HYDROGEN EVOLUTION REACTION MECHANISM AND ITS INHIBITION AT IRON ANODES FOR ADVANCED BATTERIES

INCREASING URBAN POLLUTION HAS LED TO A FAVORABLE REASSESSMENT OF ELECTRIC VEHICLES. EXISTING COMMERCIAL SECONDARY BATTERIES, NAMELY, LEAD-ACID AND NICKEL-CADMIUM, HAVE MAJOR DRAWBACKS IMPEDING COMMERCIALIZATION. THESE INCLUDE LOW ENERGY DENSITY, AND POOR CYCLE LIFE (HENCE, HIGH LIFE CYCLE COSTS) FOR LEAD ACID. THE DEVELOPMMENT OF A COST-EFFECTIVE, MISSION-EFFECTIVE ELECTRIC VEHICLE IS AGAIN BECOMING A PRIORITY FOR URBAN PLANNERS AND AUTOMOBILE MANUFACTURERS. THE ONLY AVAILABLE STORAGE BATTERY THAT CAN OFFER AN ADQUATE LIFE CYCLE COST WITH AN ENERGY DENSITY THAT IS UP TO 75 PERCENT HIGHER THAN LEAD-ACID IS NICKEL-ION. HOWEVER, BECAUSE OF THE EASE OF HYDROGEN EVOLUTION AT ION ANODES, THIS BATTERY SUFFERS FROM POOR CHARGING EFFICIENCY AND A HIG SELF-DISCHARGE RATE WHICH DEGRADE ENERGY EFFICIENCY. RESEARCHERS ARE DETERMINING THE HYDROGEN EVOLUTION REACTION MECHANISM FOR IRON ELECTRODES IN CONCENTRATED ALKALINE SOLUTIONS, TYPICAL OF NICKEL-IRON BATTERY ELECTROLYTES. BASED ON THE IDENTIFIED REACTION MECHANISM, A RANGE OF ELECTROLYTE ADDITIVES IS BEING SELECTED AND EVALUATED TO DETERMINE THEIR EFFECTIVENESS FOR INHIBITING THE ENREGY-WASTING HYDROGEN EVOLUTION REACTION ON IRON ANODES. THE RESEARCH EFFORT IS DIRECTED TOWARD DETERMINING THE BEST-PERFORMING AND MOST STABLE INHIBITORS, BOTH UNDER CHARG AND DISCHARGE CONDITIONS, SO AS TO IMPROVE THE CHARGE ACCEPTANCE AND LOWER THE SELF-DISCHARGE RATE OF ALKALINE ANODES. THIS GIVES RISE TO THE MOST COST-EFFECTIVE SOLUTION IN RENDERING THE NICKEL-IRON BATTERY ENERGY-EFFICIENT AND USER-SAFE AS AN ELECTRIC VEHICLE ENERGY STORAGE SYSTEM.