Magnesium-based batteries possess potential advantages over their lithium counterparts. However, reversible Mg chemistry requires a thermodynamically stable electrolyte at low potential, which is usually achieved with corrosive components and at the expense of stability against oxidation. In lithium-ion batteries the conflict between the cathodic and anodic stabilities of the electrolytes is resolved by forming an anode interphase that shields the electrolyte from being reduced. This strategy cannot be applied to Mg batteries because divalent Mg cannot penetrate such interphases. Here, we engineer an artificial Mg-conductive interphase on the Mg anode surface, which successfully decouples the anodic and cathodic requirements for electrolytes and demonstrate highly reversible Mg chemistry in oxidation-resistant electrolytes. The artificial interphase enables the reversible cycling of a Mg/VO full-cell in the water-containing, carbonate-based electrolyte. This approach provides a new avenue not only for Mg but also for other multivalent-cation batteries facing the same problems, taking a step towards their use in energy-storage applications.

Metal halide perovskite semiconductors possess outstanding characteristics for optoelectronic applications including but not limited to photovoltaics. Low-dimensional and nanostructured motifs impart added functionality which can be exploited further. Moreover, wider cation composition tunability and tunable surface ligand properties of colloidal quantum dot (QD) perovskites now enable unprecedented device architectures which differ from thin-film perovskites fabricated from solvated molecular precursors. Here, using layer-by-layer deposition of perovskite QDs, we demonstrate solar cells with abrupt compositional changes throughout the perovskite film. We utilize this ability to abruptly control composition to create an internal heterojunction that facilitates charge separation at the internal interface leading to improved photocarrier harvesting. We show how the photovoltaic performance depends upon the heterojunction position, as well as the composition of each component, and we describe an architecture that greatly improves the performance of perovskite QD photovoltaics.

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The purpose of this article is to discuss some concerns with the Game Performance Assessment Instrument (GPAI). This review of the GPAI includes five perceived problems with the GPAI scoring and coding system: (1) calculation of individual and overall game performance indices, (2) use of game involvement versus game performance index to analyze game performance, (3) observer reliability, (4) nonlinearity, and (5) usefulness of action. In this article, we suggest a reexamination of the GPAI scoring and coding system that will lead to more efficient use of this game performance instrument. Some of the suggested modifications can be implemented quickly, whereas others need further research.

We outline the evolution of a computerised systematic observation tool and describe the process for establishing the validity and reliability of this new instrument. The Coach Analysis and Interventions System (CAIS) has 23 primary behaviours related to physical behaviour, feedback/reinforcement, instruction, verbal/non-verbal, questioning and management. The instrument also analyses secondary coach behaviour related to performance states, recipient, timing, content and questioning/silence. The CAIS is a multi-dimensional and multi-level mechanism able to provide detailed and contextualised data about specific coaching behaviours occurring in complex and nuanced coaching interventions and environments that can be applied to both practice sessions and competition.