Semi-solid battery
By introducing oxide particles into the electrolyte layer to adsorb the electrolyte solution and constructing a multi-particle structure, the problems of increased ion migration resistance and insufficient electrolyte solution in the solid electrolyte layer are solved, thus achieving efficient ion migration and stable battery performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-06
- Publication Date
- 2026-03-13
AI Technical Summary
In a solid electrolyte layer, the resistance to ion migration increases, and both too much and too little electrolyte solution will lead to a decrease in battery performance, especially at low or high temperatures.
Oxide particles that come into contact with solid electrolyte particles are introduced into the electrolyte layer to adsorb the electrolyte solution, forming a structure of multiple solid electrolyte particles, oxide particles and voids. This ensures that ions migrate through shorter paths, and the electrolyte solution is uniformly dispersed by controlling the coating density and distribution of oxide particles.
Even with a small amount of electrolyte solution, high ion migration efficiency ensures stable battery performance, suppressing increases in resistance and decreases in charge/discharge capacity, and maintaining high-efficiency operation, especially under temperature variations.
Smart Images
Figure CN121662921A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to a semi-solid battery. Background Technology
[0002] Traditional all-solid-state secondary batteries include a positive electrode (including a positive electrode current collector and a positive electrode active material layer), a negative electrode (including a negative electrode current collector and a negative electrode active material layer), and a solid electrolyte layer disposed between the positive electrode and the negative electrode (e.g., Japanese Unexamined Patent Application Publication No. 2021-141064). Summary of the Invention
[0003] The problem to be solved by the present invention In a solid electrolyte layer, ions migrate through the contact area between two solid electrolytes. If the contact area of each solid electrolyte is small, the resistance to ion migration increases. Therefore, one approach is to add an electrolyte solution to the solid electrolyte layer to allow ions to migrate through areas outside the contact area. However, with this method, problems are likely to arise as the amount of electrolyte solution increases, such as increased viscosity at low temperatures leading to increased resistance, and electrolyte decomposition at high temperatures. On the other hand, if the amount of electrolyte solution is small, unwetted solid electrolytes may cause increased resistance to ion migration, and the electrolyte solution may solidify.
[0004] This disclosure addresses this point, with the aim of promoting ion migration in the electrolyte layer with a small amount of electrolyte solution.
[0005] Problem-solving methods The semi-solid battery according to this disclosure includes: a positive electrode layer including a positive electrode current collector and a positive electrode active material; a negative electrode layer including a negative electrode current collector and a negative electrode active material; and an electrolyte layer disposed between the positive electrode layer and the negative electrode layer, and having an electrolyte solution that flows between adjacent solid electrolyte particles, wherein the electrolyte layer includes oxide particles that contact the solid electrolyte particles and adsorb the electrolyte solution.
[0006] The electrolyte layer may include multiple solid electrolyte particles, multiple oxide particles, a void portion surrounded by multiple solid electrolyte particles, and an electrolyte solution located in a portion of the void portion.
[0007] The electrolyte layer may include oxide particles coated on the surface of solid electrolyte particles and having a particle size smaller than that of the solid electrolyte particles.
[0008] The electrolyte layer may include a predetermined number or fewer oxide particles coated on the surface of solid electrolyte particles at predetermined intervals.
[0009] The surface of solid electrolyte particles may include areas coated with oxide particles and areas not coated with oxide particles.
[0010] The oxide particles may contain zirconium oxide or tungsten dioxide.
[0011] The positive electrode layer may include oxide particles coated on the surface of the positive electrode active material, and the negative electrode layer may include oxide particles coated on the surface of the negative electrode active material.
[0012] The volume of the oxide particles coated on the solid electrolyte particles can be less than a predetermined proportion of the volume of the solid electrolyte particles.
[0013] The solid electrolyte particles coated with oxide particles may be further included in at least one of the positive electrode layer or the negative electrode layer.
[0014] Effects of the present invention According to the present invention, it is possible to achieve the effect of promoting ion migration in the electrolyte layer with a small amount of electrolyte solution. Attached Figure Description
[0015] Figure 1 An overview of the semi-solid battery 1 according to this embodiment is shown.
[0016] Figure 2 The pathways of ion migration in electrolyte solution 32 are shown.
[0017] Figure 3 The graph shows the relationship between the resistance value of the battery cell and the amount of electrolyte solution.
[0018] Figure 4 The relationship between the input and output of the semi-solid cell 1 and temperature is shown.
[0019] Figure 5 Solid electrolyte particles 31 coated with oxide particles 33 are shown.
[0020] [Explanation of reference numerals in the attached image] 1: Semi-solid battery 10: Positive electrode layer 11: Positive electrode current collector 12: Positive electrode active material 20: Negative electrode layer 21: Negative electrode current collector 22: Negative electrode active material 30: Electrolyte layer 31: Solid electrolyte particles 31a: Solid electrolyte particles 31b: Solid electrolyte particles 31c: Solid electrolyte particles 32: Electrolyte solution 33: Oxide particles 33a: Oxide particles 33b: Oxide particles 34: Gap portion Detailed Implementation
[0021] <Overview of Semi-Solid Cell 1> Figure 1 An overview of the semi-solid battery 1 according to this embodiment is shown. Figure 1 The semi-solid battery 1 shown includes a positive electrode layer 10, a negative electrode layer 20, and an electrolyte layer 30, and has a structure in which the negative electrode layer 20, the electrolyte layer 30, and the positive electrode layer 10 are stacked in this order. The semi-solid battery 1 is a secondary battery, such as a lithium-ion battery.
[0022] The positive electrode layer 10 is a layer through which ions (e.g., lithium ions in a lithium-ion battery) migrate during the discharge of the semi-solid battery 1, and includes a positive electrode current collector 11 and a positive electrode active material 12. The positive electrode current collector 11 is a conductor that collects current, for example, made of aluminum. The positive electrode active material 12 is a material that receives ions during discharge, for example, lithium cobalt oxide.
[0023] The negative electrode layer 20 is a layer through which ions migrate during the charging of the semi-solid battery 1, and includes a negative electrode current collector 21 and a negative electrode active material 22. The negative electrode current collector 21 is a conductor that collects current, for example, made of copper. The negative electrode active material 22 is a material that receives ions during charging, for example, graphite.
[0024] An electrolyte layer 30 is disposed between the positive electrode layer 10 and the negative electrode layer 20, and includes a plurality of solid electrolyte particles 31. The solid electrolyte particles 31 are a material used to allow ions to migrate to the positive electrode active material 12 during discharge of the semi-solid battery 1, and to allow ions to migrate to the negative electrode active material 22 during charging of the semi-solid battery 1. For example, the solid electrolyte particles 31 are oxide-based solid electrolytes, such as perovskite-type La... 0.51 Li 0.34 TiO 2.94 However, it can also be a sulfide-based solid electrolyte, a halide-based solid electrolyte, or a hydride-based solid electrolyte.
[0025] In the electrolyte layer 30, a fluid electrolyte solution 32 exists between adjacent solid electrolyte particles 31. For example, the electrolyte solution 32 is a mixed solvent of cyclic carbonates and chain carbonates, specifically a mixed solvent of ethylene carbonate and dimethyl carbonate.
[0026] Because of the presence of electrolyte solution 32 as described above, ions can migrate along the shorter of the following paths: a) through the contact surface between solid electrolyte particle 31 and another solid electrolyte particle 31; b) through the electrolyte solution 32 in contact with both solid electrolyte particle 31 and another solid electrolyte particle. Specifically, when electrolyte solution 32 is absent, ions migrate along... Figure 1 The ions migrate along path R1, but when electrolyte solution 32 is present, the ions migrate along path R2, which is shorter than path R1. Therefore, compared to the case where electrolyte solution 32 is absent, the time required for ion migration in the semi-solid cell 1 can be shortened, thereby improving the output.
[0027] However, when the temperature of the electrolyte solution 32 decreases (e.g., 5°C or lower), its viscosity increases, thereby increasing internal resistance and decreasing voltage, thus reducing charge / discharge capacity. On the other hand, if the temperature rises to a higher level (e.g., 40°C or higher), the electrolyte solution 32 may react with the positive electrode active material 12 or the negative electrode active material 22, or undergo self-decomposition, which also leads to a decrease in charge / discharge capacity. If the amount of electrolyte solution 32 in the electrolyte layer 30 is reduced to suppress this decrease in charge / discharge capacity caused by temperature changes, problems may arise in the migration of ions at the solid electrolyte particles 31 that are not wetted by the electrolyte solution 32, and the electrolyte solution 32 may also solidify.
[0028] Conversely, the electrolyte layer 30 includes oxide particles 33 that contact the solid electrolyte particles 31 and adsorb the electrolyte solution 32. The oxide particles 33 are oxides of metallic elements, larger than elements such as nickel or aluminum, for example, zirconium oxide or tungsten dioxide. With this configuration, in the electrolyte layer 30, the oxide particles 33 adsorbing the electrolyte solution 32 can be dispersedly contacted with the solid electrolyte particles 31. Therefore, even if the amount of electrolyte solution 32 is small, each solid electrolyte particle 31 can contact the electrolyte solution 32. Thus, in the electrolyte layer 30, even if the amount of electrolyte solution 32 is small, ions can easily migrate through the electrolyte solution 32.
[0029] Furthermore, the melting point of the electrolyte solution 32 can be lowered and the ionic conductivity can be increased near the oxide particles 33 due to their presence. Therefore, the decrease in charge / discharge capacity can be suppressed in the electrolyte layer 30. Moreover, by using oxides of metal elements with relatively large sizes, such as zirconium oxide or tungsten oxide, as oxide particles 33 in the electrolyte layer 30, the surface area of the oxide particles 33 can be increased. Therefore, the oxide particles 33: i) can more effectively suppress the decrease in charge / discharge capacity, and ii) can also suppress changes in the crystal structure of the solid electrolyte particles 31 caused by the diffusion of metal elements due to the reaction between the oxide particles 33 and the solid electrolyte particles 31, which would make ion migration more difficult.
[0030] The structure of electrolyte layer 30 will be described in detail below.
[0031] <Structure of Electrolyte Layer 30> like Figure 1 As shown, the electrolyte layer 30 includes a plurality of solid electrolyte particles 31, a plurality of oxide particles 33, a void portion 34 surrounded by the plurality of solid electrolyte particles 31, and an electrolyte solution 32 located in a portion of the void portion 34. For example, when the void portion 34 occupies 20% of the volume of the electrolyte layer 30, the volume of the portion is 25% of the void portion 34 (i.e., 5% of the volume of the electrolyte layer 30).
[0032] Since the oxide particles 33 containing zirconium oxide or tungsten dioxide do not allow ions to pass through the interior of the oxide particles 33, the ions will migrate through the electrolyte solution 32 adsorbed on the oxide particles 33. Figure 2 The pathway of ion migration through electrolyte solution 32 is shown. Figure 2 Multiple solid electrolyte particles 31 (solid electrolyte particles 31a, 31b, and 31c), an electrolyte solution 32, and oxide particles 33 are shown. Figure 2 In the process, ions migrate from solid electrolyte particle 31a to solid electrolyte particle 31c. In the absence of electrolyte solution 32 and oxide particles 33, ions migrate along path R3. However, when electrolyte solution 32 and oxide particles 33 are present, ions migrate along path R4, which is shorter than path R3 and passes through electrolyte solution 32.
[0033] With the above structure, ions can migrate through the electrolyte solution 32 in the electrolyte layer 30. The electrolyte solution is adsorbed onto the oxide particles 33 that are in contact with (or close to) the solid electrolyte particles 31, thus shortening the ion migration distance. Therefore, even with a small amount of electrolyte solution 32, the semi-solid battery 1 can promote ion migration (i.e., reduce the resistance of the battery cell). Figure 3It is a graph showing the relationship between the resistance value of a battery cell and the amount of electrolyte solution. Figure 3 The horizontal axis in the diagram represents the volume of the electrolyte solution. Figure 3 The vertical axis in the graph represents the resistance value of the battery cell. For example... Figure 3 As shown, when the amount of electrolyte solution is L, the resistance value of the battery cell of the semi-solid battery 1 excluding oxide particles 33 is V1, while the resistance value of the battery cell of the semi-solid battery 1 including oxide particles 33 is V2, which is lower than V1.
[0034] Furthermore, near the oxide particles 33, the melting point of the electrolyte solution 32 decreases and the ionic conductivity increases, thus the semi-solid battery 1 can suppress the decrease in charge / discharge capacity even at low temperatures.
[0035] Figure 4 The relationship between the input and output of the semi-solid cell 1 and temperature is shown. Figure 4 The horizontal axis represents the temperature in semi-solid cell 1. Figure 4 The vertical axis represents the input and output of the semi-solid-state battery 1. For example, input refers to the amount of charge per unit time, and output refers to the amount of discharge per unit time. Figure 4 As shown, the input and output of the semi-solid battery 1 including oxide particles 33 do not decrease at low temperatures (solid line), which is different from the input and output of the semi-solid battery 1 without oxide particles 33 (dashed line). Specifically, at temperature T2, the difference between the solid line and the dashed line is D2, but at temperature T1 (lower than temperature T2), the difference between the solid line and the dashed line is D1, which is greater than D2.
[0036] In the electrolyte layer 30, the more uniformly the oxide particles 33 adsorbed with electrolyte solution 32 are dispersed, the less electrolyte solution 32 is required. In the electrolyte layer 30, by using relatively large metal elements as oxide particles 33, the oxide particles 33 are easily and uniformly dispersed. However, even when oxide particles 33 are included in the electrolyte layer 30, they are not necessarily uniformly dispersed. Furthermore, since oxide particles 33 are inactive, increasing their amount increases the proportion of inactive material in the electrolyte layer 30, leading to a decrease in energy density.
[0037] Therefore, the electrolyte layer 30 may include oxide particles 33 coated on the surface of the solid electrolyte particles 31, the particle size of which is smaller than the size of the solid electrolyte particles 31. The surface of the solid electrolyte particles 31 coated with oxide particles 33 may include areas coated with oxide particles 33 and areas not coated with oxide particles 33. That is, the semi-solid battery 1 can be assembled by adding multiple solid electrolyte particles 31 to the electrolyte layer 30, with a portion of the surface of these solid electrolyte particles pre-coated with oxide particles 33.
[0038] The above-described structure increases the probability of uniform dispersion of oxide particles 33 within the electrolyte layer 30. Therefore, the electrolyte layer 30 can include an appropriate amount of oxide particles 33 to achieve uniform dispersion, thereby suppressing a decrease in energy density. Furthermore, by uniformly dispersing the oxide particles 33, the electrolyte solution 32 can also be uniformly dispersed, making it more likely for the electrolyte solution 32 to approach each solid electrolyte particle 31, thus reducing the amount of electrolyte solution 32. Therefore, even in a small amount of electrolyte solution 32, ions can easily migrate within the electrolyte layer 30.
[0039] Figure 5 Solid electrolyte particles 31 coated with oxide particles 33 are shown. Figure 5 Solid electrolyte particles 31, electrolyte solution 32, and multiple oxide particles 33 are shown. For ease of explanation, Figure 5 A plurality of oxide particles 33 are shown coated on the outer periphery of a cross section of a solid electrolyte particle 31 obtained by cutting along a single plane, wherein oxide particles 33a and oxide particles 33b are indicated by reference numerals.
[0040] like Figure 5 As shown, the electrolyte layer 30 includes a predetermined number or fewer oxide particles 33 coated on the surface of the solid electrolyte particles 31 at predetermined intervals W. The predetermined number, for example, is 16, and can be on the outer periphery of a cross-section of the solid electrolyte particles 31 obtained by cutting along a single plane, or on the entire surface of the solid electrolyte particles 31. The predetermined interval W is a value obtained by dividing the length of the outer periphery of the solid electrolyte particles 31 by the number of oxide particles 33 disposed on one outer periphery of the solid electrolyte particles 31. This configuration disperses regions in the solid electrolyte particles 31 where ions cannot migrate (i.e., regions coated with oxide particles 33), thereby promoting ion migration.
[0041] The volume of oxide particles 33 coated on the solid electrolyte particles 31 can be less than a predetermined proportion of the volume of the solid electrolyte particles 31. For example, the predetermined proportion is a fixed value of 1% or more, or 2% or less. Specifically, when the radius of the solid electrolyte particles 31 is 10 μm and the radius of the oxide particles 33 is 1 μm, the volume of the oxide particles 33 is 0.1% of the volume of the solid electrolyte particles 31. Therefore, when the predetermined proportion is 2%, fewer than 20 oxide particles 33 are coated on each solid electrolyte particle 31. With this structure, an unnecessary increase in the volume of the oxide particles 33 can be suppressed, and therefore, the semi-solid battery 1 can suppress the decrease in energy density.
[0042] <First Amendment Example> In the foregoing description, an example was given of a structure in which solid electrolyte particles 31 in the electrolyte layer 30 are coated with oxide particles 33, but this disclosure is not limited thereto. In the semi-solid battery 1, the positive electrode layer 10 may include oxide particles 33 coated on the surface of the positive electrode active material 12, and the negative electrode layer 20 may include oxide particles 33 coated on the surface of the negative electrode active material 22. In the positive electrode layer 10, the electrolyte solution 32 may be present between adjacent positive electrode active materials 12, while in the negative electrode layer 20, the electrolyte solution 32 may be present between adjacent negative electrode active materials 22.
[0043] In this configuration, ions can migrate through the electrolyte solution 32 adsorbed on the oxide particles 33 in the positive electrode layer 10 and the negative electrode layer 20. Therefore, in the semi-solid battery 1, ion migration can be promoted more effectively than when the oxide particles 33 are coated only on the solid electrolyte particles 31, thereby improving the output.
[0044] <Second Amendment> In the foregoing description, an example of a structure in which solid electrolyte particles 31 are included in electrolyte layer 30 has been provided, but this disclosure is not limited thereto. Solid electrolyte particles 31 may be further included in at least one of positive electrode layer 10 or negative electrode layer 20. The surface of solid electrolyte particles 31 may be coated with oxide particles 33.
[0045] <Effects of Semi-Solid Battery 1> As described above, the semi-solid battery 1 includes: a positive electrode layer 10, including a positive electrode current collector 11 and a positive electrode active material 12; a negative electrode layer 20, including a negative electrode current collector 21 and a negative electrode active material 22; and an electrolyte layer 30 disposed between the positive electrode layer 10 and the negative electrode layer 20, and having an electrolyte solution 32 that is fluid between adjacent solid electrolyte particles 31, the electrolyte layer 30 including oxide particles 33 that are in contact with the solid electrolyte particles 31 and adsorb the electrolyte solution 32.
[0046] In the semi-solid battery 1 constructed as described above, the oxide particles 33 adsorbed with the electrolyte solution 32 are dispersed in the electrolyte layer 30 in a state of contact with each solid electrolyte particle 31. Therefore, even if the amount of electrolyte solution 32 is small, ion migration can be easily facilitated. Furthermore, as... Figure 5 As shown, by coating the surface of the solid electrolyte particles 31 with oxide particles 33 at predetermined intervals, the oxide particles 33 can be uniformly dispersed. Therefore, in the semi-solid battery 1, the electrolyte solution 32 wetting the oxide particles 33 can be uniformly dispersed, thereby easily reducing the amount of electrolyte solution 32.
[0047] This disclosure has been described based on exemplary embodiments. The technical scope of this disclosure is not limited to the scope explained by the above embodiments, and various changes and modifications can be made within the scope of this disclosure. For example, all or part of the apparatus can be configured with any functionally or physically distributed or integrated units. Furthermore, new exemplary embodiments resulting from any combination of these are also included in the exemplary embodiments of this disclosure. Moreover, the effects of the new exemplary embodiments resulting from the combination also have the effects of the original exemplary embodiments.
Claims
1. A semi-solid battery, comprising: The positive electrode layer includes a positive electrode current collector and a positive electrode active material; The negative electrode layer includes a negative electrode current collector and a negative electrode active material; as well as An electrolyte layer is disposed between the positive electrode layer and the negative electrode layer, and has an electrolyte solution that flows between adjacent solid electrolyte particles, wherein... The electrolyte layer includes oxide particles that are in contact with the solid electrolyte particles and adsorb the electrolyte solution.
2. The semi-solid battery according to claim 1, wherein, The electrolyte layer includes multiple solid electrolyte particles, multiple oxide particles, a void portion surrounded by the multiple solid electrolyte particles, and an electrolyte solution located in a portion of the void portion.
3. The semi-solid-state battery according to claim 1, wherein, The electrolyte layer comprises oxide particles coated on the surface of the solid electrolyte particles and having a particle size smaller than that of the solid electrolyte particles.
4. The semi-solid battery according to claim 3, wherein, The electrolyte layer includes a predetermined number or fewer oxide particles coated on the surface of the solid electrolyte particles at predetermined intervals.
5. The semi-solid battery according to claim 3, wherein, The surface of the solid electrolyte particles includes an area coated with the oxide particles and an area not coated with the oxide particles.
6. The semi-solid-state battery according to claim 1, wherein, The oxide particles contain zirconium oxide or tungsten dioxide.
7. The semi-solid-state battery according to claim 1, wherein, The positive electrode layer includes oxide particles coated on the surface of the positive electrode active material, and the negative electrode layer includes oxide particles coated on the surface of the negative electrode active material.
8. The semi-solid battery according to claim 3, wherein, The volume of the oxide particles coated on the solid electrolyte particles is less than a predetermined proportion of the volume of the solid electrolyte particles.
9. The semi-solid battery according to claim 3, wherein, The solid electrolyte particles coated with the oxide particles are also contained in at least one of the positive electrode layer or the negative electrode layer.