The invention discloses a high-temperature-resistant water-soluble
aramid coating diaphragm and a preparation method thereof, and belongs to the technical field of battery diaphragms. The diaphragm is obtained by
coating the surface of a base membrane with water-soluble
aramid fiber slurry and performing cross-linking and
drying, the base membrane is a PE / PVA
composite membrane; the water-soluble
aramid fiber slurry is prepared from the following raw materials in parts by
mass: 10 to 20 parts of modified aramid
fiber polymer, 40 to 80 parts of deionized water, 3 to 6 parts of cosolvent and 5 to 8 parts of multi-
epoxy group cross-linking agent; the modified aramid fiber
polymer is obtained by carrying out
polymerization reaction on 1, 4-phenylenediamine-2-
sulfonic acid and 2, 6-
dipicolinic acid. The hydrophilic property of the
polymer is improved by the
pyridine ring and
sulfonic acid introduced into the modified aramid polymer, the prepared water-based
slurry is more environment-friendly, the reaction of the multi-
epoxy group cross-linking agent and the
polyvinyl alcohol of the PE / PVA composite diaphragm under the heating condition is promoted through the sulfonic group, a cross-linked network is formed, and the
binding force of the
coating and the base membrane is enhanced.