Enhancement of Low Temperature Superionic Conductivity by Suppression of Li Site Ordering in Li7Si2-xGexS7I.

Ge4+ substitution into the recently discovered superionic conductor Li7Si2S7I is demonstrated by synthesis of Li7Si2-xGexS7I, where x ≤ 1.2. The anion packing and tetrahedral silicon location of Li7Si2S7I are retained upon substitution. Single crystal X-ray diffraction shows that substitution of larger Ge4+ for Si4+ expands the unit cell volume and further increases Li+ site disorder, such that Li7Si0.88Ge1.12S7I has one Li+ site more (sixteen in total) than Li7Si2S7I. The ionic conductivity of Li7Si0.8Ge1.2S7I (x = 1.2) at 303 K is 1.02(3) × 10-2 S cm-1 with low activation energies for Li+ transport demonstrated over a wide temperature range by AC impedance and 7Li NMR spectroscopy. All sixteen Li+ sites remain occupied to temperatures as low as 30 K in Li7Si0.88Ge1.12S7I as a result of the structural expansion. This differs from Li7Si2S7I, where the partial Li+ site ordering observed below room temperature reduces the ionic conductivity. The suppression of Li+ site depopulation by Ge4+ substitution retains the high mobility to temperatures as low as 200 K, yielding low temperature performance comparable with state-of-the-art Li ion conducting materials.

Superionic lithium transport via multiple coordination environments defined by two-anion packing.

Fast cation transport in solids underpins energy storage. Materials design has focused on structures that can define transport pathways with minimal cation coordination change, restricting attention to a small part of chemical space. Motivated by the greater structural diversity of binary intermetallics than that of the metallic elements, we used two anions to build a pathway for three-dimensional superionic lithium ion conductivity that exploits multiple cation coordination environments. Li7Si2S7I is a pure lithium ion conductor created by an ordering of sulphide and iodide that combines elements of hexagonal and cubic close-packing analogously to the structure of NiZr. The resulting diverse network of lithium positions with distinct geometries and anion coordination chemistries affords low barriers to transport, opening a large structural space for high cation conductivity.

Developing Innovative Virtual Reality Simulations to Increase Health Care Providers' Understanding of Social Determinants of Health.

INTRODUCTION: Health care providers (HCPs) who work primarily with Medicaid patients must be competent in identifying and addressing social determinants of health (SDH). A curricular gap exists between promoting an understanding of SDH and teaching HCPs how to recognize and increase empathy to manage them. The project aim was to develop two virtual reality simulations (VRSs) as innovative methods to teach HCPs to identify and manage SDH. A secondary aim was to decrease unconscious bias and increase empathy by experiencing SDH from their patients' perspective. METHODS: Scripts for two VRSs were created by two HCP educators and clinicians. Scripts were evaluated by experts using an index of content validity (CVI). An advisory panel critiqued the scripts for appropriateness for VRSs, adequacy of evidence-based practice, and use of VRS equipment and software. The panel participated in a focus group and completed a final evaluation. The VRSs then were pilot tested with five HCPs who assessed content and utility and participated in interviews. This led to iterative improvements. Qualitative data were analyzed using a content analysis approach. RESULTS: The VRS scripts demonstrated adequate content-related validity evidence with CVI scores of 0.81 and 0.75. The expert panel found the VRS easy to use, useful as an educational tool, while promoting empathy for patients. Overall, participants were satisfied with using the VRS as an educational experience. DISCUSSION: Through VRS technology, this project addresses a curricular gap in HCP training on SDH. VRS can be a useful tool to increase HCPs' understanding of SDH and, potentially, their empathy for patients.