Tracking Displacement Reactions in CuxV2O5 Cathodes by in-situ TEM

In order to meet the growing demand of the rapidly-miniaturized electronics and high-power mobile devices (i.e. hybrid electric vehicles), a lot of new electrode materials are studied to replace the traditional LiCoO2 (cathode) and graphite (anode). Cu-V-O compounds with high capacity (~250-500 mAh.g -1 ) have emerged as one of the most promising cathode materials for next-generation lithium ion batteries. However, for these applications one of the issues is the poor cycle life, namely capacity decay with cycling. In these compounds, the reduction/oxidation of Cu between 2+ and 0, which results in local formation/consuming of metallic Cu nanostructures, leads to significant changes in both crystal structure and morphology [1]. Whether the structure/morphology can be fully reversed or not during cycling significantly influences its electrochemical performance, e.g., capacity, cycling stability, therefore it’s crucial to understand these structural and morphological evolutions in Cu-V-O cathode material during cycling.