Capacity loss, which happens in formation cycles, is one of the problems of Li-ion batteries. A part of the lithium originally stored in the cathode material is used for the passivation layer, that is formed on the graphite anode. The formation of the SEI contributes to lower battery energy density. With the prelithiation or by adding lithium to the cell, capacity loss could be compensated. The aim of this bachelor’s thesis is to investigate whether the lithium rich compound lithium manganese oxyfluoride (Li2MnO2F), which is obtained by mechanochemical synthesis, has the ability to prelithiate the cell in the formation cycle. To clearly show the prelithiation process, TiO2 was selected as a cathode material. Electrodes containing TiO2 and electrodes with TiO2 / Li2MnO2F mixture were prepared and then cycled versus metal lithium, graphite electrode and versus graphite with lithium. It was found that during galvanostatic cycling versus graphite anode all the lithium from the sacrificial compound Li2MnO2F was used for passivation. Because of that, cycling of TiO2, that is part of the cathode material does not continue. This hypothesis was verified by adding a small piece of lithium to the graphite electrode. Results from cycling of the cathode material (Li2MnO2F and TiO2) versus metal lithium and versus graphite were then compared. This way, it was shown that when using the sacrificial compound Li2MnO2F, lithium is used for passivation and afterwards, no lithium is left for cycling. Thus, it can be argued that Li2MnO2F does not contain enough lithium to prelithiate the cell. After cycling, electrodes were analysed with scanning electron microscopy (SEM). It was observed that, while cycling, cathode material (Li2MnO2F) does not degrade.
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