CN-116111102-B - Electrode plate, coating method thereof and battery

CN116111102BCN 116111102 BCN116111102 BCN 116111102BCN-116111102-B

Abstract

The invention discloses an electrode plate, a coating method and a battery thereof, wherein the electrode plate comprises a current collector and a slurry coating coated on the current collector, the slurry coating comprises a heat insulation material coating and a water-based slurry coating, the water-based slurry coating is coated on the current collector and covers the heat insulation material coating, the coating method comprises the steps of S1, designing a slurry coating area of the current collector according to a process specification, setting the width of the water-based slurry coating to be w, arranging the heat insulation material coating on two sides of the slurry coating, setting the coating width to be n, S2, uniformly coating the heat insulation material on the heat insulation coating area designed in the step S1, setting the coating thickness to be H, heating and drying, S3, uniformly coating the water-based slurry on the water-based slurry coating area designed in the step S1, setting the coating thickness to be H, and baking to finish the coating of the electrode plate. The coating method can reduce the heat conduction of the edge of the coating material layer, and further solve the problems of curling and cracking caused by baking and quick drying of the edge of the water-based pole piece.

Inventors

LU XIAOWEI
LIU LIANGHAI
WANG ZHIBIN
XU XIONGWEN
LI ZHONGYU

Assignees

湖南立方新能源科技有限责任公司

Dates

Publication Date: 20260505
Application Date: 20230216

Claims (4)

1. The electrode plate is characterized by comprising a current collector and slurry coatings coated on the current collector, wherein the slurry coatings comprise a heat insulation material coating and a water-based slurry coating, the water-based slurry coating is coated on the current collector and covers the heat insulation material coating, the width of the water-based slurry coating in the width direction of the current collector is w, the heat insulation material coating is arranged at two side edges of the water-based slurry coating, the width of the heat insulation material coating on each side is n, the water-based slurry coating is positioned in the middle of the current collector, the width n of the heat insulation material coating and the width w of the water-based slurry coating meet the relational expression of n=0.05-0.2 w, the heat insulation material is at least one of acrylic resin, polyurethane resin and polyamide resin, the thickness H of the water-based slurry coating and the thickness H of the heat insulation material coating meet the relational expression of h=0.03-0.14H, the width n of the heat insulation material coating is 1-20 mm, and the thickness H of the heat insulation material coating is 1-10 mu m.
2. The electrode sheet according to claim 1, wherein the heat insulating material and the aqueous slurry are coated by at least one of continuous coating and gap coating.
3. A coating method of an electrode sheet according to any one of claims 1 to 2 is characterized by comprising the following steps of S1, designing a slurry coating area of a current collector according to a process specification, wherein the width of an aqueous slurry coating is w, heat insulation material coatings are arranged on two sides of the slurry coating, the coating width is n, S2, uniformly coating the heat insulation material on the heat insulation coating area designed in the step S1, wherein the coating thickness is H, heating and drying, and S3, uniformly coating the aqueous slurry on the aqueous slurry coating area designed in the step S1, wherein the coating thickness is H, and baking to finish the coating of the electrode sheet.
4. A battery comprising a positive plate, a negative plate and a diaphragm spaced between the positive plate and the negative plate, wherein the positive plate and/or the negative plate is the electrode plate of any one of claims 1-2.

Description

Electrode plate, coating method thereof and battery Technical Field The invention relates to the technical field of batteries, in particular to an electrode plate, a coating method thereof and a battery. Background With the rapid development of energy storage, electric vehicles and portable electronic markets and the sustainable development of ecological environment protection, the requirements on the storage technology of the emerging energy sources are increasing. At present, a lithium ion battery which takes transition metal oxide as an anode and graphite as a cathode and a sodium ion battery which stores energy newly have wide application prospects in various fields of life. However, the sodium ion battery can use N-methyl pyrrolidone in the preparation process, the organic solvent has high cost, pollutes the environment, endangers the health of human bodies and does not meet the requirements of ecological environment environmental protection development. Therefore, developing an aqueous pole piece becomes a hot spot for the development of lithium/sodium ion batteries nowadays, and the development of a mature and stable aqueous pole piece process is urgently required. At present, a literature report exists on a lithium/sodium ion battery aqueous slurry process, but the aqueous slurry has the problems of coating baking curling, edge cracking and the like because the boiling point of solvent water is lower than that of oily solvent N-methyl pyrrolidone, the electrode plates are heated unevenly and the like in the coating process, and the two sides of the edge are evaporated to dryness more than the middle area. Some literature reports have addressed such problems from slurry additives, however, the improved aqueous slurries still present such problems during the coating process. Therefore, development of a novel aqueous pole piece coating process is urgently needed, and the problems of edge cracking and baking hemming caused by aqueous slurry in the coating process are solved. Disclosure of Invention Aiming at the defects of the prior art, the invention provides the electrode sheet, which solves the problems of baking hemming and edge cracking of aqueous slurry in the coating process and improves the applicability of the aqueous pole piece process in manufacturing lithium/sodium ion batteries by coating heat insulation materials on two sides of a current collector coating area. In order to achieve the above purpose, the present invention adopts the following technical scheme: The invention provides an electrode plate, which comprises a current collector and a slurry coating coated on the current collector, wherein the slurry coating comprises a heat insulation material coating and an aqueous slurry coating, and the aqueous slurry coating is coated on the current collector and covers the heat insulation material coating. Preferably, the width n of the heat insulation material coating and the width w of the aqueous slurry coating meet the relation of n=0.05-0.2w. Preferably, the heat insulating material is at least one of acrylic resin, polyurethane resin, and polyamide resin. Preferably, the heat insulating material and the aqueous slurry are coated by at least one of continuous coating and gap coating. Preferably, the thickness H of the aqueous slurry coating and the thickness H of the heat insulation material coating meet the relation of h=0.03-0.14H. Preferably, the width n of the heat insulation material coating is 1-20 mm. Preferably, the thickness h of the heat insulation material coating is 1-10 mu m. The invention also provides a coating method of the electrode slice, which comprises the following steps: S1, designing a slurry coating area of a current collector according to a process specification, wherein the width of a water-based slurry coating is w, heat-insulating material coatings are arranged on two sides of the slurry coating, and the width of the coating is n; S2, uniformly coating a heat-insulating material on the heat-insulating coating area designed in the step S1, wherein the coating thickness is h, and heating and drying are carried out; and S3, uniformly coating the aqueous slurry on the aqueous slurry coating area designed in the step S1, wherein the coating thickness is H, and performing a baking process to finish the coating of the electrode plate. Preferably, in step S1, the width n of the thermal insulation material coating is 1-20 mm. Preferably, in step S2, the thickness h of the thermal insulation coating is 1-10 μm. The invention also provides a battery, which comprises a positive plate, a negative plate and a diaphragm which is arranged between the positive plate and the negative plate, wherein the positive plate and/or the negative plate is/are the electrode plate. The electrode plate has the beneficial effects that the baking curling and cracking problems in the coating process are solved by coating the two sides of the slurry coating area with one layer of heat-insulati