All-solid-state battery

Abstract

The present application belongs to the technical field of batteries. Disclosed is an all-solid-state battery. The all-solid-state battery comprises a package, a battery cell assembly, a total positive electrode and a total negative electrode, wherein the package is sealingly wrapped around the outside of the battery cell assembly; the total positive electrode and the total negative electrode are both connected to the peripheral side of the package and are both electrically connected to the battery cell assembly; and the tiled area of the package is A, and the thickness of the package is B, where C=A / B, and 5000 mm≤C≤20000 mm. By means of increasing the tiled area of the package and reducing the thickness of the package of the all-solid-state battery, the uniformity of the entire all-solid-state battery is better.

Description

A type of all-solid-state battery

[0001] This application claims priority to Chinese Patent Application No. 2024218485970, filed with the Chinese Patent Office on July 31, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery technology, and more particularly to an all-solid-state battery. Background Technology

[0003] For all-solid-state batteries, the uniformity of molding and operating pressure has a significant impact on their performance. To provide uniform pressure, current all-solid-state battery structures are generally multi-layered pouch cells. Technical issues

[0004] However, due to limitations in the precision of the manufacturing process, the thickness of each laminated layer often exhibits unevenness on its respective plane, and this unevenness increases dramatically with multiple layers. During manufacturing, uneven pressure distribution often occurs, and even isostatic pressing techniques can cause slight bending or even breakage of the battery. Pressure uniformity and transmission also exist during testing and use; the pressure deep within the battery often differs from the surface pressure, resulting in varying pressures throughout the battery. During operation, areas with higher pressure will gradually degrade in performance until failure. Technical solutions

[0005] This application provides an all-solid-state battery, which includes a package, a cell assembly, a positive electrode, and a negative electrode. The package is sealed around the cell assembly. The positive electrode and the negative electrode are both connected to the periphery of the package and are electrically connected to the cell assembly. The package has a flat area of ​​A and a thickness of B, where C = A / B and 5000mm ≤ C ≤ 20000mm. Beneficial effects

[0006] The beneficial effects of the all-solid-state battery provided in this application are as follows: by increasing the flat area of ​​the encapsulation and reducing the thickness of the encapsulation, the larger the area of ​​the all-solid-state battery on the flat plane, the more significantly the non-uniformity between the layers in the all-solid-state battery is weakened. At the same time, the thickness of the all-solid-state battery is made smaller, and the accumulation of thickness non-uniformity in the thickness direction is smaller, thereby making the uniformity of the entire all-solid-state battery better. This ensures smoother pressure transmission from the inside to the surface of the all-solid-state battery, balances the pressure inside and on the surface of the all-solid-state battery, and avoids the rapid decline in electrical performance at high-pressure locations after a period of use, thus extending the service life of the all-solid-state battery. Attached Figure Description

[0007] Figure 1 is a schematic diagram of the structure of the all-solid-state battery provided in an embodiment of this application;

[0008] Figure 2 is an internal structure diagram of the all-solid-state battery provided in an embodiment of this application;

[0009] Figure 3 is a schematic diagram of the structure of the battery cell provided in an embodiment of this application.

[0010] In the picture:

[0011] 10. Encapsulation; 11. Side sealing area;

[0012] 20. Battery cell assembly; 21. Battery cell; 211. Positive electrode assembly; 2111. Positive electrode sheet; 2112. Positive electrode coating; 212. Electrolyte layer;

[0013] 213. Negative electrode assembly; 2131. Negative electrode sheet; 2132. Negative electrode coating; 2133. Insulating layer;

[0014] 22. Heat dissipation layer; 23. Positive electrode; 24. Negative electrode;

[0015] 30, overall positive electrode; 40, overall negative electrode.

[0016] Implementation methods of this application

[0017] This application provides an all-solid-state battery with better pressure uniformity inside and on the surface. As shown in Figures 1 and 2, the all-solid-state battery includes a package 10, a cell assembly 20, a total positive electrode 30, and a total negative electrode 40. The package 10 is sealed and wrapped around the outside of the cell assembly 20. The total positive electrode 30 and the total negative electrode 40 are both connected to the periphery of the package 10 and are electrically connected to the cell assembly 20. The flat area of ​​the package 10 is A, the thickness of the package 10 is B mm, C=A / B, and 5000mm≤C≤20000mm. The aforementioned all-solid-state battery, by increasing the flat area of ​​the package 10 and reducing its thickness, achieves a larger area of ​​the all-solid-state battery on the flat surface. This makes the non-uniformity between layers in the all-solid-state battery more pronounced. At the same time, the smaller the thickness of the all-solid-state battery, the smaller the cumulative amount of thickness non-uniformity in the thickness direction. This results in better uniformity of the entire all-solid-state battery, ensuring smoother pressure transmission from the inside to the surface. It balances the pressure inside and on the surface of the all-solid-state battery, preventing the electrical performance of areas with higher pressure from declining rapidly after a period of use, thus extending the lifespan of the all-solid-state battery.

[0018] It should be noted that in this embodiment, the all-solid-state battery is mounted on the vehicle chassis, which has a large planar mounting space to provide electric power to the vehicle. In other embodiments, the all-solid-state battery can be installed according to actual usage conditions, and this is not limited here.

[0019] When C < 5000mm, the pressure balance effect is poor. When C > 20000mm, if the thickness of the package 10 is made too thin, it will affect the strength of the entire solid-state battery. Therefore, the range is set to 5000mm ≤ C ≤ 20000mm. For example, C can take values ​​of 5100mm, 5200mm, 5500mm, 5700mm, 6000mm, 6500mm, 7000mm, 7500mm, 8000mm, 8500mm, 9000mm, 9500mm, 10000mm, 11000mm, 12000mm, 13000mm, 14000mm, 15000mm, 16000mm, 17000mm, 18000mm, 19000mm, etc.

[0020] In some embodiments of this application, 750,000 mm² ≤ A ≤ 2,000,000 mm², and 100 mm ≤ B ≤ 150 mm. This makes the area of ​​the all-solid-state battery suitable for most application scenarios, and the thickness of the solid-state battery does not occupy excessive space in the height direction. For example, A can take values ​​of 760,000 mm², 770,000 mm², 780,000 mm², 790,000 mm², 800,000 mm², 900,000 mm², 120,000 mm², 1400,000 mm², 1600,000 mm², 1800,000 mm², etc., and B can take values ​​of 1110 mm, 120 mm, 130 mm, 140 mm, etc. Optionally, 100 mm ≤ B ≤ 125 mm, appropriately reducing the thickness of the package 10 can effectively increase the uniformity of pressure transmission and keep the pressure in the thickness direction of the cell assembly 20 tending to be consistent.

[0021] In some embodiments of this application, as shown in Figure 1, the length of package 10 is defined as D, the width of package 10 is defined as E, F = D / E, and 1.5 ≤ F ≤ 4. This aspect ratio results in a more uniform torque distribution for the all-solid-state battery under stress, preventing damage to certain areas due to excessive torque. For example, E can take values ​​such as 2.2, 2.5, 2.8, 3, 3.2, 3.4, etc. Optionally, 2.5 ≤ F ≤ 3.5 further ensures the uniformity of torque distribution for the all-solid-state battery under stress.

[0022] In some embodiments of this application, 1500mm≤D≤2000mm, 500mm≤E≤1000mm. This size can adapt well to most usage scenarios. For example, D can take values ​​of 1600mm, 1700mm, 1800mm, 1900mm, etc., and E can take values ​​of 600mm, 700mm, 800mm, 900mm, etc.

[0023] In some embodiments of this application, as shown in FIG2, the battery cell assembly 20 includes N battery cells 21 stacked together, where 5 ≤ N ≤ 20. Exemplarily, N can take values ​​of 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, and 19. By appropriately reducing the number of battery cells 21, the thickness of the package 10 can be reduced accordingly. As the number of stacked layers increases, the uniform force transmission effect inside the battery cell assembly 20 decreases, and the force distribution in the middle area becomes uneven. Below 20 layers, the uniform force transmission can be maintained. Optionally, 5 ≤ N ≤ 10 ensures optimal force transmission.

[0024] In some embodiments of this application, as shown in FIG2, the all-solid-state battery further includes a total positive electrode 30 and a total negative electrode 40 both extending from the periphery of the package. N cells 21 are connected in series, with the positive electrode 23 of one cell 21 connected to the total positive electrode 30 and the negative electrode 24 of one cell 21 connected to the total negative electrode 40. By connecting N cells 21 in series, the resulting all-solid-state battery can have a voltage that meets the usage requirements, increasing the energy density of the all-solid-state battery, optimizing the battery, and meeting the device usage requirements. In addition, compared with the assembly structure of multiple cells 21 connected in parallel to form the same capacity in related technologies, the use of battery wires in this embodiment makes the structure of the battery with the same capacity more streamlined and reduces costs.

[0025] In some embodiments of this application, as shown in FIG3, the battery cell 21 includes a positive electrode component 211, a negative electrode component 213, and an electrolyte layer 212. Negative electrode components 213 are disposed on both sides of the positive electrode component 211, and an electrolyte layer 212 is disposed between the positive electrode component 211 and the corresponding negative electrode component 213. With this arrangement, compared to a scheme where the positive electrode component 211 and negative electrode component 213 are arranged in a one-to-one correspondence in the battery cell 21, the exchange rate of active materials between the positive electrode component 211 and the negative electrode component 213 is higher, a single battery cell 21 can provide more power, and the arrangement of a set of positive electrode components 211 can be eliminated.

[0026] In some embodiments of this application, the positive electrode assembly 211 includes a positive electrode sheet 2111 and a positive electrode coating 2112. Both sides of the positive electrode sheet 2111 are coated with the positive electrode coating 2112, and an electrolyte layer 212 is stacked on the side of each positive electrode coating 2112 facing away from the positive electrode sheet 2111. It should be noted that the positive electrode sheet 2111 is also called the positive electrode 23 current collector. In Figure 2, the positive electrode 23 of a single cell 21 can be formed by extending the positive electrode sheet 2111, or it can be formed by welding it to the outside of the positive electrode sheet 2111. This method allows for the selection of a suitable thickness for the positive electrode 23 in the cell 21, ensuring sufficient strength of the positive electrode 23. The active material of the positive electrode 23 mainly exists in the positive electrode coating 2112, where it undergoes ion exchange with the negative electrode assembly 213.

[0027] In some embodiments of this application, as shown in FIG3, the negative electrode assembly 213 includes a negative electrode coating 2132, a negative electrode sheet 2131, and an insulating layer 2133. The negative electrode coating 2132, the negative electrode coating 2132, and the insulating layer 2133 are sequentially stacked on the side of the electrolyte layer 212 facing away from the positive electrode coating 2112. Through the above arrangement, the insulating layer 2133 can insulate against the negative electrode sheet 2131 of the adjacent cell 21. At the same time, the insulating layer 2133 can also provide better support, improving the structural strength of the surface of each cell 21 under the premise of multi-layer stacking, and improving the compressive and bending resistance. Among them, the active material of the negative electrode 24 is mainly present in the negative electrode coating 2132 to exchange ions with the positive electrode assembly 211. It should be noted that the negative electrode 2131 is also called the negative electrode 24 current collector. The negative electrode 24 of a single cell 21 can be formed by extending the negative electrode 2131 (two negative electrode 2131 are extended and welded together), or it can be formed by welding it to the outside of the negative electrode 2131. This solution allows the cell 21 to select a negative electrode 24 of appropriate thickness to ensure that the strength of the negative electrode 24 is sufficient.

[0028] For all-solid-state batteries, their internal resistance is higher than that of liquid batteries, resulting in a severe temperature rise during fast charging and discharging, which is detrimental to stable battery operation. Typically, a suitable heat dissipation layer 22 and a heat insulation layer are placed within the battery to control temperature. However, these layers are far from the interior of the cell assembly 20, resulting in poor thermal conductivity and failing to meet the requirements.

[0029] As shown in Figure 2, a heat dissipation layer 22 is disposed between at least any two adjacent battery cells 21. By distributing the heat dissipation layer 22 inside the battery cell assembly 20, heat can be transferred more quickly from the inside of the battery cell assembly 20 to the surface, thereby maintaining the temperature uniformity of the battery cell assembly 20. Compared with traditional stacked or wound batteries, the heat dissipation effect is better. Moreover, the solid electrolyte does not have fluidity, avoiding the risk of corrosion of the heat dissipation layer 22.

[0030] In some embodiments of this application, the heat dissipation layer 22 is a graphene aerogel layer, which can play a role in uniformizing stress, making the transmission of internal forces of the battery cell assembly 20 more controllable and consistent, and helping to improve the cycle stability of the battery cell assembly 20.

[0031] In some embodiments of this application, as shown in Figure 2, the thickness of the heat dissipation layer 22 is G, where 0.5mm ≤ G ≤ 5mm. Here, when G > 5mm, the increase in the overall thickness of the cell assembly 20 is significant, which is not conducive to reducing the thickness of the cell assembly 20. When G < 0.5mm, the heat dissipation and stress uniformity effects are poor. Therefore, the range of G is set to 0.5mm ≤ G ≤ 5mm. For example, the value of G can be selected as 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, etc. Optionally, 1mm ≤ G ≤ 3mm, or G = 1.2mm. If the heat dissipation layer 22 is too thin, it cannot withstand the volume expansion changes of the cell assembly 20 during operation, making it difficult to uniformly transmit force. If the heat dissipation layer 22 is too thick, it will cause severe deformation of the aerogel during battery pressurization, affecting the internal structure of the battery.

[0032] In some embodiments of this application, as shown in FIG1, the package 10 is sealed around its perimeter to form four flat side sealing areas 11, with the aforementioned total positive electrode 30 and the aforementioned total negative electrode 40 extending from the two opposing side sealing areas 11, respectively. This arrangement allows the package 10 to seal the exterior of the battery cell assembly 20, preventing moisture or other contaminants from entering and affecting the performance of the battery cell assembly 20, or from reacting with the material of the battery cell 21 to produce toxic gases.

[0033] In some embodiments of this application, the outer surface of the package 10 is wrapped with an aluminum-plastic film, which can better seal the battery and prevent the ingress of external gases or liquids. Furthermore, since the battery cell assembly wrapped inside the aluminum-plastic film is solid-state, it is less prone to shifting compared to a pouch battery. In other words, the battery cell assembly and the aluminum-plastic film can support the entire shape of the all-solid-state battery, reducing wear on the aluminum-plastic film surface and ensuring that the battery's range does not decrease due to wear on the aluminum-plastic film.

[0034] In some embodiments of this application, the shape of the battery cell assembly can be cylindrical, cubic, or polygonal, that is, the battery cell assembly is formed by stacking layers rather than by winding.

[0035] In some embodiments of this application, the all-solid-state battery provided in this embodiment can be applied to vehicles. Specifically, the vehicle may include commercial vehicles, special vehicles, electric bicycles, electric motorcycles, electric scooters, and other electric vehicles that require the use of all-solid-state batteries to provide them with power to drive them.

[0036] [Amended according to Rule 26, 18.11.2024] For example, the measurement data of all-solid-state batteries of different specifications are shown in Table 1.

[0037] [Revised according to Detailed Rules 26, November 18, 2024] Table 1

[0038] In the table, the higher the percentage of the pressure uniformity area, the better the pressure uniformity of the solid-state battery surface.

[0039] In the first set of data, Example 1 has a flat area of ​​1,500,000 mm², a thickness of 100 mm, a C value of 20,000, a package length of 1,500 mm, a package width of 1,000 mm, an F value of 1.5, 5 cells, and a heat dissipation layer thickness of 0.5 mm. All of these parameters are within the range given in this embodiment. The single-cell battery capacity is 101.8 Ah, the single-cell battery charge is 351.2 Wh, the single-cell battery mass is 1.028 kg, the battery energy density is 341.6 Wh / kg, and the pressure uniformity area ratio is 91.28%. In Comparison 1, the thickness is 160 mm, which is outside the range given in this embodiment. The battery energy density is 324.6 Wh / kg, and other parameters are the same as in Example 1. The pressure uniformity area ratio is 90.12%, which is 1.16% higher than that in Comparison 1.

[0040] In the second set of data, Example 1 has a flat area of ​​1,661,750 mm², a thickness of 110 mm, a C-value of 15,000, a package length of 1,955 mm, a package width of 850 mm, an F-value of 2.3, 7 cells, and a heat dissipation layer thickness of 1 mm. All of these parameters are within the range given in this embodiment. The single-cell battery capacity is 112.9 Ah, the single-cell battery charge is 389.5 Wh, the single-cell battery mass is 1.126 kg, the battery energy density is 345.9 Wh / kg, and the pressure uniformity area ratio is 90.33%. In Comparison 2, the thickness is 170 mm, which is outside the range given in this embodiment. The battery energy density is 318.2 Wh / kg, and other parameters are the same as in Example 2. The pressure uniformity area ratio is 88.43%, which is 1.9% higher than that of Comparison 2.

[0041] In the third set of data, Example 3 has a flat area of ​​1,267,500 mm², a thickness of 120 mm, a C value of 10,000, a package length of 1,950 mm, a package width of 650 mm, an F value of 3, 10 cells, and a heat dissipation layer thickness of 2 mm. All of these parameters are within the range given in this embodiment. The single-cell battery capacity is 86.2 Ah, the single-cell battery charge is 297.4 Wh, the single-cell battery mass is 0.863 kg, the battery energy density is 344.6 Wh / kg, and the pressure uniformity area ratio is 97.43%. In Comparison 3, the thickness is 180 mm, which is outside the range given in this embodiment. The battery energy density is 292.9 Wh / kg, and other parameters are the same as in Example 3. The pressure uniformity area ratio is 94.23%, which is 3.2% higher than that of Comparison 3.

[0042] In the fourth set of data, Example 4, the flat area is 1028500mm², the thickness is 130mm, the C-value is 8000, the package length is 1870mm, the package width is 550mm, the F-value is 3.4, the number of cells is 13, and the heat dissipation layer thickness is 3mm. All of the above parameters are within the range given in this embodiment. The single cell capacity is 69.7Ah, the single cell energy is 240.5Wh, the single cell mass is 0.704Kg, the battery energy density is 341.6Wh / Kg, and the pressure uniformity area ratio is 95.89%. In Comparison 1, the thickness is 160mm, which is not within the range given in this embodiment. The battery energy density is 300.6Wh / Kg, and other parameters are the same as in Example 4. The pressure uniformity area ratio is 93.77%. The pressure uniformity area ratio in Example 4 is 2.12% higher than that in Comparison 4.

[0043] In the fifth set of data, Example 1 has a flat area of ​​1,500,000 mm², a thickness of 100 mm, a C value of 20,000, a package length of 1,500 mm, a package width of 1,000 mm, an F value of 1.5, 5 cells, and a heat dissipation layer thickness of 0.5 mm. All of these parameters are within the range given in this embodiment. The single-cell battery capacity is 101.8 Ah, the single-cell battery charge is 351.2 Wh, the single-cell battery mass is 1.028 kg, the battery energy density is 341.6 Wh / kg, and the pressure uniformity area ratio is 91.28%. In Comparison 1, the thickness is 160 mm, which is outside the range given in this embodiment. The battery energy density is 324.4 Wh / kg, and other parameters are the same as in Example 1. The pressure uniformity area ratio is 87.65%. The pressure uniformity area ratio in Example 5 is 2.46% higher than that in Comparison 5.

[0044] In summary, by changing the thickness parameter to a value outside the range of parameters in this embodiment, it can be seen from the above data that in each set of examples and comparisons, the all-solid-state battery in this embodiment has a higher proportion of uniform pressure area in the example data. In particular, the thickness parameter has a significant impact on the proportion of uniform pressure area. When the thickness is set to a value outside the given range, the proportion of uniform pressure area decreases. Therefore, solid-state batteries that conform to the data range of this embodiment perform better in terms of balancing pressure, avoiding the situation where battery performance deteriorates after long-term use due to uneven pressure.

Claims

1. A full solid-state battery, comprising a package (10), an electric core assembly (20), a total positive electrode (30) and a total negative electrode (40), the package (10) is externally sealedly wrapped to the electric core assembly (20), the total positive electrode (30) and the total negative electrode (40) are both connected to the peripheral side of the package (10) and are both electrically connected with the electric core assembly (20); The area of the package (10) is A, the thickness of the package (10) is B, C=A / B, 5000mm≤C≤20000mm.

2. The all-solid battery according to claim 1, wherein 750000mm2≤A≤2000000mm2, 100mm≤B≤150mm.

3. The all-solid battery according to claim 1, wherein Define the length of the package (10) as D, define the width of the package (10) as E, F=D / E, 1.5≤F≤4.

4. The all-solid battery according to claim 3, wherein 1500mm≤D≤2000mm, 500mm≤E≤1000mm.

5. The all-solid battery according to any one of claims 1 to 4, wherein The electric core assembly (20) comprises N electric cores (21) arranged in a stack, wherein: 5≤N≤20; and / or At least a heat dissipation layer (22) is arranged between any two adjacent electric cores (21).

6. The all-solid battery according to claim 5, wherein The thickness of the heat dissipation layer (22) is G, 0.5mm≤G≤5mm.

7. The all-solid battery according to claim 5, wherein The full solid-state battery further comprises the total positive electrode (30) and the total negative electrode (40) both extending from the peripheral side of the package (10), and N electric cores (21) arranged in series, wherein the positive electrode (23) of one of the electric cores (21) is connected with the total positive electrode (30), and the negative electrode (24) of one of the electric cores (21) is connected with the total negative electrode (40).

8. The all-solid battery according to claim 5, wherein The electric core (21) comprises: a positive electrode assembly (211); a negative electrode assembly (213) and an electrolyte layer (212), both sides of the positive electrode assembly (211) are provided with the negative electrode assembly (213), and the positive electrode assembly (211) and the negative electrode assembly (213) on the corresponding side are provided with the electrolyte layer (212).

9. The all-solid battery according to claim 8, wherein The positive electrode assembly (211) comprises a positive electrode sheet (2111) and a positive electrode coating (2112), both sides of the positive electrode sheet (2111) are coated with the positive electrode coating (2112), and each positive electrode coating (2112) is stacked with the electrolyte layer (212) on the corresponding side away from the positive electrode sheet (2111); and / or The negative electrode assembly (213) comprises a negative electrode coating (2132), a negative electrode sheet (2131) and an insulating layer (2133), the negative electrode coating (2132), the negative electrode coating (2132) and the insulating layer (2133) are sequentially stacked on the side of the electrolyte layer (212) away from the positive electrode coating (2112).

10. The all-solid battery according to any one of claims 1 to 4, wherein The four peripheries of the package (10) are sealed to form four flat side sealing areas (11), and the total positive electrode (30) and the total negative electrode (40) are respectively extended from the opposite two side sealing areas (11).

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