Analysis of cycled 1 Ah Li-TiS₂ cells

摘要

The use of rechargeable lithium batteries is presently restrictedbecause of their limited cycle life and safety issues. To understand thecauses responsible for these limitations, 1 Ah Li-TiS₂ cellswere tested and studied by nondestructive and destructive methods beforeand after cycling. The nondestructive methods included microcalorimetryand AC impedance spectroscopy. Cycled cells showed higher heat outputafter cycling. Cells were disassembled and the components were analyzedfor their physical and chemical properties. The following changes wereobserved in the cell components with cycling: electrolyte consumption,lithium electrode swelling and disintegration, and separator dry out. Nosignificant disintegration or swelling of the cathode was observed withcycling. Lithium dendrites were seen on the anode and cathode separatorsof the cells that failed due to shorts. The results of these studiesindicated that capacity loss observed on cycling is mainly due toelectrolyte degradation/consumption