IGF::OT::IGF 1.0 INTRODUCTION/BACKGROUND NATIONAL AERONAUTICS AND SPACE ADMINISTRATION S GAME CHANGING TECHNOLOGY DEVELOPMENT PROGRAM IS DEVELOPING BATTERY TECHNOLOGY TO SUBSTANTIALLY IMPROVE THE PERFORMANCE OF SECONDARY (RECHARGEABLE) LITHIUM-ION CELLS TO MEET THE ENERGY STORAGE REQUIREMENTS OF HUMAN MISSIONS. FUTURE NASA MISSIONS REQUIRE ADVANCED BATTERIES THAT SAFELY PROVIDE SUBSTANTIALLY HIGHER SPECIFIC ENERGY AND ENERGY DENSITY THAN IS CURRENTLY AVAILABLE. THUS BEYOND LITHIUM-ION BATTERY CHEMISTRIES ARE PURSUED TO MEET THE HIGHER SPECIFIC ENERGY, PERFORMANCE AND SAFETY GOALS FOR FORESEEABLE HUMAN MISSIONS. THE PROPOSAL OF GARNET ELECTROLYTE BASED SAFE, LITHIUM-SULFUR ENERGY STORAGE BY UNIVERSITY OF MARYLAND TEAM HAS BEEN AWARDED IN THE PHASE I UNDER CATEGORY TWO: VERY HIGH SPECIFIC ENERGY DEVICE TO PROVE THE FEASIBILITY OF PROPOSED WORK TO MEET THE NASA ENERGY AND SAFETY REQUIREMENTS. 2.0 SCOPE OF WORK THE CONTACTORS WILL BUILD ALL SOLID-STATE LI-S BATTERIES (POUCH CELLS OR COIN CELLS) USING TRIPLE-LAYER GARNET ELECTROLYTES FILLED WITH CONFORMAL CARBON. THE TARGETED ENERGY DENSITY OF THE CELLS IS 600 WH/KG WITH CYCLING LIFE OF 200 WITH A 90% DISCHARGE DEPTH AT ROOM TEMPERATURE. THE CONTRACTOR WILL PROVIDE THE SPECIFICATIONS OF THE ANODE, CATHODE AND SOLID ELECTROLYTE CHEMISTRY IN THE CONSTRUCTION OF THE CELLS. THE CONTRACTOR WILL PROVIDE DATA AND ANALYSIS FOR ADDRESSING THE OPERATIONAL SAFETY ISSUES. TWO CELLS WITH THE IDENTICAL DESIGN FOR THE ABOVE TEST CELLS SHALL BE PROVIDED FOR INDEPENDENT PERFORMANCE CHARACTERIZATION TESTING AT NASA GRC. THE CONTRACTOR WILL ALSO PROVIDE A DESIGN FOR BATTERY STACKS TO MEET THE TOTAL ENERGY REQUIREMENTS OF NASA GAME CHANGING DEVELOPMENT PROGRAM. THE PROJECT IS CURRENTLY ESTIMATED AT A TECHNOLOGY READINESS LEVEL OF 2 (AS DEFINED IN NASA NPR 7123.1B) AND WILL END AT A TRL 3 AT THE END OF THE PHASE I EFFORT. DURING PHASE I, THE CONTRACTOR SHALL DEMONSTRATE THE FEASIBILITY OF FURTHER ADVANCING THE TRL DURING SUBSEQUENT PHASES OF DEVELOPMENT. 3.0 TASKS THERE ARE FIVE TASKS FOR THE PROPOSED RESEARCH TASK 1. DEVELOPMENT OF DENSE-POROUS TRIPLE LAYER GARNET ELECTROLYTE STRUCTURE A POROUS-DENSE-POROUS TRIPLE LAYER WILL BE FABRICATED FROM LI-ION CONDUCTING GARNETS BY LAMINATING THE POROUS-DENSE-POROUS TRIPLE LAYER AND CO-SINTERING, WHERE THE OUTSIDE POROUS LAYERS ARE USED AS THE LI-ION CONDUCTING PHASE IN THE LI ANODE AND S CATHODE. 1.1 FABRICATION AND CHARACTERIZATIONS OF DENSE LAYER THE DENSITY WILL BE OPTIMIZED BY PARTICLE SIZE AND SINTERING TEMPERATURE AND CHARACTERIZED BY SEM. 1.2 FABRICATION AND CHARACTERIZATIONS OF POROUS LAYER THE POROSITY WILL BE OPTIMIZED BY PMMA PORE FORMER CONTENT AND SINTERING TEMPERATURE AND CHARACTERIZED USING BET AND SEM. 1.3 FABRICATION OF TRIPLE LAYER AND POTENTIAL SCALABLE STRATEGY THE TRIPLE LAYER WILL BE FABRICATED BY LAMINATION AND SINTERING OF THE THREE LAYERS. MICROSTRUCTURE WILL BE CHARACTERIZED BY BET AND SEM AND CONDUCTIVITY MEASURED BY EIS. TASK 2. INTEGRATE SULFUR (S) CATHODE INTO POROUS GARNET AS CATHODE ONE OUTER POROUS LI-GARNET LAYER WILL BE FILLED WITH CARBON NANOFIBERS (CNF) AND S TO FORM THE CATHODE. 2.1 POROUS, CONFORMAL NANOCARBON COATING IN THE PORES OF CATHODE SIDE CNF WILL BE DEPOSITED IN THE POROUS LI-GARNET LAYER USING MICROWAVE SYNTHESIS METHOD OR USING CNF SOLUTION. 2.2 VACUUM BASED FILLING OF SULFUR CATHODE S WILL BE INFILTRATED INTO CNF COATED POROUS LI-GARNET LAYER BY S GAS VACUUM INFUSION AT 600 C. THE CONDUCTIVITY OF S-CNF FILLED POROUS LI-GARNET WILL BE EVALUATED USING EIS. TASK 3. LI-INFILTRATION INTO POROUS GARNET AS ANODE ONE OUTER POROUS LI-GARNET LAYER WILL BE FILLED WITH CNF AND LI TO FORM THE ANODE. 3.1 INFILTRATION OF LI IN POROUS GARNET LI WILL BE INFILTRATED INTO CNF FILLED POROUS LI-GARNET LAYER BY PRE-HEATING IN AR GAS AND TO REMOVE THE MOISTURE, AND THEN INFILTRATE LIQUID LI INTO THE CNF FILLED PORES. 3.2 CHARACTERIZATIONS OF INTERFACIAL IMPED