Method for producing copper-rich silicone foam from a mixed phase of at least two components - Patents.com

Abstract

The present invention relates to a method for producing a copper-rich silicon foam from a mixed phase of at least two components, in which a silicon layer structure is deposited on a support substrate. The aim of the present invention is to provide an alternative method using nanoparticles and nanowires, which allows the production of a copper-rich silicon foam that can be preferably used as a high-capacity electrode material in rechargeable batteries. This is achieved in that one layer of the silicon layer structure is made of at least two plies and at least two materials, which have different diffusion constants, and which layer is subjected to a rapid annealing process with controlled energy input, forming cavities with structures of different diameters.

Description

[Technical field]

[0001] The present invention relates to a method for producing copper-rich foamed silicone from a mixed phase of at least two components, in which a silicon ply structure is attached to a supporting substrate.

[0002] The present invention further relates to the use of the method of the present invention for producing high capacity electrode materials in lithium ion batteries, more specifically for silicon anodes and anode materials, and their use in battery cells and lithium ion batteries. [Background technology]

[0003] The aim of the present invention is to form a porous silicon-rich layer that is highly conductive and allows good diffusion of lithium. The inherent porosity within the layer allows for continuous compensation of the volume expansion that occurs when lithium is intercalated, without losing electrical contact with the supporting substrate. Also, a stable and unchanged surface is advantageous when such a layer is used in an electrolyte as an electrode in a battery application.

[0004] The theoretical background is explained below with reference to the Si-Cu-Ni mixed system. The various nickel silicide phases undergo volume changes during their formation (Non-Patent Document 1, Non-Patent Document 2). Silicon-rich NiSi x The volume expansion of the nickel-rich NiSi phase is small. x In the crystalline phase, the volume expansion is even larger. In particular, Ni2Si exhibits a volume expansion up to 200% larger than that of pure crystalline silicon.

[0005] It has been demonstrated that in the copper-nickel-silicon (Cu-Ni-Si) system, nickel silicide is formed first during the annealing process, which is then completely converted to copper silicide. Physically, it is the different formation enthalpies of the different silicides that drive these reactions. If the process time is such that adequate material transport is not possible (not in equilibrium), voids, pores, or cavities are left behind. This results in the formation of foam-like silicide structures. Also, when two or more metals with different diffusion rates are present, an additional effect occurs, called the Kirkendall effect. From Non-Patent Document 3, it is known that cavities in the submicron range, known as Kirkendall voids, form in the intermetallic compounds of solder joints. This observed effect has a negative effect on the adhesion of the solder contacts. If too many Kirkendall voids occur at the interface, the structural adhesion is reduced and the contact is lost.

[0006] In order to appreciate how the method of the present invention can be advantageously used in battery manufacturing, and in particular in lithium ion batteries, a brief description of the construction of these batteries will be provided.

[0007] Batteries are electrochemical energy storage devices, and a distinction is made between primary and secondary batteries.

[0008] A primary battery is an electrochemical power source in which chemical energy is irreversibly converted into electrical energy. Therefore, primary batteries cannot be recharged. Secondary batteries, on the other hand, also called accumulators, are rechargeable electrochemical energy storage devices in which the chemical reactions that occur are reversible, meaning that they can be used repeatedly. When charging, electrical energy is converted into chemical energy, and then when discharging, chemical energy is converted back into electrical energy.

[0009] A battery is a collective term for an array of interconnected cells. A cell is a galvanic unit consisting of two electrodes, an electrolyte, a separator, and a cell housing. Figure 1 shows an exemplary structure and function of a lithium-ion cell during the discharge process. Below, a brief description of the components of a cell is provided.

[0010] Each lithium-ion cell consists of two different electrodes, one that is negatively charged in the charged state and the other that is positively charged in the charged state. During energy release, or discharging, ions move from the negatively charged electrode to the positively charged electrode, so the positively charged electrode is called the cathode and the negatively charged electrode the anode. Each electrode consists of a current conductor (also called a current collector) and an active material applied to it, the active layer. Between the electrodes, firstly, there is an ionically conductive electrolyte that allows the necessary charge exchange, and a separator that ensures the electrical isolation of the electrodes.

[0011] The cathode consists, for example, of a mixed oxide deposited on an aluminum current collector.

[0012] The anode of a lithium-ion cell can consist of copper foil as the current collector and a layer of carbon or silicon as the active material. During the charging process, lithium ions are reduced and intercalated into the graphite or silicon layer.

[0013] In the construction of lithium-ion batteries (LiBs), the battery capacity is usually limited by the cathode capacity, since the cathode provides the lithium atoms for charging and discharging the anode. Examples of typical cathode materials used to date are Li(Ni,Co,Mn)O2 and LiFePO4. The cathode is made of lithium metal oxides that provide the lithium ions that are intercalated during the discharge of the cell, leaving minimal room for capacity expansion.

[0014] The capacity of a battery is determined by the thickness of the active layer (more specifically, the Si layer). In a battery, the electrical conductivity of the active material must be as high as possible. Silicon is a semiconductor and therefore only has a low electrical conductivity, unlike conductive graphite. Therefore, silicon needs to be highly doped or structured to increase its electrical conductivity. The standard method is to encase nanoscale silicon powder in a carbon-containing scaffold structure and fix it to the current collector.

[0015] Challenges that arise when using silicon as an electrode material include the sometimes significant volume changes (volume contraction and expansion) of the host matrix during the intercalation and deintercalation of mobile ionic species (lithium) during charging and discharging of the corresponding energy storage device. The volume change is about 10% for graphite, in contrast to up to 300% for silicon, which is 10 times the theoretical Li 22 In the Si5 phase, this volume expansion is unavoidable at full lithium storage of 3579 mAh / g. When using silicon in battery applications, the change in volume of the electrode material will cause internal stresses, cracks, and crushing of the active material, ultimately leading to a complete loss of electrode capacity.

[0016] To compensate for the volume change, known battery manufacturing processes use carbon or silicon-based nanoparticles and nanowires as anode materials for rechargeable lithium batteries. The main advantage of such nanomaterials, in addition to the increased rate of lithium intercalation and deintercalation, is the surface effect. This can be understood as meaning that a larger surface area increases the contact surface area with the electrolyte and the associated flow of Li+ ions (voids) through the interface, as described in Non-Patent Document 4. Silicon-based nanoparticles and nanowires in particular have a smaller storage capacity of about 3400 mAh / g compared to the maximum possible storage capacity of silicon of 3579 mAh / g, but they show a more stable silicon structure up to a certain size of the Si structure with respect to the volume change of silicon after lithium intercalation, as described in Non-Patent Document 5. The structural limit for a uniform volume change is considered to be 1 μm for amorphous silicon and 100 nm for crystalline silicon.

[0017] Therefore, not only can the volume expansion of the electrode material be accommodated by the free space between the nanostructures, but the reduction in size of the structures also facilitates the phase transformation during alloy formation, resulting in improved performance of the electrode material.

[0018] However, the application of silicon-based nanoparticles and nanowires is very complicated. Si nanostructures are produced by both physical and chemical processes, including ball milling, sputtering deposition, PVD / CVD processes, chemical and electrochemical etching, and reduction of SiO2 (Non-Patent Document 6). In the prior art, the produced nanostructures are then mixed with conductive carbon and binders, and in industrial anode construction, they are attached to a copper current collector by calendaring and drying. The drawback of these processes is that the nanostructures separate from each other during the operation of the battery, resulting in loss of anode capacity. An additional drawback is that the large surface area of ​​the nanostructures consumes a large amount of electrolyte and dries out the battery.

[0019] So far, alternative manufacturing of Si-Cu hollow structures suitable for lithium-ion batteries was only possible by complex furnace processes (Non-Patent Document 7). [Prior art documents] [Non-patent literature]

[0020] [Non-Patent Document 1] Simon, M. et al.: Lateral Extensions to Nanowires for Controlling Nickel Silicidation Kinetics: Improving Contact Uniformity of Nanoelectronic Devices. ACS Appl. Nano Mater. 4, 4371-4378 (2021) [Non-Patent Document 2] Tang, W., Nguyen, B.-M., Chen, R., Dayeh, SA: Solid-state reaction of nickel silicide and germanide contacts to semiconductor nanochannels. Semicond. Sci. Technol. 29, 054004 (2014) [Non-Patent Document 3] Kim, D., Chang, J., Park, J., Pak, JJ: Formation and behavior of Kirkendall voids within intermetallic layers of solder joints. J Mater Sci: Mater Electron 22, 703-716 (2011) [Non-Patent Document 4] MR Zamfir, HT Nguyen, E. Moyen, YH Leeac, D. Pribat: Silicon nanowires for Li-based battery anodes: a review, Journal of Materials Chemistry A (a review), 1, 9566 (2013) [Non-Patent Document 5] M. Green, E. Fielder, B. Scrosati, M. Wachtier, JS Moreno: Structured silicon anodes for lithium battery applications, Electrochem. Solid-State Lett, 6, A75-A79 (2003) [Non-Patent Document 6] Feng, K. et al.: Silicon-Based Anodes for Lithium-Ion Batteries: From Fundamentals to Practical Applications. Small 14, 1702737 (2018) [Non-Patent Document 7] He, Y., Wang, Y., Yu, X., Li, H., Huang, X.: Si-Cu Thin Film Electrode with Kirkendall Voids Structure for Lithium-Ion Batteries. J. Electrochem. Soc. 159, A2076 (2012) Summary of the Invention [Problem to be solved by the invention]

[0021] It is therefore an object of the present invention to provide an alternative to the use of nanoparticles and nanowires, by which copper-rich silicone foams can be produced, which can preferably be used as high-capacity electrode materials in rechargeable batteries. The properties of the layer produced by the process can be selectively modified through adjustment of the process parameters and should be tailored to the respective application, and the process should be as simple, fast and efficient as possible to carry out. [Means for solving the problem]

[0022] This object is achieved by the method according to independent claim 1. In a method for producing copper-rich foamed silicone from an at least two-component mixed phase, in which a silicon ply structure is applied to a support substrate, plies of the silicon ply structure consisting of at least two layers and at least two or more materials, the materials having different diffusion constants, are formed and applied, and the plies are subjected to short cycle annealing with selective input of energy to form cavity structures of various diameters.

[0023] Short cycle annealing is understood to mean in particular flash lamp annealing and / or laser annealing. Flash lamp annealing has a pulse width or annealing time in the range of 0.3-20 ms and a power of 0.3-100 J / cm 2 Laser annealing is performed with pulse energies ranging from 0.1 to 100 J / cm 2 The annealing time is adjusted from 0.01 to 100 ms by the scanning speed of the local heating spot so that an energy density of 1000 s is obtained. The heating gradient achieved in short cycle annealing is less than the 1000 s required for the process. 4 ~10 7 K / s range. Flash lamp annealing uses the visible wavelength range of the spectrum for this purpose, whereas laser annealing uses discrete wavelengths from the infrared (IR) to the ultraviolet (UV) spectrum.

[0024] A ply is understood to mean a layer stack formed from at least two layers. A ply therefore comprises at least two layers. A ply is made up of at least two different materials, for example it is possible to form a ply from two silicon layers and a copper layer, i.e. the ply in this example comprises a Si-Cu-Si layer stack.

[0025] Simply stacking different layers into two or more plies of material after short cycle annealing produces cavities that go beyond the effect described by Kirkendall. Various intermetallic phases with different densities or lattice parameters are formed, sometimes simultaneously, sometimes successively, making it possible to control time-dependent processes by short cycle annealing with process parameters that can be adjusted in a defined way.

[0026] The method of the present invention allows for the formation of a porous silicide-silicon matrix in which amorphous or nanoscale silicon is present along with cavities or pores.

[0027] These fundamental process steps generate a huge range of parameters that can be selectively optimized for the application in which the produced layer will be used. In particular, short cycle annealing offers a decisive advantage due to the selective energy input. It allows the control of diffusion processes in the mixed layer and allows the stabilization of non-equilibrium conditions that are not at equilibrium.

[0028] In one variation of the method of the present invention, plies are deposited that are composed of at least copper and silicon, i.e. Cu-Si, where the deposition of Cu and Si is done layer by layer and short cycle annealing reacts Cu and Si to form a binary mixed phase.

[0029] In another variation of the method of the present invention, plies are deposited that are composed of copper, silicon, and other materials, i.e., Cu-Si-X. The materials are deposited layer by layer, and when three different materials are used, short cycle annealing reacts the materials to form a ternary mixed phase.

[0030] In a further variant of the method of the invention, the other material is nickel (Ni), titanium (Ti), aluminum (Al), tin (Sn), germanium (Ge), lithium (Li), tungsten (W) and / or carbon (C).

[0031] In one variation of the method of the invention, when nickel is also deposited as other material in addition to Cu and Si, the short cycle annealing first produces nickel silicide, which is then completely converted to copper silicide.

[0032] This produces a foam-like silicide structure suitable for use as an active layer in lithium-ion batteries to produce a stable anode for lithium-ion batteries. The size of the cavity structure formed can be controlled by controlling the energy of the flash lamp and / or laser, since the formation of the cavities maintains mechanical contact between the active layer and the substrate. And the cavities reduce the volume expansion of the silicon anode upon lithium intercalation.

[0033] In a further variant of the method of the invention, the short cycle annealing is flash lamp annealing, in which a pulse width in the range of 0.3 to 20 ms and / or a power of 0.3 to 100 J / cm 2 The formation of the cavity structure is controlled by preheating or cooling the support substrate in the range of 4° C. to 200° C. with a pulse energy in the range of 1000 nm to 1500 nm.

[0034] When laser annealing is used as the short-period annealing, the laser annealing is performed by setting the scanning speed of the local heating point and the energy density to be 0.1 to 100 J / cm throughout the annealing time in the range of 0.01 to 100 ms. 2 By setting the temperature range from 0° C. to 400° C. and preheating or cooling in the range of 4° C. to 200° C. during laser annealing, the formation of cavity structures is controlled, thereby producing partially reacted silicon within each ply.

[0035] In the method of the invention, any desired layer stack, i.e. plies composed of metals with different diffusion constants, can be deposited, for example by sputtering or evaporation processes. The layer stack forms a ply. A ply structure is formed from two or more plies. An additional annealing process can be performed quickly and efficiently with a wide range of options by changing the flash / laser pulse energy, the flash / laser pulse time, and / or the pre-heating or cooling of the substrate.

[0036] In one variation of the method of the invention, a plurality of plies are applied to a support substrate of a silicon ply structure, each ply being deposited with an individually adjustable layer thickness. Within a ply, each layer is deposited with an individually adjustable layer thickness. The deposited plies can be repeatedly deposited as further plies using the employed process parameters or different process parameters.

[0037] In another variation of the method of the invention, the silicon ply structure has a stable cavity structure that is formed by removal of previously introduced lithium or during operation of a silicon anode made of electrode material formed by the silicon ply structure through introduction and removal of lithium.

[0038] In a further variant of the method of the invention, the silicon ply structure has stable cavity structures formed with a size and number determined in an autoregulatory manner by the diffusion rate of lithium. In addition to lithium intercalation leaving a cavity structure, the number and size of these structures can be influenced by the charging rate, i.e. the nature of the use. This means more specifically that the charging and discharging rate of the battery, or the operating mode or use of the battery in general. In the literature (C. Heubner, U. Langklotz, A. Michaelis, Theoretical optimization of electrode design parameters of Si based anodes for lithium-ion batteries, J. Energy Storage, Vol. 15, 2018, pp. 181-190), it is shown that the possible diffusion rate depends on the porosity of the silicon anode, which is adjusted in an autoregulatory manner in the method of the invention.

[0039] The introduction of lithium leads to the formation of cavity structures in the mixed phase system. When lithium is removed, stable cavity structures in each ply or in the entire ply structure are irreversibly formed. Other mixed phases are possible in the form of intermediate reactions. A suitable layer stack consisting of Cu-Si(-X) mixed phases expands here during lithium intercalation irreversibly, but in a mechanically stable manner. The high adhesion of the entire ply structure to the support substrate and the use of mixed phases with a heterogeneous structure consisting of silicon embedded in a silicide structure allow stable cavity structures to be formed here. The introduction and removal of lithium can be advantageously performed even during the initial cycles (formation) in the operation of the battery. The cavity structures are able to completely absorb the volume expansion of silicon during lithiation and delithiation. Thus, the cavity structures formed by the entire active layer can achieve a greater than 300% change in volume due to the formation of pure lithium silicide (Li 22In the case of Si5, theoretically, this is possible by 400%). Depending on the amount of lithium absorbed, the expansion of the silicon will always be the same. Physically, this means that the expansion of the volume is equal to the amount of storage. Thus, the cavity structure that will eventually absorb the expansion can be significantly larger than the pure expansion of the silicon. The key is that the cavity structure must be stable. A special feature of the method of the invention is that the cavity structure is produced both during the manufacturing in the flash lamp process and during the "initial" operation of the battery, and remains stable thereafter. This is made possible according to the invention by providing a suitable conductive and expandable scaffold for the mixed phase system. This creates cavities of variable size and number (porosity) within the ply structure. As an example, SEM images of plies of Si-Cu mixed layers after cycling are attached (Figures 4-6), which show that the original 1 μm thick Si layer has become 10 μm thick. High-resolution SEM investigations allowed here the additional measurement of pore sizes with average values ​​of 10 nm and porosities of 7–15%, in addition to macroscopic pores (100 nm–2 μm). Positron annihilation spectroscopy investigations allowed the detection of voids in the range of 0.5–2 nm, depending on the selected process parameters.

[0040] The advantage of the method of the invention in battery applications is that it allows a variable stack structure to adjust the cavity structure without additional complexity. Different material systems can be combined to adjust the number of cavities formed. In the layer structure here, a flat surface with minimal irregularities is favored to form a stable protective layer. The cavities, whose sizes range from nanoscale to microscale size range, ensure a stable layer both during fabrication and during the volume expansion due to lithium intercalation.

[0041] In a further variation of the method of the invention, each ply is subjected to an individual short cycle annealing, which allows the cavity structure of each ply of the silicon ply structure to be individually tailored.

[0042] The use of short cycle flash lamp or laser annealing techniques in the method of the present invention allows for selective control of the energy input to the layer. The formation of Kirkendall cavities is a diffusion-driven process and is regulated by the energy input per unit time.

[0043] The method of the invention makes it possible to selectively use transient intermediate phases, i.e. phases in which the reaction has not proceeded to completion, and short-lived lattice structures, and for this purpose makes it possible to use any desired combination of materials with different diffusion constants to form cavities of different diameters.

[0044] It is therefore advantageous to use the method for producing copper-rich silicon foam according to the invention as defined in claims 1 to 11 for producing high-capacity electrode materials in lithium-ion batteries, more particularly for silicon anodes.

[0045] It would further be advantageous to produce anode materials for electrochemical cells, and more specifically for lithium ion batteries.

[0046] The anode material can be used in a battery cell, which can then be assembled into a battery having at least one battery cell.

[0047] The advantage of the method of the present invention is that the described properties are not produced and achieved by a complex process, but are obtained naturally by selectively using short cycle annealing, which is carried out in a single process step and is highly scalable and therefore extremely cost-effective. Other processes are even more complex, require much more energy than flash lamp annealing, and cannot be applied in a scalable manner.

[0048] The present invention is more particularly described in the following exemplary embodiments. [Brief description of the drawings]

[0049] [Figure 1] 1 illustrates an exemplary structure and function of a lithium-ion cell during a discharge process. [Diagram 2] Schematic illustration of plies formed from the two materials and the formation of copper-rich foamed silicone as a function of the short cycle annealing parameters employed. [Diagram 3] FIG. 1 is a schematic diagram of the method of the present invention in a configuration in which cavity structures are formed by the introduction and removal of lithium. [Figure 4] SEM image of the cavity structure of a Si-ply structure formed from a binary mixture of Cu and Si. [Diagram 5] SEM images of the Si-ply structure of the present invention during formation (initial cycle and intercalation of Li in Si). [Figure 6a] High-resolution SEM image of cycled Si multiple ply anodes. [Figure 6b] Figure 6 a shows the pore size with an average diameter of 10 nm and a porosity of 7–15%. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0050] FIG. 2 shows a schematic diagram of the produced copper-rich foamed silicon, where in the illustrated example, the ply 11 of the silicon ply structure 10 is formed from a three-layer stack composed of the material Si-Cu-Si 12-13-12. Short cycle annealing 14 results in the formation of a porous silicide matrix rich in amorphous silicon, ideally suited as a high capacity electrode material to mitigate the volume expansion of silicon due to lithium intercalation. At the same time, the conductive silicide matrix forms a stable scaffold, ensuring reliable electrical contact with the current collector and enabling continuous operation of the battery. The diffusion rate of Cu in Si is much faster than that of Si in Cu, i.e., D Cu in Si >>D Si in Cu Therefore, a cavity structure can be formed. In thermal equilibrium, the following approximation is satisfied: Cu in Si ≒D voids +D Si in Cu holds true.

[0051] FIG. 3 shows a schematic diagram of the method of the present invention in a configuration in which a cavity structure is formed by the introduction and removal of lithium. When the method of the present invention for producing copper-rich foamed silicon is used to produce a high capacity electrode material in a lithium-ion battery, more specifically for a silicon anode, the produced ply structure 10 expands by a factor of 10 during the initial formation as a result of the introduction of lithium. This volume expansion is maintained during discharge, since a stable cavity structure has been formed. Upon further operation of the battery, lithium can again intercalate within the formed cavity structure.

[0052] Figure 4 shows an SEM image of cavity structures in a Si ply structure 10, which is formed from a binary mixture of Cu and Si. All layers sputtered onto a supporting substrate 15 are visible. The gradual increase in thickness 13 of the Cu layer, which can be individually adjusted during the manufacturing process, is also visible. Intermediate flashes in flash lamp annealing or laser annealing 14 lead (as an example) to diffusion of Cu into the Si and the formation of cavity structures 16. The thicker the Cu layer 13, the larger the cavities.

[0053] Figure 5 shows SEM images of the structure of the Si ply structure of the present invention during formation (initial cycle and intercalation of Li in Si) and stable cavity structure with fine cavities to accommodate the volume expansion of silicon. The scaffold has a high copper content, which ensures a constant high electrical conductivity.

[0054] Figure 6 shows a) a high-resolution image of a multi-ply Si anode after battery operation. A porosity of 15% was measured. The size of the cavities depicted here ranges from 2 nm to 50 nm (Figure 6b). The median size of the depicted cavities, determined by visual assessment, is 10 nm.

[0055] In one embodiment, silicon ply structures with copper and nickel show a significant increase in layer thickness after short cycle annealing that is not solely due to volume expansion caused by crystallization or oxidation (Figure 5). Measurements show structures containing both macroscopic and microscopic cavities up to the nanoscale size range (Figure 6). When used as an electrode material in a battery, the foam structure formed leads to improved battery performance, as it is able to compensate for the volume change caused by the intercalation of lithium in the layers.

[0056] In case of incomplete reaction, (temporary) intermediate phases with lower density or occupying a larger spatial volume may occur. However, at the end of the method of the invention, the final transformation to a denser silicide structure occurs. Due to the short process time, the voids cannot be filled by diffusion of the missing material here, and (microscale / nanoscale) foam structures are formed. These cavity structures can also compensate for the volume expansion of silicon during lithium intercalation. With the method of the invention, a 5-fold increase in layer thickness of the material system has been demonstrated, although with typical lattice expansion and oxide formation, a 2- or 3-fold increase is realistic. The remaining thickness or volume increase is due to the cavity structures that are formed. [Explanation of symbols]

[0057] 1 Lithium-ion battery 2 Anode side current collector 3 SEI (solid electrolyte interface) 4 Electrolytes 5. Separator 6. Conductive Mesophase 7 Cathode, Anode 8 Cathode side current collector 9 Anode, Cathode 10 Silicon ply structure 11 Ply 12 Silicon layer 13 Copper layer 14 Short cycle annealing step 15 Support substrate 16 Hollow structure

Claims

1. 1. A method for producing copper-rich foamed silicone from an at least two-component mixed phase, in which a silicone ply structure (10) is attached to a support substrate (15), comprising: The method includes forming a ply (11) of the silicon ply structure (10) composed of at least two layers (12, 13) and at least two materials, the at least two materials having different diffusion constants, and subjecting the ply (11) to short cycle annealing (14) with selective input of energy to form cavity structures (16) of various diameters.

2. A method according to claim 1, characterized in that said ply (11) is deposited consisting of at least copper (13) and silicon (12), i.e. Cu-Si.

3. 2. A method according to claim 1, characterized in that a ply (11) is deposited which is made up of copper, silicon and other materials, namely Cu-X-Si.

4. 4. The method of claim 3, wherein the other material is nickel (Ni), titanium (Ti), aluminum (Al), tin (Sn), germanium (Ge), lithium (Li), tungsten (W), and / or carbon (C).

5. 5. The method of claim 4, wherein said other material is nickel and said short cycle annealing (14) first produces nickel silicide, which is then completely converted to copper silicide.

6. The short cycle annealing (14) is flash lamp annealing, and in the flash lamp annealing, a pulse width in the range of 0.3 to 20 ms and / or a power of 0.3 to 100 J / cm 2 2. The method of claim 1, wherein the formation of the cavity structure (16) is controlled by pulse energy in the range of 0.5 to 100 Hz and by pre-heating or cooling the support substrate in the range of 4°C to 200°C.

7. The short cycle annealing (14) is laser annealing, and the laser annealing is performed by setting the scanning speed of the local heating point and the energy density to be 0.1 to 100 J / cm throughout the annealing time in the range of 0.01 to 100 ms. ２ 2. The method according to claim 1, wherein the formation of the cavity structure (16) is controlled by setting the temperature in the range of 4° C. to 200° C. and preheating or cooling in the range of 4° C. to 200° C. during the laser annealing.

8. 2. The method of claim 1, wherein a plurality of plies (11) are attached to the support substrate (15) of the silicon ply structure (10), each ply (11) being deposited with an individually adjustable layer thickness.

9. 8. A method according to claim 7, characterized in that each ply (11) is subjected to a separate short cycle annealing (14).

10. 10. The method of claim 1, wherein the silicon ply structure (10) has a stable void structure (16) formed by removal of previously introduced lithium or during operation of a silicon anode made of electrode material formed by the silicon ply structure through introduction and removal of lithium.

11. 2. The method of claim 1, wherein the silicon ply structure (10) has a stable void structure (16) formed in a size and number that is self-regulatingly determined by the diffusion rate of lithium.

12. A method for producing a high-capacity electrode material for a lithium-ion battery, comprising copper-rich foamed silicone produced by the method of any one of claims 1 to 11.

13. An anode material for an electrochemical cell produced by the method of any one of claims 1 to 11.

14. A battery cell comprising the anode material of claim 13.

15. A battery comprising at least one battery cell according to claim 14.

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