In-situ preparation and application of a heat-responsive polyether-type polymer solid-state electrolyte

Abstract

In-situ preparation and application of a thermoresponsive polyether polymer solid electrolyte, relating to a method for preparing a thermoresponsive polyether polymer solid electrolyte and its application in solid-state batteries. This invention utilizes the property of polyethers to depolymerize at high temperatures and repolymerize at low temperatures to achieve interface repair and electrolyte recycling in battery systems. The in-situ preparation and application of the thermoresponsive polyether polymer solid electrolyte of this invention consists of cyclic ethers, crosslinking agents, initiators, lithium salts, plasticizers, and additives. The polyether solid electrolyte obtained by this invention has thermoresponsive characteristics, can repair batteries with interface separation, reconstruct physical contacts, effectively restore and extend battery cycle life; furthermore, the depolymerized cyclic ether monomers can be collected by heating the cycled battery and reused in assembling new batteries. This electrolyte has broad application prospects.

Description

Technical Field

[0001] This invention belongs to the field of solid-state battery technology and relates to the in-situ preparation and application of a thermally responsive polyether polymer solid electrolyte. Background Technology

[0002] Lithium-ion batteries, as the most important electrochemical energy storage devices today, are widely used in consumer electronics, electric vehicles, and energy storage power stations. With increasing demands for energy density and safety, traditional liquid electrolytes, due to their inherent defects such as easy leakage and flammability, are unable to meet the needs of next-generation batteries. Solid-state electrolytes, especially polymer solid-state electrolytes, have become one of the key materials for future high-energy-density batteries due to their higher safety, better machinability, and potential for suppressing lithium dendrite formation. Polyether-type polymer solid-state electrolytes have received widespread attention in recent years due to their excellent ionic conductivity, good compatibility with lithium metal interfaces, and simple preparation processes.

[0003] However, existing polymer solid-state battery systems still face several serious challenges that restrict their commercial application. First, there is the long-term stability issue of the solid-solid interface. During battery cycling, the electrode active materials undergo volume changes, and uneven deposition and peeling of the lithium metal anode occur. These factors can lead to physical contact failure between the rigid or semi-rigid solid electrolyte and the electrode, creating interfacial voids. This interfacial separation drastically increases interfacial impedance, resulting in battery capacity decay and shortened lifespan. Second, there is the issue of the sustainability of electrolyte materials. From a life-cycle perspective, future large-scale energy storage systems must consider both environmental friendliness and economic efficiency. Currently, both liquid and solid electrolytes are difficult to efficiently recycle and reuse after battery disposal. This prevents valuable electrolyte materials from being recycled, increasing the environmental burden and raw material costs.

[0004] It is worth noting that polycyclic ethers possess a unique chemical property: when heated to a certain temperature, they can undergo depolymerization, reverting back to their monomeric cyclic ethers; conversely, when the temperature decreases and in the presence of an initiator, the monomers can recombine back into polyethers. This thermoresponsive characteristic has been primarily used in existing research to elucidate their polymerization mechanisms or to assess their thermal stability. However, to date, the enormous potential of this characteristic in solving systemic engineering challenges such as dynamic interfacial repair and closed-loop electrolyte recycling has not been revealed or utilized by any existing technology. Summary of the Invention

[0005] This invention aims to assemble solid-state batteries through in-situ polymerization. The core of this invention lies in the preparation of a thermally responsive polyether polymer solid electrolyte, thereby achieving the repair of battery interface separation and the efficient recycling and reuse of the electrolyte. This invention provides an in-situ preparation and application of a thermally responsive polyether polymer solid electrolyte.

[0006] The present invention relates to the in-situ preparation and application of a thermally responsive polyether polymer solid electrolyte, characterized in that the thermally responsive polyether solid electrolyte is composed of component A, component B, component C, component D, component E and component F.

[0007] Component A is at least one of 1,3,5-trioxane or 1,3-dioxane; Component B is at least one of the following: trifunctional aziridine crosslinking agent, tris(2-methylaziridine)phosphine oxide, triglycidyl isocyanurate, trimethylolpropane triglycidyl ether, glycerol triglycidyl ether, triglycidyl-p-aminophenol, 1,3-bis(3-glycidoxypropyl)-1,1,3,3-tetramethyldisiloxane, ethylene glycol diglycidyl ether, tetraethylene glycol diglycidyl ether, pentaerythritol diglycidyl ether, resorcinol diglycidyl ether, bisphenol A diglycidyl ether, or neopentyl glycol diglycidyl ether. Component C is at least one of tris(hexafluoroisopropyl) borate, lithium tetrafluoroborate, lithium oxalate borate, or tripentafluorophenylborane. Component D is at least one of lithium perchlorate, lithium bis(trifluoromethanesulfonate)imide, or lithium bis(fluoromethanesulfonate)imide. Component E is at least one of ethylene carbonate, diethyl carbonate, dimethyl carbonate, methyl ethyl carbonate, propylene carbonate, or ethylene glycol dimethyl ether. The component F is lithium dioxoborate.

[0008] The in-situ preparation of the thermally responsive polyether polymer solid electrolyte and the assembly of the solid battery of the present invention are carried out according to the following steps: I. Preparation of the mixed solution of component A-component B-component D-component F: Mix component A, component B, component D and component F, and stir for 5 min to 600 min at room temperature in the absence of air to obtain the mixed solution of component A-component B-component D-component F. II. Preparation of the mixed solution of component C and component E: Mix component C and component E and stir at 40°C in the absence of air for 30 min to 600 min to obtain the mixed solution of component C and component E. III. Preparation method of thermoresponsive polyether polymer solid electrolyte: The mixed solution of component C-component E prepared in step II is slowly added dropwise to the mixed solution of component A-component B-component D-component F prepared in step I while stirring. Stirring is carried out at room temperature in the absence of air for 5 min to 600 min. After mixing evenly, the precursor solution of polymer solid electrolyte is obtained. The precursor solution is allowed to stand at 40℃ to 60℃ for 24 h to 100 h to obtain thermoresponsive polyether polymer solid electrolyte.

[0009] IV. Application of thermally responsive polyether polymer solid electrolyte in solid-state batteries: The battery is assembled in a glove box using a positive electrode, a separator, and a negative electrode. The solid electrolyte precursor solution prepared in step three is injected into the battery and impregnated on the separator. Then, the battery is packaged using a battery packaging machine and allowed to stand at 40℃~60℃ for 24 h~100 h. The solid-state battery is obtained by in-situ polymerization, wherein the amount of solid electrolyte precursor solution used is 2 g / Ah ~ 15 g / Ah.

[0010] The beneficial effects of this invention are: This invention introduces an in-situ preparation method for a thermoresponsive polyether polymer solid electrolyte, resulting in a thermoresponsive polyether polymer solid electrolyte that enables the repair of battery interface separation and the efficient recovery and reuse of the electrolyte. This invention involves mild chemical reaction conditions, a simple method, and no side reactions.

[0011] The solid electrolyte prepared by this method has the following functions: (1) When the electrode / electrolyte interface separates during long-term cycling, heating the battery causes the polyether electrolyte to depolymerize into low-viscosity, high-flow-rate cyclic ether monomers. The monomers can flow and fill the separated interface, and then repolymerize at 60°C, thereby rebuilding the physical contact and effectively restoring and extending the battery cycle life. (2) The cycled battery is heated to completely depolymerize the polyether electrolyte, and the depolymerized monomers are collected for use in assembling new batteries, realizing the recycling of the electrolyte and significantly reducing costs and environmental burden. Attached Figure Description

[0012] Figure 1 The graph shows the thermal response characteristics of the solid electrolyte in Experiment 2. Figure 2 The test diagram shows the interface repair performance of the lithium iron phosphate solid-state battery in Experiment 3. Detailed Implementation

[0013] The present invention will be further described below with reference to the embodiments and accompanying drawings, but the present invention is not limited to these embodiments.

[0014] Specific Embodiment 1: A thermally responsive polyether polymer solid electrolyte of the present invention is specifically composed of component A, component B, component C, component D, component E and component F.

[0015] Component A is at least one of 1,3,5-trioxane or 1,3-dioxane; Component B is at least one of the following: trifunctional aziridine crosslinking agent, tris(2-methylaziridine)phosphine oxide, triglycidyl isocyanurate, trimethylolpropane triglycidyl ether, glycerol triglycidyl ether, triglycidyl-p-aminophenol, 1,3-bis(3-glycidoxypropyl)-1,1,3,3-tetramethyldisiloxane, ethylene glycol diglycidyl ether, tetraethylene glycol diglycidyl ether, pentaerythritol diglycidyl ether, resorcinol diglycidyl ether, bisphenol A diglycidyl ether, or neopentyl glycol diglycidyl ether. Component C is at least one of tris(hexafluoroisopropyl) borate, lithium tetrafluoroborate, lithium oxalate borate, or tripentafluorophenylborane. Component D is at least one of lithium perchlorate, lithium bis(trifluoromethanesulfonate)imide, or lithium bis(fluoromethanesulfonate)imide. Component E is at least one of ethylene carbonate, diethyl carbonate, dimethyl carbonate, methyl ethyl carbonate, propylene carbonate, or ethylene glycol dimethyl ether. The component F is lithium dioxoborate.

[0016] Specific Implementation Method Two: This implementation method is the in-situ preparation of the thermally responsive polyether polymer solid electrolyte and the assembly of the solid battery according to Specific Implementation Method One. Specifically, it is carried out according to the following steps: I. Preparation of the mixed solution of component A-component B-component D-component F: Mix component A, component B, component D and component F, and stir for 5 min to 600 min at room temperature in the absence of air to obtain the mixed solution of component A-component B-component D-component F. II. Preparation of the mixed solution of component C and component E: Mix component C and component E and stir at 40°C in the absence of air for 30 min to 600 min to obtain the mixed solution of component C and component E. III. Preparation method of thermoresponsive polyether polymer solid electrolyte: The mixed solution of component C-component E prepared in step II is slowly added dropwise to the mixed solution of component A-component B-component D-component F prepared in step I while stirring. Stirring is carried out at room temperature in the absence of air for 5 min to 600 min. After mixing evenly, the precursor solution of polymer solid electrolyte is obtained. The precursor solution is allowed to stand at 40℃ to 60℃ for 24 h to 100 h to obtain thermoresponsive polyether polymer solid electrolyte.

[0017] IV. Application of thermally responsive polyether polymer solid electrolyte in solid-state batteries: The battery is assembled in a glove box using a positive electrode, a separator, and a negative electrode. The solid electrolyte precursor solution prepared in step three is injected into the battery and impregnated on the separator. Then, the battery is packaged using a battery packaging machine and allowed to stand at 40℃~60℃ for 24 h~100 h. The solid-state battery is obtained by in-situ polymerization, wherein the amount of solid electrolyte precursor solution used is 2 g / Ah ~ 15 g / Ah.

[0018] Specific Implementation Method 3: This implementation method differs from Specific Implementation Method 2 in that the volume ratio of component A to component B is (9.5:0.5~1:9). Everything else is the same as in Specific Implementation Method 2.

[0019] Specific Implementation Method Four: This implementation method differs from Specific Implementation Method Two in that the molar concentration of component C in the precursor solution is (0.02 mol / L ~ 0.5 mol / L). Everything else is the same as in Specific Implementation Method Two.

[0020] Specific Implementation Method Five: This implementation method differs from Specific Implementation Method Two in that the molar concentration of component D in the precursor solution is (0.5 mol / L ~ 2.5 mol / L). Everything else is the same as in Specific Implementation Method Two.

[0021] Specific Implementation Method Six: This implementation method differs from Specific Implementation Method Two in that the volume percentage of component E in the precursor solution is (5% ~ 50%). Everything else is the same as in Specific Implementation Method Two.

[0022] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Method Two in that the molar concentration of component F in the precursor solution is (0.02 mol / L ~ 0.5 mol / L). Everything else is the same as in Specific Implementation Method Two.

[0023] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Method Two in that the diaphragm used is a PE diaphragm, cellulose diaphragm, glass fiber diaphragm, polyimide diaphragm, polyacrylonitrile diaphragm, or PE / PP / PE composite diaphragm. Everything else is the same as in Specific Implementation Method Two.

[0024] The invention was verified using the following experiments: Experiment 1: This experiment demonstrates a method for preparing a precursor solution of a polymer solid electrolyte, specifically carried out according to the following steps: Preparation of the precursor solution for the polymer solid electrolyte: 1,3-Dioxapentane, triglycidyl-p-aminophenol, lithium bis(trifluoromethanesulfonate)imide, and lithium dioxoborate were mixed and stirred for 30 min at room temperature in the absence of air to obtain precursor solution 1. Tris(hexafluoroisopropyl) borate and ethylene carbonate were mixed and stirred for 30 min at 40°C in the absence of air to obtain precursor solution 2. Precursor solution 2 was slowly added dropwise to precursor solution 1 while stirring, and the mixture was stirred for 10 min at room temperature in the absence of air. After homogeneity, the precursor solution for the polymer solid electrolyte was obtained. The volume ratio of 1,3-dioxopentane to triglycidyl-p-aminophenol is 9:1. The molar concentration of the tris(hexafluoroisopropyl) borate ester in the precursor solution is 0.3 mol / L; The molar concentration of lithium bis(trifluoromethanesulfonate)imide in the precursor solution is 2 mol / L; The volume percentage of the ethylene carbonate in the precursor solution is 10%. The molar concentration of lithium dioxoborate in the precursor solution is 0.5 mol / L.

[0025] Experiment 2: Using the precursor solution of the polymer solid electrolyte obtained in Experiment 1, a solid electrolyte was prepared and its thermal response characteristics were tested. The polymer solid electrolyte precursor solution was allowed to stand at 60°C for 120 h to obtain the polymer solid electrolyte. Its thermal response characteristics were verified by heating depolymerization and repolymerization at 60°C.

[0026] Figure 1 The figure shows the thermal response characteristics of the prepared polymer solid electrolyte in Experiment 2.

[0027] Experiment 3: In-situ solid-state lithium iron phosphate batteries were assembled using the precursor solution of the polymer solid electrolyte obtained in Experiment 1, and their interface repair performance was tested. I. Solid-state lithium iron phosphate battery assembly: Lithium iron phosphate, conductive carbon material, and binder were mixed in a mass ratio of 8:1:1, and then mixed with N-methylpyrrolidone to form a homogeneous slurry. The slurry was coated onto aluminum current collector foil and dried in a vacuum oven at 100 °C for 12 h. The dried aluminum foil was then cut into discs and assembled with a separator and lithium sheet. A polymer solid electrolyte precursor solution was then injected, and the mixture was encapsulated using a battery encapsulation machine. After standing at 60 °C for 24 h, a solid-state lithium iron phosphate battery was obtained and tested.

[0028] II. Interface Repair Performance Test: The charge-discharge tester manufactured by Xinwei Company was used to conduct charge-discharge tests and measure the cycle performance curve of the solid-state lithium iron phosphate battery. The charge-discharge voltage range was 2.5 V to 3.8 V.

[0029] Figure 2 To test the cycle performance curve of the lithium iron phosphate battery, as shown in the figure, the assembled lithium iron phosphate battery was heated to depolymerize and then repolymerized at 60°C after 750 cycles. It can be seen that the battery capacity has increased significantly, indicating that the interface separation caused by the volume change of the electrode material and the uneven deposition of lithium metal anode has been successfully repaired.

[0030] The above data fully demonstrate that the solid electrolyte prepared in this invention has thermal response characteristics, enabling the repair of battery interface separation and the efficient recycling and reuse of the electrolyte.

[0031] It should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. In-situ preparation and application of a thermally responsive polyether polymer solid electrolyte, characterized in that... The thermally responsive polyether solid electrolyte is composed of components A, B, C, D, E, and F. Component A is at least one of 1,3,5-trioxane or 1,3-dioxane; Component B is at least one of the following: trifunctional aziridine crosslinking agent, tris(2-methylaziridine)phosphine oxide, triglycidyl isocyanurate, trimethylolpropane triglycidyl ether, glycerol triglycidyl ether, triglycidyl-p-aminophenol, 1,3-bis(3-glycidoxypropyl)-1,1,3,3-tetramethyldisiloxane, ethylene glycol diglycidyl ether, tetraethylene glycol diglycidyl ether, pentaerythritol diglycidyl ether, resorcinol diglycidyl ether, bisphenol A diglycidyl ether, or neopentyl glycol diglycidyl ether. Component C is at least one of tris(hexafluoroisopropyl) borate, lithium tetrafluoroborate, lithium oxalate borate, or tripentafluorophenylborane. Component D is at least one of lithium perchlorate, lithium bis(trifluoromethanesulfonate)imide, or lithium bis(fluoromethanesulfonate)imide. Component E is at least one of ethylene carbonate, diethyl carbonate, dimethyl carbonate, methyl ethyl carbonate, propylene carbonate, or ethylene glycol dimethyl ether. The component F is lithium dioxoborate.

2. The in-situ preparation and application of a thermally responsive polyether polymer solid electrolyte as described in claim 1, characterized in that... The preparation and application of a thermally responsive polyether polymer solid electrolyte are carried out according to the following steps: I. Preparation of the mixed solution of component A-component B-component D-component F: Mix component A, component B, component D and component F, and stir for 5 min to 600 min at room temperature in the absence of air to obtain the mixed solution of component A-component B-component D-component F. II. Preparation of the mixed solution of component C and component E: Mix component C and component E and stir at 40°C in the absence of air for 30 min to 600 min to obtain the mixed solution of component C and component E. III. Preparation method of thermoresponsive polyether polymer solid electrolyte: The mixed solution of component C-component E prepared in step II is slowly added dropwise to the mixed solution of component A-component B-component D-component F prepared in step I while stirring. Stirring is carried out at room temperature in the absence of air for 5 min to 600 min. After mixing evenly, the precursor solution of polymer solid electrolyte is obtained. The precursor solution is allowed to stand at 40℃ to 60℃ for 24 h to 100 h to obtain thermoresponsive polyether polymer solid electrolyte. IV. Application of thermally responsive polyether polymer solid electrolyte in solid-state batteries: The battery is assembled in a glove box using a positive electrode, a separator, and a negative electrode. The solid electrolyte precursor solution prepared in step three is injected into the battery and impregnated on the separator. Then, the battery is packaged using a battery packaging machine and allowed to stand at 40℃~60℃ for 24 h~100 h. The solid-state battery is obtained by in-situ polymerization, wherein the amount of solid electrolyte precursor solution used is 2 g / Ah ~ 15 g / Ah.

3. The in-situ preparation and application of a thermally responsive polyether polymer solid electrolyte according to claim 2, characterized in that... The volume ratio of component A to component B is (9.5:0.5~1:9).

4. The in-situ preparation and application of a thermally responsive polyether polymer solid electrolyte according to claim 2, characterized in that... The molar concentration of component C in the precursor solution is (0.02 mol / L ~ 0.5 mol / L).

5. The in-situ preparation and application of a thermally responsive polyether polymer solid electrolyte according to claim 2, characterized in that... The molar concentration of component D in the precursor solution is (0.5 mol / L ~ 2.5 mol / L).

6. The in-situ preparation and application of a thermally responsive polyether polymer solid electrolyte according to claim 2, characterized in that... The volume percentage of component E in the precursor solution is (5% ~ 50%).

7. The in-situ preparation and application of a thermally responsive polyether polymer solid electrolyte according to claim 2, characterized in that... The molar concentration of component F in the precursor solution is (0.02 mol / L ~ 0.5 mol / L).

8. The in-situ preparation and application of a thermally responsive polyether polymer solid electrolyte according to claim 2, characterized in that... The membranes used are PE membranes, PP membranes, cellulose membranes, glass fiber membranes, polyimide membranes, polyacrylonitrile membranes, or PE / PP / PE composite membranes.

9. The application of the thermally responsive polyether polymer solid electrolyte according to claim 2 in the field of solid-state batteries.

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