NOVEL CONCEPTS FOR HYDROGEN-BROMINE BATTERY

AN INNOVATIVE APPROACH IS PROPOSED TO DRAMATICALLY IMPROVE THE HYDROGEN/BROMINE BATTERY AS A RECHARGEABLE POWER SUPPLY. THE PRESENT FUEL CELL-ELECTROLYZER SYSTEM USES 48 PERCENT HBR WITH NAFION AS A SOLID POLYMER ELECTROLYTE MEMBRANE. THE INTRINSIC CHARACTERISTICS OF THIS NAFION BASED SYSTEM ARE: (1) A CONSTANTLY CHANGING NERNST POTENTIALASSOCIATED WITH CHANGING HBR CONCENTRATIONS AND (2) THE NEEDFOR AN INORDINATE AMOUNT OF WATER WHICH IS ESSENTIALLY INERTFOR POWER APPLICATION. THE RESEARCHERS PROPOSE TO OVERCOME THESE DISADVANTAGES BY EMPLOYING ANION SELECTIVE MEMBRANES. TWO SPECIFIC PROBLEMS TO BE ADDRESSED ARE (1) IDENTIFICATIONOF A STABLE BROMIDE ION CONDUCTING MEMBRANE AND (2) THE STABILITY OF THE CATALYST SYSTEM. PRELIMINARY RESULTS IN THIS LABORATORY SHOW THAT FLUOROPOLYMER BASED MEMBRANES WEREUNATTACKED BY PURE BROMINE AND AQUEOUS SOLUTION OF BROMINE DURING ONE DAY AND EIGHT WEEK EXPOSURES, RESPECTIVELY. IT WAS ALSO CONFIRMED THAT THIS MEMBRANE WAS IMPERVIOUS TO GASEOUS HYDROGEN AND BROMINE VAPORS AT 60 DEGREES CENTIGRADE. A CELL WITH CARBON BLACK AT THE BROMINE ELECTRODE AND PLATINUM BASED CATALYST AT THE HYDROGEN ELECTRODE GAVE EXCELLENT OPEN CIRCUIT POTENTIAL. ABILITY TO OPERATE ON ANHYDROUS, GASEOUS, AND LIQUID BROMINE WITH RELATIVELY LOW MEMBRANE RESISTANCE WAS OBSERVED IN SHORT TIME TESTS. IN THE PROPOSED RESEARCH, ELECTROCHEM, INC., WILL ESTABLISH A TECHNOLOGICAL BASE FOR THE DESIGN OF EFFICIENT, RELIABLE, AND LONG LIVED SECONDARY BATTERIES. SPECIFICALLY, THEY WILL INVESTIGATE LONG TERM STABILITY OF MEMBRANE AND CATALYST SYSTEMS, IDENTIFY CRITICAL NEEDS IN THE MEMBRANE AND CATALYSIS RESEARCH, AND ESTABLISH A STRONG BASIS FOR PHASE II RESEARCH. FURTHERMORE, THIS UNIQUE RESEARCH IS EXPECTED TO STIMULATE DEVELOPMENT IN MEMBRANE TECHNOLOGY AND CHEMICAL AND THERMODYNAMIC SCIENCES.