Vanadium flow batteries(VFBs)are considered ideal for grid-sc ale,long-duration energy storage applications owing to their decoupled output power and storage capacity,high safety,efficiency,and long cycle life.However...Vanadium flow batteries(VFBs)are considered ideal for grid-sc ale,long-duration energy storage applications owing to their decoupled output power and storage capacity,high safety,efficiency,and long cycle life.However,the widespread adoption of VFB s is hindered by the use of expensive Nafion membranes.Herein,we report a soft template-induced method to develop a porous polyvinylidene fluoride(PVDF)membrane for VFB applications.By incorporating water-soluble and flexible polyethylene glycol(PEG 400)as a soft template,we induced the aggregation of hydrophilic sulfonated poly(ether ether ketone),resulting in phase separation from the hydrophobic PVDF polymer during membrane formation.This process led to the creation of a porous PVDF membrane with controllable morphologies determined by the polyethylene glycol content in the cast solution.The optimized porous PVDF membrane enabled a stable VFB performance for 200 cycles at a current density of 80 mA/cm^(2),and the VFB exhibited a Coulombic efficiency of 95.2%and a voltage efficiency of 87.8%.These findings provide valuable insights for the development of highly stable membranes for VFB applications.展开更多
The influence of swelling and stripping acidity on the mass transfer coefficient based on water phase and the inner diameters of membranes were studied with P507-HCl-Sm as working system in the two different kinds of ...The influence of swelling and stripping acidity on the mass transfer coefficient based on water phase and the inner diameters of membranes were studied with P507-HCl-Sm as working system in the two different kinds of hollow fiber membranes. Effects of extractant concentration, H+ concentration in aqueous phase and Sm3+ concentration on extraction rate were discussed and the corresponding reaction series were obtained. According to the investigations on the interfacial kinetics, the reaction kinetics equation and reaction rate constant were obtained.展开更多
Porous polyvinylidene fluoride（PVDF）membranes blended with LiCl are prepared through the phase inversion method to obtain a good support layer for air dehumidification.The hydrophilicity of the resulting membrane is...Porous polyvinylidene fluoride（PVDF）membranes blended with LiCl are prepared through the phase inversion method to obtain a good support layer for air dehumidification.The hydrophilicity of the resulting membrane is evaluated by water contact angle measurements and vapor adsorption tests.The moisture permeation performance of the membrane is measured by permeation tests in terms of total mass transfer coefficients and moisture permeability rates.It is found that water contact angles and water vapor adsorption capacities increase with the increasing LiCl content in the casting solution.As the LiCl content increases,the total mass transfer coefficient increases slightly at a low LiCl content（below 2.5%）and then improves greatly at a high LiCl content（above 2.5%）,whereas the moisture permeation rate increases.The results demonstrate that LiCl can remarkably improve the hydrophilicity of PVDF membranes,and then greatly enhance moisture permeation performance.展开更多
基金financially supported by Open Fund of Material Corrosion and Protection Key Laboratory of Sichuan Province of China(No.2020CL09)Hunan Key Laboratory of Applied Environmental Photocatalysis(No.2214503)。
文摘Vanadium flow batteries(VFBs)are considered ideal for grid-sc ale,long-duration energy storage applications owing to their decoupled output power and storage capacity,high safety,efficiency,and long cycle life.However,the widespread adoption of VFB s is hindered by the use of expensive Nafion membranes.Herein,we report a soft template-induced method to develop a porous polyvinylidene fluoride(PVDF)membrane for VFB applications.By incorporating water-soluble and flexible polyethylene glycol(PEG 400)as a soft template,we induced the aggregation of hydrophilic sulfonated poly(ether ether ketone),resulting in phase separation from the hydrophobic PVDF polymer during membrane formation.This process led to the creation of a porous PVDF membrane with controllable morphologies determined by the polyethylene glycol content in the cast solution.The optimized porous PVDF membrane enabled a stable VFB performance for 200 cycles at a current density of 80 mA/cm^(2),and the VFB exhibited a Coulombic efficiency of 95.2%and a voltage efficiency of 87.8%.These findings provide valuable insights for the development of highly stable membranes for VFB applications.
文摘The influence of swelling and stripping acidity on the mass transfer coefficient based on water phase and the inner diameters of membranes were studied with P507-HCl-Sm as working system in the two different kinds of hollow fiber membranes. Effects of extractant concentration, H+ concentration in aqueous phase and Sm3+ concentration on extraction rate were discussed and the corresponding reaction series were obtained. According to the investigations on the interfacial kinetics, the reaction kinetics equation and reaction rate constant were obtained.
基金The National Natural Science Foundation of China(No.50676034)the National High Technology Research and Development Program of China(863 Program)(No.2008AA05Z206)
文摘Porous polyvinylidene fluoride（PVDF）membranes blended with LiCl are prepared through the phase inversion method to obtain a good support layer for air dehumidification.The hydrophilicity of the resulting membrane is evaluated by water contact angle measurements and vapor adsorption tests.The moisture permeation performance of the membrane is measured by permeation tests in terms of total mass transfer coefficients and moisture permeability rates.It is found that water contact angles and water vapor adsorption capacities increase with the increasing LiCl content in the casting solution.As the LiCl content increases,the total mass transfer coefficient increases slightly at a low LiCl content（below 2.5%）and then improves greatly at a high LiCl content（above 2.5%）,whereas the moisture permeation rate increases.The results demonstrate that LiCl can remarkably improve the hydrophilicity of PVDF membranes,and then greatly enhance moisture permeation performance.
