In-situ electrochemical preparation method of ionic conductive glass
By introducing metal doped ions in ceramic -based solid -state electrolytes, and transformed into glass phase in the process of charging and discharge cycle, the interface impedance problem caused by poor contact between the ceramic base solid electrolyte and the battery positive electrode The charging performance.
Patent Information
- Application Number
- CN202411555616.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-04
- Publication Date
- 2025-01-28
AI Technical Summary
Poor contact between the ceramic-based solid electrolyte and the positive and negative electrodes of the battery leads to a large interface impedance, reducing the charging and discharging performance of the solid-state battery.
Through the introduction of metal doped ions in the ceramic -based solid -state electrolyte, the original position is transformed into a glass phase during the charging and discharge cycle, forming an open structure and sodium ionic conductive glass, expanding along the electrolyte and positive polar interface to improve interface contact.
The interface impedance is reduced and the charging and discharge performance of the solid battery is improved.
Smart Images
Figure CN119371080A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of solid electrolyte preparation and electrochemical energy storage, and relates to an in-situ electrochemical preparation method of ion conductive glass. Background Art
[0002] Ceramic-based solid electrolytes (SSEs) are solid ion conductor electrolytes used in lithium (or sodium, potassium, magnesium, aluminum, zinc, etc.) ion batteries. They can improve battery safety, solve problems such as leakage and flammability of organic electrolytes, and achieve higher power density and recyclability. Currently, there are many common types of ceramic-based solid electrolytes, including garnet, (anti) perovskite, lithium ion conductor, and sodium ion conductor. However, the poor contact between ceramic-based solid electrolytes and the positive and negative electrodes of the battery usually leads to a large interface impedance, thereby reducing the charge and discharge performance of the solid-state battery.
[0003] Studies have shown that the glass phase can connect ion transport between ceramic particles in solid electrolytes (Journal of Power Sources, 2022, 521: 230930.). However, glass is an amorphous solid material made of minerals, oxides, metals and other materials melted at high temperatures. Its common preparation methods include float method, melting method, sol-gel method and ion exchange method. At present, there is still a blank in the electrochemical preparation of glass. Summary of the invention
[0004] In view of the problem that the ceramic-based solid electrolyte and the positive and negative electrodes in the current solid-state battery have a large interface impedance due to poor contact, which reduces the charge and discharge performance of the solid-state battery, the present invention provides an in-situ electrochemical preparation method of ion-conductive glass. The present invention destroys the crystalline phase structure and transforms into an amorphous glass during the charge and discharge process; the glass with an open structure and sodium ion conductivity is formed along the interface between the electrolyte and the positive and negative electrodes, solving the contact problem, thereby reducing the interface impedance.
[0005] An in-situ electrochemical preparation method for ion conductive glass comprises the following steps: (1) Preparation of ion-doped ceramic-based solid electrolyte sheets; Preferably, a garnet-type, (inverse) perovskite-type, lithium-ion conductor-type or sodium-ion conductor-type solid electrolyte is prepared by a solid phase method, and a sodium-ion conductor-type ceramic-based solid electrolyte is further preferred.
[0006] (2) Assembling a battery by matching the ceramic-based solid electrolyte sheet prepared in step (1) with a positive / negative electrode; the positive / negative electrode is a lithium ion battery positive / negative electrode, a sodium ion battery positive / negative electrode, a zinc ion battery positive / negative electrode, or a potassium ion battery positive / negative electrode, and the battery is preferably a button battery, a soft-pack battery, or a cylindrical battery, and more preferably a button battery; (3) The battery assembled in step (2) is subjected to charge and discharge cycles to prepare glass in situ.
[0007] According to the preferred embodiment of the present invention, the ions selected for ion doping in step (1) are all metal ions that promote glass formation in the electrochemical process, preferably Cu(II), Mn(III) and Ni(III), and more preferably Mn(III).
[0008] According to a preferred embodiment of the present invention, the ion doping amount in step (1) is 1.25%-7.5% of the molar mass of the substituting ions, and more preferably 5%.
[0009] Preferably, according to the present invention, the positive / negative electrodes in step (2) are Na / Na symmetric electrodes or NMF / Na asymmetric electrodes.
[0010] Preferably, according to the present invention, the core structure of the assembled battery in step (2) is positive electrode-solid electrolyte-negative electrode, and a trace amount of electrolyte is added between the solid electrolyte and the electrodes, or no electrolyte is added.
[0011] Further preferably, in step (2), the amount of trace electrolyte added between the solid electrolyte and the electrode is 0.025-0.1 mL.
[0012] Preferably, according to the present invention, the charge-discharge cycle in step (3) is a constant current charge-discharge cycle.
[0013] Further preferably, the current density of the charge-discharge cycle in step (3) is 0.1-10 mA / cm -2 , preferably 0.5-3.0 mA / cm -2 , more preferably 1 mA / cm -2 ; The charging and discharging time of each cycle is 0.1-2 h, preferably 0.5 h.
[0014] Preferably, according to the present invention, when the positive / negative electrodes in step (2) are Na / Na symmetric batteries, the charge and discharge cycle in step (3) is a constant current-limited time charge and discharge cycle; when the positive / negative electrodes in step (2) are NMF / Na asymmetric batteries, the charge and discharge cycle in step (3) is a constant current-limited voltage charge and discharge cycle.
[0015] The present invention also includes the use of the glass obtained by the in-situ electrochemical preparation method of the above-mentioned ion conductive glass in the interface modification of solid-state batteries.
[0016] Terminology In-situ electrochemical preparation of glass: During the battery charging and discharging process, some crystals in the solid electrolyte are directly converted into amorphous glass at their original positions in the battery.
[0017] Solid-state battery interface modification: The formed glass expands along the interface between the electrode and the electrolyte, strengthening the interface contact, forming a low-impedance interface, and realizing the interface modification of the solid-state battery.
[0018] Beneficial effects of the present invention The present invention introduces metal doping ions into a ceramic-based solid electrolyte, which is in situ transformed into a glass phase during the charge and discharge cycle of the assembled solid-state battery. Due to the volume expansion during the transformation from the crystalline phase to the amorphous phase, good interface contact is formed between the solid electrolyte and the electrode, thereby reducing the interface impedance and improving the performance of the solid-state battery. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 X-ray powder diffraction patterns of solid electrolytes obtained in Examples 1-4 and Comparative Example 1 of the present invention; Figure 2 The room temperature sodium ion conductivity of the solid electrolytes prepared in Examples 1-4 and Comparative Example 1 of the present invention; Figure 3 The constant current charge-discharge curve of the Na / Na symmetric battery assembled with solid electrolyte prepared in Example 3 of the present invention; Figure 4 The battery impedance curve of the solid electrolyte assembled Na / Na symmetric battery before cycling prepared in Example 3 of the present invention; Figure 5 The battery impedance curve after cycling of the Na / Na symmetric battery assembled with solid electrolyte prepared in Example 3 of the present invention; Figure 6 This is a SEM picture of the glass used to prepare the solid electrolyte assembled Na / Na symmetric battery obtained in Example 3 of the present invention; Figure 7 The DSC curve of the glass prepared by solid electrolyte assembled Na / Na symmetric battery prepared in Example 3 of the present invention; Figure 8 The charge and discharge curves of the NMF / Na asymmetric battery assembled with the solid electrolyte prepared in Example 5 of the present invention. DETAILED DESCRIPTION
[0020] The present invention is further described below by specific examples and comparative examples in conjunction with the accompanying drawings, but is not limited thereto. The raw materials used in the examples and comparative examples are all conventional raw materials.
[0021] Example 1 An in-situ electrochemical preparation method for ion conductive glass: (1) Preparation of Mn(III)-doped sodium ion conductor solid electrolyte Na by solid phase method 3 Zr 2 Si 2 PO 12 , to obtain Na3 Zr 1.975 Mn 0.025 Si 2 PO 12 (NZSPM0.025, substitution amount 1.25%) solid electrolyte sheet, XRD test results are as follows Figure 1 As shown, it proves that the NZSP crystal phase has been formed. The conductivity test results are shown in Figure 2 As shown, it is 7.23×10 -5 mxD -1 The conductivity before doping is 3.57×10 -5 mxD -1 , which is higher than that before doping.
[0022] (2) The ceramic-based solid electrolyte sheet prepared in step (1) was assembled into a 2032 symmetrical button cell with a Na / Na electrode, and 0.025 mL of electrolyte was added.
[0023] (3) The battery assembled in step (2) was charged at 1 mA / cm -2 The glass was prepared by carrying out charge and discharge cycles at a constant current density of , limiting the charge and discharge time of each cycle to 0.5 h.
[0024] After 30 cycles, the battery impedance decreased significantly, and battery disassembly testing confirmed the formation of a glass phase.
[0025] Example 2 An in-situ electrochemical preparation method for ion conductive glass: (1) Preparation of Mn(III)-doped sodium ion conductor solid electrolyte Na by solid phase method 3 Zr 2 Si 2 PO 12 , to obtain Na 3 Zr 1.95 Mn 0.05 Si 2 PO 12 (NZSPM0.05, substitution amount 2.5%) solid electrolyte sheet, XRD test results are as follows Figure 1 As shown, it proves that the NZSP crystal phase has been formed. The conductivity test results are shown in Figure 2 As shown, it is 1.02×10 -4 mxD -1 , the conductivity is improved compared with that before doping.
[0026] (2) The ceramic-based solid electrolyte sheet prepared in step (1) was assembled into a 2032 symmetrical button cell with a Na / Na electrode, and 0.1 mL of electrolyte was added.
[0027] (3) The battery assembled in step (2) was charged at 1 mA / cm -2 The glass was prepared by carrying out charge and discharge cycles at a constant current density of , limiting the charge and discharge time of each cycle to 0.5 h.
[0028] After 20 cycles, the battery impedance decreased significantly, and battery disassembly testing confirmed the formation of a glass phase.
[0029] Example 3 An in-situ electrochemical preparation method for ion conductive glass: (1) Preparation of Mn(III)-doped sodium ion conductor solid electrolyte Na by solid phase method 3 Zr 2 Si 2 PO 12 , to obtain Na 3 Zr 1.9 Mn 0.1 Si 2 PO 12 (NZSPM0.1, substitution amount 5%) solid electrolyte sheet, XRD test results are as follows Figure 1 As shown, it proves that the NZSP crystal phase has been formed. The conductivity test results are shown in Figure 2 As shown, it is 2.0×10 -4 mxD -1 , the conductivity is significantly improved compared with that before doping.
[0030] (2) Assembling a 2032 symmetrical button cell with the ceramic-based solid electrolyte sheet prepared in step (1) and the Na / Na electrode, and adding 0.05 mL of electrolyte; (3) The symmetrical battery assembled in step (2) was charged at 1 mA / cm -2 The charge and discharge cycles were carried out at a constant current density of , and the charge and discharge time of each cycle was limited to 0.5 h ( Figure 3 ), to prepare glass.
[0031] After 30 cycles, the battery impedance decreased significantly. Figure 4 , Figure 5 As shown. Disassembly battery testing proves the formation of glass phase, such as Figure 6 and Figure 7 shown.
[0032] Example 4 An in-situ electrochemical preparation method for ion conductive glass: (1) Preparation of Mn(III)-doped sodium ion conductor solid electrolyte Na by solid phase method 3 Zr 2 Si 2 PO 12 , to obtain Na3 Zr 1.85 Mn 0.15 Si 2 PO 12 (NZSPM0.15, substitution amount 7.5%) solid electrolyte sheet, XRD test results are as follows Figure 1 As shown, it proves that the NZSP crystal phase has been formed. The conductivity test results are shown in Figure 2 As shown, it is 1.2×10 -4 mxD -1 , the conductivity is improved compared with that before doping.
[0033] (2) The ceramic-based solid electrolyte sheet prepared in step (1) and the Na / Na electrode are assembled into a 2032 symmetrical button cell without adding an electrolyte.
[0034] (3) The battery assembled in step (2) was charged at 1 mA / cm -2 The glass was prepared by carrying out charge and discharge cycles at a constant current density of , limiting the charge and discharge time of each cycle to 0.5 h.
[0035] After 50 cycles, the battery impedance decreased significantly, and battery disassembly testing confirmed the formation of a glass phase.
[0036] Example 5 An in-situ electrochemical preparation method for ion conductive glass: (1) Preparation of Mn(III)-doped sodium ion conductor solid electrolyte Na by solid phase method 3 Zr 2 Si 2 PO 12 , to obtain Na 3 Zr 1.9 Mn 0.1 Si 2 PO 12 (NZSPM0.1, substitution amount 5%) solid electrolyte sheet, XRD test results are as follows Figure 1 As shown, it proves that the NZSP crystal phase has been formed. The conductivity test results are shown in Figure 2 As shown, it is 2.0×10 -4 mxD -1 , the conductivity is significantly improved compared with that before doping.
[0037] (2) The ceramic-based solid electrolyte sheet prepared in step (1) was assembled into a 2032 asymmetric button cell with the NMF / Na electrode, and 0.05 mL of electrolyte was added; (3) The asymmetric battery assembled in step (2) was charged and discharged at a voltage of 2-4 V and a rate of 0.1-0.5C. The performance was as follows: Figure 8 As shown, the performance is comparable to that of non-solid-state batteries.
[0038] Comparative Example 1 (1) Preparation of sodium ion conductor solid electrolyte Na by solid phase method 3 Zr 2 Si 2 PO 12 , to obtain Na 3 Zr 2 Si 2 PO 12 (NZSPM0) solid electrolyte sheet, XRD test results are as follows Figure 1 As shown, it proves that NZSP crystal phase (more impurities) has been formed, and the conductivity test result is 3.57×10 -5 mxD -1 ,like Figure 2 shown.
[0039] (2) The ceramic-based solid electrolyte sheet prepared in step (1) was assembled into a 2032 symmetrical button cell with a Na / Na electrode, and 0.025 mL of electrolyte was added.
[0040] (3) The battery assembled in step (2) was charged at 1 mA / cm -2 The charge and discharge cycles were carried out at a current density of 1.5 volts, and the charge and discharge time of each cycle was limited to 0.5 h. After 60 cycles, there was no significant change in the battery impedance, and no glass phase was found in the disassembly battery test.
Claims
1. An in-situ electrochemical preparation method of ion conductive glass, characterized in that: The preparation method comprises the following steps: (1) Preparation of ion-doped ceramic-based solid electrolyte sheets; (2) Assembling a battery by matching the ceramic-based solid electrolyte sheet prepared in step (1) with a positive / negative electrode; the positive / negative electrode is a lithium ion battery positive / negative electrode, a sodium ion battery positive / negative electrode, a zinc ion battery positive / negative electrode, or a potassium ion battery positive / negative electrode, and the battery is preferably a button battery, a soft-pack battery, or a cylindrical battery, and more preferably a button battery; (3) The battery assembled in step (2) is subjected to charge and discharge cycles to prepare glass in situ.
2. The preparation method according to claim 1, characterized in that: In step (1), a garnet-type, (inverse) perovskite-type, lithium-ion conductor-type or sodium-ion conductor-type ceramic-based solid electrolyte is prepared by a solid phase method, preferably a sodium-ion conductor-type ceramic-based solid electrolyte.
3. The preparation method according to claim 1, characterized in that: The ions selected for ion doping in step (1) are all metal ions that promote glass formation in the electrochemical process, preferably Cu(II), Mn(III) and Ni(III), and more preferably Mn(III). The ion doping amount is 1.25%-7.5% of the molar mass of the substituted ions, preferably 5%.
4. The preparation method according to claim 1, characterized in that: The positive / negative electrodes in step (2) are Na / Na symmetric electrodes or NMF / Na asymmetric electrodes.
5. The preparation method according to claim 1, characterized in that: The core structure of the assembled battery in step (2) is positive electrode-solid electrolyte-negative electrode, and a trace amount of electrolyte is added between the solid electrolyte and the electrode, or no electrolyte is added.
6. The preparation method according to claim 5, characterized in that The amount of trace electrolyte added between the solid electrolyte and the electrode in step (2) is 0.025-0.1 mL.
7. The preparation method according to claim 1, characterized in that: The charge-discharge cycle in step (3) is a constant current charge-discharge cycle.
8. The preparation method according to claim 7, characterized in that The current density of the charge-discharge cycle in step (3) is 0.1-10 mA / cm -2 , preferably 0.5-3.0 mA / cm -2 , more preferably 1 mA / cm -2 ; The charging and discharging time of each cycle is 0.1-2 h, preferably 0.5 h.
9. The preparation method according to claim 1, characterized in that: When the positive / negative electrodes in step (2) are Na / Na symmetric batteries, the charge and discharge cycle in step (3) is a constant current-limited time charge and discharge cycle; when the positive / negative electrodes in step (2) are NMF / Na asymmetric batteries, the charge and discharge cycle in step (3) is a constant current-limited voltage charge and discharge cycle.
10. Use of glass obtained by the in-situ electrochemical preparation method of ion conductive glass as described in claims 1 to 9 in solid-state battery interface modification.