Ordering determination of Li2CoSiO4 polymorphs by first-principles calculations

First-principles computations coupled with simulated Xrd are used to investigate Li2CoSiO4 polymorphism with symmetries Pmn21, Pbn21 and P21/n. We find that complex polymorphic structures can be characterized by transition metal ordering, which presents a fingerprint in the Xrd spectra. Li/Co mixing order is determined for βII-Pmn21 polymorph, which provides a structural template to achieve highly stable intercalation cycling. We illustrate that the material properties of Li2CoSiO4 polymorphs depend on cationic orderings, and we offer insights on materials preparation under high pressure and heat. This may help realize new silicate materials using the strategy of solid solutions.