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CN-116190571-B - Dry electrode plate and preparation method and application thereof

CN116190571BCN 116190571 BCN116190571 BCN 116190571BCN-116190571-B

Abstract

The invention belongs to the technical field of electrode plates, and particularly relates to a dry electrode plate, a preparation method and application thereof. The preparation method comprises the steps of mixing a liquid binder, an active substance and a conductive agent to obtain a blocky solid, crushing plant fibers into plant fiber filaments with the length of 3-10mm, then mixing the plant fiber filaments with the blocky solid at a high speed to obtain a black solid, drying the black solid to obtain a dry electrode raw material, coating the dry electrode raw material on a current collector, and rolling to obtain a dry electrode plate. The invention largely maintains the uniformity of wet mixing, simultaneously maintains the advantages of dry pole pieces, does not need to adopt toxic solvent NMP, and does not need to use expensive coating machine. The invention adopts plant fiber as a substance for supporting the dry electrode film, adopts a binder as an electrode binder, and has the advantages of green and healthy two raw materials, environmental friendliness and lower cost.

Inventors

  • YUE MIN
  • HUANG SILIN
  • YANG SHENGLIN
  • LIU JUN
  • DONG SHIJIN

Assignees

  • 深圳市研一新材料有限责任公司

Dates

Publication Date
20260508
Application Date
20230321

Claims (11)

  1. 1. The preparation method of the dry electrode slice is characterized by comprising the following steps: s1, mixing a liquid binder, an active substance and a conductive agent to obtain a blocky solid; S2, crushing plant fibers into plant fiber filaments with the length of 3-10mm, and then mixing the plant fiber filaments with the massive solid to obtain black solid; s3, drying the black solid to obtain a dry electrode raw material; s4, coating the dry electrode raw material on a current collector, and rolling to obtain a dry electrode plate; In S1, the liquid binder includes one or two of sodium alginate aqueous solution or epoxy resin binder.
  2. 2. The method for preparing a dry electrode sheet according to claim 1, wherein the plant fiber comprises one or more of coconut fiber, flax fiber, bamboo fiber, cotton fiber.
  3. 3. The method for preparing the dry electrode slice according to claim 1, wherein the mass fraction of the sodium alginate aqueous solution is 8-15%.
  4. 4. A method of producing a dry electrode sheet according to any one of claims 1 to 3, wherein in S1 and S2, when the liquid binder is an aqueous sodium alginate solution, the amount of the plant fiber is 1 to 5% by weight, the amount of the solute of the liquid binder is 1 to 5% by weight, the amount of the active material is 87 to 97% by weight, and the amount of the conductive agent is 1 to 3% by weight based on the total mass of the plant fiber, the solute of the liquid binder, the active material and the conductive agent; Or when the liquid binder is an epoxy resin binder, the amount of the plant fiber is 1-5% by weight, the amount of the liquid binder is 1-5% by weight, the amount of the active material is 87-97% by weight, and the amount of the conductive agent is 1-3% by weight, based on the total mass of the plant fiber, the liquid binder, the active material, and the conductive agent.
  5. 5. A method of preparing a dry electrode sheet according to any one of claims 1 to 3, wherein the active material comprises one of a positive electrode active material and a negative electrode active material; and/or the current collector comprises one of copper foil and aluminum foil.
  6. 6. A method of preparing a dry electrode sheet according to any one of claims 1-3, wherein in S1 the mixing time is 10-50min and the rotational speed is 1000-3000rpm; And/or in S2, the mixing time is 10-45min, and the rotating speed is 1000-3000rpm.
  7. 7. A method of preparing a dry electrode sheet according to any one of claims 1 to 3, wherein in S3 the temperature of the drying is 40 to 120 ℃; And/or, in S4, the temperature of the rolling is 40-120 ℃.
  8. 8. A method for preparing a dry electrode sheet according to any one of claims 1-3, wherein in S3, after said drying, further comprising grinding and crushing the material to obtain a dry electrode material; Drying the dry electrode raw material before S4; the drying treatment mode comprises at least one of heating and drying, vacuum drying and natural air drying.
  9. 9. A dry electrode sheet obtained by the manufacturing method of any one of claims 1 to 8.
  10. 10. An electrochemical energy storage device comprising the dry electrode sheet of claim 9.
  11. 11. An electrochemical energy storage device as in claim 10, wherein said electrochemical energy storage device comprises any one of a lithium ion battery, a sodium ion battery, a supercapacitor, a fuel cell, a rechargeable zinc air battery, or a solar cell.

Description

Dry electrode plate and preparation method and application thereof Technical Field The invention belongs to the technical field of electrode plates, and particularly relates to a dry electrode plate, a preparation method and application thereof. Background In the preparation process of a general wet electrode, a toxic solvent NMP is needed, the solvent is easy to cause larger influence on the environment, and the preparation process of the wet electrode is equivalent to that of a dry electrode, and a coating machine is needed for coating, so that the cost is higher. The dry electrode technology belongs to a solvent-free technology, a toxic solvent NMP is not required in the preparation process, the preparation process is simple, a coating step is not required, and the electrode manufacturing cost is reduced to a certain extent. The current mature dry electrode technology is PTFE technology, and mainly utilizes the property that PTFE can generate fibrosis to prepare a dry electrode film. For example, patent document CN115036462a discloses a pure dry sodium ion battery negative electrode, a preparation method and a battery thereof, the preparation method of the pure dry sodium ion battery negative electrode comprises the following steps of adding hard carbon powder into a planetary mixer, adding carbon black into artificial graphite powder for stirring, adding modified PTFE powder into the powder for stirring, fibrillating the mixed powder, putting the mixed powder into an open mill, extruding a continuous basic negative electrode sheet from a double roll, extending the basic negative electrode sheet through a multistage calender, and placing the extended sheet on two sides of an aluminum foil for thermal compounding, slitting and die cutting. Patent document CN114725320a discloses a method for preparing a dry pole piece, comprising the steps of preparing a first mixture containing an electrode active material and a conductive agent at a first temperature, preparing a second mixture containing the first mixture and a non-fibrillated binder at a second temperature, applying a shearing force to the second mixture to fibrillate the second mixture to prepare a third mixture, preheating the third mixture, applying preforming pressures in a plurality of directions to the preheated third mixture to prepare a preformed self-supporting electrode film, subjecting the preformed self-supporting electrode film to hot rolling thinning to prepare a self-supporting electrode film, and feeding the prepared self-supporting electrode film and a carbon-coated foil into a twin roll machine to obtain the dry pole piece. However, PTFE technology is required to be carried out in a high-temperature and high-pressure tank, and the process is relatively complex. Disclosure of Invention The invention provides a dry electrode plate, a preparation method and application thereof, and aims to solve the problems that in the prior art, a dry electrode technology adopts a PTFE technology and needs to be carried out in a high-temperature high-pressure tank, and the process is complex. Aiming at the technical defects, one of the purposes of the invention is to provide a preparation method of the dry electrode plate, the other purpose of the invention is to provide the dry electrode plate obtained by the preparation method, and the other purpose of the invention is to provide the application of the dry electrode plate. In a first aspect, the invention provides a method for preparing a dry electrode slice, comprising the following steps, S1, mixing a liquid binder, an active substance and a conductive agent to obtain a blocky solid; S2, crushing plant fibers into plant fiber filaments with the length of 3-10mm, and then mixing the plant fiber filaments with the massive solid to obtain black solid; s3, drying the black solid to obtain a dry electrode raw material; And S4, coating the dry electrode raw material on a current collector, and rolling to obtain the dry electrode pole piece. In the present invention, the plant fiber is used as a main substance for supporting the dry electrode film, and the binder is used as a secondary substance. The plant fiber has high cellulose content, good mechanical property and high elongation at break, and can play a certain supporting role. The plant fiber is the fiber extracted from the plant, and the raw material is environment-friendly and pollution-free, and does not harm the environment. The mechanical properties of the plant fiber are similar to those of the synthetic fiber, but the cost is lower. The binder mainly plays a role in binding the dry electrode film, and binds the plant fibers, the active substances and the current collector together to form a stable structure. In the preparation process, firstly, liquid binder, active substances and conductive agents are mixed at high speed, then plant fibers crushed by a crusher are added, high-speed mixing is carried out again, the mixed sample is in the stat