Preparation for diaphragm for molten carbonate fuel battery

Abstract

The preparation of diaphragm includes three steps of compounding size, film preparation and hot pressing of diaphragm. The material includes alpha-LiAlO2, polyvinyl butyral, n-octyl phthalate, cod-fish oil as dispersant, silicon oil as defoaming agent and solvent being mixture of n-butanol with content not less than 80% and ethyl alcohol. The diaphragm thus prepared has homogeneous texture and thickness and high density and can be used to produce battery with good electrochemical property.

Description

technical field [0001] The invention provides a method for preparing an inorganic membrane, in particular a method for preparing a diaphragm for a molten carbonate fuel cell. Background technique [0002] The U.S. and Japan etc. began to use the hot rolling method to make molten carbonate fuel cell membranes in the eighties, and then changed to the tape casting method to make membranes until now (Japanese patent publication flat 2-186563, flat 1-130474, J.ElctroChem.Soc. , Vol 127, No: 8, P1663 (1980), J. ElectroChem. Soc., Vol 135, No: 1, P221 (1988)). Some of them use a single LiAlO 2 Coarse material, some use a certain thickness ratio (5-15% is fine material, particle size <1μ) γ-type LiAlO 2 The powder is fully ball milled into a slurry with polyvinyl butyral (PVB) binder, dioctyl phthalate plasticizer and toluene, xylene, acetone, methanol, chloroform and other single solvents. Scrape the slurry on a horizontal floor and let it dry to form a film in a container sa...

AI Technical Summary

Problems solved by technology

Therefore, the film-making formula has many defects, and it is difficult to produce a battery separator with small pore size and good thermomechanical properties.

[0004] (2) It has been proved by experiments that the artificial scraping film will bring air bubbles in the process of scraping the film, and the scraped film is not very uniform

[0005] (3) Scrape the film into a container saturated with organic solvent vapor, and gradually control the volatilization of the organic solvent, so that the film cannot be dried quickly, and the film will not dry for a long time. Due to the action of gravity, LiAlO 2 The powder is easy to settle, the lower layer has more coarse material and less organic matter; the upper layer has more fine material and more organic matter; the composition of the film is uneven, the room temperature and humidity change slightly, or the solvent volatilization is slightly out of control, and the film cracks, so the operation is troublesome. poor reliability