Transition-metal fluorosulfates are currently under intense investigation for their use as anodes in Li-ion batteries. The substitution of Zn into LiFeSO4F has been found to trigger a transition from the tavorite structure to two separate polymorphs which crystallize in the sillimanite and triplite structures (see picture). These new phases show Fe2+/Fe3+ redox potentials of 3.6 and 3.9 V versus Li, respectively.
No takes yet. Share an insight, caveat, or question.
Ati et al. (2011) studied this question.