POROUS ALUMINUM NITRIDE PART FABRICATION TO SUPPORT ADVANCED BATTERY DEVELOPMENT

ADVANCED BATTERIES BASED ON LITHIUM METAL SULFIDE CELL TECHNOLOGY ARE UNDER CONSIDERATION FOR APPLICATIONS SUCH AS THE ELECTRIC VEHICLE,PRIMARILY DUE TO THEIR HIGH ENERGY DENSITY CAPABILITIES. HOWEVER, CURRENTLY AVAILABLE MATERIALS LIMIT THE RELIABILITY OF THIS BATTERY TECHNOLOGY FOR LONG-TERM USE. IN PARTICULAR, THE CONTAINMENT OF THE ELECTROLYTE BY AN INERT SEPARATOR MATERIAL IS A DESIGN-LIMITING ISSUE. THE TYPICAL SEPARATOR FABRICATION METHOD, INVOLVING PRESSED POWDER COMBINATIONS, LEADS TO FRAGILE COMPONENTS THAT MAY SHIFT DURING USE, ALTERING THE ELECTRICAL RESPONSE OF THE CELL. IN EXTREME CASES, THE ENTIRE CELL MAY BE SHORTED. THE DEVELOPMENT OF A RIGID, POROUS SEPARATOR IS PLANNED IN THIS PROJECT IN ORDER TO ALLEVIATE THIS RELIABILITY ISSUE. ALUMINUM NITRIDE (AIN), A CANDIDATE MATERIAL FOR THE SEPARATOR COMPONENT, WILL BE FABRICATED INTO RIGID, POROUS PLATES USING AN EXISTING AQUEOUS-BASED ROLL FABRICATION METHOD AND SPECIALIZED SINTERING TECHNOLOGY. PHASE I SHOULD RESULT IN A SUITABLY POROUS, STRONG TILE THAT CAN BE IMPREGNATED WITH ELECTROLYTE AND INSERTED INTO THE BATTERY CELL AS AN INTEGRAL UNIT. TILES WITH INCREASED POROSITY WILL BE DEVELOPED, BASED ON TECHNOLOGY PREVIOUSLY USED TO MAKE TILES FOR REFRACTORY APPLICATIONS. THE TILE SEPARATOR CONCEPT IS EXPECTED TO GREATLY IMPROVE THE RELIABILITY OF THE ENTIRE CELL, AND IS ALSO EXPECTED TO IMPROVE THE COMMERCIAL VIABILITY OF THE CELL BY FACILITATING A REDUCTION IN CELL SIZE AND WEIGHT, AND BY IMPROVING THE ABILITY TO MASS MANUFACUTURE CELLS INEXPENSIVELY.