Molten Salt Electrolytes for High-Temperature Lithium Cells

摘要

The high-temperature lithium cells under study at the Argonne National Laboratory (ANL) utilize either Li-Al, Li-Si, or Li-Al-Si negative electrodes; FeS, FeS sub 2 , or (Ni, Fe)S sub 2 positive electrodes; and a molten salt electrolyte. The cells operate in the temperature range of 400-475/degree/C, depending on the electrolyte composition and choice of positive electrode. At present, Gould Inc. is fabricating and testing prismatic Li-Al-SiFeS cells, and ANL is evaluating both cylindrical and prismatic designs for the Li-AlFeS sub 2 cell. In the past, the bulk of the research and development effort on the lithiumsulfide cells emphasized the Li-AlFeS over the Li-AlFeS sub 2 system because of the poor capacity retention of the Li-AlFeS sub 2 system and the cost of the current collector materials associated with the FeS sub 2 electrode. However, because the Li-AlFeS sub 2 system has the potential of yielding cells with higher specific energy and power than those obtainable with the Li-AlFeS system, it is now receiving greater attention. In the paper, we will review the importance of the molten salt electrolyte in the performance of the Li-AlFeS sub 2 system and the recent breakthroughs in capacity retention achieved with this system. (ERA citation 13:033707)