REDOX FLOW CELL DIAPHRAGM

• Main Authors: KAGIYAMA YASUHIRO, YAMAMOTO TAKAHISA, KANEDA JUNJI
• Format: Patent
• Language: English
• Published: 08.02.1988
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

PURPOSE:To obtain a cell diaphragm with low metal ion permeation, high potential efficiency and Coulomb efficiency by forming an alkyl group thin layer combined with chain aliphatic compounds having carbon numbers of 6-30 on the surface at least on one side of a cation exchange membrane. CONSTITUTION:A paste mixture, obtained by mixing 2 parts of benzoyl peroxide with 90 parts of styrene, 10 parts of 55%-purity divinyl benzene, 20 parts of dioctyl phthalate and 100 parts of polyvinyl chloride powder, is applied to a polyvinyl chloride cloth. Then, after deaerating, both sides thereof are covered with cellophane and a polymer film of about 0.11 mm thick is formed by heat polymerization at 110 deg.C for 4 hrs. The film is immersed in a mixture of 98%-conc. sulfuric acid/90% or more-purity chlorosulfonic acid (1:1) for 40 min at 40 deg.C, to introduce sulfonyl chloride groups and sulfonic acid groups. Then after air-drying and immersing in tetradecyl epoxide, caustic aqueous solution and 1N-hydrochloric acid, a desired diaphragm is prepared.