Nickel-rich layered oxide cathodes promise ultrahigh energy density but is plagued by the mechanical failure of the secondary particle upon (de)lithiation. Existing approaches for alleviating the structural degradation could retard pulverization, yet fail to tune the stress distribution and root out the formation of cracks. Herein, we report a unique strategy to uniformize the stress distribution in secondary particle via Kirkendall effect to stabilize the core region during electrochemical cycling. Exotic metal/metalloid oxides (such as Al₂O₃ or SiO₂) is introduced as the heterogeneous nucleation seeds for the preferential growth of the precursor. The calcination treatment afterwards generates a dopant-rich interior structure with central Kirkendall void, due to the different diffusivity between the exotic element and nickel atom. The resulting cathode material exhibits superior structural and electrochemical reversibility, thus contributing to a high specific energy density (based on cathode) of 660 Wh kg⁻¹ after 500 cycles with a retention rate of 86%. This study suggests that uniformizing stress distribution represents a promising pathway to tackle the structural instability facing nickel-rich layered oxide cathodes.

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CycloMedia is a Dutch company specialized in the large-scale and systematic visualization of environments based on 360° panoramic photographs. The images are captured from public roads at street level, using a car to carry a panoramic camera system. High resolution spherical panoramas are geometrically correct and thus allow a user to perform photogrammetric 3D measurements and use imagery for 3D modelling and texture mapping. Drawing 3D point cloud (or rather pixel cloud) is a relatively new approach to use panoramic images. Currently there is no completely steady and consummate method to reconstruct digital building models from point clouds, thus this project aims to propose an innovative and practical framework of building reconstruction in particular. The developed method uses segmentation by region growing based on normals and curvature, constructing topology between segments by Voronoi partitioning, shape simplification by segmented least squares and principal component analysis methods. The method proves to have good results while tested on Lidar point clouds, however with some modifications is also applicable to pixel clouds obtained from panoramic imagery.@en

Addressing the mismatch between the intermittent solar irradiation and the time-varying load demand, the optimal energy management principle with its corresponding control scheme for stand-alone PV-H2 system is investigated to achieve high energy efficiency. Based on the proposed optimal energy management strategy, a systematical system sizing method is developed for determining the minimum capacity of the system components. Therefore the system hardware cost can be well assessed using the developed system sizing method. Case studies are carried out to verify the effectiveness of the proposed energy management strategy and system sizing method. Simulation results show that the investigation in this article provides a good straightforward solution to the pre-design and operation of stand-alone PV-H2 systems. Keywords: Photovoltaic hydrogen; Stand-alone power system; Energy management; System sizing@en