Multi-stage buffer capacitor packaging structure, capacitor and preparation process of multi-stage buffer capacitor packaging structure

Abstract

The invention relates to the field of electrochemical energy storage devices, and discloses a multi-stage buffer capacitor packaging structure, a capacitor and a preparation process of the multi-stage buffer capacitor packaging structure. The multistage buffer capacitor packaging structure comprises a capacitor body and a shell, the capacitor body comprises a core and an aluminum shell, and nano-porous silica gel pads are compounded on a positive electrode plate and a negative electrode plate of the core; the inner wall of the aluminum shell is coated with an STF coating; the shell is a negative Poisson's ratio frame, the porosity is 60%, and the mass volume ratio of the shell is smaller than 2 g / cm < 3 >. According to the invention, the three-stage gradient buffer layer from the electrode to the shell is adopted for cooperative damping, broadband vibration energy absorption of 5-2000 Hz can be covered, the transmission of vibration energy to an electrode active material is inhibited, the integrity of a packaging structure is kept under long-term vibration, and meanwhile, the size and weight of a module are well balanced.

Description

Technical Field

[0001] The present invention relates to the field of electrochemical energy storage devices, and in particular to a multi-stage buffer capacitor packaging structure, a capacitor and a preparation process thereof. Background Art

[0002] Capacitors are components that store charge and energy, playing a vital role in circuits such as tuning, bypassing, coupling, and filtering. They are widely used in digital electronics, industrial equipment, and military applications. There are many different types of capacitors, especially military solid-state capacitors and supercapacitors, which are often subject to high-frequency vibrations, putting a strain on the capacitor's stability.

[0003] Existing technologies typically improve seismic performance by filling the gap between the housing and the electrodes with silicone or rubber, using a metal housing with bolts for fastening, or using springs and dampers to isolate external vibrations. However, these methods suffer from a limited buffering range, long-term performance degradation, accumulation of internal micro-damage, and increased volume and weight, which contradicts the need for lightweighting.

[0004] Therefore, the core problem of capacitors in the existing technology, namely, severe internal structural damage and rapid capacity decay under complex vibration environments, still needs to be solved. Summary of the Invention

[0005] The main purpose of the present invention is to propose a multi-stage buffer capacitor packaging structure to solve the technical problems of severe internal damage and rapid capacity decay of capacitors under complex vibration environments.

[0006] To achieve the above objectives, the present invention proposes a multi-stage buffer capacitor packaging structure, comprising a capacitor body and a shell. The capacitor body comprises a core and an aluminum shell. The positive electrode sheet and the negative electrode sheet of the core are both composited with a nanoporous silica gel pad. The inner wall of the aluminum shell is coated with a shear thickening liquid coating. The shell is a negative Poisson's ratio frame with a porosity of 60%. The mass-to-volume ratio of the shell is less than 2g / cm 3 .

[0007] The present invention adopts a three-level gradient buffer layer from the electrode to the shell to collaboratively eliminate vibrations, which can cover the wide-band vibration energy absorption of 5 to 2000 Hz, inhibit the transmission of vibration energy to the electrode active material, maintain the integrity of the packaging structure under long-term vibration, and at the same time well balance the module volume and weight.

[0008] Preferably, the nanoporous silica pad has a pore size of 50 to 200 nm and a porosity greater than 90%. The gas compression / expansion effect of the nanopores absorbs high-frequency micro-vibrations greater than 500 Hz, thereby reducing the risk of activated carbon particles falling off.

[0009] Preferably, the thickness of the shear thickening fluid coating is 200 μm. Shear thickening fluid (STF) is a well-known material, which is composed of SiO2 nanoparticles dispersed in polyethylene glycol. STF is coated on the inner wall of the capacitor aluminum shell. When the low-frequency vibration of 5 to 100 Hz is applied, the STF will produce a shear thickening effect, and the viscosity will instantly increase by 10 3 times, forming a rigid protective layer to prevent vibration energy from entering the interior.

[0010] Preferably, the shell is made of Ti-6Al-4V alloy material. The shell adopts a negative Poisson's ratio frame structure. When impacted, the structure contracts inward, converting the impact energy into structural deformation energy to avoid stress concentration.

[0011] On the other hand, the present invention further provides a capacitor comprising the multi-stage buffer capacitor packaging structure as described above.

[0012] The present invention also provides a process for preparing the capacitor, comprising the following steps:

[0013] S1. preparing a positive electrode sheet and a negative electrode sheet;

[0014] S2. Composite nanoporous silica pads on the positive electrode sheet and the negative electrode sheet by hot pressing;

[0015] S3, winding the positive electrode sheet, the negative electrode sheet and the electrolytic paper obtained in step S2 into a core;

[0016] S4, applying a shear thickening liquid coating on the inner wall of the aluminum shell;

[0017] S5, assembling the core into the aluminum shell, assembling the waist, and preparing the capacitor body after aging;

[0018] S6. Prepare a negative Poisson's ratio frame-type housing, snap-fit the capacitor body into the accommodating cavity of the housing, and complete the assembly to obtain the capacitor.

[0019] In step S2, the hot pressing temperature is 80±2°C and the pressure is 5 MPa.

[0020] In step S4, the shear thickening liquid coating is cured at 80±2° C. for 2 hours.

[0021] In the above manufacturing process, the inner sidewall of the housing is provided with a protrusion. When the capacitor body is placed in the housing cavity, the protrusion engages with the waist groove of the capacitor body. Preferably, the protrusion is arranged along the circumference of the inner sidewall of the housing. The protrusion structure on the inner sidewall of the housing is designed to engage with the waist groove of the capacitor body, making installation and removal convenient and simple.

[0022] Compared with the prior art, the present invention has at least the following beneficial effects: the present invention mainly absorbs high-frequency vibrations through nanoporous silica gel pads, reduces the shear stress on the electrode active material, and forms a primary buffer layer; the STF coating rigidly blocks the low-frequency vibration waves from entering the internal structure, forming a secondary buffer layer; the negative Poisson's ratio structure shell disperses energy to cope with instantaneous impact, forming a tertiary buffer layer; the three-level buffer is used to synergistically eliminate vibration: (1) the vibration tolerance is improved, and the electrode active material shedding rate is less than 0.5% and the capacity attenuation rate is ≤3% after testing for 100 hours under 10-2000Hz random vibration (acceleration 10Grms); (2) the environmental adaptability is improved, and the STF coating maintains stable shear thickening characteristics in the range of -40-120℃, and the impact resistance of the negative Poisson's ratio frame shell is improved by 160%-200%; (3) the capacitor is strong and compact, and the negative Poisson's ratio frame makes the overall structure of the capacitor lower in total weight than the traditional metal shell solution while maintaining the same volume share. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 This is a schematic structural diagram of the capacitor in the packaged state according to Example 1;

[0025] Figure 2 Schematic diagram of the capacitor structure of Example 1;

[0026] Figure 3 Schematic diagram of the structure of the core package in Example 1, Example 2, and Example 3;

[0027] Figure 4 This is a schematic structural diagram of the capacitor in the packaged state according to Example 2;

[0028] Figure 5 Schematic diagram of the capacitor structure of Example 2;

[0029] Figure 6 This is a schematic structural diagram of the capacitor in the packaged state according to Example 3;

[0030] Figure 7 Schematic diagram of the capacitor structure of Example 3.

[0031] In the accompanying drawings: 1-capacitor body, 11-core, 111-positive electrode sheet, 112-negative electrode sheet, 113-nanoporous silica pad, 114-electrolytic paper, 12-aluminum shell, 121-shear thickening liquid coating, 13-waist groove, 141-T-type connecting piece, 142-tower-shaped connecting piece, 143-L-type connecting piece, 144-resin cover, 151-foil guide strip, 152-ox horn cover, 161-guide pin, 162-rubber cover, 2-housing, 21-protrusion.

[0032] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. It should be noted that the embodiments in this application and the features in the embodiments can be combined with each other unless there is a conflict. At the same time, the raw materials mentioned below that are not described in detail are all commercially available products; the process steps or preparation methods not mentioned in detail are all process steps or preparation methods known to those skilled in the art.

[0034] The present invention provides a multi-stage buffer capacitor packaging structure, comprising a capacitor body and a shell. The capacitor body comprises a core and an aluminum shell. The positive electrode sheet and the negative electrode sheet of the core are both composited with a nanoporous silica pad. The nanoporous silica pad has a pore size of 50 to 200 nm and a porosity greater than 90%. The inner wall of the aluminum shell is coated with a shear thickening liquid coating with a thickness of 200 μm. The shell is a negative Poisson's ratio frame with a porosity of 60%. The mass-to-volume ratio of the shell is less than 2 g / cm 3 , using Ti-6Al-4V alloy material.

[0035] The present invention also provides a capacitor including the multi-stage buffer capacitor packaging structure, the preparation process of which includes the following steps:

[0036] S1. preparing a positive electrode sheet and a negative electrode sheet;

[0037] S2. Composite a nanoporous silica gel pad on the positive electrode sheet and the negative electrode sheet by hot pressing, with the hot pressing temperature being 80±2° C. and the pressure being 5 MPa;

[0038] S3, winding the positive electrode sheet, the negative electrode sheet and the electrolytic paper obtained in step S2 into a core;

[0039] S4. Apply a shear thickening liquid coating on the inner wall of the aluminum shell and cure it at 80±2°C for 2 hours;

[0040] S5. Assemble the core into the aluminum shell, assemble the waist, and prepare the capacitor body after aging;

[0041] S6. Prepare a negative Poisson's ratio frame-type housing, snap the capacitor body into the accommodating cavity of the housing, complete the assembly, and obtain the capacitor.

[0042] As can be understood, the present invention utilizes three levels of buffering layers for synergistic vibration damping. The first level is located within the electrode stack, combining the positive and negative electrodes with nanoporous silica pads. Nanoporous silica pads with a pore size of 50-200 nm and a porosity of 90% are inserted between each electrode layer. When vibration energy is transmitted to the electrode stack, the gas within the nanopores of the nanoporous silica pads undergoes adiabatically compression or expansion, converting mechanical energy into heat and dissipating it, thereby reducing the shear stress on the electrode active material. The second level of buffering is a 200μm-thick STF coating applied to the inner wall of the capacitor's aluminum casing. STF is a new functional material composed of a dispersed phase and a dispersion medium. The STF described in this invention consists of nanosilica particles dispersed in polyethylene glycol. Under normal conditions, the STF fluid is very soft and liquid. However, upon high-speed impact or compression, the STF material transforms from a liquid phase to a solid phase, becoming hard and absorbing the external force. Once the impact is eliminated, the solid phase quickly transforms back to a liquid phase, returning to its original soft state. This transformation is reversible. Therefore, when the vibration frequency triggers the shear thickening effect of the STF coating, the coating instantly hardens, forming a "rigid shell" that prevents low-frequency vibration waves from entering the internal structure. The third-level buffer is an external negative Poisson's ratio frame shell, made of Ti-6Al-4V alloy material through SLM 3D printing, with a porosity of 60% and a shell mass-to-volume ratio of less than 2g / cm. 3 , which can achieve lightweighting through a negative Poisson's ratio frame design. When the capacitor is subjected to a transient impact, the shell shrinks inward, absorbing energy through structural buckling while dispersing the local impact stress to the overall frame, preventing shell rupture.

[0043] In summary, the multi-level buffer structure provided by the present invention includes: a nanoporous silica pad (first-level buffer) absorbs high-frequency vibrations (>500Hz) through gas compression, an STF coating (second-level buffer) blocks low-frequency vibrations (5-100Hz) through shear thickening effect, and a negative Poisson's ratio shell (third-level buffer) disperses instantaneous impact energy through structural deformation. The three-level buffer layer works together through frequency segmentation and energy conversion mechanism to cover full-band vibration absorption, and can cope with low-frequency vibrations such as vehicle bumps, high-frequency vibrations such as motor noise, and instantaneous impacts caused by sudden braking or collisions, so that the capacitor has stronger environmental adaptability and vibration tolerance.

[0044] It should be noted that the multi-stage buffer capacitor packaging structure of the present invention is applicable to a variety of capacitor structures, including full-tab structure capacitors, horn type capacitors, guide pin type capacitors, etc. The following embodiments respectively demonstrate the performance characteristics of full-tab capacitors, horn type capacitors and guide pin type capacitors after adopting the multi-stage buffer packaging structure of the present invention. It should be noted that the core package structure in the preparation process of the above three capacitors with different structures is a structure formed by winding the known positive and negative electrode sheets and electrolytic paper, so they are all shown in the accompanying drawings as Figure 3 As an example.

[0045] Example 1

[0046] like Figures 1 to 3 The capacitor provided in this embodiment is a supercapacitor produced using a full-tab production process, comprising a capacitor body 1 and a shell 2. The capacitor body 1 comprises a core 11 and an aluminum shell 12. The positive electrode sheet 111 and the negative electrode sheet 112 of the core 11 are both composited with a nanoporous silica pad 113 with a pore size of 100 nm and a porosity greater than 90%. The inner wall of the aluminum shell is coated with an STF coating 121 with a thickness of 200 μm. The shell 2 is a negative Poisson's ratio frame made of Ti-6Al-4V material using SLM 3D printing, with a porosity of 60% and a shell mass-to-volume ratio of less than 2 g / cm. 3 The housing 2 has a receiving cavity, and an annular protrusion 21 is provided on the inner wall of the housing. The capacitor body 1 is placed in the receiving cavity, and the protrusion 21 is engaged in the waist groove 13 of the capacitor.

[0047] The manufacturing process of the capacitor of this embodiment includes the following steps:

[0048] S1, preparing a positive electrode sheet 111 and a negative electrode sheet 112;

[0049] S2. Composite nanoporous silica gel pad 113 on positive electrode sheet 111 and negative electrode sheet 112 by hot pressing process, with hot pressing temperature of 80° C. and pressure of 5 MPa;

[0050] S3, winding the positive electrode sheet 111 and the negative electrode sheet 112 obtained in step S2 into a core 11;

[0051] S4, coating the inner wall of the aluminum shell 12 with a shear thickening liquid coating 121, and curing it at 80° C. for 2 hours;

[0052] S5, assembling the core 11 obtained in step S3 into the aluminum shell 12, assembling the waist, and completing the test after charging and aging to prepare the capacitor body 1;

[0053] S6. Prepare a Ti-6Al-4V negative Poisson's ratio frame housing 2 by SLM 3D printing, snap the capacitor body 1 into the accommodating cavity of the housing 2, and complete the assembly to obtain a supercapacitor.

[0054] Referring to the well-known production process of full-tab process capacitors, specifically, in step S1, activated carbon, solvent, and conductive agent with a specific ratio are first stirred to form a slurry, which is coated on the collector to prepare an electrode foil and then rolled to form a positive electrode sheet 111 and a negative electrode sheet 112.

[0055] Specifically, in step S3, the positive electrode sheet 111 and the negative electrode sheet 112 behind the composite nanoporous silica gel pad 113 are cut and placed on a winding machine together with the electrolytic paper 114 to be wound into a core package of corresponding specifications. After shaping, the negative electrode T-shaped connecting piece 141 and the resin cover plate 144 are first welded together, and then welded to the negative end of the core package. At the same time, the positive electrode tower-shaped connecting piece 142 is welded to the positive electrode of the core package to obtain the core 11.

[0056] Specifically, in step S5, the core 11 is placed in the aluminum shell 12, the lead column of the tower-shaped connecting piece 142 and the bottom hole of the aluminum shell 12 are matched and welded, and after high-temperature baking and quantitative liquid injection, the waist is sealed, and the L-shaped connecting piece 143 is welded, charged and aged, and tested for capacity division to make the capacitor body 1.

[0057] Comparative Example 1

[0058] This comparative example is a BEC2R7V407SW3570 capacitor purchased from Zhaoqing Emerald Electronic Technology Co., Ltd., which is a traditional structure full-tab supercapacitor and adopts the same structural composition as Example 1. The only difference is that there is no nanoporous silicone pad between the electrodes, no STF coating on the aluminum shell, and no negative Poisson's ratio structure shell.

[0059] The vibration resistance of the supercapacitors of Example 1 and Comparative Example 1 was tested using the following test standards and methods:

[0060] (1) Capacitor vibration test: Test for 100 hours under 10-2000 Hz random vibration (acceleration 10 Grms) to detect the electrode active material shedding rate and capacity decay rate.

[0061] (2) Impact resistance: Refer to ASTM D7136 drop hammer test.

[0062] The test results are shown in Table 1.

[0063] Table 1

[0064]

[0065]

[0066] Example 2

[0067] The multi-stage buffer anti-vibration structure of the present invention can also be applied to the production process of horn type capacitors, such as Figures 4-5 The capacitor of this embodiment is a horn type capacitor, including a capacitor body 1 and a shell 2. The capacitor body includes a core 11 and an aluminum shell 12. Figure 3 The positive electrode sheet 111 and the negative electrode sheet 112 of the core 11 are both composited with a nanoporous silica pad 113 with a pore size of 150nm and a porosity of >90%. The inner wall of the aluminum shell 12 is coated with an STF coating 121 with a thickness of 200μm. The outer shell 2 is a negative Poisson's ratio frame made of SLM 3D printed Ti-6Al-4V material with a porosity of 60% and an outer shell mass volume ratio of <2g / cm 3 The housing 2 has a receiving cavity, and an annular protrusion 21 is provided on the inner wall of the housing 2. The capacitor body 1 is placed in the receiving cavity, and the protrusion 21 is engaged with the waist groove 13 of the capacitor.

[0068] The manufacturing process of the capacitor of this embodiment includes the following steps:

[0069] S1. Activated carbon, a solvent, and a conductive agent in a specific ratio are stirred into a slurry, which is coated onto a current collector to prepare an electrode foil, which is then rolled to form a positive electrode sheet 111 and a negative electrode sheet 112;

[0070] S2. Composite nanoporous silica gel pad 113 on positive electrode sheet 111 and negative electrode sheet 112 by hot pressing process, with hot pressing temperature of 80° C. and pressure of 5 MPa;

[0071] S3, cutting the positive electrode sheet 111 and the negative electrode sheet 112 obtained in step S2 and placing them together with the electrolytic paper 114 on a winding and riveting machine, riveting the conductive foil strip 151 to the positive and negative electrodes by cold riveting, winding them into a core 11, and riveting them to the horn cover plate 152;

[0072] S4, coating the inner wall of the aluminum shell 12 with a shear thickening liquid coating 121, and curing it at 80° C. for 2 hours;

[0073] S5, after high-temperature baking, the core 11 obtained in step S3 is placed in the aluminum shell 12, quantitatively injected with liquid, waisted and sealed, charged and aged, and tested for capacitance, thereby manufacturing the capacitor body 1;

[0074] S6. Prepare a Ti-6Al-4V negative Poisson's ratio frame housing 2 by SLM 3D printing, and snap the capacitor body 1 into the accommodating cavity of the housing 2 to complete the assembly, thereby obtaining the capacitor of this embodiment.

[0075] Comparative Example 2

[0076] This comparative example uses BCC2R7V607TZ3570 capacitors purchased from Zhaoqing Emerald Electronics Technology Co., Ltd. These are traditional horn-type capacitors with the same structural composition as Example 2, differing only in the absence of a nanoporous silicone pad between the electrodes, the absence of an STF coating on the aluminum shell, and the lack of a negative Poisson's ratio housing.

[0077] The vibration resistance of the capacitors of Example 2 and Comparative Example 2 was tested using the following test standards and methods:

[0078] (1) Capacitor vibration test: Test for 100 hours under 10-2000 Hz random vibration (acceleration 10 Grms) to detect the electrode active material shedding rate and capacity decay rate.

[0079] (2) Impact resistance: Refer to ASTM D7136 drop hammer test.

[0080] The test results are shown in Table 2.

[0081] Table 2

[0082] Electrode active material shedding rate Capacity decay rate Impact resistance Example 2 0.39％ 2.89％ 15.4J Comparative Example 2 1.02％ 17.18％ 4.8J

[0083] Example 3

[0084] Reference Figures 6-7 The capacitor of this embodiment is a pin-type capacitor, comprising a capacitor body 1 and a housing 2. The capacitor body 1 comprises a core 11 and an aluminum shell 12. Figure 3 The positive electrode sheet 111 and the negative electrode sheet 112 of the core 11 are both composited with nanoporous silica gel with a pore size of 80nm and a porosity of >90%. The inner wall of the aluminum shell 12 is coated with an STF coating 121 with a thickness of 200μm. The outer shell 2 is a negative Poisson's ratio frame made of SLM 3D printed Ti-6Al-4V material with a porosity of 60% and an outer shell mass volume ratio of <2g / cm 3 The housing 2 has a receiving cavity, and an annular protrusion 21 is provided on the inner wall of the housing 2. The capacitor body 1 is placed in the receiving cavity, and the protrusion 21 is engaged with the waist groove 13 of the capacitor.

[0085] The manufacturing process of the capacitor of this embodiment includes the following steps:

[0086] S1. Activated carbon, a solvent, and a conductive agent in a specific ratio are stirred into a slurry, which is coated onto a current collector to prepare an electrode foil, which is then rolled to form a positive electrode sheet 111 and a negative electrode sheet 112;

[0087] S2. Composite nanoporous silica gel pad 113 on positive electrode sheet 111 and negative electrode sheet 112 by hot pressing process, with hot pressing temperature of 80° C. and pressure of 5 MPa;

[0088] S3, cutting the positive electrode sheet 111 and the negative electrode sheet 112 obtained in step S2 and placing them together with the electrolytic paper 114 on a nailing and winding machine, connecting the positive and negative electrode nails to the guide pins 161, and winding them into a core 11 of corresponding specifications;

[0089] S4, coating the inner wall of the aluminum shell 12 with a shear thickening liquid coating 121, and curing it at 80° C. for 2 hours;

[0090] S5, baking and impregnating the core 11 obtained in step S3, assembling and sealing, charging and aging, testing and dividing the capacitance, and manufacturing the capacitor body 1;

[0091] S6. Prepare a Ti-6Al-4V negative Poisson's ratio frame housing 2 by SLM 3D printing, and snap the capacitor body 1 into the accommodating cavity of the housing 2 to complete the assembly, thereby obtaining the capacitor of this embodiment.

[0092] Comparative Example 3

[0093] This comparative example is a BCC2R7M706YS1840 capacitor purchased from Zhaoqing Emerald Electronic Technology Co., Ltd., which is a traditional guide pin type capacitor and adopts the same structural composition as Example 3. The only difference is that there is no nanoporous silicone pad between the electrodes, no STF coating on the aluminum shell, and no negative Poisson's ratio structure shell.

[0094] The vibration resistance of the capacitors of Example 3 and Comparative Example 3 was tested using the following test standards and methods:

[0095] (1) Capacitor vibration test: Test for 100 hours under 10-2000 Hz random vibration (acceleration 10 Grms) to detect the electrode active material shedding rate and capacity decay rate.

[0096] (2) Impact resistance: Refer to ASTM D7136 drop hammer test.

[0097] The test results are shown in Table 3.

[0098] Table 3

[0099] Electrode active material shedding rate Capacity decay rate Impact resistance Example 3 0.27％ 2.23％ 9.8J Comparative Example 3 1.08％ 15.34％ 2.5J

[0100] As can be seen from Tables 1 to 3, the vibration resistance and impact resistance of the capacitor using the multi-stage buffer anti-vibration structure of the present invention are better than those of the capacitor with the traditional structure. In the capacitor vibration test, the electrode active material shedding rate of the capacitor with the multi-stage buffer anti-vibration structure of the present invention is as low as 0.27% to 0.42%, which is significantly lower than that of the capacitor with the traditional structure; the capacity attenuation rate is 2.23% to 2.55%, which is significantly lower than that of the capacitor with the traditional structure; at the same time, it has excellent impact resistance. In the drop hammer test, the impact resistance of the capacitors of Examples 1 and 2 is as high as 15.4 to 16.2J. The guide pin type capacitor structure of Example 3 is small in size, the stress is more concentrated, and the impact resistance is slightly lower, which can reach 9.8J, but it is still significantly better than the impact resistance of the capacitor with the traditional structure (Comparative Example 3). All performances are better than those of the capacitor with the traditional structure.

[0101] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention specification under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A multi-stage buffer capacitor packaging structure, characterized in that: The invention comprises a capacitor body (1) and a shell (2), wherein the capacitor body (1) comprises a core (11) and an aluminum shell (12), wherein the positive electrode sheet (111) and the negative electrode sheet (112) of the core (11) are both composited with a nanoporous silica gel pad (113); the inner wall of the aluminum shell (12) is coated with a shear thickening liquid coating (121); the shell (2) is a negative Poisson's ratio frame with a porosity of 60%, and the mass-to-volume ratio of the shell is less than 2 g / cm 3 .

2. The multi-stage buffer capacitor packaging structure according to claim 1, wherein: The pore size of the nanoporous silica gel pad (113) is 50-200 nm, and the porosity is greater than 90%.

3. The multi-stage buffer capacitor packaging structure according to claim 1, wherein: The thickness of the shear thickening fluid coating (113) is 200 μm.

4. The multi-stage buffer capacitor packaging structure according to claim 1, wherein: The shell (2) is made of Ti-6Al-4V alloy material.

5. A capacitor, characterized in that: The invention comprises the multi-stage buffer capacitor packaging structure as claimed in any one of claims 1 to 4.

6. A process for preparing a capacitor according to claim 5, characterized in that: The steps include: S1, preparing a positive electrode sheet (111) and a negative electrode sheet (112); S2, compounding a nanoporous silica gel pad (113) on the positive electrode sheet (111) and the negative electrode sheet (112) through a hot pressing process; S3, winding the positive electrode sheet (111), the negative electrode sheet (112) and the electrolytic paper (114) obtained in step S2 into a core; S4, coating the inner wall of the aluminum shell (12) with a shear thickening liquid coating (121); S5, assembling the core (11) into the aluminum shell (12), assembling the waist, and preparing the capacitor body (1) after aging; S6. Prepare a negative Poisson's ratio frame-type housing (2), snap the capacitor body (1) into the accommodating cavity of the housing (2), complete the assembly, and obtain the capacitor.

7. The preparation process according to claim 6, wherein: In step S2, the hot pressing temperature is 80±2°C and the pressure is 5 MPa.

8. The preparation process according to claim 6, wherein: In step S4, the shear thickening liquid coating is cured at 80±2° C. for 2 hours.

9. The preparation process according to claim 6, wherein: The inner side wall of the shell (2) is provided with a protrusion (21); when the capacitor body (1) is placed in the accommodating cavity of the shell (2), the protrusion (21) is inserted into the waist groove (13) of the capacitor body (1).

10. The preparation process according to claim 9, characterized in that: The protrusion (21) is arranged along the circumference of the inner side wall of the shell (2).

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