Chemical and Electrochemical Characterization of Hot-Pressed Li6PS5Cl Solid State Electrolyte: Operating Pressure-Invariant High Ionic Conductivity.

Sulfide solid state electrolytes (SSE) are among the most promising materials in the effort to replace liquid electrolytes, largely due to their comparable ionic conductivities. Among the sulfide SSEs, Argyrodites (Li6PS5X, X=Cl, Br, I) further stand out due to their high theoretical ionic conductivity (~1×10-2 S cm-1) and interfacial stability against reactive metal anodes such as lithium. Generally, solid state electrolyte pellets are pressed from powder feedstock at room temperature, however, pellets fabricated by cold pressing consistently result in low bulk density and high porosity, facilitating interfacial degradation reactions and allowing dendrites to propagate through the pores and grain boundaries. Here, we demonstrate the mechanical and electrochemical implications of hot-pressing standalone LPSCl SSE pellets with near-theoretical ionic conductivity, superior cycling performance, and enhanced mechanical stability. X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and x-ray diffraction spectroscopy (XRD) analysis reveal no chemical changes to the Argyrodite surface after hot pressing up to 250 °C. Moreover, we use electrochemical impedance spectroscopy (EIS) to understand mechanical stability of Argyrodite SSE pellets as a function of externally applied pressure, demonstrating for the first time pressed standalone Argyrodite pellets with near-theoretical conductivities at external pressures below 14 MPa.

Reference Electrode Reveals Insights on Sodium Metal/Solid Electrolyte Interface Cycling and Voiding Behaviors at High Current Densities and Areal Capacities.

Plating and stripping processes at solid metal electrode/solid electrolyte interfaces are of great significance for high-energy, solid-state batteries. Here, we introduce a Na metal reference electrode to a symmetric Na metal/sodium ß″ alumina/Na metal cell and study both cycling and unidirectional protocols with a focus on high current density and areal capacity. For example, in a current ramp test at 5 mAh cm-2 we find a shift from stable to unstable interfacial polarization during stripping at ≳3 mA cm-2, and at 7.5 mA cm-2 we measure 100s of mV of voltage magnitude rise at the stripping electrode and 10s of mV of voltage changes at the plating electrode. In unidirectional testing (i.e., passing current in a single direction until cell failure), at 1.2 mA cm-2 we find only ∼40% of the initial Na foil could be transferred through the solid electrolyte and again observe 100s of mV (and larger) voltage magnitude rise at the stripping electrode and 10s of mV of voltage change at the plating electrode. This test also shows that the 100s of mV of interfacial polarization can be sustained for hours (at 1.2 mA cm-2) to tens of hours (in a test at 0.3 mA cm-2). Hence, across several test protocols we find a Na metal reference electrode provides quantitative insights on electrochemical interfacial behavior that are not revealed in two-electrode testing. We also built a two-dimensional model of our three-electrode symmetric cell to quantify the link between the measured interfacial potentials in our testing and changes in electrochemically active interfacial contact and find that 100s of mV of interfacial potential rise indicates loss of electrochemically active contact area of >80%. Our work provides a promising approach to clarify the coupled interfacial electrochemical and contact mechanics processes at solid metal electrode/solid electrolyte interfaces.

Rapid E-Learning for professional development in school-based diabetes management.

The number of school aged youth in the United States requiring assistance in the management of diabetes has reached over 200,000. School nurses are often charged with the training of personnel and provision of assistance to children with this chronic disease. The need for quick, efficient, and accessible training methods is necessary to ensure school nurses have the most current information necessary to perform their duties. The purpose of this study was to assess the effectiveness of a rapid e-learning module for school nurse professional development in school-based diabetes management. A sample (N = 1977, n = 1127) of school nurses was asked to complete a module addressing current and/or changing information on diabetes management, the training of staff charged with assisting students, and the associated pre- and post-tests for the module. A total of 678 nurses completed the pre-test, while 449 nurses completed the post-test. T-test results for independent samples indicated a significant increase (p < 0.001) in knowledge at post-test. Results support the contention that e-modules are a convenient and effective way to provide professional development opportunities and improve nurses' knowledge.

Exploring Public Health and Nursing Students' Perceptions of Each Other's Professional Roles.

Public health education specialists and nurses often work interprofessionally in the public health setting. Using a mixed-methods design, this exploratory study evaluated the effect of an online interprofessional case study activity on nursing and public health education students' perceptions of each other's professional role. For the public health experimental group only, a statistically significant change (p < .05) was found in their perceptions of the professional roles of nurses including large changes in six specific domains. Recommendations for implementing interprofessional education programs include more emphasis on education about professional scopes of practice and roles/responsibilities of the health professions.

Rural elementary students', parents', and teachers' perceptions of bullying.

OBJECTIVE: To examine the prevalence and correlates of bullying in 7 rural elementary schools from students', parents', and teachers' perspectives. METHOD: Surveys were completed by 739 fourth, fifth, and sixth grade students, 367 parents, and 37 teachers. RESULTS: Students tended to report higher prevalence of bullying than did parents or teachers, and their reports were associated with aggression, attitudes toward violence, and perceptions of school safety. CONCLUSION: Bullying behavior is prevalent in rural elementary schools and is indicative of aggression and proviolence attitudes. Parents and teachers need to pay closer attention to bullying behavior among schoolchildren and to impart their knowledge to children in a comprehensive, coordinated manner.