Utilization of non-lithium-ion batteries in nextgeneration renewable energy storage is hindered by the lack of appropriate electrode materials with desired electrochemical performance. Motivated by low peeling-off energy (Jing et al. Nano Lett. 2017, 17(3), 1833−1838, an experimentally available two-dimensional material, nominated as GeP 3 , is investigated as the anode for non-lithium-ion batteries (Na + , K + , Ca 2+ , Mg 2+ , Al 3+ ) based on density functional theory calculations. The electrochemical properties, i.e., ion intercalation mechanism, diffusion behavior, and theoretical capacities of different metal ions in GeP 3 , are systematically investigated. A semiconductor-to-metal transition and improved conductivity are observed due to ions intercalation in the GeP 3 electrode. Even though the charge storage mechanism of Na and Ca ions is quite different, the GeP 3 monolayer has exhibited a high theoretical capacity of 1295.42 mAh g −1 for both Na + and Ca 2+ ions. Furthermore, collective Na ions transport at the phase boundary indicates that the sodiated GeP 3 electrode favors well-distributed phase formation instead of separation or clustering at the nanoscale, which is beneficial in avoiding the thermal runaway issues induced by dendrite formation. Moreover, the shallow and steady intercalation/deintercalation resistance of the Na ion at the dilute limit and phase boundary in GeP 3 suggests excellent rate performance and high cyclic stability. These results provide a steady path toward further development and utilization of two-dimensional GeP 3 as an anode in non-lithium-ion batteries.

No abstract

No abstract

A new lower tungsten divertor has been developed and installed in the EAST superconducting tokamak to replace the previous graphite divertor with power handling capability increasing from <2 MW m−2 to ∼10 MW m−2, aiming at achieving long-pulse H-mode operations in a full metal wall environment with the steady-state divertor heat flux of ∼10 MW m−2. A new divertor concept, ‘corner slot’ (CS) divertor, has been employed. By using the ‘corner effect’, a strongly dissipative divertor with the local buildup of high neutral pressure near the corner can be achieved, so that stable detachment can be maintained across the entire outer target plate with a relatively lower impurity seeding rate, at a separatrix density compatible with advanced steady-state core scenarios. These are essential for achieving efficient current drive with low-hybrid waves, a low core impurity concentration and thus a low loop voltage for fully non-inductive long-pulse operations. Compared with the highly closed small-angle-slot divertor in DIII-D, the new divertor in EAST exhibits the following merits: (1) a much simpler geometry with integral cassette body structure, combining vertical and horizontal target plates, which are more suitable for actively water-cooled W/Cu plasma facing components, facilitating installation precision control for minimizing surface misalignment, achieving high engineering reliability and lowering the capital cost as well; (2) it has much greater flexibility in magnetic configurations, allowing for the position of the outer strike point on either vertical or horizontal target plates to accommodate a relatively wide triangularity range, δ l = 0.4–0.6, thus enabling to explore various advanced scenarios. A water-cooled copper in-vessel coil has been installed under the dome. Five supersonic molecular beam injection systems have been mounted in the divertor to achieve faster and more precise feedback control of the gas injection rate. Furthermore, this new divertor allows for double null divertor operation and slowly sweeping the outer strike point across the horizontal and vertical target plates to spread the heat flux for long-pulse operations. Preliminary experimental results demonstrate the ‘corner effect’ and are in good agreement with simulations using SOLPS-ITER code including drifts. The EAST new divertor provides a test-bed for the closed divertor concept to achieve steady-state detachment operation at high power. Next step, a more closed divertor, ‘sharp-cornered slot’ divertor, building upon the current CS divertor concept, has been proposed as a candidate for the EAST upper divertor upgrade.

No abstract

No abstract

No abstract

In this Article, ZnO nanofibers were prepared by electrospinning. The as-prepared ZnO electrospun fibers were treated with plasma. The morphology, structure, and element content of the ZnO nanofibers greatly changed after treatment with different plasmas. The test results indicated that the acetone-sensing performance was remarkably improved for oxygen-plasma-assisted ZnO nanofibers. Furthermore, the density function theory (DFT) calculation results revealed that the acetone adsorption energy of ZnO nanofibers treated with oxygen plasma was 2 times greater than that of untreated ZnO nanofibers, and the electrons transferred between ZnO nanofibers and acetone molecules produced a more remarkable change in electronic structure for the oxygen-plasma-treated ZnO nanofibers. Our work demonstrates that the oxygen plasma treatment method can help improve the acetone-sensing performance of ZnO nanofibers.