CN-121416513-B - Sodium ion battery using fiber and ball copolymerized polypyrrole positive plate

Abstract

The invention belongs to the technical field of electrochemical energy storage devices, and relates to a sodium ion battery of a polypyrrole positive plate copolymerized by fibers and balls, which comprises a positive plate, a negative plate, a diaphragm and electrolyte. The material is prepared by using cetyl trimethyl ammonium bromide as a soft template and carrying out oxidative polymerization reaction on pyrrole monomers, ammonium persulfate and sodium paratoluenesulfonate under the ice bath condition, so that a three-dimensional conductive network formed by mutually interweaving nanofibers and nanospheres is formed. The structure has the advantages of rapid electronic conduction of the nanofiber and the capacity of enriching active sites and volume of the nanospheres, and the specific capacity, rate capability and cycling stability of the battery are obviously improved. The invention has simple process and low cost, and the capacity retention rate of the assembled battery exceeds 85% after 1000 times of circulation under the current density of 500mAh g ‑1 , thus being applicable to the field of large-scale energy storage.

Inventors

• ZHANG CHENGLIN
• HE XUEYANG
• CAO DAWEI
• LING YUHANG

Assignees

• 江苏大学

Dates

Publication Date

20260512

Application Date

20251229

Claims (13)

1. 1. A sodium ion battery using a fiber and ball copolymerized polypyrrole positive plate comprises a positive plate, a negative plate, a battery diaphragm arranged between the positive plate and the negative plate and electrolyte, and is characterized in that the positive plate is a fiber and ball copolymerized polypyrrole positive plate, a positive material layer of the positive plate comprises a fiber and ball copolymerized polypyrrole organic positive material, a microstructure of the fiber and ball copolymerized polypyrrole organic positive material is a three-dimensional network structure formed by interweaving polypyrrole nanofibers and polypyrrole nanospheres, the negative plate comprises sodium metal, alloy or carbon material capable of embedding sodium, the battery diaphragm is a polyolefin diaphragm, a glass fiber diaphragm or a polytetrafluoroethylene diaphragm, and the electrolyte comprises sodium salt and a solvent, and the solvent is an ether solvent or an ester solvent; the diameter of the polypyrrole nanofiber is 50-100 nm, and the diameter of the polypyrrole nanosphere is 50-100 nm; the polypyrrole positive plate copolymerized by the fibers and the balls is prepared by a method comprising the following steps: S1, premixing fiber and ball copolymerized polypyrrole organic positive electrode material powder, a conductive additive and an adhesive, adding N-methyl pyrrolidone, and uniformly stirring to prepare positive electrode slurry, wherein the positive electrode slurry comprises 8 parts of polypyrrole organic positive electrode material micro powder, 1 part of conductive additive and 1 part of adhesive in parts by mass; s2, coating positive electrode slurry on the surface of an aluminum foil, and vacuum drying to obtain the positive electrode plate; Wherein, the polypyrrole organic positive electrode material copolymerized by the fiber and the sphere is synthesized by a method comprising the following steps: A. Under ice bath condition, cetyl trimethyl ammonium bromide is taken as a soft template to be dissolved in hydrochloric acid solution, and the mixture is stirred until the cetyl trimethyl ammonium bromide is completely dissolved, so as to obtain a mixed solution; B. adding pyrrole monomers into a water phase containing ammonium persulfate and sodium paratoluenesulfonate, uniformly stirring, slowly dripping into the mixed solution in the step A, and carrying out polymerization reaction under ice bath conditions and in a dark place to obtain polypyrrole precipitate; C. And alternately washing the polypyrrole precipitate with deionized water and ethanol for a plurality of times, and vacuum drying to obtain the polypyrrole organic anode material copolymerized by fibers and spheres.
2. 2. The sodium ion battery using the polypyrrole positive plate copolymerized by fibers and balls according to claim 1, wherein in the step A, the ice bath temperature is 0-5 ℃ and the stirring time is 0.5-1.5 h.
3. 3. The sodium ion battery using a fiber and ball copolymerized polypyrrole positive electrode sheet as claimed in claim 2, wherein in the step A, the ice bath temperature is 0 ℃ and the stirring time is 1h.
4. 4. The sodium ion battery using fiber and ball copolymerization polypyrrole positive plate of claim 1, wherein in step A, the concentration of the hydrochloric acid solution is 1M, and the concentration of cetyl trimethyl ammonium bromide is 0.1-0.5M.
5. 5. The sodium ion battery using a fiber and sphere copolymerized polypyrrole positive electrode sheet according to claim 4, wherein: in step A, the concentration of cetyl trimethylammonium bromide is 0.2M.
6. 6. The sodium ion battery using the fiber and ball copolymerized polypyrrole positive plate of claim 1, wherein in the step B, the polymerization reaction temperature is kept at 0-5 ℃ and the reaction time is 1-12 h.
7. 7. The sodium ion battery using a fiber and sphere copolymerized polypyrrole positive electrode sheet as claimed in claim 6, wherein in the step B, the polymerization reaction temperature is 0 ℃ and the reaction time is 3h.
8. 8. The sodium ion battery using fiber and ball copolymerization polypyrrole positive plate according to claim 1, wherein in the step B, the molar ratio of pyrrole monomer, ammonium persulfate, sodium paratoluenesulfonate and cetyltrimethylammonium bromide is 1:0.5-3:0.5-3.
9. 9. The sodium ion battery using fiber and ball copolymerization polypyrrole positive electrode sheet according to claim 8, wherein in step B, the molar ratio of pyrrole monomer, ammonium persulfate, sodium paratoluenesulfonate and cetyltrimethylammonium bromide is 1:2.5:2:1.
10. 10. The sodium ion battery using the fiber and ball copolymerized polypyrrole positive plate of claim 1, wherein in the step C, the vacuum drying temperature is 60-100 ℃ and the drying time is 12-36 h.
11. 11. The sodium ion battery using fiber and ball copolymerization polypyrrole positive electrode sheet as claimed in claim 10, wherein in step C, the vacuum drying temperature is 80 ℃ and the drying time is 24h.
12. 12. The sodium ion battery using the fiber and ball copolymerized polypyrrole positive plate of claim 1, wherein the negative plate is graphite, hard carbon or soft carbon material, and the battery separator is polyethylene, polypropylene, glass fiber separator or polytetrafluoroethylene.
13. 13. The sodium ion battery using fiber and ball copolymerization polypyrrole positive plate of claim 1, wherein the electrolyte is characterized in that the ester solvent is one or more of ethylene carbonate, dimethyl carbonate and diethyl carbonate, the ether solvent is one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, tetrahydrofuran and dioxane, and the sodium salt is one or more of NaPF 6 、NaBF 4 、NaFSI、NaClO 4 .

Description

Sodium ion battery using fiber and ball copolymerized polypyrrole positive plate Technical Field The invention belongs to the technical field of electrochemical energy storage devices, and relates to a sodium ion battery, in particular to a sodium ion battery using a polypyrrole positive plate copolymerized by fibers and balls. Background With the rapid development of electric vehicles and large-scale energy storage systems, alkali metal batteries (such as lithium ion batteries, sodium ion batteries, potassium ion batteries, etc.) are receiving great attention as key electrochemical energy storage devices. Currently, the cathode materials of commercial alkali metal batteries mainly depend on inorganic compounds, such as layered oxides, polyanions and prussian blue materials. However, such inorganic materials often contain rare metal elements such as cobalt and nickel, which are not only costly, but also challenging for resource sustainability. Under the background, the organic positive electrode material becomes an important research direction for replacing the inorganic positive electrode material due to the advantages of wide raw material sources, good environmental compatibility, adjustable molecular structure and the like. Among them, polypyrrole, as a typical conductive polymer having a high theoretical specific capacity and excellent conductivity, exhibits potential as a high-performance cathode material. However, polypyrrole is susceptible to structural collapse and dissolution of active materials during battery cycling, resulting in poor cycling stability and sustained capacity decay. To enhance the electrochemical properties of polypyrrole, researchers have focused on improving ion transport and electron conduction behavior by manipulating their microscopic morphology and structure. For example, one-dimensional nanofiber structures can effectively shorten ion diffusion paths, while zero-dimensional nanosphere structures help to increase reactive sites and mitigate volume changes during charge and discharge. However, the existing synthesis method focuses on constructing polypyrrole with single morphology (such as pure fiber or pure spherical structure), and is difficult to simultaneously achieve fast ion/electron transmission and excellent structural stability, and multistage construction of copolymerization of fiber and sphere is not yet effectively realized, so that full play of comprehensive performance of the polypyrrole in a sodium ion battery is restricted. Disclosure of Invention Aiming at the problem that the cycling stability and the multiplying power performance of the polypyrrole positive electrode material are poor due to single morphology in the prior art, the invention aims to provide a sodium ion battery of a polypyrrole positive electrode plate copolymerized by fibers and balls. The specific capacity, the cycle life and the multiplying power performance of the battery are effectively improved by adopting the polypyrrole positive plate with the unique microstructure of fiber and sphere copolymerization. Technical proposal A sodium ion battery using fiber and ball copolymerized polypyrrole positive plate comprises a positive plate, a negative plate, a battery diaphragm arranged between the positive plate and the negative plate, and electrolyte; The anode plate is a polypyrrole anode plate copolymerized by fibers and balls, and the anode material layer comprises a polypyrrole organic anode material copolymerized by fibers and balls, wherein the microstructure of the polypyrrole organic anode material copolymerized by fibers and balls is a three-dimensional network structure formed by interweaving polypyrrole nanofibers and polypyrrole nanospheres; The negative electrode sheet comprises sodium metal, alloy or carbon material capable of embedding sodium; the battery diaphragm is a polyolefin diaphragm, a glass fiber diaphragm or a polytetrafluoroethylene diaphragm; the electrolyte comprises sodium salt and a solvent, wherein the solvent is an ether solvent or an ester solvent; The polypyrrole organic positive electrode material is characterized in that the microstructure of the polypyrrole organic positive electrode material is a three-dimensional network structure formed by interweaving polypyrrole nanofibers and polypyrrole nanospheres, wherein the diameter of the polypyrrole nanofibers is about 50-100 nm, and the diameter of the polypyrrole nanospheres is about 50-100 nm. According to the preferred disclosed example, the polypyrrole positive plate copolymerized by the fibers and the balls is prepared by a method comprising the following steps: S1, premixing fiber and ball copolymerized polypyrrole organic positive electrode material powder, a conductive additive and an adhesive, adding N-methyl pyrrolidone, and uniformly stirring to prepare positive electrode slurry, wherein the positive electrode slurry comprises 8 parts of polypyrrole organic positive electrode material micro powder,