Söllinger Daniela, Karl Michael, Redhammer Günther J, Schoiber Jürgen, Werner Valérie, Zickler Gregor A, Pokrant Simone
Chemistry and Physics of Materials, University of Salzburg, 5020, Salzburg, Austria.
ChemSusChem. 2021 Feb 18;14(4):1112-1121. doi: 10.1002/cssc.202002757. Epub 2021 Jan 5.
Nanostructured H V O is a promising high-capacity cathode material, suitable not only for Li but also for Na+, Mg , and Zn insertion. However, the full theoretical capacity for Li insertion has not been demonstrated experimentally so far. In addition, improvement of cycling stability is desirable. Modifications like substitution or prelithiation are possibilities to enhance the electrochemical performance of electrode materials. Here, for the first time, the substitution of vanadium sites in H V O with molybdenum was achieved while preserving the nanostructure by combining a soft chemical synthesis approach with a hydrothermal process. The obtained Mo-substituted vanadate nanofibers were further modified by prelithiation. While pristine H V O showed an initial capacity of 223 mAh g and a retention of 79 % over 30 cycles, combining Mo substitution and prelithiation led to a superior initial capacity of 312 mAh g and a capacity retention of 94 % after 30 cycles.
纳米结构的HVO是一种很有前景的高容量阴极材料，不仅适用于锂，也适用于钠、镁和锌的嵌入。然而，到目前为止，锂嵌入的完整理论容量尚未通过实验得到证实。此外，提高循环稳定性是很有必要的。诸如取代或预锂化等改性方法是提高电极材料电化学性能的可能途径。在此，首次通过将软化学合成方法与水热过程相结合，在保持纳米结构的同时实现了用钼取代HVO中的钒位点。所获得的钼取代钒酸盐纳米纤维通过预锂化进一步改性。原始的HVO初始容量为223 mAh g，在30次循环后保持率为79%，而结合钼取代和预锂化则导致了312 mAh g的优异初始容量以及30次循环后94%的容量保持率。
