated plurality of multilayered core-shell structures, each multilayered core-shell structure of the plurality of multilayered core-shell structures can have an amount of silicon at an outer-most surface thereof, in which the amount of silicon at the outer-most surface is less than the amount of silicon at an outer surface of each multilayered core-shell structures that were coated with only the first, second, and third sol-gel solutions and thermally treated. InAtty. Docket No.: 037866-734001WO such aspects, for each multilayered core-shell structure coated with the fourth sol-gel solution, the amount of silicon at the outer-most surface can be about 5 % or less of the total amount of silicon present in the respective multilayered core-shell structure. In such aspects, for each multilayered core-shell structure coated with the fourth sol-gel solution, the amount of silicon at the outer-most surface can be about 3 % or less or about 1 % or less of the total amount of silicon present in the respective multilayered core-shell structure.

[0066] In some aspects, each multilayered core-shell structure coated with the fourth sol- gel solution can have a particle size from about 0.1 microns to about 100 microns, including all subranges in between. In other aspects, each multilayered core-shell structure coated with the fourth sol-gel solution can have a particle size from about 0.1 microns to about 10 microns, from about 1 micron to about 5 microns, from about 1 micron to 100 microns, or from about 5 microns to about 50 microns.

[0067] In some aspects, the plurality of coating and thermal treating steps can further include coating, after coating at least a portion of the plurality of multilayered core-shell structures with the fourth sol-gel solution, at least a portion of the plurality of multilayered core-shell structures with a fifth sol-gel solution and thermal treating the at least partially coated plurality of multilayered core-shell structures, in which the fifth sol-gel solution includes vanadium oxide.

[0068] The fifth sol gel solution includes vanadium oxide. In some aspects, vanadium oxide can include vanadium pentoxide (V2O5), vanadium dioxide (VO2), vanadium trioxide (V2O3), vanadium monoxide (VO), or any combination thereof. In one aspect, the vanadium oxide can include vanadium pentoxide (V2O5). In certain aspects, the fifth sol-gel solution and the first and / or second and / or third and / or fourth sol-gel solutions include the same components, whereas in other aspects, the fifth sol-gel solution and the first and / or second and / or third and / or fourth sol-gel solutions can include at least one different component. Further, the vanadium oxide present in the fifth sol-gel solution can vary. For example, in some aspects, the vanadium oxide can be present in the fifth sol-gel solution in a fifth amount from about 1 weight percent to about 90 weight percent, including all the subranges in between. In other aspects, the vanadium oxide can be present in the fifth sol-gel solution in a fifth amount from about 1 weight percent to about 30 weight percent or from about 1 weight percent to about 50 weight percent.Atty. Docket No.: 037866-734001WO

[0069] In some aspects, the vanadium oxide can be present in the fifth sol-gel solution in a fifth amount that is equal to or greater than the first amount of vanadium oxide present in the first sol-gel solution and / or the second amount of vanadium oxide present in the second sol-gel solution, and / or the third amount of vanadium oxide present in the third sol-gel solution, and / or the fourth amount of vanadium oxide present in the fourth sol-gel solution. In other aspects, the vanadium oxide can be present in the fifth sol-gel solution in a fifth amount that is less than the first amount of vanadium oxide present in the first sol-gel solution and / or the second amount of vanadium oxide present in the second sol-gel solution, and / or the third amount of vanadium oxide present in the third sol-gel solution, and / or the fourth amount of vanadium oxide present in the fourth sol-gel solution.

[0070] In further aspects, after coating at least a portion of the plurality of multilayered core-shell structures with the fifth sol-gel solution and thermal treating the at least partially coated plurality of multilayered core-shell structures, each multilayered core-shell structure of the plurality of multilayered core-shell structures can have an amount of silicon at an outer-most surface thereof, in which the amount of silicon at the outer-most surface is less than the amount of silicon at an outer surface of each multilayered core-shell structures that were coated with only the first, second, third, and fourth sol-gel solutions and thermally treated. In such aspects, for each multilayered core-shell structure coated with the fifth sol- gel solution, the amount of silicon at the outer-most surface can be about 1 % or less of the total amount of silicon present in the respective multilayered core-shell structure. In certain aspects, the amount of silicon at the outer-most surface can be about 0.1 % or less of the total amount of silicon present in the respective multilayered core-shell structure.

[0071] In some aspects, each multilayered core-shell structure coated with the fifth sol- gel solution can have a particle size from about 0.1 microns to about 100 microns, including all subranges in between. In other aspects, each multilayered core-shell structure coated with the fifth sol-gel solution can have a particle size from about 0.1 microns to about 10 microns, from about 1 micron to about 5 microns, from about 1 micron to 100 microns, or from about 5 microns to about 50 microns.

[0072] In some aspects, each multilayered core-shell structure coated with the fifth sol- gel solution can have a volumetric porosity from about 20 % to about 80 %. In certain aspects, each multilayered core-shell structure coated with the fifth sol-gel solution can have a volumetric porosity from about 40 % to about 80 %.Atty. Docket No.: 037866-734001WO

[0073] In some aspects, the first sol-gel solution, second sol-gel solution, the third sol-gel solution, the fourth sol-gel solution, the fifth sol-gel solution, or any combination thereof can include one or more dopants. The one or more dopants can include B, Mg, Ca, Al, Ti, Nb, Ta, K, Na, Zn, Fe, Cu, Sc, Y, La, Si, Ge, Sn, Zr, Mn, P, Nb, Cr, Mo, W, Se, or any combination thereof.

[0074] In further aspects, the plurality of coating and thermal treating steps can include coating, after coating at least a portion of the plurality of multilayered core-shell structures with the fifth sol-gel solution, at least a portion of the plurality of multilayered core-shell structures with one or more additional sol-gel solutions and, after each coating, thermal treating, the at least partially coated plurality of multilayered core-shell structures, the one or more additional sol-gel solutions include vanadium oxide.

[0075] In some aspects, thermal treating the partially coated silicon-carbon mixture can include drying the partially coated silicon-carbon mixture at a first temperature from about 60 °C to about 200 °C, followed by drying at a second temperature from about 250 °C to about 500 °C. Alternatively, or in addition, thermal treating the at least partially coated plurality of core-shell structures can include drying the at least partially coated plurality of core-shell structures at a first temperature from about 60 °C to about 200 °C, followed by drying at a second temperature from about 250 °C to about 500 °C. Alternatively, or in addition, thermal treating the at least partially coated plurality of multilayered core-shell structures can include drying the at least partially coated plurality of multilayered core-shell structures at a first temperature from about 60 °C to about 200 °C, followed by drying at a second temperature from about 250 °C to about 500 °C. In certain aspects, the first temperature can be from about 60 °C to about 120 °C or from about 100 °C to about 120 °C, including all subranges in between, whereas the second temperature can be from about 250 °C to about 400 °C or about 300 °C to about 400 °C, including all subranges in between.

[0076] FIG.1A illustrates an exemplary schematic of a multilayered core-shell structure 100 that includes two coating layers 102 and 104 of vanadium oxide, and FIG.1B illustrates an exemplary process of performing a plurality of coating and thermal treating steps that form the multilayered core-shell structure 100. In this illustrated aspect, a core structure 107 is provided, in which the core structure 107 includes silicon particles 108 and one or more carbon materials 110 (e.g., carbon nanotubes). The core structure 107 is then partially coated with a first sol-gel material and thermally treated to thereby form a core-shell structure 112.Atty. Docket No.: 037866-734001WO In other words, the core-shell structure 112 is formed of the core structure 107 and the first coating 102. The core-shell structure 112 is then coated with a second sol-gel solution and thermally treated to thereby from the multilayered core-shell structure 100. As such, the multilayered core-shell structure 100 is formed of the core-shell structure 112 and the second coating. While the multilayered core-shell structure 100 is illustrated with two coating layers 102 and 104, in other aspects, the multilayered core-shell structure 100 can include additional coatings layers (e.g., 3, 4, 5, 6, etc.), which can be applied similarly to that of the second coating layer 104.

[0077] In some aspects, the core structures can be created by ball milling and mixing the one or more carbon materials with the at least one silicon particle. In other aspects, a core structure can be formed by using as a carbon additive to form a 3D porous carbon host for the silicon, and. the resulting core structure can then be converted into a multilayered core-shell structure (e,g., a SVO structure) by employing iterative coating and thermal treating steps (e.g., for ach coating step using a sol-gel solution) to form the multilayered core-shell structures disclosed herein, e.g., as illustrated in FIG.2. As shown in FIG.2, the process 200 illustrates silicon particles 202 uniformly dispersed with carbon nanotubes 204 in carboxymethyl cellulose (CMC) 206. This mixture is then dried causing the CMC to gelatinize to form a core structure 208. The core structure 208 is then carbonized under Ar, thereby forming a 3D porous carbon host for silicon. This 3D porous carbon host for silicon includes, in addition to the silicon particles 202 and carbon nanotubes 204, pyrolyzed carbon 210 and pores 212 defined therein. The core structure 208 can then be iteratively coated and thermally treated (e.g., for each coating step using a sol-gel solution) to form a multilayered core-shell structure 214.

[0078] In some aspects, single silicon particles can each be coated with one or more carbon materials, and the resulting particles can then be individually coated with a first sol- material and thermally treated to form a respective core-shell structure. For example, as shown in FIG.3A, a single silicon particle 302 is coated with carbon nanotubes 304, which in combination is a core structure, and then further coated with a first coating 306 to thereby form a core-shell structure 308. The first coating 306 can be formed by coating a sol-gel solution on the carbon-coated silicon particle and thereafter thermally treated. A plurality of these core structures can then aggregate together during a subsequent coating and thermallyAtty. Docket No.: 037866-734001WO treating step, thereby forming a multilayered core-shell structure 310 with a second coating 312, as illustrated in FIG.3B.

[0079] In certain aspects, a process that can be used to form a multilayered core-shell structure with a similar configuration as that of multilayered core-shell structure 310 of FIG. 3B can include dispersing single silicon particles in a V2O5 / CNT solution and then coated with V2O5 and CNT. During the sol-gel process, the silicon particles become wrapped in CNT and V2O5ribbons. The iterative sol-gel process involves repeatedly adding V5+ solution to facilitate the formation of the coating layer. As the coating develops and the V5+ concentration decreases, more V5+ solution is added to continue the sol-gel cycle. Repeating this step results in secondary particles, with each primary silicon particle individually coated with V2O5 / CNT.

[0080] In some aspects, during one or more coating and thermal treating steps of the multilayered core-shell structures, at least a portion of these structures can aggregate together. In such instances, after aggregation, any further coating and thermal treating steps can form one or more multilayered core-shell structures that each include a plurality of multilayered core-shell structures. For example, in one aspect, while two or more multilayered core-shell structures, such as two or more of the multilayer core-shell structure 100 of FIG.1B, are being formed at least a portion of these structures can aggregate together. As such, when the aggregated shell structures are later coated with a third sol-gel solution and thermally treated, one or more multilayered core-shells structures can be formed that each include an aggregation of multilayered core-shells structures coated with a third coating, as shown in FIG.4. FIG.4 is a schematic illustration of a multilayered core-shell structure 400 formed of an aggregation of two multilayered core-shell structures 100 of FIG.1A that are together coated with a third coating 402. Similarly, FIG.5 is a schematic illustration of a multilayered core-shell structure 500 formed of an aggregation of three multilayered core-shell structures 410 of FIG.4B that are together coated with a third coating 502.

[0081] FIG.6 is a schematic showing a Si-CNT core structure 602, a core-shell structure 604, a first multilayered core-shell structure 606, and a second multilayered core-shell structure 608. The first multilayered core-shell structure 606 underwent two iterative (i.e., repetitive) coating and thermal treating processes, and the second multilayered core-shell structure 608 underwent three iterative coating and thermal treating processes. More specifically, once the core structure 602 is formed, it is then coated with a first sol-gelAtty. Docket No.: 037866-734001WO solution and then dried to form the core-shell structure 604, which includes one coating layer. The core-shell structure 604 is then coated with a second sol-gel solution and then dried to form the first multilayered core-shell structure 606, which includes two coating layers. Lastly, the first multilayered core-shell structure 606 is then coated with a third sol-gel solution and then dried to form the second multilayered core-shell structure 608, which includes three coating layers. While only three coating / drying processes are illustrated, it is also contemplated herein that the overall method of making an anode material can include only 2 coating / drying processes or more than 3 coating / drying processes to effect an anode material as disclosed herein. As such, for each anode material disclosed herein, it includes at least one multilayered core-shell structure.

[0082] In further aspects, the methods disclosed herein can include lithiating, after completing the plurality of coating and thermal treating steps, crystallized vanadium oxide of the plurality of multilayered core-shell structures, thereby generating the anode material, wherein each layer of a multilayered core-shell structure of the plurality of multilayered core- shell structures includes lithium vanadium oxide material. In such aspects, lithiating crystallized vanadium oxide of the plurality of multilayered core-shell structures can include lithiating the crystallized vanadium oxide of the plurality of multilayered core-shell structures with a lithium-containing reducing agent. In certain aspects, during the lithiation step, the silicon can also be lithiated, thereby forming LixSi, where x is greater than 0 and less than or equal to 3.75.

[0083] In some aspects, the lithium-containing reducing agent can include butyl lithium (LiC4H9), lithium naphthalene (LiC10H8), lithium anthracenide (LiC14H9), or any combinations thereof.

[0084] In some aspects, the lithium vanadium oxide material can have a formula LiaVbOc, wherein a = 0–10, b = 1–3, c = 1–9, and a, b, and c are selected to charge-balance the LiaVbOc. In some aspects, the LiaVbOccan include Li3V2O5, Li4V2O5, Li5V2O5, LiVO2, LiV2O5, Li2V2O5, LiVO3, LiV3O8, Li2V3O8, Li3V3O8, LiV2O3, Li2V2O3, Li3V2O3, or any combinations thereof. The LiaVbOccan be crystalline. The LiaVbOccan have a density of about 2.0 g / cm3to about 4.5 g / cm3.

[0085] In some aspects, at least 50 wt%, 60 wt%, 70 wt%, 80 wt%, 90 wt%, 95 wt%, or 99 wt% (such as 100 wt%) of the LiaVbOc can have a disordered rocksalt structure in theAtty. Docket No.: 037866-734001WO Fm3m space group.. In certain aspects, at least 50 wt% of the LiaVbOccan have a disordered rocksalt structure in the Fm3m space group.In one aspect, at least 90 wt% of the LiaVbOc can have a disordered rocksalt structure in the Fm3m space group.

[0086] In some aspects, the LiaVbOc can be present in a pre-lithiated state, wherein a = 0 in the LiaVbOc. Alternatively, such as prior to or during use of the anode material, the LiaVbOc can be present in a lithiated state, wherein a > 0 in the LiaVbOc.

[0087] In some aspects, the lithium vanadium oxide material can be doped with one or more dopants M, in which the doped lithium vanadium oxide material can have a formula LiaVbOcMd, in which d = 0.1–3, a, b, c, and d are selected to charge-balance the LiaVbOcMd and optionally wherein LiaVbOcMd is capable of being reversibly lithiated. In such instances, one or more dopants M can include B, Mg, Ca, Al, Ti, Nb, Ta, K, Na, Zn, Fe, Cu, Sc, Y, La, Si, Ge, Sn, Zr, Mn, P, Nb, Cr, Mo, W, Se, or any combination thereof. In some aspects, at least 50 wt% or at least 90 wt% of the LiaVbOcMdcan have a disordered rocksalt structure in the Fm3m space group.

[0088] The anode materials disclosed herein can be implemented into an anode. By way of example, in some aspects, an exemplary manufacturing process of an anode can include synthesizing a plurality of core structures (e.g., CNT-Si core structures), forming a plurality of core-shell structures (e.g., V2O5-Si-CNT core-shell structures), coating core-shell structures with a sol-gel solution (e.g., a V2O5layer) and thermally treating them to form a plurality of multilayered core-shell structures (e.g., SVO), and thereafter mixing the multilayered core-shell structures with carbon additives and binders to form a slurry and casing the slurry on a negative current collector (e.g., copper substrate). In some aspects, the process can include carrying out one or more coating and thermally treating steps (e.g., iterative steps) on the multilayered core-shells structures. Alternatively, or in addition, the process can further include electrochemically or chemically lithiating the multilayered core- shell structures to produce, e.g., Si-CNT-Li3V2O5(SLVO).

[0089] The anode can further contain graphite, non-graphitized carbon, silicon oxides, tin, tin oxides, or a combination thereof. The anode can further contain one or more binders. Non-limiting examples of suitable one or more binders includes carboxymethyl cellulose, styrene-butadiene rubber, styrene-butadiene copolymer, polyvinylidene fluoride, andAtty. Docket No.: 037866-734001WO combinations thereof, or other homopolymers or copolymers, for example. The one or more binders can present in a concentration from about 0.1 wt% to about 50 wt% in the anode.

[0090] The anode may have an average anode thickness from about 200 nanometers to about 200 microns, for example. The anode, along with a cathode, can be present in a cell (e.g., battery cell). The cathode can include a cathode material. Non-limiting examples of suitable cathode materials include LiFePO4, LiMn2O4, LiNi0.5Mn1.5O4, LiNixCoyMnzO2wherein x + y + z = 1, LiCoO2, LiNixCoyAlzO2 wherein x + y + z = 1, LiFexMnyPO4 wherein x + y = 1, aLiNixCoyMnzO2·(1–a)Li2MnO3 wherein a = 0–1 and x + y + z = 1, and combinations thereof, for example.

[0091] In general, a method of making a battery cell includes casting a slurry on a negative current collector to form an anode on the negative current collector, in which the slurry includes any anode material disclosed herein, stacking a separator on the anode, in which the separator includes an electrolyte, casting a cathode material on a positive current collector to form a cathode on the positive current collector, and stacking the cathode on the separator. Further, a method of making a battery includes providing one or more battery cells disclosed herein.

[0092] An exemplary battery cell 800 is shown in FIG.8, in which the battery cell 800 includes an anode 802 on a surface of a negative current collector 804 (e.g., copper substrate), where the anode 802 is formed of any anode material disclosed herein, a separator 806 on or proximate to a surface of the anode 802, in which the separator includes an electrolyte (not shown), a cathode 808 on or proximate to a surface of the separator 806, and a positive current collector 810 on or proximate a surface of the cathode 808.

[0093] The method can further include introducing, to the anode material, one or more additives. Non-limiting examples of suitable additives includes graphite, non-graphitized carbon, silicon oxides, tin, tin oxides, or any combination thereof, for example.

[0094] The method can further include introducing, to the anode material, one or more binders. Non-limiting examples of suitable binders include carboxymethyl cellulose, styrene- butadiene rubber, styrene-butadiene copolymer, polyvinylidene fluoride, and any combination thereof, for example.Atty. Docket No.: 037866-734001WO

[0095] In some aspects, the electrolyte can include a liquid electrolyte, a polymer gel electrolyte, or a combination thereof. In certain aspects, the lithium vanadium oxide material can be impermeable to the electrolyte.

[0096] In the cell formed, the anode may have an anode-material loading selected from about 0.2 mg / cm2to about 50 mg / cm2. The anode may have an areal capacity on at least one side of the anode selected from about 0.05 mA ·h / cm2to about 10 mA ·h / cm2. In certain aspects, the anode can have an areal capacity on both sides of the anode selected from about 0.05 mA ·h / cm2to about 10 mA·h / cm2. The anode thickness can be from about 200 nanometers to about 200 microns, for example.

[0097] When the cell undergoes at least one charge–discharge cycle, the lithium vanadium oxide material can have a volume change from 0% to about 20% during the charge–discharge cycle(s).

[0098] In general, the cell can be repeatedly charged and discharged over multiple charge–discharge cycles, wherein the LiaVbOc is reversibly lithiated and delithiated a plurality of times. The cell can be charged and discharged over at least 1000 cycles, for example.

[0099] The anode can have an areal capacity on at least one side of the anode from about 0.05 mA ·h / cm2to about 10 mA ·h / cm2. In certain aspects, the anode has an areal capacity on both sides of the anode from about 0.05 mA ·h / cm2to about 10 mA ·h / cm2. In various aspects, the anode can have an areal capacity on both sides of the anode of about, or at least about 0.05, 0.1, 0.2, 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 8, 9, or 10 mA h / cm2, including any intervening ranges.

[0100] In general, the cell can be repeatedly charged and discharged over multiple charge–discharge cycles, wherein the LiaVbOc is reversibly lithiated and delithiated a plurality of times. The cell may be charged and discharged over at least 1000 cycles, for example. In various aspects, the number of charge–discharge cycles is 1, 2, 3, 4, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1500, 2000, 2500, 3000, 3500, 4000, 4500, or 5000, or even more, for example.

[0101] When the cell undergoes at least one charge–discharge cycle, the lithium vanadium oxide material can have a volume change from 0% to about 20% during theAtty. Docket No.: 037866-734001WO charge–discharge cycle(s). In various aspects, after one charge–discharge cycle, the lithium vanadium oxide material can have a volume change of about, or at most about 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5.5%, 5%, 4.5%, 4%, 3.5%, 3%, 2.5%, 2%, 1.5%, 1%, 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, 0.1%, or 0.0%, including any intervening ranges. In certain aspects, after 2, 3, 4, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, or 1000 charge–discharge cycles, the lithium vanadium oxide material can have a volume change of about, or at most about 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5.5%, 5%, 4.5%, 4%, 3.5%, 3%, 2.5%, 2%, 1.5%, 1%, 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, 0.1%, or 0.0%, including any intervening ranges.

[0102] The following specific examples are intended to be illustrative of the subject matter and should not be construed as limiting the scope of the subject matter as defined by appended claims. EXAMPLES

[0103] The following specific examples are intended to be illustrative of the subject matter and should not be construed as limiting the scope of the subject matter as defined by appended claims.

[0104] Example 1: CNT-Si-Core Solution Synthesis

[0105] 0.2003g of Si nanoparticles (~100 nm, US NANO) were mixed with 0.4669g of ethanol. Thinky for 1 minute at 2000 rpm. 1 ml CNT-solution (Sigma, single-walled, conductive aqueous ink, 0.9-1.1 g / L) was then added into the Si dispersion, the mixture was firstly dried in a convection oven at 70 °C to remove the ethanol, and the dried mixture was then ball milled for 12 h @ 500 rpm using a planetary ball-mill machine by Tmax to produce CNT / Si core structures. FIG.7A is a SEM image of one of the CNT / Si core structures. These CNT / SI core structures were then re-dispersed into 1ml ethanol solvent in a 20 ml glass bottle to produce the CNT-Si-Core solution.Atty. Docket No.: 037866-734001WO

[0106] Example 2: First V205 Sol-Gel Solution Synthesis—V2O5

[0107] 0.5mL of H2O2 and 1mL of DI water were added into a small glass vile. The mixture was stirred on low speed on a heating plate with no heat on. Then 0.05g of V2O5 was added into the vile and stirred for ~5 minutes to form a first V2O5 sol-gel solution.

[0108] Example 3: Core-Shell Structure Synthesis—V2O5-Si-CNT

[0109] 15.0226g of ethanol was added into a beaker and stirred at 600 rpm with no heat on. The CNT-Si-Core solution made in Example 1 was added into the mixing beaker using a disposable dropper.4.9854g of ethanol was then used to wash the CNT-Si-Core solution bottle and transfer any remaining CNT-Si-Core solution into the beaker. The heat was then turned on to 100 °C, and the stirring speed was lowered to 300 rpm. The mixture was heated for about 2.5 hours until most of the ethanol was evaporated. Then the mixture was dried under 120 °C for 360 minutes in a vacuum oven. The mixture was then baked under 350 °C for 60 minutes under 1 atm to form core-shell structures, which were then ground using a mortar and pestle to break down aggregations. FIG.7B is a SEM image of one of the core- shell structures.

[0110] Example 4: Multilayered Core-Shell Structure Synthesis—V2O5-Si-CNT (First Iteration)

[0111] Second V2O5 sol-gel solution synthesis: 2mL of H2O2 and 1mL of DI water were added into a small glass vile. The mixture was stirred on low speed on a heating plate with no heat on. Then 0.2035g of V2O5 was added into the vile and stirred for ~5 minutes to form a second V2O5 sol-gel solution.

[0112] Multilayered Core-Shell Structure Synthesis (2 coating layers): 15.0226g of ethanol was added into a beaker and stirred at 600 rpm with no heat on. The ground core- shell structures made in Example 3 were then transferred into the beaker while stirring to uniformly disperse the core-shell structures in the ethanol. Before transferring the second V2O5 sol-gel solution into the beaker, another 0.5mL of H2O2 was added into the vile and stir until the sol-gel solution was transparent. The second V205 sol-gel solution was then transferred (drop by drop) into the beaker. The heat was then turned on to 100 °C, and the stirring speed was lowered to 400 rpm. The mixture was heated for about 2.5 hours until most of the ethanol was evaporated. Then the mixture was dried under 120 °C for 360Atty. Docket No.: 037866-734001WO minutes in a vacuum oven. The mixture was then baked under 350 °C for 60 minutes under 1 atm to form multilayered core-shell structures having 2 coating layers, which were then ground using a mortar and pestle to break down aggregations. FIG.7C is a SEM image of one of the multilayered core-shell structures.

[0113] Example 5: Multilayered Core-Shell Structure Synthesis—V2O5-Si-CNT (Second Iteration)

[0114] Third V2O5 sol-gel solution synthesis: 0.5 mL of H2O2 and 1mL of DI water were added into a small glass vile. The mixture was stirred on low speed on a heating plate with no heat on. Then 0.05012g of V2O5 was added into the vile and stirred for ~5 minutes to form a third V2O5 sol-gel solution.

[0115] Multilayered Core-Shell Structure Synthesis (3 coating layers): 15.0226g of ethanol was added into a beaker and stirred at 600 rpm with no heat on. The ground multilayered core-shell structures made in Example 4 were transferred into the beaker while stirring to uniformly disperse the multilayered core-shell structures in the ethanol. Before transferring the third V2O5 sol-gel solution into the beaker, another 0.5mL of H2O2 was added into the vile and stir until the sol-gel solution was transparent. The third V2O5 sol-gel solution was then transferred (drop by drop) into the beaker. The heat was then turned on to 100 °C, and the stirring speed was lowered to 300 rpm. The mixture was heated for about 2.5 hours until most of the ethanol was evaporated. Then the mixture was dried under 120 °C for 360 minutes in a vacuum oven. The mixture was then baked under 350 °C for 60 minutes under 1 atm to form multilayered core-shell structures having 3 coating layers.

[0116] Example 6: Multilayered Core-Shell Structure Synthesis—V2O5-Si-CNT (Third Iteration)

[0117] Fourth V2O5 sol-gel solution synthesis: 0.5 mL of H2O2 and 1mL of DI water were added into a small glass vile. The mixture was stirred on low speed on a heating plate with no heat on. Then 0.05012g of V2O5 was added into the vile and stirred for ~5 minutes to form a fourth V2O5 sol-gel solution.

[0118] Multilayered Core-Shell Structure Synthesis (4 coating layers): 15.0226g of ethanol was added into a beaker and stirred at 600 rpm with no heat on. The multilayered structures made in Example 5 were transferred into the beaker while stirring to uniformlyAtty. Docket No.: 037866-734001WO disperse the multilayered core-shell structures in the ethanol. Before transferring the fourth V2O5 sol-gel solution into the beaker, another 0.5mL of H2O2 was added into the vile and stir until the sol-gel solution was transparent. The fourth V2O5 sol-gel solution was then transferred (drop by drop) into the beaker. The heat was then turned on to 100 °C, and the stirring speed was lowered to 300 rpm. The mixture was heated for about 2.5 hours until most of the ethanol was evaporated. Then the mixture was dried under 120 °C for 360 minutes in a vacuum oven. The mixture was then baked under 350 °C for 60 minutes under 1 atm to form multilayered core-shell structures having 4 coating layers, which were then ground using a mortar and pestle to break down aggregations.

[0119] Example 7: Multilayered Core-Shell Structure Synthesis—V2O5-Si-CNT (Fourth Iteration)

[0120] Fifth V2O5 sol-gel solution synthesis: 0.5 mL of H2O2 and 1mL of DI water were added into a small glass vile. The mixture was stirred on low speed on a heating plate with no heat on. Then 0.05012g of V2O5 was added into the vile and stirred for ~5 minutes to form a fifth V2O5 sol-gel solution.

[0121] Multilayered Core-Shell Structure Synthesis (5 coating layers): 15.0226g of ethanol was added into a beaker and stirred at 600 rpm with no heat on. The ground multilayered core-shell structures made in in Example 6 were transferred into the beaker stirring to uniformly disperse the multilayered core-shell structures in the ethanol. Before transferring the fifth V2O5 sol-gel solution into the beaker, another 0.5mL of H2O2 was added into the vile and stir until the sol-gel solution was transparent. The fifth V2O5 sol-gel solution was then transferred (drop by drop) into the beaker. The heat was then turned on to 100 °C, and the stirring speed was lowered to 300 rpm. The mixture was heated for about 2.5 hours until most of the ethanol was evaporated. Then the mixture was dried under 120 °C for 360 minutes in a vacuum oven. The mixture was then baked under 350 °C for 60 minutes under 1 atm to form multilayered core-shell structures having 5 coating layers, which were then ground using a mortar and pestle to break down aggregations. FIG.7D is a SEM image of one of the multilayered core-shell structures.

[0122] Example 8: Multilayered Core-Shell Structure Cell Testing—SVO (nthiteration)Atty. Docket No.: 037866-734001WO

[0123] Anode Synthesis: 2g NMP (N-Methyl-2-pyrrolidone, NMP, sigma), 0.3g SVO(nthiteration) with 0.15g Carbon additive (carbon black, Sigma) and 0.1g binder (Arkema Kynar HSV 1800 Polyvinylidene Difluoride PVDF) using a Thinky mixer to make a slurry. Casting slurry to make the electrode with a loading of 2 mg / cm^2.

[0124] Cell assembly: 2016 cell case with a lithium counter electrode (diameter = 16 mm, thickness = 250 um) was used for half-cell testing.

[0125] Cell testing: Assembled 2016 cells were tested using the Neware Cell testing system. All cells were cycled between 0.01V to 2V under a constant current density 1 A / g.

[0126] As shown in FIG.9, the battery performance is illustrated using the as-synthesized SLVO. Four batteries were assembled using 2016 coin cell case, Li metal plate, and an anode. Each battery had a half-cell configuration. ^ First Battery (baseline battery): Anode was a pure Si-CNT composite. ^ Second Battery: Anode with 0.3g SVO, where the SVO was the core-shell structures formed in Example 3. ^ Third Battery: Anode with 0.3g SVO, where the SVO was the multilayered core-shell structures formed in Example 5. ^ Fourth Battery: Anode with 0.3g SVO, where the SVO was the multilayered core- shell structures formed in Example 7.

[0127] The batteries were run at 5C discharge / charge with 1000 mAh / g capacity cutoff for fair comparison. As shown in FIG.9, the electrode made with pure Si-CNT composite failed after only 10 cycles, consistent with previous reported data. However, compared to the pure Si-CNT composite, the third battery lasted more than 150 cycles and the fourth battery even lasted longer than 400 cycles.

[0128] The foregoing examples illustrate an exemplary iterative sol-gel coating method, consistent with the implementations of the current subject matter, that can be capable of synthesizing an anode material in a batch size of for example 100g (lab scale) or more and with a high reversible capacity of greater than (>) 1000 mAh / g that can be charged / discharged in just 5 minutes. This anode material can also be capable of 1000 cycles with less than 10% capacity loss and can remain stable after storage at 55 °C for one month with less than 10% capacity loss. By incorporating LVO protection, the silicon can beAtty. Docket No.: 037866-734001WO processed into a negative electrode. The LVO protected Si can be prelithiated to compensate for the Li inventory. This negative electrode can be paired with a 4V cathode such as Li-rich oxides and LiNi0.8Co0.1Mn0.1O2. The electrodes can be either alternatively stacked to make a pouch type cell or rolled up to make a cylinder cell. The cell can deliver a high energy density of 350 Wh / kg or higher. Additionally, this anode material can exhibit an extended calendar life, capable of storage at 55 °C or higher temperature for extended periods—1 month, 3 months, 1 year, or even 2 years—while fully lithiated, with no significant efficiency drop observed during subsequent usage.

[0129] Although various illustrative implementations are described above, any of a number of changes can be made to various implementations without departing from the teachings herein. For example, the order in which various described method steps are performed can often be changed in alternative implementations, and in other alternative implementations, one or more method steps can be skipped altogether. Optional features of various system and process implementations can be included in some implementations and not in others. Therefore, the foregoing description is provided primarily for exemplary purposes and should not be interpreted to limit the scope of the claims.

[0130] The examples and illustrations included herein show, by way of illustration and not of limitation, specific implementations in which the subject matter can be practiced. As mentioned, other implementations can be utilized and derived there from, such that structural and logical substitutions and changes can be made without departing from the scope of this disclosure. Such implementations of the inventive subject matter can be referred to herein individually or collectively by the term “invention” merely for convenience and without intending to voluntarily limit the scope of this application to any single invention or inventive concept, if more than one is, in fact, disclosed. Thus, although specific implementations have been illustrated and described herein, any arrangement calculated to achieve the same purpose can be substituted for the specific implementations shown. This disclosure is intended to cover any and all adaptations or variations of various implementations. Combinations of the above implementations, and other implementations not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description. Use of the term “based on,” herein and in the claims is intended to mean, “based at least in part on,” such that an unrecited feature or element is also permissible.Atty. Docket No.: 037866-734001WO

[0131] The subject matter described herein can be embodied in systems, apparatus, methods, and / or articles depending on the desired configuration. The implementations set forth in the foregoing description do not represent all implementations consistent with the subject matter described herein. Instead, they are merely some examples consistent with implementations related to the described subject matter. Although a few variations have been described in detail herein, other modifications or additions are possible. In particular, further features and / or variations can be provided in addition to those set forth herein. For example, the implementations described herein can be directed to various combinations and subcombinations of the disclosed features and / or combinations and subcombinations of several further features disclosed herein. In addition, the logic flows depicted in the accompanying figures and / or described herein do not necessarily require the particular order shown, or sequential order, to achieve desirable results. Other implementations can be within the scope of the following claims.

Claims

Atty. Docket No.: 037866-734001WO What is claimed is:

1. A method of manufacturing an anode material, the method comprising: providing a plurality of core structures, each core structure comprising at least one silicon particle; and performing a plurality of coating and thermal treating steps, wherein the plurality of coating and thermal treating steps comprises, coating at least a portion of the plurality of core structures with a first sol-gel solution and thermal treating the at least partially coated core structures to produce a plurality of core-shell structures, the first sol-gel solution comprising vanadium oxide, and coating at least a portion of the plurality of core-shell structures with a second sol-gel solution and thermal treating the at least partially coated plurality of core-shell structures to produce a plurality of multilayered core-shell structures, the second sol-gel solution comprising vanadium oxide.

2. The method of claim 1, wherein at least one core structure of the plurality of core structures comprises one silicon particle.

3. The method of claim 1, wherein at least one core structure of the plurality of core structures comprises a mixture of the at least one silicon particle and one or more carbon materials.

4. The method of any one of the preceding claims, wherein providing the plurality of core structures comprises mixing at least one silicon particle and one or more carbon materials together, wherein each core structure comprises at least one silicon particle and the one or more carbon materials.

5. The method of any one of claims 1 to 4, wherein providing the plurality of core structures comprises coating at least one silicon particle with one or more carbon materials, wherein each core structure comprises at least one silicon particle and the one or more carbon materials.

6. The method of any one of the preceding claims, wherein each core structure of the plurality of core structures has a particle size from about 0.1 microns to about 100 microns.Atty. Docket No.: 037866-734001WO 7. The method of any one of the preceding claims, wherein each core-shell structure of the plurality of core-shell structures has a particle size from about 0.1 microns to 100 microns.

8. The method of any one of the preceding claims, wherein each core-shell structure of the plurality of core-shell structures has an amount of silicon at an outer-most surface thereof, wherein the amount of silicon at the outer-most surface is less than the amount of silicon particles at an outer surface of each core structure of the plurality of core structures.

9. The method of claim 8, wherein the amount of silicon at the outer-most surface of each core-shell structure is about 40 % or less of the total amount of silicon present in the respective core-shell structure.

10. The method of any one of the preceding claims, wherein each multilayered core-shell structure of the plurality of multilayered core-shell structures has a particle size from about 0.1 microns to about 100 microns.

11. The method of any one of the preceding claims, wherein each multilayered core-shell structure of the plurality of multilayered core-shell structures has an amount of silicon at an outer-most surface thereof, wherein the amount of silicon at the outer-most surface is less than the amount of silicon at an outer surface of each core-shell structure of the plurality of core-shell structures.

12. The method of claim 11, wherein, for each multilayered core-shell structure, the amount of silicon at the outer-most surface is about 40% or less of the total amount of silicon present in the respective multilayered core-shell structure.

13. The method of any one of the preceding claims, wherein the vanadium oxide is present in the first sol-gel solution in a first amount from about 1 weight percent to about 90 weight percent.

14. The method of any one of the preceding claims, wherein the vanadium oxide is present in the second sol-gel solution in a second amount from about 1 weight percent to about 90 weight percent.Atty. Docket No.: 037866-734001WO 15. The method of any one of the preceding claims, wherein the vanadium oxide is present in the first sol-gel solution in a first amount and the vanadium oxide is present in the second sol-gel solution in a second amount that is equal to or greater than the first amount.

16. The method of any one of claims 1 to 14, wherein the vanadium oxide is present in the first sol-gel solution in a first amount and the vanadium oxide is present in the second sol- gel solution in a second amount that is less than the first amount.

17. The method of any one of the preceding claims, wherein the plurality of coating and thermal treating steps further comprises, coating at least a portion of the plurality of multilayered core-shell structures with a third sol-gel solution and thermal treating the at least partially coated plurality of multilayered core-shell structures, the third sol-gel solution comprising vanadium oxide.

18. The method of claim 17, wherein, after coating at least a portion of the plurality of multilayered core-shell structures with the third sol-gel solution and thermal treating the at least partially coated plurality of multilayered core-shell structures, each multilayered core- shell structure of the plurality of multilayered core-shell structures has a particle size from about 0.1 microns to about 100 microns.

19. The method of claim 17 or claim 18, wherein after coating at least a portion of the plurality of multilayered core-shell structures with the third sol-gel solution and thermal treating the at least partially coated plurality of multilayered core-shell structures, each multilayered core-shell structure of the plurality of multilayered core-shell structures has an amount of silicon at an outer-most surface thereof, wherein the amount of silicon at the outer- most surface is less than the amount of silicon at an outer surface of each multilayered core- shell structures that were coated with only the first and second sol-gel solutions and thermally treated.

20. The method of claim 19, wherein, for each multilayered core-shell structure comprising the third sol-gel solution, the amount of silicon at the outer-most surface is about 20 % or less of the total amount of silicon present in the respective multilayered core-shell structure.Atty. Docket No.: 037866-734001WO 21. The method of any one of claims 18 to 20, wherein the vanadium oxide is present in the third sol-gel solution in a third amount from about 1 weight percent to about 90 weight percent.

22. The method of claim any one of claims 18 to 21, wherein the vanadium oxide is present in the third sol-gel solution in a third amount that is equal to or greater than the first amount, the second amount, or both.

23. The method of claim any one of claims 18 to 21, wherein the vanadium oxide is present in the third sol-gel solution in a third amount that is less than the first amount, the second amount, or both.

24. The method of any one of claims 18 to 23, wherein each multilayered core-shell structure coated with the third sol-gel solution has a particle size from about 0.1 microns to about 100 microns.

25. The method of any one of claims 18 to 24, wherein the plurality of coating and thermal treating steps further comprises, coating, after coating at least a portion of the plurality of multilayered core-shell structures with the third sol-gel solution and thermal treating the partially coated multilayered core-shell structures, at least a portion of the plurality of multilayered core-shell structures with a fourth sol-gel solution and thermal treating the at least partially coated plurality of multilayered core-shell structures, the fourth sol-gel solution comprising vanadium oxide.

26. The method of claim 25, wherein the vanadium oxide is present in the fourth sol-gel solution in a fourth amount from about 1 weight percent to about 90 weight percent.

27. The method of claim 25 or claim 26, wherein the vanadium oxide is present in the fourth sol-gel solution in a fourth amount that is equal to or greater than at least one of the first amount, the second amount, or the third amount.

28. The method of claim 25 or claim 26, wherein the vanadium oxide is present in the fourth sol-gel solution in a fourth amount that is less than at least one of the first amount, the second amount, or the third amount.

29. The method of any one of claims 25 to 28, wherein after coating at least a portion of the plurality of multilayered core-shell structures with the fourth sol-gel solution and thermalAtty. Docket No.: 037866-734001WO treating the at least partially coated plurality of multilayered core-shell structures, each multilayered core-shell structure of the plurality of multilayered core-shell structures has an amount of silicon at an outer-most surface thereof, wherein the amount of silicon at the outer- most surface is less than the amount of silicon at an outer surface of each multilayered core- shell structures that were coated with only the first, second, and third sol-gel solutions and thermally treated.

30. The method of claim 29, wherein, for each multilayered core structure coated with the fourth sol-gel solution, the amount of silicon at the outer-most surface is about 5 % or less of the total amount of silicon present in the respective multilayered core-shell structure.

31. The method of any one of claims 25 to 30, wherein each multilayered core-shell structure of the plurality of multilayered core-shell structures coated with the fourth sol-gel solution has a particle size from about 0.1 microns to about 100 microns.

32. The method of any one of claims 25 to 31, wherein the plurality of coating and thermal treating steps further comprises, coating, after coating at least a portion of the plurality of multilayered core-shell structures with the fourth sol-gel solution, at least a portion of the plurality of multilayered core-shell structures with a fifth sol-gel solution and thermal treating the at least partially coated plurality of multilayered core-shell structures, the fifth sol-gel solution comprising vanadium oxide.

33. The method of claim 32, wherein the vanadium oxide is present in the fifth sol-gel solution in a fifth amount of from about 1 weight percent to about 90 weight percent.

34. The method of claim 32 or claim 33, wherein the vanadium oxide is present in the fifth sol-gel solution in a fifth amount that is equal to or greater than at least one of the first amount, the second amount, the third amount, or the fourth amount.

35. The method of claim 32 or claim 33, wherein the vanadium oxide is present in the fifth sol-gel solution in a fifth amount that is less than at least one of the first amount, the second amount, the third amount, or the fourth amount.

36. The method of any one of claims 32 to 35, wherein after coating at least a portion of the plurality of multilayered core-shell structures with the fifth sol-gel solution and thermalAtty. Docket No.: 037866-734001WO treating the at least partially coated plurality of multilayered core-shell structures, each multilayered core-shell structure of the plurality of multilayered core-shell structures has an amount of silicon at an outer-most surface thereof, wherein the amount of silicon at the outer- most surface is less than the amount of silicon at an outer surface of each multilayered core- shell structures that were coated with only the first, second, third, and fourth sol-gel solutions and thermally treated.

37. The method of claim 36, wherein, for each multilayered structure coated with the fifth sol-gel solution, the amount of silicon at the outer-most surface is about 1 % or less of the total amount of silicon present in the respective multi-layered core-shell structure.

38. The method of any one of claims 32 to 37, wherein each multilayered core-shell structure of the plurality of multilayered core-shell structures coated with the fifth sol-gel solution has a particle size from about 0.1 microns to about 100 microns.

39. The method of any one of claims 32 to 38, wherein each multilayered core-shell structure coated with the fifth sol-gel solution has a volumetric porosity from about 20 % to about 80 %.

40. The method of any one of claims 32 to 39, wherein the plurality of coating and thermal treating steps further comprises, coating, after coating at least a portion of the plurality of multilayered core-shell structures with the fifth sol-gel solution, at least a portion of the plurality of multilayered core-shell structures with one or more additional sol-gel solutions and, after each coating, thermal treating, the at least partially coated plurality of multilayered core-shell structures, the one or more additional sol-gel solutions comprising vanadium oxide.

41. The method of any one of the preceding claims, wherein the vanadium oxide comprises vanadium pentoxide (V2O5), vanadium dioxide (VO2), vanadium trioxide (V2O3), vanadium monoxide (VO), or any combination thereof.

42. The method of any one of the preceding claims, further comprising lithiating, after completing the plurality of coating and thermal treating steps, crystallized vanadium oxide of the plurality of multilayered core-shell structures, thereby generating the anode material, wherein each layer of a multilayered core-shell structure of the plurality of multilayered core- shell structures comprises lithium vanadium oxide material.Atty. Docket No.: 037866-734001WO 43. The method of claim 42, wherein lithiating crystallized vanadium oxide of the plurality of multilayered core-shell structures comprises lithiating the crystallized vanadium oxide of the plurality of multilayered core-shell structures with a lithium-containing reducing agent.

44. The method of claim 42 or claim 43, wherein the lithium vanadium oxide material has a formula LiaVbOc, wherein a = 0–10, b = 1–3, c = 1–9, and a, b, and c are selected to charge- balance the LiaVbOc.

45. The method of claim 42 or claim 43, wherein the lithium vanadium oxide material is doped with one or more dopants M, wherein the doped lithium vanadium oxide material has a formula LiaVbOcMd, wherein d = 0.1–3, and wherein a, b, c, and d are selected to charge- balance the LiaVbOcMd.

46. The method of any one of the preceding claims, wherein the first sol-gel solution, second sol-gel solution, the third sol-gel solution, the fourth sol-gel solution, the fifth sol-gel solution, or any combination thereof further comprises one or more dopants.

47. The method of claim 45 or claim 46, wherein the one or more dopants comprises B, Mg, Ca, Al, Ti, Nb, Ta, K, Na, Zn, Fe, Cu, Sc, Y, La, Si, Ge, Sn, Zr, Mn, P, Nb, Cr, Mo, W, Se, or any combination thereof.

48. The method of any one of the preceding claims, wherein each core structure of the plurality of core structures has a porosity of about 30 % or greater.

49. The method of any one of the preceding claims, further comprising ball-milling the plurality of core structures, prior to performing a plurality of coating and thermal treating steps.

50. The method of any one of the preceding claims, wherein the one or more carbon materials comprise single walled carbon nanotube, multi-walled carbon nanotubes, carbon fibers, carbon black, graphene, sp structure carbon, sp2 structure carbon, or sp3 structure carbon, or any combination thereof.

51. The method of any one of the preceding claims, wherein the at least one silicon particle has a particle geometry, the particle geometry comprising spheres, columns, cubes, cylinders, tubes, wires, sheets, fibers, irregular shapes, or any combination thereof.Atty. Docket No.: 037866-734001WO 52. The method of any one of the preceding claims, wherein thermal treating the partially coated silicon-carbon mixture comprises drying the partially coated silicon-carbon mixture at a first temperature from about 60 °C to about 200 °C, followed by drying at a second temperature from about 250 °C to about 500 °C.

53. The method of any one of the preceding claims, wherein thermal treating the at least partially coated plurality of core-shell structures comprises drying the at least partially coated plurality of core-shell structures at a first temperature from about 60 °C to about 200 °C, followed by drying at a second temperature from about 250 °C to about 500 °C.

54. The method of any one of claims 17 to 53, wherein thermal treating the at least partially coated plurality of multilayered core-shell structures comprises drying the at least partially coated plurality of multilayered core-shell structures at a first temperature from about 60 °C to about 200 °C, followed by drying at a second temperature from about 250 °C to about 500 °C.

55. An anode comprising: an anode material made by any one of the preceding claims.

56. A battery cell comprising an anode of claim 55.

57. The battery cell of claim 56, wherein the anode material is made by any one of claims 17 to 54, the battery is configured to be charged and discharged over at least 150 cycles.

58. The battery cell of claim 56, wherein the anode material is made by any one of claims 40 to 54, the battery is configured to be charged and discharged over at least 400 cycles.

59. A battery comprising one or more battery cells of any one of claims 56 to 58.

60. A method of manufacturing a battery cell, the battery comprising: casting a slurry on a negative current collector to form an anode on the negative current collector, the slurry comprising an anode material made by any one of claims 1 to 54; stacking a separator on the anode, wherein the separator includes an electrolyte; casting a cathode material on a positive current collector to form a cathode on the positive current collector; and stacking the cathode on the separator.Atty. Docket No.: 037866-734001WO 61. The method of claim 60, wherein the electrolyte comprises a liquid electrolyte, a polymer gel electrolyte, or a combination thereof.

62. A method of manufacturing a battery, the method comprising: providing one or more battery cells made by claim 60 or claim 61.

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