Based on Darcy＇s Law and the Helmholta-Smoluchowski equation, an imbibition velocity formula for the water phase with an electric field was deduced, showing that the imbibition velocity with an electric field is to v...Based on Darcy＇s Law and the Helmholta-Smoluchowski equation, an imbibition velocity formula for the water phase with an electric field was deduced, showing that the imbibition velocity with an electric field is to various extents not only related to the rock permeability and characteristic length, the fluid viscosity, the oil-water interface tension and the gravity of the imbibing brine, but also to the fluid dielectric permittivity, zeta potential, applied electric field direction, and strength. Imbibition experiments with electric fields that are different in direction and strength were conducted, showing that application of a positive electric field enhances the imbibition velocity and increases the imbibition recovery ratio, while application of a negative electric field reduces the imbibition velocity and decreases the imbibition recovery ratio. The imbibition recovery ratio with a positive electric field increases with the strength of the electric field, and the imbibition recovery ratio with a negative electric field is lower than that without an electric field.展开更多
Selenium(Se)is a promising cathode material for lithium batteries due to its high volumetric energy density(2528 Wh·L^(-1)).However,its practical application is restricted by rapid capacity fading resulting from ...Selenium(Se)is a promising cathode material for lithium batteries due to its high volumetric energy density(2528 Wh·L^(-1)).However,its practical application is restricted by rapid capacity fading resulting from the shuttle effect and slow reaction kinetics.Herein,a N/Co co-doped three-dimensional porous carbon(Co-NC)is prepared and used as Se host for lithium-selenium batteries(LSeBs).Co-NC displays a high specific surface area of1201 m^(2)·g^(-1)which benefits from N and Co doping.The N and Co not only enhance the electrical conductivity of porous carbon but also possess an adsorption effect on polyselenide.Thus,Se/Co-NC electrode exhibits excellent cycling performance(a stable specific capacity of 480 mAh·g^(-1)after 200 cycles at 1.0C with a much lowcapacity decay of 0.028%per cycle)and outstanding rate performance(a high specific capacity of 414 mAh·g^(-1)at5.0C).This work inspires highly stable Se cathode design for LSeBs.展开更多
基金supported by the National Key Basic Research Development Program of China (Grant No. 2002CCA00700)
文摘Based on Darcy＇s Law and the Helmholta-Smoluchowski equation, an imbibition velocity formula for the water phase with an electric field was deduced, showing that the imbibition velocity with an electric field is to various extents not only related to the rock permeability and characteristic length, the fluid viscosity, the oil-water interface tension and the gravity of the imbibing brine, but also to the fluid dielectric permittivity, zeta potential, applied electric field direction, and strength. Imbibition experiments with electric fields that are different in direction and strength were conducted, showing that application of a positive electric field enhances the imbibition velocity and increases the imbibition recovery ratio, while application of a negative electric field reduces the imbibition velocity and decreases the imbibition recovery ratio. The imbibition recovery ratio with a positive electric field increases with the strength of the electric field, and the imbibition recovery ratio with a negative electric field is lower than that without an electric field.
基金financially supported by the National Key Research and Development Project(No.2018YFE0124800)the Research Project of Education Department of Jiangxi Province(No.GJJ190310)Natural Science Foundation of Jiangxi Province(No.20212BAB204006)。
文摘Selenium(Se)is a promising cathode material for lithium batteries due to its high volumetric energy density(2528 Wh·L^(-1)).However,its practical application is restricted by rapid capacity fading resulting from the shuttle effect and slow reaction kinetics.Herein,a N/Co co-doped three-dimensional porous carbon(Co-NC)is prepared and used as Se host for lithium-selenium batteries(LSeBs).Co-NC displays a high specific surface area of1201 m^(2)·g^(-1)which benefits from N and Co doping.The N and Co not only enhance the electrical conductivity of porous carbon but also possess an adsorption effect on polyselenide.Thus,Se/Co-NC electrode exhibits excellent cycling performance(a stable specific capacity of 480 mAh·g^(-1)after 200 cycles at 1.0C with a much lowcapacity decay of 0.028%per cycle)and outstanding rate performance(a high specific capacity of 414 mAh·g^(-1)at5.0C).This work inspires highly stable Se cathode design for LSeBs.
