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CN-122025442-A - Plant cellulose diaphragm and preparation method and application thereof

CN122025442ACN 122025442 ACN122025442 ACN 122025442ACN-122025442-A

Abstract

The invention discloses a plant cellulose diaphragm and a preparation method and application thereof. The plant cellulose diaphragm comprises, by mass, 60% -99% of cellulose fibers and 1% -40% of nano dielectric energy storage materials. The preparation method of the plant cellulose membrane comprises the following steps of 1) respectively preparing cellulose fiber slurry and nano dielectric energy storage material slurry, 2) uniformly mixing the cellulose fiber slurry and the nano dielectric energy storage material slurry, and then carrying out papermaking, solvent replacement and drying. The plant cellulose membrane has the advantages of small thickness, low interface impedance, uniform and adjustable pore structure, excellent electrochemical performance, good cycling stability, strong hydrophilicity, good insulativity, wide raw material sources, environmental friendliness, sustainability and the like, is suitable for super capacitors, and is simple in preparation method, high in production efficiency, low in production cost and suitable for large-scale industrial production and application.

Inventors

  • ZHONG LINXIN
  • JI QINGXUE
  • LI RUNSEN
  • PENG XINWEN

Assignees

  • 华南理工大学
  • 佛山市新宝思新材料科技有限公司

Dates

Publication Date
20260512
Application Date
20260115

Claims (10)

  1. 1. The plant cellulose diaphragm is characterized by comprising the following components in percentage by mass: 60% -99% of cellulose fiber; 1% -40% of nano dielectric energy storage material.
  2. 2. The plant cellulose membrane according to claim 1, wherein the cellulose fiber is at least one of wood fiber, bamboo fiber, and regenerated cellulose fiber.
  3. 3. The plant cellulose membrane according to claim 1 or 2, wherein the nano dielectric energy storage material is at least one of nano silica, nano barium titanate, nano titanium dioxide and nano zirconium dioxide.
  4. 4. The plant cellulose membrane according to claim 1 or 2, wherein the particle size of the nano dielectric energy storage material is 1nm to 1000nm.
  5. 5. The plant cellulose membrane according to claim 1 or 2, wherein the plant cellulose membrane has an areal density of 10g/m 2 ～50g/m 2 and a thickness of 10 μm to 80. Mu.m.
  6. 6. A method for preparing the plant cellulose membrane according to any one of claims 1 to 5, comprising the steps of: 1) Pulping and defibering cellulose fibers to prepare cellulose fiber slurry, and dispersing the nano dielectric energy storage material in water to prepare nano dielectric energy storage material slurry; 2) And uniformly mixing the cellulose fiber slurry and the nano dielectric energy storage material slurry, and then carrying out papermaking, solvent replacement and drying to obtain the plant cellulose diaphragm.
  7. 7. The method of claim 6, wherein the beating degree of the beating in the step 1) is 30-95 DEG SR.
  8. 8. The method according to claim 6, wherein the solvent used in the solvent substitution in the step 2) is at least one of ethanol, n-butanol, t-butanol and isopropanol.
  9. 9. The method according to claim 6 or 8, wherein the number of solvent substitutions in step 2) is 1 to 8, and the time of single solvent substitution is 1 to 60 minutes.
  10. 10. A supercapacitor characterized in that the separator used is the plant cellulose separator according to any one of claims 1 to 5.

Description

Plant cellulose diaphragm and preparation method and application thereof Technical Field The invention relates to the technical field of electrochemical energy storage, in particular to a plant cellulose diaphragm, a preparation method and application thereof. Background The super capacitor is an energy storage device between the traditional capacitor and the rechargeable battery, has high charge and discharge rate and long cycle life, and has very wide application prospect. The separator is an important component of the supercapacitor, and its performance directly affects the specific capacitance and cycle life of the supercapacitor. The plant cellulose membrane is a porous membrane prepared from natural plant fibers (such as wood fibers, cotton fibers, hemp fibers and the like), has the advantages of good wettability, high porosity, good thermal stability, high mechanical strength, good chemical stability, wide raw material sources, environmental friendliness, sustainability and the like, and is widely applied to the field of supercapacitors. However, the existing plant cellulose membrane has the defects of large thickness, large interface impedance, uneven pore size distribution and the like, and cannot completely meet the increasing practical application demands. Therefore, the development of the plant cellulose membrane with small thickness, low interface impedance, uniform and adjustable pore structure, excellent electrochemical performance, good cycle stability and low production cost has very important significance. Disclosure of Invention The invention aims to provide a plant cellulose diaphragm, and a preparation method and application thereof. The technical scheme adopted by the invention is as follows: the plant cellulose diaphragm comprises the following components in percentage by mass: 60% -99% of cellulose fiber; 1% -40% of nano dielectric energy storage material. Preferably, a plant cellulose membrane comprises the following components in percentage by mass: 70% -95% of cellulose fibers; 5% -30% of nano dielectric energy storage material. Preferably, the cellulose fiber is at least one of wood fiber, bamboo fiber and regenerated cellulose fiber. Preferably, the nano dielectric energy storage material is at least one of nano silicon dioxide, nano barium titanate, nano titanium dioxide and nano zirconium dioxide. Preferably, the particle size of the nano dielectric energy storage material is 1 nm-1000 nm. Preferably, the nano dielectric energy storage material is subjected to surface modification treatment by using a silane coupling agent. Preferably, the silane coupling agent is a silane coupling agent KH-550. Preferably, the plant cellulose membrane has an areal density of 10g/m 2～50g/m2 and a thickness of 10-80 μm. Further preferably, the plant cellulose membrane has an areal density of 15g/m 2～35g/m2 and a thickness of 25 μm to 50 μm. The preparation method of the plant cellulose membrane comprises the following steps: 1) Pulping and defibering cellulose fibers to prepare cellulose fiber slurry, and dispersing the nano dielectric energy storage material in water to prepare nano dielectric energy storage material slurry; 2) And uniformly mixing the cellulose fiber slurry and the nano dielectric energy storage material slurry, and then carrying out papermaking, solvent replacement and drying to obtain the plant cellulose diaphragm. Preferably, the beating degree of the beating in the step 1) is 30-95 DEG SR. Further preferably, the beating degree of the beating in the step 1) is 60 DEG SR-90 DEG SR. Preferably, the beating in step 1) is finished and high-pressure homogenization is also performed. Preferably, the number of times of high-pressure homogenization is 1 to 10. The number of times of high-pressure homogenization can directly influence the size of cellulose fibers, so that the porosity and thickness of the plant cellulose membrane can be regulated and controlled. Further preferably, the number of times of high-pressure homogenization is 1 to 4. Preferably, the high-pressure homogenization is performed under the condition that the pressure is 500-1500 bar, and the single high-pressure homogenization time is 1-5 min. Preferably, the replacement solvent adopted in the solvent replacement in the step 2) is at least one of ethanol, n-butanol, tertiary butanol and isopropanol. Preferably, the number of solvent replacement in the step 2) is 1 to 8, and the time of single solvent replacement is 1 to 60 minutes. Further preferably, the number of solvent replacement in the step 2) is 1 to 3, and the time of single solvent replacement is 1 to 30 minutes. Preferably, the drying in the step 2) is performed at a temperature of 60-90 ℃ for 5-30 min. A super capacitor adopts the membrane which is the plant cellulose membrane. The plant cellulose membrane has the advantages of small thickness, low interface impedance, uniform and adjustable pore structure, excellent electrochemical performance, goo