Solid electrolyte membrane
By using a composite film structure consisting of a substrate layer, an electrolyte layer, and an interface modification layer in solid-state batteries, the problem of poor contact between the solid electrolyte and the electrode was solved, achieving the effects of reducing interface impedance and increasing battery energy density.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-24
- Publication Date
- 2026-03-24
AI Technical Summary
In solid-state batteries, poor contact between the solid electrolyte and the electrodes leads to high interfacial impedance, which affects battery energy efficiency and safety.
A solid electrolyte composite membrane is used, comprising a substrate layer, an electrolyte layer, and an interface modification layer. The substrate layer provides structural support, the electrolyte layer provides ion transport, and the interface modification layer reduces interface impedance.
It reduces the interfacial impedance between the solid electrolyte and the electrode, thereby improving the energy density and safety performance of the battery.
Smart Images
Figure CN224036402U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of electrolyte membrane, especially to a solid electrolyte membrane. BACKGROUND
[0002] In recent years, with the continuous development of lithium ion battery technology, lithium ion batteries have been widely used in all aspects of human social life. However, safety is an unavoidable focus problem in the large-scale promotion and high-performance development of lithium ion batteries. Lithium ion batteries mainly include positive electrode sheets, negative electrode sheets and electrolyte membranes, wherein the electrolyte membrane is arranged between the positive electrode sheet and the negative electrode sheet, and its main function is to isolate the positive electrode sheet and the negative electrode sheet to prevent the positive electrode sheet and the negative electrode sheet from directly contacting each other to cause battery short circuit, thereby avoiding causing battery thermal runaway and other safety problems. At the same time, the electrolyte membrane has a porous structure, and the porous structure of the electrolyte membrane enables lithium ions to be transmitted between the positive electrode sheet and the negative electrode sheet, so that the lithium ion battery can work normally.
[0003] Solid-state batteries are considered an important direction of next-generation battery technology due to their high energy density and high safety, but interface problems seriously hinder their commercialization process. Traditional liquid electrolytes can well wet the electrode surface to form a low impedance interface, while solid electrolytes cannot achieve similar interface contact. High interface impedance will increase the internal resistance of the battery, reduce energy efficiency and power output; Shorten the cycle life: poor interface contact will accelerate battery degradation and shorten the cycle life; Safety risk: interface problems may cause local current density to be too high, causing thermal runaway and other safety problems. In summary, the problem of high interface impedance caused by poor interface contact between solid electrolyte and electrode is mainly due to factors such as the rigid structure of solid electrolyte, volume change of electrode material, interface chemical instability and process limitations. This problem is one of the main bottlenecks of solid-state battery technology development, and solving the interface problem is crucial for the commercialization of solid-state batteries.
[0004] Therefore, it has important practical significance to provide a solid electrolyte membrane that can reduce interface impedance. UTILITY MODEL CONTENT
[0005] The utility model aims at a solid electrolyte membrane, which aims to solve the technical problem of high interface resistance caused by poor contact between solid electrolyte and electrode in the prior art solid-state battery.
[0006] In order to achieve the above utility model purpose, the utility model provides the following technical scheme:
[0007] The utility model provides a solid electrolyte membrane, the solid electrolyte membrane is solid electrolyte composite membrane, including substrate layer, electrolyte layer and interface modification layer;
[0008] The substrate layer is arranged on the upper side or / and lower side of the electrolyte layer, and the substrate layer has a single layer or multiple layers for providing structural support to the solid electrolyte membrane;
[0009] The electrolyte layer is arranged on the upper side or lower side of the interface modification layer for providing an ion transmission channel to the solid electrolyte membrane.
[0010] The interface modification layer is arranged on the bottom and top of the solid electrolyte membrane for reducing the interface impedance between the solid electrolyte and the electrode.
[0011] Further, the thickness of the solid electrolyte membrane is 8.0-15 μm.
[0012] Further, the porosity of the solid electrolyte membrane is 40-70%.
[0013] Further, the thicknesses of the substrate layer, the electrolyte layer and the interface modification layer satisfy the condition that the thickness of the electrolyte layer is less than the thickness of the substrate layer.
[0014] Further, the thickness of the solid electrolyte membrane satisfies one of the following conditions:
[0015] The porosity of the substrate layer is 40-70%;
[0016] The porosity of the interface modification layer is 30-70%.
[0017] Further, the substrate layer is a polyolefin single layer or a polyolefin multiple layer substrate layer.
[0018] Further, the substrate layer is a PE substrate layer or a PP substrate layer.
[0019] Further, the interface modification layer is an oxide interface modification layer.
[0020] Further, the electrolyte layer is one of a lithium titanium aluminum phosphate electrolyte layer, a lithium lanthanum zirconium oxide electrolyte layer, a lithium lanthanum zirconium tantalum oxide electrolyte layer, a lithium titanium aluminum phosphate-lithium lanthanum zirconium oxide composite electrolyte layer, a lithium titanium aluminum phosphate-lithium lanthanum zirconium tantalum oxide composite electrolyte layer or a lithium titanium aluminum phosphate-lithium lanthanum zirconium oxide-lithium lanthanum zirconium tantalum oxide composite electrolyte layer.
[0021] Compared with the prior art, the technical scheme of the utility model has the beneficial effects as follows:
[0022] The solid electrolyte membrane comprises a substrate layer, an electrolyte layer and an interface modification layer, the outer side of the solid electrolyte membrane is provided with the interface modification layer, the interface modification layer can improve the contact effect between the solid electrolyte and the electrode, reduce the interface impedance, the solid electrolyte membrane has a relatively thin thickness, the energy density of the battery can be improved when the solid electrolyte membrane is applied to the battery, and the safety performance is excellent. Attached Figure Description
[0023] Figure 1 This is a schematic diagram of the structure of the solid electrolyte membrane described in Embodiment 1 of this utility model;
[0024] Figure 2 This is a schematic diagram of the structure of the solid electrolyte membrane described in Embodiment 2 of this utility model;
[0025] Figure 3 This is a schematic diagram of the structure of the solid electrolyte membrane described in Embodiment 3 of this utility model;
[0026] In the figure: 1-substrate layer, 2-electrolyte layer, 3-interface modification layer. Detailed Implementation
[0027] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.
[0028] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0029] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.
[0030] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0031] This utility model provides a solid electrolyte membrane, which is a solid electrolyte composite membrane, including a substrate layer 1, an electrolyte layer 2 and an interface modification layer 3.
[0032] The substrate layer 1 is arranged on the upper side or lower side of the electrolyte layer 2, and is used for providing structural support for the solid electrolyte membrane;
[0033] The electrolyte layer 2 is arranged on the upper side or lower side of the interface modification layer 3, and is used for providing ion transmission function for the solid electrolyte membrane;
[0034] The interface modification layer 3 is arranged on the bottom and top of the solid electrolyte membrane, and is used for reducing the interface impedance between the solid electrolyte and the electrode.
[0035] In the utility model, the substrate layer 1 is the basis that solid electrolyte membrane can normally work, and the solid electrolyte membrane composed of electrolyte layer and interface modification layer is provided with structural support;The electrolyte layer includes electrolyte, and electrolyte layer 2 has excellent lithium ion transmission performance, improves the lithium ion transmission performance between positive electrode and negative electrode;The interface modification layer 3 is oxide interface modification layer, and specifically can preferably be aluminum oxide, lithium oxide or titanium oxide, and the interface modification layer 3 can improve the contact performance between solid electrolyte and positive and negative electrode sheet, reduce interface impedance, inhibit side reaction, and simultaneously enhance chemical stability.
[0036] In the utility model, the thickness of the solid electrolyte membrane is preferably 8.0~15 μm.
[0037] In the utility model, the porosity of the solid electrolyte membrane is preferably 40~70%.
[0038] In the utility model, the thickness of the substrate layer 1, electrolyte layer 2 and interface modification layer 3 preferably satisfies that the thickness of electrolyte layer 2≤the thickness of the substrate layer 1.
[0039] In the utility model, the thickness of the solid electrolyte membrane preferably satisfies one of the following conditions:
[0040] The porosity of the substrate layer 1 is 40~70%;
[0041] The porosity of the interface modification layer 3 is 30~70%.
[0042] In the utility model, the substrate layer 1 is polyolefin single-layer or polyolefin multi-layer substrate layer.
[0043] In the utility model, the substrate layer 1 is preferably PE substrate layer or PP substrate layer.
[0044] In the utility model, the interface modification layer 3 is preferably oxide interface modification layer, and specifically can preferably be lithium oxide, zirconium oxide or aluminum oxide.
[0045] In this invention, the electrolyte layer 2 is preferably one of the following: lithium titanium aluminum phosphate electrolyte layer, lithium lanthanum zirconium oxygen electrolyte layer, lithium lanthanum zirconium tantalum oxygen electrolyte layer, lithium titanium aluminum phosphate-lithium lanthanum zirconium oxygen composite electrolyte layer, lithium titanium aluminum phosphate-lithium lanthanum zirconium tantalum oxygen composite electrolyte layer, or lithium titanium aluminum phosphate-lithium lanthanum zirconium oxygen-lithium lanthanum zirconium tantalum oxygen composite electrolyte layer.
[0046] Unless otherwise specified, all raw materials required for preparation in this invention are commercially available products well known to those skilled in the art.
[0047] The technical solutions provided by this utility model will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of this utility model.
[0048] Example 1
[0049] See Figure 1 , Figure 1 In the solid electrolyte membrane shown, the interface modification layer 3 is disposed on the bottom and top surfaces of the solid electrolyte membrane. The solid electrolyte membrane consists of the interface modification layer 3, the electrolyte layer 2, the substrate layer 1, and the interface modification layer 3 in the stacking direction. In the solid electrolyte membrane, the substrate layer 1 provides structural support, making the structure of the solid electrolyte membrane stable and not easily deformed; the electrolyte layer 2 has ion transport function; and the interface modification layer 3 can improve the contact performance between the electrolyte and the electrode and reduce the interface impedance.
[0050] Example 2
[0051] See Figure 2 , Figure 1 In the solid electrolyte membrane shown, the interface modification layer 3 is disposed on the bottom and top surfaces of the solid electrolyte membrane. The solid electrolyte membrane consists of the interface modification layer 3, the substrate layer 1, the electrolyte layer 2, the substrate layer 1, and the interface modification layer 3 in the stacking direction. In this solid electrolyte membrane, the substrate layer 1 is a double layer. The double-layer configuration makes the structure of the solid electrolyte membrane more stable and less prone to deformation. The electrolyte layer 2 has the function of ion transport. The interface modification layer 3 can improve the contact performance between the electrolyte and the electrode and reduce the interface impedance.
[0052] Example 3
[0053] See Figure 3 , Figure 1The interface modification layer 3 is arranged on the bottom surface and the top of the solid electrolyte film, the solid electrolyte film is sequentially arranged with the interface modification layer 3, the electrolyte layer 2, the substrate layer 1, the substrate layer 1 and the interface modification layer 3 in the stacking direction, the substrate layer 1 is double-layered, the double-layered arrangement makes the structure of the solid electrolyte film more stable and less likely to be deformed, the electrolyte layer 2 has an ion transmission effect, and the interface modification layer 3 can relieve the contact performance between the electrolyte and the pole piece and reduce the interface impedance.
[0054] Those skilled in the art can understand that the above description is only preferred embodiments of the present application, and is not used to limit the present application, although the present application has been described in detail with reference to the foregoing embodiments, and those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or equivalently replace some technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A solid electrolyte membrane, characterized in that, The solid electrolyte membrane is a solid electrolyte composite membrane, comprising a substrate layer, an electrolyte layer, and an interface modification layer; The substrate layer is disposed on the upper side and / or lower side of the electrolyte layer, and the substrate layer has a single layer or multiple layers, for structural support of the solid electrolyte membrane; The electrolyte layer is disposed on the upper or lower side of the interface modification layer and is used to provide ion transport channels for the solid electrolyte membrane. The interface modification layer is disposed at the bottom and top of the solid electrolyte membrane to reduce the interfacial impedance between the solid electrolyte and the electrode.
2. The solid electrolyte membrane according to claim 1, characterized in that, The thickness of the solid electrolyte membrane is 8.0–15 μm.
3. The solid electrolyte membrane according to claim 1, characterized in that, The porosity of the solid electrolyte membrane is 40-70%.
4. The solid electrolyte membrane according to claim 1, characterized in that, The thicknesses of the substrate layer, electrolyte layer, and interface modification layer satisfy the following condition: the thickness of the electrolyte layer is less than or equal to the thickness of the substrate layer.
5. The solid electrolyte membrane according to claim 1, characterized in that, The thickness of the solid electrolyte membrane satisfies one of the following conditions: The porosity of the substrate layer is 40-70%; The porosity of the interface modification layer is 30-70%.
6. The solid electrolyte membrane according to claim 1, characterized in that, The substrate layer is a single-layer or multi-layer polyolefin substrate layer.
7. The solid electrolyte membrane according to claim 6, characterized in that, The substrate layer is a PE substrate layer or a PP substrate layer.
8. The solid electrolyte membrane according to claim 1, characterized in that, The interface modification layer is an oxide-based interface modification layer.
9. The solid electrolyte membrane according to claim 1, characterized in that, The electrolyte layer is one of the following: lithium titanium aluminum phosphate electrolyte layer, lithium lanthanum zirconium oxygen electrolyte layer, lithium lanthanum zirconium tantalum oxygen electrolyte layer, lithium titanium aluminum phosphate-lithium lanthanum zirconium oxygen composite electrolyte layer, lithium titanium aluminum phosphate-lithium lanthanum zirconium tantalum oxygen composite electrolyte layer, or lithium titanium aluminum phosphate-lithium lanthanum zirconium oxygen-lithium lanthanum zirconium tantalum oxygen composite electrolyte layer.