Solid electrolyte with bionic microstructure interface, preparation method of solid electrolyte and solid battery

Abstract

The invention provides a solid-state electrolyte with a bionic microstructure interface, a preparation method thereof and a solid-state battery, the solid-state electrolyte with the bionic microstructure interface comprises a solid-state electrolyte matrix, and at least one side surface of the solid-state electrolyte matrix is provided with a bionic microgroove structure. The bionic micro-groove structure is a tree-root-shaped fractal topology network structure, and comprises a main groove and a secondary groove which is branched and extends from the main groove; the ratio of the depth to the width of the main groove and the ratio of the depth to the width of the secondary groove are both larger than or equal to 0.3. The bionic micro-groove structure has a tree-root-shaped fractal structure, a three-dimensional microstructure of a multi-stage interconnection network is formed on the surface of the solid electrolyte, the solid-solid contact area can be effectively increased, the local current density can be reduced, and deposited lithium can be mechanically anchored, so that the purposes of low interface impedance and efficient dendritic crystal suppression are synchronously realized.

Description

Technical Field

[0001] This invention belongs to the field of solid-state battery technology, and relates to a solid electrolyte with a biomimetic microstructure interface, its preparation method, and a solid-state battery. Background Technology

[0002] Solid-state lithium batteries are considered a key development direction for next-generation energy storage devices due to their high safety and high energy density. However, solid-state batteries, especially those using lithium metal anodes, still face significant challenges in practical applications. Two interconnected core problems are poor solid-solid interface contact and lithium dendrite growth. On the one hand, the rigid contact between the solid electrolyte and the lithium metal anode results in a limited effective contact area, leading to excessively high interfacial impedance and potentially causing uneven local current density distribution. On the other hand, during battery cycling, lithium ions tend to deposit non-uniformly at interface defects or current concentration points, forming lithium dendrites. The continuous growth of dendrites not only consumes active material and reduces coulombic efficiency but may also puncture the electrolyte, leading to internal short-circuit failure.

[0003] To address these issues, existing technologies optimize the ionic conductivity and mechanical properties of the electrolyte bulk through elemental doping or composite polymers, or introduce a flexible interface layer between the electrolyte and the electrode to improve the physical contact between them and buffer volume changes. While these methods have made some progress, there is still room for improvement in certain aspects: for example, electrolyte component modification may be limited by the intrinsic properties of the material, and introducing an additional interface layer may increase process complexity and overall impedance, and long-term cycling stability needs to be verified.

[0004] Therefore, it is crucial to develop a solid electrolyte that can fundamentally improve interfacial contact, effectively guide uniform lithium-ion deposition, and is simple to process and easy to integrate. Summary of the Invention

[0005] The purpose of this invention is to provide a solid electrolyte with a biomimetic microstructure interface, a method for its preparation, and a solid battery. The biomimetic microgroove structure has a root-like fractal structure, forming a three-dimensional microstructure with a multi-level interconnected network on the surface of the solid electrolyte. This effectively increases the solid-solid contact area, reduces the local current density, and mechanically anchors the deposited lithium, thereby simultaneously achieving the goals of low interface impedance and efficient dendrite suppression.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a solid electrolyte with a biomimetic microstructure interface, the solid electrolyte with a biomimetic microstructure interface comprising a solid electrolyte matrix, wherein at least one side surface of the solid electrolyte matrix has a biomimetic microgroove structure, the biomimetic microgroove structure being a root-like fractal topology network structure, comprising a main groove and secondary grooves extending from the main groove.

[0008] The depth-to-width ratio of the main trench and the depth-to-width ratio of the secondary trench are both ≥0.3.

[0009] This invention addresses the problems of poor solid-solid interface contact and lithium dendrite growth in solid-state batteries. By creating a root-like biomimetic microtrench structure with grooves on at least one side of the solid electrolyte substrate, it efficiently guides and homogenizes lithium-ion flow, fundamentally eliminating current concentration points. Simultaneously, its multi-level spatial structure physically anchors and confines lithium deposition, restricting lithium growth within the trench network and effectively suppressing dendrite longitudinal penetration. Therefore, the root-like biomimetic microtrench structure of this invention can increase the contact area, reduce local current density, and mechanically anchor deposited lithium, thereby simultaneously achieving the goals of reducing interface impedance and efficiently suppressing dendrites. Furthermore, the depth-to-width ratio of both the main trench and the secondary trench is ≥0.3. By controlling the trench aspect ratio (depth-to-width ratio), a balance can be achieved between increasing the contact area, providing sufficient lithium-containing space, and maintaining structural mechanical stability, thereby improving the overall electrochemical performance of the solid-state battery.

[0010] The ratio of the depth to width of the main trench and the ratio of the depth to width of the secondary trench in this invention are ≥0.3. For example, they can be 0.3, 0.5, 0.7, 0.9, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5 or 5, but are not limited to the listed values. Other unlisted values ​​within the range are also applicable. Preferably, it is 0.3-5, and more preferably 0.5-2.

[0011] If the ratio of the depth to width of the main trench and the ratio of the depth to width of the secondary trench (i.e., aspect ratio) of the present invention is too small (e.g., <0.3), the biomimetic micro-trench structure will be too shallow and flat, weakening its guiding and redistribution effect on lithium ion flow and failing to provide an effective three-dimensional confinement space for lithium metal deposition. The physical constraint force to suppress dendrite growth will be insufficient, resulting in limited interface improvement effect. However, it should not be too large either. If it is too large (e.g., higher than 5), the biomimetic micro-trench structure will be too deep and narrow. During the cycling process, the repeated deposition and peeling of lithium metal will easily generate significant stress concentration in the trench, increasing the risk of local structural damage or peeling from the substrate. At the same time, deep and narrow trenches may not be conducive to the uniform transport of ions at the bottom of the trench and pose challenges to the hot pressing process, affecting the integrity and consistency of the structure.

[0012] Preferably, the depth ratio of the main trench to the secondary trench is (1.5-5):1, for example, it can be 1.5:1, 2:1, 3:1, 4:1 or 5:1, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0013] Preferably, the width ratio of the main trench to the secondary trench is (1.5-4):1, for example, it can be 1.5:1, 2:1, 3:1 or 4:1, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0014] In this invention, the depth of the main trench is greater than the depth of the secondary trench, and the width of the main trench is greater than the width of the secondary trench. By optimizing the size ratio of the main trench and the secondary trench, the efficient division of labor between the "trunk and capillary roots" in natural root systems is imitated. The main trench serves as the main channel for ion flow, while the secondary trench precisely controls the distribution of ions at the interface. This synergistic effect can further reduce the interface impedance, improve the interface ion transport efficiency and deposition uniformity. Simple uniform patterns cannot play the role of the root-like biomimetic microgrooves of this invention.

[0015] Preferably, the depth of the main trench is 20μm-50μm, for example, 20μm, 30μm, 40μm or 50μm, and the width is 30μm-100μm, for example, 30μm, 50μm, 70μm, 90μm or 100μm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0016] Preferably, the depth of the secondary trench is 5μm-30μm, for example, 5μm, 10μm, 15μm, 20μm, 25μm or 30μm, and the width is 10μm-50μm, for example, 10μm, 20μm, 30μm, 40μm or 50μm, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0017] Preferably, the biomimetic microgroove structure is filled with an ion-conducting functional material, which includes any one or a combination of at least two of the following: polymer electrolyte (e.g., a composite of polyethylene oxide (PEO) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)), lithium-containing inorganic salt (e.g., lithium fluoride (LiF) or lithium nitride (Li3N)), or soft ion conductor (e.g., Li3PS4 sulfide glass ceramic or Li3OCl halide superionic conductor).

[0018] The present invention can also fill the biomimetic microgroove structure with ion-conductive functional materials to further form a stable artificial interface phase, which can not only further reduce the interface impedance, but also buffer cyclic stress and suppress side reactions, thereby upgrading the simple physical structure advantage to physical-chemical synergistic stability and improving long-term cycling performance.

[0019] Preferably, the secondary trench continues to branch out into more trenches.

[0020] This invention includes not only the two-level structure of primary trench and secondary trench, but also the secondary trenches that continue to branch and extend, which can also continue to branch and extend, forming a multi-level topology network structure.

[0021] Preferably, the thickness of the solid electrolyte matrix is ​​300μm-500μm, for example, it can be 300μm, 350μm, 400μm, 450μm or 500μm, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0022] Preferably, the solid electrolyte matrix includes a sulfide solid electrolyte, an oxide solid electrolyte, or a polymer solid electrolyte.

[0023] In a second aspect, the present invention provides a method for preparing a solid electrolyte with a biomimetic microstructure interface as described in the first aspect, the method comprising the following steps:

[0024] After hot pressing a solid electrolyte sheet with an embossing roller having raised microstructures, the sheet is cooled and demolded to obtain the solid electrolyte with the biomimetic microstructure interface, wherein the raised microstructures and the biomimetic microgroove structure are complementary.

[0025] The preparation method described in this invention is based on a mature hot pressing process, which can form the key structure in one step. It is easy to integrate into existing production lines. Furthermore, the method has high versatility and can be applied to various solid electrolyte systems such as sulfides, oxides, and polymers, thus possessing good versatility.

[0026] Specifically, the preparation method of the present invention includes: providing an embossing roller having a raised pattern on its surface that is complementary to the microgroove structure; placing a solid electrolyte sheet between the embossing roller and a support roller; and hot pressing to transfer the raised pattern onto the surface of the solid electrolyte sheet to form a root-like microgroove structure.

[0027] Preferably, the hot pressing temperature is 50℃-200℃, for example, 50℃, 100℃, 150℃ or 200℃, the pressure is 0.1MPa-5MPa, for example, 0.1MPa, 1.1MPa, 2.1MPa, 3.1MPa, 4.1MPa or 5MPa, and the holding time is 1min-30min, for example, 5min, 10min, 15min, 20min, 25min or 30min, but not limited to the listed values, other unlisted values ​​within the range are also applicable.

[0028] Preferably, the preparation method further includes the following steps: filling the biomimetic microgroove structure with an ion-conductive functional material slurry and performing a curing treatment.

[0029] Thirdly, the present invention provides a solid-state battery, the solid-state battery comprising a positive electrode, a negative electrode, and a solid electrolyte having a biomimetic microstructure interface as described in the first aspect, disposed between the positive electrode and the negative electrode.

[0030] When the solid electrolyte with biomimetic microstructure interface described in this invention has a biomimetic microgroove structure on only one side, the side with the biomimetic microgroove structure faces the negative electrode.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] This invention addresses the problems of poor solid-solid interface contact and lithium dendrite growth in solid-state batteries. By creating a root-like biomimetic microtrench structure with grooves on at least one side of the solid electrolyte substrate, it efficiently guides and homogenizes lithium-ion flow, fundamentally eliminating current concentration points. Simultaneously, its multi-level spatial structure physically anchors and confines lithium deposition, restricting lithium growth within the trench network and effectively suppressing dendrite longitudinal penetration. Therefore, the root-like biomimetic microtrench structure of this invention can increase the contact area, reduce local current density, and mechanically anchor deposited lithium, thereby simultaneously achieving the goals of reducing interface impedance and efficiently suppressing dendrites. Furthermore, the depth-to-width ratio of the biomimetic microtrench structure of this invention is ≥0.3. By controlling the trench aspect ratio (depth-to-width ratio), a balance can be achieved between increasing the contact area, providing sufficient lithium-containing space, and maintaining structural mechanical stability, thereby improving the overall electrochemical performance of the solid-state battery. Detailed Implementation

[0033] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0034] Example 1

[0035] This embodiment provides a solid electrolyte with a biomimetic microstructure interface. The solid electrolyte with a biomimetic microstructure interface includes a solid electrolyte substrate (16 mm in diameter, 500 μm in thickness, and made of Li6PS5Cl). One side surface of the solid electrolyte substrate has a biomimetic microgroove structure. The biomimetic microgroove structure is a root-like fractal topology network structure, including a main groove and secondary grooves extending from the main groove.

[0036] The depth-to-width ratio of both the main trench and the secondary trench is 0.75;

[0037] The depth of the main trench and the depth of the secondary trench are both 30 μm, and the depth ratio of the main trench to the secondary trench is 1:1.

[0038] The width of the main trench and the width of the secondary trench are both 40 μm, and the width ratio of the main trench to the secondary trench is 1:1.

[0039] The preparation method of the solid electrolyte with the biomimetic microstructure interface includes the following steps:

[0040] (1) 45# steel is selected to prepare the embossing roller, and the surface is processed with tree root-like raised patterns. The patterns are distributed in a multi-level fractal pattern, which complements the biomimetic microgroove structure.

[0041] (2) The solid electrolyte disc is fed into the hot pressing equipment and placed between the embossing roller preheated to 120°C and the flat silicone support roller. A pressure of 2MPa is applied and the pressure is maintained for 5 minutes.

[0042] (3) After depressurization, the sample is cooled to room temperature and removed from the roller to obtain the solid electrolyte with the biomimetic microstructure interface.

[0043] Example 2

[0044] This embodiment provides a solid electrolyte with a biomimetic microstructure interface. The solid electrolyte with a biomimetic microstructure interface includes a solid electrolyte matrix (16 mm in diameter, 300 μm in thickness, and made of Li7La3Zr2O). 12 The solid electrolyte substrate has a biomimetic microgroove structure on one side surface. The biomimetic microgroove structure is a root-like fractal topology network structure, including a main groove and secondary grooves extending from the main groove.

[0045] The depth-to-width ratio of both the main trench and the secondary trench is 0.67.

[0046] The depth of the main trench and the depth of the secondary trench are both 20 μm, and the depth ratio of the main trench to the secondary trench is 1:1.

[0047] The width of the main trench and the width of the secondary trench are both 30 μm, and the width ratio of the main trench to the secondary trench is 1:1.

[0048] The preparation method of the solid electrolyte with the biomimetic microstructure interface includes the following steps:

[0049] (1) Alumina ceramic is selected to prepare the embossing roller, and its surface is processed with tree root-like raised patterns. The patterns are distributed in a multi-level fractal pattern, which complements the biomimetic microgroove structure.

[0050] (2) The solid electrolyte disc is fed into the hot pressing equipment and placed between the embossing roller preheated to 150°C and the flat silicone support roller. A pressure of 3MPa is applied and the pressure is maintained for 3 minutes.

[0051] (3) After depressurization, the sample is cooled to room temperature and removed from the roller to obtain the solid electrolyte with the biomimetic microstructure interface.

[0052] Example 3

[0053] This embodiment provides a solid electrolyte with a biomimetic microstructure interface. The solid electrolyte with a biomimetic microstructure interface is the same as that in Embodiment 1, except that the depth of the main trench and the depth of the secondary trench are both 20 μm, the width of the main trench and the width of the secondary trench are both 40 μm, and the depth-to-width ratio of the main trench and the secondary trench is 0.5.

[0054] Example 4

[0055] This embodiment provides a solid electrolyte with a biomimetic microstructure interface. The solid electrolyte with a biomimetic microstructure interface is the same as that in Embodiment 1, except that the depth of the main trench and the depth of the secondary trench are both 40 μm, the width of the main trench and the width of the secondary trench are both 20 μm, and the depth-to-width ratio of the main trench and the secondary trench are both 2.

[0056] Example 5

[0057] This embodiment provides a solid electrolyte with a biomimetic microstructure interface. The solid electrolyte with a biomimetic microstructure interface is the same as that in Embodiment 1, except that the depth of the main trench and the depth of the secondary trench are both 15 μm, the width of the main trench and the width of the secondary trench are both 50 μm, and the depth-to-width ratio of the main trench and the secondary trench is 0.3.

[0058] Example 6

[0059] This embodiment provides a solid electrolyte with a biomimetic microstructure interface. The solid electrolyte with a biomimetic microstructure interface is the same as that in Embodiment 1, except that the depth of the main trench and the depth of the secondary trench are both 45 μm, the width of the main trench and the width of the secondary trench are both 15 μm, and the depth-to-width ratio of the main trench and the secondary trench are both 3.

[0060] Example 7

[0061] This embodiment provides a solid electrolyte with a biomimetic microstructure interface. The solid electrolyte with a biomimetic microstructure interface is the same as that in Embodiment 1, except that the depth of the main trench and the depth of the secondary trench are both 50 μm, the width of the main trench and the width of the secondary trench are both 10 μm, and the depth-to-width ratio of the main trench and the secondary trench are both 5.

[0062] Example 8

[0063] This embodiment provides a solid electrolyte with a biomimetic microstructure interface. Except for the biomimetic microgroove structure being filled with a polymer electrolyte (including PEO and LiTFSI in a mass ratio of 80:20), the solid electrolyte with the biomimetic microstructure interface is the same as that in Embodiment 1.

[0064] The preparation method of the solid electrolyte with biomimetic microstructure interface includes the following steps:

[0065] A PEO-LiTFSI polymer electrolyte slurry was prepared and coated onto the surface of the solid electrolyte with a biomimetic microstructure interface described in Example 1 (the surface with a biomimetic microstructure). After the grooves were filled by capillary action, the slurry was dried and cured under vacuum at 60°C to obtain the solid electrolyte with a biomimetic microstructure interface described in this example.

[0066] Example 9

[0067] This embodiment provides a solid electrolyte with a biomimetic microstructure interface. The solid electrolyte with the biomimetic microstructure interface is the same as in Embodiment 1 except that the width of the main trench is 60 μm and the depth is 42 μm, and the width of the secondary trench is 25 μm and the depth is 17.5 μm, so that the depth ratio of the main trench to the secondary trench is 2.4:1 and the width ratio is 2.4:1. The depth-to-width ratio of the main trench and the secondary trench is 0.7.

[0068] Example 10

[0069] This embodiment provides a solid electrolyte with a biomimetic microstructure interface. The solid electrolyte with the biomimetic microstructure interface is the same as in Embodiment 1, except that the width of the main trench is 80 μm and the depth is 56 μm, and the width of the secondary trench is 15 μm and the depth is 8 μm, so that the depth ratio of the main trench to the secondary trench is 7:1 and the width ratio is 5.3:1, the depth-to-width ratio of the main trench is 0.7 and the depth-to-width ratio of the secondary trench is 0.53.

[0070] Comparative Example 1

[0071] This comparative example provides a solid electrolyte with a diameter of 16 mm, a thickness of 500 μm, and is made of Li6PS5Cl, which does not have a biomimetic microgroove structure.

[0072] Comparative Example 2

[0073] This comparative example provides a solid electrolyte, which is the same as that in Example 1 except that it does not contain secondary trenches, i.e., the main trenches do not branch and extend.

[0074] Comparative Example 3

[0075] This comparative example provides a solid electrolyte, which is the same as in Example 1 except that the depth of the main trench and the depth of the secondary trench are both 10 μm, the width of the main trench and the width of the secondary trench are both 50 μm, and the depth-to-width ratio of the main trench and the secondary trench is 0.2.

[0076] The solid electrolytes obtained in the above embodiments and comparative examples were assembled into Li|solid electrolyte|Li symmetric cells. The interfacial impedance, critical current density, and cycle performance of the symmetric cells were tested using the following methods:

[0077] (1) Interfacial impedance test: An electrochemical workstation (such as Bio-Logic VMP3) was used in a glove box (water oxygen content <0.1 ppm); electrochemical impedance spectroscopy (EIS) was performed at room temperature (25℃) at open circuit potential; the frequency range was 1MHz to 0.1Hz, and the AC amplitude was 10mV; by fitting a semicircle in the high-frequency region, the sum of the bulk resistance and the interfacial resistance was obtained, and the interfacial impedance per unit area (Ω·cm) was calculated. 2 ).

[0078] (2) Critical current density test: from 0.1 mA / cm 2 Starting with a specific current density, the current density increases by 0.1 mA / cm² every 10 cycles (one hour for each charge / discharge cycle). 2When the battery voltage experiences drastic fluctuations or a momentary short circuit (voltage drops sharply to near 0V) during charging and discharging, the current density of the previous step is recorded as the critical current density (mA / cm²) of the battery. 2 ).

[0079] (3) At a fixed current density (e.g., 0.2 mA / cm²) 2 The battery was subjected to constant current charge-discharge cycles, with each cycle consisting of 1 hour of charging (lithium deposition) and 1 hour of discharging (lithium stripping). The battery voltage change curve over time (or number of cycles) was recorded. The test was terminated when the battery experienced an internal short circuit (sudden voltage drop and sustained proximity to 0V) or when the overpotential exceeded a preset cutoff value (e.g., 1V). The number of cycles or time (in hours) elapsed from start to finish was recorded as the cycle life.

[0080] The depth-to-width ratio, the depth-to-width ratio of the main trench and the secondary trench, the interface impedance, critical current density, and cycle life obtained from the above embodiments and Comparative Example 1 are shown in Table 1:

[0081] Table 1

[0082]

[0083] As can be seen from Table 1 above:

[0084] As can be seen from Example 1 and Comparative Example 1, the performance of Example 1 is far superior to that of Comparative Example 1, indicating that the biomimetic microstructure described in this invention is highly efficient in improving the interface and suppressing dendrites. As can be seen from Example 1 and Comparative Example 2, if only the main trench structure is included, the "trunk transport and capillary absorption" function of the root-like microstructure cannot be fully utilized, resulting in a decrease in the performance of the solid-state battery. As can be seen from Example 1 and Example 2, this invention is applicable to both sulfide solid electrolytes and oxide solid electrolytes. As can be seen from Example 1, Examples 4-5, Examples 6-7 and Comparative Example 3, the biomimetic microgroove structure described in this invention... The depth-to-width ratio needs to be ≥0.3 to ensure a balance between multiple performance characteristics. The depth-to-width ratio of the biomimetic microgroove structure is preferably 0.3-5, and more preferably 0.5-2. As can be seen from Examples 1 and 8, after filling the groove with polymer electrolyte, the interfacial impedance can be further reduced and the cycle life can be significantly extended. As can be seen from Examples 1, 9 and 10, the size of the main groove is preferably larger than that of the secondary groove, which can further optimize the performance and enable the main groove and the secondary groove to achieve the division of labor of "main trunk transport and capillary root absorption". However, the size of the main groove and the secondary groove should not differ too much.

[0085] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A solid electrolyte with a biomimetic microstructure interface, characterized in that, The solid electrolyte with a biomimetic microstructure interface includes a solid electrolyte matrix, and at least one side surface of the solid electrolyte matrix has a biomimetic microgroove structure. The biomimetic microgroove structure is a root-like fractal topology network structure, including a main groove and secondary grooves extending from the main groove. The ratio of the depth to the width of the main trench and the ratio of the depth to the width of the secondary trench are both ≥0.

3.

2. The solid electrolyte with a biomimetic microstructure interface according to claim 1, characterized in that, The depth-to-width ratio of the main trench is 0.3-5; And / or, the depth-to-width ratio of the secondary trench is 0.3-5.

3. The solid electrolyte with a biomimetic microstructure interface according to claim 2, characterized in that, The depth-to-width ratio of the main trench is 0.5-2; And / or, the depth-to-width ratio of the secondary trench is 0.5-2.

4. The solid electrolyte with a biomimetic microstructure interface according to claim 1 or 2, characterized in that, The depth ratio of the main trench to the secondary trench is (1.5-5):1; And / or, the width ratio of the main trench to the secondary trench is (1.5-4):1; And / or, the depth of the main trench is 20μm-50μm and the width is 30μm-100μm; And / or, the depth of the secondary trench is 5μm-30μm and the width is 10μm-50μm.

5. The solid electrolyte with a biomimetic microstructure interface according to claim 1 or 2, characterized in that, The biomimetic microgroove structure is filled with an ion-conducting functional material, which includes any one or a combination of at least two of polymer electrolytes, lithium-containing inorganic salts, or soft ion conductors.

6. The solid electrolyte with a biomimetic microstructure interface according to claim 1 or 2, characterized in that, The secondary trench continues to branch out and extend into other trenches.

7. The solid electrolyte with a biomimetic microstructure interface according to claim 1 or 2, characterized in that, The thickness of the solid electrolyte substrate is 300μm-500μm; And / or, the solid electrolyte matrix includes a sulfide solid electrolyte, an oxide solid electrolyte, or a polymer solid electrolyte.

8. A method for preparing a solid electrolyte with a biomimetic microstructure interface as described in any one of claims 1-7, characterized in that, The preparation method includes the following steps: After hot pressing a solid electrolyte sheet with an embossing roller having raised microstructures, the sheet is cooled and demolded to obtain the solid electrolyte with the biomimetic microstructure interface, wherein the raised microstructures and the biomimetic microgroove structure are complementary.

9. The preparation method according to claim 8, characterized in that, The hot pressing temperature is 50℃-200℃, the pressure is 0.1MPa-5MPa, and the holding time is 1min-30min; And / or, the preparation method further includes the following steps: filling the biomimetic microgroove structure with an ion-conductive functional material slurry and performing a curing treatment.

10. A solid-state battery, characterized in that, The solid-state battery includes a positive electrode, a negative electrode, and a solid electrolyte having a biomimetic microstructure interface as described in any one of claims 1-7, disposed between the positive electrode and the negative electrode.

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