Alkaline water electrolysis(AWE)represents a promising approach for green hydrogen production,yet the development of high-performance separators with gas impermeability,high ion conductivity,and stability under alkali...Alkaline water electrolysis(AWE)represents a promising approach for green hydrogen production,yet the development of high-performance separators with gas impermeability,high ion conductivity,and stability under alkaline operating conditions has proven challenging.To address this challenge,we develop a pre-concentration regulated phase separation strategy for scalable fabrication of asymmetric hierarchical porous membranes(AHPMs)for AWE.The resulting AHPMs demonstrate a hierarchical structure composed of an ultrathin dense skin layer and highly interconnected porous support.Benefitting from the structural advantages,the AHPMs exhibit outstanding characteristics,including a high bubble point pressure up to 12.4 bar,extremely low area resistance of 0.03Ωcm^(2) in 30 wt%KOH at 80℃,and excellent hydrophilicity and long-term alkaline stability.When applied in AWE with commercial catalysts,the AHPMs achieved an impressive current density of 1.9 A cm^(-2) at 2.0 V in 30 wt%KOH and the anodic hydrogen contents(AHCs)below 0.5 vol.%at a low current density of 0.1 A cm^(-2),differential pressure of 2 bar,and temperature of 80℃.Moreover,AHPMs demonstrate exceptional stability over 2,400 h of continuous operation and maintain superior performance in a 1 Nm^(3) h^(-1) industrialscale electrolyzer stack.This work advances the development of efficient separators for highperformance AWE systems,contributing to the advancement of hydrogen technologies in sustainable energy applications.展开更多
The safety and performance of lithium-ion batteries(LIBs)largely depend on the structural design and performance characteristics of the separator.Commercial polyolefin separators suffer from problems such as poor ther...The safety and performance of lithium-ion batteries(LIBs)largely depend on the structural design and performance characteristics of the separator.Commercial polyolefin separators suffer from problems such as poor thermal stability,insufficient porosity,and inferior electrolyte wettability,which not only easily lead to battery safety issues but also significantly affect the ionic conductivity and energy density of the batteries.Herein,we have designed a facile,efficient and controllable methodology to develop a high-porosity poly(m-phenylene isophthalamide)(PMIA)separator with both excellent wettability and superior thermal resistance by a vapor-induced phase separation technique.Specifically,the PMIA separator undergoes a thermal shrinkage of less than 1%even after being treated at 200℃ for one hour,which greatly enhances the thermal safety of the battery.In addition,a continuous and interconnected high-porosity structure(porosity of 69%)is formed by utilizing a stable and controllable solvent exchange rate,thereby constructing abundant channels for the transportation of ions within the battery.Moreover,the amide groups in the PMIA molecular structure further confer the separator with excellent wettability,enabling it to possess outstanding electrolyte absorption capacity(electrolyte absorption rate of 270%).As a result,the Li||LFP full cell with PMIA separator exhibits excellent capacity and cycling stability,maintaining a reversible specific capacity of 105.6 mAh g^(-1)after 600 cycles at 5 C.And Li||NCM811 full cell with PMIA separator show no significant degradation(168.1 mAh g^(-1)at 0.5 C)after long-cycle at high temperature.These results indicate the potential of the PMIA separator for high thermal stability and high energy battery,and the scalability of this technology also provides new ideas and directions for the preparation of separators with superior comprehensive performance.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52273059 and 52473219)the Natural Science Foundation of Tianjin(Grant Nos.22JCYBJC01030 and 23JCYBJC00650)provided by Yantai Tayho Advanced Materials Group Co.,Ltd.
文摘Alkaline water electrolysis(AWE)represents a promising approach for green hydrogen production,yet the development of high-performance separators with gas impermeability,high ion conductivity,and stability under alkaline operating conditions has proven challenging.To address this challenge,we develop a pre-concentration regulated phase separation strategy for scalable fabrication of asymmetric hierarchical porous membranes(AHPMs)for AWE.The resulting AHPMs demonstrate a hierarchical structure composed of an ultrathin dense skin layer and highly interconnected porous support.Benefitting from the structural advantages,the AHPMs exhibit outstanding characteristics,including a high bubble point pressure up to 12.4 bar,extremely low area resistance of 0.03Ωcm^(2) in 30 wt%KOH at 80℃,and excellent hydrophilicity and long-term alkaline stability.When applied in AWE with commercial catalysts,the AHPMs achieved an impressive current density of 1.9 A cm^(-2) at 2.0 V in 30 wt%KOH and the anodic hydrogen contents(AHCs)below 0.5 vol.%at a low current density of 0.1 A cm^(-2),differential pressure of 2 bar,and temperature of 80℃.Moreover,AHPMs demonstrate exceptional stability over 2,400 h of continuous operation and maintain superior performance in a 1 Nm^(3) h^(-1) industrialscale electrolyzer stack.This work advances the development of efficient separators for highperformance AWE systems,contributing to the advancement of hydrogen technologies in sustainable energy applications.
基金supported by the National Natural Science Foundation of China(52273059,52403046)the Science and Technology Plans of Tianjin(22JCYBJC01030)+1 种基金the Tianjin Research Innovation Project for Postgraduate Students(2022BKY145)partially supported by financial contributions from Yantai Tayho Advanced Materials Co.,Ltd。
文摘The safety and performance of lithium-ion batteries(LIBs)largely depend on the structural design and performance characteristics of the separator.Commercial polyolefin separators suffer from problems such as poor thermal stability,insufficient porosity,and inferior electrolyte wettability,which not only easily lead to battery safety issues but also significantly affect the ionic conductivity and energy density of the batteries.Herein,we have designed a facile,efficient and controllable methodology to develop a high-porosity poly(m-phenylene isophthalamide)(PMIA)separator with both excellent wettability and superior thermal resistance by a vapor-induced phase separation technique.Specifically,the PMIA separator undergoes a thermal shrinkage of less than 1%even after being treated at 200℃ for one hour,which greatly enhances the thermal safety of the battery.In addition,a continuous and interconnected high-porosity structure(porosity of 69%)is formed by utilizing a stable and controllable solvent exchange rate,thereby constructing abundant channels for the transportation of ions within the battery.Moreover,the amide groups in the PMIA molecular structure further confer the separator with excellent wettability,enabling it to possess outstanding electrolyte absorption capacity(electrolyte absorption rate of 270%).As a result,the Li||LFP full cell with PMIA separator exhibits excellent capacity and cycling stability,maintaining a reversible specific capacity of 105.6 mAh g^(-1)after 600 cycles at 5 C.And Li||NCM811 full cell with PMIA separator show no significant degradation(168.1 mAh g^(-1)at 0.5 C)after long-cycle at high temperature.These results indicate the potential of the PMIA separator for high thermal stability and high energy battery,and the scalability of this technology also provides new ideas and directions for the preparation of separators with superior comprehensive performance.
