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The acoustic black hole (ABH) structures have been shown to have great potential for energy harvesting. Within an ABH, the bending wave velocity decreases rapidly and the phase accumulates, resulting in localised energy accumulation. It is very significant that the energy can be harvested and power can be supplied for microelectronic devices. How to improve energy harvesting capacity is a problem that needs to be solved. Previous research on energy harvesting capacity of straight beams and flat plates with ABH has yielded a wealth of results. However, in practical engineering, curved beams are also commonly found. Given the differences in structure, it is of practical significance to study the influence factors on harvesting capacity of the piezoelectric vibration energy harvesting system covered on curved beam with acoustic black hole. First, the vibration characteristics of curved beam with ABH are analysed by the finite element method and localised energy accumulation is observed. Then, energy harvesting capacity is studied by means of the electromechanical coupling model in FEA; it has been found that energy harvesting capacity is lower in high frequency. The reason of this problem is analysed and solved by dividing the size of the piezoelectric sheet in an array layout. Based on this, the influence of array layout of piezoelectric cells on the energy harvesting capacity of the system is focused on. In addition, the influence of resistance value, material property, and curvature of curved beam on the energy harvesting capacity is analysed. Some meaningful results are obtained. These results provide the guidance to the design and optimisation for an energy harvesting system covered on curved beam with ABH. [ABSTRACT FROM AUTHOR]

WS 2 is an attractive anode in alkali metal ion batteries (AMIBs) due to its 2D-layered structure and high theoretical capacity. However, the shuttle effect of sulfur and the spontaneous growth of W nanoparticles are key issues that limit the alkali-ion accommodation ability. Now, it is still a great challenge to achieve in situ control of the microstructure evolution paths in enclosed batteries for extending the cycling reversibility/lifespan. Herein, the phase conversion paths of both film- and powder-type WS 2 anodes are investigated in lithium-ion batteries. It is found that the reversible conversion mechanism is beneficial for alleviating the shuttle effect through strong W-Li x S y bonding. Also, once the size of the phase-converted W/WS 2 redox pair exceeds ∼10 nm inside the anode layer, the Li + storage ability will severely decay due to uncontrollable W precipitation. To maintain high reversibility, amorphous Al 2 O 3 is introduced upon pristine WS 2 . After initializing the battery test, the particle size of the W/WS 2 redox pair is in situ modulated within the range of ∼3-5 nm because of the refinement effect of gradually pulverized Al 2 O 3 . Thus, the decay suppression effect lasting over 750-1400 cycles is obtained with enhanced W ↔ WS 2 conversion efficiency and good capacity retention. This is expected to promote the optimization of Mo-group sulfides/selenides/tellurides toward AMIBs.