Effects of Discharge/Charge Cycles on Inner Structures of Laminated Cells of Lithium Air Batteries By X-Ray CT, SEM/EDS and FIB-SEM/EDS

Abstract

Lithium-air battery (LAB) is considered to be one of the most promising energy storage devices because of its large theoretical energy density. However, low cyclability caused by battery degradation prevents its practical use.Here we employed X-ray CT to monitor the structural development of laminated cell of lithium air batteries without dismantling the cells. The results are compared with those of SEM/EDS and FIB-SEM/EDS analyses, which were carried out after dismantling the cells.Figure 1 shows XCT images of cross section and slice of laminated cell of lithium air battery after several discharge/charge cycles. Each component is well resolved. Figure 2 shows XCT images of cross section of laminated cell of lithium air battery (a) as prepared, and after (b) one, and (c) ten discharge/charge cycles. It is clear lithium became porous even just after one cycle. The porous layer became much thicker after 10 cycles. For detailed understanding of the structure of the porous layer of lithium, the cells were dismantled and were subject to SEM/EDS and FIB-SEM/EDS analyses. Degradation of lithium layer was much less significant if the anode and cathode were separated by solid electrolyte (Ohara). Detailed results and advantages of XCT will discussed. Figure 1