Integrated solid electrolyte unit and secondary battery
Through the processing and connection technology of large-size solid electrolyte materials, an integrated homogeneous electrolyte unit is formed, which solves the problem of particle gap and interface contact of solid electrolyte units, improves conductivity and battery safety, and extends battery life.
Patent Information
- Application Number
- CN202421653289.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-12
- Publication Date
- 2025-08-12
- Estimated Expiration
- 2034-07-12
AI Technical Summary
During the preparation process, existing solid electrolyte units have problems such as many particle gaps, poor interface contact, poor ionic conductivity and poor kinetic performance, and the polymer electrolyte conductivity is low and the electrochemical window is narrow.
Large-sized solid electrolyte materials of millimeter-level or above are used to form an integrated solid electrolyte layer. Through cutting, mold forming or other processing methods, combined with bonding, pressurization, heating or sintering technology, an integrated homogeneous overall structure is formed.
It improves the compactness and surface flatness of the electrolyte unit, reduces interface and side reactions, extends life, and improves the safety performance of the battery, reducing the risk of electrolyte leakage and explosion.
Smart Images
Figure CN223218325U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of secondary batteries, in particular to an integrated solid electrolyte unit and a preparation method thereof, and a secondary battery. Background Art
[0002] After liquid lithium-ion batteries were industrialized in 1991, they were first used in consumer batteries. The capacity of a single battery was not high, and the cycle life was relatively short. However, with the increasing application of lithium-ion battery technology in power and energy storage, people have placed increasingly higher demands on battery safety, energy density, and cycle life. However, the electrolyte of liquid lithium-ion batteries is liquid and highly active. It is unstable and easily decomposes and flammable at high temperatures. It also undergoes many side reactions with the positive and negative electrodes, which affects the battery life and easily leads to battery safety issues. Therefore, people hope to replace the liquid electrolyte with a solid one and develop solid-state electrolytes to improve high safety performance and cycle life. They can also use higher energy density positive and negative electrodes to increase energy density. They can also reduce battery system costs by implementing internal series connection and other methods.
[0003] In the preparation of solid-state batteries, the solid electrolyte unit is a crucial part. The current preparation of solid electrolyte units still has the following problems: 1) Oxide and sulfide solid electrolytes are still granular, with many gaps between the particles. At the same time, the corresponding positive and negative electrode surfaces are also in contact with each other, resulting in poor ionic conductivity. At the same time, a lot of pressure is usually required to achieve good conductivity. Even if sintering is performed again, the density and surface flatness of the material body are still poor, affecting the interface and kinetic properties. 2) Polymer solid electrolytes are soft and can be made into membranes for direct use. However, they have problems such as low conductivity and a narrow electrochemical window.
[0004] In view of the above-mentioned defects in the current preparation of solid electrolyte units, it is indeed necessary to provide a technical solution to solve the above problems. Utility Model Content
[0005] The purpose of the utility model is to provide an integrated solid electrolyte unit, which has no interface problems caused by granular combination inside the unit, is a homogeneous whole, has little specific surface area and interface, has small side reactions, has more stable electrical properties and longer life.
[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:
[0007] An integrated solid electrolyte unit comprises: a first solid electrolyte layer and a second solid electrolyte layer provided on a surface of the first solid electrolyte layer;
[0008] The first solid electrolyte layer and the second solid electrolyte layer are both integrated solid electrolyte layers formed by processing large-scale solid electrolyte materials of millimeter size or larger, and the chemical continuous dimension a in at least one direction in three-dimensional space is satisfied by the relationship: a≥0.5 mm;
[0009] The solid electrolyte material is at least one of a polymer solid electrolyte and an inorganic solid electrolyte; and the first and second solid electrolyte layers use different solid electrolyte materials. The integrated solid electrolyte unit of this application has excellent density and surface smoothness, resolving the problem of internal particles affecting interface and dynamic performance in the prior art. It has fewer interfaces, fewer side reactions, and a longer lifespan.
[0010] Preferably, it further comprises a third solid electrolyte layer provided on the other surface of the first solid electrolyte layer;
[0011] The third solid electrolyte layer is an integrated solid electrolyte layer formed by processing a large-scale solid electrolyte material of millimeter level or above, and its chemical continuous dimension in at least one direction in three-dimensional space is a, and a satisfies the relationship: a≥0.5mm;
[0012] The solid electrolyte material is at least one of a polymer solid electrolyte and an inorganic solid electrolyte.
[0013] Preferably, the processing method is cutting, mold forming or other processing methods.
[0014] Preferably, the inorganic solid electrolyte includes one of an oxide solid electrolyte material, a sulfide solid electrolyte material, a halide solid electrolyte material and a borohydride solid electrolyte material; the oxide solid electrolyte material includes garnet Li7La3Zr2O 12 , perovskite-type Li 0.33 La 0.557 TiO3 and LiSICON structured Li 1.3 Al 0.3 Ti 1.7 (PO4) 3; the sulfide solid electrolyte material includes Li 10 GeP2S 12 , Li2S-P2S5-LiCl; the halide solid electrolyte material includes one of Li3YCl6, Li3InCl6 and Li3ScCl6; the borohydride solid electrolyte material includes one of LiBH4, Li4(BH4)3I@SBA-15, LiBH4-S and LiBH4-Se.
[0015] Preferably, the polymer solid electrolyte includes one of PEO, polyacrylonitrile, polyvinyl alcohol, polyvinyl pyrrolidone and polyvinylidene fluoride.
[0016] Preferably, the first solid electrolyte layer, the second solid electrolyte layer and the third solid electrolyte layer have regular or irregular morphologies.
[0017] Preferably, the solid electrolyte layers are connected by bonding, pressurizing, heating or sintering.
[0018] Preferably, the chemical size is an atomic or molecular size.
[0019] The present invention also provides a method for preparing an integrated solid electrolyte unit, comprising the following steps:
[0020] Step 1: Making solid electrolyte particles into large-scale solid electrolyte materials of millimeter scale or above;
[0021] Step 2: Processing the large-sized solid electrolyte material into an integrated solid electrolyte layer;
[0022] Step 3: Hot-press and bond the integrated solid electrolyte layer to obtain an integrated solid electrolyte unit.
[0023] Preferably, in step 1, the large-scale solid electrolyte material of millimeter scale and above is made by at least one method selected from chemical synthesis, in-situ generation and high-temperature sintering.
[0024] The utility model also provides an integrated solid electrolyte unit, comprising a solid electrolyte layer and a coating layer coated on the surface of the solid electrolyte;
[0025] The solid electrolyte layer is an integrated solid electrolyte layer formed by processing a large-scale solid electrolyte material of millimeter size or above, and its chemical continuous dimension in at least one direction in three-dimensional space is a, and a satisfies the relationship: a≥0.5mm;
[0026] The solid electrolyte material is at least one of a polymer solid electrolyte and an inorganic solid electrolyte; and the solid electrolyte materials used in the solid electrolyte layer and the coating layer are different.
[0027] Preferably, the processing method is cutting, mold forming or other processing methods.
[0028] Preferably, the inorganic solid electrolyte includes one of an oxide solid electrolyte material, a sulfide solid electrolyte material, a halide solid electrolyte material and a borohydride solid electrolyte material; the oxide solid electrolyte material includes garnet Li7La3Zr2O 12 , perovskite-type Li0.33 La 0.557 TiO3 and LiSICON structured Li 1.3 Al 0.3 Ti 1.7 (PO4) 3; the sulfide solid electrolyte material includes Li 10 GeP2S 12 , Li2S-P2S5-LiCl; the halide solid electrolyte material includes one of Li3YCl6, Li3InCl6 and Li3ScCl6; the borohydride solid electrolyte material includes one of LiBH4, Li4(BH4)3I@SBA-15, LiBH4-S and LiBH4-Se; the polymer solid electrolyte includes one of PEO, polyacrylonitrile, polyvinyl alcohol, polyvinyl pyrrolidone and polyvinylidene fluoride.
[0029] Preferably, the solid electrolyte layer has a regular or irregular morphology.
[0030] Preferably, the chemical size is an atomic or molecular size.
[0031] The present invention also provides a method for preparing an integrated solid electrolyte unit, comprising the following steps:
[0032] Step 1: Making solid electrolyte particles into large-scale solid electrolyte materials of millimeter scale or above;
[0033] Step 2: Processing the large-sized solid electrolyte material into an integrated solid electrolyte layer;
[0034] Step three: coating the coating layer material on the solid electrolyte layer to obtain an integrated solid electrolyte unit.
[0035] Preferably, in step 1, the large-scale solid electrolyte material of millimeter scale and above is made by at least one method selected from chemical synthesis, in-situ generation and high-temperature sintering.
[0036] The utility model also provides a secondary battery, comprising an integrated negative electrode, an integrated positive electrode and the above-mentioned integrated solid electrolyte unit.
[0037] Without applying pressure between the units, the contact problem of the solid-solid interface is solved, which solves the problem of ionic conductivity and the kinetic problem to a certain extent.
[0038] Solid-state batteries offer improved safety. Firstly, the electrolyte is solid, which reduces reactivity and side reactions across the entire temperature range, resulting in improved safety. Secondly, similar to solar cells, even when used below 70-80% of capacity, safety issues such as lithium plating are avoided.
[0039] Compared with the existing technology, the beneficial effects of the present invention are: the integrated solid electrolyte unit of the present invention can have good electrical conductivity, reduce the amount of electrolyte used in the battery, improve the safety performance of the battery, and reduce the risks of battery electrolyte leakage, fire and explosion. BRIEF DESCRIPTION OF THE DRAWINGS
[0040] Figure 1 This is one of the structural schematic diagrams of an integrated solid electrolyte unit according to an embodiment of the present invention;
[0041] Figure 2 This is a second structural diagram of an integrated solid electrolyte unit according to an embodiment of the present invention;
[0042] Figure 3 This is a third structural diagram of an integrated solid electrolyte unit according to an embodiment of the present invention;
[0043] 1. First solid electrolyte layer; 2. Second solid electrolyte layer; 3. Third solid electrolyte layer; 4. Solid electrolyte layer; 5. Coating layer. DETAILED DESCRIPTION
[0044] To make the technical solutions and advantages of the present invention more clear, the following will be combined with specific embodiments to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.
[0045] According to a first aspect of the present invention, the present invention provides an integrated solid electrolyte unit, comprising: a first solid electrolyte layer and a second solid electrolyte layer disposed on a surface of the first solid electrolyte layer;
[0046] The first solid electrolyte layer and the second solid electrolyte layer are both integrated solid electrolyte layers formed by processing large-scale solid electrolyte materials of millimeter level or above, and their chemical continuous size in at least one direction in three-dimensional space is a, and a satisfies the relationship: a≥0.5mm; for example, a=0.8mm, a=1mm, a=2mm, a=3mm, a=5mm, a=7mm, a=9mm, a=15mm, a=19mm, a=22mm, a=23mm m, a=34mm, a=39mm, a=43mm, a=47mm, a=53mm, a=55mm, a=59mm, a=63mm, a=73mm, a=83mm, a=93mm, a=10 3mm, a=113mm, a=123mm, a=133mm, a=143mm, a=153mm, a=163mm, a=173mm, a=183mm, a=193mm, a=203mm;
[0047] The solid electrolyte material is at least one of a polymer solid electrolyte and an inorganic solid electrolyte; and the first solid electrolyte layer and the second solid electrolyte layer use different solid electrolyte materials. The integrated solid electrolyte unit of the present application has excellent density and surface smoothness, solving the problem of internal particles affecting the interface and dynamic performance in the prior art. It has fewer interfaces, fewer side reactions, and a longer lifespan.
[0048] In one embodiment of the present invention, the third solid electrolyte layer is further provided on the other surface of the first solid electrolyte layer;
[0049] The third solid electrolyte layer is an integrated solid electrolyte layer formed by processing large-scale solid electrolyte materials of millimeter level or above, and its chemical continuous size in at least one direction in three-dimensional space is a, and a satisfies the relationship: a ≥ 0.5 mm; for example, a = 0.8 mm, a = 1 mm, a = 2 mm, a = 3 mm, a = 5 mm, a = 7 mm, a = 9 mm, a = 15 mm, a = 19 mm, a = 22 mm, a = 23 mm, a = 34 mm. mm, a=39mm, a=43mm, a=47mm, a=53mm, a=55mm, a=59mm, a=63mm, a=73mm, a=83mm, a=93mm, a=103mm , a=113mm, a=123mm, a=133mm, a=143mm, a=153mm, a=163mm, a=173mm, a=183mm, a=193mm, a=203mm;
[0050] The solid electrolyte material is at least one of a polymer solid electrolyte and an inorganic solid electrolyte.
[0051] In an embodiment of the present invention, the processing method is cutting, mold forming or other processing methods.
[0052] In one embodiment of the present invention, the inorganic solid electrolyte includes one of an oxide solid electrolyte material, a sulfide solid electrolyte material, a halide solid electrolyte material and a borohydride solid electrolyte material; the oxide solid electrolyte material includes garnet Li7La3Zr2O 12 , perovskite-type Li 0.33 La 0.557 TiO3 and LiSICON structured Li 1.3 Al 0.3 Ti 1.7 (PO4)3; sulfide solid electrolyte materials include Li 10 GeP2S 12 , Li2S-P2S5-LiCl; the halide solid electrolyte material includes one of Li3YCl6, Li3InCl6 and Li3ScCl6; the borohydride solid electrolyte material includes one of LiBH4, Li4(BH4)3I@SBA-15, LiBH4-S and LiBH4-Se.
[0053] In one embodiment of the present invention, the polymer solid electrolyte includes one of PEO, polyacrylonitrile, polyvinyl alcohol, polyvinyl pyrrolidone and polyvinylidene fluoride.
[0054] In one embodiment of the present invention, the first solid electrolyte layer, the second solid electrolyte layer, and the third solid electrolyte layer have regular or irregular shapes, such as circular, triangular, or banana shapes.
[0055] In one embodiment of the present invention, the solid electrolyte layers are connected by bonding, pressurizing, heating, or sintering. The solid electrolyte layers are physically or chemically cross-linked, specifically by bonding, pressurizing, heating, or sintering, to form a solid electrolyte unit with tight connections and good interface properties.
[0056] In one embodiment of the present invention, the chemical size is an atomic-level size or a molecular-level size.
[0057] The present invention also provides a method for preparing an integrated solid electrolyte unit, comprising the following steps:
[0058] Step 1: Making solid electrolyte particles into large-scale solid electrolyte materials of millimeter scale or above;
[0059] Step 2: Processing the large-sized solid electrolyte material into a solid electrolyte layer;
[0060] Step 3: Hot-press and bond the integrated solid electrolyte layer to obtain an integrated solid electrolyte unit.
[0061] In one embodiment of the present invention, in step one, the large-scale solid electrolyte material of millimeter scale and above is made by at least one method selected from chemical synthesis, in-situ generation and high-temperature sintering.
[0062] The utility model also provides an integrated solid electrolyte unit, comprising a solid electrolyte layer and a coating layer coated on the surface of the solid electrolyte;
[0063] The solid electrolyte layer is an integrated solid electrolyte layer formed by processing large-scale solid electrolyte materials of millimeter level or above, and its chemical continuous size in at least one direction in three-dimensional space is a, and a satisfies the relationship: a ≥ 0.5 mm; for example, it can be a = 0.8 mm, a = 1 mm, a = 2 mm, a = 3 mm, a = 5 mm, a = 7 mm, a = 9 mm, a = 15 mm, a = 19 mm, a = 22 mm, a = 23 mm, a = 34 mm m, a=39mm, a=43mm, a=47mm, a=53mm, a=55mm, a=59mm, a=63mm, a=73mm, a=83mm, a=93mm, a=103mm, a=113mm, a=123mm, a=133mm, a=143mm, a=153mm, a=163mm, a=173mm, a=183mm, a=193mm, a=203mm;
[0064] The solid electrolyte material is at least one of a polymer solid electrolyte and an inorganic solid electrolyte; and the solid electrolyte layer and the coating layer use different solid electrolyte materials. The integrated solid electrolyte unit of the present application is an integrated material, a homogeneous whole, with fewer interfaces, fewer side reactions, and a longer lifespan. It can be widely used in various secondary batteries such as lithium-ion batteries, sodium-ion batteries, and potassium-ion batteries.
[0065] In an embodiment of the present invention, the processing method is cutting, mold forming or other processing methods.
[0066] In one embodiment of the present invention, the inorganic solid electrolyte includes one of an oxide solid electrolyte material, a sulfide solid electrolyte material, a halide solid electrolyte material and a borohydride solid electrolyte material; the oxide solid electrolyte material includes garnet Li7La3Zr2O 12 , perovskite-type Li 0.33 La 0.557 TiO3 and LiSICON structured Li 1.3 Al 0.3Ti 1.7 (PO4) 3; the sulfide solid electrolyte material includes Li 10 GeP2S 12 , Li2S-P2S5-LiCl; the halide solid electrolyte material includes one of Li3YCl6, Li3InCl6, and Li3ScCl6; the borohydride solid electrolyte material includes one of LiBH4, Li4(BH4)3I@SBA-15, LiBH4-S, and LiBH4-Se. The polymer solid electrolyte includes one of PEO, polyacrylonitrile, polyvinyl alcohol, polyvinyl pyrrolidone, and polyvinylidene fluoride.
[0067] In one embodiment of the present invention, the solid electrolyte layer has a regular or irregular shape, such as a circle, a triangle, or a banana shape.
[0068] In one embodiment of the present invention, the chemical size is an atomic-level size or a molecular-level size.
[0069] The present invention also provides a method for preparing an integrated solid electrolyte unit, comprising the following steps:
[0070] Step 1: Making solid electrolyte particles into large-scale solid electrolyte materials of millimeter scale or above;
[0071] Step 2: Processing the large-sized solid electrolyte material into a solid electrolyte layer;
[0072] Step three: coating the coating layer material on the solid electrolyte layer to obtain an integrated solid electrolyte unit.
[0073] In one embodiment of the present invention, in step one, the large-scale solid electrolyte material of millimeter scale and above is made by at least one method selected from chemical synthesis, in-situ generation and high-temperature sintering.
[0074] The utility model also provides a secondary battery, comprising an integrated negative electrode, an integrated positive electrode and the above-mentioned integrated solid electrolyte unit.
[0075] Without applying pressure between the units, the contact problem of the solid-solid interface is solved, which solves the problem of ionic conductivity and the kinetic problem to a certain extent.
[0076] Secondary batteries can be liquid, semi-solid, or solid-state. Solid-state batteries offer improved safety. Firstly, the electrolyte is solid, which reduces reactivity and side reactions across the entire temperature range, resulting in improved safety. Secondly, like solar cells, even when used below 70-80% of capacity, safety issues such as lithium plating are avoided.
[0077] The present invention will be further described below through specific embodiments.
[0078] Example 1
[0079] Preparation of integrated solid electrolyte unit:
[0080] Step 1: Making solid electrolyte particles into large-scale solid electrolyte materials of millimeter scale or above;
[0081] Step 2: Processing the large-sized solid electrolyte material into a solid electrolyte layer;
[0082] Step 3: Hot-press and bond the integrated solid electrolyte layer to obtain an integrated solid electrolyte unit. Preparation of solid-state batteries:
[0083] The "sandwich" structure formed by stacking the integrated positive electrode, the integrated solid electrolyte unit, and the integrated negative electrode is then encapsulated to obtain a solid-state battery, in which the positive electrode active material is LiCoO2 and the negative electrode active material is graphite.
[0084] Table 1 shows the solid electrolyte materials of the solid electrolyte layers of Examples 1 to 32. The rest are the same as in Example 1 and will not be described again here.
[0085] Table 1
[0086]
[0087]
[0088]
[0089] Example 33
[0090] Preparation of integrated solid electrolyte unit:
[0091] Step 1: Making solid electrolyte particles into large-scale solid electrolyte materials of millimeter scale or above;
[0092] Step 2: Processing the large-sized solid electrolyte material into an integrated solid electrolyte layer;
[0093] Step three: coating the coating layer material on the solid electrolyte layer to obtain an integrated solid electrolyte unit.
[0094] Preparation of solid-state batteries:
[0095] The "sandwich" structure formed by stacking the integrated positive electrode, the integrated solid electrolyte unit, and the integrated negative electrode is then encapsulated to obtain a solid-state battery, in which the positive electrode active material is LiCoO2 and the negative electrode active material is graphite.
[0096] Table 2 shows the solid electrolyte materials of the solid electrolyte layer and the coating layer of Examples 33 to 52. The rest is the same as that of Example 33 and will not be repeated here.
[0097] Table 2
[0098]
[0099] Comparative Example 1
[0100] The difference from Example 1 is that the solid electrolyte of this embodiment is composed of PP base film and PP surface coated polyethylene oxide and Li 0.33 La 0.557 TiO3 is mixed to form a solid electrolyte;
[0101] The rest is the same as in Example 1, and the performance test will not be described here in detail:
[0102] The solid electrolytes and solid batteries of Examples 1 to 71 and Comparative Example 1 were subjected to battery performance tests. The results are shown in Table 3.
[0103] Table 3
[0104]
[0105]
[0106] As can be seen from Table 3, the performance test data of the solid-state batteries of Examples 1-52 are all better than those of Comparative Example 1, indicating that the solid-state batteries made with the integrated solid-state electrolyte unit of the present invention have a longer cycle life, proving that the integrated solid-state electrolyte unit is a homogeneous whole with no granular combination inside, a reduced specific surface area of the unit, few interfaces, and stable electrical properties.
[0107] As can be seen from Table 3, the electrical conductivity of the integrated solid electrolyte unit of the embodiment is relatively high, indicating that the integrated solid electrolyte unit of the present invention has good electrical conductivity, which can reduce the amount of electrolyte used in the battery, and also improve the safety performance of the battery, reducing the risks of battery electrolyte leakage, fire and explosion.
[0108] Based on the disclosure and teachings of the above description, those skilled in the art will be able to make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments described above. Any obvious improvements, substitutions, or modifications made by those skilled in the art based on the present invention fall within the scope of protection of the present invention. In addition, although certain specific terms are used in this description, these terms are for convenience only and do not constitute any limitation on the present invention.
Claims
1. An integrated solid electrolyte unit, characterized in that: include: a first solid electrolyte layer and a second solid electrolyte layer disposed on a surface of the first solid electrolyte layer; The first solid electrolyte layer and the second solid electrolyte layer are both integrated solid electrolyte layers formed by processing large-size solid electrolyte materials of millimeter level or above, and their chemical continuity dimension in at least one direction in three-dimensional space is a, and a satisfies the relationship: a≥0.5mm.
2. The integrated solid electrolyte unit according to claim 1, characterized in that: Also comprising a third solid electrolyte layer disposed on the other surface of the first solid electrolyte layer; The third solid electrolyte layer is an integrated solid electrolyte layer formed by processing large-scale solid electrolyte materials of millimeter level or above, and its chemical continuous dimension in at least one direction in three-dimensional space is a, and a satisfies the relationship: a≥0.5mm.
3. The integrated solid electrolyte unit according to claim 1 or 2, characterized in that: The solid electrolyte layers are connected by bonding, pressurizing, heating or sintering.
4. The integrated solid electrolyte unit according to claim 1 or 2, characterized in that: The chemical size is an atomic or molecular size.
5. An integrated solid electrolyte unit, characterized in that: comprising a solid electrolyte layer and a coating layer coated on the surface of the solid electrolyte; The solid electrolyte layer is an integrated solid electrolyte layer formed by processing large-scale solid electrolyte materials of millimeter level or above, and its chemical continuous dimension in at least one direction in three-dimensional space is a, and a satisfies the relationship: a≥0.5mm.
6. The integrated solid electrolyte unit according to claim 5, characterized in that: The chemical size is an atomic or molecular size.
7. A secondary battery, characterized in that: The invention comprises an integrated negative electrode, an integrated positive electrode and an integrated solid electrolyte unit according to any one of claims 1 to 6.