Phyllosilicates, whose frameworks are composed of alternating layers of corner-sharing SiO4 tetrahedra and edge sharing MO4(OH)2 metal layers, show promise as new materials for lithium ion batteries and exhibit unique magnetism because of their compositional tunability. Specifically, within this structure (supporting figure 1) there are 5 unique sites that can be altered to tune the properties: The tetrahedral (T) site, the trans-coordinated octahedral site (Ot) in yellow the cis-coordinated octahedral site (Oc) in red, the interlayer species (I), and hydroxyl site (H) which may be replaced with a fluorine or dehydroxylated. As a result this material can be modified to include multiple active metals. Thereby producing the opportunity to for both exchange between sites and a route to tailor properties by systematically altering the composition. Through hydrothermal synthesis we have been successful in preparing new phyllosilicates-type [Ni3]{Si(2-x)Alx}O5(OH)4, [Ni(3-x)Fex]{Si(2-x)Alx}O5(OH)4, [Ni(3-x)Cox]{Si2}O5(OH)4, and [Co(3-x)Mgx]{Si2}O5(OH)4 x= 0, 0.1, 0.2, 0.25, 0.3, 0.4 and 0.5. This family of compounds have shown promising electrochemical activity as well as unique magnetism in the iron and cobalt-containing phases. Phase purity has been determined by laboratory XRD and their composition confirmed by ICP-OES. Through both neutron pair distribution function analysis and Mossbauer spectroscopy studies we have determined the site occupancy of both the pure and mixed phase phyllosilicates allowing us to understand the relationship between structure and function in these compounds. This understanding has made it possible for us to then rationally design and synthesize multifunctional materials that can be optimized for use as green catalysts, environmentally friendly lithium ion battery electrodes, solid electrolytes, and psuedocapacitors.

Properties and design of multifunctional phyllosilicates

253rd National Meeting (2017)

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