Production method and working principle for pre-expansion of chalcogenide-based electrode prior to reaction with alkali / alkaline earth metal

Abstract

To provide a method for expanding chalcogenide materials, an apparatus therefor, and an electrode and a battery comprising a chalcogenide material.SOLUTION: The present invention relates to the working principle and production methods for the pre-expansion of sulfur and / or other chalcogenides such as selenium or tellurium, and / or a mixture of any two or more. The present invention further relates to an electrode / cathode comprising sulfur and / or a mixture of sulfur allotropes, for example, crystalline, glassy, amorphous, and / or polymeric (e.g., β-, γ-, and / or ω-phasic) sulfur and / or a mixture of any two or more sulfur allotropes. The sulfur is photonically / electronically / thermally pre-expanded to a state where it has a density equivalent to a metal sulfide, such as Li2S. The expansion is carried out before electrode / cathode fabrication for the realization of alkali and / or alkali earth metal / ion batteries, such as LiS batteries.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure generally relates to principles of operation and methods of manufacture for volumetric pre-expansion of pure and / or doped chalcogenides (including, but not limited to, S, Se, Te) and / or mixtures of any two or more chalcogenides. The present disclosure further relates to electrodes / cathodes comprising volume pre-expanded chalcogenides, or more specifically, but not limited to, sulfur, including, for example, crystalline, glassy, amorphous, polymeric (e.g., β-, γ-, and / or ω-phase) and / or photo-sulfur allotropes having a tadpole structure, crystalline allotropes having a circumferential ring structure, and / or mixtures of any two or more allotropes, where the sulfur is optically / electronically / thermally pre-expanded or partially pre-expanded, and in the case of LiS, 1.66 g / cm 3 The resulting state has a density comparable to that of metal sulfides such as (corresponding to 100% depth of discharge of a LiS battery).

[0002] The present disclosure further relates to methods and apparatus for pre-expanding a chalcogenide, more preferably a mixture of sulfur and / or other chalcogenides (i.e., selenium, tellurium, etc.) with a sulfur allotrope, which generates an internal cavity in addition to the open porosity already present, which limits access to the electrolyte and primarily acts as a buffer space for the volumetric expansion of the electrode / cathode discharge products during cell (or battery) operation. The present disclosure also relates to an electrode / cathode comprising a pre-expanded chalcogenide, more preferably sulfur, and a method for manufacturing the same, for achieving an electrochemical energy storage device and / or alkaline / alkaline earth metal / ion battery with an E / S ratio of less than 1.5 ml / g, such as a LiS battery, a Na—S battery, an Al—S battery, a Mg—Sd battery, etc. [Background technology]

[0003] Due to the serious energy and environmental crisis and the rapid depletion of natural resources (i.e., fossil fuels), highly efficient, environmentally friendly, and renewable energy sources are being actively researched. Lithium-sulfur (LiS) batteries are being actively investigated as one of the leading candidates for next-generation energy storage due to their unprecedented theoretical capacity (1675 mAh / g), high energy density (2600 Wh / kg), natural abundance, cost-effectiveness, and environmental sustainability. However, the use of LiS batteries is limited to niche applications, and widespread and industrial implementation of LiS technology is hindered by the insulating properties of sulfur (electronic conductivity at room temperature ∼5 × 10). -30 S / cm), formation of lithium polysulfides (LPS species: LiS n ,4≦n≦8), the LPS shuttling effect, the parasitic growth of lithium dendrites, the unstable solid electrolyte interface (SEI), poor cycling stability, and safety hazards that can result in severe capacity loss or battery failure during cycling.

[0004] During the discharge / charge process, volume fluctuations occur within the positive and negative electrodes of an electrochemical cell. For example, during discharge, sulfur in the electrode / cathode expands due to conversion reactions that produce solid products (mostly lithium disulfide: LiS or LiS / LiS), while the metallic Li anode contracts due to Li oxidation / stripping. The opposite process occurs during charge, where the Li metal anode expands due to lithium plating. The opposing effects (i.e., expansion and contraction) occur simultaneously during the charge / discharge process. As a result of chemical / electrochemical and / or redox reactions, the large volume fluctuations (~79%) exhibited by, for example, sulfur and lithium disulfide between charge / discharge states result in insufficient sulfur utilization, causing serious drawbacks that result in poor cycling stability and severe capacity fade. Similar behavior has also been reported for other monovalent, divalent, and trivalent metal ions, including Na, K, Ca, Mg, Al, and Zn. For example, in the case of Na-S batteries, the volume fluctuations are as high as ~152%.

[0005] Current slurry-based processes are widely used in industry for the fabrication of electrodes, regardless of battery chemistry. They are also used to fabricate sulfur-containing cathodes for LiS batteries. However, they have limitations: they cannot create complex electrode structures with the tailored porosity necessary to efficiently accommodate metal sulfides such as LiS or sulfur during charge and discharge, nor can they provide open pores to buffer electrode thickness variations caused by volumetric fluctuations between charge and discharge products. Furthermore, current slurry-based processes have a maximum porosity of approximately 45%. Increasing porosity beyond this value can only be achieved by reducing the calendering pressure, which leads to low compaction and excessive dead weight / volume that must be filled with electrolyte, resulting in reduced structural integrity, lower energy per volume, and lower power density. Calendering is a key process / step in the efficient formation of conductive pathways (networking) within battery cathodes. This is achieved through the interaction of various particles (sulfur, binder, additives) in the slurry. Cathode porosity is also important for achieving a high-energy cathode. For example, current cathodes can have a porosity of approximately 45%, which allows for compensation for volume fluctuations (79% expansion and contraction of sulfur-based cathodes during charge and discharge cycles) and allows space for electrolyte to occupy the voids inside the cathode. In LiS batteries, charging (contraction) and discharging (expansion) also facilitates the movement of electrolyte into and out of the electrode / cathode. A volume fluctuation of approximately 79% is essential for achieving maximum sulfur utilization (theoretical ~100%), resulting in a specific capacity of approximately 1675 mAh / g (i.e., the theoretical capacity of sulfur) for sulfur-based cathodes. However, the space available for compensation of volume fluctuations during discharge in such slurry-based sulfur cathodes is about 45%, which leads to pore clogging, and as a result, most cathodes end up reaching a capacity of ∼1100 mAh / g or less at 1 C due to pore blockage.This is even more severe in NaS batteries due to the higher volume of the discharge product NaS (~152%), resulting in a further decrease in the utilization of the sulfur active material in the slurry-based cathode. When lithiation or sodiation occurs, the expansion affects the pores, displacing the electrolyte from the electrode / cathode and significantly affecting the transport, diffusion, and convection processes in the electrochemical cell. The presence of electrolyte in the pores of the sulfur electrode / cathode is essential for effective electrode kinetics and high sulfur utilization to obtain high-capacity electrodes / cathode. For example, in an electrochemical cell, the sulfur density is 2.07 g / cm after lithiation (i.e., discharge). 3 to 1.66 g / cm 3 This results in the formation of solid LiS in the fully discharged state. This equivalent density of sulfur can be achieved by pre-expansion, which compensates for the negative volume fluctuations in LiS cells during cell operation. In metal-chalcogenide batteries such as LiS batteries, the sulfur-containing cathode undergoes constant cycles of expansion and contraction. During this process, the movement of lithium ions and electrons occurs in the cathode of Li + / e - Known as percolation, the cell components fragment and then rebuild while simultaneously building up and recovering. In long-term operation, this process has a negative impact on all aspects of an alkali-ion / sulfur battery or LiS battery.

[0006] In conventional slurry-based sulfur cathodes, sulfur is impregnated / encapsulated in a porous conductive matrix, such as porous carbon, graphene, carbon nanotubes, metal-organic frameworks, or a combination of various conductive host structures, to facilitate electron transport, buffer volume expansion, mitigate polysulfide dissolution, and, most importantly, stabilize the sulfur within the enclosed micro-meso-macroporous voids. Conventional host structures, such as carbon-based ones, such as carbide-derived carbons or CO2-etched carbon nanofibers, as described in U.S. Pat. No. 10,991,944, and porous 3D graphene scaffold structures, such as those described in U.S. Pat. No. 11,335,911, allow sulfur to infiltrate a suitable host at the single particle level, become part of aggregates, and ultimately clusters. In most of these slurry-based cathodes, sulfur exists in its most stable crystalline phase, i.e., with orthorhombic sulfur. Another possible embodiment is to provide structural stabilization of sulfur, e.g., monoclinic sulfur, such as gamma sulfur (γ-sulfur), in the cathode. This is achieved by providing enclosed volume / voids in the host, into which sulfur resides, at ∼2.16 g / cm. 3 Generally, the monoclinic γ phase is metastable; however, even with the use of an appropriate host with voids designed to trap / confine γ-sulfur, the density can be stabilized to ∼2.07 g / cm. 3 The transition from γ-sulfur to the stable orthorhombic α-phase, which has a lower density, would be impossible because there is no volume for expansion. The orthorhombic α-phase requires more space than the γ-phase to expand due to the difference in density. However, despite some progress, electrodes still suffer from low electronic conductivity, poor cycling performance, and low C-rate capability. Summary of the Invention

[0007] The present disclosure further relates to a method for expanding a chalcogenide material, comprising the steps of: a. providing a chalcogenide material; b. covering (or coating) the chalcogenide material with at least one layer of graphene oxide; c. immersing the coated chalcogenide material in a treatment liquid (and / or gas); d. subjecting the immersed coated chalcogenide material to photon and / or electron irradiation (particularly photon irradiation), thereby increasing the temperature of the chalcogenide material to a range of 320-420°C, more preferably 365°C, thereby expanding the chalcogenide material; e. Cooling the expanded chalcogenide material to a temperature in the range of −196 to 4° C., more preferably below −35° C., wherein the cooling medium is a treatment liquid and / or gas (particularly the treatment liquid).

[0008] The present disclosure relates to electrodes (e.g., cathodes) comprising chalcogenide materials: a) the chalcogenide material is photonically and / or electronically and / or thermally expanded to a state exhibiting the same density state as the corresponding metal chalcogenide; b) the apparent density of the chalcogenide material after expansion is within the range of the true density of the corresponding metal chalcogenide and the chalcogenide (e.g., chalcogenide material) itself; c) the internal voids of the chalcogenide material represent (or correspond to) a buffer volume available for volume compensation during charge / discharge of the battery; d) The manufacturing process (eg, of the electrode) is characterized by interactive co-expansion of the chalcogenide material with, for example, a processing liquid and / or gas.

[0009] According to non-limiting embodiments, true density may be understood as the density of a substance (e.g., a metal chalcogenide or chalcogenide material) in a vacuum, for example, and may be understood as being independent of external conditions such as buoyancy in air or gravity. In contrast, the apparent density of a substance may be defined, for example, by its weight in air per volume. In other words, apparent density may be understood as, for example, effective density, which takes into account voids and structural changes due to cycling, whereas true density may be understood as, for example, the theoretical density of a chalcogenide material (or metal chalcogenide) in a fully compressed, void-free state.

[0010] According to non-limiting embodiments, the electrode characteristics a) and d) above may be understood to refer to the as-fabricated electrode, i.e., these characteristics may describe properties of the electrode that result from its fabrication process and (as described below) result in the unique structural characteristics of the fabricated electrode.

[0011] According to a non-limiting embodiment, feature b) may be understood to refer to the results of the manufacturing process, i.e., to the structure and properties of the manufactured electrode, in particular the apparent density of the chalcogenide material.

[0012] Also according to a non-limiting embodiment, characteristic c) may be understood to refer to the result of the manufacturing process, i.e., to the structure and properties of the manufactured electrodes, in particular the internal porosity of the electrodes in the battery and their function during operation. All characteristics a) to d) can thus specify the electrodes.

[0013] For example, according to feature a), for example, sulfur (i.e., a chalcogenide material) may be expanded to a point where it matches the density state of a metal chalcogenide, meaning that the sulfur has reached an expanded state similar to that of the lithium-sulfur compound that forms during discharge. This means that the sulfur in the cathode has expanded to a level that makes its structure more porous, with an apparent density corresponding to that of the lithium-sulfur compound.

[0014] Further, according to an embodiment, feature b) may provide that after expansion, for example, the apparent density of sulfur may be within the range of the true densities of both sulfur and lithium polysulfide. This range means that after expansion, the sulfur material is in a density state somewhere between its fully compressed state (true density of sulfur) and its chemically combined state with lithium (true density of lithium polysulfide).

[0015] According to non-limiting embodiments, the term "same density" may mean a similar density, for example, an approximately similar density. The term equivalent density (as mentioned below) can mean "exactly the same density" or at least "the same density" as described.

[0016] According to non-limiting embodiments, features a) and b) can explain the difference between full (complete) compensation and partial compensation (i.e., partial compensation for closed pores, as described in more detail below) of the volume expansion of chalcogenide materials.

[0017] Also, according to a non-limiting embodiment, the internal voids of characteristic c) can be referred to as closed pores / closed porosity.

[0018] According to non-limiting embodiments, the interactive (or synergistic) co-expansion (or simultaneous expansion) referred to in feature d) can specifically mean that the chalcogenide material and the processing liquid and / or gas expand simultaneously (i.e., expand together) during the manufacturing process. As a result, the manufactured chalcogenide material can have certain properties (as described in more detail below) that would not exist without interactive co-expansion. In particular, interactive co-expansion can avoid overheating, structural collapse, and evaporation of sulfur. More specifically, simultaneous liquid / vapor expansion can result in internal voids (i.e., pores / voids). For example, gas may be generated within the porous voids of the sulfur wafer. For example, the processing liquid may convert to steam and expand inside the voids along with the steam and gas, counteracting the expansion caused by photon-induced heating of the sulfur wafer. This immediate reaction prevents structural collapse of the sulfur voids.

[0019] According to embodiments, the surface of the chalcogenide material is covered, coated and / or stabilized with a two-dimensional material, preferably a graphene-based material such as graphene oxide, which crosslinks with the chalcogenide during the expansion process.

[0020] According to non-limiting embodiments, the chalcogenide material can act as a redox active material. The mass content can be, for example, ≧85% and can exhibit hierarchical porosity. For example, open pores can be utilized for electrolyte / catholyte, and closed pores can act as buffer volumes for volume compensation.

[0021] According to an embodiment, the chalcogenide material is selected from sulfur (S), selenium (Se) and tellurium (Te), in particular the chalcogenide material is sulfur, more preferably the chalcogenide material is a sulfur wafer (in particular a self-standing wafer).

[0022] According to non-limiting embodiments, the characteristic volume compensation for discharge products is divided between open and closed porosity. Closed porosity can compensate for 0.25-100% of the total electrochemically induced theoretical volume expansion (equivalent to 79%), e.g., from sulfur to LiS. Open porosity can compensate for the remaining 0-50% of the total volume change of metal disulfide products due to discharge.

[0023] In a further embodiment, the final product in the fully discharged state may be NaS, and volume compensation can be partially compensated for by a combination of, for example, 90% or less of the closed porosity available in the sulfur wafer and, for example, 45% or less of the open porosity available in the electrolyte. Of the theoretical 157% conversion of sulfur to NaS, the remaining 22% may not be compensated for. Therefore, the volume variation of such a battery can be limited to 22% (i.e., 157-135%).

[0024] The electrode may have a limited operating range (e.g., when used as a battery cathode): for example, the end product of discharge may be limited to, e.g., Na2S2, whose theoretical 67% volume variation can be completely compensated for by closed porosity.

[0025] The present disclosure further relates to a laser-based apparatus for expanding and cooling a chalcogenide material to a state having a density comparable to that of a metal chalcogenide.

[0026] According to an embodiment, the wavelength of the photons is between 430 nm and 100 nm, preferably between 430 nm and 254 nm, more preferably 390 nm.

[0027] The present disclosure further relates to FLA / IPL (Flash Lamp Annealing (FLA) / Intense Pulsed Light (IPL))-based devices in which a chalcogenide material expands and cools to a state having a density similar to that of a metal chalcogenide. Devices utilizing FLA / IPL (i.e., FLA / IPL sources) may include or use a xenon lamp, which may be part of a xenon flash lamp assembly, for example. For example, the intensity of FLA may be higher than the intensity of IPL.

[0028] According to an embodiment, the wavelength of the photons may be in the range of 800 to 170 nm, more preferably 450 to 250 nm.

[0029] According to an embodiment, the FLA / IPL source provides 25 J / cm 2 More than 120 J / cm 2 It produces a high intensity photon flux with a greater fluence.

[0030] According to an embodiment, the laser source has a power of 100 J / cm 2 and 400 J / cm 2 or more preferably in the range of 250 J / cm 2 It produces a high intensity photon flux with a larger fluence.

[0031] According to an embodiment, the laser beam travels through the processing / cooling liquid.

[0032] The present disclosure further relates to an electrode (particularly a cathode) comprising an expanded chalcogenide material, the material being prepared according to a method such as that described above (eg, embodiment 3 or 4).

[0033] The present disclosure further relates to a battery comprising the above-described electrode (particularly the cathode).

[0034] According to an embodiment, the battery has an electrolyte to sulfur (E / S) ratio of less than 1.99 ml / g.

[0035] The present disclosure further relates to an apparatus for carrying out the above-described method, said apparatus comprising: a chamber into which wafers containing chalcogenide materials (particularly sulfur-containing wafers) are placed; A radiation source for photoexpanding chalcogenide materials (especially sulfur); and Control system to limit the expansion process Includes.

[0036] The apparatus further comprises: a movable arm carrying a radiation source (particularly a laser source) and including means for providing a flow of liquid to the wafer; and A wafer holding means having a rotation function, which can rotate clockwise or counterclockwise at a desired speed (preferably 15 to 20 rotations per minute); It has.

[0037] According to an embodiment, the expanded chalcogenide material (especially expanded sulfur) has a density of 1.70 g / cm 3 Less than (e.g., 1.66 g / cm 3 ) density.

[0038] According to an embodiment, the photon irradiation is carried out using a laser, in particular an FLA laser source, a UV laser source or an IPL laser source.

[0039] According to an embodiment, the FLA laser source, UV laser source or IPL laser source has a power of 25 J / cm 2 or more, preferably 120 J / cm 2 It produces a high intensity photon flux with a greater fluence.

[0040] According to an embodiment, steps d and e are carried out simultaneously.

[0041] According to an embodiment, the liquid is selected from water, fluorinert, ethanol, CO2 and isopropyl alcohol or any mixture thereof.

[0042] The term "chalcogenide material" refers to a material containing one chalcogenide or a mixture of two or more chalcogenides. Furthermore, the term "chalcogenide material" refers to pure and / or doped chalcogenides. Furthermore, the term "chalcogenide material" refers to chalcogenide allotropes, such as crystalline and / or glassy and / or amorphous and / or polymeric (e.g., β- and / or γ- and / or ω-phase) and / or photo-sulfur allotropes with a tadpole structure and / or crystalline allotropes with a cyclic ring structure, and / or mixtures of two or more allotropes. Preferably, the chalcogenide material is selected from sulfur (S), selenium (Se), and tellurium (Te), and particularly preferably, the chalcogenide material is sulfur. Preferably, the chalcogenide material is a chalcogenide wafer, especially a sulfur wafer. More preferably, the wafer is a free-standing wafer.

[0043] The term "expansion" refers to a state in which the actual dimensions of a material change. Preferably, the expansion is thermal expansion. According to a preferred embodiment, chalcogenide materials (especially sulfur) are, for example, Li + , Na + , K. + , Ca 2+ , Mg 2+ , Al 3+ , Zn 2+ The expansion to this state is referred to as "pre-expansion" or "pre-expanding" in the context of this disclosure.

[0044] The treatment liquid is selected from water, fluorinert, ethanol, CO2 and isopropyl alcohol or any mixture thereof. The treatment liquid may or may not be gas saturated.

[0045] According to the present disclosure, photon irradiation or photonic irradiation is preferably carried out by means of a laser, in particular by means of an FLA, UV or IPL laser source.

[0046] A further embodiment of the present disclosure relates to an electrode / cathode comprising a chalcogenide-based active material, preferably sulfur, which is photo-preexpanded to a density comparable to that of a metal sulfide, such as LiS. The preexpansion is performed prior to use in the fabrication of an electrode / cathode for implementing an alkali or alkaline earth metal / ion battery, such as a LiS battery. The preexpansion of sulfur is achieved by tailoring the expansion process, taking advantage of sulfur's high thermal volumetric expansion coefficient. This preexpansion ensures that sulfur expands little or only negligibly during chemical / electrochemical and / or redox reactions, such as lithiation and / or sodiation, that occur during battery charge and discharge.

[0047] A further embodiment relates to an electrode / cathode comprising a mixture of chalcogenide allotropes, more preferably a mixture of sulfur allotropes, including crystalline, glassy, amorphous, and polymeric phases (e.g., β-, γ-, and ω-phase sulfur). The sulfur is optically, electrically, and thermally pre-expanded to a density comparable to that of metal sulfides, such as LiS, before being used in the fabrication of an electrode / cathode to realize an alkali or alkaline earth metal / ion battery, such as a LiS battery. The pre-expansion of pure / doped sulfur and / or other chalcogenides and / or their mixtures is achieved by taking advantage of their high thermal volumetric expansion coefficients to tailor the expansion process. This pre-expansion ensures that pure and doped sulfur and / or other chalcogenides undergo no or negligible further expansion during chemical / electrochemical and / or redox reactions, such as lithiation and / or sodiation, that occur during the charging and discharging of the battery.

[0048] In another embodiment, the electrode / cathode comprises a mixture of chalcogenides containing sulfur, selenium, and tellurium, which has been optically, electrically, and thermally pre-expanded to a density comparable to that of metal sulfides. The pre-expansion is performed before use in the fabrication of an electrode / cathode for an alkali or alkaline earth metal / ion battery, such as a LiS battery. The pre-expansion of the chalcogenide mixture is achieved by taking advantage of its high thermal volumetric expansion coefficient to tailor the expansion process. This pre-expansion ensures that the chalcogenide mixture undergoes no or negligible further expansion due to chemical / electrochemical and / or redox reactions, such as lithiation and / or sodiation, that occur during the charging and discharging of the battery.

[0049] Another embodiment of the present disclosure relates to a method and apparatus for pre-expansion of sulfur and / or other chalcogenides, including selenium, tellurium, and / or any mixture of two or more chalcogenides. The pre-expansion is performed using optically, electrically, or thermally induced heating, such as through the use of a laser or other high-energy light source. The resulting pre-expanded sulfur and / or chalcogenides can then be used in the fabrication of electrodes / cathodes to realize alkali or alkaline earth metal / ion batteries, such as LiS batteries. The pre-expansion ensures that the sulfur and / or chalcogenides undergo no or negligible further expansion during chemical / electrochemical and / or redox reactions, such as lithiation and / or sodiation, that occur during charging.

[0050] Another embodiment of the present disclosure relates to electrodes / cathodes made from sulfur and / or mixtures of sulfur allotropes, such as crystalline, glassy, amorphous, or polymeric sulfur, which have been optically, electrically, or thermally pre-expanded to densities comparable to those of metal sulfides, such as LiS. This pre-expanded sulfur and / or mixtures of sulfur allotropes can then be used to fabricate electrodes / cathodes for use in alkaline or alkaline earth metal / ion batteries, such as LiS batteries.

[0051] A further embodiment of the present disclosure relates to a method for pre-expanding sulfur and / or other chalcogenides, such as selenium or tellurium, to achieve densities similar to those of metal sulfides using photon or thermal energy. This pre-expanded sulfur and / or chalcogenide mixture can then be used to fabricate electrodes / cathodes for use in alkali or alkaline earth metal / ion batteries, such as LiS batteries.

[0052] Another embodiment of the present disclosure relates to an apparatus for pre-expanding sulfur and / or other chalcogenides using photonic or thermal energy. The apparatus includes a chamber for containing sulfur and / or other chalcogenides and a photonic or thermal energy source to expand the sulfur and / or other chalcogenides to a desired density. The pre-expanded sulfur and / or chalcogenide mixture can then be used to fabricate electrodes / cathodes for use in alkali or alkaline earth metal / ion batteries, such as LiS batteries.

[0053] In further embodiments, the present disclosure relates to an electrode / cathode composed of sulfur and / or a combination of various sulfur allotropes, including crystalline, glassy, amorphous, or polymeric forms such as β-, γ-, and ω-phase sulfur. This electrode / cathode is specifically designed for use in alkali or alkaline earth metal / ion batteries, such as LiS batteries. Prior to use, the mixture of sulfur and sulfur allotropes is photo- / thermally pre-expanded to a density comparable to that of a metal sulfide, such as LiS, which is the end product of a fully discharged LiS battery. The pre-expansion of sulfur is achieved through the exploitation of sulfur's unusually high thermal volumetric expansion coefficient. This allows for the tailored pre-expansion of sulfur and other chalcogenides, such as selenium and tellurium, as well as combinations of these materials. The pre-expansion ensures that sulfur does not expand or expands only to a negligible extent as a result of chemical / electrochemical and / or redox reactions with metal ions, such as Li, Na, K, Ca, Mg, Al, and Zn. In addition to electrodes / cathodes, the present disclosure also relates to methods and apparatus used for pre-expansion of sulfur and other chalcogenides, which allows for efficient and consistent production of electrodes / cathodes for use in LiS batteries and other metal / ion batteries.

[0054] In a further embodiment, the present disclosure relates to an electrode / cathode comprising sulfur and / or a mixture of allotropes, such as crystalline, glassy, amorphous, or polymeric sulfur, as well as mixtures of any two or more of these allotropes. The electrode / cathode is designed for use in an alkali or alkaline earth metal / ion battery, such as a LiS battery. Prior to use, the sulfur undergoes a pre-expansion process in which it is photo- or thermally expanded to a density comparable to that of a metal sulfide, such as LiS. This pre-expansion is made possible by sulfur's unusually high thermal volumetric expansion coefficient. Pre-expansion of sulfur allows for negligible or no expansion as a result of chemical or electrochemical reactions during battery operation, such as lithiation or sodiation. The present disclosure also includes methods and apparatus for pre-expansion of sulfur and other chalcogenides, such as selenium and tellurium, as well as mixtures of two or more of these elements. This pre-expanded sulfur and / or sulfur allotrope mixture can then be used to fabricate electrodes / cathodes for use in alkaline and / or alkaline earth metal / ion batteries.

[0055] In a further embodiment, the present disclosure relates to a novel type of electrode / cathode for use in lithium-sulfur batteries and other types of alkaline or alkaline earth metal / ion batteries. The electrode / cathode is fabricated from sulfur and / or a mixture of various sulfur allotropes, such as crystalline, glassy, amorphous, or polymeric sulfur. These materials are pre-expanded via a photothermal or thermal heating process to have densities comparable to those of metal sulfides such as LiS. This pre-expansion process is carried out before the sulfur and / or sulfur allotropes are used to fabricate the electrode / cathode. One unique feature of the present disclosure is that it utilizes sulfur's unusually high thermal volumetric expansion coefficient to tailor the pre-expansion process. This allows sulfur and / or other chalcogenides, such as selenium or tellurium, to be pre-expanded to a state where they undergo no or negligible further expansion as a result of chemical or electrochemical reactions, such as lithiation or sodiation, during battery operation. The present disclosure also relates to methods and apparatus for pre-expansion of sulfur and / or other chalcogenides. This includes the design and construction of the equipment used in this process and its use to heat the material optically or thermally to the desired density. Overall, the use of pre-expanded sulfur and / or sulfur allotropes in the electrodes / cathodes of lithium-sulfur batteries or other metal / ion batteries has the potential to potentially increase their energy density and also improve the performance and durability of these batteries.

[0056] In further embodiments, the present disclosure relates to electrodes / cathodes comprising sulfur and / or mixtures of sulfur allotropes, such as crystalline, glassy, amorphous, or polymeric sulfur, for use in alkaline and / or alkaline earth metal / ion batteries, such as LiS batteries. In some embodiments, a method for photo- / thermally pre-expanding sulfur expands the sulfur to a state with a density comparable to that of metal sulfides, such as LiS in a fully discharged LiS battery. Pre-expansion is performed before the sulfur is used in the electrode / cathode, and the resulting pre-expanded sulfur has the advantage that it does not further expand or expands only negligibly as a result of chemical / electrochemical reactions with monovalent, divalent, or trivalent metal ions, such as lithiation or sodiation. In some embodiments, sulfur may be mixed with one or more other chalcogenides, such as selenium or tellurium, to further improve the performance of the electrode / cathode. The present disclosure also relates to methods and apparatus for pre-expanding sulfur and / or other chalcogenides.

[0057] The present disclosure has the following advantages: a. The use of pre-expanded sulfur in electrodes / cathodes can significantly improve the performance of alkaline and / or alkaline earth metal / ion batteries, such as LiS batteries, by increasing material utilization, reducing capacity fading, and increasing cycle life. b. The method and apparatus for pre-expansion of sulfur and / or other chalcogenides is easily implemented and can be scaled up for industrial production. c. The present disclosure provides a simple and cost-effective method to overcome the challenges posed by the unusually high thermal volume expansion coefficients of sulfur and other chalcogenides. [Brief explanation of the drawings]

[0058] [Figure 1] Linear and volumetric expansion coefficients of various metals. [Figure 2] Graph showing sulfur density versus temperature. [Figure 3]Parameters that affect the energy density of LiS batteries, including the electrolyte-to-sulfur ratio. (See: https: / / doi.org / 10.1007 / s41918-018-0010-3) [Figure 4(a)] Schematic (isometric) view of an apparatus for the sequential expansion of chalcogenide materials, or more specifically sulfur wafers. The apparatus comprises the following elements: a chamber for containing a sulfur wafer and / or a mixture of sulfur allotropes (401) that rotates together with expansion-compensating wafer holder pins (402) present in a wafer holder (403); an irradiation source (405) for optically / thermally expanding the mixture of sulfur and / or sulfur allotropes, further comprising a cooling liquid (404) fed into the cooling head via a supply pipe (406) that delivers the process liquid; an arm / drive (407) supporting the movement of the laser source in the x, y, and z directions along with angular rotation and tilt; an actuator (408) for wafer rotation and the entire apparatus (409); and a control system for regulating the expansion process to achieve the desired density of the pre-expansion of the mixture of sulfur and / or sulfur allotropes. *Not to scale. [Figure 4(b)] Schematic of a sequential expansion apparatus with sulfur wafers (top view). *Not to scale. [Figure 5]This is a schematic (side view) of an apparatus for nanobubble-assisted pre-expansion of chalcogenide materials, or more specifically, sulfur wafers. The apparatus comprises an aerator (501) capable of generating nanobubbles, a stand (502) capable of holding a chalcogenide wafer (503), and a wafer holder (504) that allows for volumetric expansion of the chalcogenide wafer. This assembly is immersed in a cooling / processing liquid (505). The apparatus further comprises an irradiation guide crystal (506) that collects photons from a source (507), such as a xenon lamp that is part of a xenon flash lamp assembly (508). The apparatus further comprises a lamp holder (509). The double-jacketed apparatus comprises an outer wall (511), an inner wall (512), and an AAO membrane (510), as shown in the schematic. *Not to scale. [Figure 6] Simplified schematic of grown sulfur wafer processing equipment. The setup consists of a chamber (601) holding the mother liquid (602) and a wafer holder (603) with grown sulfur wafers (604). *Not to scale. [Figure 7]This simplified schematic diagram of the pre-expansion process shows a grown sulfur wafer (604) composed of aligned seeds coated with graphene oxide layers (703), which also act as an electron percolation network (701) on which sulfur crystals grow (702), immersed in a treatment solution at room temperature. The grown sulfur wafer then undergoes a pre-expansion process in which the temperature of the chalcogenide wafer is raised to 420°C, resulting in the expansion of the chalcogenide (702) within the wafer along with the reduction of GO, i.e., the formation of rGO (705). Cooling (or quenching) the pre-expanded sulfur wafer results in the contraction of the chalcogenide. Due to the contraction of the chalcogenide to rGO, internal voids (706) form within the wafer, acting as a structural stabilizing layer. *Not to scale. [Figure 8] Graph showing the volume expansion of sulfur upon electrochemical reaction with alkali ions, namely Li and Na, and the subsequent compensation of this volume expansion between open and closed pores.

[0059] [Figure description] In the following, the present disclosure will be explained in more detail according to some non-limiting embodiments, as schematically illustrated by the figures.

[0060] To overcome the problems of the prior art, as described at the beginning of this disclosure, in this disclosure, a sulfur cathode (prior to use in an alkali-ion / sulfur battery) is optically, electrically, and thermally expanded to a state with a density similar to that of LiS (the product of a fully discharged LiS battery) and crosslinked into a two-dimensional material such as GO, which, after sulfur expansion, reacts with sulfur to deoxidize GO, forming reduced graphene oxide (rGO), and simultaneously crosslinking with sulfur radicals at the interface between GO and sulfur. Sulfur has unusually high linear and volumetric expansion coefficients (as shown in Figure 1), which can be advantageously used to tailor sulfur expansion. Upon expansion and crosslinking, the rGO acts as a shell and mechanical support, inducing sulfur contraction from the center of the sulfur core to the shell upon cooling. (Figure 6 visualizes the core-to-shell contraction and sulfur chains.) Figure 2 shows the correlation between sulfur density and temperature.

[0061] In principle, pre-expansion can be achieved by, for example, Li + , Na + , K. + , Ca 2+ , Mg 2+ , Al 3+ , Zn 2+ This means that sulfur does not further expand or only partially or negligibly expands due to chemical / electrochemical and redox reactions, such as lithiation and / or sodiation, with mono-, di- or trivalent metal ions such as sulphur ions, ...

[0062] Another aspect of a successful lithium-sulfur battery is the specific ratio of electrolyte to sulfur, measured in milliliters per gram (ml / g). Current LiS batteries typically use an E / S ratio of about 5 ml / g. This ratio is a critical factor in determining the commercial viability of the battery, as shown in Figure 3. Careful consideration of the E / S ratio is important when designing and evaluating LiS batteries.

[0063] The present disclosure relates to an apparatus and method for pre-expansion of chalcogenides (S, Se, Te) and / or mixtures of any two or more thereof, or more specifically pure and / or doped sulfur, or more specifically sulfur wafers (EP 3913705), but not limited thereto. Pre-expansion can be performed in several ways. Herein, two unique methods are proposed for the first time: 1. Instantaneous Expansion (or Flash Expansion), and 2. Sequential Expansion. The present disclosure further relates to an electrode / cathode comprising a pre-expanded chalcogenide, or more specifically sulfur and / or a mixture of sulfur allotropes, where the sulfur is photo- / thermally pre-expanded to a state having a density similar to that of metal sulfides. Overall, in the process, the incident photons / electrons and / or heat treatment cause the expansion of sulfur due to an increase in the local temperature within the sulfur, which leads to an increase in volume due to the high volume expansion coefficient of sulfur, 2.08 g / cm 3 to 1.66 g / cm 3 The density of the sulfur decreases to 0.1, followed by a series of cross-linking reactions of sulfur with two-dimensional materials such as GO, resulting in the formation of a robust outer shell. Upon cooling to room temperature, the robustness of the cross-linked GO layer at the GO / sulfur interface prevents the shrinkage of the coated sulfur from shell to core, but favors shrinkage internally, i.e., from core to shell, creating an internal cavity, as shown in Figure 6.

[0064] Prior to pre-expansion, the two-dimensional material and / or thin layer / thin layers of materials are transparent to the UV spectrum and can be bonded to chalcogenide-based materials, more preferably sulfur, while providing high electronic conductivity and transparency to charge carrier ions such as graphene oxide for redox operations. The thin layer / thin layers are coated onto an electrode / cathode, which may contain crystalline, glassy, amorphous, and / or polymeric (e.g., β-, γ-, and / or ω-phase) sulfur and / or a mixture of any two or more sulfur allotropes, such as porous sulfur wafers (EP 3913705), by dip coating, vacuum filtration, spray coating, spin coating, bar coating, slot-die coating, roll-to-roll printing, screen printing, flexographic printing, lithographic printing, inkjet printing, film stretching, or, more preferably, electrostatically driven layer-by-layer (LbL) assembly, or, more preferably, by immersing the wafer in a liquid dispersion of the two-dimensional material followed by IR / air drying. In this process, nanosheets of the two-dimensional material, or more preferably GO, are electrostatically attached to the surface of a chalcogenide-based wafer, more preferably a sulfur wafer. The LbL coating (i.e., dipping / emerging) and drying process is repeated several times until the desired thickness of the two-dimensional material on the porous wafer is reached (thickness range: 5-50 nm, or more preferably 20 nm or more preferably 10 nm).

[0065] As a result of the pre-expansion process, the resulting sulfur electrode possesses two types of porosity: i) open porosity, which originates from the wafer growth of chalcogenide-based cathodes as described in EP 3913705 A1 and is accessible to charge carriers in the electrolyte, and ii) internal voids, which originate from photon / electron beam and / or thermally induced sulfur expansion and subsequent cross-linking with the two-dimensional material shell, enhancing the structural stability of the pre-expanded sulfur wafer and, upon cooling to room temperature or lower, leading to an inner volume contraction of the sulfur, i.e., from the core toward the shell, forming internal voids. The newly formed internal voids increase the redox-active surface area between the active material and the charge carriers in the electrolyte, in addition to providing a volume buffer space for discharge products, i.e., metal sulfides, more preferably lithium disulfide, LiS. After the prescribed pre-expansion, the chalcogenides, or more specifically sulfur, can be used to fabricate electrodes / cathodes for the realization of alkali and / or alkaline earth (Li, Na, K, Ca, Mg, Al, Zn, etc.) metals / ions, or more specifically LiS batteries. In principle, pre-expansion means that the sulfur expands only negligibly or partially, or no further expansion occurs. The upper limit of volumetric compensation provided by this method is limited by the boiling point of sulfur at 1 atmosphere (~444°C); expansion beyond this operating window can be achieved by applying pressures higher than 1 atmosphere and modifying the boiling point of sulfur to a higher temperature. The present disclosure benefits from sulfur's unusually high coefficient of linear / volumetric expansion (Figure 1), which can be used to control pre-expansion, as well as for other pure and doped chalcogenides, such as Se and Te, or mixtures of two or more.

[0066] Method 1. Sequential Expansion The apparatus for sequential expansion is shown in Figure 5(ab). The apparatus consists of a metal / glass body with an adjustable / movable FLA / UV / IPL laser source with a collecting coolant / water flow, which is mounted on top of the apparatus as shown in Figure 4(a). The movable FLA / UV / IPL laser source acts as a writing head and has the ability to write a defined / programmable pattern on the wafer. The FLA / UV / IPL laser source has an output of 25 J / cm. 2 , preferably 120 J / cm 2 The device has the capability of generating a high-intensity photon flux with a fluence greater than 1000 kJ / s, sufficient to expand chalcogenides and / or mixtures of any two or more chalcogenides, or more specifically, but not limited to, pure and / or doped sulfur. The device further includes a sample / wafer holder with a rotation function, as shown in Figure 4(b). The sample holder can be rotated clockwise and / or counterclockwise at a desired speed (preferably 15-20 revolutions per minute). A cooling liquid flow focuses the FLA / UV / IPL laser beam and cools the heated / molten sulfur, minimizing the risk of wafer collapse. Suitable process liquids, such as water, ethanol, CO2, or IPA, or a mixture of two or more of any of these, can be used in the flow, allowing for instant heat exchange. The process liquid temperature is maintained between -110 and +4°C and controlled using a heat exchanger. The device may or may not further include a second channel for spraying a treatment / cooling liquid to cool the sample / wafer from the opposite side of the sample / wafer holder during the pre-expansion process while preventing the structure from collapsing.

[0067] Working principle Pre-expansion of pure and / or doped chalcogenides and / or mixtures of any two or more (but not limited to) can be performed using the sequential expansion method. For example, pre-expansion of a free-standing layered porous monolithic sulfur wafer (EP 3913705) can be performed using the flash expansion method. Unlike the flash expansion method, in which the entire wafer is simultaneously exposed to light, the sequential expansion method works on the principle of spot heating and cooling. In this process, a free-standing porous monolithic sulfur wafer (EP 3913705) is placed in a sample / wafer holder as illustrated in Figure 4(b). The FLA / UV / IPL laser / radiation source delivers a high-intensity photon flux (25-120 J / cm) to the sulfur wafer. 2 The photons emitted from the FLA / UV / IPL source are absorbed by the sulfur wafer, resulting in localized heating, expansion, and ring-opening polymerization (ROP). The flow of the treatment liquid immediately cools the polymeric sulfur and helps constrain the wafer structure. During the process, the temperature of the treatment liquid is maintained between -110 and +4°C to avoid overheating, structural collapse, and sulfur vaporization.

[0068] Method 2: Nanobubble-assisted pre-expansion The apparatus for nanobubble assisted pre-expansion is depicted in Figure 5. The apparatus includes a closed system of metal / glass containers with a FLA / UV / IPL laser source on top. The FLA / UV / IPL laser source provides 25 J / cm. 2 , preferably 120 J / cm 2The laser source is suitable for generating a high-intensity photon flux with a larger fluence, and is suitable for expanding chalcogenides and / or mixtures of any two or more chalcogenides, or more specifically, but not limited to, pure and / or doped sulfur, or more preferably, sulfur wafers (EP 3913705). The laser source further includes a focusing lens, which transmits photons from the FLA / UV / IPL laser source directly to the sulfur wafer and may or may not be partially immersed in the processing solution to improve the intensity of the photons irradiating the wafer by mitigating the photon refraction / reflection principle. The metal / glass container is a jacketed container with a vacuum between the inside and outside of the container, and the inner wall of the outer container may be coated with a photon-reflecting coating, such as barium sulfate, to enable total reflection and focusing of the photons toward the sulfur wafer. Additionally, the vacuum between the outside and inside of the container prevents heat / mass transfer with the external system. FLA / UV / IPL laser source is 25J / cm 2 , preferably 120 J / cm 2The device is suitable for generating high-intensity photon fluxes with greater fluence, and is suitable for expanding chalcogenides and / or mixtures of any two or more chalcogenides, more specifically (but not limited to) pure and / or doped sulfur, or more preferably sulfur wafers (European Patent Application Publication No. 3913705). The device further includes a wafer holder that can be immersed in a processing liquid (water, fluorinate, ethanol, CO2, IPA, and / or a mixture of any two or more) and functions to dissipate heat from the sulfur wafer during irradiation. The device further includes an aerator disk attached to the bottom of the vessel through which a suitable mixture of gases, such as, but not limited to, CO2, is passed. The gas introduced through the aerator is further cooled before introduction into the metal / glass vessel by passing it through an auxiliary heat exchanger connected to the outside, which maintains the temperature between -110 and 40°C. An anodic alumina membrane (AAO) is placed between the aerator and the wafer holder. Nanopores in the AAO membrane facilitate and allow the formation of nanobubbles, which then migrate toward the irradiated wafer due to their lower density compared to the surrounding process liquid. The distance / height between the aerator, AAO membrane, and wafer holder can be adjusted depending on the desired parameters. Furthermore, due to the principle of buoyancy, the nanobubbles also act as a local support for the sulfur wafer undergoing photon / electron and / or thermal treatment.

[0069] Working principle Nanobubble pre-expansion of pure and / or doped chalcogenides and / or mixtures of any two or more chalcogenides (but not limited to these) is performed by simultaneous flash expansion and nanobubble cooling to create internal voids. In this method, a desired gas, such as CO2, is introduced via an aerator into a vessel containing a treatment solution maintained at a temperature between -110 and 4°C. The introduced bubbles can have a range of sizes depending on the pore size of the aerator; however, reduction of gas bubble size is possible by placing an AAO membrane directly above the aerator. Due to the low density of the introduced gas bubbles and the limited transport through the AAO membrane due to their larger size, these bubbles accumulate below the voids and are retained by the AAO membrane. In this case, gas transport is possible only through the AAO membrane, which contains nano-unidimensional pores, thus resulting in the formation of nanobubbles with submicrometer pores, more preferably with dimensions smaller than 200 nm. These nanobubbles then travel towards the sulfur wafer, which is then exposed to a high intensity photon flux (preferably 120 J / cm) from the FLA / UV / IPL laser. 2 The FLA / UV / IPL laser wavelengths are kept between the blue and UV ranges, resulting in a pre-expansion of the chalcogenide wafer, preferably sulfur, which aids / aims to cool and preserve the structural integrity of the sulfur wafer, but also aids in the creation of internal voids.

[0070] To induce ROP, ultrafast processing times (milliseconds) are sufficient using high-energy photons at appropriate frequencies, such as UV-C in the 200-280 nm range and / or VUV in the 100-200 nm range. In the process, photons emitted from the FLA / UV / IPL device are absorbed by the sulfur wafer, resulting in localized heating and ring-opening polymerization (ROP). Most of the photon energy delivered to the sulfur wafer is due to flash-heating and a 1.66 g / cm 3The sulfur is consumed in the sequential expansion to a dense state. The surrounding processing liquid immediately cools the molten / polymeric sulfur and helps to constrain the wafer structure. During the flash expansion process, the temperature of the processing liquid is maintained between -110 and +4°C using a heat exchanger to avoid overheating, structural collapse, and vaporization of the sulfur. The processing liquid is circulated using an external pump.

[0071] All processes mentioned in this disclosure involve two steps, preferably performed simultaneously: light-induced expansion of sulfur at ~360°C and cooling from -110 to +4°C (ideally +4°C). To achieve this, an energy source with minimal thermal inertia, such as FLA / UV / IPL, is preferably used as the heating source, and cooling is preferably immediate, achieving the desired structural stabilization / change without the risk of vaporization. Commercially available FLA devices can operate at heating rates up to 100,000°C / s, which melts sulfur and causes it to collapse due to its low viscosity (similar to glycerol at 60°C, 120 mPa). Sulfur wafers tend to melt and collapse, fusing / closing all internal voids and causing total failure. To avoid this, structural support in the form of graphene layers is provided to bond / crosslink the sulfur, and this treatment liquid fills the internal spaces / voids of the sulfur wafer. During this process, simultaneous expansion of liquid / vapor and gas occurs within the porous voids of the sulfur wafer. The treatment solution turns into steam and expands inside the voids along with the water vapor and gas, countering the expansion caused by the photon-induced heating of the sulfur wafer. This instantaneous reaction suppresses the structural collapse of the sulfur voids. A thin conductive layer on the sulfur wafer, including two-dimensional materials such as carbon, graphene / graphene oxide, and / or their derivatives (but not limited to), immediately reacts / crosslinks with the molten / polymeric sulfur. Sulfur radicals with unpaired electrons at both ends of the chain react violently with graphene oxide, reducing it to rGO, also known as deoxidized GO, and forming a crosslinked / covalently / chemically bonded protective layer on its surface called "fishscale." This layer structurally reinforces the sulfur wafer during and after pre-expansion and ensures excellent electronic and ionic conductivity.

[0072] Sulfur pre-expansion is the most advanced method to exploit sulfur's volumetric potential, as summarized in Table 1. The first row represents monolithic 3D bodies formed from aligned nanocrystals of single or one-dimensional / two-dimensional monoclinic sulfur allotropes, which together form polycrystalline, paracrystalline, or glassy crystalline sulfur wafers with hierarchical porosity. The main difference between the single wafers represented here and current slurry-based sulfur cathodes with suitable 3D hosts, such as graphene scaffolds, is the presence or absence of particle-aggregates-clusters (PAC) networks, which are commonly found in both conventional lithium-ion batteries and the latest generation of post-lithium batteries.

[0073] Table 1. Volume expansion of different cathode materials [Table 1]

[0074] The coated electrodes / cathodes thus produced containing pre-expanded sulfur possess a unique combination of internal (closed, inaccessible) porosity and external (open, accessible) porosity, the latter of which can be further occupied by electrolyte, or more preferably, catholyte. Pre-expanded sulfur cathodes are expected to exhibit better conductivity, higher active material utilization, E / S ratios lower than 1.5 mL / g, and the ability to internally interfere with volume fluctuations during cycling without requiring the provision or creation of additional open volume / pores. Pre-expanded, pure and / or doped chalcogenides or mixtures of any two or more, or preferably sulfur-based electrodes, can be used in electrochemical energy storage devices, i.e., secondary rechargeable batteries containing Li, Na, K, Ca, Mg, or Al metals / ions as counter electrodes, or more specifically, high-energy LiS batteries, Na-S batteries, Al-S batteries, Mg-S batteries, etc.

Claims

1. A method for expanding a chalcogenide material, comprising the steps of: a) providing a porous free-standing chalcogenide material-wafer; b) coating the chalcogenide wafer with at least one layer of graphene oxide; c) immersing the coated chalcogenide wafer in a treatment solution; d) subjecting the soaked coated chalcogenide material to photon and / or electron irradiation, thereby increasing the temperature of the chalcogenide material to a range of 320°C to 420°C, more preferably to 365°C, thereby expanding the chalcogenide material; and e) The expanded chalcogenide material is heated to its T ｇ cooling to below the glass transition temperature, in the range of -196 to 4°C, more preferably below -35°C wherein the cooling medium is a process liquid and / or gas.

2. an electrode (e.g., cathode) comprising a chalcogenide material, a) the chalcogenide material is expanded to a state where it exhibits the same density as the corresponding metal chalcogenide; b) the apparent density of the chalcogenide material after expansion is within the range of the true density of the corresponding metal chalcogenide and the chalcogenide itself; c) the internal voids of the chalcogenide material provide buffer volume available for volume compensation during charge / discharge of the battery; d) An electrode wherein the manufacturing process is characterized by interactive co-expansion of the chalcogenide material with processing liquids and / or gases.

3. 3. The electrode of claim 2, An electrode, wherein the surface of the chalcogenide material is covered and / or coated and / or stabilized with a two-dimensional material, preferably a graphene-based material such as graphene oxide, which crosslinks to the chalcogenide material during the expansion process.

4. 4. The electrode according to claim 2 or 3, The chalcogenide material acts as a redox active material, The mass content is 85% or more, and the porous structure exhibits hierarchical porosity. The electrode acts as a buffer volume, with the open pores available for electrolyte / catholyte and the closed pores available for volume compensation.

5. The electrode according to any one of claims 2 to 4, the chalcogenide material is selected from sulfur (S), selenium (Se), and tellurium (Te); In particular, the chalcogenide material is sulfur; More preferably, the chalcogenide material is a sulfur wafer.

6. The electrode according to any one of claims 2 to 5, A specific volume compensation for discharge products is allocated between the open and closed porous sections, The open porosity allows for the transfer of 79% of the sulfur to Li. ２ has the ability to compensate for 0.25 to 100% of all electrochemically driven theoretical volume expansion to S; The closed porous portion compensates for the remaining 0-50% of the total volume change of the discharged metal disulfide product.

7. 6. The electrode of claim 5, The final product in a fully discharged state is Na ２ S, where the volume compensation is partially compensated by a combination of 90% or less of the available closed porosity of the sulfur wafer and 45% or less of the available open porosity of the electrolyte; Theoretical sulfur Na ２ The remaining 22% of the theoretical 157% conversion to S is not compensated, limiting the volume variation of such a cell to 22%, the electrode.

8. 8. The electrode of claim 7 having a limited operating range, The final product of the discharge is Na ２ S ２ , the theoretical 67% volume variation of which is completely compensated by the closed porous portion.

9. A laser-based device for expanding and cooling chalcogenide materials to a state having a density similar to that of metal chalcogenides.

10. 10. The laser-based device of claim 9, wherein the wavelength of the photons is between the range of 430 nm and 100 nm, more preferably 390 nm.

11. A FLA / IPL-based apparatus for expanding and cooling a chalcogenide material to a state where the chalcogenide material has a density similar to that of a metal chalcogenide.

12. 12. A FLA / IPL-based device according to claim 11, wherein the wavelength of the photons is between the range of 800 nm and 170 nm, more preferably within the range of 450 nm to 250 nm.

13. 13. The FLA / IPL based device of claim 12, The FLA / IPL source was 25 J / cm ２ or more, preferably 120 J / cm ２ FLA / IPL based devices that generate high intensity photon fluxes with greater fluence.

14. 10. The laser-based device of claim 9, The laser source is 100 J / cm ２ ~400 J / cm ２ or more preferably in the range of 250 J / cm ２ A laser-based device that produces a high-intensity photon flux with greater fluence.

15. 10. The laser-based device of claim 9, wherein the laser beam is guided through the processing / cooling liquid.

16. 10. An electrode (especially a cathode) comprising an expanded chalcogenide material produced by the method of claim 1.

17. A battery comprising an electrode (especially a cathode) according to claim 16.

18. 20. The battery of claim 17 having an electrolyte to sulfur ratio (E / S) of less than 1.99 ml / g.

19. 10. An apparatus for carrying out the method of claim 1, comprising: a chamber for placing a wafer containing a chalcogenide material (particularly a sulfur-containing wafer); an irradiation source for expanding chalcogenide materials (particularly sulfur) using photons; and The apparatus has a control system that regulates the expansion process.

20. a movable arm that includes means for moving the radiation source (particularly a laser source) and for supplying a flow of liquid to the wafer; and a means for holding the wafer, which has a rotation function and can rotate in a clockwise or counterclockwise direction at a desired speed (preferably 15 to 20 revolutions per minute); 20. The apparatus of claim 19 further comprising:

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