Semi-solid gel electrolyte applied to fast-charging lithium battery and preparation method of semi-solid gel electrolyte

Abstract

The invention discloses a semi-solid gel electrolyte applied to a fast-charging lithium battery and a preparation method of the semi-solid gel electrolyte. The preparation method comprises the following steps: by taking triamino guanidine hydrochloride and PEG2-CHO as raw materials, water / 1, 4-dioxane as a solvent and acetic acid as a catalyst, carrying out solvothermal reaction to prepare a gel-state covalent organic framework material PEG-TGCl-COF, and replacing liquid in the gel-state COF with a liquid electrolyte to form the gel electrolyte PEG-TGCl-CGE. The gel electrolyte PEG-TGCl-CGE provided by the invention has excellent ionic conductivity, lithium ion transference number and wide electrochemical window, shows excellent fast charging performance while having relatively good safety performance of a semi-solid gel electrolyte, and is suitable for the field of lithium batteries.

Description

Technical Field

[0001] The present invention belongs to the field of semi-solid gel electrolytes for lithium batteries, and relates to a semi-solid gel electrolyte applied to fast-charging lithium batteries and a preparation method thereof. Background Art

[0002] The liquid electrolytes used in traditional lithium batteries have defects such as flammability, strong corrosiveness, and poor stability. For the emerging solid electrolytes, due to their poor interfacial contact and unsmooth internal ion pathways, their electrochemical performance is not satisfactory. Gel electrolytes are homogeneous systems formed by polymer networks, liquid plasticizers, and lithium salts. They provide a compromise, combining the high ionic conductivity of liquid electrolytes with the safety of solid electrolytes, and are very likely to become the next-generation high-performance and safe electrolyte materials. However, the structures of traditional gel electrolytes are random and disordered, making it difficult to form smooth and stable internal ion transport pathways, which limits their charge and discharge efficiency at high rates. For example, a recently reported bionic gel battery has a working rate of 0.5C, and the number of experimental cycles is within 300 cycles (Li H, Jing L, Wen G, et al. A Skin-Mimicked Polymer Gel Electrolyte for Stabilizing Lithium Metal Batteries[J]. Advanced Energy Materials, 2025.).

[0003] Covalent organic frameworks are crystalline materials with a periodic structure, which are formed by the sequential stacking of two-dimensional sheets at the microscopic level. Therefore, natural one-dimensional channels will be formed in the direction perpendicular to the sheets. Researchers have been constantly trying to utilize these channels as transport pathways for substances such as small molecules and ions. However, in the field of electrolyte materials, due to the fact that covalent organic framework materials are usually insoluble crystalline powders, their poor processability greatly limits their practical applications. Using covalent organic framework materials as the polymer network of gel electrolytes not only avoids their processing problems but also provides a clear structure and a clear ion conduction path for the gel (Liu Z, Zhang K, Huang G, et al. Highly processable covalent organic framework gel electrolyte enabled by side-chain engineering for lithium-ion batteries[J]. Angewandte Chemie International Edition, 2022.). However, since such work does not design covalent organic frameworks with a clear function of regulating ion conduction as the gel polymer network, but only relies on the regular pore characteristics of covalent organic frameworks to provide a clear structure for the gel, its rate performance is still not ideal. Summary of the Invention

[0004] One of the purposes of the present invention is to provide a covalent organic framework material PEG-TG Cl -COF with the function of regulating the conduction of anions and cations.

[0005] The covalent organic framework material PEG-TG Cl -COF with the function of regulating the conduction of anions and cations according to the present invention is a two-dimensional framework structure material formed by the Schiff base condensation reaction of guanidine hydrochloride triamine and an aldehyde compound grafted with PEG (PEG2-CHO). Its structural formula is as follows:

[0006]

[0007] The structural formula of the guanidine hydrochloride triamine described in the present invention is as follows:

[0008]

[0009] The structural formula of the PEG2-CHO described in the present invention is as follows:

[0010]

[0011] Another purpose of the present invention is to provide the above-mentioned covalent organic framework material PEG-TG Cl- Preparation method of COF, comprising the following steps:

[0012] Mix guanidine hydrochloride triamine and PEG2-CHO with a molar ratio of 2:3, then add a water / 1,4-dioxane mixed solution, and ultrasonically dissolve it. Then add an acetic acid solution, and ultrasonically treat the mixture until it gels. After that, quickly freeze it with liquid nitrogen and evacuate it, seal the tube with a flame torch, and heat and react at 120 ± 10 °C until a gel-like covalent organic framework material PEG-TG Cl - COF is obtained; in the water / 1,4-dioxane mixed solution, the volume ratio of water to 1,4-dioxane is 0.3:1, and the volume of the acetic acid solution is 1 / 20 - 1 / 5 of the volume of the water / 1,4-dioxane mixed solution, and the acetic acid concentration is 3 - 12 mol / L.

[0013] Furthermore, in the mixture, the concentration of guanidine hydrochloride triamine is 0.03 - 0.1 mol / L, preferably 0.035 mol / L; the concentration of PEG2-CHO is 0.03 - 0.1 mol / L, preferably 0.052 mol / L.

[0014] Furthermore, the volume of the acetic acid solution is 1 / 10 of the volume of the water / 1,4-dioxane mixed solution, and the acetic acid concentration is 6 mol / L.

[0015] Furthermore, the reaction time is 48 - 96 h, preferably 72 h.

[0016] Furthermore, for the gel-like covalent organic framework material PEG-TG Cl - COF, purify it with water and tetrahydrofuran by Soxhlet extraction, and finally freeze-dry it to obtain the covalent organic framework material PEG-TG Cl - COF solid.

[0017] The third object of the present invention is to provide a semi-solid gel electrolyte, which is PEG-TG Cl - CGE, and its composition includes a covalent organic framework material PEG-TG Cl - COF, a lithium salt, and an organic solvent.

[0018] The lithium salt described in the present invention is a lithium salt commonly used in the field of lithium batteries, including but not limited to lithium hexafluorophosphate (LiPF 6 ) and lithium perchlorate (LiClO 4 ) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), etc. In the specific implementation manner of the present invention, LiTFSI is taken as an example.

[0019] The organic solvents described in the present invention are organic solvents commonly used in the field of lithium batteries, preferably organic solvents with a boiling point ≥ 150 °C, including but not limited to ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), etc. In the specific embodiments of the present invention, PC is taken as an example.

[0020] A fourth object of the present invention is to provide a method for preparing the above-mentioned semi-solid gel electrolyte, comprising the following steps:

[0021] (1) Dissolve the lithium salt powder in an organic solvent to prepare a lithium salt solution;

[0022] (2) Place the gel-like covalent organic framework material PEG-TG Cl -COF in the lithium salt solution and replace it with fresh lithium salt solution at intervals, repeating this process until most of the remaining liquid and unreacted monomers in the gel-like covalent organic framework material PEG-TG Cl -COF are completely replaced;

[0023] (3) Place the covalent organic framework material PEG-TG Cl -COF gel obtained in step (2) in the lithium salt solution for high-temperature treatment. Utilize the boiling point difference between the residual 1,4-dioxane, water, and acetic acid low-boiling liquids in the gel and the high-boiling organic solvent to completely remove the remaining low-boiling liquids, and obtain the semi-solid gel electrolyte PEG-TG Cl -CGE.

[0024] Further, in step (1), the concentration of the lithium salt solution is 1 mol / L; in step (2), the replacement times are more than three; in step (3), the high-temperature treatment temperature is 110 - 150 °C, preferably 120 °C.

[0025] A fifth object of the present invention is to provide a semi-solid gel lithium battery, whose positive electrode is lithium iron phosphate (LFP), the negative electrode is lithium, and the electrolyte is the semi-solid gel electrolyte PEG-TG Cl -CGE.

[0026] The semi-solid gel lithium battery described in the present invention can be a lithium-ion battery or a lithium metal battery.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] (1) The present invention utilizes the highly designable nature of the covalent organic framework material, introducing cationic skeletons and PEG side chains into it. The synergistic effect of these two components enables it to be prepared in a gel state, getting rid of the limitation of traditional covalent organic frameworks as difficult-to-process powder materials. Benefiting from this, based on the gel-like covalent organic framework material PEG-TG ClThe self-supporting semi-solid gel electrolyte prepared from COF can give full play to the regular pore characteristics of covalent organic framework materials for ion conduction.

[0029] (2) The cationic skeleton of the covalent organic framework material of the present invention restricts the migration of lithium salt anions through Coulomb interaction. The PEG side chain provides jumping sites for lithium ions, inducing the directional transport of lithium ions and uniform deposition on the electrode surface. The cooperation of the two components regulates the transport of anions and cations respectively, improving the ionic conductivity of the electrolyte while maintaining a high lithium ion transference number, and greatly enhancing the ionic conduction performance of the electrolyte.

[0030] (3) The semi-solid gel electrolyte based on covalent organic framework material of the present invention has excellent high-rate cycling performance (i.e., fast charging performance) in lithium batteries. For example, the Li|PEG-TG Cl -CGE|LFP battery can stably operate for more than 2000 cycles at a rate of 10C. This performance almost surpasses all semi-solid gel electrolytes applied to this battery system, providing an idea for the design of gel electrolytes for fast charging performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 XRD comparison diagrams of materials prepared with different solvent ratios.

[0032] Figure 2 IR diagram of PEG-TG Cl -COF.

[0033] Figure 3 Digital image of PEG-TG Cl -CGE.

[0034] Figure 4 Variable-temperature electrochemical impedance spectrum of PEG-TG Cl -CGE.

[0035] Figure 5 Electrochemical impedance spectra and corresponding chronoamperometry curves of Li|PEG-TG Cl -CGE|Li battery before and after polarization.

[0036] Figure 6 Cycling performance diagram of Li|PEG-TG Cl -CGE|Li battery at 0.2 mA cm -2 and 25 °C.

[0037] Figure 7 Cycling curve of Li|PEG-TG Cl -CGE|LFP battery at a rate of 10C and 25 °C. DETAILED DESCRIPTION OF THE INVENTION

[0038] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0039] The guanidine hydrochloride triamine described in the present invention can be obtained by commercial purchase. PEG2-CHO can be prepared according to the literature by oneself (Wu M, Huang H, Xu B, et al. Poly(ethylene glycol)-functionalized 3D covalent organic frameworks as solid-state polyelectrolytes[J]. Rsc Advances, 2022.), and the specific synthesis route is as follows:

[0040]

[0041] The specific steps are as follows:

[0042] (1) Synthesis of 1,4-dibromo-2,5-bis(2-(2-methoxyethoxy)ethoxy)benzene: Add 2,5-dibromohydroquinone (2.14 g, 8.0 mmol), K 2 CO 3 (5.52 g, 40.0 mmol) and 1-bromo-2-(2-methoxyethoxy)ethane (2.4 mL, 17.5 mmol) into a 100 mL Schlenk flask respectively, and use a three-way tube to evacuate and fill argon into it three times. Then inject 40 mL of ultra-dry acetonitrile using a syringe. The reaction is stirred at 90 °C for 12 hours. After the reaction is completed, filter the mixture and concentrate the solution under vacuum. Add dichloromethane to redissolve it and then wash the solution with water three times. Separate the aqueous phase and the oil phase through a separatory funnel. Dry the oil phase with anhydrous Na 2 SO 4 , filter and concentrate. Use silica gel column chromatography (petroleum ether / ethyl acetate: 1 / 1) to obtain transparent crystals of 1,4-dibromo-2,5-bis(2-(2-methoxyethoxy)ethoxy)benzene (yield: 70%).

[0043] (2) Synthesis of PEG2-CHO: Add 1,4-dibromo-2,5-bis(2-(2-methoxyethoxy)ethoxy)benzene (2.36 g, 5 mmol), 4-formylphenylboronic acid (2.26 g, 15 mmol), tetrakis(triphenylphosphine)palladium (340 mg) and K 2 CO 3(2.07 g, 15 mmol) was added to a 100 mL Schlenk flask respectively. The flask was evacuated and backfilled with argon three times using a double manifold. Subsequently, anhydrous tetrahydrofuran (100 mL) and anaerobic water (20 mL) were injected using a syringe. The reactants were stirred overnight at 80 °C. After the reaction, the mixture was filtered and the solution was concentrated under vacuum. The residue was redissolved in dichloromethane and then washed with water three times. The aqueous phase and the organic phase were separated using a separatory funnel. The organic phase was dried with Na 2 SO 4 , filtered and concentrated. The crude product was purified by column chromatography (petroleum ether / ethyl acetate: 1 / 1) to obtain PEG2-CHO as a pale yellow powder (yield: 74%).

[0044] Example 1

[0045] Preparation method of PEG-TG Cl -COF is as follows:

[0046] Guanidine hydrochloride triamine (28 mg, 0.2 mmol) and PEG2-CHO (156.8 mg, 0.3 mmol) were mixed in a long-necked Pyrex tube (tube length 18 cm, neck length about 9 cm, volume about 20 mL). A mixed solution of 1,4-dioxane (2 mL), deionized water (0.6 mL) and 6 mol / L acetic acid solution (260 μL) was added. Then the mixture was sonicated for 15 minutes until it gelled. After that, the mixture in the tube was quickly frozen with liquid nitrogen and evacuated. The neck of the tube was sealed with a flame torch. Wait for the Pyrex tube to cool to room temperature and place it in an oven at 120 °C for reaction for 72 hours. The gel-like product covalent organic framework material PEG-TG Cl -COF was obtained. It was purified by Soxhlet extraction with water and tetrahydrofuran, and then freeze-dried to obtain the yellow solid covalent organic framework material PEG-TG Cl -COF with a yield of 85%. The reaction formula is as follows:

[0047]

[0048] Figure 1 For the comparison of XRD patterns of materials prepared with different solvent ratios, the XRD image of the product prepared when the volume ratio of 1,4-dioxane / water is 1 / 0.3 shows a weak characteristic peak at 3.1°, corresponding to the (100) crystal plane of the covalent organic framework. This proves its successful synthesis from the crystal characteristics of the material.

[0049] Figure 2 For the IR spectrum of PEG-TG Cl -COF, it can be seen that at 1094 and 2881 cm -1There is an obvious peak at each position, which are from C-O and C-H of the PEG chain respectively; the peak at 1214 cm -1 is from C-N of the backbone amino group; the peak at 1615 cm -1 is from C=N. This proves its successful synthesis from the molecular structure of the material.

[0050] Comparative Example 1

[0051] This comparative example is roughly the same as Example 1, except that the volume ratio of 1,4-dioxane to water is 1 / 0.1, that is, 1,4-dioxane (2 mL) and deionized water (0.2 mL) are added, and the monomer concentration remains unchanged. The product is an orange-yellow gel, and XRD is tested after being processed according to the steps in Example 1.

[0052] Figure 1 XRD patterns of materials prepared with different solvent ratios. The XRD image of the product prepared when the volume ratio of 1,4-dioxane / water is 1 / 0.1 does not show characteristic peaks. This indicates that the product at this solvent ratio is amorphous and the target covalent organic framework material cannot be synthesized.

[0053] Comparative Example 2

[0054] This comparative example is roughly the same as Example 1, except that the volume ratio of 1,4-dioxane to water is 1 / 0.5, that is, 1,4-dioxane (2 mL) and deionized water (1 mL) are added, and the monomer concentration remains unchanged. The product is a yellow powder, and XRD is tested after being processed according to the steps in Example 1.

[0055] Figure 1 XRD pattern comparison of materials prepared with different solvent ratios. The XRD image of the product prepared when the volume ratio of 1,4-dioxane / water is 1 / 0.5 does not show characteristic peaks. This indicates that the product at this solvent ratio is amorphous and the target covalent organic framework material cannot be synthesized.

[0056] Example 2

[0057] Gel electrolyte PEG-TG Cl -CGE preparation method, the specific steps are as follows:

[0058] Weigh 28.7 g of LiTFSI and dissolve it in 100 mL of PC to prepare a liquid electrolyte, and the concentration of LiTFSI is 1 mol / L. The gel-like covalent organic framework material PEG-TG Cl-The COF was placed statically in the liquid electrolyte. It was replaced with fresh liquid electrolyte every 24 hours. This process was repeated three times to replace most of the low-boiling-point liquids, including 1,4-dioxane, water, acetic acid, etc., as well as the monomers remaining during the reaction process. Finally, the gel was immersed in the liquid electrolyte and left overnight at 120 °C to completely remove the remaining solvents in the synthesis process while retaining the liquid electrolyte through the boiling point difference.

[0059] Figure 3 For the gel electrolyte PEG-TG Cl -Digital photo of CGE, it can be seen that the gel electrolyte PEG-TG Cl -CGE presented as an orange-yellow gel.

[0060] Example 3

[0061] Using the gel electrolyte PEG-TG Cl -CGE as the electrolyte, a battery with stainless steel (Ss) as the electrodes on both sides was assembled and the ionic conductivity was tested. The specific steps are as follows:

[0062] In a glove box filled with argon, assemble the Ss|PEG-TG Cl -CGE|Ss battery in the order of stainless steel sheet, gel electrolyte PEG-TG Cl -CGE, stainless steel sheet, and seal the battery mold with wax to ensure airtightness. Use Equation (1) to calculate the ionic conductivity (σ), where L represents the thickness of the electrolyte, S represents the effective contact area between the electrolyte and stainless steel, and R corresponds to the bulk electrolyte resistance. In the temperature range of 25 - 100 °C, use electrochemical impedance spectroscopy (EIS) to measure the ionic conductivity of n%-EBTp-M at a frequency range of 0.1 Hz to 1 MHz with an amplitude of 10 mV.

[0063]

[0064] Figure 4 For PEG-TG Cl -Variable-temperature electrochemical impedance spectrum of CGE. At 30 °C, the ionic conductivity of PEG-TG Cl -CGE was as high as 17.7 mS cm -1 , such a high conductivity indicates that the electrolyte can have sufficient lithium ions participating in the electrode reaction at a high current density, thus meeting the basic requirements of fast charging technology.

[0065] Example 4

[0066] Using the gel electrolyte PEG-TG Cl -CGE as the electrolyte, the lithium symmetric battery was assembled and the lithium ion transference number was tested. The specific steps are as follows:

[0067] In a glove box filled with argon, assemble the Li|PEG-TG Cl -CGE|Li battery in the order of lithium sheet, gel electrolyte PEG-TG Cl -CGE, and lithium sheet. Seal the battery mold with wax to ensure airtightness. Test the assembled Li|Li symmetric battery using chronoamperometry, where a polarization of 10 mV (ΔV) is applied to the battery for 3000 seconds. Record the polarization current, including the initial value (I bp ) and the steady-state value (I ap ). Measure the interfacial resistance before (R bp ) and after (R ap ) polarization using alternating current impedance. The test temperature is 60 °C. Subsequently, calculate the transference number (t + ) of Li Li + ) using the Bruce-Vincent-Evans equation (2).

[0068]

[0069] Figure 5 For the electrochemical impedance spectra and corresponding chronoamperometry curves of PEG-TG Cl -CGE before and after polarization. PEG-TG Cl -CGE exhibits a high t Li + of 0.71, indicating that ionic conduction in the electrolyte is mainly dominated by lithium ions, and the designed cationic framework plays a key role therein. This improves the stability of the battery during cycling.

[0070] Example 5

[0071] Assembly and cycling test of a lithium symmetric battery with the gel electrolyte PEG-TG Cl -CGE as the electrolyte are as follows:[[]]

[0072] The assembly method of the lithium symmetric battery is the same as that in Example 4. In the BlueTEC battery test system, test the cycling performance of the battery under the conditions of a current density of 0.2 mA cm -2 and 25 °C.

[0073] Figure 6 For the cycling performance of the lithium symmetric battery at 0.2 mA cm -2 and 25 °C. The results show that the lithium symmetric battery can operate stably for more than 2800 hours, and the overpotential is as low as ±54 mV. This proves that the specially designed covalent organic framework structure has a positive effect on the uniform deposition of lithium ions.

[0074] Example 6

[0075] Using the gel electrolyte PEG-TG Cl -CGE as the electrolyte, the assembly and testing of the semi-solid gel full cell are carried out as follows:

[0076] In a glove box filled with argon, assemble the Li|PEG-TG Cl -CGE|lithium iron phosphate (LFP) positive electrode in the order of lithium sheet, gel electrolyte PEG-TG Cl -CGE|LFP battery, and seal the battery mold with wax to ensure airtightness. In the Blue-Energy battery test system, test the charge-discharge performance of the battery under the conditions of a charge-discharge rate of 10C and 25°C, and the voltage range is 2.5V - 4.2V.

[0077] Figure 7 For the Li|PEG-TG Cl -CGE|LFP battery, the cycling curve at a rate of 10C. It can be seen that even at a rate as high as 10C, the battery using PEG-TG Cl -CGE as the electrolyte can maintain high specific capacity and cycling stability, and there is no obvious attenuation within 2000 cycles. This performance almost surpasses all semi-solid gel batteries used in this system, proving the superiority of the design of the present invention.

Claims

1. PEG-TG, a covalent organic framework material with the function of regulating anion and cation conduction Cl -COF, characterized in that The structural formula is as follows: 。 2. The covalent organic framework material PEG-TG according to claim 1 Cl -COF preparation method, characterized in that, The following steps are involved: The molar ratio of 2:3 of triaminoguanidine hydrochloride and PEG2-CHO was mixed, and then a water / 1,4-dioxane mixed solution was added, and ultrasonic treatment was performed to dissolve it. Then, an acetic acid solution was added, and the mixture was ultrasonically treated until it gelled. After that, it was quickly frozen with liquid nitrogen and evacuated, and the tube was sealed with a flame spray gun. The reaction was heated at 120±10°C until a gel-like covalent organic framework material PEG-TG was obtained. Cl -COF; in the water / 1,4-dioxane mixed solution, the volume ratio of water to 1,4-dioxane is 0.3:1, the volume of the acetic acid solution is 1 / 20 to 1 / 5 of the volume of the water / 1,4-dioxane mixed solution, and the acetic acid concentration is 3 to 12 mol / L.

3. The preparation method according to claim 2, characterized in that In the mixture, the concentration of triaminoguanidine hydrochloride is 0.03-0.1 mol / L, preferably 0.035 mol / L, the concentration of PEG2-CHO is 0.03-0.1 mol / L, preferably 0.052 mol / L; the volume of the acetic acid solution is 1 / 10 of the volume of the water / 1,4-dioxane mixed solution, and the concentration of acetic acid is 6 mol / L; the reaction time is 48-96 h, preferably 72 h.

4. The preparation method according to claim 2, characterized in that: The gel-like covalent organic framework material PEG-TG Cl -COF was purified by Soxhlet extraction with water and tetrahydrofuran, and finally freeze-dried to obtain the covalent organic framework material PEG-TG Cl -COF solid.

5. A semi-solid gel electrolyte PEG-TG Cl -CGE, characterized in that The composition includes the covalent organic framework material PEG-TG according to claim 1 Cl -COF, lithium salt and organic solvent.

6. The semi-solid gel electrolyte PEG-TG according to claim 5 Cl -CGE, characterized in that The lithium salt is LiPF6, LiClO4, LiTFSI, LiFSI; the organic solvent is ethylene carbonate, propylene carbonate or butylene carbonate.

7. The semi-solid gel electrolyte PEG-TG according to claim 5 or 6 Cl -CGE preparation method, characterized in that, The following steps are involved: (1) dissolving lithium salt powder in an organic solvent to prepare a lithium salt solution; (2) The gel-like covalent organic framework material PEG-TG Cl -COF is placed in a lithium salt solution and replaced with a fresh lithium salt solution at intervals. The process is repeated until the lithium salt solution completely replaces the gel-like covalent organic framework material PEG-TG Cl - Most of the liquid and unreacted monomers remaining in the COF; (3) The covalent organic framework material PEG-TG obtained in step (2) Cl The -COF gel was placed in a lithium salt solution for high temperature treatment, and the boiling point difference between the residual 1,4-dioxane, water and acetic acid low-boiling liquid and the high-boiling organic solvent in the gel was used to completely remove the residual low-boiling liquid to obtain a semi-solid gel electrolyte PEG-TG Cl -CGE.

8. The preparation method according to claim 7, characterized in that In step (1), the concentration of the lithium salt solution is 1 mol / L; in step (2), the number of replacements is three or more; in step (3), the high temperature treatment temperature is 110 to 150° C., preferably 120° C.

9. A semi-solid gel lithium battery, characterized in that: The positive electrode is lithium iron phosphate, the negative electrode is lithium, and the electrolyte is the semi-solid gel electrolyte PEG-TG as described in claim 5 or 6 Cl -CGE.

10. The semi-solid gel lithium battery according to claim 9, characterized in that: Lithium batteries are either lithium-ion batteries or lithium metal batteries.

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