Halide electrolyte membrane and preparation method thereof, solid-state lithium battery and application
By preparing an electrolyte membrane containing halide electrolytes, polydopamine, and lithium salts, the problems of cumbersome preparation steps and low air stability of halide electrolytes were solved, achieving high air stability and high ionic conductivity of the electrolyte, simplifying the preparation process and reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- PETROCHINA SHENZHEN NEW ENERGY RESEARCH INSTITUTE CO LTD
- Filing Date
- 2024-11-22
- Publication Date
- 2026-05-22
AI Technical Summary
Existing halide electrolytes have complicated preparation steps and low air stability, resulting in poor electrochemical performance.
A halide electrolyte membrane was prepared by combining a halide electrolyte, polydopamine, and lithium salt through mixing, coating, drying, and rolling. Polydopamine was converted into polydopamine under heat treatment and uniformly coated on the surface of the halide electrolyte, which improved air stability and simplified the preparation process.
This improves the air stability and ionic conductivity of halide electrolytes, simplifies the preparation process, and reduces production costs.
Smart Images
Figure CN122073250A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of lithium-ion battery technology, and in particular to a halide electrolyte membrane and its preparation method, solid-state lithium batteries and their applications. Background Technology
[0002] Lithium-ion batteries have a wide range of applications due to their high energy density, high operating voltage, long lifespan, high power, and portability. However, with increasing demands for battery energy density and safety, the conflict between the two has become increasingly prominent.
[0003] Currently, commercially available lithium-ion batteries contain flammable organic electrolyte components, resulting in poor stability. Consequently, high-energy-density lithium-ion batteries frequently experience spontaneous combustion and explosions. To address the trade-off between energy density and safety in lithium-ion batteries, solid-state batteries have emerged as a research focus, offering advantages such as high safety and potentially high energy density. While existing halide electrolytes possess excellent oxidation resistance, good stability with high-voltage cathode materials, and high ionic conductivity, they readily absorb moisture from the air, leading to a decline in their electrochemical performance.
[0004] Therefore, existing halide electrolytes suffer from cumbersome preparation steps or low air stability, resulting in poor electrochemical performance. There is an urgent need to provide a halide electrolyte membrane and its preparation method to improve these issues. Summary of the Invention
[0005] The main objective of this invention is to provide a halide electrolyte membrane and its preparation method, a solid-state lithium battery and its application, in order to solve the technical problems of cumbersome preparation steps or low air stability of halide electrolytes in the prior art, which leads to poor electrochemical performance.
[0006] To achieve the above objectives, according to one aspect of the present invention, a halide electrolyte membrane is provided comprising: a halide electrolyte, polydopamine, and a lithium salt, wherein the weight ratio of each component in the halide electrolyte membrane is: 90-99.8 wt% halide electrolyte, 0.1-10 wt% polydopamine, and 0.1-10 wt% lithium salt.
[0007] Furthermore, the weight of each component in the halide electrolyte membrane is: 95-98 wt% halide electrolyte, 1-3 wt% polydopamine and 1-2 wt% lithium salt.
[0008] Further, the halide electrolyte is selected from Li3InCl6 and / or Li2ZrCl4, and the lithium salt is selected from one or more of LiPF6, LiBF4, or LiTFSI; preferably, the thickness of the halide electrolyte membrane is 0.1–10 μm, and the ionic conductivity of the halide electrolyte membrane is (1–3) × 10⁻⁶. -3 S / cm.
[0009] To achieve the above objectives, according to one aspect of the present invention, a method for preparing a halide electrolyte membrane is provided. The method includes: mixing dopamine hydrochloride and lithium salt in an organic solvent once, adding a halide electrolyte and mixing again to obtain a mixed slurry, and then sequentially coating, drying and rolling to obtain a halide electrolyte membrane.
[0010] Furthermore, by weight percentage, the weight ratio of halide electrolyte, dopamine hydrochloride, and lithium salt is (90–99.8):(0.1–10):1.
[0011] Furthermore, the organic solvent is selected from one or more of anhydrous dichloromethane, trichloromethane, toluene, anisole, or acetonitrile.
[0012] Further, the coating process includes: uniformly coating the mixed slurry onto the surface of the PET substrate film, adjusting the coating height by changing the doctor blade height, with the coating height being 1–50 μm; preferably, the drying temperature is 80–150 °C, and the time is 3–12 h.
[0013] Furthermore, the rolling process is carried out in a rolling mill or a hot rolling mill, with a rolling pressure of 1 to 500 MPa, a processing temperature of 60 to 100°C, and a processing speed of 0.1 to 10 m / min.
[0014] According to another aspect of the present invention, a solid-state lithium battery is provided, comprising a halide electrolyte membrane obtained by the above-described method for preparing the halide electrolyte.
[0015] According to another aspect of the present invention, the above-mentioned solid-state lithium battery is provided for application in the fields of new energy vehicles, digital intelligence, or drones.
[0016] The halide electrolyte membrane prepared using the technical solution of this invention contains polydopamine, which exhibits high ionic conductivity. Furthermore, during the preparation process, dopamine hydrochloride raw material is heated to transform into polydopamine, which can uniformly coat the surface of the halide electrolyte, thereby isolating it from air and improving the air stability of the halide electrolyte. Simultaneously, polydopamine can also be used directly as a binder, eliminating the need for additional binders during preparation. This simplifies the preparation process and reduces production costs while simultaneously improving the ionic conductivity of the electrolyte. Attached Figure Description
[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. In the drawings:
[0018] Figure 1 A schematic diagram of the structure of the halide electrolyte membrane prepared according to Example 1 of the present invention is shown. Detailed Implementation
[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0020] As described in the background section of this invention, existing halide electrolytes suffer from cumbersome preparation steps or low air stability, resulting in poor electrochemical performance. Therefore, this invention provides a halide electrolyte membrane comprising: a halide electrolyte, polydopamine, and a lithium salt, wherein the weight percentages of each component in the halide electrolyte membrane are: 90–99.8 wt% halide electrolyte, 0.1–10 wt% polydopamine, and 0.1–10 wt% lithium salt.
[0021] Existing halide electrolyte membranes readily absorb moisture from the air, resulting in poor stability in air. This invention provides a halide electrolyte membrane containing polydopamine, which exhibits high ionic conductivity. Furthermore, during the preparation process, dopamine hydrochloride is added and heated to transform into polydopamine, which can uniformly coat the surface of the halide electrolyte. A schematic diagram of the specific structure is attached. Figure 1 As shown, this structure can isolate the electrolyte from air, thereby improving the air stability of the halide electrolyte. Simultaneously, polydopamine can be used directly as a binder, eliminating the need for additional binders during preparation. This simplifies the preparation process and reduces production costs while simultaneously improving the ionic conductivity of the electrolyte.
[0022] In a preferred embodiment, 95–98 wt% of a halide electrolyte, 1–3 wt% of polydopamine, and 1–2 wt% of a lithium salt are used to further improve the electrochemical performance and air stability of the halide electrolyte membrane. More preferably, the halide electrolyte is selected from Li3InCl6 and / or Li2ZrCl4, and the lithium salt is selected from one or more of LiPF6, LiBF4, or LiTFSI. Preferably, the thickness of the halide electrolyte membrane is 0.1–10 μm, and the ionic conductivity of the halide electrolyte membrane is (1–3) × 10⁻⁶. -3 S / cm.
[0023] In another aspect, the present invention provides a method for preparing a halide electrolyte membrane. The method includes: mixing dopamine hydrochloride and lithium salt in an organic solvent once, adding a halide electrolyte and mixing again to obtain a mixed slurry, and then sequentially coating, drying and rolling to obtain a halide electrolyte membrane.
[0024] Those skilled in the art first mix dopamine hydrochloride and lithium salt in an organic solvent, then add a halide electrolyte and mix again to obtain a mixed slurry. This mixed slurry is then sequentially coated, dried, and rolled to obtain a halide electrolyte membrane. This preparation method is simple, easy to operate, suitable for large-scale production, and has broad prospects for industrial application. The halide electrolyte membrane obtained using the above-described preparation method of this invention exhibits high air stability and superior electrochemical performance.
[0025] In a preferred embodiment, the weight ratio of the halide electrolyte, dopamine hydrochloride, and lithium salt is (90–99.8):(0.1–10):1, thereby further preparing a halide electrolyte membrane with excellent performance. Preferably, the organic solvent is selected from one or more of anhydrous dichloromethane, trichloromethane, toluene, anisole, or acetonitrile, to ensure more uniform mixing of the raw materials.
[0026] To further prepare a halide electrolyte membrane with superior electrochemical performance, the coating process includes: uniformly coating a mixed slurry onto the surface of a PET (polyethylene terephthalate) substrate membrane, adjusting the coating height by changing the doctor blade height to a height of 1–50 μm; preferably, the drying temperature is 80–150 °C and the time is 3–12 h, thereby converting the dopamine hydrochloride raw material into polydopamine upon heating, which can uniformly coat the surface of the halide electrolyte, thus isolating it from air and improving the air stability of the halide electrolyte.
[0027] In a preferred embodiment, the rolling process is carried out in a rolling mill or a hot rolling mill, with a rolling pressure of 1–500 MPa, more preferably 10–200 MPa, a processing temperature of 60–100 °C, and a processing speed of 0.1–10 m / min, more preferably 1–10 m / min. This further improves the structural stability, thermal stability, and electrochemical performance of the halide electrolyte membrane.
[0028] In another aspect, the present invention provides a solid-state lithium battery, including a halide electrolyte membrane, which is obtained by the above-described method for preparing the halide electrolyte.
[0029] In another aspect, the present invention provides a solid-state lithium battery for application in the fields of new energy vehicles, digital intelligence, or drones.
[0030] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.
[0031] Example 1
[0032] First, dopamine hydrochloride and lithium salt LiPF6 were mixed once in anhydrous dichloromethane at a stirring speed of 200 rpm for 5 hours at 30°C. Then, a halide electrolyte Li3InCl6 was added and mixed a second time at a stirring speed of 500 rpm for 5 hours at 30°C to obtain a mixed slurry. The weight ratio of halide electrolyte, dopamine hydrochloride, and lithium salt was 97:2:1. This mixed slurry was uniformly coated onto the surface of a PET substrate film, and the coating height was adjusted by changing the doctor blade height to a maximum of 10 μm. The film was then dried at 80°C for 5 hours, followed by rolling in a roller press at a pressure of 50 MPa, a temperature of 50°C, and a speed of 2 m / min. Finally, a halide electrolyte membrane was obtained. The weight composition of the halide electrolyte membrane was: 97 wt% halide electrolyte, 2 wt% polydopamine, and 1 wt% lithium salt. A schematic diagram of the structure of the electrolyte membrane is attached. Figure 1 As shown.
[0033] Example 2
[0034] The only difference from Example 1 is that the weight ratio of halide electrolyte, dopamine hydrochloride and lithium salt is 98:1:1.
[0035] Example 3
[0036] The only difference from Example 1 is that the weight ratio of halide electrolyte, dopamine hydrochloride and lithium salt is 96:3:1.
[0037] Example 4
[0038] The only difference from Example 1 is that the halide electrolyte used is Li2ZrCl6.
[0039] Example 5
[0040] The only difference from Example 1 is that the weight ratio of the halide electrolyte, dopamine hydrochloride, and lithium salt is 97:1:2.
[0041] Comparative Example 1
[0042] The only difference from Example 1 is that the raw materials contain only halide electrolytes, without the addition of dopamine hydrochloride and lithium salt.
[0043] Comparative Example 2
[0044] The only difference from Example 1 is that no lithium salt is added to the raw materials, and the weight ratio of halide electrolyte to dopamine hydrochloride is 97:3.
[0045] Performance testing
[0046] The ionic conductivity was tested using a micrometer screw gauge and an electrochemical workstation. The testing method was as follows: ① The halide electrolyte membrane was cut into uniform circular pieces with a diameter R of 1 cm; ② The thickness d was measured using a micrometer screw gauge; ③ The intrinsic resistance R was measured using the electrochemical workstation. The formula for calculating the ionic conductivity is: б=d / (R*лR) 2 / 4).
[0047] The electrolyte membranes prepared in the above examples and comparative examples were used as solid electrolytes. Lithium-indium alloy was used as the negative electrode, and NCM622 (nickel-cobalt-manganese ternary material 622) was used as the positive electrode. Solid-state batteries were assembled and tested. Charge-discharge tests were conducted at room temperature with a rate of 0.3C. The equipment used was a Blue Electric charge-discharge test cabinet. The test was stopped when the capacity decayed to 80%. The test results are shown in Table 1.
[0048] Table 1
[0049]
[0050] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:
[0051] Table 1 shows that the optimal thickness of the halide electrolyte membrane is 50 μm. Increasing the thickness leads to faster battery degradation due to the increased penetration into the solid-state battery, while decreasing the thickness allows lithium dendrites to easily puncture the halide electrolyte membrane, increasing the risk of short circuits and reducing battery cycle performance. In the comparative example, without dopamine, the prepared electrolyte membrane is thicker, which increases battery stability but reduces energy density and electrolyte membrane stability. Furthermore, without lithium salt in the comparative example, the electrolyte membrane has low ionic conductivity, resulting in poor battery performance.
[0052] In summary, the halide electrolyte membrane provided by this invention contains polydopamine, which exhibits high ionic conductivity. Furthermore, during the preparation process, the addition of dopamine hydrochloride raw material, which is heated to transform into polydopamine, allows it to uniformly coat the surface of the halide electrolyte, thereby isolating it from air and improving the air stability of the halide electrolyte. Simultaneously, polydopamine can also be used directly as a binder, eliminating the need for additional binders during preparation. This simplifies the preparation process and reduces production costs while simultaneously improving the ionic conductivity of the electrolyte.
[0053] While this specification contains numerous specific implementation details, these should not be construed as limiting the scope of any invention or the scope of the claims, but rather are primarily intended to describe features of specific embodiments of a particular invention. Certain features described in the various embodiments herein may also be implemented in combination in a single embodiment. Conversely, various features described in a single embodiment may also be implemented separately in various embodiments or in any suitable sub-combination. Furthermore, while features may function in certain combinations as described above and even initially claimed in this way, one or more features from a claimed combination may be removed from that combination in some cases, and a claimed combination may refer to a sub-combination or a variation thereof.
[0054] Similarly, although the operations are depicted in a specific order in the accompanying drawings, this should not be construed as requiring these operations to be performed in the specific order shown or sequentially, or requiring all illustrated operations to be performed to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Furthermore, the separation of various system modules and components in the above embodiments should not be construed as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.
[0055] Thus, specific embodiments of the subject matter have been described. Other embodiments are within the scope of the appended claims. In some cases, the actions recited in the claims may be performed in a different order and still achieve the desired result. Furthermore, the processes depicted in the drawings are not necessarily shown in a specific order or sequence to achieve the desired result. In some implementations, multitasking and parallel processing may be advantageous.
[0056] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0057] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.
Claims
1. A halide electrolyte membrane, characterized in that, The halide electrolyte membrane comprises: a halide electrolyte, polydopamine, and a lithium salt, wherein the weight of each component in the halide electrolyte membrane is: 90-99.8 wt% of the halide electrolyte, 0.1-10 wt% of the polydopamine, and 0.1-10 wt% of the lithium salt.
2. The halide electrolyte membrane according to claim 1, characterized in that, The weight of each component in the halide electrolyte membrane is: 95-98 wt% of the halide electrolyte, 1-3 wt% of the polydopamine, and 1-2 wt% of the lithium salt.
3. The halide electrolyte membrane according to claim 1 or 2, characterized in that, The halide electrolyte is selected from Li3InCl6 and / or Li2ZrCl6, and the lithium salt is selected from one or more of LiPF6, LiBF4 or LiTFSI; Preferably, the thickness of the halide electrolyte membrane is 0.1–10 μm, and the ionic conductivity of the halide electrolyte membrane is (1–3) × 10⁻⁶. -3 S / cm.
4. A method for preparing a halide electrolyte membrane according to any one of claims 1 to 3, characterized in that, The preparation method includes: mixing dopamine hydrochloride and lithium salt in an organic solvent once, adding a halide electrolyte and mixing a second time to obtain a mixed slurry, and then coating, drying and rolling processes in sequence to obtain the halide electrolyte membrane.
5. The preparation method according to claim 4, characterized in that, The weight ratio of the halide electrolyte, the dopamine hydrochloride, and the lithium salt is (90-99.8):(0.1-10):1, by weight percentage.
6. The preparation method according to claim 4, characterized in that, The organic solvent is selected from one or more of anhydrous dichloromethane, chloroform, toluene, anisole, or acetonitrile.
7. The preparation method according to claim 4, characterized in that, The coating process includes: uniformly coating the mixed slurry onto the surface of the PET substrate film, adjusting the coating height by changing the doctor blade height, with the coating height being 1–50 μm; Preferably, the drying process is carried out at a temperature of 80–150°C for 3–12 hours.
8. The preparation method according to claim 4, characterized in that, The rolling process is carried out in a rolling mill or a hot rolling mill, with a pressure of 1 to 500 MPa, a processing temperature of 60 to 100°C, and a processing speed of 0.1 to 10 m / min.
9. A solid-state lithium battery, comprising a halide electrolyte membrane, characterized in that, The halide electrolyte membrane is obtained by the method for preparing the halide electrolyte according to any one of claims 4 to 8.
10. An application of a solid-state lithium battery as described in claim 9 in the fields of new energy vehicles, digital intelligence, or drones.