Space-confinement and chemisorption co-involved in encapsulation of sulfur for lithium – sulfur batteries with exceptional cycling stability

The practical applications of lithium–sulfur (Li–S) batteries have been impeded by short cycling life and low sulfur utilization, resulting from the dissolution of intermediate lithium polysulfides into electrolytes and the large volume variation during cycling. This study presents a dual-confinement strategy to efficiently entrap lithium polysulfides and alleviate large volume variation by using N-doped tube-in-tube structured carbon tubes anchored on a 3D scaffold of graphene foam through the synergistic effect of spatial restriction and chemical interaction. This unique carbon hybrid structure provides sufficient empty space to confine sulfur with high loading, accommodate large volume changes during lithiation and de-lithiation, and facilitate better immobilization of polysulfides as demonstrated by first-principles calculations. Therefore, enhanced capacities, ultralong-cycling stability, and improved rate capability even with a high sulfur loading (∼5.6 mg cm−2) could be achieved.MOE (Min. of Education, S’pore

Iron oxide-decorated carbon for supercapacitor anodes with ultrahigh energy density and outstanding cycling stability

10.1021/acsnano.5b00582ACS Nano955198-520

Water advancing and receding process as a liquid–vapor interface geometrical question

Existing wetting theories have difficulty accurately describing advancing/receding processes on micro-structured surfaces. A strategy is proposed to solve this problem by recognizing it as a liquid–vapor interface geometrical question. The wetting chip method is proposed to realize the microscopic observation of liquid–vapor interface variations. A wetting model based on the liquid–vapor interface shape (LVIS model) is established to describe the analytical relationships between the apparent contact angles, liquid–vapor interface radius, substrate geometry, and chemical nature of liquid. The LVIS model is divided into four typical time points and three transition stages, and its predictions agree with the experimental measurements. In contrast to traditional theories, the apparent contact angles in a quasi-equilibrium state should be separated into advancing and receding processes, and in this state, apparent contact angles vary with changes in the parameters of micro-pillar width and spacing. This strategy has the potential to accurately describe the wetting process on micro-structure surfaces

Multi-objective tracking for smart substation onsite surveillance based on YOLO Approach and AKCF

The onsite surveillance plays an important role in the smart substation since the smart substation is unattended. All the sites and operation staff should be supervised throughout the process since a series of risks exist on the working sites. KCF (Kernel Correlation Filter) is an effective method to track a moving object for safety surveillance. However, the occlusion and shape changes worsen the performance of KCF, especially on the occasion of multi-objective detection. This paper proposes a comprehensive method for improving the precision and robustness of detection. Firstly, all the moving objects are detected by the YOLO method. In the tracking part, an AKCF (Augmented Kernel Correlation Filter) is proposed for the heavily occluded object, and the Kalman Filter (KF) serves as a supplementary output. Moreover, in the target association section, based on priority matching and rematching based on motion estimation, a two-stage target association method is proposed. Test outcomes indicate that the proposed algorithm is accurate and robust for tracking workers’ trajectories and conducting surveillance