RESUMO
The development of conversion-typed anodes with ultrafast charging and large energy storage is quite challenging due to the sluggish ions/electrons transfer kinetics in bulk materials and fracture of the active materials. Herein, the design of porous carbon nanofibers/SnS2 composite (SnS2 @N-HPCNFs) for high-rate energy storage, where the ultrathin SnS2 nanosheets are nanoconfined in N-doped carbon nanofibers with tunable void spaces, is reported. The highly interconnected carbon nanofibers in three-dimensional (3D) architecture provide a fast electron transfer pathway and alleviate the volume expansion of SnS2 , while their hierarchical porous structure facilitates rapid ion diffusion. Specifically, the anode delivers a remarkable specific capacity of 1935.50 mAh g-1 at 0.1 C and excellent rate capability up to 30 C with a specific capacity of 289.60 mAh g-1 . Meanwhile, at a high rate of 20 C, the electrode displays a high capacity retention of 84% after 3000 cycles and a long cycle life of 10 000 cycles. This work provides a deep insight into the construction of electrodes with high ionic/electronic conductivity for fast-charging energy storage devices.
RESUMO
PVDF/ZnO/CuS photocatalysts with ZnO/CuS heterojunctions were synthesized via electrospinning, hydrothermal, and ion-exchange techniques. As matrix materials, electrospun PVDF nanofibers are easy to be recycled and reused. ZnO nanorods anchored on PVDF nanofiber with high specific surface area provide abundant active reaction sites for photocatalysis. While the loaded CuS nanoparticles as a photosensitizer compensate the low quantum efficiency of ZnO and improve the visible-light photocatalytic efficiency. As a result, the PVDF/ZnO/CuS composited photocatalyst exhibits outstanding photocatalytic performance in exposure to UV and visible light owing to the suppressed recombination of electron-hole pairs and widened visible light absorption range. The kinetic constants of PVDF/ZnO/CuS nanocomposites under UV irradiation (9.01 × 10-3 min-1) and visible light (6.53 × 10-3 min-1) irradiation were 3.66 and 2.53 times higher than that of PVDF/ZnO (2.46 × 10-3 min-1 & 2.58 × 10-3 min-1), respectively. Furthermore, PVDF/ZnO/CuS nanocomposites demonstrate excellent robustness in terms of recycling and reuse, which is advantageous in practical applications.
RESUMO
Current lithium-ion battery technology is approaching the theoretical energy density limitation, which is challenged by the increasing requirements of ever-growing energy storage market of electric vehicles, hybrid electric vehicles, and portable electronic devices. Although great progresses are made on tailoring the electrode materials from methodology to mechanism to meet the practical demands, sluggish mass transport, and charge transfer dynamics are the main bottlenecks when increasing the areal/volumetric loading multiple times to commercial level. Thus, this review presents the state-of-the-art developments on rational design of the commercialization-driven electrodes for lithium batteries. First, the basic guidance and challenges (such as electrode mechanical instability, sluggish charge diffusion, deteriorated performance, and safety concerns) on constructing the industry-required high mass loading electrodes toward commercialization are discussed. Second, the corresponding design strategies on cathode/anode electrode materials with high mass loading are proposed to overcome these challenges without compromising energy density and cycling durability, including electrode architecture, integrated configuration, interface engineering, mechanical compression, and Li metal protection. Finally, the future trends and perspectives on commercialization-driven electrodes are offered. These design principles and potential strategies are also promising to be applied in other energy storage and conversion systems, such as supercapacitors, and other metal-ion batteries.
RESUMO
Bioinspired superhydrophobic surfaces have attracted great interest due to their special functions and wide applications. However, it is still a big challenge to construct a durable superhydrophobic coating for large-scale applications due to its easy destruction by the mechanochemical attack. In this mini-review, we present the state-of-the-art developments in the rational design of mechanochemical durable and self-healing superhydrophobic surfaces. First, the mechanically durable superhydrophobic surfaces are constructed to endure mechanical damage by adjusting the surface morphology and increasing the binding force between the substrates and the modified materials. Second, chemical damages also have been taken into consideration to develop chemically robust superhydrophobic surfaces, such as chemical etching, ultraviolet (UV)-light irradiation, and bioerosion, etc. Third, endowing superhydrophobic coatings with self-healing function can effectively improve the durability and prolong the lifespan of the coatings by releasing low-surface-energy agents or regenerating topographic structures. Finally, the challenges and future perspectives in developing super durable bioinspired superhydrophobic surfaces by structure design and chemistry control are discussed. The innovative points provided in this mini-review will provide deep fundamental insight for prolonging the lifetime of the superhydrophobic surfaces and enable their practical applications in the near future.
