Exploration of Ultra-High Voltage Cathodes for Rechargeable Batteries

2021年的研究重点是探索具有更高工作电压和容量的高压电活性材料。其中一个研究方向是研究混合多阴离子体系（VO）2SO4PO4的插锂性能。我们期望氧、硫酸盐和磷酸盐阴离子的掺入为碱离子（Li/Na）插入提供稳定的框架，并具有优越的循环性能。事实上，我们可以获得不错的电化学性能。然而，所提出的体系的结构解显示它是相的混合物，不能解释其电化学性能，从而使研究在这一点上模棱两可。另一个研究方向是Na-Fe-S-O季硫酸盐体系的相变。本文研究了各种Na-Fe-S-O及其水合相随反应温度的密切关系。此外，我们还广泛研究了亚稳相Na2Fe2(SO4)2体系的稳定性、灵敏度和良好的电化学活性。这项提议的工作即将完成，我将按照所有这些结果发表在期刊上。

The research in 2021 fy focussed on exploring high voltage electro-active materials with increased operating voltages and capacities. One direction of research dwelled on study of mixed polyanionic system (VO)2SO4PO4 for their lithium insertion performances. We expected the incorporation of oxy, sulphate and phosphate anions to render stable framework for alkali ion (Li/Na) insertion with a superior cycling performance. Indeed, we could achieve decent electrochemical performance. However, the structural solutions of the proposed system revealed it to be mixture of phases and could not account for its electrochemical performance, thus making the research ambiguous at this point. Another direction focussed on phase transformations in Na-Fe-S-O quaternary sulphate systems. Here we studied intimate relationship between various Na-Fe-S-O and their hydrated phase with reaction temperature. Also, we studied extensively a metastable phase Na2Fe2(SO4)2 system for its stability, sensitivity, and decent electrochemical activities. This proposed work is near completion, and I am complying all these results for journal publication.