Preparation method and application of programmable porous thick electrode based on sacrificial template

Abstract

The invention discloses a preparation method and application of a programmable porous thick electrode based on a sacrificial template, and relates to the technical field of manufacturing of electrochemical energy storage devices. According to the preparation method, programmable construction of pore size, porosity and thickness direction distribution of the porous thick electrode is realized technologically, ion transport behavior and high-rate electrochemical performance of the thick electrode can be remarkably improved on the premise of ensuring relatively high surface loading capacity and overall mechanical integrity, and the capacity retention ratio and the thickness utilization rate of the thick electrode under high current density are improved.

Description

Technical Field

[0001] This invention relates to the field of electrochemical energy storage device manufacturing technology, specifically to a method for preparing a programmable porous thick electrode based on a sacrificial template and its application. Background Technology

[0002] With the rapid development of electric vehicles and large-scale energy storage systems, the market demand for energy storage devices with high energy density is increasing. For energy storage devices based on electrode materials, increasing the electrode thickness, i.e., increasing the areal loading of active material, is a direct and effective technical path to improve the overall energy density of the device under limited volume and mass constraints. This strategy can significantly reduce the mass and volume ratio of inactive components such as current collectors and separators in the device, thereby improving the energy output level of the device.

[0003] However, existing thick electrodes are typically prepared using traditional processes such as slurry coating and roll forming. As electrode thickness increases, especially when it exceeds 100 μm or even approaches or reaches 500 μm, the ion transport kinetics within the electrode become increasingly problematic. On the one hand, the electrolyte struggles to effectively and promptly penetrate the deep layers of the electrode; on the other hand, the diffusion path required for ions to diffuse through the tortuous and circuitous channels within the electrode increases significantly, leading to a sharp rise in diffusion resistance. This can easily create a "dead zone" near the current collector, making it difficult for the active material in this region to effectively participate in the electrochemical reaction. Consequently, the capacity retention of thick electrodes is significantly reduced under high-rate conditions.

[0004] To improve the transport behavior inside thick electrodes, various methods have been proposed in the prior art, such as introducing porous structures or employing three-dimensional current collectors. For example, this can be achieved by incorporating removable pore-forming agents, preparing porous carbon materials using salt template methods or freeze-drying methods, or utilizing three-dimensional current collectors to shorten the transport path of ions and electrons. However, the above-mentioned technical solutions still have the following shortcomings: (1) Pore structure is uncontrollable. Pores formed by methods such as freeze drying and foaming are mostly randomly generated, with a wide range of pore size distribution and irregular morphology, making it difficult to achieve precise design and control of pore size, porosity and their spatial distribution; (2) Poor process compatibility. Some methods rely on long post-processing (such as acid etching to remove templates) or special equipment, and the process flow is complex. It is difficult to achieve good compatibility with existing mature industrial production processes such as roll-to-roll slurry coating and roll pressing, which is not conducive to large-scale and continuous preparation. (3) High risk of structural collapse. During high-temperature carbonization or template removal, as the pore-forming agent decomposes or dissolves, the carbon skeleton is prone to significant volume shrinkage or local collapse, leading to pore closure or decreased connectivity, making it difficult to simultaneously maintain high porosity and structural integrity.

[0005] Therefore, there is still an urgent need for a method to prepare thick electrodes that is simple to process, allows for precise control of pore size and porosity, and ensures the integrity of the carbon framework structure, so as to significantly improve its ion transport performance and high-rate electrochemical performance while increasing electrode thickness and areal loading. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies, such as limited ion transport, uncontrollable pore structure, and difficulty in balancing high areal loading and high rate performance, this invention provides a method for preparing a programmable porous thick electrode based on a sacrificial template. The resulting thick electrode maintains high mechanical stability and areal loading while possessing a designable pore structure and excellent ion transport capability.

[0007] The technical problem to be solved by this invention is achieved by the following technical solution: One objective of this invention is to provide a method for fabricating a programmable porous thick electrode based on a sacrificial template, the method comprising the following steps: (1) Mix the carbon precursor, template agent and solvent evenly to obtain a slurry; (2) The slurry is coated on the surface of the current collector, and the solvent is removed by drying to form a carbon precursor / template agent composite film on the current collector; (3) Carbonize the composite film to form a porous carbon electrode layer on the current collector, thus obtaining a porous thick electrode.

[0008] Furthermore, the carbon precursor is selected from one or more of aromatic polymers or carbonizable resins such as phenolic resin, polyethersulfone, polyimide, polyamic acid, polyacrylonitrile, epoxy resin, lignin, and asphalt.

[0009] Furthermore, the template agent is selected from one or more of the following materials: polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polystyrene, urea-formaldehyde resin, ammonium chloride, ammonium bicarbonate, calcium carbonate, etc., which can generate gas through thermal decomposition or be removed by solvent cleaning.

[0010] Furthermore, the solvent is selected from one or more polar organic solvents such as N-methylpyrrolidone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), and dimethyl sulfoxide (DMSO).

[0011] Furthermore, the template agent has a particle size of 0.1~200 μm.

[0012] Furthermore, the amount of the template agent is 1 to 80 wt% of the carbon precursor.

[0013] This invention achieves programmable structural control of electrode pore size, porosity, and channel density by selecting the particle size of the template agent and adjusting the mass ratio of the template agent to the carbon precursor.

[0014] Further, the heating temperature is 50~400℃, and the time is 0.5~24 h. The heating temperature is determined according to the glass transition temperature or imidization reaction temperature of the carbon precursor to ensure that the film layer does not undergo macroscopic flow or collapse during the carbonization process in step (3). This invention removes the solvent by heating and induces partial crosslinking or imidization reaction of the carbon precursor, thereby locking the spatial distribution of the template agent in the film layer and obtaining a film with dimensional stability.

[0015] Furthermore, the carbonization treatment includes, but is not limited to, one or more of laser-induced carbonization, flash Joule heat treatment, and high-temperature carbonization in a tube furnace. Through carbonization, the carbon precursor undergoes pyrolysis to transform into a conductive carbon framework. Simultaneously, the template agent is decomposed, vaporized, or sublimated in situ using thermal energy, thereby leaving a pore structure in the conductive carbon framework corresponding to the geometric characteristics of the template agent.

[0016] Furthermore, the light source for laser-induced carbonization is one or more of a laser beam, an electron beam, and an ion beam. By controlling the laser power, scanning speed, and pulse frequency, the local temperature is instantaneously raised to 300~3000℃, simultaneously achieving the graphitization transformation of the precursor and the vaporization removal of the template agent.

[0017] Furthermore, the coating method includes, but is not limited to, one or more of the following: self-leveling method, spin coating method, wire rod coating method, scraping coating method, mold casting method, and slot extrusion coating method.

[0018] Furthermore, the thickness of the single-layer dry film of the film is 10~2000 μm.

[0019] Furthermore, the template agent undergoes surface modification treatment before use to improve its dispersion stability in the slurry and prevent agglomeration. Even further, the surface modification treatment includes one or more of the following: adsorption modification using dispersants or surfactants, introduction modification using polar functional groups, and polymer coating modification.

[0020] Furthermore, the preparation method also includes a step of increasing the electrode thickness by stacking carbon precursor / templator composite films or porous carbon electrode layers layer by layer. That is, repeating steps (1)-(2) to stack carbon precursor / templator composite films layer by layer on the current collector and then carbonizing them in one step to obtain a porous thick electrode, or repeating steps (1)-(3) to stack porous carbon electrode layers layer by layer on the current collector through stepwise carbonization to obtain a porous thick electrode. In different repetition cycles, the particle size and / or amount of template agent can be the same or different, thereby constructing a pore network structure with uniform distribution, disordered distribution or specific functional partitions in the electrode thickness direction.

[0021] Furthermore, the areal loading of the thick electrode is 3~50 mg / cm². 2 .

[0022] The second objective of this invention is to provide the application of the method for preparing the programmable porous thick electrode based on the sacrificial template in the preparation of thick electrodes for supercapacitors, lithium-ion capacitors, lithium-ion batteries or sodium-ion batteries.

[0023] This invention introduces a template agent with specific geometric characteristics into a carbon precursor system. By controlling the rheological properties of the slurry, the template agent is uniformly dispersed and stably suspended during film formation. Subsequently, heating is used to "lock" the spatial distribution of the template. Then, by utilizing the difference in pyrolysis kinetics between the carbon precursor and the template agent during carbonization, "in-situ pore formation" and "carbon skeleton forming" are carried out in a synchronous or sequential manner, thereby constructing a porous structure inside the thick electrode in which the pore size, porosity, and spatial distribution can be designed.

[0024] The technical solution adopted in this invention has a high degree of "programmability", specifically reflected in: (1) Programmable pore size: By selecting template agents with particle size of 0.1~200 μm, the size of the pores inside the carbonized electrode can be directly controlled, realizing cross-scale pore size design from micropores, mesopores to macropores, to adapt to the needs of different energy storage systems for contrast surface area and ion transport path. (2) Density programmable: By adjusting the doping ratio of the template agent (1~80wt%), the overall porosity and channel density of the electrode can be controlled approximately linearly, achieving continuous adjustment from dense structure to high-flux channel structure, thereby achieving a balance between energy storage performance and mechanical strength; (3) Depth programmable: By adopting a combination of processes such as layer-by-layer coating, step-by-step carbonization or overall carbonization, specific pore structures can be introduced at any predetermined position in the thickness direction, and a complex pore network with layered, gradient or regionally selective channel distribution can be constructed in three-dimensional space, so as to realize the fine design and regional control of the ion transport path inside the thick electrode.

[0025] In summary, this invention achieves programmable construction of porous thick electrodes in terms of pore size, porosity, and thickness direction distribution through synergistic control of template particle size, doping ratio, and interlayer distribution. This significantly improves the ion transport behavior and high-rate electrochemical performance of thick electrodes while ensuring high areal loading and overall mechanical integrity, thereby enhancing the capacity retention and thickness utilization of thick electrodes at high current densities.

[0026] The beneficial effects of this invention are as follows: Compared with existing random hole formation or traditional dense thick electrode preparation processes, the preparation method provided by this invention has a simple process route, controllable parameters, and is easily compatible with existing roll-to-roll coating and heat treatment processes. It can realize the integrated and precise design and large-scale preparation of thick electrode structure and performance. At the same time, the preparation method provided by this invention can not only be used as a specific thick electrode preparation process, but also as a general electrode structure design and manufacturing platform, applicable to different material systems and performance requirements. It can achieve customization of the internal microstructure of the electrode through simple parameter adjustment, and has good industrial application prospects. Attached Figure Description

[0027] Figure 1 The image shows a surface scanning electron microscope (SEM) image of the thick electrode prepared in Example 1. Figure 2 Here is a high-magnification SEM image of the surface of the thick electrode prepared in Example 1; Figure 3 A cross-sectional SEM image of the thick electrode prepared in Example 1; Figure 4 Here is a surface SEM image of the thick electrode prepared in Example 2; Figure 5 Here is a surface SEM image of the thick electrode prepared in Example 3; Figure 6 Here is a surface SEM image of the thick electrode prepared in Example 4; Figure 7 SEM image of the surface of the thick electrode prepared in Comparative Example 1; Figure 8 The constant current charge-discharge (GCD) curves of the three-electrode system using the thick electrode prepared in Example 1 as the working electrode at different current densities are shown. Figure 9 The GCD curves of the three-electrode system using the thick electrode prepared in Example 2 as the working electrode are shown at different current densities. Figure 10 The GCD curves of the three-electrode system using the thick electrode prepared in Comparative Example 1 as the working electrode are shown at different current densities. Figure 11 The Nyquist electrochemical impedance spectroscopy (EIS) diagrams are shown for three-electrode systems using thick electrodes prepared in Examples 1, 2, and Comparative Example 1 as working electrodes. Detailed Implementation

[0028] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific embodiments and illustrations.

[0029] I. Rheological matching of precursor and template In this invention, when preparing the film solution, not only the solubility of the precursor in the solvent must be considered, but also the rheological behavior of the slurry system must be comprehensively considered to ensure the uniform dispersion and stable suspension of the template agent before and after coating.

[0030] This invention preferably uses polyethersulfone (PES), polyimide (PI), or phenolic resin as carbon precursors. These polymeric materials have high carbon residue and good film-forming properties, making them suitable as precursors for laser-induced graphene (LIG) or other porous carbon frameworks. For example, PES has good solubility in N-methylpyrrolidone (NMP), and its molecular chain rigidity is moderate, enabling it to effectively suspend template agents with larger particle sizes under suitable viscosity conditions.

[0031] To prevent the template agent from settling before coating, this invention regulates the solution viscosity and thixotropy by adjusting the precursor concentration, solvent ratio, and / or introducing thixotropic additives. Studies have shown that when the PES mass fraction is controlled at 20-30 wt%, the slurry exhibits significant non-Newtonian fluid characteristics, possessing a high apparent viscosity under static conditions. It can stably suspend PET particles with a diameter of 50-100 μm for extended periods, thereby ensuring the uniform distribution of pores within the subsequently formed electrode in both thickness and area directions.

[0032] II. The crucial role of heating in preserving structural fidelity If high-temperature carbonization is performed directly after coating, the wet film still contains a large amount of solvent. Rapid solvent evaporation and rapid shrinkage of the precursor can easily lead to film warping, cracking, or even powdering, making it difficult to obtain a structurally complete thick electrode. To solve this problem, this invention heats the wet film formed after slurry coating at 50-400°C to achieve slow solvent removal and film curing. For polyamic acid (PAA) precursors, an imidization reaction occurs at a heating temperature of 200-300°C, generating polyimide (PI) with a dense segmental structure. PI has a high glass transition temperature and thermal stability (Tg is usually greater than 300°C). In this invention, it is equivalent to constructing a rigid "cage-like skeleton" that effectively locks and encapsulates the internally dispersed template agent. When the temperature continues to rise to the template decomposition temperature or even higher, the precursors such as PI will not show significant melting or flow, effectively resisting the local expansion pressure generated during the vaporization of the template agent, thereby avoiding the collapse of the overall skeleton or pore distortion, and achieving high-fidelity replication of the template geometry.

[0033] III. Carbonization Kinetics and In-situ Pore Formation This invention utilizes the significant differences in the pyrolysis behavior of carbon precursors and template agents under energy beam irradiation or high-temperature environments to achieve synergistic regulation of in-situ pore formation and carbon framework formation.

[0034] Taking laser-induced carbonization as an example, a CO2 laser can be used to pattern the thin film. In the localized area of ​​the laser beam, the temperature can rise to 2000℃ or even higher in a very short time. Under these extreme heating rates and high temperatures, polymeric templates such as PET or PMMA undergo rapid depolymerization and vaporization, and the generated gas expands outward along the path of least resistance. At the same time, the carbon precursor undergoes dehydrogenation, deoxygenation, and desulfurization reactions and rearranges to form graphitized carbon or graphene sheet structures.

[0035] In this invention, the instantaneous gas pressure generated by the vaporization of the template agent applies a swelling force locally to the carbon skeleton, which is still in a softened or semi-crosslinked state, facilitating the peeling and expansion between layers. Simultaneously, it forms through-holes or semi-through-holes in situ at the template location, thereby constructing a porous carbon structure with multi-level pore sizes (a combination of micropores / mesopores / macropores) and a three-dimensional interconnected network. By rationally selecting the type, particle size distribution, and content of the template agent, the rate and intensity of the in-situ pore-forming process can be controlled, further enabling the "programmable" design of pore size, porosity, and their spatial distribution.

[0036] IV. Multi-layer programmable stack The preparation method provided by this invention can also construct multilayer structures layer by layer on the same current collector, thereby achieving the fabrication of ultra-thick porous electrodes with a thickness greater than 500 μm. In a specific embodiment, a slurry containing a carbon precursor and a template agent is first coated onto the current collector, and then cured and carbonized to form a first porous carbon framework; subsequently, a slurry containing a carbon precursor and a template agent is coated onto it, and after curing and carbonization, a second porous carbon framework is formed, and so on to complete the multilayer stacking. The carbon precursor and template agent used to prepare each porous carbon framework layer can be the same or different.

[0037] In the case of laser-induced carbonization, the inventors discovered that when a laser scan is performed on the upper precursor layer that is not yet fully carbonized or has just completed solidification, some of the laser energy penetrates to the surface of the underlying carbonized porous carbon skeleton. This triggers further rearrangement and local "re-sintering" of the carbon skeleton at the interface, thereby achieving a tight fusion between the newly generated carbon material and the underlying carbon skeleton at the atomic or micrometer scale. This process significantly reduces the contact resistance between layers, which is beneficial for constructing a thick electrode structure with good overall conductivity.

[0038] This invention, through differentiated design of the particle size, doping amount, and distribution position of the template agent in different layers, can construct gradient pore structures, segmented channel structures, or integrated structures of "functional layer + support layer" in the thickness direction, thereby achieving comprehensive optimization of the mechanical strength, areal loading, and ion / electron transport performance of thick electrodes.

[0039] The technical solution of the present invention will be further described below through specific embodiments. However, those skilled in the art will understand that these embodiments are only used to illustrate the present invention and should not be construed as limiting the scope of protection of the present invention.

[0040] Example 1 (1) At room temperature, weigh 4 g of PES powder and add it to 16 mL of NMP. Stir at 800 r / min for 5 h, then add 0.2 g of PET particles (average particle size of 100 μm) and continue stirring for 2 h to obtain slurry.

[0041] (2) The above slurry was uniformly coated onto the copper foil current collector (thickness of 50 μm) by spin coating, dried in an oven at 80℃ for 5 h, and then transferred to 200℃ for 2 h to obtain a film.

[0042] (3) The above film was exposed to a CO2 laser beam for laser-induced carbonization treatment. The laser power was set to 8W and the scanning speed was 100 mm / s to obtain the first porous LIG electrode layer.

[0043] (4) Repeat steps (1) to (3) 8 times on the surface of the first porous LIG electrode layer to finally form a nine-layer stacked porous LIG thick electrode on the copper foil current collector.

[0044] Measurements showed that the total thickness of the thick electrode prepared in this embodiment was 500 μm, corresponding to an active material areal loading of 9.39 mg / cm². The thick electrode consists of multiple repeatable porous layers along its thickness direction. The pore size is precisely determined by the PET template particle size, and the porosity and channel density are controlled by the amount of template added. The overall electrode possesses both high areal loading and excellent ion transport channels, providing a structural basis for subsequent device assembly and electrochemical performance testing.

[0045] The morphology of the thick electrode prepared in Example 1 was observed using a scanning electron microscope, and the results are as follows: Figures 1-3 As shown. From Figures 1-3 It can be seen that the thick electrode prepared in Example 1 has a large pore structure with an average pore size of 100 μm that can be clearly observed on both the surface and cross-section, and the pores are interconnected along the thickness direction. This proves that the sacrificial template pore-forming process can form a continuous large-size channel inside the thick electrode.

[0046] Example 2 The preparation method of the thick electrode in this embodiment is the same as that in Example 1, except that the average particle size of the template agent PET is adjusted from 100 μm to 50 μm to prepare a multilayer programmable porous LIG thick electrode with medium pore size channels.

[0047] The morphology of the thick electrode prepared in Example 2 was observed using a scanning electron microscope, and the results are as follows: Figure 4 As shown. From Figure 4 It can be seen that the thick electrode prepared in Example 2 has a uniformly distributed mesoporous channel structure with an average pore size of 50 μm, indicating that using PET with a smaller particle size as a template agent can also construct a through-hole porous network inside the thick electrode.

[0048] Example 3 The preparation method of the thick electrode in this embodiment is the same as in Example 1, except that the template agent is replaced by PMMA instead of PET, and the average particle size is 100 μm.

[0049] The morphology of the thick electrode prepared in Example 3 was observed using a scanning electron microscope, and the results are as follows: Figure 5 As shown. From Figure 5 As can be seen, a macroporous structure with an average pore size of 100 μm can be clearly observed on the surface of the thick electrode prepared in Example 3.

[0050] Example 4 The method for preparing the thick electrode in this embodiment is the same as in Embodiment 3, except that the precursor is replaced by PI instead of PES.

[0051] The morphology of the thick electrode prepared in Example 4 was observed using a scanning electron microscope, and the results are as follows: Figure 6 As shown. From Figure 6 As can be seen, a macroporous structure with an average pore size of 100 μm can be clearly observed on the surface of the thick electrode prepared in Example 4.

[0052] Comparative Example 1 The preparation method of the medium-thick electrode in this comparative example is the same as that in Example 1, except that a template agent is not added during slurry preparation.

[0053] The morphology of the thick electrode prepared in Comparative Example 1 was observed using a scanning electron microscope, and the results are as follows: Figure 7 As shown. From Figure 7 It can be seen that the surface of the thick electrode prepared in Comparative Example 1 is a dense pore with no obvious micron channels.

[0054] Electrochemical performance tests were performed on the thick electrodes prepared in Examples 1, 2, and Comparative Example 1. The thick electrodes were used as working electrodes, platinum sheets as counter electrodes, and Ag / AgCl as reference electrodes. Cyclic voltammetry, constant current charge-discharge, and electrochemical impedance spectroscopy were conducted in 1 mol / L dilute sulfuric acid within a potential window of -0.2 to 0.8 V. The results are as follows: Figures 8-11 As shown.

[0055] from Figure 8 It can be seen that at a current density of 0.5 mA / cm2 Under the given conditions, the areal capacitance of the three-electrode system using the thick electrode prepared in Example 1 as the working electrode was 124 mF / cm²; when the current density was increased to 10 mA / cm², the capacitance was further increased. 2 At that time, its area-to-capacitance retention rate can still reach 79.8%, indicating that the thick electrode still has high capacity retention capability and excellent rate performance under high rate conditions.

[0056] from Figure 9 It can be seen that at a current density of 10 mA / cm 2 Under high-rate conditions, the areal capacitance retention rate of the three-electrode system using the thick electrode prepared in Example 2 as the working electrode was 59.7%, which was 20.1% lower than that in Example 1. This indicates that in the ultra-thick electrode system, under the premise of ensuring structural integrity, larger channels are more conducive to rapid macroscopic replenishment of electrolyte and ion transport in the thickness direction, thereby helping to obtain better rate performance at high current densities.

[0057] from Figure 10 It can be seen that at a current density of 0.5 mA / cm 2 Under the given conditions, the areal capacitance of the three-electrode system using the thick electrode prepared in Comparative Example 1 as the working electrode was 201.6 mF / cm²; when the current density was increased to 10 mA / cm², the capacitance was further improved. 2 At that time, its area specific capacitance retention rate was only 34.7%, which indicates that without the introduction of sacrificial templates to construct programmable channels, the thick electrode prepared in Comparative Example 1 is basically densely packed inside and lacks a through-hole distribution. The ion transport path in the thickness direction is long and tortuous, and the deep active material is difficult to be fully utilized under high current density, thus severely limiting the rate performance of the thick electrode.

[0058] from Figure 11It can be seen that the EIS Nyquist curves of the thick electrodes prepared in Examples 1, 2, and Comparative Example 1 all exhibit small series resistance Rs in the high-frequency region, indicating that their solution resistance and electrode / current collector contact resistance are similar. However, there are significant differences in the slope and diffusion tail length in the low-frequency region. Among them, the curve of Example 1 is closest to the imaginary axis, with the largest slope and shortest diffusion tail in the low-frequency region; Example 2 is in the middle; and the curve of Comparative Example 1 deviates from the imaginary axis the farthest, with the smallest slope and significantly elongated diffusion tail in the low-frequency region. This indicates that the thick electrode with 100 μm channels prepared in Example 1 has the lowest ion diffusion impedance in the thickness direction, followed by the thick electrode with 50 μm channels prepared in Example 2, while the internal ion transport of the thick electrode prepared in Comparative Example 1, which did not introduce a sacrificial template for pore formation, is the most restricted. Therefore, this invention significantly reduces the ion diffusion impedance in the thickness direction by constructing a programmable channel structure in the thick electrode, thereby improving the utilization rate and rate performance of the effective active material under high current density conditions.

[0059] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for fabricating a programmable porous thick electrode based on a sacrificial template, characterized in that, The preparation method includes the following steps: (1) Mix the carbon precursor, template agent and solvent evenly to obtain a slurry; (2) The slurry is coated on the surface of the current collector, and the solvent is removed by drying to form a carbon precursor / template agent composite film on the current collector; (3) Carbonize the composite film to form a porous carbon electrode layer on the current collector, thus obtaining a porous thick electrode.

2. The method for fabricating a programmable porous thick electrode based on a sacrificial template according to claim 1, characterized in that: The carbon precursor is selected from one or more of phenolic resin, polyethersulfone, polyimide, polyamic acid, polyacrylonitrile, epoxy resin, lignin, and pitch; Preferably, the solvent is selected from one or more of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide.

3. The method for fabricating a programmable porous thick electrode based on a sacrificial template according to claim 1, characterized in that: The template agent is selected from one or more of polyethylene terephthalate, polymethyl methacrylate, polystyrene, urea-formaldehyde resin, ammonium chloride, ammonium bicarbonate, and calcium carbonate. Preferably, the template agent has a particle size of 0.1~200 μm; Preferably, the amount of the template agent is 1 to 80 wt% of the carbon precursor.

4. The method for fabricating a programmable porous thick electrode based on a sacrificial template according to claim 1, characterized in that: The heating temperature is 50~400℃, and the time is 0.5~24 h.

5. The method for fabricating a programmable porous thick electrode based on a sacrificial template according to claim 1, characterized in that: The carbonization treatment is selected from one or more of laser-induced carbonization, flash Joule heat treatment, and high-temperature carbonization in a tube furnace. Preferably, the light source for laser-induced carbonization is one or more of a laser beam, an electron beam, and an ion beam.

6. The method for fabricating a programmable porous thick electrode based on a sacrificial template according to claim 1, characterized in that: The coating method is selected from one or more of the following: self-leveling method, spin coating method, wire rod coating method, scraping coating method, mold casting method, and slot extrusion coating method. Preferably, the thickness of the single-layer dry film of the film is 10~2000 μm.

7. The method for fabricating a programmable porous thick electrode based on a sacrificial template according to claim 1, characterized in that: The template agent undergoes surface modification treatment before use; Preferably, the surface modification treatment includes one or more of the following: adsorption modification with dispersants or surfactants, modification by introducing polar functional groups, and polymer coating modification.

8. The method for fabricating a programmable porous thick electrode based on a sacrificial template according to claim 1, characterized in that: The preparation method further includes the step of increasing the electrode thickness by stacking carbon precursor / template agent composite films or porous carbon electrode layers layer by layer, that is, repeating steps (1)-(2) to stack carbon precursor / template agent composite films layer by layer on the current collector and then carbonizing them in one step to obtain a porous thick electrode, or repeating steps (1)-(3) to stack porous carbon electrode layers layer by layer on the current collector through stepwise carbonization to obtain a porous thick electrode.

9. The method for fabricating a programmable porous thick electrode based on a sacrificial template according to claim 1, characterized in that: The areal loading of the thick electrode is 3~50 mg / cm². 2 .

10. The application of the method for preparing a programmable porous thick electrode based on a sacrificial template as described in any one of claims 1 to 9 in the preparation of thick electrodes for supercapacitors, lithium-ion capacitors, lithium-ion batteries or sodium-ion batteries.

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