An all-solid-state battery cell having a thermal expansion stress-induced irreversible destruction mechanism of a solid-state electrolyte layer

Abstract

This invention discloses an all-solid-state battery cell with a thermal expansion stress-induced irreversible damage mechanism for the solid electrolyte layer. The all-solid-state battery cell includes a positive electrode layer, a negative electrode layer, and a solid electrolyte layer stacked between the positive and negative electrode layers. A thermal expansion stress-induced material with a specific threshold temperature is disposed within the solid electrolyte layer and / or at the electrode contact interface. By disposing of this thermal expansion stress-induced material with a specific threshold temperature within the solid electrolyte layer and / or at the electrode contact interface, the all-solid-state battery cell causes a rapid volume expansion when the specific threshold temperature is reached, leading to the fracture of adjacent solid electrolyte layers. Unlike the separator-closing function of traditional liquid lithium-ion batteries, this mechanism effectively solves the unique technical challenges of all-solid-state batteries by directly physically disrupting the solid ion conduction pathway that is independent of liquid components.

Description

Technical Field

[0001] This invention relates to the field of all-solid-state battery (ASSB) technology, and in particular to an all-solid-state battery cell with a thermal expansion stress-induced irreversible damage mechanism of the solid electrolyte layer. This all-solid-state battery cell is a structure that achieves high safety at the battery cell level. This structure can detect local abnormal heating inside the battery (early stage of thermal runaway) and permanently sever the ion conduction path of the solid electrolyte layer by physical means. Background Technology

[0002] Lithium-ion batteries are classified into liquid lithium-ion batteries, semi-solid-state batteries, and all-solid-state batteries. All-solid-state batteries are a new type of battery that uses a solid electrolyte instead of a liquid electrolyte. In traditional liquid lithium-ion batteries, thermal runaway is typically prevented by incorporating a shutdown function in the separator or by using a battery management system (BMS). However, all-solid-state batteries, lacking a liquid electrolyte, cannot utilize these traditional methods. Furthermore, all-solid-state batteries also suffer from internal short circuits and localized heating caused by lithium dendrite growth and interface reactions, potentially leading to internal thermal runaway. Currently, no internal mechanism has been found in existing technology that can safely and irreversibly shut down the battery when it heats up. Summary of the Invention

[0003] To overcome the shortcomings of the prior art, the present invention provides an all-solid-state battery cell with a thermal expansion stress-induced irreversible damage mechanism of the solid electrolyte layer, so as to solve the above-mentioned problems of the traditional technology.

[0004] This invention is achieved using the following technical solution: An all-solid-state battery cell with a thermal expansion stress-induced irreversible damage mechanism of the solid electrolyte layer includes a positive electrode layer, a negative electrode layer, and a solid electrolyte layer stacked between the positive electrode layer and the negative electrode layer. A thermal expansion damage-inducing material with a specific threshold temperature is disposed inside the solid electrolyte layer and / or at the electrode contact interface. When the specific threshold temperature is reached, the thermal expansion damage-inducing material undergoes rapid volume expansion, causing the adjacent solid electrolyte layer to fracture.

[0005] Furthermore, the average coefficient of thermal expansion of the thermal expansion-induced material is at least three times higher than the average coefficient of thermal expansion of the adjacent solid electrolyte layer.

[0006] Furthermore, the average coefficient of thermal expansion of the thermal expansion-induced material is 4-10 times that of the average coefficient of thermal expansion of the adjacent solid electrolyte layer.

[0007] Furthermore, the average coefficient of thermal expansion of the thermal expansion-induced failure material is (30-100)×10⁻⁶. -6 / K, the average thermal expansion coefficient of the solid electrolyte layer is (10-30)×10 -6 / K.

[0008] Furthermore, the specific threshold temperature ranges from 150°C to 300°C.

[0009] Furthermore, the thermal expansion failure inducing material is a composite ceramic particle with an average particle size of 1-4 μm.

[0010] Furthermore, the composite ceramic particles are one or more of TiC-Ni composite hollow ceramic microspheres, Cu-SiC composite hollow ceramic microspheres, and SiC-Al composite hollow ceramic microspheres.

[0011] Furthermore, when the thermal expansion failure inducing material is disposed inside the solid electrolyte layer, the thermal expansion failure inducing material is uniformly dispersed in the solid electrolyte layer at a ratio of (3-10)V / V%; when the thermal expansion failure inducing material is disposed at the electrode contact interface of the solid electrolyte layer, the thickness of the thermal expansion failure inducing material is 0.01-0.1 times the thickness of the solid electrolyte layer.

[0012] Furthermore, the thermal expansion failure inducing material is a thermally responsive ionic insulating material, and the thermally responsive ionic insulating material is a composite solid electrolyte.

[0013] Furthermore, a stress concentration structure for concentrating thermal expansion stress is provided around the thermal expansion failure-inducing material, wherein the stress concentration structure is a sharpened structural edge or a specific defect layer.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The all-solid-state battery cell of the present invention provides a thermal expansion-induced material with a specific threshold temperature inside the solid electrolyte layer and / or at the electrode contact interface. When the specific threshold temperature is reached, the material undergoes a rapid volume expansion, causing the adjacent solid electrolyte layer to break. Unlike the separator shut-off function of traditional liquid lithium-ion batteries, this mechanism effectively solves the unique technical problems of all-solid-state batteries by directly physically destroying the solid ion conduction path that does not depend on the liquid components.

[0015] 2. When abnormal heating occurs inside the battery, the all-solid-state battery cell of the present invention does not need to rely on external systems such as BMS. The battery cell itself can quickly prevent the chain reaction of thermal runaway. Compared with BMS electronic detection or module-level cooling, it can more quickly and reliably isolate the chain reaction of thermal runaway of the entire battery pack. This mechanism ensures that once the circuit breaker is activated, it will not be re-conducted even if the temperature drops, thereby maintaining a permanent open circuit state.

[0016] 3. The all-solid-state battery cell of the present invention combines thermal expansion failure inducing materials and stress concentration structures, enabling its thermal expansion failure inducing structure to form irreversible physical cracks more quickly and reliably in the solid electrolyte layer, permanently cutting off the ion conduction path of the solid electrolyte layer and completely preventing the battery cell from restarting. Attached Figure Description

[0017] Figure 1 This is a schematic cross-sectional view of the basic structure of the all-solid-state battery cell of the present invention; Figure 2 This is a schematic cross-sectional view of the operating principle of the circuit breaker mechanism involved in Embodiment 1 of the present invention during the initial stage of thermal runaway; Figure 3 This is a schematic cross-sectional view of the permanent ion channel disconnection state after the circuit breaker mechanism involved in Embodiment 1 of the present invention is activated. Figure 4 This is a cross-sectional view of the stress concentration structure in Embodiment 2 of the present invention; Figure 5 This is a cross-sectional view of the mode in Embodiment 3 of the present invention, which uses a thermally responsive ion insulating layer to achieve functional barrier. Figure 6 This is a schematic diagram of the operation and reset of the reversible thermally responsive material in Comparative Example 2 of the present invention.

[0018] In the figure: 100, all-solid-state battery cell; 110, positive electrode layer; 120, solid electrolyte layer; 130, negative electrode layer; 140, thermal expansion failure-inducing material; 150, shear stress; 160, first through-crack; 170, second through-crack; 190, stress concentration point; 110a, periodic nanopillar structure; 200, composite solid electrolyte; 220, lithium-ion conduction pathway functionally blocked route; 300, reversible thermal expansion material; 320, lithium-ion conduction pathway reconstruction route. Detailed Implementation

[0019] To address the risk of thermal runaway in all-solid-state batteries caused by internal short circuits and localized heating due to lithium dendrite growth and interface reactions, this invention provides an all-solid-state battery cell with a thermal expansion stress-induced irreversible damage mechanism for the solid electrolyte layer. When abnormal heating occurs inside the battery, it can quickly prevent the chain reaction of thermal runaway (domino effect) without relying on external systems such as BMS. This ensures that once the circuit breaker is activated, it will not re-conduct even if the temperature drops, thus maintaining a permanent open circuit state.

[0020] Specifically, such as Figure 1As shown, the all-solid-state battery cell 100 includes a positive electrode layer 110, a negative electrode layer 130, and a solid electrolyte layer 120 stacked between the positive electrode layer 110 and the negative electrode layer 130. A thermal expansion induction material 140 with a specific threshold temperature is disposed inside the solid electrolyte layer 120 and / or at the electrode contact interface. When the specific threshold temperature is reached, the thermal expansion induction material 140 undergoes rapid volume expansion, causing the adjacent solid electrolyte layer 120 to fracture. The expansion of the thermal expansion induction material 140 induces irreversible structural damage to the adjacent solid electrolyte layer 120, thereby achieving the effect of permanently blocking the lithium-ion conduction path.

[0021] In this embodiment, the solid electrolyte layer 120 is an inorganic solid electrolyte layer 120 or an organic solid electrolyte layer 120. The inorganic solid electrolyte layer 120 includes sulfide-based solid electrolytes, oxide-based solid electrolytes, and halide-based solid electrolytes. The sulfide-based solid electrolytes include lithium germanium phosphorus sulfide (LiGPS) type (such as Li...). 10 GeP2S 12 ), lithium silicon phosphorus sulfur chloride (LiSiPSCl) type (such as Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 Lithium phosphorus sulfide chlorine (LiPSCl) type (such as Li6PS5Cl) and lithium phosphorus sulfide (LiPS) type (such as Li7P3S) 11 Oxide-based solid electrolytes include garnet-type electrolytes (lithium lanthanum zirconium oxide LLZO, such as Li7La3Zr2O). 12 ), perovskite type (lithium lanthanum titanium oxide LLTO such as Li), 0.33 La 0.557 TiO3), NASICON type (lithium aluminum germanium phosphate LAGP such as Li1.5Al0.5Ge1.5(PO4)3) and lithium aluminum titanium phosphate LATP such as Li 1.5 Al 0.5 Ti 1.5(PO4)3), amorphous (LiPON); halide-based solid electrolytes include chloride systems (such as Li3MCl6 (M=Sc, Y, La, etc.)Li2ZnCl4 (spinel structure)), bromide systems (such as Li3YBr6), iodide systems (such as Li4YI7), fluoride systems (such as Na2ZrCl6), and composite / derivative systems (such as halide oxides (such as Li3OCl), defective anti-spinel structures (such as Li2MCl4)). The organic solid electrolyte layer 120 is a polymer-based solid electrolyte, such as polyethylene oxide (PEO) and its derivatives, polyvinylidene fluoride (PVDF) and its copolymers, polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), polypropylene oxide (PPO), and molecular organic solid electrolytes (MOSSEs).

[0022] In this embodiment, the specific threshold temperature range is 150℃~300℃, such as 150℃, 180℃, 180℃, 200℃, 220℃, 240℃, 260℃, 280℃, 300℃, etc.

[0023] In some embodiments, the average coefficient of thermal expansion of the thermal expansion failure-inducing material 140 is at least three times higher than the average coefficient of thermal expansion of the adjacent solid electrolyte layer 120. Preferably, the average coefficient of thermal expansion of the thermal expansion failure-inducing material 140 is 4-10 times the average coefficient of thermal expansion of the adjacent solid electrolyte layer 120, such as 4, 5, 6, 7, 8, 9, 10, etc. In this embodiment, the average coefficient of thermal expansion of the thermal expansion failure-inducing material 140 is (30-100) × 10⁻¹⁰. -6 / K, such as 30×10 -6 / K、40×10 -6 / K、50×10 -6 / K、60×10 -6 / K、70×10 -6 / K、80×10 -6 / K、90×10 -6 / K、100×10 -6 / K etc., the average thermal expansion coefficient of the solid electrolyte layer 120 is (10-30)×10 -6 / K, such as 10×10 -6 / K、20×10 -6 / K、30×10 -6 / K, etc.; Optionally, the thermal expansion failure inducing material 140 is, but is not limited to, composite ceramic particles, with an average particle size of 1-4 μm, such as 1 μm, 2 μm, 3 μm, 4 μm, etc. In other embodiments, the thermal expansion failure inducing material 140 can also be polyethylene (PE), polypropylene (PP), etc. Due to the large variety, they will not be described in detail here. Optionally, the composite ceramic particles are, but are not limited to, one or more of TiC-Ni composite hollow ceramic microspheres, Cu-SiC composite hollow ceramic microspheres, and SiC-Al composite hollow ceramic microspheres. When the thermal expansion failure inducing material 140 is disposed inside the solid electrolyte layer 120, the thermal expansion failure inducing material 140 is uniformly dispersed in the solid electrolyte layer 120 at a concentration of (3-10) V / V%, such as 3V / V%, 4V / V%, 5V / V%, 6V / V%, 7V / V%, 8V / V%, 9V / V%, 10V / V%, etc. When the thermal expansion failure inducing material 140 is disposed at the electrode contact interface of the solid electrolyte layer 120, the thickness of the thermal expansion failure inducing material 140 is 0.01-0.1 times the thickness of the solid electrolyte layer 120, such as 0.01, 0.03, 0.05, 0.07, 0.08, 0.1, etc.

[0024] In this embodiment, the positive electrode layer 110 is a high-nickel ternary lithium (such as an NCM-based positive electrode) or a lithium-rich manganese-based (such as Li2MnO3·LiMO2, LiNi) electrode. 0.5 Mn 1.5 One of O4), spinel lithium nickel manganese oxide, and the negative electrode layer 130 is a silicon-carbon negative electrode, a silicon-oxygen negative electrode, a lithium metal negative electrode, or a lithium titanate negative electrode (Li4Ti5O). 12 One of them.

[0025] In other embodiments, the thermal expansion failure inducing material 140 is a thermally responsive ionic insulating material, which is, but is not limited to, a composite solid electrolyte 200. This material undergoes a phase transition at a threshold temperature, resulting in an irreversible and extreme reduction in ionic conductivity. For example, a composite solid electrolyte 200 composed of a metal oxide and a lithium salt in a mass ratio of (5-30):(70-95), wherein the metal oxide is, but is not limited to, LLZO or Al2O3, and the lithium salt is, but is not limited to, LiPF6 or LiClO4.

[0026] In this embodiment, a stress concentration structure is provided around the thermal expansion failure-inducing material 140 to concentrate the thermal expansion stress. The stress concentration structure is a sharpened structural edge or a specific defect layer. When the thermal expansion failure-inducing material 140 expands, this structure can intentionally induce crack generation, thereby causing irreversible structural damage. The sharpened structural edge is a periodic nanopillar structure, a micron-level sharp corner, or a structure with a very small radius of curvature (<10μm). The angle of the micron-level sharp corner is 30°-60°, and the radius of curvature is controlled within the range of 1-5μm. The height of the periodic nanopillar structure is 1-5μm, and the spacing is 1-5μm. The specific defect layer is constructed by using doped pore-forming agents (such as ammonium carbonate ((NH4)2CO3), ammonium bicarbonate (NH4HCO3), ammonium chloride (NH4Cl), etc.) to construct a uniformly distributed array of nano-sized pores (pore size 50-200 nm).

[0027] The present invention will now be further described in conjunction with specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0028] Example 1: Cracks induced by thermally expanded ceramic particles This all-solid-state battery cell consists of an NCM-based positive electrode layer 110, a lithium metal negative electrode layer 130, and a sulfide-based solid electrolyte layer 120 (SSC layer) (using Li). 10 GeP2S 12 The SSC layer is composed of a stacked all-solid-state battery cell 100 with a thickness of 50 μm. The SSC layer contains a thermal expansion-induced failure material 140, which is a TiC-Ni composite hollow ceramic microsphere (average particle size 2 μm, coefficient of thermal expansion 100 × 10⁻⁶) that begins to expand at a threshold temperature of 180 °C. -6 / K), uniformly dispersed in the SSC layer volume at a concentration of 3% by volume. The coefficient of thermal expansion of SSC itself is 10 × 10. -6 / K.

[0029] Its preparation method is as follows: 1. The sulfur-based solid electrolyte material powder and the above-mentioned thermal expansion destructive agent powder are mixed in the organic solvent ethylene carbonate to obtain a uniform slurry.

[0030] 2. Apply the paste to the substrate using a doctor blade coating method or a screen printing method, and then dry it to form an SSC layer.

[0031] 3. The pre-fabricated positive electrode layer 110 and negative electrode layer 130 (both containing current collectors) are sandwiched between the SSC layers and laminated. Hot pressing (sintering) is then performed under a set pressure of 35-45 MPa and a temperature of 80-120℃ to finally obtain the all-solid-state battery cell 100. At this time, the sintering temperature and time must be strictly controlled to prevent thermal expansion from causing malfunctions in the induced materials during the manufacturing process.

[0032] Performance verification: such as Figure 2 and Figure 3 As shown, a simulated internal short-circuit heating operation was performed on the battery, causing a local temperature increase. When the temperature reached 180°C, the inducing material began to expand rapidly. Due to the significant difference (more than 5 times) in the thermal expansion coefficients of the inducing material and the SSC, high tensile and shear stresses 150° were generated around the inducing material, inducing multiple through-cracks (such as the first through-crack 160 and the second through-crack 170) within the brittle SSC layer. Measuring the battery's ion resistance after crack formation revealed that it increased to more than 106 times that before operation, confirming that the current path was completely interrupted. Even after cooling the battery to 25°C, the resistance remained interrupted, achieving an irreversible blocking effect.

[0033] Example 2: Selective configuration of the interface layer and stress concentration structure This all-solid-state battery cell uses the same battery structure as in Example 1. The thermal expansion-induced failure material is changed from being dispersed throughout the entire SSC layer to being selectively stacked at the interface between the positive electrode and the SSC layer, forming a thin layer with a thickness of 5 μm. Periodic nanopillar structures 110a (1 μm high, 1 μm spacing) are pre-formed on the surface of the positive electrode layer, protruding towards the SSC layer side. These pillar-like structures function as stress concentration points 190 during expansion.

[0034] Its preparation method is as follows: 1. By combining photolithography and etching processes, a periodic nanopillar structure 110a is formed on the surface of the cathode material.

[0035] 2. On the positive electrode layer with the nanopillar structure, a thermal expansion failure-inducing thin film with a thickness of 5 μm is deposited by sputtering or atomic layer deposition (ALD).

[0036] 3. Subsequently, the pre-formed SSC layer and negative electrode layer are stacked, and the all-solid-state battery cell is obtained by hot pressing. The thermal temperature during thin film deposition must be strictly controlled to prevent false triggering of the induction layer.

[0037] Performance verification: such as Figure 4As shown, when the heating operation reaches the interface temperature, the thin-layered induced material expands. The expansion stress of the thin layer concentrates at the base of the nanopillars in the form of extremely high shear stress. This concentrated stress causes irreversible delamination of the interfacial adhesion and generates cracks within the SSC layer starting from the delamination point. This causes the battery's ion conductivity to drop to zero, completely blocking the current. In this embodiment, although the amount of induced material is significantly reduced, the lower heat generation energy is achieved through the stress concentration structure, ensuring safety while maintaining high energy density.

[0038] Example 3: Application of thermally responsive ionic insulating materials The all-solid-state battery cell adopts the same battery structure as in Example 1. A composite solid electrolyte 200 (a thermally responsive ion-insulating material composed of metal oxides and lithium salts in a mass ratio of 20:80) is embedded in the solid electrolyte layer (SSC layer). This material undergoes an irreversible crystal structure phase transition at a threshold temperature of 180°C, resulting in a sharp decrease in lithium-ion conductivity.

[0039] Its preparation method is as follows: 1. Metal oxides and lithium salts are mixed in a predetermined ratio to synthesize thermally responsive ionic insulating material powder via a solid-state reaction method. By precisely controlling the synthesis conditions, a crystal structure that undergoes an irreversible phase transition at a threshold temperature of 180℃ is obtained.

[0040] 2. Mix the SSC material powder with the above-mentioned thermally responsive ion-insulating material powder, and form an SSC layer using the same process as in Example 1 to prepare an all-solid-state battery cell.

[0041] Performance verification: such as Figure 5 As shown, when abnormal heating causes the temperature to reach 180°C, the material transforms into an ion-insulating phase. Upon cooling, the phase transition is irreversible, and a high-resistivity ion-insulating barrier is permanently formed within the SSC layer. The lithium-ion conduction path is functionally blocked via route 220, and battery function ceases. This confirms that permanent functional blocking can be achieved without physical cracks (damage).

[0042] Example 4: Composite Destruction Structure in Chalcogenide ASSB This all-solid-state battery cell uses the same battery structure as in Example 1. Two types of particles with different coefficients of thermal expansion are mixed within the SSC layer (a 1:1 mass ratio of low-T (150°C) Cu-SiC composite hollow ceramic microspheres and high-T (200°C) SiC-Al composite hollow ceramic microspheres). Simultaneously, a micro-void layer is pre-formed on one side of the SSC layer to aid stress concentration during expansion.

[0043] Its preparation method is as follows: 1. Mix SSC material powder with two types of thermal expansion-induced failure material powders, namely low-T actuating particles and high-T actuating particles, in the optimal ratio to prepare a uniform slurry.

[0044] 2. When applying the paste, a specific printing technique (such as inkjet printing or screen printing) is used to form a pattern, leaving tiny gaps in the SSC layer.

[0045] 3. The battery is then manufactured through lamination and hot pressing. Micro-void layers can also be formed by locally adjusting the SSC sintering conditions.

[0046] Performance Verification: When the internal short circuit induces heat reaching 150°C, the low-T actuating particles expand, generating initial stress. As the temperature rises further to 200°C, the high-T actuating particles generate critical expansion stress, which concentrates in the microporous layer, thereby inducing large-scale through-cracks within the SSC layer. This combination of stress generation and stress concentration structure achieves the dual effect of early cleavage at lower heat energy and more reliable permanent failure.

[0047] Comparative Example 1: Standard all-solid-state battery cell without inducing materials This battery is a standard stacked all-solid-state battery cell, with the SSC layer completely free of thermal expansion-induced materials. Specifically, this all-solid-state battery cell consists of an NCM-based positive electrode layer 110, a lithium metal negative electrode layer 130, and a sulfide-based solid electrolyte layer 120 (SSC layer) (using Li...). 10 GeP2S 12 The stacked all-solid-state battery cell 100 consists of a 50 μm thick layer. The other components and preparation are the same as in Example 1.

[0048] Performance Verification: A simulated internal short circuit was applied to the battery, causing the local temperature to rise. Although the battery resistance temporarily increased, the lack of structural damage prevented the prevention of a thermal runaway-induced cascading reaction, ultimately leading to the entire battery overheating and damage. The experiment confirmed that if the external BMS fails to disconnect the power supply in time, thermal runaway can trigger a domino effect, propagating to adjacent batteries.

[0049] Comparative Example 2: Structure using reversible thermally responsive materials This all-solid-state battery cell uses the same battery structure as in Example 1, but embeds one of two materials within the SSC layer: a reversible phase change material (polyethylene oxide) whose ionic conductivity decreases with increasing temperature and recovers upon cooling, or a reversible thermal expansion material 300 (tungsten zirconate) that shrinks upon cooling. Other components and preparation methods are the same as in Example 1. In this example, tungsten zirconate, a reversible thermal expansion material that shrinks upon cooling, is selected.

[0050] Performance verification: such as Figure 6Heating causes a temporary interruption of ion conductivity. Figure 6 (Above paragraph). However, when the temperature drops to the operating temperature, the thermally responsive material shrinks, the SSC layer recovers from deformation, the battery resistance value basically returns to its pre-operational state, the lithium-ion conduction path is reconstructed (route 320), and the battery enters a rechargeable reset state. Therefore, if the root cause of thermal runaway (such as dendrites) still exists, safety cannot be continuously guaranteed. This fully emphasizes the importance of adopting a "non-restartable design to enhance safety" approach in this invention.

[0051] Comparative Example 3: Material Structure with Linear High Thermal Expansion Coefficient This all-solid-state battery cell uses the same cell structure as in Example 1. A material with a linearly increasing coefficient of thermal expansion (e.g., aluminum, polyethylene) is embedded within the SSC layer, but the material must not exhibit rapid expansion below a specific threshold. In this example, polyethylene is selected. Other components and preparation methods are the same as in Example 1.

[0052] Performance verification: Expansion and stress occurred before the temperature reached 180°C, but the rapid stress increase seen in the early stages of thermal runaway did not occur. The results confirm that extremely high temperatures (e.g., above 350°C) or prolonged periods of constant temperature are required to cause damage, thus failing to achieve the invention's objective of early thermal runaway isolation.

[0053] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A fully solid-state battery cell with a thermal expansion stress-induced irreversible damage mechanism to the solid electrolyte layer, characterized in that, It includes a positive electrode layer, a negative electrode layer, and a solid electrolyte layer stacked between the positive electrode layer and the negative electrode layer. A thermal expansion failure inducing material with a specific threshold temperature is disposed inside the solid electrolyte layer and / or at the electrode contact interface. When the specific threshold temperature is reached, the thermal expansion failure inducing material undergoes a rapid volume expansion, causing the adjacent solid electrolyte layer to fracture.

2. The all-solid-state battery cell with an irreversible damage mechanism of the solid electrolyte layer induced by thermal expansion stress according to claim 1, characterized in that, The average coefficient of thermal expansion of the thermal expansion-induced material is at least three times higher than the average coefficient of thermal expansion of the adjacent solid electrolyte layer.

3. The all-solid-state battery cell with an irreversible damage mechanism of the solid electrolyte layer induced by thermal expansion stress according to claim 2, characterized in that, The average coefficient of thermal expansion of the thermal expansion-induced material is 4-10 times that of the average coefficient of thermal expansion of the adjacent solid electrolyte layer.

4. The all-solid-state battery cell with an irreversible damage mechanism of the solid electrolyte layer induced by thermal expansion stress according to claim 2, characterized in that, The average coefficient of thermal expansion of the thermal expansion-induced failure material is (30-100)×10 -6 / K, the average thermal expansion coefficient of the solid electrolyte layer is (10-30)×10 -6 / K.

5. The all-solid-state battery cell with an irreversible damage mechanism of the solid electrolyte layer induced by thermal expansion stress according to claim 1, characterized in that, The specific threshold temperature range is 150℃ to 300℃.

6. The all-solid-state battery cell with an irreversible damage mechanism of the solid electrolyte layer induced by thermal expansion stress according to claim 1, characterized in that, The thermal expansion failure inducing material is a composite ceramic particle with an average particle size of 1-4 μm.

7. The all-solid-state battery cell with a thermal expansion stress-induced irreversible damage mechanism of the solid electrolyte layer according to claim 6, characterized in that, The composite ceramic particles are one or more of TiC-Ni composite hollow ceramic microspheres, Cu-SiC composite hollow ceramic microspheres, and SiC-Al composite hollow ceramic microspheres.

8. The all-solid-state battery cell with an irreversible damage mechanism of the solid electrolyte layer induced by thermal expansion stress according to claim 1, characterized in that, When the thermal expansion failure inducing material is disposed inside the solid electrolyte layer, the thermal expansion failure inducing material is uniformly dispersed in the solid electrolyte layer at a ratio of (3-10)V / V%; when the thermal expansion failure inducing material is disposed at the electrode contact interface of the solid electrolyte layer, the thickness of the thermal expansion failure inducing material is 0.01-0.1 times the thickness of the solid electrolyte layer.

9. The all-solid-state battery cell with an irreversible damage mechanism of the solid electrolyte layer induced by thermal expansion stress according to claim 1, characterized in that, The thermal expansion failure inducing material is a thermally responsive ionic insulating material, which is a composite solid electrolyte.

10. The all-solid-state battery cell with an irreversible damage mechanism of the solid electrolyte layer induced by thermal expansion stress according to claim 1, characterized in that, The thermal expansion failure-inducing material is surrounded by a stress concentration structure for concentrating thermal expansion stress, wherein the stress concentration structure is a sharpened structural edge or a specific defect layer.

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