High-surface-density pole piece and preparation method thereof, battery and power-related equipment

Abstract

The invention provides a high-surface-density pole piece, a preparation method of the high-surface-density pole piece, a battery and power-related equipment, and relates to the technical field of lithium batteries. The preparation method of the high-surface-density pole piece comprises the following steps: preparing a pretreated positive plate; laying metal gallium particles on the surface of the pretreated positive plate to form a composite pole plate with a metal gallium template film; and carrying out rolling treatment on the composite pole piece, and carrying out high-temperature heat treatment on the composite pole piece subjected to rolling treatment to remove the metal gallium so as to obtain the high-surface-density pole piece. Through a hard template method and the phase change characteristic of metal gallium, stable maintenance of a pore structure and efficient pore forming are achieved in the pole piece preparation process, meanwhile, the production cost is reduced, the resource utilization rate is increased, and an efficient, economical and environment-friendly technical path is provided for preparation of the high-surface-density pole piece.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium batteries, and more particularly, to a high areal density electrode sheet, a preparation method thereof, a battery, and an electricity-related device. Background Art

[0002] In the context of today's energy transformation and sustainable development, the rise of new energy technologies has become the focus of global attention. As an important support in the new energy field, the performance of battery technology directly determines the wide application and efficiency of new energy. One of the core components of a battery is the electrode sheet, and its pore structure has a crucial impact on key indicators such as the charge-discharge performance, energy density, and cycle life of the battery. Therefore, in-depth research on the optimization technology of the electrode sheet pore structure has profound strategic significance for promoting the progress of battery technology.

[0003] Currently, the commonly used electrode sheet pore-forming technology in the industry is the soft template method. This method uses a template to form a pore structure in the early stage of electrode sheet manufacturing, and then removes the template before the rolling process. However, in the actual battery manufacturing process, this technology has obvious limitations. During the rolling process, the electrode sheet is subjected to a large pressure, and the pore structure originally formed by the template will collapse due to the pressure. This results in a reduction in the number of pores and the porosity of the electrode sheet, and further causes the performance of the battery to not reach the ideal state.

[0004] In addition, it is difficult to ensure the uniformity of the pores in the electrode sheet of the existing technology. Due to the complexity of the template removal process and the subsequent rolling process, the pore size distribution is often uneven, which further affects the ion transport efficiency inside the battery and the uniformity of the electrode reaction. Problems such as low porosity and uneven pore size distribution make the battery prone to polarization during high-rate charge and discharge, reducing the energy density and cycle stability of the battery. These problems not only limit the improvement of battery performance but also restrict the further development of new energy technologies to a certain extent.

[0005] In summary, the existing electrode sheet pore-forming technologies have significant defects in terms of porosity, pore size distribution uniformity, and adaptability to subsequent processes. These defects prevent the full performance of the battery from being exerted, especially in application scenarios with high energy density and high power output. Therefore, developing a new electrode sheet pore-forming technology that can effectively solve these problems is of great practical significance for improving battery performance and promoting the wide application of new energy technologies.

[0006] In view of this, the present invention is specifically proposed. Summary of the Invention

[0007] The object of the present invention is to provide a method for preparing a high areal density electrode sheet, a high areal density electrode sheet, a battery, and an electricity-related device. Through the hard template method and the phase change characteristics of gallium metal, the method for preparing the high areal density electrode sheet realizes the stable retention of the pore structure and efficient pore formation during the preparation process of the electrode sheet, while reducing the production cost and improving the resource utilization rate, providing an efficient, economical, and environmentally friendly technical path for the preparation of the high areal density electrode sheet.

[0008] In order to achieve the above object of the present invention, the following technical solutions are specifically adopted:

[0009] In the first aspect, the present invention provides a method for preparing a high areal density electrode sheet, including:

[0010] S1, preparing a pretreated positive electrode sheet;

[0011] S2, laying gallium metal particles on the surface of the pretreated positive electrode sheet to form a composite electrode sheet provided with a gallium metal template film;

[0012] S3, performing rolling treatment on the composite electrode sheet, and subjecting the rolled composite electrode sheet to high-temperature heat treatment to remove gallium metal, thereby obtaining a high areal density electrode sheet.

[0013] In an optional embodiment, the areal density of the gallium metal particles is 1 g / m 2 ~10 g / m 2 .

[0014] In an optional embodiment, step S2, laying gallium metal particles on the surface of the pretreated positive electrode sheet to form a composite electrode sheet provided with a gallium metal template film, includes:

[0015] Placing the pretreated positive electrode sheet in an oven, placing the gallium metal particles on the surface of the pretreated positive electrode sheet, and controlling the heat preservation time to be 6 hours to 12 hours.

[0016] In an optional embodiment, during the rolling treatment, the ambient temperature is 10°C to 20°C.

[0017] In an optional embodiment, during the rolling treatment, the ambient humidity is 10%RH to 30%RH.

[0018] In an optional embodiment, subjecting the rolled composite electrode sheet to high-temperature heat treatment to remove gallium metal, thereby obtaining a high areal density electrode sheet, includes:

[0019] Place the composite electrode sheet after roll pressing in an oven under vacuum conditions; and, the placement method of the composite electrode sheet after roll pressing is vertical placement, and a collection container is placed at the lower end of the composite electrode sheet so that the liquefied gallium metal can flow out of the composite electrode sheet by gravity and flow into the collection container.

[0020] In an optional embodiment, the temperature of the oven under vacuum conditions is 90°C to 100°C.

[0021] In a second aspect, the present invention provides a high areal density electrode sheet, which is prepared by the preparation method of the high areal density electrode sheet according to any one of the foregoing embodiments.

[0022] In a third aspect, the present invention provides a battery, including the high areal density electrode sheet according to the foregoing embodiment.

[0023] In a fourth aspect, the present invention provides an electricity-related device, including the battery according to the foregoing embodiment.

[0024] By adopting the hard template method, the present invention utilizes the melting-solidification phase change process of gallium metal to create pores inside the electrode sheet, thereby effectively improving the performance of the electrode sheet. During the preparation process, gallium metal particles are laid on the surface of the pretreated positive electrode sheet to form a composite electrode sheet. Since gallium metal will not disappear due to extrusion during the roll pressing process, its hard template characteristics can ensure that the pore-forming structure is maintained under pressure, thus solving the problem of pore collapse and weakened pore-forming effect in the traditional soft template method during the roll pressing process. Through subsequent high-temperature heat treatment, gallium metal undergoes a phase change, transforming from a solid to a liquid and discharging from the electrode sheet, finally leaving a rich pore structure inside the electrode sheet, achieving the technical goal of creating pores in the electrode sheet.

[0025] In addition, the present invention selects gallium metal as a templating agent, and its phase change process is a physical process with the characteristic of being reusable. After the electrode sheet is prepared, gallium metal can be recycled and reprocessed and then put back into use. This characteristic not only improves the resource utilization rate but also significantly reduces the production preparation cost, making the manufacturing process of the electrode sheet more economical and efficient. At the same time, the physical phase change process of gallium metal avoids the problem of impurity residues that may be brought by chemical reactions, further improving the purity and performance stability of the electrode sheet.

[0026] In summary, through the hard template method and the phase change characteristics of gallium metal, the present invention realizes the stable maintenance of the pore structure and efficient pore creation during the preparation process of the electrode sheet, while reducing the production cost and improving the resource utilization rate, providing an efficient, economical and environmentally friendly technical path for the preparation of high areal density electrode sheets. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0028] Figure 1 Schematic diagram of the preparation process of the high areal density electrode sheet of the present application;

[0029] Figure 2 Scatter plot showing the correlation between different indexes of the examples and comparative examples and the areal density of gallium metal in the horizontal comparison test experiment of the present application. Specific embodiments

[0030] The following will describe the embodiments of the present invention in detail in combination with the examples. However, those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. For those not specified in the examples, they are carried out under conventional conditions or the conditions recommended by the manufacturer. Those reagents or instruments not specified by the manufacturer can be obtained as conventional products through commercial purchase.

[0031] Reference Figure 1 , in the embodiments of the present application, a preparation method of a high areal density electrode sheet is provided, including:

[0032] Step S1, preparing a pretreated positive electrode sheet;

[0033] Step S2, laying gallium metal particles on the surface of the pretreated positive electrode sheet to form a composite electrode sheet provided with a gallium metal template film;

[0034] Step S3, performing rolling treatment on the composite electrode sheet, and performing high-temperature heat treatment on the rolled composite electrode sheet to remove gallium metal, thereby obtaining a high areal density electrode sheet.

[0035] Gallium (chemical symbol: Ga) is a rare metal with unique physical and chemical properties. It is a gray-blue or silver-white metal with an atomic number of 31 and a relative atomic mass of 69.723. Gallium has an extremely low melting point of only 29.76 °C, while its boiling point is as high as 2403 °C, and its density is 5.904 g / cm 3 .

[0036] In the high areal density electrode preparation method described above, gallium metal particles are used as the template material, mainly taking advantage of their unique physical properties. Gallium metal has a low melting point (about 29.76 °C), remains liquid at room temperature, and can quickly melt and be discharged from the electrode when heated. This property enables gallium metal not to be damaged or disappear due to mechanical pressure during the rolling process, thus effectively maintaining the pore structure inside the electrode. In addition, the phase change process of gallium metal is a physical process and can be reused, significantly reducing the production cost while avoiding the impact of chemical residues on the electrode performance.

[0037] The pre-treated positive electrode refers to the electrode that needs to be surface-treated before the formal preparation of the electrode. For example, it can be a lithium iron phosphate positive electrode.

[0038] Its preparation method can include:

[0039] (1) Prepare the slurry; the slurry is prepared by mixing lithium iron phosphate, a conductive agent, and a binder, and a homogeneous slurry is obtained through a planetary dispersion kettle; the mass ratio of the lithium iron phosphate, the conductive agent, and the binder is 95:3:2;

[0040] (2) Coating: Use a coater to coat the slurry on an aluminum foil substrate;

[0041] (3) Drying: Perform a drying process to obtain a lithium iron phosphate positive electrode (pre-treated positive electrode).

[0042] As mentioned above, the rolling process is a key step in the electrode preparation process of this method. Its main function is to improve the density and thickness uniformity of the electrode surface material, improve the electron conductivity, and control the porosity of the electrode. Through rolling, the microstructure of the electrode is optimized, and the contact between particles becomes closer, thereby reducing the lithium ion transport distance and improving the energy density and rate performance of the battery. In addition, rolling can also enhance the mechanical strength of the electrode, making it more suitable for subsequent processing and assembly.

[0043] As mentioned above, the purpose of high-temperature heat treatment is to cause gallium metal to undergo a phase change, from solid state to liquid state, and be discharged from the electrode by heating. This process not only achieves the removal of gallium metal but also leaves a rich pore structure inside the electrode, thus achieving the technical goal of pore formation. High-temperature heat treatment can further optimize the microstructure of the electrode, improve the crystallinity and stability of the electrode, and thus enhance the overall performance of the battery.

[0044] The purpose of removing gallium metal is to form a uniform and stable pore structure inside the electrode. After gallium metal melts and is discharged at high temperature, the remaining pores provide channels for the transport of lithium ions, optimizing the ion conductivity of the electrode. At the same time, removing gallium metal can avoid its adverse reactions with the electrolyte or other materials during the operation of the battery, ensuring the safety and stability of the battery.

[0045] In an optional embodiment, the surface density of the gallium metal particles is 1 g / m 2 ~10 g / m 2 . For example, the surface density can be 1 g / m 2 , 2 g / m 2 , 4 g / m 2 , 6 g / m 2 , 8 g / m 2 , 10 g / m 2 and so on.

[0046] In an optional embodiment, for S2, laying gallium metal particles on the surface of the pretreated positive electrode sheet to form a composite electrode sheet provided with a gallium metal template thin film includes:

[0047] Placing the pretreated positive electrode sheet in an oven, placing the gallium metal particles on the surface of the pretreated positive electrode sheet, and controlling the heat preservation time to be 6 hours to 12 hours. Among them, the heat preservation time can be 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours and so on.

[0048] In an optional embodiment, during the roll pressing process, the ambient temperature is 10°C to 20°C. For example, the ambient temperature can be 10°C, 12°C, 14°C, 16°C, 18°C, 20°C and so on.

[0049] In an optional embodiment, during the roll pressing process, the ambient humidity is 10%RH to 30%RH. For example, the ambient humidity can be 10%RH, 15%RH, 20%RH, 25%RH, 30%RH and so on.

[0050] In an optional embodiment, performing high-temperature heat treatment on the composite electrode sheet after roll pressing to remove gallium metal to obtain a high-surface-density electrode sheet includes:

[0051] Placing the composite electrode sheet after roll pressing in an oven under vacuum conditions; and, the placement method of the composite electrode sheet after roll pressing is vertical placement, and a collection container is placed at the lower end of the composite electrode sheet so that the liquefied gallium metal can flow out of the composite electrode sheet by gravity and flow into the collection container.

[0052] Placing the composite electrode sheet after roll pressing in an oven under vacuum conditions. The vacuum environment helps to reduce the melting point of gallium metal, reduce the oxidation risk on the surface of the electrode sheet, and ensure that gallium metal can be smoothly discharged.

[0053] The composite electrode sheet is placed vertically. This placement method utilizes the gravity effect to enable the liquefied gallium metal to flow smoothly out of the electrode sheet.

[0054] A collection container can be placed at the lower end of the composite electrode sheet, specifically a polytetrafluoroethylene beaker or other containers that can withstand high temperatures and corrosion, for collecting liquefied gallium metal. This step ensures the recycling of gallium metal while avoiding contamination of the equipment by liquid gallium.

[0055] Through high-temperature heat treatment, the melting and discharging of gallium metal form a uniform pore structure, significantly improving the porosity and pore size distribution uniformity of the electrode sheet, thereby optimizing the electrochemical performance of the battery. The design of vertical placement and collection container ensures that the liquefied gallium metal can be smoothly discharged and recycled, reducing production costs and simultaneously reducing the potential impact on the environment. The vacuum environment reduces the melting point of gallium metal, reduces the oxidation risk on the surface of the electrode sheet, and improves the efficiency and safety of the heat treatment process. By precisely controlling the heat treatment temperature and vacuum degree, precise regulation of the pore structure can be achieved to meet the requirements of different application scenarios.

[0056] By providing a refined high-temperature heat treatment process, the smooth removal of gallium metal and the formation of the pore structure are ensured. The design of the vacuum environment, vertical placement, and collection container not only optimizes the pore structure but also realizes the recycling of gallium metal, reducing production costs.

[0057] In an alternative embodiment, the temperature of the oven under vacuum conditions is 90 °C to 100 °C. For example, the temperature can be 90 °C, 92 °C, 94 °C, 96 °C, 98 °C, 100 °C, and so on.

[0058] In the embodiments of the present application, a high areal density electrode sheet is provided, which is prepared by the preparation method of the high areal density electrode sheet according to any one of the foregoing embodiments.

[0059] In the embodiments of the present application, a battery is provided, including the high areal density electrode sheet according to the foregoing embodiments.

[0060] In the embodiments of the present application, an electricity-related device is provided, including the battery according to the foregoing embodiments.

[0061] The present invention will be further described below through specific embodiments. However, it should be understood that these embodiments are only for more detailed description and should not be construed as limiting the present invention in any form.

[0062] Table 1. Parameters in Examples and Comparative Examples

[0063] Component Range Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Gallium metal surface density <![CDATA[1 to 10 g / m 2 > 2 5 8 10 0 Insulation time 6～12H 10 10 10 10 10 Ambient temperature 20℃ 20 20 20 20 20 Ambient humidity 20%RH 20 20 20 20 20 Vacuum oven temperature 90～120℃ 100 100 100 100 100

[0064] Example 1

[0065] In this embodiment, the following method is used for preparation.

[0066] Preparation method:

[0067] (1) Preparation of the positive electrode plate: The slurry is prepared by mixing lithium iron phosphate, conductive agent, and binder, and a homogeneous slurry is obtained through a planetary dispersion kettle; the mass ratio of lithium iron phosphate, conductive agent, and binder is 95:3:2; the slurry is coated on an aluminum foil substrate using a coater and dried to obtain a lithium iron phosphate positive electrode plate;

[0068] (2) Transfer the lithium iron phosphate positive electrode plate to an oven, and use a translation device to evenly spray metallic gallium on the surface of the electrode plate, ensuring that the amount of gallium in each area is consistent. Adopt a multi-droplet or spraying technique to ensure that the metallic gallium is evenly distributed on the electrode plate; control the dropping or spraying speed of the metallic gallium (the recommended speed is 0.5 - 1.0 mL / min; the coverage area is the same as the surface area of the electrode plate, and the thickness is controlled within 0.3 mm ± 0.2). In this example, 1.0 mL / min is adopted; refer to Table 1 for the control of ambient temperature and humidity to avoid oxidation or volatilization of metallic gallium during the laying process. Thus, a composite electrode plate with a metallic gallium template film is formed.

[0069] (3) Roll press the composite electrode plate with a metallic gallium template film, and adjust the roll press pressure according to the thickness in the process design; refer to Table 1 for ambient temperature and humidity.

[0070] (4) Transfer the rolled composite electrode plate to a vacuum oven for the removal of gallium;

[0071] Among them, the placement method of the electrode plate is vertical placement; a tilted (tilt: 4 - 5°) polytetrafluoroethylene beaker liquid collection tank is placed below the electrode plate for collecting the liquefied and flowing metallic gallium; the gallium removal treatment can be operated in three stages: pre-removal - main removal - heat preservation. Pre-removal: At the front section of the vacuum oven at 90°C for 15 minutes, the solid gallium on the surface of the electrode plate is gradually removed; Main removal: The temperature of the vacuum oven is gradually raised to 120°C at a rate of 10°C / min for 30 minutes; Heat preservation: Keep at 120°C for 30 minutes to ensure that the residual gallium on the electrode plate is completely liquefied.

[0072] Refer to Table 1 for the temperature of the vacuum oven;

[0073] After removing the metallic gallium, a lithium iron phosphate positive electrode plate with rich pore channels is obtained. The lithium iron phosphate positive electrode plate with rich pore channels can observe the pore channel distribution through SEM + TEM or cross-section CP, and can also use the helium adsorption method (BET method) to measure the total pore volume or an electrolyte infiltration experiment to evaluate the effective porosity. The pore size on the surface of the electrode plate is recommended to be 60 - 80 nm (specifically refer to Table 1), which is helpful for electrolyte infiltration, and the pore size inside the electrode plate is recommended to be 100 - 180 nm, which is helpful for structural stability. The above detection means are all conventional tests in the industry.

[0074] Example 2

[0075] In this embodiment, the preparation is carried out by the method as in Embodiment 1.

[0076] Experimental scheme: The areal density of gallium metal is increased to 5 g / m 2

[0077] It is basically the same as Embodiment 1, and the differences are referred to the parameters in Table 1.

[0078] Embodiment 3

[0079] In this embodiment, the preparation is carried out by the method as in Embodiment 1.

[0080] Experimental scheme: The areal density of gallium metal is increased to 8 g / m 2

[0081] It is basically the same as Embodiment 1, and the differences are referred to the parameters in Table 1.

[0082] Embodiment 4

[0083] In this embodiment, the preparation is carried out by the method as in Embodiment 1.

[0084] Experimental scheme: The areal density of gallium metal is increased to 10 g / m 2

[0085] It is basically the same as Embodiment 1, and the differences are referred to the parameters in Table 1.

[0086] Comparative Example 1

[0087] In this comparative example, the preparation is carried out by the method as in Embodiment 1.

[0088] Experimental scheme:

[0089] It is basically the same as Embodiment 1, without adding gallium metal, the process in the experimental process is consistent with the experimental example, without any adjustment, and the differences are referred to the parameters in Table 1.

[0090] Horizontal comparative test experiment:

[0091] 1. Test method:

[0092] (1) 25 °C specific capacity test:

[0093] Assemble the prepared electrode sheets into a battery.

[0094] Perform charge-discharge tests at 25 °C and record the discharge capacity.

[0095] Calculate the discharge capacity per unit mass (mAh / g).

[0096] (2) 25 °C energy efficiency test:

[0097] Perform charge-discharge cycle tests at 25 °C.

[0098] Calculate the energy efficiency: Energy efficiency = Discharge energy / Charge energy × 100%.

[0099] (3) Aperture size test:

[0100] Use a scanning electron microscope (SEM) to observe the microstructure of the electrode sheet.

[0101] Measure the size of the pores and count the aperture size.

[0102] 2. Test results:

[0103] Table 2. Test results of examples and comparative examples

[0104] Component Range Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Gallium metal surface density <![CDATA[1 to 10 g / m 2 > 2 5 8 10 0 Capacity at 25°C 135 - 145 mAh / g 140 141 141 142 138 Energy efficiency at 25°C ≥93.5％ 94.2％ 94.5％ 94.4％ 94.3％ 93.8％ Internal pore size / 62 80 87 103 32

[0105] Analysis:

[0106] Referring to the data in Table 2, from the perspective of the cell grading data and energy efficiency data, both the grading gram capacity and energy efficiency increase significantly with the gradual increase of the gallium metal surface density, and the improvement efficiency ≥ 2%. Specifically, the gram capacities of Examples 1 to 4 are 140 mAh / g, 141 mAh / g, 141 mAh / g, and 142 mAh / g respectively. Compared with Comparative Example 1 without adding gallium metal (138 mAh / g), the gram capacities are increased by 1.4%, 2.2%, 2.2%, and 2.9% respectively. At the same time, the energy efficiency also shows a similar trend. The energy efficiencies of Examples 1 to 4 are 94.2%, 94.5%, 94.4%, and 94.3% respectively. Compared with Comparative Example 1 (93.8%), the energy efficiencies are increased by 0.4%, 0.7%, 0.6%, and 0.5% respectively. The correlation and trend can be referred to Figure 2 .

[0107] The change in the aperture size also increases with the increase of the gallium metal surface density. The aperture sizes of Examples 1 to 4 are 62 nm, 80 nm, 87 nm, and 103 nm respectively, while the aperture size of Comparative Example 1 is only 32 nm. The gradient experiment is beneficial to observing the change in the aperture size.

[0108] It can be seen from the aperture size that the increase in porosity can significantly enhance the infiltration rate of the electrolyte, reduce the interfacial impedance, thereby improving the conduction rates of ions and electrons, and further increasing the gram capacity. In addition, the optimization of the aperture size can also balance the ion transport efficiency and structural stability, alleviate the structural collapse of the electrode sheet during the rolling process, improve the energy density of the electrode sheet, and thus improve the energy efficiency.

[0109] In summary, the addition of gallium metal and the optimization of its areal density have a significant positive impact on the performance improvement of high-areal-density electrodes. As the areal density of gallium metal gradually increases, both the specific capacity and energy efficiency of the electrode are significantly improved, and the pore size also increases accordingly. These changes not only enhance the electrochemical performance of the electrode but also optimize its microstructure, making it more suitable for application scenarios with high energy density and high power output. Therefore, the addition and optimization of gallium metal provide an efficient, economical, and environmentally friendly technical path for the preparation of high-areal-density electrodes, with broad application prospects.

[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a high surface density electrode, characterized in that: include: S1, preparing a pretreated positive electrode sheet; S2, laying metal gallium particles on the surface of the pretreated positive electrode sheet to form a composite electrode sheet provided with a metal gallium template film; S3, rolling the composite electrode piece, and subjecting the rolled composite electrode piece to high-temperature heat treatment to remove the metal gallium, thereby obtaining a high-area-density electrode piece.

2. The method for preparing a high surface density electrode according to claim 1, wherein: The surface density of the metal gallium particles is 1 g / m 2 ~10g / m 2 .

3. The method for preparing a high surface density electrode according to claim 1, wherein: Said S2, laying metal gallium particles on the surface of said pretreated positive electrode sheet to form a composite electrode sheet provided with a metal gallium template film, comprises: The pretreated positive electrode sheet is placed in an oven, and the metal gallium particles are placed on the surface of the pretreated positive electrode sheet, and the heat preservation time is controlled to be 6 hours to 12 hours.

4. The method for preparing a high surface density electrode according to claim 1, wherein: During the roller pressing process, the ambient temperature is 10°C to 20°C.

5. The method for preparing a high surface density electrode according to claim 1, wherein: During the roller pressing process, the ambient humidity is 10% RH to 30% RH.

6. The method for preparing a high surface density electrode according to claim 1, wherein: The composite electrode piece after the rolling process is subjected to high-temperature heat treatment to remove the metal gallium to obtain a high-area density electrode piece, including: The composite electrode piece after the rolling process is placed in an oven under vacuum conditions; and the composite electrode piece after the rolling process is placed vertically, and a collection container is placed at the lower end of the composite electrode piece so that the liquefied metal gallium can flow out of the composite electrode piece by gravity and flow into the collection container.

7. The method for preparing a high surface density electrode according to claim 6, characterized in that: The temperature of the oven under the vacuum condition is 90° C. to 100° C.

8. A high surface density pole piece, characterized in that: It is prepared by the method for preparing a high surface density electrode as described in any one of claims 1 to 7.

9. A battery, characterized in that: Including the high surface density pole piece as described in claim 8.

10. An electrical equipment, characterized in that: Comprising the battery of claim 9.

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