Exploring high-capacity electrode materials is critical for the development of K-ion batteries.In this work,we report a layered-structured tungsten selenide(WSe2)anode,which not only delivers an ultrahigh volumetric c...Exploring high-capacity electrode materials is critical for the development of K-ion batteries.In this work,we report a layered-structured tungsten selenide(WSe2)anode,which not only delivers an ultrahigh volumetric capacity of 1772.8 Ah/L(or 188.4 mAh/g)at a current density of 5 mA/g but also exhibits good rate capability(72 mAh/g at 200 mA/g)and cycling stability(83.14%capacity retention over 100 cycles at 100 mA/g).We have also revealed the underlying reaction mechanism through ex situ X-ray powder diffraction.Furthermore,proof-of-concept full-cell batteries comprising of WSe2 anodes and Prussian Blue cathodes are capable of delivering an energy density of 135.2 Wh/kgcathode+anode.This work highlights the potential of WSe2 as a promising high-volumetric-capacity anode material for rechargeable potassium-ion batteries.展开更多
In order to enhance photocatalytic water splitting rates with Pt/TiO2 powder, sufficient agitation of the biphasic medium is required to switch surficial reactions to volumetric reactions. Additionally, agitation is c...In order to enhance photocatalytic water splitting rates with Pt/TiO2 powder, sufficient agitation of the biphasic medium is required to switch surficial reactions to volumetric reactions. Additionally, agitation is conducive to higher diffusion rates of the generated hydrogen and co-produced oxygen, hindering their ability to re-couple to water on Pt loaded to TiO2 powder. In order to create agitation without consuming any electricity, a novel technique utilizing Rayleigh convection was applied, and its ability to enhance photocatalytic water splitting rates was evaluated. Higher Rayleigh convective flow rates resulted in higher photocatalytic water splitting rates. Utilization of Rayleigh convection approximately doubled the photocatalytic water splitting rates, despite relatively low convective flow velocities (obtained through simple thermo-hydrodynamic simulations). The rate enhancement achieved through Rayleigh convection is a result of its ability to disperse the ultrafine Pt/TiO2 particles throughout the whole medium, leading to volumetric reactions.展开更多
A two-stage micro-impinging stream reactor(TS-MISR) that combined a first pre-mixing stage with a second micro-impinging stream reacting stage for continuous multi-component reacting systems has been built from commer...A two-stage micro-impinging stream reactor(TS-MISR) that combined a first pre-mixing stage with a second micro-impinging stream reacting stage for continuous multi-component reacting systems has been built from commercial T-junctions and steel micro-capillaries. Both of operating parameters and reactor configurations,such as jet Reynolds number(Rej), volumetric flow ratio(R), the first-stage junction angle(φ), the connecting capillary length(Lc) and connecting capillary diameter(dc), had significant effects on the micromixing efficiency of the reactor. Such effects were investigated for both of the two stage structures, respectively, by experimental and CFD methods and were optimized for the best micromixing performance. Intensified micromixing among at least three reacting components can be achieved in a continuous mode by using TS-MISR; therefore, it is expected that the TS-MISR will produce products of higher quality with more uniform and stable element distribution.展开更多
基金the National Natural Science Foundation of China (Nos. 21771180, 21971239)Natural Science Foundation of Fujian Province (No. 2020J06032)。
文摘Exploring high-capacity electrode materials is critical for the development of K-ion batteries.In this work,we report a layered-structured tungsten selenide(WSe2)anode,which not only delivers an ultrahigh volumetric capacity of 1772.8 Ah/L(or 188.4 mAh/g)at a current density of 5 mA/g but also exhibits good rate capability(72 mAh/g at 200 mA/g)and cycling stability(83.14%capacity retention over 100 cycles at 100 mA/g).We have also revealed the underlying reaction mechanism through ex situ X-ray powder diffraction.Furthermore,proof-of-concept full-cell batteries comprising of WSe2 anodes and Prussian Blue cathodes are capable of delivering an energy density of 135.2 Wh/kgcathode+anode.This work highlights the potential of WSe2 as a promising high-volumetric-capacity anode material for rechargeable potassium-ion batteries.
文摘In order to enhance photocatalytic water splitting rates with Pt/TiO2 powder, sufficient agitation of the biphasic medium is required to switch surficial reactions to volumetric reactions. Additionally, agitation is conducive to higher diffusion rates of the generated hydrogen and co-produced oxygen, hindering their ability to re-couple to water on Pt loaded to TiO2 powder. In order to create agitation without consuming any electricity, a novel technique utilizing Rayleigh convection was applied, and its ability to enhance photocatalytic water splitting rates was evaluated. Higher Rayleigh convective flow rates resulted in higher photocatalytic water splitting rates. Utilization of Rayleigh convection approximately doubled the photocatalytic water splitting rates, despite relatively low convective flow velocities (obtained through simple thermo-hydrodynamic simulations). The rate enhancement achieved through Rayleigh convection is a result of its ability to disperse the ultrafine Pt/TiO2 particles throughout the whole medium, leading to volumetric reactions.
基金Supported by the National Natural Science Foundation of China(Nos.21376015,21576012 and 91334206)
文摘A two-stage micro-impinging stream reactor(TS-MISR) that combined a first pre-mixing stage with a second micro-impinging stream reacting stage for continuous multi-component reacting systems has been built from commercial T-junctions and steel micro-capillaries. Both of operating parameters and reactor configurations,such as jet Reynolds number(Rej), volumetric flow ratio(R), the first-stage junction angle(φ), the connecting capillary length(Lc) and connecting capillary diameter(dc), had significant effects on the micromixing efficiency of the reactor. Such effects were investigated for both of the two stage structures, respectively, by experimental and CFD methods and were optimized for the best micromixing performance. Intensified micromixing among at least three reacting components can be achieved in a continuous mode by using TS-MISR; therefore, it is expected that the TS-MISR will produce products of higher quality with more uniform and stable element distribution.
