All-solid-state lithium batteries (ASSLBs) are receiving attention as a prospective next-generation secondary battery technology that can reduce the risk of commercial lithium-ion batteries by replacing flammable organic liquid electrolytes with non-flammable solid electrolytes. The practical application of ASSLBs requires developing robust solid electrolytes that possess ionic conductivity at room temperature on a par with that of organic liquids. These solid electrolytes must also be thermally and chemically stable, as well as compatible with electrode materials. Inorganic solid electrolytes, including oxide and sulfide-based compounds, are being studied as promising future candidates for ASSLBs due to their higher ionic conductivity and thermal stability than polymer electrolytes. Here, we present the challenges currently facing the development of oxide and sulfide-based solid electrolytes, as well as the research efforts underway aiming to resolve these challenges.
Thermal management is significant to maintain the reliability and durability of electronic devices. Heat can be dissipated using thermal interface materials (TIMs) comprised of thermally conductive polymers and fillers. Furthermore, it is important to enhance the thermal conductivity of TIMs through the formation of a heat transfer pathway. This paper reports a polymer composite containing vertically aligned electrochemically exfoliated graphite (EEG). We modify the EEG via edge selective oxidation to decorate the surface with iron oxides and enhance the dispersibility of EEG in polymer resin. During the heat treatment and curing process, a magnetic field is applied to the polymer composites to align the iron oxide decorated EEG. The resulting polymer composite containing 25 wt% of filler has a remarkable thermal conductivity of 1.10 W m− 1 K− 1 after magnetic orientation. These results demonstrate that TIM can be designed with a small amount of filler by magnetic alignment to form an efficient heat transfer pathway.
The purpose of this study was to explore the perceived benefits of telecollaboration for Korean pre-service teachers of English. This study connected Korean pre-service teachers to American pre-service teachers. In a one-to-one relationship, each pair exchanged their weekly writings about the assigned topics over six weeks and shared their ideas. To explore the perceived benefits that the Korean pre-service teachers of English perceived and provide a rich description, this study focused on the five Korean pre-service teachers’ thoughts reflected in their reflective papers, their writings in the Google Sites, and the final reflection paper. Data were analyzed based on a qualitative approach using the content analysis. The results showed that the Korean pre-service teachers perceived that the online interactions with the target language speakers promoted their intercultural and linguistic competences as well as some affective domains such as confidence and motivation levels. Building upon the findings, this study provides significant pedagogical implications for instructional practices for the educators and researchers.