An integrated solid-state battery module based on SiO2 aerogel powder and its preparation method

Abstract

This invention relates to the field of electrochemical energy storage technology, providing an integrated solid-state battery module based on SiO2 aerogel powder and its preparation method. This battery module incorporates Janus-structured SiO2 aerogel powder with dual stress-thermal response capabilities to construct a synergistic interface system of stress buffering, ion conduction, and thermally triggered self-healing. The Janus powder forms a rigid core with ZrO2 nanoclusters and a SiO2 network, with a dynamic shell containing Diels-Alder dynamic covalent bonds grafted onto its outer surface and pore inner walls. A lithium salt-ionic liquid composite is loaded into the pores. A vertical columnar stress-supporting framework is formed through a transient liquid-phase assisted cold sintering process. Combined with a two-step thermally triggered self-healing treatment, stress buffering of electrode volume changes during charging and discharging, and interface self-healing in the early stages of thermal abuse are achieved. This invention significantly improves the interface stability, cycle life, and thermal safety of solid-state batteries, making it suitable for applications such as power batteries and high-capacity energy storage batteries.

Description

Technical Field

[0001] This invention belongs to the field of electrochemical energy storage technology, and particularly relates to an integrated solid-state battery module based on SiO2 aerogel powder and its preparation method. Background Technology

[0002] Solid-state batteries, as a core development direction of next-generation energy storage technology, have attracted widespread attention from academia and industry due to their advantages such as high energy density, low leakage risk, and good safety, which are achieved by using solid electrolytes instead of traditional liquid electrolytes. However, most solid-state batteries still use the traditional stacked structure of independent electrode layers and electrolyte layers. This design leads to poor interfacial contact between the electrode and electrolyte, high interfacial impedance, long and inefficient ion transport paths, and safety hazards such as thermal runaway under high current or high temperature conditions.

[0003] On the other hand, SiO2 aerogel, as a lightweight nanoporous material, has extremely low density, high specific surface area, excellent thermal stability, and flame retardant properties, and has been explored for use in battery separators or as a functional additive. However, traditional applications have failed to fully utilize its porous framework, thermal insulation properties, and structural designability, especially lacking a systematic approach to using it as an integrated structural material to simultaneously construct the four core components of a battery—the positive electrode, negative electrode, electrolyte, and separator.

[0004] Currently, there are no reports of using functionalized SiO2 aerogel powder to achieve integrated battery design through material synthesis and structural innovation. Therefore, this invention proposes to use SiO2 aerogel as the base material, and through surface functionalization modification combined with innovative preparation processes, to achieve structural and functional integration of the positive electrode, negative electrode, solid electrolyte, and separator in a single material system. This effectively reduces interfacial impedance, shortens ion migration paths, and significantly improves the thermal safety and overall electrochemical performance of the battery. Summary of the Invention

[0005] This invention provides an integrated solid-state battery module based on SiO2 aerogel powder and its preparation method, aiming to solve the above-mentioned problems.

[0006] The present invention is implemented as follows: an integrated solid-state battery module based on SiO2 aerogel powder, comprising a positive electrode layer, a negative electrode layer and a solid electrolyte layer located therebetween, wherein the solid electrolyte layer is composed of Janus structure SiO2 aerogel powder, and both the positive electrode layer and the negative electrode layer contain the Janus structure SiO2 aerogel powder.

[0007] The Janus-structured SiO2 aerogel powder comprises a rigid core and a dynamic shell. The rigid core is formed by ZrO2 nanocrystal clusters and a SiO2 network chemically bonded together via Zr-O-Si bonds, providing mechanical strength to buffer electrode volume changes. The dynamic shell is a cross-linked polymer layer containing dynamic covalent bonds covering the outer surface of the rigid core and the inner walls of the large pores. During thermal abuse, it can achieve self-repair through bond breakage and recombination. Boron nitride (BN) nanosheets can be loaded onto the surface and pores of the aerogel powder. Utilizing the high thermal conductivity and barrier properties of BN, the heat dissipation efficiency and flame retardant performance of the battery module can be further improved.

[0008] Preferably, the dynamic covalent bond is a Diels-Alder (DA) bond, and the crosslinked polymer layer is formed by polymerizing diene-functionalized silane and dienophilic functionalized silane through a Diels-Alder reaction; the diene-functionalized silane is selected from at least one of furan-functionalized silane and anthracene-functionalized silane, and the dienophilic functionalized silane is selected from at least one of maleimide-functionalized silane and norbornenediimide-functionalized silane.

[0009] Preferably, the three-dimensional pores of the Janus-structured SiO2 aerogel powder are loaded with a lithium salt-ionic liquid complex; the lithium salt is selected from at least one of lithium bis(trifluoromethanesulfonyl)imide and lithium bis(fluorosulfonyl)imide, and the ionic liquid is selected from at least one of 1-propyl-3-methylpyridine bis(trifluoromethanesulfonyl)imide and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide. The lithium salt-ionic liquid complex loaded in the pores constructs a continuous ion transport channel, enabling the aerogel powder to have lithium ion conductivity. The aerogel not only serves as a structural framework but also as part of a solid electrolyte.

[0010] Preferably, the positive and negative electrode layers are internally formed with a stress-supported framework consisting of a rigid core orientation of Janus structure SiO2 aerogel powder, and the gaps between the framework are filled with electrode active material and conductive agent. The orientation of the framework is conducive to ion transport perpendicular to the current collector direction.

[0011] Preferably, the mass percentage of Janus structure SiO2 aerogel powder in the positive electrode layer is 10-20%, and its mass percentage in the negative electrode layer is 8-15%; the mass percentage of ZrO2 nanocrystal clusters in the rigid core is 3-8%.

[0012] The present invention also provides a method for preparing the integrated solid-state battery module based on SiO2 aerogel powder, comprising the following steps:

[0013] S1: Preparation of Janus-structured SiO2 aerogel powder;

[0014] S2: The powder obtained in S1 is mixed with the positive electrode active material and the conductive agent (mixed using a three-dimensional mixer or ball mill, with the mixing time controlled at 20-60 minutes) to prepare the positive electrode composite powder, and mixed with the negative electrode active material and the conductive agent (mixed using a three-dimensional mixer or ball mill, with the mixing time controlled at 20-60 minutes) to prepare the negative electrode composite powder.

[0015] S3: The positive electrode composite powder, the Janus structure SiO2 aerogel powder as the electrolyte layer, and the negative electrode composite powder are stacked in the mold in the following order: positive electrode composite powder → Janus structure SiO2 aerogel powder as the electrolyte layer → negative electrode composite powder. Transient liquid phase additives are uniformly sprayed onto the surface and interlayer of the stacked structure by spraying, allowing the additives to penetrate into the gaps between the powders. The mass of each powder layer is designed according to the target battery capacity. As an example, the mass ratio of positive electrode composite powder, electrolyte layer powder, and negative electrode composite powder can be controlled between (8-12):1:(8-12).

[0016] S4: Apply 200-500MPa pressure to the stacked structure and perform cold sintering at 80-150℃, holding the temperature and pressure for 5-15 minutes to form an integrated battery blank;

[0017] S5: The battery blank is placed in an inert atmosphere and subjected to a two-step heat treatment: First, it is kept at a first temperature (80-100℃, below the reverse reaction temperature of the dynamic covalent bond, but above the glass transition temperature (Tg) of the crosslinked polymer layer, at which point the polymer chain segment mobility is enhanced, which can effectively promote interface diffusion and fusion without destroying the dynamic covalent network) for 20-40 minutes to achieve interface fusion. Then, it is kept at a second temperature higher than the first temperature for 2-5 minutes to achieve thermally triggered self-healing. The second temperature is not lower than the reverse reaction trigger temperature of the dynamic covalent bond in the Janus structure SiO2 aerogel powder. After cooling, a stress-adaptive solid-state battery module is obtained.

[0018] The transient liquid phase auxiliary agent-assisted cold sintering process, under pressure, forms a liquid film that effectively reduces interparticle friction, promotes particle sliding, rearrangement, and plastic deformation, and forms a vertical columnar stress-supported skeleton. At the same time, it causes the ionic liquid in the dynamic shell to be squeezed out and fill the gaps in the skeleton, constructing a low-torsion ion superfluid channel. At 80-150℃, the auxiliary agent can temporarily dissolve the surface material of the powder, greatly accelerating the material transport at the interface and achieving densification. Subsequently, during the heat preservation stage or subsequent heat treatment, the auxiliary agent can completely volatilize or decompose without leaving any residue, forming a dense integrated structure.

[0019] Two-step thermally triggered self-healing post-treatment: Step 1 (80-100℃) interface fusion promotes the diffusion of DA-bonded polymer segments and reduces interface impedance; Step 2 (not lower than the reverse DA reaction temperature, the Diels-Alder reverse reaction temperature of furan-functionalized silane-maleimide-functionalized silane system is 120-150℃, corresponding to a second temperature of 130-150℃; the reverse reaction temperature of anthracene-functionalized silane-maleimide-functionalized silane system is >200℃, corresponding to a second temperature of 180-220℃) thermally triggered self-healing, enabling reversible breakage of DA bonds, healing microcracks generated by cold sintering, and locking the repaired structure after cooling to ensure long-term interface stability.

[0020] Janus powder provides "rigid-dynamic" composite properties for cold sintering, while cold sintering provides a target for self-healing (dense structure and microcracks). Self-healing provides stability assurance for cold sintered structures, forming a closed loop of "material-structure-function".

[0021] Preferably, the preparation of Janus-structured SiO2 aerogel powder in S1 includes the following steps:

[0022] S1.1: Mix the silicon source (at least one of methyl orthosilicate and tetraethyl orthosilicate) with the solvent (a mixture of ethanol and deionized water), add an acid catalyst to adjust the pH to 1-3, and perform pre-hydrolysis for 0.5-2 hours; then add the zirconium source (at least one of zirconium oxychloride and zirconium nitrate), stir evenly, add an alkaline catalyst to adjust the pH to 4-6, and allow the gel to stand to obtain ZrO2@SiO2 composite wet gel; the molar ratio of the silicon source, deionized water, ethanol and zirconium source in the solvent is: 1:(3-6):(3-5):(0.01-0.15).

[0023] S1.2: The composite wet gel is aged at 40-60℃ for 12-36 hours, and then immersed in an aminosilane solution (mass concentration of 3%-8%, the mass-volume ratio of the composite wet gel to the aminosilane solution is 1g:(5-15)mL) for 10-16 hours to introduce amino functional groups.

[0024] S1.3: Immerse the aminated gel in a diene-dienophile composite monomer solution (the total mass of the monomer is 0.5%-5% of the solvent mass; the mass-volume ratio of the aminated gel to the composite monomer solution is 1g:(8-20)mL) and react at 50-70℃ for 18-30 hours to form a cross-linked polymer layer containing dynamic covalent bonds.

[0025] S1.4: The gel was subjected to supercritical drying and ball milled to a particle size D50 = 2-5 μm to obtain Janus structure SiO2 aerogel dry powder;

[0026] S1.5: Immerse the dry powder in a lithium salt-ionic liquid composite at 50-70℃ and a vacuum degree ≤10Pa for 2-6 hours, and then vacuum impregnate it with the loaded electrolyte.

[0027] A stepwise hydrolysis process was employed: first, the silicon source was pre-hydrolyzed to generate siloxane oligomers with a certain degree of polymerization, and then a zirconium source was introduced. This method utilizes the differences in hydrolysis rate and isoelectric point between the silicon and zirconium sources: under acidic conditions, the silicon source hydrolyzes preferentially and at a slower rate, forming a uniform reaction environment; subsequently, under weakly acidic to near-neutral conditions (pH=4-6), the zirconium source rapidly hydrolyzes and, with its abundant hydroxyl groups, undergoes co-condensation with the pre-hydrolyzed siloxane oligomers, anchoring ZrO2 nanocrystal clusters within the forming SiO2 network through Zr-O-Si bonds. This process effectively suppresses independent and excessive nucleation and Ostwald ripening of ZrO2, ensuring the successful construction of nanoscale (5-10 nm), highly dispersed rigid cores, achieving excellent mechanical and ion transport properties.

[0028] Preferably, the transient liquid phase additive in S3 is selected from ethanol aqueous solution and / or dilute acetic acid solution, and the addition amount is 1-5% of the total mass of the powder; the volume ratio of the ethanol aqueous solution is 1:1-3, the mass concentration of the dilute acetic acid solution is 0.5-2%, the nozzle orifice diameter of the spray method is 0.1-0.5 mm, and the spray pressure is 0.1-0.3 MPa, to ensure that the additive uniformly covers the powder surface without obvious liquid accumulation.

[0029] Preferably, a pulsed current is applied during the cold sintering process in S4, with a pulsed current density of 10-50 mA / cm². 2 With a pulse frequency of 1-5Hz and a duty cycle of 30-50%, the ionic liquid is squeezed out of the dynamic shell and fills the gaps in the rigid skeleton under the combined action of pressure and pulse current, forming a low-bending transmission channel.

[0030] Preferably, during the S4 cold sintering process, an external physical field perpendicular to the mold plane is simultaneously applied. The external physical field is a magnetic field or a DC electric field. When it is a magnetic field, the ZrO2 nanocrystal clusters in the Janus structure SiO2 aerogel powder are modified by superparamagnetic nanoparticles (such as Fe3O4, where both Fe3O4 and ZrO2 are oxides and their surface hydroxyl groups can form hydrogen bonds to ensure modification stability). The mass of the superparamagnetic nanoparticles accounts for 1-3% of the Janus powder, the particle size is 5-10 nm, and the magnetic induction intensity is 0.1-1.0 T. When it is a DC electric field, the field strength is 0.5-5 kV / cm. By accelerating the migration of ionic liquids through pulsed current and guiding the magnetic / electric field, the anisotropic Janus powder (or its rigid core) is more effectively driven to oriented along the field line direction, making the vertical columnar skeleton more regular and the ion transport channels more unobstructed.

[0031] Compared with the prior art, the embodiments of this application have the following main advantages:

[0032] Significantly improved interface stability: The vertical columnar stress support skeleton can effectively buffer the volume expansion of silicon-based anodes by more than 300%, and the interface impedance increase is less than 20% after 500 cycles, with a capacity retention rate of more than 91%.

[0033] Thermal safety is significantly enhanced: In the early stages of thermal abuse, ion channels can be rebuilt through self-repair of DA bonds to avoid local heat accumulation. The maximum temperature in the needle puncture test is <150℃, with no fire or explosion.

[0034] Optimized ion conduction efficiency: The ion superfluid channel significantly reduces transport resistance, achieving an ion conductivity of 8.5 × 10⁻⁶. -4 The S / cm ratio is above that of conventional solid electrolytes. Attached Figure Description

[0035] Figure 1 This is a flowchart of a method for preparing an integrated solid-state battery module based on SiO2 aerogel powder, provided by the present invention.

[0036] Figure 2 This is a flowchart of the preparation method of Janus structure SiO2 aerogel powder provided by the present invention. Detailed Implementation

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, not to describe a particular order.

[0038] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0039] Raw materials and equipment

[0040] Silicon source: Tetraethyl orthosilicate (TEOS)

[0041] Zirconium source: Zirconium oxychloride (ZrOCl2·8H2O)

[0042] Aminosilane: 3-Aminopropyltriethoxysilane (APTES)

[0043] DA reaction monomers: furan-modified maleimide (Fu-MI), anthracene-functionalized silane, maleimide-functionalized silane

[0044] Lithium salt: Lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)

[0045] Ionic liquid: 1-propyl-3-methylpyridine bis(trifluoromethanesulfonyl)imide salt ([PYR13][TFSI])

[0046] Positive electrode active material: LiNi 0·8 Co 0·1 Mn 0·1 O2 (NCM811), LiFePO4 (LFP)

[0047] Negative electrode active material: artificial graphite, silicon-carbon composite material (Si / C, Si content 30wt%).

[0048] Conductive agent: Conductive carbon black (Super P)

[0049] Transient liquid phase additives: ethanol aqueous solution (volume ratio 1:1), dilute acetic acid (1wt%)

[0050] Equipment: High-pressure cold press (up to 500MPa, with heating and pulse current functions), supercritical CO2 dryer, glove box.

[0051] Example 1: Basic System (NCM811 / Graphite)

[0052] This invention provides an integrated solid-state battery module based on SiO2 aerogel powder, such as... Figures 1-2 As shown, its preparation method includes the following steps:

[0053] S1: Preparation of Janus-structured SiO2 aerogel powder A:

[0054] S1.1: Mix TEOS, ethanol, and deionized water in a 1:4:4 molar ratio, adjust the pH to 2 with 0.1M HCl, and pre-hydrolyze at 40°C for 1 hour. Add ZrOCl2·8H2O, equivalent to 8% of the theoretical SiO2 mass of ZrO2, stir for 30 minutes, adjust the pH to 5 with 0.1M ammonia, allow the gel to stand, and age at 50°C for 24 hours.

[0055] S1.2: Immerse the wet gel in 10 times the gel volume of 5wt% APTES ethanol solution for 12 hours, and wash with ethanol 3 times.

[0056] S1.3: Immerse the aminated gel in 10 times the gel volume of 0.2M Fu-MI DMF solution and react at 60°C for 24 hours, then wash with DMF and ethanol.

[0057] S1.4: Perform supercritical CO2 drying (31℃, 7.4MPa) and ball mill to D50=3μm.

[0058] S1.5: At 60℃ and 5Pa vacuum, the dry powder was immersed in 1M LiTFSI / [PYR13][TFSI] ionic liquid for 4 hours to obtain powder A.

[0059] Battery module fabrication:

[0060] S2: Positive electrode composite powder: Powder A (15wt%) + NCM811 (80wt%) + Super P (5wt%), mixed in a three-dimensional mixer at 200rpm for 40 minutes. Negative electrode composite powder: Powder A (10wt%) + artificial graphite (85wt%) + Super P (5wt%), mixed in the same way.

[0061] S3: In the mold, the following are sequentially layered: 120mg positive electrode composite powder → 25mg pure powder A (electrolyte layer) → 110mg negative electrode composite powder. A 2% (volume ratio 1:1) ethanol-water solution of the total powder mass is sprayed. After thermogravimetric analysis (TGA), cold sintering, and subsequent heat treatment, no residual transient liquid phase additives were detected in the battery blank (residual amount <0.1wt%), indicating complete volatilization of the additives and no impact on the battery's electrochemical performance.

[0062] S4: Cold sintering: Apply a pressure of 400 MPa at a rate of 5 MPa / s, while simultaneously heating to 120 °C at a rate of 10 °C / min, holding at that temperature and pressure for 10 minutes, and applying a pulsed current (30 mA / cm²). 2 (3Hz, 40% duty cycle).

[0063] S5: Heat treatment: Under an argon atmosphere, the temperature is increased to 90°C at 10°C / min and held for 30 minutes; then the temperature is increased to 140°C at 10°C / min and held for 3 minutes; then the furnace is cooled to room temperature to obtain battery module E1.

[0064] Example 2: High energy density system (NCM811 / silicon-carbon)

[0065] This invention provides an integrated solid-state battery module based on SiO2 aerogel powder, such as... Figures 1-2 As shown, its preparation method includes the following steps:

[0066] S1: Same as in Example 1, prepare powder A.

[0067] Battery module fabrication:

[0068] S2: Positive electrode composite powder: Powder A (18wt%) + NCM811 (77wt%) + Super P (5wt%). Negative electrode composite powder: Powder A (15wt%) + silicon-carbon composite material (80wt%) + Super P (5wt%).

[0069] S3: Lamination: 150mg positive electrode composite powder → 30mg pure powder A → 80mg negative electrode composite powder. Spray with 2% ethanol aqueous solution.

[0070] S4: Cold sintering: Apply a pressure of 450MPa at 5MPa / s, raise the temperature to 130℃ at 10℃ / min, hold the temperature and pressure for 12 minutes, and use the same pulse current as in Example 1.

[0071] S5: Heat treatment: Heat to 95℃ at 10℃ / min and hold for 35 minutes; then heat to 145℃ and hold for 4 minutes; cool with the furnace to obtain battery module E2.

[0072] Example 3: High-safety / power system (LFP / graphite)

[0073] This invention provides an integrated solid-state battery module based on SiO2 aerogel powder, such as... Figures 1-2 As shown, its preparation method includes the following steps:

[0074] S1: Same as in Example 1, prepare powder A.

[0075] Battery module fabrication:

[0076] S2: Positive electrode composite powder: Powder A (12wt%) + LFP (83wt%) + Super P (5wt%). Negative electrode composite powder: Powder A (8wt%) + Artificial graphite (87wt%) + Super P (5wt%).

[0077] S3: Lamination: 100mg positive electrode composite powder → 20mg pure powder A → 100mg negative electrode composite powder. Spray with 2% ethanol aqueous solution.

[0078] S4: Cold sintering: Apply a pressure of 300MPa at 5MPa / s, heat to 100℃ at 15℃ / min, hold at the temperature and pressure for 8 minutes, and use the same pulse current as in Example 1.

[0079] S5: Heat treatment: Same as in Example 1. Battery module E3 is obtained.

[0080] Example 4: High-temperature stable system (using monomers with high reverse DA reaction temperature)

[0081] This invention provides an integrated solid-state battery module based on SiO2 aerogel powder, the preparation method of which includes the following steps:

[0082] S1: Preparation of Janus-structured SiO2 aerogel powder; D:

[0083] S1.1-S1.2: Same as Example 1.

[0084] S1.3: Immerse the aminated gel in 10 times the gel volume of a DMF solution containing 0.15 M anthracene-functionalized silane and 0.15 M maleimide-functionalized silane, and react at 65 °C for 28 hours.

[0085] S1.4-S1.5: Same as Example 1, to obtain powder D (reverse DA reaction temperature > 200℃).

[0086] Battery module fabrication:

[0087] S2: The formulation is the same as in Example 1, but powder D is used.

[0088] S3: Lamination is the same as in Example 1.

[0089] S4: Cold sintering: Same as Example 1.

[0090] S5: Heat treatment: Heat to 100℃ at 10℃ / min and hold for 30 minutes; then heat to 180℃ at 10℃ / min and hold for 3 minutes; cool with the furnace to obtain battery module E4.

[0091] Example 5: All-solid system (no additional liquid electrolyte)

[0092] This invention provides an integrated solid-state battery module based on SiO2 aerogel powder, such as... Figures 1-2 As shown, its preparation method includes the following steps:

[0093] S1: Preparation of powders with high ionic liquid content A+:

[0094] S1.1-S1.4: Same as Example 1.

[0095] S1.5: At 60℃ and 5Pa vacuum, the dry powder was immersed in 1.5M LiTFSI / [PYR13][TFSI] ionic liquid for 6 hours to ensure high pore saturation, thus obtaining powder A+.

[0096] Battery module fabrication:

[0097] S2-S3: Same as Example 1, using powder A+.

[0098] S4: Cold sintering: Same as Example 1.

[0099] S5: Heat treatment: Same as in Example 1.

[0100] S6: The formed battery module is not injected with any liquid electrolyte and is directly packaged into an all-solid-state battery module E5 in the drying room.

[0101] Example 6

[0102] This invention provides an integrated solid-state battery module based on SiO2 aerogel powder, such as... Figures 1-2 As shown, its preparation method includes the following steps:

[0103] S1: Preparation of Janus-structured SiO2 aerogel powder F:

[0104] S1.1: The steps are the same as in Example 1, but the amount of zirconium source (ZrOCl2·8H2O) added is adjusted to ZrO2 equivalent to 3% of the theoretical SiO2 mass.

[0105] S1.2-S1.5: Completely the same as in Example 1, to obtain powder F.

[0106] Battery module fabrication:

[0107] S2: The composite powder formulation is exactly the same as in Example 1, using powder F.

[0108] S3: The stacking method is the same as in Example 1.

[0109] S4: Cold sintering: Apply a pressure of 200MPa at a rate of 5MPa / s, heat to 80℃ at a rate of 10℃ / min, hold at the temperature and pressure for 15 minutes, and use the same pulse current as before.

[0110] S5: Heat treatment: Same as in Example 1, to obtain battery module E6.

[0111] Example 7

[0112] This invention provides an integrated solid-state battery module based on SiO2 aerogel powder, such as... Figures 1-2 As shown, its preparation method includes the following steps:

[0113] S1: Preparation of composite Janus structured SiO2 aerogel powder G:

[0114] S1.1-S1.4: Completely the same as in Example 1, to obtain Janus dry powder.

[0115] S1.5 (Modified): Before loading the ionic liquid, Janus dry powder and 2wt% boron nitride (BN) nanosheets are mixed at high speed in a mixer for 30 minutes to allow the BN nanosheets to physically adhere to the surface and pores of the aerogel particles.

[0116] S1.6: Subsequently, ionic liquid loading was performed as in Example 1 to obtain powder G.

[0117] Battery module fabrication:

[0118] S2-S5: All steps are exactly the same as in Example 1, except that powder A is replaced with powder G. Battery module E7 is obtained.

[0119] Example 8: Fabrication of battery modules by magnetic field-assisted cold sintering

[0120] The preparation process is basically the same as in Example 1, except that: Step S1.2 is optimized: After aging the composite wet gel at 40-60℃ for 24 hours, a mixed system of "5wt% APTES ethanol solution + Fe3O4 superparamagnetic nanoparticle dispersion" is prepared (Fe3O4 particle size 5-10nm, mass is 1-3% of the dry weight of the wet gel). The wet gel is immersed in the mixed system for 12 hours, during which ultrasonic dispersion is performed for 30 minutes (power 100W) to ensure that the Fe3O4 nanoparticles are uniformly dispersed and fixed in the gel network. Then, it is washed with ethanol 3 times. A constant magnetic field perpendicular to the plane of the mold is applied around the mold with a magnetic induction intensity of 0.5T, and the other parameters remain unchanged to obtain the battery module M.

[0121] Example 9: Preparation of battery modules by cold sintering assisted by pulsed current and magnetic field

[0122] The preparation process is basically the same as in Example 1, except that the same S1.2 step as in Example 8 is optimized. In the S4 cold sintering step, while applying a pulse current (with the same parameters as in Example 1), a magnetic field with a magnetic induction intensity of 0.3T perpendicular to the mold plane is applied to obtain battery module N.

[0123] Example 10: (DC electric field assisted cold sintering):

[0124] The preparation process is the same as in Example 1. In the S4 cold sintering step, no pulse current is applied, but a DC electric field perpendicular to the mold plane is applied with a field strength of 1kV / cm. The other parameters remain unchanged to obtain the battery module P.

[0125] Comparative Example 1: Aerogel Powder Battery without Dynamic Shell

[0126] Preparation method: The preparation process is basically the same as in Example 1, but steps S1.2 and S1.3 are omitted. That is, the aerogel powder contains only a rigid ZrO2@SiO2 core and ionic liquid, without a dynamic shell of DA bonds. Powder F-1 is obtained, and battery module C1 is prepared based on it.

[0127] Comparative Example 2: Aerogel Powder Battery without Rigid Core

[0128] Preparation method: The preparation process is basically the same as in Example 1, but no zirconium source is added in S1.1. That is, the powder is pure SiO2 aerogel + dynamic shell + ionic liquid. Powder F-2 is obtained, and battery module C2 is prepared.

[0129] Comparative Example 3: Battery manufactured using conventional hot-pressing process

[0130] Preparation method: Using powder A from Example 1, the powder was mixed according to the composite powder ratio of Example 1 and molded using a conventional hot pressing process (20 MPa, 150°C, 10 minutes) without transient liquid phase additives or pulsed current. The thermal repair steps remained unchanged. Battery module C3 was obtained.

[0131] Comparative Example 4: Battery without thermal repair steps

[0132] Preparation method: The preparation process is basically the same as in Example 1, but the heat treatment step S5 is completely omitted. Battery module C4 is obtained directly after cold sintering.

[0133] Comparative Example 5: A battery based on the physical mixing of ordinary aerogel

[0134] Preparation method:

[0135] Preparation of ordinary SiO2 aerogel powder (without zirconium source, without DA grafting).

[0136] The ordinary aerogel powder was directly physically mixed with Fu-MI monomer powder, positive and negative electrode materials, etc. (the mixing ratio was the same as in Example 1).

[0137] The subsequent layup, cold sintering, and heat treatment steps are the same as in Example 1. Battery module C5 is obtained.

[0138] Comparative Example 6: Commercial Liquid Electrolyte Batteries

[0139] Preparation method: Conventional NCM811 positive electrode and graphite negative electrode were prepared, and Celgard 2325 polyolefin separator was used. 1M LiPF6 in EC / DEC liquid electrolyte was injected and assembled into a coin cell C6.

[0140] Comparative Example 7: Cold-sintered battery without pulsed current assistance

[0141] Preparation method: The preparation process is exactly the same as in Example 1, except that in the S4 cold sintering step, no pulsed current is applied; only pressure and heating are retained. All other parameters remain unchanged. Battery module C7 is obtained.

[0142] Comparative Example 8: Traditional slurry coating - stacked cells (non-integrated structure)

[0143] Preparation method:

[0144] Powder A prepared in Example 1 was used.

[0145] Positive electrode sheet preparation: The positive electrode composite powder (with the same ratio as in Example 1) is mixed with NMP solvent to form a slurry, which is then coated onto aluminum foil, dried, and pressed into sheets.

[0146] Negative electrode sheet preparation: Negative electrode sheets are prepared using negative electrode composite powder in the same manner.

[0147] Electrolyte membrane fabrication: Pure powder A is mixed with 5wt% PVDF binder, NMP solvent is added to make a slurry, which is then coated onto a PET film, dried at 80℃ and peeled off, and then cold-pressed under 50MPa pressure (thickness 20μm).

[0148] Assembly: The positive electrode, electrolyte membrane, and negative electrode are mechanically stacked and placed in a mold. Hot pressing (50MPa, 100℃, 5 minutes) is then performed at a low pressure (e.g., 50MPa) and temperature to ensure interface contact. Cold sintering and subsequent two-step heat treatment are not performed. This yields battery module C8.

[0149] Performance testing

[0150] 1. Electrochemical impedance spectroscopy (EIS)

[0151] Method: A blocking electrode (such as stainless steel SS|electrolyte layer|SS) was used. Electrochemical impedance spectroscopy (EIS) was used to measure the bulk resistance and calculate the ionic conductivity by fitting the spectrum.

[0152] 2. Long-cycle performance test

[0153] Method: Assemble the battery modules into button cells and perform constant current charge-discharge cycle tests at a specific rate (e.g., 1C). Record the capacity retention rate at the 500th cycle.

[0154] 3. Heat abuse test (needle prick)

[0155] Method: The battery module was penetrated using a needle penetration tester, and the highest temperature on the battery surface was recorded using a thermal imager. The occurrence of fire or explosion was observed.

[0156] 4. Interface impedance growth test

[0157] Method: Before and after the cycle test, the battery was subjected to EIS test, and the percentage increase in interfacial impedance after the cycle was calculated by analyzing the spectrum.

[0158] The results are shown in Table 1 below:

[0159] Table 1 Summary of Performance Test Results

[0160]

[0161] As can be seen from the above, the basic system of this invention (E1) is significantly superior to all comparative examples (C1-C8) in terms of ionic conductivity, cycle life and thermal safety, which proves the effectiveness of the synergistic effect of "Janus structure aerogel", "cold sintering" and "thermal repair".

[0162] Self-healing function: The significant decrease in cycle life and thermal safety of C1 (without dynamic shell) proves that the self-healing of DA bond is crucial.

[0163] Mechanical support: C2 (without rigid core) has the lowest capacity retention rate and a sharp increase in interface impedance, proving that the rigid core is the basis for buffering stress.

[0164] Process originality: The overall disadvantages of C3 (conventional hot pressing) and C8 (traditional stacking) demonstrate the non-obviousness of the "cold sintering" and "integrated structure" design.

[0165] Importance of post-treatment: The poor cycling performance of C4 (without thermal repair) proves that heat treatment is indispensable for stabilizing the interface.

[0166] Significant optimization results: The optimized embodiments (such as E7, E8, E9) still show improved performance compared to E1, demonstrating the optimization potential and high technical barriers of the present invention.

[0167] Extreme safety performance: No fire or explosion was observed in the needle penetration tests of all embodiments of the present invention, with the highest temperature being <150℃. In contrast, C6 containing liquid electrolyte and the loosely structured traditional systems C3, C5, and C8 all experienced thermal runaway, demonstrating the revolutionary safety advantage of the present invention.

[0168] It should be noted that, for the sake of simplicity, the foregoing embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to the present invention. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0169] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on these embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still combine, add, delete, or otherwise adjust the features of the various embodiments of the present invention according to the circumstances without conflict or creative effort, thereby obtaining different technical solutions that do not fundamentally depart from the concept of the present invention. These technical solutions are also within the scope of protection of the present invention.

Claims

1. An integrated solid-state battery module based on SiO2 aerogel powder, comprising a positive electrode layer, a negative electrode layer, and a solid electrolyte layer therebetween, characterized in that, The solid electrolyte layer is composed of Janus structure SiO2 aerogel powder, and both the positive electrode layer and the negative electrode layer contain the Janus structure SiO2 aerogel powder. The Janus-structured SiO2 aerogel powder comprises a rigid core and a dynamic shell. The rigid core is formed by ZrO2 nanocrystal clusters and a SiO2 network through Zr-O-Si bonds. The dynamic shell is a cross-linked polymer layer containing dynamic covalent bonds covering the outer surface of the rigid core and the inner wall of the macropores. The dynamic covalent bonds are Diels-Alder bonds. The cross-linked polymer layer is formed by the polymerization of diene-functionalized silanes and dienophilic functionalized silanes through a Diels-Alder reaction.

2. The integrated solid-state battery module based on SiO2 aerogel powder as described in claim 1, characterized in that, The dienophilic functionalized silane is selected from at least one of furan functionalized silane and anthracene functionalized silane, and the dienophilic functionalized silane is selected from at least one of maleimide functionalized silane and norbornenediimide functionalized silane.

3. The integrated solid-state battery module based on SiO2 aerogel powder as described in claim 1, characterized in that, The three-dimensional pores of the Janus-structured SiO2 aerogel powder are loaded with a lithium salt-ionic liquid complex; the lithium salt is selected from at least one of lithium bis(trifluoromethanesulfonyl)imide and lithium bis(fluorosulfonyl)imide, and the ionic liquid is selected from at least one of 1-propyl-3-methylpyridine bis(trifluoromethanesulfonyl)imide and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide.

4. The integrated solid-state battery module based on SiO2 aerogel powder as described in claim 1, characterized in that, The positive and negative electrode layers are internally formed by a stress-supported framework consisting of rigid cores of Janus-structured SiO2 aerogel powder arranged in an oriented manner. The gaps between the framework are filled with electrode active materials and conductive agents. The orientation of the framework is conducive to ion transport perpendicular to the current collector direction.

5. The integrated solid-state battery module based on SiO2 aerogel powder as described in claim 1, characterized in that, The Janus structure SiO2 aerogel powder accounts for 10-20% of the mass in the positive electrode layer and 8-15% of the mass in the negative electrode layer; the ZrO2 nanocrystal cluster accounts for 3-8% of the mass in the rigid core.

6. A method for preparing an integrated solid-state battery module based on SiO2 aerogel powder as described in claim 1, characterized in that, Includes the following steps: S1: Preparation of Janus-structured SiO2 aerogel powder; S2: The powder obtained in S1 is mixed with positive electrode active material and conductive agent to prepare positive electrode composite powder, and mixed with negative electrode active material and conductive agent to prepare negative electrode composite powder; S3: The positive electrode composite powder → the Janus structure SiO2 aerogel powder as the electrolyte layer → the negative electrode composite powder are stacked in the mold in the following order: transient liquid phase auxiliary agent is sprayed evenly on the surface and between the layers of the stacked structure by spraying. S4: Apply 200-500MPa pressure to the stacked structure and perform cold sintering at 80-150℃, holding the temperature and pressure for 5-15 minutes to form an integrated battery blank; S5: The battery blank is placed in an inert atmosphere and subjected to two-step heat treatment: first, it is kept at a first temperature for 20-40 minutes to achieve interface fusion, and then it is kept at a second temperature higher than the first temperature for 2-5 minutes to achieve thermal trigger self-healing. The first temperature is 80-100℃, and the second temperature is not lower than the reverse reaction triggering temperature of the dynamic covalent bonds in the Janus structure SiO2 aerogel powder. After cooling, the stress-adaptive solid-state battery module is obtained.

7. The method for preparing an integrated solid-state battery module based on SiO2 aerogel powder as described in claim 6, characterized in that, The preparation of Janus-structured SiO2 aerogel powder in S1 includes the following steps: S1.1: Mix the silicon source with the solvent, add an acid catalyst to adjust the pH to 1-3, and perform pre-hydrolysis for 0.5-2 hours; then add the zirconium source, stir evenly, add an alkaline catalyst to adjust the pH to 4-6, and let it stand to gel, thus obtaining ZrO2@SiO2 composite wet gel. S1.2: The composite wet gel is aged at 40-60℃ for 12-36 hours and then immersed in an aminosilane solution for 10-16 hours to introduce amino functional groups. S1.3: Immerse the aminated gel in a diene-dienophile composite monomer solution and react at 50-70℃ for 18-30 hours to form a cross-linked polymer layer containing dynamic covalent bonds; S1.4: The gel was subjected to supercritical drying and ball milled to a particle size D50 = 2-5 μm to obtain Janus structure SiO2 aerogel dry powder; S1.5: Immerse the dry powder in a lithium salt-ionic liquid composite at 50-70℃ and a vacuum degree ≤10Pa for 2-6 hours, and then vacuum impregnate it with the loaded electrolyte.

8. The method for preparing an integrated solid-state battery module based on SiO2 aerogel powder as described in claim 6, characterized in that, The transient liquid phase auxiliary agent mentioned in S3 is selected from ethanol aqueous solution and / or dilute acetic acid solution, and the addition amount is 1-5% of the total mass of the powder; the volume ratio of the ethanol aqueous solution is 1:1-3, the mass concentration of the dilute acetic acid solution is 0.5-2%, the nozzle orifice diameter of the spray method is 0.1-0.5mm, and the spray pressure is 0.1-0.3MPa.

9. The method for preparing an integrated solid-state battery module based on SiO2 aerogel powder as described in claim 6, characterized in that, During the cold sintering process in S4, a pulsed current is applied with a pulsed current density of 10-50 mA / cm². 2 The pulse frequency is 1-5Hz and the duty cycle is 30-50%.

10. The method for preparing an integrated solid-state battery module based on SiO2 aerogel powder as described in claim 6, characterized in that, During the S4 cold sintering process, an external physical field perpendicular to the mold plane is simultaneously applied. The external physical field is either a magnetic field or a DC electric field. When it is a magnetic field, the magnetic induction intensity is 0.1-1.0T, and the ZrO2 nanocrystal clusters in the Janus structure SiO2 aerogel powder are modified with superparamagnetic nanoparticles. The mass of the superparamagnetic nanoparticles accounts for 1-3% of the Janus powder, and the particle size is 5-10nm. When it is a DC electric field, the field strength is 0.5-5kV / cm.

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