Porous PVA coating modified diaphragm and preparation method thereof

• Main Authors: LEE DAEUL, ZHAO HAIYU, SHEN YADING
• Format: Patent
• Language: Chinese; English
• Published: 28.06.2022
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

The invention discloses a porous PVA coating modified diaphragm and a preparation method thereof. The diaphragm comprises a polyolefin base membrane and a porous PVA (Polyvinyl Alcohol) coating, wherein the polyolefin base film comprises one of a PP (Polypropylene) single-layer film, a PE (Polyethylene) single-layer film or a PP/PE multi-layer composite film; the polymerization degree of the porous PVA coating is 1000-3000, and the alcoholysis degree of the porous PVA coating is 80-100%. The preparation method of the diaphragm sequentially comprises the three steps of PVA dissolving, coating, coating hole forming and drying. The porous PVA coating modified diaphragm obtained by the invention is low in price and simple in process, the coating is firmly bonded with the base membrane, and the porous PVA coating modified diaphragm also has excellent electrolyte wettability, relatively high liquid absorption and retention rate and ionic conductivity, and has a wide application prospect in lithium ion batteries. 本发