BATTERIES THAT OPERATE AT LOW TEMPERATURES ARE CRITICAL FOR THE SUCCESS OF FUTURE SPACE EXPLORATION MISSIONS. THIS RESEARCH PROJECT IS FOCUSED ON DEVELOPING LITHIUM METAL ANODES FOR USE AT TEMPERATURES AS LOW AS -80 DEGREES C WHICH WILL ENABLE THE CREATION OF RECHARGEABLE BATTERIES WITH HIGHER ENERGY DENSITY AND SPECIFIC ENERGY SUITABLE FOR USE IN SPACE APPLICATIONS. CONVENTIONAL LI-ION BATTERIES CANNOT BE USED EFFICIENTLY AT TEMPERATURES BELOW ~ -20 TO -30 DEGREES C DUE TO KINETICS LIMITATIONS ARISING FROM DIFFUSION WITHIN ELECTRODE MATERIALS AND INTERFACE RESISTANCE. WHILE RECENT BREAKTHROUGHS HAVE YIELDED ELECTROLYTES WITH SUFFICIENT IONIC CONDUCTIVITY AT LOW TEMPERATURES THE DEVELOPMENT OF ELECTRODE MATERIALS SUITABLE FOR OPERATION AT TEMPERATURES AS LOW AS -80 DEGREES C HAS LAGGED BEHIND. THE SPECIFIC OBJECTIVE OF THIS PROPOSED RESEARCH IS TO UNDERSTAND AND CONTROL THE MORPHOLOGICAL TRANSFORMATIONS INTERFACIAL EVOLUTION AND ELECTROCHEMICAL KINETICS OF HIGH-CAPACITY LI METAL ELECTRODES OPERATING AT LOW TEMPERATURES IN RECHARGEABLE BATTERIES. THE LI METAL ELECTRODE IS THE FOCUS OF THIS STUDY FOR TWO REASONS. FIRST THIS MATERIAL IS HYPOTHESIZED TO EXHIBIT FASTER KINETICS THAN INTERCALATION-TYPE LI-ION BATTERY MATERIALS AT LOW TEMPERATURES DUE TO FUNDAMENTAL DIFFERENCES IN THE ELECTROCHEMICAL REACTION MECHANISMS AT PLAY. SECOND LI METAL ELECTRODES HAVE ~10 TIMES GREATER THEORETICAL SPECIFIC CAPACITY COMPARED TO CONVENTIONAL GRAPHITE ANODES. THIS PROJECT WILL INVOLVE THE USE OF OPERANDO AND CRYO-BASED CHARACTERIZATION TECHNIQUES TO DETERMINE HOW LOW TEMPERATURES INFLUENCE THE EVOLUTION OF THE MICROSCALE MORPHOLOGY OF LI METAL AND THE NANOSCALE STRUCTURE OF THE SOLID-ELECTROLYTEINTERPHASE (SEI) DURING CHARGE/DISCHARGE. THIS INFORMATION IS CRITICAL FOR INTERPRETING THE ELECTROCHEMICAL BEHAVIOR AND KINETICS OF LI ELECTRODES. THIS KNOWLEDGE WILL THEN GUIDE THE ENGINEERING OF LI INTERFACES THROUGH THE DEPOSITION OF PROTECTIVE COATINGS TO MAXIMIZE CHARGE TRANSFER KINETICS WHILE MAINTAINING MORPHOLOGICAL STABILITY FOR IMPROVED CYCLABILITY AT LOW TEMPERATURES. THE END RESULT WILL BE THE DEVELOPMENT OF HIGH-CAPACITY TAILORED LI METAL ELECTRODES WITH FAST KINETICS AND IMPROVED ELECTROCHEMICAL CYCLING STABILITY AT LOW TEMPERATURES. THE RESULTS AND OUTCOMES OF THIS PROJECT WILL ESTABLISH THE SCIENTIFIC AND TECHNOLOGICAL FOUNDATION FOR THE DEVELOPMENT OF LIGHTER AND MORE COMPACT RECHARGEABLE BATTERIES THAT WILL ENABLE ENHANCED FUNCTIONALITY IN A VARIETY OF SPACE-BORNE VEHICLES.