Lithium alloy anode for lithium-sulfur batteries

Abstract

Lithium-magnesium alloy anode and fluorinated ether electrolyte for lithium-sulfur batteries. The lithium-magnesium alloy anode contains about 90 wt% lithium and 10 wt% magnesium. The lithium-magnesium alloy anode includes at least one anode protective coating. The electrolyte contains about 0.4 M LiTFSi and about 2 wt% LiNO3 in a fluorinated ether solvent.

Description

[Technical Field]

[0001] Related applications This patent application claims priority to U.S. Provisional Patent Application No. 63 / 521,161, entitled “FREESTANDING LITHIUM-ALLOY ANODES FOR LITHIUM-SULFUR BATTERIES,” filed on 15 June 2023, U.S. Provisional Patent Application No. 63 / 539,050, entitled “FREESTANDING LITHIUM-ALLOY ANODES FOR LITHIUM-SULFUR BATTERIES,” filed on 18 September 2023, and U.S. Provisional Patent Application No. 63 / 658,047, entitled “LITHIUM-ALLOY ANODES FOR LITHIUM-SULFUR BATTERIES,” filed on 10 June 2024, all of which are assigned to the assignee of this specification. The disclosures of all prior applications, in their entirety, are deemed to be part of this patent application and are incorporated by reference herein.

[0002] This disclosure relates, in general, to batteries, and more specifically to lithium-sulfur batteries that can provide high specific energy and energy density combined with a long cycle life. [Background technology]

[0003] Recent battery developments will enable consumers to use high-specific-energy batteries, such as lithium-sulfur batteries, in many new applications. However, further improvements in battery technology are desirable. [Overview of the Initiative] [Means for solving the problem]

[0004] This summary is provided in a simplified form to introduce a selection of concepts that will be further described in the following modes for carrying out the invention. This summary is not intended to identify any important or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter.

[0005] In some embodiments, a self-supporting anode associated with a lithium-sulfur ("Li-S") battery may comprise a lithium-magnesium alloy and a polymer coating disposed on the self-supporting anode comprising one or more of polyvinylidene fluoride ("PVDF"), pentaerythritol tetraacrylate ("PETEA"), or polyethylene glycol dimethacrylate ("PEGDMA"), or a combination thereof. An exemplary lithium-magnesium alloy may comprise a 90 wt% lithium (Li)-10 wt% magnesium (Mg) alloy. The thickness of the self-supporting anode may be at least about 80 μm.

[0006] In some embodiments, the exemplary Li-Mg alloy may further include one or more of titanium, zirconium, zinc, calcium, gallium, aluminum, or indium as additional alloying elements. In some embodiments, the thickness of the polymer coating on the freestanding anode may be about 1 μm to about 10 μm.

[0007] In some other embodiments, another exemplary anode associated with a lithium-sulfur battery may include a reacted alloy layer disposed as a surface layer on the anode active material layer. A polymer coating may be disposed on the reacted alloy layer. Thus, the anode protective coating may include two or more layers, each layer characterized by its respective composition. In some embodiments, the exemplary reacted alloy layer may include an alloy of lithium with one or more of tin, indium, gallium, or aluminum. In some examples, the thickness of the reacted alloy layer may be less than 1 μm. In some other examples, the anode associated with a lithium-sulfur battery may include one or more of a freestanding anode or an anode supported on an anode current collector. In some embodiments, the exemplary polymer coating includes one or more of polyvinylidene fluoride ("PVDF"), pentaerythritol tetraacrylate ("PETEA"), or polyethylene glycol dimethacrylate ("PEGDMA"), or a combination thereof.

[0008] In some embodiments, another exemplary anode associated with a lithium-sulfur battery may include an anode active material layer and an anode protective coating disposed on the anode active material layer. The anode protective coating may contain an ionic liquid confined within a polymer matrix. In some examples, the anode active material layer may contain a 90 wt% Li-10 wt% Mg alloy. In some other examples, the polymer matrix may contain one or more acrylate groups or ethylene oxide groups. In some examples, the polymer matrix may contain one or more monomers or oligomers. In some embodiments, the thickness of the anode protective coating may be less than 10 μm. In some other embodiments, the amount of ionic liquid confined within the polymer matrix may be about 10 wt% to about 40 wt%.

[0009] In some embodiments, the lithium-sulfur battery may comprise a freestanding anode containing a 90 wt% Li-10 wt% Mg alloy, a polymer coating disposed on the freestanding anode containing one or more of PVDF, PETEA, or PEGDMA, or a combination thereof, a cathode, and a fluorinated ether electrolyte. In some embodiments, the fluorinated ether electrolyte may comprise about 50:25:25 (vol%) 1,2-dimethoxyethane ("DME"):1,3-dioxolane ("DOL"):bis(2,2,2-trifluoroethyl) ether ("BTFE"), about 0.4 M lithium bis(trifluoromethanesulfonyl) ("LiTFSI"), and about 2 wt% LiNO3. The thickness of the freestanding anode may be about 50 μm to about 200 μm.

[0010] In some embodiments, a self-supporting anode containing a Li-Mg alloy may further contain one or more of titanium, zirconium, zinc, calcium, gallium, aluminum, or indium as additional alloying elements. The Li-Mg alloy may contain about 90 wt% Li and about 10 wt% magnesium-aluminum-zinc alloy. In some embodiments, the magnesium-aluminum-zinc alloy may contain magnesium alloy AZ31. In some embodiments, the magnesium-aluminum-zinc alloy may contain magnesium alloy AZ61. In some embodiments, the Li-Mg alloy may contain about 90 wt% Li, about 5 wt% to about 9.5 wt% magnesium, and about 0.5 wt% to about 5 wt% aluminum.

[0011] In some embodiments, the cathode associated with a lithium-sulfur battery containing a self-supporting Li-Mg alloy anode may include one or more porous carbon layers containing sulfur deposited on a cathode substrate. The cathode substrate may include an aluminum current collector substrate. In some examples, the one or more porous carbon layers may include porous carbon aggregates of porous carbon primary nanoparticles. Each porous carbon primary nanoparticle may include an inner porous shell disposed around the center of the porous carbon primary nanoparticle and surrounding an inner porous carbon region, an outer porous shell surrounding an outer porous carbon region disposed between the inner and outer shells, and an interconnected porous network disposed within the inner and outer carbon regions and in fluid communication with them. The inner and outer carbon regions may be characterized by the average pore size and average pore density associated with each region. The average pore size may decrease along the radial direction from the center to the outer porous shell. In some other embodiments, the porous carbon primary nanoparticles may further include one or more intermediate porous shells disposed between the inner porous shell and the outer porous shell. Each of the intermediate porous shells may surround its respective intermediate porous carbon region.

[0012] In some embodiments, the porous carbon aggregate may comprise one or more interconnected bundles of conductive graphene layers. In some examples, the graphene layers may be arranged as one or more stacks connected to one another, defining a 3D porous scaffold structure containing mesopores. In some other examples, one or more stacks may be arranged substantially orthogonally to one another. In some examples, the graphene layers may be characterized by length dimensions of approximately 50 nm to 200 nm. In some other examples, the graphene layers may comprise one or more of single-layer graphene ("SLG"), single-layer graphene ("FLG"), or multi-layer graphene ("MLG"). In some embodiments, the porous carbon aggregate is characterized by an electrical conductivity of approximately 500 S / m to 20,000 S / m when compressed at a pressure of approximately 12,000 pounds per square inch (psi).

[0013] In some embodiments, the porous carbon aggregate has an I of about 0.95 to about 1.05 D / I G It can be characterized by a Raman spectroscopic signature having a ratio. In some embodiments, the sulfur-to-carbon weight ratio in one or more porous carbon layers in an exemplary Li-S battery cathode may be approximately 1:5 to 10:1. In some embodiments, the sulfur-to-carbon weight ratio may be about 3. In some other embodiments, the packing density of one or more porous carbon layers is at least 7 mg / cm³ 2 It is possible that in some embodiments, the thickness of one or more porous carbon layers may be about 10 μm to about 200 μm. In some embodiments, the average size of porous primary carbon nanoparticles may be about 20 nm to about 50 nm. In some examples, the average size of porous carbon aggregates may be about 50 nm to about 500 nm. In some other examples, the average size of porous carbon aggregates may be at least 1 μm.

[0014] In some embodiments, any one of the Li-S batteries described herein may include a separator disposed between the anode and the cathode. The separator may include a microporous monolayer polypropylene film. The separator may include a ceramic-coated material.

[0015] In some embodiments, the geometric shape of any one of the Li-S batteries described above may be cylindrical. The cylindrical battery may have a diameter of about 18 mm and a length of about 65 mm. In some embodiments, the cylindrical battery may have a diameter of about 21 mm and a length of about 70 mm. In some embodiments, the cylindrical battery may have a diameter of about 46 mm and a length of about 80 mm.

[0016] In some embodiments, a roll-to-roll method for forming one or more anode protective layers on an anode active material may include: placing one or more anode active material layers and one or more alloying metal layers as a feed material layer in a rolling mill; passing the feed material layer through the rolling mill, configured such that each surface of the one or more anode active material layers is in contact with one or more alloying metal layers in the rolling mill; and forming reacted alloy layers in situ on each surface of the anode active material layers during rolling. The reacted alloy layers may be reaction products of a reaction between one or more anode active material layers and one or more alloying metal layers.

[0017] In some embodiments, a method for forming one or more protective layers on an anode active material may include forming a reacted alloy layer on each surface of the anode active material using one of the methods described herein, and depositing a polymer coating on the reacted alloy layer formed on each surface of the anode active material. In some embodiments, the thickness of the reacted alloy layer may be less than 1 μm. In some other embodiments, the polymer coating may include one or more of pentaerythritol tetraacrylate ("PETEA") or polyethylene glycol dimethacrylate ("PEGDMA"). In some embodiments, the thickness of the polymer coating may be less than 1 μm.

[0018] In some embodiments, a method for distributing an anode protective coating on an anode associated with a lithium-sulfur battery may begin with preparing a coating solution by mixing a precursor comprising one or more monomers or oligomers, an ionic liquid, one or more lithium salts, and a polymerization initiator in a solvent. The operation may continue by applying the coating solution to the anode and initiating the polymerization of the one or more monomers or oligomers. Excess solvent may be removed by drying. The operation may continue by curing the coating to form a polymer matrix implanted with the ionic liquid. In some examples, the amount of precursor in the coating solution is about 3% to about 30% by weight. In some other examples, the amount of polymer matrix implanted with the ionic liquid applied to the anode is about 10 μg / cm³. 2 ~about 600μg / cm 2 It is possible.

[0019] Details of one or more embodiments of the subject matter described herein are given in the accompanying drawings and in the following description. Other features, aspects, and advantages will become apparent from the description, drawings, and claims. Note that the relative dimensions in the following figures may not be to scale. [Brief explanation of the drawing]

[0020] [Figure 1A] Schematic diagrams of exemplary porous carbon primary nanoparticles according to several embodiments are shown. [Figure 1B] Transmission electron microscope (TEM) images showing aggregates of porous carbon primary nanoparticles according to several embodiments are shown. [Figure 1C] TEM images of aggregates of porous carbon primary nanoparticles according to several embodiments are shown. [Figure 1D] TEM images of surface-etched aggregates of porous carbon primary nanoparticles according to several embodiments are shown. [Figure 2] A schematic diagram of another exemplary porous carbon primary nanoparticle according to several embodiments is shown. [Figure 3A] Schematic diagrams of mesoporous carbon nanoparticles according to several embodiments are shown. [Figure 3B] Scanning electron microscope (SEM) images of aggregates of porous carbon primary nanoparticles according to several embodiments are shown. [Figure 3C] TEM micrographs of aggregates of porous carbon primary nanoparticles according to several embodiments are shown. [Figure 4] Schematic diagrams illustrating exemplary lithium-sulfur cylindrical batteries in several embodiments are shown. [Figure 5A] Schematic diagrams of lithium-sulfur battery anodes, including one or more protective layers disposed on the anode active material layer, according to several embodiments, are shown. [Figure 5B] Schematic diagrams of lithium-sulfur pouch cell anodes, including one or more protective layers, according to several embodiments are shown. [Figure 6A] Schematic diagrams of exemplary roll-to-roll continuous methods for forming a lithium anode active material layer sandwiched between reacted alloy layers, according to several embodiments, are shown. [Figure 6B] Schematic diagrams of exemplary roll-to-roll continuous methods for forming a reacted alloy layer on an anode supported on a current collector, according to several embodiments, are shown. [Figure 7] The following plots illustrate the cycle-dependent performance data of self-supporting anodes containing a Li-Mg alloy in half-shaped or symmetrical lithium-sulfur battery cells, according to several embodiments. [Figure 8A] The following plots illustrate the formation cycle data of a self-supporting anode containing a Li-Mg alloy in an exemplary lithium-sulfur coin cell, according to several embodiments. [Figure 8B] The following plots illustrate the formation cycle data of a self-supporting anode containing a Li-Mg alloy in an exemplary lithium-sulfur coin cell, according to several embodiments. [Figure 8C]The following plots illustrate the formation cycle data of a self-supporting anode containing a Li-Mg alloy in an exemplary lithium-sulfur coin cell, according to several embodiments. [Figure 8D] The following plots illustrate the estimation of discharge capacity as a function of the lithium content remaining in the self-contained anode containing a Li-Mg alloy after a single discharge in a lithium-sulfur battery, according to several embodiments. [Figure 9] The following plots illustrate the cathode discharge capacity and capacity retention of exemplary lithium-sulfur ("Li-S") coin cells, including a self-supporting anode containing a Li-Mg alloy, according to several embodiments. [Figure 10] The following plots illustrate the performance of Li-S coin cells at various magnesium concentrations in self-supporting anodes containing Li-Mg alloys, according to several embodiments. [Figure 11] The following plots illustrate the cathode discharge capacity and capacity retention of a self-supporting anode of a Li-S coin cell containing a Li-Mg alloy in several embodiments. [Figure 12A] SEM micrographs of the surface of a self-supporting Li-Mg alloy anode, taken from a lithium-sulfur coin cell after the initial discharge, are shown in several embodiments. [Figure 12B] SEM micrographs of cross-sections of self-supporting Li-Mg alloy anodes taken from lithium-sulfur coin cells after the initial discharge, according to several embodiments, are shown. [Figure 12C] Cross-sectional SEM micrographs of self-supporting Li-Mg alloy anodes after initial discharge, using energy-dispersive X-ray spectroscopy (EDS) elemental analysis, are shown for several embodiments. [Figure 13] The following plots illustrate the cathode discharge capacity and capacity retention of exemplary lithium-sulfur pouch cells, including a self-supporting Li-Mg alloy anode, according to several embodiments. [Figure 14A] The following plots illustrate the cathode discharge capacity and capacity retention of lithium-sulfur coin cells having a quaternary self-supporting Li-Mg alloy anode in several embodiments. [Figure 14B] The following plots illustrate the cathode discharge capacity and capacity retention of lithium-sulfur coin cells having a quaternary self-supporting Li-Mg alloy anode in several embodiments. [Figure 15] The following plots illustrate the Coulomb efficiency and discharge capacity retention of lithium-sulfur coin cells containing a ternary self-supporting Li-Mg alloy anode in several embodiments. [Figure 16A] The following plots illustrate the cathode discharge capacity and capacity retention of lithium-sulfur coin cells containing a self-supporting Li-Mg alloy anode with a protective anode layer, according to several embodiments. [Figure 16B] The following plots illustrate the cycle lifetime and total energy delivered as a function of capacity retention for lithium-sulfur coin cells containing a self-supporting Li-Mg alloy anode with a protective coating, according to several embodiments. [Figure 17] The following plots illustrate the cathode discharge capacity and capacity retention of lithium-sulfur coin cells, including a 90Li-Mg alloy anode with at least one protective layer, according to several embodiments. [Figure 18] The following plots illustrate the cathode discharge capacity and capacity retention of lithium-sulfur coin cells, including anode protective coatings, according to several embodiments. [Figure 19] The following plots illustrate the retention of discharge capacity in lithium-sulfur coin cells, including anode protective coatings, according to several embodiments.

[0021] Similar reference numbers and reference symbols in various drawings indicate the same elements. [Modes for carrying out the invention]

[0022] The following description covers several exemplary embodiments for the purpose of illustrating the innovative aspects of the disclosure. However, those skilled in the art will readily recognize that the teachings herein can be applied in numerous different ways. The embodiments described may be implemented in batteries for various applications and may be adapted to compensate for various performance-related deficiencies. Accordingly, the embodiments disclosed should not be limited to the examples provided herein, but rather encompass all embodiments intended by the appended claims. Furthermore, well-known elements of the disclosure will not be described in detail or will be omitted so as not to obscure the relevant details of the disclosure.

[0023] Various embodiments of novel compositions and methods are described more fully herein with reference to the accompanying drawings. These embodiments are provided to ensure that this disclosure is thorough and complete and fully conveys the scope of this disclosure to those skilled in the art. While several examples and embodiments are described herein, many variations and permutations of these examples fall within the scope of this disclosure. While some advantages and benefits of various embodiments are mentioned, the scope of this disclosure is not intended to be limited to advantages, uses, or purposes. The detailed description and drawings are not limiting and are merely illustrative of this disclosure, and the scope of this disclosure is defined by the accompanying claims and their equivalents.

[0024] In this disclosure, primary carbon nanoparticles may be considered as non-discrete components or constituent units of a spherical aggregate, and are separable from the aggregate only by crushing. Multiple primary carbon nanoparticles produced by one or more methods, including the thermal decomposition of hydrocarbon gases, may be accreted or bonded to form an aggregate of primary carbon nanoparticles. The carbon aggregate may be considered as a discrete colloidal entity, the smallest dispersible unit composed of accreted primary carbon nanoparticles. Primary carbon nanoparticles may be joined together by one or more of van der Waals forces, covalent bonds, ionic bonds, metallic bonds, or other physical or chemical interactions. Multiple aggregates may be considered as a single aggregate. Aggregates of primary carbon nanoparticles may be produced from one or more methods, including the thermal decomposition of hydrocarbon gases. An exemplary porous carbon aggregate of primary carbon nanoparticles may be characterized by a major dimension of at least about 1 μm.

[0025] In this disclosure, “graphene” refers to an allotrope of carbon in the form of an atomic-scale hexagonal lattice, where one atom forms each vertex. The carbon atoms in graphene are sp 2 It can be a hybrid of carbon atoms. Furthermore, graphene is approximately 1580 cm³. -1 G-mode, and approximately 1350cm -1 It has a Raman spectrum with two main peaks, which is in D-mode (when using a 532 nm excitation laser). As used herein, the term carbonaceous material may refer to a material that contains or is formed of one or more types or compositions of carbon.

[0026] The commercialization of lithium-sulfur (「Li-S」) batteries is hindered by a limited number of charge-discharge cycles, approximately less than 100 cycles. Root cause analysis suggests that Li metal anode failure is the main cause of cell failure. During cycling, the Li metal anode experiences significant volume changes caused by repeated stripping (during discharge) and plating (during charge) of lithium. This volume change affects the stability of the anode, particularly that of unsupported (or free-standing) Li metal anodes. In a free-standing Li metal anode, the anode is not supported on a metal substrate such as a copper current collector. Lithium has a high oxidation potential (about 3.04V) and can react with almost any electrolyte solution in either solvent or salt form to form a solid electrolyte interphase (「SEI」) layer, so the stability of the anode is further affected by an unstable electrode-electrolyte interface and anode pulverization caused by volume changes during cycling.

[0027] The SEI layer is electronically insulating but Li +It is ion-conductive for ions. Thus, once the SEI layer is formed, additional undesirable reactions between the Li metal anode and the electrolyte can be blocked or partially blocked by the SEI layer. However, the SEI layer is generally non-uniform, which results in a non-uniform current distribution during plating and may cause uneven (or non-uniform) lithium deposition and anode cracking during cycling. Exposure of the fresh lithium metal anode to the electrolyte may lead to undesirable consumption of lithium for reformation of the SEI layer. Local non-uniform lithium deposition and peeling may appear as dendritic crystals during plating and pits during peeling at the anode during charge-discharge cycles. Dendritic crystals can cause serious safety problems and may reduce the cycle performance of lithium-ion batteries. Furthermore, dendritic crystals may be removed from the anode to form a "dead" zone of lithium. Lithium dendritic crystals can penetrate through a polyolefin separator or even a polymer / solid electrolyte separator disposed between the anode and cathode of the battery, which may adversely affect the safety and performance of Li-ion batteries.

[0028] The above problems are further exacerbated in Li-S batteries containing sulfur trapped within a porous carbon cathode as the active cathode material. Sulfur reacts with lithium ions that form polysulfides. During the discharge cycle, Li ions move from the anode to the cathode through an electrolyte in which sulfur is reduced to lithium sulfide (Li2S). The reduction of sulfur to Li2S is complex and may involve the formation of several intermediate Li polysulfides (Li2S x , 8 < x < 1). Polysulfides ("Li-PS") can be formed as follows during the battery discharge cycle.

Number

[0029] Ideally, Li-PS compounds oxidize back to sulfur during the charging cycle. In reality, Li-PS compounds leak from the porous carbon cathode because they are highly soluble in the electrolyte, which leads to sulfur loss and a decrease in cathode capacity. While sulfur and Li2S are relatively insoluble in most electrolytes, many intermediate polysulfides ("Li-PS") are soluble, causing irreversible loss of active sulfur from the cathode. Dissolving Li-PS in the electrolyte requires a large amount of electrolyte (E / S > 3), reducing the battery's specific energy. Higher polysulfides (Li2S8 and Li2S6) may diffuse into the anode and be reduced to lower polysulfides (Li2S6 and Li2S4), which are then oxidized in the cathode. At the anode, polysulfides participate in SEI formation, increasing SEI irregularities and exacerbating corrosion of the Li metal anode. This cyclic process, commonly known as the polysulfide "shuttle effect," leads to a decrease in Coulomb efficiency and gradual leakage of active sulfur material from the cathode, which also reduces the battery's lifecycle. Furthermore, elemental sulfur in Li2S x The conversion to sulfur compounds involves a significant volume expansion at the cathode (which can reach up to 80%), which exposes the cathode to considerable mechanical stress, leading to rapid cathode degradation.

[0030] Furthermore, the "shuttle effect" causes self-discharge in Li-S batteries during battery idle due to the slow dissolution of Li-PS. Battery self-discharge shortens battery life and poses safety problems. Repeated volume changes and corrosion reactions at the anode continuously consume active Li, forming large amounts of "dead Li" that can separate during the cycle, reducing the recyclability of Li-S batteries. As mentioned above, the anode often contributes to cell failure either through electrolyte consumption of Li due to corrosion or Li depletion during the cycle. These challenges limit the commercial viability of high specific energy Li-S batteries with high-density cathodes, limited electrolytes, and limited anode capacity (or low N / P ratio). The N / P ratio can be defined as the ratio of the reversible capacity (mAh) of the negative electrode (anode) to the reversible capacity (mAh) of the positive electrode (cathode), assuming full utilization of sulfur.

[0031] Therefore, an excess amount of electrolyte is used in Li-S batteries to mitigate conductivity losses due to dissolved Li-PS. Furthermore, an excess of lithium metal is required in the anode to mitigate lithium metal losses due to SEI formation, pit formation, and dendritic crystal formation. These requirements prevent Li-S batteries from reaching or attempting to exceed a specific energy target of 500 W-h / kg. Li-S batteries generally require an electrolyte-to-sulfur ratio ("E / S ratio") of approximately 5 μL / mgS and an N / P ratio greater than 2. For comparison, the N / P ratio of commercial Li-ion batteries is approximately 1.03-1.2. The N / P ratio is important to offset the potential for higher anode material losses during the cycle, but also to reduce area capacity (mAh / cm²). 2 ) is also important for reducing current density, and therefore the failure rate on the anode.

[0032] Li-S anodes generally use current collectors such as copper as anode supports. Copper significantly increases the weight of Li-S batteries and reduces their specific energy. Copper is also susceptible to corrosion by polysulfides. Therefore, there is great interest in developing substrate-less or self-supporting anodes. However, self-supporting anodes in Li-S batteries are difficult due to morphological and instability issues associated with lithium metal (100% lithium) anodes. Li-S batteries require self-supporting anode alloy compositions that are stable under cycle conditions and have a low E / S ratio of approximately 5 or less for coin cells and 3 or less for pouch cells. Li-S batteries also require self-supporting anode compositions that are stable under cycle conditions, have an N / P ratio of approximately less than 2, and achieve a battery specific energy of 500 W-h / kg.

[0033] In some embodiments, a Li alloy can be used as a self-supporting anode instead of a pure lithium metal anode to overcome the aforementioned anode instability problems associated with volume changes during the cycle and the high reactivity of the Li metal anode with the electrolyte and polysulfide. Lithium can be alloyed with several metals, including one or more of silicon, tin, magnesium, or aluminum. Li alloy anodes may have a higher electrode potential compared to lithium deposits and may prevent corrosion at the anode caused by reactions between the anode and the polysulfide and electrolyte. On the other hand, the alloying element may act as a lithium host for lithium deposition or plating (during the charging cycle), absorbing volume changes during the cycle and helping to stabilize the anode. The alloying element may form a stable surface thin film on the anode, which may reduce the uneven deposition of lithium during plating.

[0034] Some alloying elements with lithium may reduce the Li-S battery capacity (mAh) or voltage, and subsequently the battery specific energy. Furthermore, some alloying elements, such as silicon (Si), tin (Sn), and germanium (Ge), can undergo drastic volume changes during lithiation (plating, during charging cycles) and delithiation (stripping during discharge), and may not be suitable candidates for Li-S battery anodes. With elements such as silicon and tin, lithium... x M y It can form intermetallic compounds of a certain type, which have a high degree of ionic bonding and are subsequently brittle and fragile. Some other lithium alloys, such as lithium-aluminum alloys, are reversible only within a limited composition range and may not be suitable for Li-S battery applications.

[0035] In some embodiments, alloying lithium with a small amount of magnesium (Mg) can improve the stability of the Li-S battery anode against reactions with the electrolyte and polysulfide, thereby increasing battery cycle life. In lithium-magnesium ("Li-Mg") alloy anodes, the magnesium alloying element can provide structural integrity to the anode during volume changes associated with the course of the battery cycle, as magnesium does not undergo delamination and plating at the anode. Furthermore, alloying lithium with a small amount of magnesium enables a self-contained anode design (without requiring a copper current collector substrate), which also increases the battery specific energy.

[0036] Li and Mg have equivalent atomic radii and form a single solid-phase body-centered cubic structure (also referred to herein as a BCC structure) that extends over a wide compositional range of approximately 11.5–100 wt% lithium in the Li-Mg alloy. Therefore, the capacity of the Li-Mg alloy anode can be tuned over a wide range without considering any alloy phase changes. The Li-Mg alloy is used during the charge-discharge cycle of a Li-S battery. +A scaffold-like structure can be provided that facilitates the insertion and removal of ions. The volume change associated with the insertion of 1 mole of Li into Mg can be approximately 80% when calculated using Li-Mg alloy lattice parameters, which is much lower than the volume change associated with the interaction of lithium with other alloying elements such as silicon, tin, and antimony. Li-Mg alloys are highly ductile, which allows for the simple and straightforward fabrication of electrodes by rolling and annealing. In compositions that are approximately 90% Li-rich, no loss of battery voltage is observed when replacing a Li anode (100% lithium) with a Li-Mg anode, as lithium stripping and plating may occur near 0V. Furthermore, since magnesium is lithium-philic, dispersed magnesium in the Li-Mg anode can function as nucleation sites for uniform lithium deposition during charging cycles.

[0037] Because Li-Mg alloy anodes form a relatively stable SEI interface (compared to Li anodes), a relatively smooth anode surface morphology can be achieved during the cycle operation of Li-S batteries. Furthermore, Li-Mg alloy matrices with low lithium content and high electrical and ionic conductivity can be formed after Li stripping to provide excellent anode current collectors and hosts for subsequent Li plating. Thus, Li-Mg alloy anodes can be self-supporting and may not require a separate anode current collector.

[0038] In some embodiments, lithium-rich Li-Mg alloys containing at least approximately 90 wt% Li (at least about 72 wt% Li) can be used as durable, self-contained Li-Mg anodes for Li-S batteries. Increasing the magnesium content of Li-Mg alloy anodes to achieve high anode capacity is undesirable because it may require an increased number of activation cycles. Furthermore, increasing the magnesium content in Li-Mg alloys may cause workability problems during anode fabrication due to the increased hardness of magnesium.

[0039] In some embodiments, the exemplary Li-Mg alloy freestanding anode in a Li-S battery may contain about 90 wt% lithium and about 10 wt% magnesium (hereinafter referred to as "90 wt% Li:10 wt% Mg" or "90Li-Mg alloy"). For clarity, the 90Li-Mg alloy contains about 97 wt% Li and about 3 wt% Mg.

[0040] Without being constrained by any particular theory, improving the cycle life of Li-S batteries beyond 200 cycles and with high battery specific energy (500 W-h / kg) may require a synergistic interaction between a Li alloy anode capable of operating at an N / P ratio of less than approximately 2 and a suitable electrolyte that reduces electrolyte consumption and enables battery operation at an E / S ratio of less than approximately 5 μL / mg.

[0041] In some embodiments, the Li-S battery may include a self-supporting anode comprising a Li-Mg alloy, a polymer coating disposed on the self-supporting anode, a cathode, and a fluorinated ether electrolyte disposed in contact with the self-supporting anode and the cathode. In some embodiments, the electrolyte may include one or more of lithium nitrate (LiNO3) or lithium bis(trifluoromethanesulfonyl)imide ("LiTFSI").

[0042] In some embodiments of exemplary Li-S batteries including a Li-Mg alloy self-supporting anode, the concentration of LiTFSI in the liquid fluorinated ether electrolyte may be about 0.1 M to about 2 M. In some embodiments, the concentration of LiNO3 in the liquid fluorinated ether electrolyte may be about 2% by weight to about 6% by weight. In some other embodiments of exemplary Li-S batteries including a Li-Mg alloy self-supporting anode, the magnesium content in the Li-Mg alloy may be about 5% by weight to about 15% by weight. In some embodiments, the Li-Mg alloy may contain about 90% by weight of lithium and about 10% by weight of magnesium.

[0043] In some embodiments, the thickness of the freestanding anode containing the Li-Mg alloy may be about 50 μm to about 200 μm. In some embodiments, the polymer coating disposed on the freestanding anode may include polyvinylidene fluoride ("PVDF").

[0044] In some embodiments, the exemplary liquid fluorinated ether electrolyte in a Li-S battery containing a Li-Mg alloy self-supporting anode may comprise about 50:25:25 (vol%) of 1,2-dimethoxyethane ("DME"):1,3-dioxolane ("DOL"):bis(2,2,2-trifluoroethyl) ether ("BTFE"), about 0.4 M LiTFSI, and about 2 wt% LiNO3. In some other embodiments, the exemplary liquid fluorinated ether electrolyte in a Li-S battery containing a Li-Mg alloy self-supporting anode may comprise about 50:25:25 (vol%) of DME:DOL:(1,1,2,2-tetraethoxyethane) ("TEE"), about 0.4 M LiTFSI, and about 2 wt% LiNO3.

[0045] In some embodiments, the exemplary electrolyte may comprise about 50:25:25 (vol%) DME:DOL:1,1,2,2-tetrafluoroethyl 2,2,2-trifluoroethyl ether ("TFETFE"), about 0.4 M LiTFSI, and about 2 wt% LiNO3. In some other embodiments, the exemplary electrolyte may comprise about 60:20:10:10 (vol%) DME:DOL:TEE:TFETFE, about 0.4 M LiTFSI, and about 2 wt% LiNO3.

[0046] In some embodiments, the exemplary electrolyte may comprise about 50:25:25 (vol%) DME:DOL:1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether ("TTE"), about 0.4 M LiTFSI, and about 2 wt% LiNO3. In some embodiments, the exemplary electrolyte for use with a Li-Mg alloy anode in a Li-S battery may comprise LiTFSI at a concentration of about 0.1 M to about 1 M, and LiNO3 at a concentration of about 1 wt% to 6 wt%. In some other embodiments, the exemplary electrolyte may comprise about 50:25:25 (vol%) DME:DOL:1-fluorinated 1,4-dimethoxylbutane (FDMB), about 0.4 M LiTFSI, and about 2 wt% LiNO3. In some other embodiments, the electrolyte may comprise about 1.0 M LiTFSI in about 50:50 (vol%) DOL:BTFE.

[0047] Additives in the electrolyte, such as lithium nitrate (LiNO3), dissociate into lithium cations (Li + ) can be generated. Alternatively, additives such as LiTFSI in the electrolyte may dissociate to form lithium cations (Li + ) and TFSI - Anions may be generated. Additives in the electrolyte that can dissociate into lithium ions may also include one or more of the following: lithium lanthanum zirconium oxide ("LLZO"), oxynitrides (e.g., lithium phosphate nitride or "LIPON"), NASICON-type conductors (e.g., lithium aluminum titanium phosphate), or lithium tin sulfide ("LSPS").

[0048] In some exemplary embodiments of Li-S batteries, the alloying elements in the Li-Mg alloy anode may include additional alloying elements to improve cycle-dependent stability without significantly sacrificing specific energy. Specifically, using additional alloying elements in the Li-Mg alloy anode, approximately 200 cycles can be achieved with a discharge capacity of at least 400 mAh / g (or approximately 600 mAh / g sulfur) with a capacity retention of over 80%. In some embodiments, the anode in the Li-S battery may include a ternary alloy (e.g., an alloy in the form of Li-Mg-x) or a quaternary alloy (e.g., an alloy in the form of Li-Mg-xy). In exemplary Li-Mg-xy alloys, the "x" and "y" alloying elements may include one or more of titanium, zirconium, zinc, calcium, gallium, aluminum, or indium. Without being constrained by any particular theory, ternary or quaternary alloys may provide more stable SEI formation at the anode.

[0049] In some embodiments, exemplary alloying elements for lithium alloy self-supporting anodes may include magnesium-aluminum-zinc alloys. In some embodiments, a Li alloy self-supporting anode may contain about 90 wt% Li and about 10 wt% magnesium-aluminum-zinc alloy. In some embodiments, the magnesium-aluminum-zinc alloy may include magnesium alloy AZ31. Magnesium alloy AZ31 contains about 94.5 wt% to about 97 wt% magnesium, about 2.5 wt% to about 3.5 wt% aluminum, about 0.6 wt% to about 1.4 wt% zinc, less than about 0.3 wt% silicon, and less than about 0.2 wt% manganese.

[0050] In some embodiments, an exemplary Li-alloy self-supporting anode for a Li-S battery may comprise about 90 wt% lithium and about 10 wt% magnesium alloy AZ31 ("90Li-AZ31"). In some embodiments, the magnesium-aluminum-zinc alloy comprises magnesium alloy AZ61. Magnesium alloy AZ61 comprises about 92 wt% to about 93 wt% magnesium, about 5.8 wt% to about 7.2 wt% aluminum, about 0.4 wt% to about 1.5 wt% zinc, about 0.1 wt% silicon, about 0.15 wt% manganese, about 0.05 wt% copper, and less than about 0.01 wt% nickel, calcium, and iron.

[0051] An exemplary Li-alloy anode for a Li-S battery may contain about 90 wt% lithium and about 10 wt% magnesium alloy AZ61 ("90Li-AZ61"). In some examples, an exemplary Li-alloy freestanding anode for a Li-S battery may contain magnesium and aluminum as alloying elements. In other examples, an exemplary Li-Mg-Al alloy anode may contain about 90 wt% Li, about 5 wt% to 9.5 wt% Mg, and about 0.5 wt% to 5 wt% Al. In some other examples, an exemplary Li-Mg-Al alloy anode may contain about 90 wt% Li, about 5 wt% Mg, and about 5 wt% Al. In some other examples, an exemplary Li-Mg-Al alloy anode may contain about 90 wt% Li, about 8 wt% Mg, and about 2 wt% Al. In some embodiments, the exemplary Li-Mg-Al alloy anode may contain about 90 wt% Li, about 9.5 wt% Mg, and about 0.5 wt% Al.

[0052] In some exemplary embodiments, one of the aforementioned self-supporting Li-Mg alloy anodes may be coated with a surface coating that reacts with lithium in the alloy to form a protective layer and further improves the stability of the anode over the course of the cycle. In some embodiments, the surface coating for the self-supporting Li-Mg alloy anode may include a polyvinylidene fluoride ("PVDF") coating layer. The thickness of the PVDF coating layer may be about 1 μm to about 10 μm.

[0053] Without being constrained by any particular theory, PVDF reacts with lithium in a self-supporting Li-Mg alloy anode to disperse LiF in a polymer matrix. - Ions may be formed. The protective layer allows lithium ions (Li) to be released from and to the anode during the cycle. + ) may improve transport and / or be associated with it. Reducing lithium-containing dendritic growth from the anode of a Li-S battery may increase charge rate, discharge rate, energy density, cycle life, or any combination thereof. The polymer matrix is ​​produced by the dissociation of additives such as LiTFSI in the electrolyte. - It can partially capture anions.

[0054] In some embodiments, the surface coating for the self-supporting Li-Mg alloy anode may comprise one or more of pentaerythritol tetraacrylate ("PETEA") or polyethylene glycol dimethacrylate ("PEGDMA"). The thickness of the coating layer may be about 1 μm to about 10 μm. In other embodiments, the surface coating for the self-supporting Li-Mg alloy anode may comprise PETEA and PEGDMA. The thickness of the coating layer may be about 1 μm to about 10 μm. In some other embodiments, an exemplary Li-S battery may comprise a self-supporting 90 Li-Mg alloy anode, a polymer coating comprising one or more of PETEA or PEGDMA disposed on the self-supporting anode, and a fluorinated ether electrolyte in contact with the anode. An exemplary fluorinated ether electrolyte may comprise 50:25:25 (vol%) 1,2-dimethoxyethane ("DME"):1,3-dioxolane ("DOL"):bis(2,2,2-trifluoroethyl) ether ("BTFE"), and may also comprise about 2 wt% LiNO3 and 0.4 M LiTFSI. In some embodiments, the thickness of the freestanding anode may be about 100 μm.

[0055] In some embodiments, one of the aforementioned self-supporting lithium metal or lithium alloy anodes may include a reacted alloy layer disposed between an anode active material layer (e.g., a Li-Mg alloy) and a protective polymer coating disposed on the anode active material layer. Examples of protective polymer coatings for self-supporting anodes have been previously described herein. The reacted alloy layer may be formed as a reaction product of an anode active material layer having an alloyed metal layer. Without being constrained by any particular theory, the reacted alloy layer blocks the polysulfide from reaching the anode active material layer, while Li + The reacted alloy layer may be selectively conductive to ions. The reacted alloy layer may also be stable to various lithium-sulfur battery electrolyte compositions previously described herein. Thus, one or more of the reacted alloy layers or protective polymer coatings may function as an anode protective layer in a self-supporting lithium metal or lithium alloy anode, improving the lifespan and stability of the anode in lithium-ion batteries and / or lithium-sulfur batteries.

[0056] In some embodiments, the cathode associated with any one of the Li-S batteries, including a self-supporting Li-Mg alloy anode, may comprise one or more carbon layers or thin films of aggregates of primary carbon nanoparticles (described below) disposed on a substrate such as aluminum. An exemplary coating amount of the cathode material, comprising a carbonaceous substance, sulfur, and a binder, onto the substrate is approximately 5 g / cm². 2 ~about 10mg / cm 2 This is possible. By adjusting the porosity and surface area of ​​the carbon cathode, the desired balance can be achieved between increasing the amount of sulfur coating and inhibiting the migration of polysulfides to and / or throughout the electrolyte.

[0057] Figure 1A shows schematic diagram 100A of exemplary porous primary carbon nanoparticles 105 according to several embodiments. In some embodiments, the porous primary carbon nanoparticles 105 may resemble carbon nanoonions ("CNO"). As shown in the example in Figure 1A, the porous primary carbon nanoparticles 105 may include a core (inner) porous carbon region 111 defined by a first porosity and surrounded within an inner porous shell 113. This inner porous carbon region 111 may also be referred to herein as the first porous region and may include a plurality of first pores 101 dispersed therein. An outer porous carbon region 112, also referred to herein as the second porous region, may be located between the inner porous shell 113 and the outer porous shell 110 and may include a plurality of second pores 102 dispersed therein. The inner porous carbon region 111 and the outer porous carbon region 112 may be interconnected by one or more of the first pores 101 or one or more of the second pores 102, thereby interconnecting the first and second porous regions. That is, the inner porous carbon region 111 may be configured to be in fluid communication with the outer porous carbon region 112 through the interconnected porous network. The inner porous carbon region 111 may be defined by a first pore density, and the outer porous carbon region 112 may be defined by a second pore density similar to or different from the first pore density.

[0058] Exemplary porous primary carbon nanoparticles 105 may be characterized by an average size or major dimensions (diameter, length, width) of less than approximately 200 nm. In some embodiments, the average pore size may gradually decrease along the radial direction from the center 116 of the nanoparticle 105 to the outer boundary 113 of the nanoparticle 105. In some other embodiments, the porous primary carbon nanoparticles 105 may be characterized by the range of pore size and pore distribution in each region. A first pore 101 may be configured to hold polysulfide 120, and a second pore 102 may provide a pathway or channel for the transport of lithium ions (not shown for simplicity) to and from the porous primary carbon nanoparticles 105, and for the pre-coating of sulfur 124 to the nanoparticles.

[0059] Figure 1B shows a transmission electron microscope ("TEM") image 100B of an aggregate 140 of porous primary nanoparticles 105 according to several embodiments. Those skilled in the art will understand that the image is shown only as an example and other scales may exist without departing from the scope and spirit of this embodiment. The exemplary carbon aggregate 140 may include an interconnected porous network arranged between adjacent carbon nanoparticles 105. The aggregate 140 may contain multiple porous carbon primary nanoparticles 105, which in some examples may resemble a "thread of pearls". In some embodiments, the size or main dimension of the aggregate 140 may be about 50 nm to 500 nm.

[0060] Figure 1C shows TEM images 100C of aggregates 145 of porous primary carbon nanoparticles 105 according to several embodiments. Aggregates 145 of porous primary carbon nanoparticles 105 are approximately 3000 m 2 It may be characterized by a surface area of ​​less than / g. In some embodiments, the exemplary aggregate 145 may be spherical. In some embodiments, the aggregate 145 may be of any shape, including one or more of spherical, spheroidal, dumbbell-shaped, cylindrical, elongated cylindrical, rectangular prism-shaped, disc-shaped, wire-shaped, or irregular.

[0061] Figure 1D shows TEM images 100D of surface-etched aggregates 142 of porous primary carbon nanoparticles according to several embodiments. An exemplary aggregate 145 may be surface-etched using a method including CO2 etching to create pores on the outer surface of aggregate 145, increasing the surface area of ​​carbon aggregate 145 and resulting in surface-etched aggregates 142. After etching, surface-etched aggregates 142 may contain three-dimensional graphene carbon ("3DG carbon"), which includes graphene layers interconnected as a three-dimensional ("3D") graphene structure (not shown for simplification). Surface-etched aggregates 142 of porous primary carbon nanoparticles have an I of approximately 0.95–1.05 D / I GIt can be characterized by a Raman spectroscopic signature with a ratio. Surface-etched aggregates 142 can be assembled as rigid porous carbon aggregates by a process including spray drying.

[0062] Figure 2 shows a schematic diagram 200 of another exemplary porous primary carbon nanoparticle 205 according to several embodiments. The exemplary triple-zone porous primary nanoparticle 205 may include a first core (inner) carbon zone or region 251 nested within a second intermediate carbon zone or region 252, the second intermediate carbon zone or region 252 in turn nested within a third outer carbon zone or region 253. The exemplary first zone 251 may include pores 261 having an average size or major dimensions (diameter, length-width) of approximately 40 nm or less, the second zone 252 may include pores 262 having an average size or major dimensions (diameter, length-width) of approximately 35 nm or less, and the third zone 253 may include pores 263 having an average size or major dimensions (diameter, length-width) of approximately 30 nm or less. In some exemplary embodiments, pores 261 may be characterized as macropores, pores 262 within the intermediate region 952 may be characterized as mesopores, and pores 263 within the outer region 252 may be characterized as micropores.

[0063] In some embodiments, the main dimension D1 of the first zone 251 may be less than approximately 100 nm, the main dimension D2 may be less than approximately 150 nm, and the main dimension D3 of the third zone 253 may be approximately 200 nm. The relative dimensions, porosity, and electrical conductivity of the first zone 251, the second zone 252, and the third zone 253 may be adjusted to achieve a desired balance between minimizing the polysulfide shuttle effect and maximizing the specific capacity of the host battery. The first zone (inner core zone) 251 may have a carbon density of less than approximately 1 g / cc. The third zone (outer zone) 253, bounded by the surrounding or outer shell 255 of the particles 205, may have a carbon density of approximately 1 g / cc to less than 3.5 g / cc. The second zone (intermediate zone) 252 may have a carbon density of approximately 0.5 g / cc to 3 g / cc. Zones 251, 252, and 253 can each be characterized by the average pore size and average pore density associated with each region. The average pore size associated with each of zones 251-253 can decrease radially from the center of the porous primary carbon nanoparticles 205 to the outer porous shell 255.

[0064] Aggregates of porous primary carbon nanoparticles 105 and / or porous primary carbon nanoparticles 205 can be surface-etched using a method that includes CO2 etching to create pores on the outer surface of the aggregates and increase the surface area of ​​the carbon aggregates. After etching, the aggregates may contain three-dimensional graphene carbon ("3DG carbon"), which includes graphene layers interconnected as a three-dimensional ("3D") graphene structure. The resulting surface-etched aggregates of porous primary carbon nanoparticles 105 and / or porous primary carbon nanoparticles 205 have an I of approximately 0.95–1.05 D / I GThe aggregates may be characterized by a Raman spectroscopic signature having a ratio. In some embodiments, the aggregates may be produced by the thermal decomposition of hydrocarbon feedstock, as disclosed in jointly owned U.S. Patent No. 9,862,602, U.S. Patent No. 10,112,837, U.S. Patent No. 11,053,121, and / or U.S. Patent Application No. 2021 / 0292170, all of which are incorporated herein by reference.

[0065] Using the porous carbon aggregates described above, carbon-sulfur composite materials ("CSCs") can be produced by compounding the carbon aggregates with sulfur. In some examples, the sulfur-to-carbon weight ratio may be approximately 1:5 to 10:1. In some other examples, the sulfur-to-carbon weight ratio may be about 3. In some embodiments, a slurry containing the carbon-sulfur composite material and one or more polymer binders can be cast onto a suitable substrate as one or more layers or thin films of the carbon material to form a cathode in an exemplary Li-S battery. In some examples, the cathode substrate may include a cathode current collector. In some other examples, the cathode current collector may include aluminum. The carbon aggregates can withstand deformation under high shear mixing and thus can produce thin films or layers of carbon with desired porosity, thickness, and packing density. In some embodiments, the cathode has a packing density of at least about 7 mg / cm³ of carbon material (including sulfur, binder, and other components) on the substrate. 2 This can then be characterized by increasing the amount of sulfur coating at the cathode and decreasing the N / P ratio in the Li-S battery. In some embodiments, the porous carbon aggregates of porous carbon primary nanoparticles may include several layers of graphene ("FLG") nanoplatelets linked orthogonally to each other in a 3D porous graphene scaffold structure. These aggregates may also be included as three-dimensional graphene carbon ("3DG carbon").

[0066] Figure 3A shows schematic diagrams of mesoporous carbon nanoparticles 300A according to several embodiments. In some embodiments, the mesoporous carbon nanoparticles 300A may include interconnected bundles of conductive graphene layers arranged to form a 3D open porous scaffold structure. The nanoparticles 300A, and porous carbon aggregates containing the nanoparticles 300A, can be produced in an atmospheric microwave plasma reactor using high-throughput, low-cost decomposition of hydrocarbon gases such as natural gas. An exemplary microwave plasma reactor is disclosed in its entirety by reference in U.S. Patent No. 9,767,992, co-owned. For example, aggregates may be formed and grown in flight by adding additional carbon-based material derived from a carbon-containing gas entering the microwave plasma reaction chamber.

[0067] Carbon nanoparticles 300A may include three-dimensional ("3D") multimodal mesoporous carbon nanoparticles. As is generally understood and as referred to herein, mesoporous materials include materials containing pores having diameters of 2 nm to 50 nm, according to IUPAC nomenclature. For reference, IUPAC defines microporous materials as materials having pores with a diameter of less than 2 nm, and macroporous materials as materials having pores with a diameter of greater than 50 nm. In some examples, mesoporous carbon particles 300A may be characterized by a three-dimensional ("3D") hierarchical porous structure containing pores 380. In some embodiments, at least a portion of the hierarchical porous structure may further define a 3D open porous scaffold structure 381.

[0068] The nanoparticles 300A may comprise one or more interconnected bundles 382 of conductive graphene layers or sheets. Each interconnected bundle 382 may comprise one or more stacks 383 of graphene layers. Each stack 383 may comprise multiple graphene layers 386 stacked generally horizontally, as clearly shown by stack 384. One or more stacks 383 of graphene layers 386 may be arranged to form a 3D porous scaffold structure 381 containing mesopores. That is, multiple stacks 383 of conductive graphene layers 386 may be sintered together to define a 3D open porous scaffold structure 381 (containing mesopores 380 in the example of Figure 3A). In some embodiments, one or more of the stacks 383 may be connected substantially orthogonal to each other. The open porous scaffold structure 381 may be configured to provide electrical conduction between the contact points (not shown for simplicity) of the stacks of graphene layers 386. In some embodiments, each graphene layer 386 has a diameter or length dimension of approximately 50 nm to approximately 200 nm ("L"). a It can be characterized by the following. In some embodiments, the graphene stack 383 may include several layers of graphene ("FLG"), which may consist of 5 to 15 layers of graphene.

[0069] Multiple porous carbon primary nanoparticles 300A can be combined or linked to form a porous carbon aggregate of porous carbon primary nanoparticles. In this disclosure, three-dimensional graphene carbon ("3DG carbon") includes a porous carbon aggregate of mesoporous nanoparticles 300A. In some embodiments, the exemplary 3DG carbon described herein is approximately 50-300 m 2The 3DG carbon can be characterized by its Brunauer-Emmett-Teller ("BET") surface area, measured using nitrogen gas at a density of 1 / g. In some embodiments, 3DG carbon can be characterized by a graphene-to-amorphous carbon ratio of approximately 1% to 95%. In some embodiments, 3DG carbon can be characterized by a carbon purity of at least 99.9%. 3DG carbon can be characterized by an electrical conductivity of approximately 500 S / m to approximately 20,000 S / m when compressed at a pressure of approximately 12,000 pounds per square inch ("psi"). The open porous scaffold structure 381 can also provide a host scaffold-type structure for managing volume expansion resulting from the formation of long-chain polysulfides while trapping sulfur.

[0070] In some embodiments, sulfur may be trapped in the pores 380 of an open porous scaffold structure 381. In some embodiments, sulfur may also be trapped within a scaffold structure space 385 formed by orthogonally connected stacks 383 of graphene layers 384.

[0071] The porous carbon aggregates described herein and characterized using Raman spectroscopy exhibit a high degree of structural order and uniformity. As previously stated, “graphene” refers to an allotrope of carbon in the form of a two-dimensional atomic-scale hexagonal lattice, where one atom forms each vertex. The carbon atoms in graphene are sp 2 It can be a hybrid of carbon atoms. Furthermore, graphene is approximately 1580 cm³. -1 G-mode and approximately 1350cm -1 It has a Raman spectrum with two main peaks in the D mode (when using a 532 nm excitation laser). The porous carbon aggregate has an I of approximately 0.95 to approximately 1.05. D / I G It can be characterized by a Raman spectroscopic signature with a ratio.

[0072] In some embodiments, the aggregate 302 (see Figure 3B discussed below) may comprise multiple interconnected crimped 3D graphene sheets, multiple non-hollow carbonaceous spherical particles ("NHCS"), flat graphene, wrinkled graphene, or multiple carbon nanoonions ("CNO"). In some embodiments, the aggregate may comprise corrugated or flexible graphene platelets, which are similar to crepe paper and can be manufactured using a microwave process. The graphene platelets are sp 2 sp in graphene lattice structure 3 Because they can fuse together at mold defects, they can be flexible.

[0073] Figure 3B shows SEM micrographs 300B of porous carbon primary nanoparticle aggregates 302 according to several embodiments. In some embodiments, plasma-based processing conditions when applied or performed in a reactor, such as a microwave reactor, can be adjusted with a high degree of tunability to achieve high-density graphene-on-graphene and generate aggregates 302. The aggregates 302 can be surface-etched using methods including CO2 etching to create pores on the outer surface of the aggregates and increase the surface area of ​​the aggregates.

[0074] In some embodiments, aggregate 300B may combine with sulfur to form a carbon-sulfur composite material ("CSC"). A slurry containing the carbon-sulfur composite material may be cast onto a suitable substrate as one or more layers or thin films of carbon material to form a cathode in an exemplary Li-S battery. The cathode substrate may contain a cathode current collector such as aluminum. The aggregate may be characterized using Raman spectroscopy and may exhibit a high degree of order. Aggregate 300B has an I of approximately 0.95 to approximately 1.05 D / I G It can be characterized by a Raman spectroscopic signature with a ratio.

[0075] Figure 3C shows TEM micrographs 304 of porous carbon aggregates according to several embodiments. As shown in Figure 3C, the 3D few-layer graphene ("FLG") structure 304 is a porous carbon aggregate at a 50 nm scale. Those skilled in the art will understand that the micrographs are shown as examples only and other scales may exist without departing from the scope and spirit of this embodiment.

[0076] Any one of the Li-S battery cathode embodiments described herein may be configured or arranged for use in a cylindrical battery, a prism-shaped battery, a pouch cell, or any other suitable geometric shape. The Li-S cylindrical battery may conform to the dimensions of an 18650 battery (approximately 18 mm in diameter × approximately 65 mm in length), a 21700 battery (approximately 21 mm in diameter × approximately 70 mm in length), or a 4680 battery (approximately 46 mm in diameter × approximately 80 mm in length). In some embodiments, the Li-S battery may have a prism shape factor that can conform to the dimensions of a CP3553 battery. For example, an exemplary Li-S battery may have a height of approximately 56 mm to approximately 58 mm, a length of approximately 34 mm to approximately 36 mm, and a width of approximately 6 mm to approximately 8 mm.

[0077] Figure 4 shows a schematic diagram 400 illustrating an exemplary cylindrical battery 400 according to several embodiments. The battery 400 may include a shell 410 and a jelly roll 420. The shell 410 may have a longitudinal axis indicated as AA' in Figure 4, and the jelly roll 420 may be arranged along the longitudinal axis AA' within the shell 410. The jelly roll 420 may have a cross-section of a circle, rectangle, square, triangle, or any other geometric shape. The jelly roll 420 may include an anode 422, a first barrier layer (or separator layer) 424, a cathode 426, and a second barrier layer 428, each in the form of a rollable sheet. The anode 422, the first barrier layer 424, the cathode 426, and the second barrier layer 428 may be laminated on top of each other. Therefore, the anode 422 and cathode 426 may be separated by a first barrier layer and a second barrier layer to avoid undesirable short circuits within the battery 400. In some other embodiments, a center pin or spindle (not shown in Figure 4 for simplicity) may be attached to the inner edge of the anode 422, and the cathode-first barrier layer-anode-second barrier layer lamination may be wound or wrapped radially around the center pin to form a jelly roll 420. The anode current collector 402 (if the anode is not a self-supporting anode) and the cathode current collector 404 may be integrated into the anode layer and the cathode layer, respectively.

[0078] In some embodiments, the anode 422, the first barrier layer 424, the cathode 426, and the second barrier layer 428 may share the same dimensions, and the sheets may be aligned with each other during the winding process, resulting in no sheets protruding from the jelly roll 420. Either the anode 422 or the cathode 426 current collector may include a current collector tab, which may protrude after the sheet has been wound onto the jelly roll 420. The tab 423 may connect the anode 422 or the cathode 426 to a negative or positive terminal (not shown in Figure 4 for simplicity) via any preferred process, including a mechanical welding process. In some embodiments, the tab 423 may be a cathode current collector tab. The anode current collector (not shown for simplicity) may be located at the outer edge of the jelly roll 420, and the cathode current collector tab 423 may be located approximately in the center of the jelly roll 420.

[0079] In some embodiments, either electrode (e.g., anode 422 or cathode 426) may be positioned offset from the other electrodes, as well as the first and second barrier layers 424 and 428, during the winding process, so that the portion 425 may protrude outward from the jelly roll 420. In some embodiments, an electronically conductive adhesive (not shown in Figure 4 for simplicity) may be disposed within the shell 410 at the top and bottom of the shell 410. The protruding portion 425 may be connected to the negative or positive terminal of the shell 410 via the electronically conductive adhesive, thereby eliminating the need for a mechanical welding process. In some embodiments, the anode 422, anode current collector (not shown), first barrier layer 424, cathode 426, cathode current collector 404, and second barrier layer 428 may be laminated on top of each other. A center pin or spindle (not shown in Figure 4 for simplification) may be configured as a cathode terminal and may be attached to the cathode current collector 404. When arranged as a jelly roll, the anode current collector may be located on the outer edge of the jelly roll 420, and the cathode current collector 404 may be located approximately in the center of the jelly roll 420.

[0080] In various embodiments, the anode 422 may be any suitable material typically used as an anode in a Li-S battery. For example, the anode 422 may be lithium foil or a lithium substrate. In some examples, the anode 422 may include a current collector for supporting the lithium foil or lithium substrate. In some embodiments, the anode 422 may include a self-supporting Li alloy anode.

[0081] In some embodiments, the cathode 426 may comprise one or more layers of a thin film or CSC containing any of the aforementioned porous carbon aggregates containing metal nanoparticles. The cathode 426 may be disposed on a cathode current collector 404. The cathode film may coat both sides of a current collector, such as aluminum foil, to provide maximum cathode capacity. The cathode CSC, comprising porous carbon aggregates with metal nanoparticles, may contain micro-trapped sulfur from multiple pores as the cathode electroactive material. The electroactive material (sulfur) may constitute approximately 60% to 90% by weight of the cathode film. The electroactive material of cathode 426 may comprise other suitable sulfur-containing materials, such as lithium sulfide.

[0082] The battery 400 may include an electrolyte (not shown in Figure 4 for simplicity) incorporated into the jelly roll 420. In some embodiments, the battery 400 may have a liquid electrolyte, which can be added to the shell 410 after the jelly roll 420 has been placed inside the shell or casing 410. In some other embodiments, the battery 400 may include a non-aqueous electrolyte, such as a solid electrolyte, gel electrolyte, or polymer film electrolyte, incorporated into the jelly roll 420. For example, between a first barrier layer 424 and a second barrier layer 428, one barrier layer may function as a separator and the other barrier layer may function as a non-aqueous electrolyte film. In some other embodiments, each of the first barrier layer 424 and the second barrier layer 428 may function as both a separator and a non-aqueous electrolyte film. The electrolyte may include any one of the electrolyte compositions described herein.

[0083] In some embodiments, a microporous monolayer polypropylene film may be used as a separator disposed between the anode 422 and the cathode 426. An example separator (e.g., Celgard) R The porosity of 2500) can be approximately 55%. The separator may have ionic conductivity similar to the electrolyte but may help reduce the formation of lithium dendritic crystals. The separator may be formed from a ceramic-containing material that does not chemically react with metallic lithium. As a result, a separator having a ceramic-containing material can be used to control lithium ion transport through pores dispersed across the separator while simultaneously preventing short circuits by obstructing the flow or passage of electrons through the electrolyte. The separator layer may include a mechanical strength enhancer coated and / or deposited on the anode. The mechanical strength enhancer may provide structural support for the battery, prevent the formation of lithium dendritic crystals from the anode, and / or prevent the protrusion of lithium dendritic crystals throughout the battery. In some typical embodiments, ceramic particles may be impregnated within a microporous monolayer polypropylene film. In some typical embodiments, the separator may include a ceramic-coated separator.

[0084] In cylindrical lithium-ion batteries, the high-density packing of various layers within the jelly roll 420, and the volume changes during charge-discharge cycles, can cause mechanical stress and aging of the battery 400. Volume changes can result from heterogeneous lithium plating and dendritic crystal formation at the anode, polysulfide "shuttle effect," and growth at the solid electrolyte interface. Dendritic crystals can even cause fires due to localized heating. Furthermore, pit formation on the anode 422 leads to heterogeneous transport of Li ions from the anode 422 to the cathode 426 and damage to protective coatings / layers placed on the anode. Similarly, during charging cycles, lithium dendritic crystals can form on the metal anode due to heterogeneous transport and deposition of Li ions from the cathode to the anode. Pit formation and / or dendritic crystal formation result in non-uniform stress and volume expansion of the jelly roll 420, which, over time, causes the layers of the roll 420 to lose close contact with each other, exacerbating these problems and accelerating degradation / capacity reduction. A cathode comprising one of the aforementioned CSC materials containing any of the aforementioned porous carbon aggregates, a self-supporting anode comprising one of the aforementioned Li-Mg alloy compositions, and one of the aforementioned electrolyte compositions may mitigate the effects of the polysulfide shuttle effect and mechanical stress, thereby increasing the cycle life of the Li-S battery.

[0085] Figure 5A shows a schematic diagram of a lithium-sulfur battery anode 500A, including one or more protective layers disposed on top of the anode active material layer, according to several embodiments. An exemplary anode 500A may include an anode active material layer 503A, which may include any of the self-supporting lithium alloy anode compositions described herein. In some embodiments, the anode active material layer 503A may include a 90Li-Mg alloy. In some embodiments, the anode active material layer 503A may also include a self-supporting lithium metal. In some embodiments, the anode 500A may include a reacted alloy layer 504A disposed on top of the anode active material layer 503A. In some embodiments, the reacted alloy layer 504A may be formed in situ by rolling the anode active material layer (also referred to herein as anode active material foil) 503A in a rolling mill with an alloyed metal layer or foil that reacts with the anode active material layer 503A during the rolling process. That is, the reacted alloy layer 504A can be disposed as a surface layer on the anode active material layer 503A. In some embodiments, the alloyed metal layer or foil may contain one or more of tin, indium, gallium, or aluminum. Thus, in some embodiments, the reacted alloy layer 504A may contain Li of a common composition. x Sn y Li x In y Li x Ga y , or Li x Al y It may contain one or more alloys having [a specific characteristic]. In some embodiments, the thickness of the reacted alloy layer 504A may be less than 1 μm.

[0086] Since the reacted alloy layer 504A can be electronically conductive, during the lithium-sulfur cycle, lithium will be plated onto the reacted alloy layer 504A, and the reacted alloy layer may help uniform lithium nucleation and prevent the formation of dendritic crystals. To control plating and peeling, an ion-conductive protective polymer coating 505A may be disposed on the reacted alloy layer 504A. The protective polymer coating 505A may also help to block polysulfide from reaching the anode active material layer 503A. Thus, the reacted alloy layer 504A may be disposed between the anode active material layer 503A and the protective polymer coating 505A. In some embodiments, the protective polymer coating 505A may include polyvinylidene fluoride ("PVDF"). In some embodiments, the protective polymer coating 505A may include one or more of pentaerythritol tetraacrylate ("PETEA") or polyethylene glycol dimethacrylate ("PEGDMA"). In some embodiments, the thickness of the protective polymer coating 505A may be less than 1 μm. In some embodiments, the thickness of the protective polymer coating 505A may be about 1 μm to about 10 μm.

[0087] Figure 5B shows a schematic diagram of a lithium-sulfur pouch cell anode 500B including one or more protective layers according to several embodiments. As can be seen in the figure, the anode 500B may include an anode active material layer 503B and a protective layer comprising a reacted alloy layer and a protective polymer coating disposed on each surface 506B and 506B' of the anode active material layer 503B. Specifically, the reacted alloy layer 504B may be disposed between the surface 506B of the anode active material 503B and the protective polymer coating 505B. In addition, the reacted alloy layer 504B may be disposed between the surface 506B' of the anode active material 503B and the protective polymer coating 505B'.

[0088] Referring to Figure 5B, the reacted alloy layers 504B and 504B' disposed on each surface of the anode active material layer 503B can be formed in situ by rolling the anode active material layer or foil 503B sandwiched between alloyed metal layers or foils. The foil of the alloyed metal layer may react with the anode layer 503A during the rolling process to form reacted alloy layers on each surface of the anode layer 503B, as described below with reference to Figure 6A. In some embodiments, the alloyed metal layer or foil may contain one or more of tin, indium, gallium, or aluminum. Thus, in some embodiments, the reacted alloy layers 504B and 504B' may contain Li of a common composition. x Sn y Li x In y Li x Ga y , or Li x Al y It may contain one or more alloys having the following properties. In some embodiments, the thickness of the reacted alloy layers 504B and 504B' may be less than 1 μm.

[0089] Referring again to Figure 5B, the protective polymer coatings 505B and 505B' disposed on the reacted alloy layers 504B and 504B', respectively, may contain polyvinylidene fluoride ("PVDF"). In some embodiments, the protective polymer coatings 505B and 505B' may contain one or more of pentaerythritol tetraacrylate ("PETEA") or polyethylene glycol dimethacrylate ("PEGDMA"). In some embodiments, the thickness of each of the protective polymer coatings 505B and 505B' may be less than 1 μm. In some embodiments, the thickness of each of the protective polymer coatings 505B and 505B' may be about 1 μm to about 10 μm.

[0090] Figure 6A shows a schematic diagram of an exemplary roll-to-roll continuous method 600A for forming a lithium anode active material layer sandwiched between reacted alloy layers, according to several embodiments. Exemplary operation 600A may begin in 606A by providing an anode active material layer 603A disposed on a first alloyed metal layer or foil 602A'. The anode active material layer 603A may comprise a foil or multiple foils of lithium metal containing any one of the lithium alloy compositions previously disclosed herein. The foil 603A disposed on 602A' may be supported using one or more feed rolls (not shown for simplification). Operation 600A may continue in 607A by providing a second alloyed metal layer or foil 602A which may be supported using one or more feed rolls (not shown for simplification). In 608A, the operation can be carried out continuously through one or more rolling mills, with the anode active material layer 603A positioned on the first alloying metal layer 602A' and the second alloying metal layer 602A, so that the anode layer 603A is sandwiched between the first alloying metal layer 602A and the second alloying metal layer 602A', respectively. Those skilled in the art will understand that the operation of arranging and feeding various layers to one or more rolling mills is shown only as an example, and other options for arranging and feeding one or more layers for rolling mills may exist without departing from the scope and spirit of this embodiment.

[0091] Referring to Figure 6A, the rolling mill generally includes a pair of rolls 601A and 601A', which are configured to apply a predetermined pressure to compress and sandwich the anode active material layer 603A between the alloyed metal layers 602A and 602A'. The rolls 601A and 601A' may be heated. Not constrained by any particular theory, when exposed to high temperature and pressure during rolling, operation 600A may, in 609A, terminate the formation of reacted alloy layers 604A and 604A' on each surface of the anode active material layer 603A by reacting the alloyed metal layers 602A and 602A' with each surface of the anode active material layer 603A. That is, exemplary operation 600A may terminate the formation of the anode active material layer 603A sandwiched between the reacted alloy layers 604A and 604A' as the layer passes through one or more rolling mills in a single pass mode.

[0092] As previously stated herein, the alloyed metal layer or lithium alloy foil may contain one or more of tin, indium, gallium, or aluminum. Therefore, in some embodiments, the reacted alloy layers 604A and 604A' are Li of a common composition. x Sn y Li x In y Li x Ga y , or Li x Al y It may contain one or more alloys having the following properties. In some embodiments, the thickness of the reacted alloy layers 604A and 604A' may be less than 1 μm. In some embodiments, the thickness of the anode active material layer may be at least 50 μm. Thus, the reacted alloy layers may be considered as surface layers disposed on each surface of the anode active material layer 603A. Those skilled in the art will understand that the various layer thicknesses shown in Figure 6A are shown as examples for illustrative purposes only, and other scales may exist without departing from the scope and spirit of this embodiment.

[0093] In some embodiments, submicron-thick reacted alloy layers 604A and 604A' can be formed by varying one or more of the following: the thickness of the alloyed metal layers 602A and 602A', the temperature of the rolls 601A and 601A', the rolling mill pressure, or the rate at which the layers pass through the rolling mill (or line speed). Thus, in the exemplary roll-to-roll ("R2R") method 600A, the alloyed metal may not penetrate the anode active material layer 603A but instead form an interconnected three-dimensional lithium metal / lithium metal alloy integrated network. Instead, the reacted alloy layers 604 and 604A' are disposed as thin surface layers on the anode active material layer 603A. In some embodiments, the disadvantages in specific energy ("Wh / kg") and energy density ("Wh / L") caused by the addition of the reacted alloy layers may be less than 1%.

[0094] In some embodiments, a protective polymer coating may be disposed on each of the reacted alloy layers 604A and 604A' to add an additional protective layer to the anode active material layer 603A. As previously stated, the protective polymer coating may comprise one or more of polyvinylidene fluoride ("PVDF"), pentaerythritol tetraacrylate ("PETEA"), or polyethylene glycol dimethacrylate ("PEGDMA"). In some embodiments, the thickness of the protective polymer coating disposed on each reacted alloy layer may be less than 1 μm. In some embodiments, the thickness of the protective polymer coating disposed on each reacted alloy layer 604 and 604' may be about 1 μm to about 10 μm. In some embodiments, the protective polymer coatings 505B and 505B' (see Figure 5B) may be applied using any preferred method, including spray coating or Micro-Gravure® coating.

[0095] In some embodiments, the exemplary reacted alloy layer described above, as a protective layer within a self-supporting anode, may also protect a lithium metal anode or lithium alloy anode supported on a current collector. The exemplary anode current collector may include copper. Figure 6B shows a schematic diagram of an exemplary roll-to-roll continuous method 600B for forming a reacted alloy layer on an anode supported on a current collector, according to some embodiments. Exemplary operation 600B may begin in 606B by providing a first anode active material layer 603B disposed on a first current collector 605B. The operation may continue in 607B by providing a second anode layer 603B' disposed on a second current collector 605B', and in 608B by providing an alloyed metal layer or foil 602B. Each of these layers may be supported using one or more feed rolls (not shown for simplicity). The first anode active material layer 603B and the second anode active material layer 603B' may comprise a lithium foil or a plurality of foils or layers comprising any one of the lithium alloy compositions previously disclosed herein.

[0096] Referring to Figure 6B, the operation may continue in 609B to continuously feed a first anode active material layer 603B supported on a current collector 605B, a second anode active material layer 603B supported on a current collector 605B', and an alloyed metal layer or foil 602B through one or more rolling mills. As previously stated, the rolling mill may generally include a pair of rolls 601B and 601B', which may be configured to apply a predetermined pressure to compress and facilitate the alloyed metal layer 602B so that it comes into contact with each of the first anode active material layer 603B and the second anode active material layer 603B' as it passes through the rolls. In some embodiments, one or more of the rolls 601B and 601B' may be heated. The operation may be completed in 610B when the alloyed metal layer 602B reacts with the first anode active material layer 603B and the second anode active material layer 603B' during rolling, forming the reacted alloy layers 604B and 604B' on the exposed surfaces of each anode active material layer 603B and 603B' respectively (i.e., on the surface of the anode active material layer that is not in contact with the current collector).

[0097] In some embodiments, the thickness of the reacted alloy layers 604B and 604B' may be less than 1 μm. In some embodiments, the thickness of the anode active material layer may be at least 50 μm. Thus, the reacted alloy layers 604A and 604B can be considered surface layers disposed on the surfaces of each anode layer 603B and 603B' that are not in contact with their respective current collectors. Those skilled in the art will understand that the various layer thicknesses shown in Figure 6B are shown as examples for illustrative purposes only, and other scales may exist without departing from the scope and spirit of this embodiment. Furthermore, those skilled in the art will understand that the operation of arranging and feeding the various layers into one or more rolling mills is shown as an example only, and other options may exist without departing from the scope and spirit of this embodiment.

[0098] In some embodiments, a protective polymer coating may be disposed on each of the reacted alloy layers 604B and 604B' to add an additional protective layer to each of the anode active material layers 603B and 603B'. As previously stated, the protective polymer coating may comprise one or more of polyvinylidene fluoride ("PVDF"), pentaerythritol tetraacrylate ("PETEA"), or polyethylene glycol dimethacrylate ("PEGDMA"). In some embodiments, the thickness of the protective polymer coating disposed on each reacted alloy layer may be less than 1 μm. In some embodiments, the thickness of the protective polymer coating disposed on each reacted alloy layer may be about 1 μm to about 10 μm.

[0099] As mentioned above, lithium-sulfur batteries may contain an electrolyte characterized by a high solvation electrolyte, i.e., a high lithium polysulfide solubility. In some examples, the exemplary electrolyte may contain 1M lithium bis(trifluoromethanesulfonyl) ("LiTFSI") in a 1,2-dimethoxyethane ("DME")-1,3-dioxolane ("DOL") solvent mixture containing a lithium nitrate (LiNO3) additive. DME is reactive with lithium, and during the course of cycling, lithium alkoxy species may be formed, which tend to reduce both Coulomb efficiency and cycle life. The reaction between DME and lithium may contribute to the continuous formation of a solid electrolyte interphase ("SEI") that consumes both the electrolyte and lithium metal. Thus, lithium-sulfur cells may fail due to high impedance when either of these components (electrolyte or lithium) is depleted.

[0100] In contrast to DME, ionic liquids can be characterized by their very low reactivity with lithium metal. Furthermore, the relatively low solubility of polysulfides in ionic liquids can mitigate anodic corrosion by polysulfides and, therefore, reduce the polysulfide "shuttle effect." However, this low lithium-ion conductivity in lithium-sulfur batteries containing ionic liquid electrolytes can result in relatively low discharge capacity and relatively high impedance. Therefore, a balance is needed between cycle life and discharge capacity.

[0101] In some embodiments, exemplary lithium-sulfur batteries may include a highly solvating liquid fluorinated ether electrolyte to increase the battery's discharge capacity without reducing anode stability. Anode stability can be improved by coating the anode (e.g., a lithium-magnesium alloy anode) with a polymer matrix that confines the ionic liquid. Exemplary anode protective coatings can prevent the fluorinated ether electrolyte from coming into contact with the anode.

[0102] Therefore, in some embodiments, the anode protective coating for lithium-sulfur battery anodes may include an ionic liquid confined within a polymer matrix. Without being constrained by any particular theory, the ionic liquid confined within the polymer matrix is ​​high Li + To promote ionic conductivity and achieve a substantially uniform anode protective coating, it may be possible to increase the thickness of the film or coating. That is, the anode coating does not need to be thin (less than about 1 micron) to compensate for the low ionic conductivity of the polymer matrix layer without trapped ionic liquid. Thin anode coatings are prone to cracking over battery cycles. Furthermore, the ionic liquid can form a stable SEI and prevent polysulfide formation.

[0103] In some embodiments, the ionic liquid confined within the polymer matrix may contain lithium salts to improve the lithium ion conductivity of the anode protective coating. In some examples, exemplary lithium salts may include bis(fluorosulfonyl)imide lithium ("LiFSI") or bis(trifluoromethanesulfonyl)imide lithium ("LiTFSI"). These salts may also form stable SEIs on the anode surface during battery formation. In some other examples, the ionic liquid may contain bis(trifluoromethanesulfonyl)imide sodium ("NaTFSI"), which may enhance SEI formation to improve the diffusion rate of lithium ions through the anode protective coating. In some other examples, the ionic liquid may contain LiNO3 to form an SEI and prevent polysulfides from reaching the anode.

[0104] In some examples, the exemplary anode protective coating may be in the form of a solid layer or a gel and may contain an ionic liquid trapped between the polymer layer and / or other similar porous material.

[0105] In some embodiments, a method for forming an anode protective coating containing an ionic liquid trapped within a polymer matrix may include: preparing a coating solution by mixing a precursor containing one or more monomers or oligomers, an ionic liquid, one or more lithium salts, and a polymerization initiator (e.g., a UV or thermal initiator) in a solvent; applying the coating solution to an anode; initiating polymerization of one or more monomers or oligomers; removing the solvent by drying; and curing the coating to form a polymer matrix implanted with the ionic liquid.

[0106] In some embodiments, the amount of precursor (also referred to herein as “solids”) in the anode protective coating solution may be about 3% to about 30% by weight. The solids may be calculated as the difference between the total weight of the ionic liquid (including the precursor) and the weight of the solvent, and may be expressed as a percentage of the total weight of the ionic liquid including other precursors. Table 1 provides a list of exemplary components in the anode protective coating solution according to some embodiments. Dimethyl ether (“DME”) may be used as a solvent. [Table 1]

[0107] Therefore, an anode protective coating containing a polymer matrix with a confined ionic liquid can be formed by applying a coating solution having one or more precursors or components, as shown in Table 1. The respective roles of each precursor in an exemplary anode protective coating are also shown in Table 1. Polymerization can be initiated by UV light or by heating. The anode protective coating can be dried and cured to form a uniform coating on the anode associated with a lithium-sulfur battery.

[0108] In some embodiments, the exemplary photoinitiator may include 2-hydroxy-2-methyl-1-phenylpropanone ("HMPP") for ultraviolet (UV) curing. In some other embodiments, 2,2'-azobis(2-methylpropionitrile) ("AIBN") may be used as an initiator during thermal curing.

[0109] Without being bound by the author's specific theory, the ionic conductivity (σ, mS / cm) in an electrolyte mixture can be expressed by equation (2), as shown below.

number

[0110] In some embodiments, it is possible to increase ion mobility (μ) and the number density (n) of free charged species by confining an ionic liquid containing anions and cations within a polymer matrix, while providing a solid or gel anode protective coating that inhibits contact between the highly solvated electrolyte and the lithium anode in a lithium-sulfur battery.

[0111] In some embodiments, the exemplary polymer matrix in the anode protective coating may contain one or more acrylate groups or ethylene oxide groups. In some examples, the ethylene oxide groups may dissociate one or more lithium salts contained in the exemplary anode protective coating, improving the number density (n) of free-charged species. However, high concentrations of Li salts may form clusters that result in low ion mobility (μ).

[0112] In some embodiments, the polymer matrix in the anode protective coating may comprise one or more monomers or oligomers. In some examples, one or more monomers or oligomers may comprise one or more of polyethylene glycol dimethacrylate ("PEGDMA"), pentaerythritol tetraacrylate ("PETEA"), polymethyl methacrylate ("PMMA"), polyethylene oxide ("PEO"), polyethylene glycol diacrylate ("PEGDA"), the crosslinked polymer pentaerythritol tetraacrylate-polyethylene glycol dimethacrylate ("PETEA-PEGDMA"), the crosslinked polymer poly(vinylidene fluoride-hexafluoropropylene copolymer) ("PVDF-HFP"), or other similar monomers or oligomers, or combinations thereof.

[0113] In some embodiments, exemplary cations associated with anionic liquids trapped within the polymer matrix of the anode protective coating are 1-ethyl-3-methylimidazolium ("Emim"), 1-butyl-3-methylimidazolium ("Bmim"), and N-propyl-N-methylpyrrolidinium ("Pyr"). 13 "), 1-butyl-1-methylpyrrolidinium ("Pyr 14 」 ), 1-methyl-1-(2-methoxyethyl)pyrrolidinium ("Pyr 1201 」 ), N-methyl-N-propylpiperidinium bis(trifluoromethanesulfonyl)imide ("PP 13 TFSI), or 1-butyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide ("PP 14 It may contain one or more of the following cations (TFSI), or other similar cations.

[0114] In some embodiments, the exemplary anions associated with the ionic liquid trapped within the polymer matrix of the anode protective coating may include one or more of bis(fluorosulfonyl)imide ("FSI"), bis(trifluoromethanesulfonyl)imide ("TFSI"), or dicyanamide ("DCA").

[0115] In some embodiments, the exemplary ionic liquids confined within the polymer matrix of the anode protective coating are 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide ("EmimFSI"), N-propyl-N-methylpyrrolidinium bis(fluorosulfonyl)imide ("Pyr"), and others. 13 FSI"), N-propyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide ("Pyr 13 TFSI"), 1-butyl-1-methylpyrrolidinium bis(fluorosul)imide ("Pyr 14 FSI"), 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide ("Pyr 14 TFSI ("Emim DCA"), 1-ethyl-3-methylimidazolium disinamide ("Emim DCA"), or 1-methyl-1-(2-methoxyethyl)pyrrolidinium bis(trifluoromethanesulfonyl)imide ("Pyr"). 1201 It may include one or more of the following:

[0116] In some embodiments, the exemplary anode protective coating may include salts comprising bis(trifluoromethanesulfonyl)imide lithium ("LiTFSI"), bis(fluorosulfonyl)imide lithium ("LiFSI"), bis(fluorosulfonyl)imide sodium ("NaFSI"), bis(trifluoromethanesulfonyl)imide sodium ("NaTFSI"), or lithium nitrate ("LiNO3").

[0117] In some embodiments, the thickness of an exemplary polymer matrix having an ionic liquid trapped within and after curing may be less than about 10 μm. In some other embodiments, the amount of ionic liquid trapped in the polymer matrix may be about 10% to about 40% by weight. In some embodiments, the coating amount of the polymer matrix having an ionic liquid trapped on the anode of a lithium-sulfur battery is about 10 μg / cm³. 2 ~about 600μg / cm 2 This is possible. In some other embodiments, the amount of precursor (also referred to herein as “solids”) in the exemplary anode coating solution may be about 3% to about 30% by weight. As previously stated, the solids may be calculated as the difference between the total weight of the ionic liquid (including other precursors) and the weight of the solvent, and may be expressed as a fraction of the total weight of the ionic liquid including other precursors.

[0118] In some embodiments, a lithium-sulfur battery may include a lithium alloy anode, an anode protective coating disposed on the anode, a cathode, and a liquid fluorinated electrolyte. In some examples, the anode protective coating may include a polymer matrix and an ionic liquid confined within the polymer matrix, and any one of the anode protective coatings described herein may be disclosed. In some examples, the liquid fluorinated electrolyte may include one or more of lithium nitrate (LiNO3) or lithium bis(trifluoromethanesulfonyl)imide ("LiTFSI").

[0119] An exemplary anode may include any one of the anodes described herein. In some examples, the exemplary anode may be a freestanding anode. In some other examples, the exemplary anode may be supported on an anode substrate or a current collector. An exemplary cathode may include any one of the cathodes described herein. [Examples]

[0120] In the embodiments described below, the electrolyte used in the Li-S battery embodiments comprises approximately 50:25:25 (vol%) DME:DOL:BTFE, approximately 0.4 M LiTFSI, and approximately 2 wt% LiNO3. For symmetrical half-cell Li-S battery tests, the exemplary electrolyte may include approximately 1 M lithium polysulfide, Li2S6.

[0121] Example 1. Cycle performance data of a self-supporting 90Li-Mg alloy anode in a half-type or symmetrical Li cell. Figure 7 illustrates plots illustrating cycle performance data for self-supporting anodes containing Li-Mg alloy in half-type or symmetrical lithium-sulfur battery cells in several embodiments. In particular, Figure 7 provides a comparison of the cycle performance of self-supporting 90Li-Mg alloy anodes and self-supporting Li metal anodes (100 wt% Li anode) in half-type or symmetrical Li cells. Referring to Figure 7, half-type cell tests demonstrate that cells containing exemplary 90Li-Mg alloy anodes and the electrolytes described above improve cycle life performance compared to cells containing Li metal anodes with the same electrolyte. After approximately 300 cycles, half-type cells with Li metal anodes showed increased polarization (overpotential of approximately 100 mV), whereas half-type cells with 90Li-Mg alloy anodes maintained low polarization for approximately 400 hours, demonstrating the superior cycle performance of self-supporting 90Li-Mg alloy anodes, even in the presence of polysulfides in the electrolyte.

[0122] Example 2A. Formation cycle data for self-supporting 90Li-Mg alloy anodes and Li metal anodes in exemplary Li-S coin cells at a C / 20 charge / discharge rate. Figures 8A–8C illustrate the formation cycle data for self-supporting anodes containing a Li-Mg alloy in exemplary lithium-sulfur coin cells in several embodiments. Cycle data were collected using coin cells containing self-supporting 90Li-Mg alloy anodes and Li metal anodes at a C / 20 charge / discharge rate. The formation (activation) cycle consisted of two cycles at a C / 20 rate. Battery formation involves the process of performing initial charge / discharge operations on newly assembled battery cells. Coin cells containing self-supporting 90Li-Mg alloy anodes exhibited a low discharge capacity of approximately 700 mAh / g during the first cycle.

[0123] Referring to Figure 8A, a small but significant inflection in potential can be observed towards the end of the discharge, which may indicate a slow reaction rate from surface reactions or bulk diffusion to the surface. However, after activation during the first discharge, the capacity of the cell with the 90Li-Mg alloy anode improved during the second cycle, becoming comparable to that of the coin cell with the Li metal anode. Overpotential during the charging cycle was found to be low with the self-supporting 90Li-Mg alloy anode, which may suggest easy nucleation and Li plating on the 90Li-Mg alloy, due to the potential relaxation of dendritic crystal formation at the 90Li-Mg anode compared to the Li metal anode.

[0124] Example 2B. Estimated residual discharge capacity versus lithium content in a self-contained Li-Mg anode after a single discharge in an exemplary lithium-sulfur battery with different initial anode thicknesses. Figure 8D illustrates plots illustrating the estimation of discharge capacity as a function of the lithium content remaining in the self-supporting anode containing a Li-Mg alloy after a single discharge of a lithium-sulfur battery in several embodiments. Referring to Figure 8D, at least about 4 mAh / cm² 2With a nominal capacity, a self-supporting 90Li-Mg alloy anode with a thickness exceeding approximately 20 μm can retain a single-phase solid solution of Li-Mg alloy BCC during battery cycling. However, a self-supporting 90Li-Mg alloy with a thickness of at least 100 μm may be required to maintain a lithium content of approximately 70% to 90% by weight of the initial lithium content in the anode during cycle battery operation.

[0125] Example 3. Discharge capacity and capacity retention of an exemplary Li-S coin cell having a self-supporting 90 Li-Mg alloy anode and a Li metal anode at an E / S of approximately 5 and a C / 3 rate. Figures 9A-9B illustrate the cathode discharge capacity and capacity retention of exemplary Li-S coin cells, including a self-supporting anode containing a Li-Mg alloy, in several embodiments. The thickness of the self-supporting 90Li-Mg alloy anode was approximately 100 μm. The thickness of the self-supporting Li metal anode was approximately 80 μm. A Celgard 2500 separator was used between the cathode and anode. The cathode coating amount was approximately 7.3 mg / cm². 2 ~Approximately 7.4 mg / cm³ 2 The nominal capacity was approximately 4 mAh / cm³, based on the amount of cathode active material. 2 The N / P ratio was approximately 2. Referring to Figures 9A-9B, an improvement of approximately 50% in cycle life was observed with the Li metal anode, accompanied by an increase in the average number of cycles (approximately 141 cycles), compared to approximately 210 cycles with the 90Li alloy anode. Furthermore, even after approximately 140 cycles, the capacity degradation down to 80% capacity was more gradual with the 90Li-Mg alloy anode, whereas the capacity degradation was more rapid with the Li metal anode. Without being constrained by any particular theory, when used with a fluorinated ether electrolyte, Li-S batteries containing a 90Li-Mg alloy anode can improve battery cycle life by at least 50%.

[0126] Example 4. Li-S coin cell performance at various Mg concentrations in a self-supporting Li-Mg alloy anode, with respect to cycle stability, initial capacity, and activation time at an E / S and C / 3 rate of approximately 5. Figures 10A-10B illustrate the performance of Li-S coin cells at various magnesium concentrations in a self-supporting anode containing a Li-Mg alloy in several embodiments. The effects of various Mg concentrations on cycle stability, initial capacity, and activation time in cells with a self-supporting Li-Mg alloy anode were investigated at an E / S and C / 3 rate of approximately 5. The thickness of the Li-Mg alloy anode was approximately 100 μm. The cathode coating amount was approximately 7.2 mg / cm². 2 Therefore, the cathode capacity in each case is approximately 4 mAh / cm². 2 A Celgard 2500 separator was used between the cathode and anode. Referring to Figures 10A-10B, increasing the magnesium content to 28 wt% reduced the initial discharge capacity and increased the battery activation time. The 72Li-Mg alloy (28 wt% Mg) required a long activation period, based on the number of cycles (approximately 100 cycles) required to reach an initial discharge capacity of approximately 500 mAh / g. For clarity, the 72Li-Mg alloy contains approximately 90 wt% Li and approximately 10 wt% Mg. Reducing the magnesium content to 3.4 wt% reduced cycle stability.

[0127] Without being constrained by any particular theory, a Li-S battery having a self-contained 90Li-Mg alloy with an electrolyte of DME:DOL:BTFE in a 50:25:25 (vol%) ratio, containing approximately 0.4M LiTFSI and approximately 2 wt% LiNO3, may offer a good compromise between cycle stability, initial maximum capacity, discharge capacity, capacity retention, and battery activation time at E / S of 5 or less. Increasing the Mg content in the Li-Mg alloy anode beyond approximately 10 wt% may result in an undesirably slow activation of the Li-S battery to achieve the target battery capacity (mAh / g).

[0128] Example 5. Cathode discharge capacity and capacity retention of a lithium-sulfur coin cell having a self-supporting 90Li-Mg alloy anode at an E / S of about 4 and a C / 3 rate. Figures 11A-11B show plots 1100A-1100B illustrating the cathode discharge capacity and capacity retention of a self-supporting lithium-sulfur coin cell anode containing a Li-Mg alloy, according to some embodiments. Tests were conducted using a self-supporting 90Li-Mg alloy at an E / S of about 4 and a C / 3 rate (charge and discharge). An exemplary 90Li-Mg alloy anode having a thickness of about 100 μm and a Li metal anode having a thickness of about 80 μm were used. The cathode coating amount was approximately 7.6 mg / cm 2 It was. The cathode capacity in each case was approximately 4 mAh / cm 2 It was. A Celgard 2500 separator was used between the cathode and the anode.

[0129] Referring to Figures 11A-11B, a Li-S discharge capacity of at least 400 mAh / g was measured at 80% capacity through about 175 cycles even at an E / S of about 4. Capacity retention was found to be stable with respect to cycle operation even at a low E / S of about 4. Along with an increase in the average number of cycles (88 cycles) with a Li metal anode, an improvement of about 95% in cycle life up to about 172 cycles with a 90Li-Mg alloy anode was observed. Without being bound by a particular theory, a Li-S battery having a self-supporting 90Li-Mg alloy with an electrolyte of about 0.4 M LiTFSI and about 2 wt% LiNO3 and 50:25:25 (vol%) DME:DOL:BTFE can provide a good compromise between cycle stability, initial maximum capacity, cathode discharge capacity, capacity retention, and battery activation time at an E / S ratio of about 4. At an E / S ratio of about 3, a Li-S coin cell having both 90Li-Mg allows both the anode and the Li-metal anode to not be fully implemented.

[0130] Example 6. Scanning electron microscope ("SEM") micrographs of the surfaces of a self-supporting 90Li-Mg alloy anode (bottom) and a Li-metal anode (top) from a Li-S coin cell after the first discharge. Figure 12A shows SEM micrographs of the surface of a self-supporting 90Li-Mg alloy anodes taken from lithium-sulfur coin cells after the initial discharge, according to several embodiments. Referring to Figure 12A, the 90Li-Mg alloy anodes taken from the cells after the initial discharge showed a smoother surface and less pitting than the surface of the Li metal anode. This suggests the formation of a robust, smoother, and more compact SEI on exemplary 90Li-Mg alloy anodes, without significant discontinuities and pinholes. The superior cycle life of the 90Li-Mg alloy anodes may be due to the improved stability of the 90Li-Mg alloy against anode-electrolyte interactions, even in the presence of polysulfides dissolved in the electrolyte.

[0131] Figure 12B shows another cross-sectional SEM micrograph of a self-supporting 90Li-Mg alloy anode taken from a lithium-sulfur coin cell after the initial discharge, according to several embodiments. Referring to Figure 12B, the exemplary 90Li-Mg alloy anode after the initial discharge shows a more compact surface layer disposed on top of a porous "host" structure near the anode-electrolyte interface, which also suggests the formation of a more stable SEI with the 90Li-Mg alloy anode.

[0132] Figure 12C shows cross-sectional SEM micrographs 1200C of self-supporting Li-Mg alloy anodes after initial discharge using energy-dispersive X-ray spectroscopy (EDS) elemental analysis, according to several embodiments. As shown in Figure 10C, high local concentrations of Mg were measured at the anode-electrolyte interface during EDS analysis of the cross-section of a cross-sectional 90Li-Mg anode sample. The high Mg content at the interface may suggest the formation of a more stable SEI with a 90Li-Mg anode. Without being constrained by any particular theory, the high Mg content may also suggest the ability of the 90Li-Mg anode to "self-regulate" Li ion exfoliation to produce a more uniform Li ion flux and a smoother interface after exfoliation. This may be explained by an increased kinetic barrier for Li ion diffusion in regions of local Li depletion and Mg enrichment.

[0133] Example 7. Comparison of cathode discharge capacity and capacity retention at C / 3 speed (charge and discharge) for an exemplary lithium-sulfur pouch cell having a self-supporting 90Li-Mg alloy anode and a cell having a Li metal anode. Figures 13A-13B show plots 1300A-1300B illustrating the cathode discharge capacity and capacity retention of exemplary lithium-sulfur pouch cells, including a self-supporting Li-Mg alloy anode, according to several embodiments. The cathode discharge capacity and capacity retention at C / 3 speeds (charge and discharge) were compared for exemplary lithium-sulfur pouch cells, including a self-supporting 90 Li-Mg alloy anode and a cell having a self-supporting Li metal anode. A specific energy of Li-S of approximately 175 W-h / kg was achieved in the pouch cell having a Li metal (100 wt% lithium) anode.

[0134] In contrast, pouch cells with a 100 μm thick 90Li-Mg alloy anode were characterized by a specific energy of approximately 223 W-h / kg (a 28% increase over Li metal anodes). Pouch cells with a 200 μm thick 90Li-Mg alloy anode were characterized by a lower specific energy of approximately 206 W-h / kg (an 18% increase). These results suggest that 100 μm thick 90Li-Mg alloy anodes are also preferable in terms of battery specific energy, as increasing the anode thickness also increases the anode weight. Compared to cells with a Li metal anode in the electrolyte (approximately 60 cycles), the cycle life with a 90Li-Mg anode at approximately 80% capacity retention (at least 100 cycles) was increased by at least 70%. Without being constrained by any particular theory, a self-supporting 90Li-Mg alloy anode with a thickness of at least 100 μm can increase the Li-S battery (pouch cell) specific energy by at least approximately 20%.

[0135] Example 8. Cathode discharge capacity of a lithium-sulfur coin cell containing a self-supporting Li-Mg alloy anode having binary and quaternary Li-Mg alloy compositions at a C / 3 discharge rate. Figures 14A-14B show plots 1400A-1400B illustrating the cathode discharge capacity and capacity retention of lithium-sulfur coin cells with quaternary self-supporting Li-Mg alloy anodes in several embodiments. The cathode discharge capacity and capacity retention of exemplary lithium-sulfur coin cells were compared using 90Li-Mg alloy anodes, Li-metal anodes, and 90Li-AZ31 quaternary alloy anodes at a C / 3 charge / discharge rate. The anode thickness was approximately 170 μm to 200 μm. The cathode coating amount was approximately 7.3 mg / cm². 2 ~7.6 mg / cm³ 2 A Celgard PP2075 dried polymer separator was used between the cathode and anode. The cathode capacity in each case was approximately 4 mAh / cm². 2 The E / S ratio was approximately 5. In Figures 14A-14B, the legends "SAM" and "MSE" represent two different suppliers of magnesium.

[0136] Referring to Figures 12A-12B, the cycle performance of cells with a 90Li-AZ31 anode was equivalent to that of cells with a 90Li-Mg alloy anode (approximately 200 cycles) while maintaining 80% discharge capacity. Cells with a Li-Mg alloy anode were more stable than cells with a Li metal anode (approximately 100-125 cycles).

[0137] Example 9. Cathode discharge capacity of a lithium-sulfur coin cell containing a self-supporting Li-Mg alloy anode having a ternary Li-Mg alloy composition at a C / 3 discharge rate. Figures 15A–15B show plots 1500A–1500B illustrating the Coulomb efficiency and discharge capacity retention of lithium-sulfur coin cells containing ternary self-supporting Li-Mg alloy anodes in several embodiments. The cathode discharge capacity, capacity retention, and CE (Coulomb efficiency) ratio of exemplary lithium-sulfur coin cells were compared using a Li metal anode and a 90 wt% Li:10 wt% Mg-Al ternary alloy anode at a C / 3 charge-discharge rate. The exemplary Li-Mg-Al alloy anode contained approximately 90 wt% Li, approximately 8 wt% Mg, and approximately 2 wt% Al, as well as approximately 90 wt% Li, approximately 5 wt% Mg, and approximately 5 wt% Al. Referring to Figures 15A–15B, over approximately 55 cycles, the discharge capacity (mAh / g) and capacity retention of cells using the exemplary Li-Mg-Al alloy anode were comparable to those of cells using a 90 Li-Mg anode. Furthermore, the CE ratio over approximately 100 cycles was also comparable.

[0138] Example 10. Cathode discharge capacity and capacity retention of an exemplary lithium-sulfur coin cell having a self-supporting 90Li-Mg alloy anode including a protective anode layer. Figure 16A shows plot 1600A illustrating the cathode discharge capacity and capacity retention of lithium-sulfur coin cells containing a self-supporting Li-Mg alloy anode with a protective anode layer in several embodiments. The cathode discharge capacity and capacity retention of exemplary lithium-sulfur coin cells in several embodiments were compared using a self-supporting Li metal anode, a 90Li-Mg alloy anode, and a self-supporting 90Li-Mg alloy anode with a polymer coating at a C / 3 charge / discharge rate. Referring to Figures 16A-16B, "G1" shows a self-supporting anode containing a 90Li-Mg alloy without any protective coating layer. "G2" shows a self-supporting 90Li-Mg alloy anode containing a PVDF protective coating layer. "G3" shows a self-supporting 90Li-Mg alloy anode containing a protective coating layer containing PETEA and PEGDMA. The cathode coating amount was approximately 7.6 mg / cm². 2 The cathode capacitance in each case was approximately 4 mAh / cm².2 It was. A Celgard 2500 separator was used between the cathode and the anode. The E / S ratio in an exemplary Li-S cell was approximately 5 (equivalent to an E / S of approximately 3 in the pouch cell due to dead space (the space around the sides of the electrode stack within the pouch cell)), and the N / P ratio was from approximately 2.0 to approximately 2.4.

[0139] Referring to FIGS. 16A - 16B, a Li-S cell having a protective coating layer containing PETEA and PEGDMA had a capacity retention of about 70% with a cathode discharge capacity of at least about 400 mAh / g, significantly extending the cycle life up to about 300 cycles. The delivered total energy of about 4.5 W-h was also improved by about 87.5% over the life of the cell (70% capacity retention).

[0140] Example 11. Cathode discharge capacity and capacity retention of an exemplary lithium-sulfur coin cell assembled with a 90Li-Mg alloy anode including at least one anode protective layer. FIGS. 17A - 17B show plots 1700A - 1700B illustrating the cathode discharge capacity and capacity retention of a lithium-sulfur coin cell including a 90Li-Mg alloy anode including at least one anode protective layer, according to some embodiments. Lithium-sulfur (''Li-S'') coin cells were assembled with a 90Li-Mg alloy anode, a 90Li-Mg alloy anode having a protective polymer coating, and a 90Li-Mg alloy anode including a reacted alloy layer disposed between the alloy and the protective polymer coating. The reacted alloy layer included a lithium-indium alloy layer. The protective polymer coating included PETEA and PEGDMA. The estimated thickness of the protective polymer coating on a dry basis was less than about 1 μm.

[0141] The tests were conducted at a C / 3 charge-discharge rate. The cathode coating amount in the cell was approximately 7.6 mg / cm 2 It was. The cathode capacity was approximately 4 mAh / cm 2A Celgard PP2075 separator was placed between the cathode and anode. The E / S ratio in the exemplary Li-S cell was approximately 5, which corresponds to an E / S of approximately 3 in the pouch cell due to dead space (space around the sides of the electrode stack in the pouch cell), and the N / P ratio was approximately 2.4 to 2.5. The electrolyte contained a fluorinated ether electrolyte comprising approximately 50:25:25 (vol%) 1,2-dimethoxyethane ("DME"):1,3-dioxolane ("DOL"):bis(2,2,2-trifluoroethyl) ether ("BTFE"), and approximately 0.4 M lithium bis(trifluoromethanesulfonyl) LiTFSI and approximately 2 wt% LiNO3.

[0142] Referring to Figures 17A-17B, “T1” shows a baseline cell containing a 90Li-Mg alloy anode without any anode protective layer. “T2” shows a cell containing a 90Li-Mg alloy anode containing PETEA and PEGDMA protective polymer coating layers. “T3” shows a cell containing a 90Li-Mg alloy anode containing a lithium-indium reacted alloy layer disposed between the activated alloy material and the protective polymer coating. The lithium-sulfur coin cell ("T3") containing the lithium-indium reacted alloy layer disposed between the activated alloy material (90Li-Mg) and the protective polymer coating was characterized by an improvement of approximately 20% cycle life with approximately 80% capacity retention and a cathode discharge capacity of at least approximately 450 mAh / g, compared to the performance of both the baseline cell ("T1") and the cell containing a 90Li-Mg alloy anode with a protective polymer coating ("T2").

[0143] Example 12. Cathode discharge capacity of a lithium-sulfur coin cell containing a self-supporting Li-Mg alloy anode with an anode protective coating. Table 2 provides a list of precursors associated with exemplary anode protective coating solutions according to several embodiments. The exemplary anode protective coating solution contained approximately 30 wt% solid (or precursor) and approximately 70 wt% solvent. The coating solution was applied to a lithium-magnesium alloy anode by spray coating. The polymer matrix contained polyethylene glycol dimethacrylate ("PEGDMA"). The coating application amount on the anode was approximately 125 μg / cm². 2 The curing of the anode coating precursor was performed using UV light. 2-hydroxy-2-methyl-1-phenylpropanone ("HMPP") was used as a photoinitiator for the curing process. [Table 2]

[0144] Figures 18A-18B illustrate the cathode discharge capacity and capacity retention of lithium-sulfur coin cells with anode protective coatings in several embodiments, as shown in plots 1800A-1800B. A PEGDMA polymer matrix containing a confined ionic liquid was prepared using the precursor compositions listed in Table 2 to form the anode protective coating. A commercially available Celgard® PP2075 separator was placed between the anode and cathode. The lithium-sulfur battery coin cell contained a 90 wt% Li-10 wt% Mg alloy anode and was cycled at a C / 3 charge / discharge rate. The E / S ratio was approximately 5 μL / mg.

[0145] Referring to Figures 18A-18B, the coin cell with anode protective coating outperformed the reference coin cell, as a cathode discharge capacity exceeding 450 mAh / g was measured when the capacity retention exceeded 70% throughout approximately 200 cycles.

[0146] Example 12. Cathode discharge capacity of a lithium-sulfur coin cell containing a self-supporting Li-Mg alloy anode with an anode protective coating. Table 3 provides a list of precursors for exemplary anode protective coating solutions according to several embodiments. Each exemplary anode protective coating solution contained approximately 3 wt% solid (or precursor) and approximately 97 wt% solvent. The coating solution was applied to a lithium-magnesium alloy anode by spray coating. The polymer matrix contained polyethylene glycol dimethacrylate ("PEGDMA"). The coating application amount on the anode was approximately 16 μg / cm². 2 ~Approx. 52μg / cm 2 The curing of the anode coating precursor was performed using a 550W-1000W heater with the thermal initiator 2,2'-azobis(2-methylpropionitrile) ("AIBN").

[0147] Figure 19 shows plot 1900 illustrating the retention of discharge capacity in lithium-sulfur coin cells with an anode protective coating in several embodiments. A PEGDMA polymer matrix containing a confined ionic liquid was prepared using the compositions listed in Table 3 below to form the anode protective coating. [Table 3]

[0148] A commercially available Celgard® PP2075 separator was placed between the anode and cathode. The lithium-sulfur battery coin cell contained a 90 wt% Li-10 wt% Mg alloy anode and was cycled at a C / 2 charge / discharge rate. The E / S ratio was approximately 5 μL / mg. Referring to Figure 19, the coin cell with the anode protective coating measured a cathode discharge capacity of over 500 mAh / g (not shown) with over 80% capacity retention throughout approximately 175 cycles, thus outperforming the reference coin cell.

[0149] When used herein, expressions referring to “at least one” or “one or more” in a list of items refer to any combination of those items, including a single member. For example, “at least one of a, b, or c” is intended to cover the possibilities of a only, b only, c only, a and b combination, a and c combination, b and c combination, and a, b, and c combination. Unless otherwise specified in this disclosure, to interpret the scope of the term “about” or “approximately,” the error boundary associated with a disclosed value (such as dimensions or operating conditions) is ±10% of the value shown in this disclosure. The error range associated with a value disclosed as a percentage is ±1% of the percentage shown. The word “substantially” when used before certain words includes the meanings of “corresponding to the specified range” and “corresponding largely to the specified range, but not entirely.”

[0150] Various modifications to the embodiments described herein may be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit or scope of this disclosure. Accordingly, the claims are not intended to be limited to the embodiments shown herein, but the broadest scope that is consistent with this disclosure, the principles disclosed herein, and novel features is permitted.

[0151] Furthermore, various features described herein in the context of separate embodiments may also be implemented in combination in a single embodiment. Moreover, various features described in the context of a single embodiment may also be implemented separately or in any preferred partial combination in multiple embodiments. Thus, features may be described above in combination with one another, and may even be initially claimed to be so, but one or more features from the claimed combination may, in some cases, be extracted from the combination, and the claimed combination may be a partial combination or a variation of a partial combination.

[0152] Similarly, while operations are shown in a specific order in the diagrams, this should not be understood as requiring that such operations be performed in a specific or sequential order shown, or that all illustrated operations be performed, in order to achieve the desired result. Furthermore, the diagrams may schematically illustrate another exemplary process in the form of a flowchart or flow diagram. However, other operations not illustrated can be incorporated into the exemplary process schematically illustrated. For example, one or more additional operations can be performed before, after, simultaneously with, or in between the illustrated operations. In some situations, multitasking and parallel processing may be advantageous. Furthermore, the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single product or encompassed in multiple products.

[0153] [Implementation Method] (1) A self-contained anode associated with a lithium-sulfur battery, an anode active material layer containing a lithium-magnesium (Li-Mg) alloy, The self-supporting anode comprises a polymer coating disposed on the anode active material, the coating comprising one or more of polyvinylidene fluoride (PVDF), pentaerythritol tetraacrylate (PETEA), or polyethylene glycol dimethacrylate (PEGDMA). (2) The self-supporting anode according to Embodiment 1, wherein the magnesium content in the Li-Mg alloy is approximately 5% by weight to approximately 15% by weight. (3) The self-supporting anode according to Embodiment 1, wherein the Li-Mg alloy contains about 90% by weight of lithium and about 10% by weight of Mg. (4) The self-supporting anode according to Embodiment 1, wherein the thickness of the self-supporting anode is approximately 50 μm to approximately 200 μm. (5) The self-supporting anode according to Embodiment 1, wherein the Li-Mg alloy further comprises one or more of titanium, zirconium, zinc, calcium, gallium, aluminum, or indium as additional alloying elements.

[0154] (6) The self-supporting anode according to Embodiment 1, wherein the Li-Mg alloy comprises about 90% by weight of Li and about 10% by weight of magnesium-aluminum-zinc alloy. (7) The self-supporting anode according to Embodiment 6, wherein the magnesium-aluminum-zinc alloy includes magnesium alloy AZ31. (8) The self-supporting anode according to Embodiment 6, wherein the magnesium-aluminum-zinc alloy includes magnesium alloy AZ61. (9) The self-supporting anode according to Embodiment 1, wherein the Li-Mg alloy comprises about 90% by weight of Li, about 5% to about 9.5% by weight of magnesium, and about 0.5% to about 5% by weight of aluminum. (10) The self-supporting anode according to Embodiment 1, wherein the Li-Mg alloy comprises about 90% by weight of Li, about 5% by weight of magnesium, and about 5% by weight of aluminum.

[0155] (11) The self-supporting anode according to Embodiment 1, wherein the Li-Mg alloy comprises about 90% by weight of Li, about 8% by weight of magnesium, and about 2% by weight of aluminum. (12) The self-supporting anode according to Embodiment 1, wherein the Li-Mg alloy comprises about 90% by weight of Li, about 9.5% by weight of magnesium, and about 0.5% by weight of aluminum. (13) The self-supporting anode according to Embodiment 1, wherein the thickness of the polymer coating is approximately 1 μm to approximately 10 μm. (14) The self-supporting anode according to Embodiment 1, further comprising a reacted alloy layer disposed on the anode active material layer, wherein the polymer coating is disposed on the reacted alloy layer. (15) The self-supporting anode according to Embodiment 14, wherein the reacted alloy layer comprises an alloy of lithium with one or more of tin, indium, gallium, or aluminum.

[0156] (16) The self-supporting anode according to Embodiment 14, wherein the thickness of the reacted alloy layer is less than approximately 1 μm. (17) an anode associated with a lithium-sulfur battery, Anode active material layer, A reacted alloy layer disposed as a surface layer on the anode active material layer, The anode comprises a polymer coating disposed on the reacted alloy layer. (18) The anode according to embodiment 17, wherein the anode comprises one or more of the following: a freestanding anode or an anode supported on a current collector. (19) The anode according to Embodiment 17, wherein the anode active material layer comprises one or more lithium metals or lithium-magnesium alloys. (20) The anode according to Embodiment 17, wherein the reacted alloy layer comprises an alloy of lithium with one or more of tin, indium, gallium, or aluminum.

[0157] (21) The anode according to Embodiment 17, wherein the polymer coating comprises one or more of polyvinylidene fluoride (PVDF), pentaerythritol tetraacrylate (PETEA), or polyethylene glycol dimethacrylate (PEGDMA). (22) an anode associated with a lithium-sulfur battery, Anode active material layer, an anode comprising an anode protective coating disposed on the anode active material layer, the anode protective coating comprising an ionic liquid confined within a polymer matrix. (23) The anode according to Embodiment 22, wherein the anode active material layer comprises a 90 wt% Li-10 wt% Mg alloy. (24) The anode according to Embodiment 22, wherein the polymer matrix comprises one or more acrylate groups or ethylene oxide groups. (25) The anode according to Embodiment 22, wherein the polymer matrix comprises one or more monomers or oligomers.

[0158] (26) The anode according to Embodiment 25, wherein the one or more monomers or oligomers include polyethylene glycol dimethacrylate (PEGDMA), pentaerythritol tetraacrylate (PETEA), polymethyl methacrylate (PMMA), polyethylene oxide (PEO), polyethylene glycol diacrylate (PEGDA), crosslinked polymer pentaerythritol tetraacrylate-polyethylene glycol dimethacrylate (PETEA-PEGDMA), or crosslinked polymer poly(vinylidene fluoride-hexafluoropropylene copolymer) (PVDF-HFP). (27) The ionic liquid is 1-ethyl-3-methylimidazolium (Emim), 1-butyl-3-methylimidazolium (Bmim), N-propyl-N-methylpyrrolidinium (Pyr 13 ), 1-butyl-1-methylpyrrolidinium (Pyr 14 ), 1-methyl-1-(2-methoxyethyl)pyrrolidinium (Pyr 1201 ), N-methyl-N-propylpiperidinium (PP 13 ), or 1-butyl-1-methylpiperidinium (PP 14 The anode according to Embodiment 22, comprising a cation, which includes one or more of the following: (28) The anode according to Embodiment 22, wherein the ionic liquid comprises an anion comprising one or more of bis(fluorosulfonyl)imide (FSI), bis(trifluoromethanesulfonyl)imide (TFSI), or dicyanamide (DCA). (29) The ionic liquid is 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EmimFSI), N-propyl-N-methylpyrrolidinium bis(fluorosulfonyl)imide (Pyr 13FSI), N-propyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr 13 TFSI), 1-butyl-1-methylpyrrolidinium bis(fluorosulfonyl)imide (Pyr 14 FSI), 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr 14 TFSI), 1-ethyl-3-methylimidazolium dicyanamide (Emim DCA), or 1-methyl-1-(2-methoxyethyl)pyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr 1201 The anode according to Embodiment 22, comprising one or more of the TFSIs. (30) The anode according to Embodiment 22, wherein the anode protective coating further comprises one or more salts comprising lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), sodium bis(fluorosulfonyl)imide (NaFSI), sodium bis(trifluoromethanesulfonyl)imide (NaTFSI), or lithium nitrate (LiNO3).

[0159] (31) The anode according to embodiment 22, wherein the thickness of the anode protective coating is 10 μm. (32) The anode according to Embodiment 22, wherein the amount of ionic liquid confined within the polymer matrix is ​​about 10% by weight to about 40% by weight. (33) A lithium-sulfur battery, A self-supporting anode containing 90 wt% Li-10 wt% Mg alloy, A polymer coating comprising one or more of polyvinylidene fluoride (PVDF), pentaerythritol tetraacrylate (PETEA), or polyethylene glycol dimethacrylate (PEGDMA) disposed on the self-supporting anode, A lithium-sulfur battery comprising a fluorinated ether electrolyte containing one or more lithium bis(trifluoromethanesulfonyl) (LiTFSI) or LiNO3. (34) The lithium-sulfur battery according to embodiment 33, wherein the thickness of the self-supporting anode is approximately 100 μm. (35) The lithium-sulfur battery according to Embodiment 33, wherein the concentration of LiTFSI in the electrolyte is about 0.1 M to about 2 M.

[0160] (36) The lithium-sulfur battery according to Embodiment 33, wherein the concentration of LiNO3 in the electrolyte is about 2% by weight to about 6% by weight. (37) The fluorinated electrolyte is A mixture containing approximately 0.4 M LiTFSI and approximately 2 wt% LiNO3, in a ratio of approximately 50:25:25 (vol%) of 1,2-dimethoxyethane (DME):1,3-dioxolane (DOL):bis(2,2,2-trifluoroethyl) ether (BTFE); Approximately 0.4 M LiTFSI and approximately 2 wt% LiNO3 are contained in a mixture of approximately 50:25:25 (vol %) DME:DOL:1,1,2,2-tetraethoxyethane (TEE); A mixture containing approximately 0.4 M LiTFSI and approximately 2 wt% LiNO3, in a ratio of approximately 50:25:25 (vol%) DME:DOL:1,1,2,2-tetrafluoroethyl 2,2,2-trifluoroethyl ether (TFETFE); Approximately 0.4 M LiTFSI and approximately 2 wt% LiNO3, in a ratio of approximately 60:20:10:10 (volume %) DME:DOL:TEE:TFETFE; A mixture containing approximately 0.4 M LiTFSI and approximately 2 wt% LiNO3, in a ratio of approximately 50:25:25 (vol%) DME:DOL:1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE); Approximately 0.4 M LiTFSI and approximately 2 wt% LiNO3 are contained in a mixture of approximately 50:25:25 (vol%) DME:DOL:1-fluorinated 1,4-dimethoxybutane (FDMB); or, A lithium-sulfur battery according to Embodiment 33, comprising one or more of approximately 1.0 M LiTFSI in approximately 50:50 (vol %) DOL:BTFE. (38) further comprising a cathode, wherein the cathode is Cathode board and, Disposed on the cathode substrate, one or more porous carbon layers containing sulfur, comprising one or more porous carbon layers including porous carbon aggregates of porous carbon primary nanoparticles, wherein each of the porous carbon primary nanoparticles Distributed around the center of each of the aforementioned porous carbon primary nanoparticles, and surrounding the inner porous carbon region, an inner porous shell, An outer porous shell, the outer porous shell surrounding an outer porous carbon region disposed between the inner shell and the outer shell, A lithium-sulfur battery according to embodiment 33, comprising an interconnected porous network disposed within the inner carbon region and the outer carbon region, and in fluid communication with the inner carbon region and the outer carbon region. (39) The lithium-sulfur battery according to embodiment 38, wherein the inner carbon region and the outer carbon region are characterized by the average pore size and average pore density associated with each region. (40) The lithium-sulfur battery according to embodiment 39, wherein the average pore size decreases radially from the center to the outer porous shell.

[0161] (41) The lithium-sulfur battery according to embodiment 38, further comprising one or more intermediate porous shells disposed between the inner porous shell and the outer porous shell, each of the intermediate porous shells surrounding its respective intermediate porous carbon region. (42) The lithium-sulfur battery according to Embodiment 38, wherein the porous carbon aggregate comprises one or more interconnected bundles of conductive graphene layers. (43) The lithium-sulfur battery according to Embodiment 42, wherein the graphene layers are arranged as one or more stacks that are connected to each other and define a 3D porous scaffold structure including mesopores. (44) The lithium-sulfur battery according to embodiment 43, wherein one or more stacks are arranged substantially orthogonally to one another. (45) The lithium-sulfur battery according to Embodiment 42, wherein the graphene layer is characterized by a length dimension of approximately 50 nm to 200 nm.

[0162] (46) The lithium-sulfur battery according to Embodiment 42, wherein the graphene layer comprises one or more single-layer graphene (SLG), minority-layer graphene (FLG), or multilayer graphene (MLG). (47) The porous carbon aggregate has an I of about 0.95 to about 1.05 D / I G A lithium-sulfur battery according to embodiment 38, characterized by a Raman spectroscopic signature having a ratio. (48) The lithium-sulfur battery according to Embodiment 38, wherein the sulfur-to-carbon weight ratio in one or more porous carbon layers is approximately 1:5 to 10:1. (49) The packing density of the one or more porous carbon layers is at least 7 mg / cm³ 2 The lithium-sulfur battery described in embodiment 38. (50) The lithium-sulfur battery according to Embodiment 38, wherein the thickness of one or more porous carbon layers is approximately 10 μm to approximately 200 μm.

[0163] (51) The lithium-sulfur battery according to Embodiment 38, wherein the average size of the porous primary carbon nanoparticles is about 20 nm to about 50 nm. (52) The lithium-sulfur battery according to Embodiment 38, wherein the porous carbon aggregate is characterized by an electrical conductivity of about 500 S / m to 20,000 S / m when compressed at a pressure of about 12,000 pounds per square inch (psi). (53) The lithium-sulfur battery according to Embodiment 38, wherein the average size of the porous carbon aggregates is at least 1 μm. (54) The lithium-sulfur battery according to embodiment 38, further comprising a separator disposed between the anode and the cathode. (55) The lithium-sulfur battery according to Embodiment 54, wherein the separator includes a microporous single-layer polypropylene film.

[0164] (56) The lithium-sulfur battery according to embodiment 54, wherein the separator includes a ceramic-coated material. (57) A lithium-sulfur battery, Lithium alloy anode and an anode protective coating disposed on the anode, the anode protective coating comprising an ionic liquid confined within a polymer matrix, Cathode and, A lithium-sulfur battery comprising a liquid fluorinated ether electrolyte containing one or more of lithium nitrate (LiNO3) or lithium bis(trifluoromethanesulfonyl) (LiTFSI). (58) The lithium-sulfur battery according to embodiment 57, wherein the anode includes a self-supporting lithium alloy anode. (59) The lithium-sulfur battery according to Embodiment 58, wherein the Li-alloy comprises a 90 wt% Li-10 wt% Mg alloy. (60) The lithium-sulfur battery according to Embodiment 57, wherein the polymer matrix comprises one or more acrylate groups or ethylene oxide groups.

[0165] (61) The lithium-sulfur battery according to Embodiment 57, wherein the amount of the ionic liquid confined within the polymer matrix is ​​about 10% by weight to about 40% by weight. (62) A roll-to-roll method for distributing one or more anode protective layers on an anode active material associated with a lithium-sulfur battery, Placing one or more anode active material layers and one or more alloyed metal layers in the rolling mill as feed material layers, The process of passing the supply material layer through the rolling mill, wherein each surface of the one or more anode active material layers is in contact with the one or more alloyed metal layers within the rolling mill, The roll-to-roll method, comprising forming a reacted alloy layer in situ on each surface of the anode active material layer during rolling, wherein the reacted alloy layer is a reaction product of the one or more anode active material layers reacting with the one or more alloyed metal layers. (63) A method for distributing one or more protective layers on the anode active material associated with a lithium-sulfur battery, Using the method of Embodiment 62, a reacted alloy layer is formed on each surface of the anode active material, The method comprising depositing a polymer coating on the reacted alloy layer disposed on each surface of the anode active material. (64) The method according to Embodiment 63, wherein the thickness of the reacted alloy layer is less than 1 μm. (65) The method according to Embodiment 63, wherein the polymer coating comprises one or more of polyvinylidene fluoride (PVDF), pentaerythritol tetraacrylate (PETEA), or polyethylene glycol dimethacrylate (PEGDMA).

[0166] (66) The method according to embodiment 63, wherein the thickness of the polymer coating is less than 1 μm. (67) A method for providing an anode protective coating on an anode associated with a lithium-sulfur battery, The coating solution is prepared by mixing a precursor, comprising one or more monomers or oligomers, an ionic liquid, one or more lithium salts, and a polymerization initiator, in a solvent. Applying the coating solution to the anode, Initiating the polymerization of one or more monomers or oligomers, Removing the solvent by drying, The method comprises curing the coating to form a polymer matrix into which the ionic liquid has been injected, wherein the amount of precursor in the coating solution is about 3% by weight to about 30% by weight. (68) The amount of the polymer matrix injected with the ionic liquid on the anode is approximately 10 μg / cm². 2 ~about 600μg / cm 2 The method according to embodiment 67.

Claims

1. A self-contained anode associated with a lithium-sulfur battery, an anode active material layer containing a lithium-magnesium (Li-Mg) alloy, The self-supporting anode comprises a polymer coating disposed on the anode active material, the coating comprising one or more of the following: polyvinylidene fluoride (PVDF), pentaerythritol tetraacrylate (PETEA), or polyethylene glycol dimethacrylate (PEGDMA).

2. The self-supporting anode according to claim 1, wherein the magnesium content in the Li-Mg alloy is about 5% by weight to about 15% by weight.

3. The self-supporting anode according to claim 1, wherein the Li-Mg alloy contains about 90% by weight of lithium and about 10% by weight of Mg.

4. The self-supporting anode according to claim 1, wherein the thickness of the self-supporting anode is approximately 50 μm to approximately 200 μm.

5. The self-supporting anode according to claim 1, wherein the Li-Mg alloy further comprises one or more of titanium, zirconium, zinc, calcium, gallium, aluminum, or indium as additional alloying elements.

6. The self-supporting anode according to claim 1, wherein the Li-Mg alloy comprises about 90% by weight of Li and about 10% by weight of magnesium-aluminum-zinc alloy.

7. The self-supporting anode according to claim 6, wherein the magnesium-aluminum-zinc alloy includes magnesium alloy AZ31.

8. The self-supporting anode according to claim 6, wherein the magnesium-aluminum-zinc alloy includes magnesium alloy AZ61.

9. The self-supporting anode according to claim 1, wherein the Li-Mg alloy comprises about 90% by weight of Li, about 5% to about 9.5% by weight of magnesium, and about 0.5% to about 5% by weight of aluminum.

10. The self-supporting anode according to claim 1, wherein the Li-Mg alloy comprises about 90% by weight of Li, about 5% by weight of magnesium, and about 5% by weight of aluminum.

11. The self-supporting anode according to claim 1, wherein the Li-Mg alloy comprises about 90% by weight of Li, about 8% by weight of magnesium, and about 2% by weight of aluminum.

12. The self-supporting anode according to claim 1, wherein the Li-Mg alloy comprises about 90% by weight of Li, about 9.5% by weight of magnesium, and about 0.5% by weight of aluminum.

13. The self-supporting anode according to claim 1, wherein the thickness of the polymer coating is approximately 1 μm to approximately 10 μm.

14. The self-supporting anode according to claim 1, further comprising a reacted alloy layer disposed on the anode active material layer, wherein the polymer coating is disposed on the reacted alloy layer.

15. The self-supporting anode according to claim 14, wherein the reacted alloy layer comprises an alloy of lithium with one or more of tin, indium, gallium, or aluminum.

16. The self-supporting anode according to claim 14, wherein the thickness of the reacted alloy layer is less than approximately 1 μm.

17. an anode associated with a lithium-sulfur battery, Anode active material layer, A reacted alloy layer disposed as a surface layer on the anode active material layer, The anode comprises a polymer coating disposed on the reacted alloy layer.

18. The anode according to claim 17, wherein the anode comprises one or more of the following: a freestanding anode or an anode supported on a current collector.

19. The anode according to claim 17, wherein the anode active material layer comprises one or more of lithium metal or lithium-magnesium alloy.

20. The anode according to claim 17, wherein the reacted alloy layer comprises an alloy of lithium with one or more of tin, indium, gallium, or aluminum.

21. The anode according to claim 17, wherein the polymer coating comprises one or more of polyvinylidene fluoride (PVDF), pentaerythritol tetraacrylate (PETEA), or polyethylene glycol dimethacrylate (PEGDMA).

22. an anode associated with a lithium-sulfur battery, Anode active material layer, an anode comprising an anode protective coating disposed on the anode active material layer, the anode protective coating comprising an ionic liquid confined within a polymer matrix.

23. The anode according to claim 22, wherein the anode active material layer contains a 90% by weight Li-10% by weight Mg alloy.

24. The anode according to claim 22, wherein the polymer matrix comprises one or more acrylate groups or ethylene oxide groups.

25. The anode according to claim 22, wherein the polymer matrix comprises one or more monomers or oligomers.

26. The anode according to claim 25, wherein the one or more monomers or oligomers include polyethylene glycol dimethacrylate (PEGDMA), pentaerythritol tetraacrylate (PETEA), polymethyl methacrylate (PMMA), polyethylene oxide (PEO), polyethylene glycol diacrylate (PEGDA), crosslinked polymer pentaerythritol tetraacrylate-polyethylene glycol dimethacrylate (PETEA-PEGDMA), or crosslinked polymer poly(vinylidene fluoride-hexafluoropropylene copolymer) (PVDF-HFP).

27. The aforementioned ionic liquid is 1-ethyl-3-methylimidazolium (Emim), 1-butyl-3-methylimidazolium (Bmim), N-propyl-N-methylpyrrolidinium (Pyr １３ ), 1-butyl-1-methylpyrrolidinium (Pyr １４ ), 1-methyl-1-(2-methoxyethyl)pyrrolidinium (Pyr １２０１ ), N-methyl-N-propylpiperidinium (PP １３ ), or 1-butyl-1-methylpiperidinium (PP １４ The anode according to claim 22, comprising a cation which includes one or more of the following.

28. The anode according to claim 22, wherein the ionic liquid comprises an anion comprising one or more of bis(fluorosulfonyl)imide (FSI), bis(trifluoromethanesulfonyl)imide (TFSI), or dicyanamide (DCA).

29. The ionic liquid is 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EmimFSI), N-propyl-N-methylpyrrolidinium bis(fluorosulfonyl)imide (Pyr １３ FSI), N-propyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr １３ TFSI), 1-butyl-1-methylpyrrolidinium bis(fluorosulfonyl)imide (Pyr １４ FSI), 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr １４ TFSI), 1-ethyl-3-methylimidazolium dicyanamide (Emim DCA), or 1-methyl-1-(2-methoxyethyl)pyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr １２０１ TFSI), and the anode according to claim 22 contains one or more of them.

30. The anode protective coating is lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), sodium bis(fluorosulfonyl)imide (NaFSI), sodium bis(trifluoromethanesulfonyl)imide (NaTFSI), or lithium nitrate (LiNO). ３ The anode according to claim 22, further comprising one or more salts including ).

31. The anode according to claim 22, wherein the thickness of the anode protective coating is 10 μm.

32. The anode according to claim 22, wherein the amount of ionic liquid confined within the polymer matrix is ​​about 10% by weight to about 40% by weight.

33. Lithium-sulfur battery, A self-supporting anode containing 90 wt% Li-10 wt% Mg alloy, A polymer coating comprising one or more of polyvinylidene fluoride (PVDF), pentaerythritol tetraacrylate (PETEA), or polyethylene glycol dimethacrylate (PEGDMA) disposed on the self-supporting anode, Lithium bis(trifluoromethanesulfonyl) (LiTFSI) or LiNO ３ A lithium-sulfur battery comprising a fluorinated ether electrolyte containing one or more of the following:

34. The lithium-sulfur battery according to claim 33, wherein the thickness of the self-supporting anode is approximately 100 μm.

35. The lithium-sulfur battery according to claim 33, wherein the concentration of LiTFSI in the electrolyte is about 0.1 M to about 2 M.

36. LiNO in the electrolyte ３ The lithium-sulfur battery according to claim 33, wherein the concentration of is approximately 2% by weight to approximately 6% by weight.

37. The fluorinated electrolyte, Approximately 0.4 M of LiTFSI and approximately 2% by weight of LiNO ３ Including approximately 50:25:25 (vol%) 1,2-dimethoxyethane (DME):1,3-dioxolane (DOL):bis(2,2,2-trifluoroethyl) ether (BTFE); Approximately 0.4 M of LiTFSI and approximately 2% by weight of LiNO ３ Including approximately 50:25:25 (vol %) DME:DOL:1,1,2,2-tetraethoxyethane (TEE); Approximately 0.4 M of LiTFSI and approximately 2% by weight of LiNO ３ Contains approximately 50:25:25 (vol%) DME:DOL:1,1,2,2-tetrafluoroethyl 2,2,2-trifluoroethyl ether (TFETFE); Approximately 0.4 M of LiTFSI and approximately 2% by weight of LiNO ３ Including approximately 60:20:10:10 (volume %) DME:DOL:TEE:TFETFE; Approximately 0.4 M of LiTFSI and approximately 2% by weight of LiNO ３ Contains approximately 50:25:25 (vol%) DME:DOL:1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE); Approximately 0.4 M of LiTFSI and approximately 2% by weight of LiNO ３ Including approximately 50:25:25 (vol%) DME:DOL:1-fluorinated 1,4-dimethoxybutane (FDMB); or, A lithium-sulfur battery according to claim 33, comprising one or more of approximately 1.0 M of LiTFSI in approximately 50:50 (vol %) DOL:BTFE.

38. Further comprising a cathode, the cathode is Cathode board and, Disposed on the cathode substrate, one or more porous carbon layers containing sulfur, comprising one or more porous carbon layers including porous carbon aggregates of porous carbon primary nanoparticles, wherein each of the porous carbon primary nanoparticles Distributed around the center of each of the aforementioned porous carbon primary nanoparticles, and surrounding the inner porous carbon region, an inner porous shell, An outer porous shell, the outer porous shell surrounding an outer porous carbon region disposed between the inner shell and the outer shell, A lithium-sulfur battery according to claim 33, comprising an interconnected porous network disposed within the inner carbon region and the outer carbon region, and in fluid communication with the inner carbon region and the outer carbon region.

39. The lithium-sulfur battery according to claim 38, wherein the inner carbon region and the outer carbon region are characterized by the average pore size and average pore density associated with each region.

40. The lithium-sulfur battery according to claim 39, wherein the average pore size decreases radially from the center to the outer porous shell.

41. The lithium-sulfur battery according to claim 38, further comprising one or more intermediate porous shells disposed between the inner porous shell and the outer porous shell, each of the intermediate porous shells surrounding its respective intermediate porous carbon region.

42. The lithium-sulfur battery according to claim 38, wherein the porous carbon aggregate comprises one or more interconnected bundles of conductive graphene layers.

43. The lithium-sulfur battery according to claim 42, wherein the graphene layers are arranged as one or more stacks that are connected to each other and define a 3D porous scaffold structure including mesopores.

44. The lithium-sulfur battery according to claim 43, wherein one or more stacks are arranged substantially orthogonally to one another.

45. The lithium-sulfur battery according to claim 42, wherein the graphene layer is characterized by a length dimension of approximately 50 nm to 200 nm.

46. The lithium-sulfur battery according to claim 42, wherein the graphene layer comprises one or more of single-layer graphene (SLG), minority-layer graphene (FLG), or multi-layer graphene (MLG).

47. The porous carbon aggregate has an I of about 0.95 to about 1.05 Ｄ / I Ｇ A lithium-sulfur battery according to claim 38, characterized by a Raman spectroscopic signature having a ratio.

48. The lithium-sulfur battery according to claim 38, wherein the sulfur-to-carbon weight ratio in one or more porous carbon layers is approximately 1:5 to 10:

1.

49. The packing density of the one or more porous carbon layers is at least 7 mg / cm³ ２ The lithium-sulfur battery according to claim 38.

50. The lithium-sulfur battery according to claim 38, wherein the thickness of one or more porous carbon layers is approximately 10 μm to approximately 200 μm.

51. The lithium-sulfur battery according to claim 38, wherein the average size of the porous primary carbon nanoparticles is about 20 nm to about 50 nm.

52. The lithium-sulfur battery according to claim 38, wherein the porous carbon aggregate is characterized by an electrical conductivity of about 500 S / m to 20,000 S / m when compressed at a pressure of about 12,000 pounds per square inch (psi).

53. The lithium-sulfur battery according to claim 38, wherein the average size of the porous carbon aggregate is at least 1 μm.

54. The lithium-sulfur battery according to claim 38, further comprising a separator disposed between the anode and the cathode.

55. The lithium-sulfur battery according to claim 54, wherein the separator comprises a microporous single-layer polypropylene film.

56. The lithium-sulfur battery according to claim 54, wherein the separator comprises a ceramic-coated material.

57. Lithium-sulfur battery, Lithium alloy anode and an anode protective coating disposed on the anode, the anode protective coating comprising an ionic liquid confined within a polymer matrix, Cathode and, Lithium nitrate (LiNO) ３ A lithium-sulfur battery comprising a liquid fluorinated ether electrolyte containing one or more of ) or lithium bis(trifluoromethanesulfonyl) (LiTFSI).

58. The lithium-sulfur battery according to claim 57, wherein the anode includes a self-supporting lithium alloy anode.

59. The lithium-sulfur battery according to claim 58, wherein the Li-alloy comprises 90% by weight Li-10% by weight Mg alloy.

60. The lithium-sulfur battery according to claim 57, wherein the polymer matrix comprises one or more acrylate groups or ethylene oxide groups.

61. The lithium-sulfur battery according to claim 57, wherein the amount of the ionic liquid confined within the polymer matrix is ​​about 10% by weight to about 40% by weight.

62. A roll-to-roll method for distributing one or more anode protective layers on an anode active material associated with a lithium-sulfur battery, Placing one or more anode active material layers and one or more alloyed metal layers in the rolling mill as feed material layers, The process involves passing the supply material layer through the rolling mill, wherein each surface of the one or more anode active material layers is in contact with the one or more alloyed metal layers within the rolling mill. The roll-to-roll method, comprising forming a reacted alloy layer in situ on each surface of the anode active material layer during rolling, wherein the reacted alloy layer is a reaction product of the one or more anode active material layers that react with the one or more alloyed metal layers.

63. A method for distributing one or more protective layers on the anode active material associated with a lithium-sulfur battery, Using the method of claim 62, a reacted alloy layer is formed on each surface of the anode active material, The method comprising depositing a polymer coating on the reacted alloy layer disposed on each surface of the anode active material.

64. The method according to claim 63, wherein the thickness of the reacted alloy layer is less than 1 μm.

65. The method according to claim 63, wherein the polymer coating comprises one or more of polyvinylidene fluoride (PVDF), pentaerythritol tetraacrylate (PETEA), or polyethylene glycol dimethacrylate (PEGDMA).

66. The method according to claim 63, wherein the thickness of the polymer coating is less than 1 μm.

67. A method for providing an anode protective coating on an anode associated with a lithium-sulfur battery, The coating solution is prepared by mixing a precursor, comprising one or more monomers or oligomers, an ionic liquid, one or more lithium salts, and a polymerization initiator, in a solvent. Applying the coating solution to the anode, Initiating the polymerization of one or more monomers or oligomers, Removing the solvent by drying, The method comprises curing the coating to form a polymer matrix into which the ionic liquid has been injected, wherein the amount of precursor in the coating solution is about 3% by weight to about 30% by weight.

68. The amount of the polymer matrix injected with the ionic liquid on the anode is approximately 10 μg / cm². ２ ~Approx. 600 μg / cm ２ The method according to claim 67.

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