A new amphoteric membrane was prepared by blending long-side-chain sulfonated poly(2,6-dimethyl-1,4-phenylene oxide)(S-L-PPO)and polybenzimidazole(PBI)for vanadium redox flow battery(VRFB)application.An acid-base pair...A new amphoteric membrane was prepared by blending long-side-chain sulfonated poly(2,6-dimethyl-1,4-phenylene oxide)(S-L-PPO)and polybenzimidazole(PBI)for vanadium redox flow battery(VRFB)application.An acid-base pair structure formed between the imidazole of PBI and sulfonic acid of S-L-PPO resulted in lowered swelling ratio.It favors to reduce the vanadium permeation.While,the increased sulfonic acid concentration ensured that proton conductivity was still at a high level.As a result,a better balance between the vanadium ion permeation(6.1×10^-9 cm^2·s^-1)and proton conductivity(50.8 m S·cm^-1)in the S-L-PPO/PBI-10%membrane was achieved.The VRFB performance with S-L-PPO/PBI-10%membrane exhibited an EE of 82.7%,which was higher than those of pristine S-L-PPO(81.8%)and Nafion 212(78.0%)at 120 m A·cm^-2.In addition,the S-LPPO/PBI-10%membrane had a much longer self-discharge duration time(142 h)than that of Nafion 212(23 h).展开更多
For improvement of vanadium redox flow battery （VRB） performance, novel amphoteric semi- interpenetrating membranes （ASIPN） were prepared using poly（ether ether ketone） （PEEK） and polysul- fone （PSf）, the fo...For improvement of vanadium redox flow battery （VRB） performance, novel amphoteric semi- interpenetrating membranes （ASIPN） were prepared using poly（ether ether ketone） （PEEK） and polysul- fone （PSf）, the former bearing sulfonic groups and the latter imidazolium. These two groups form ionic crosslinks between PEEK and PSf; meanwhile, covalent cross links were built between PSf chains with ad- dition of N-（3-aminopropyl）-imidazole. The amphoteric nature of the membrane allows facile proton and anion transport; the IPN structure and the presence of imidazolium cation effectively suppress vanadium ion crossover through the membrane. Therefore, the ASIPN based VRBs show higher Coulombic efficiency and energy efficiency than that assembled with pristine SPEEK and Nation 212 membranes. Our work demonstrates that the ASIPN membranes are promising for VRB applications.展开更多
Salination of solutions of salinity gradient releases large‐scale clean and renewable energy, which can be directly and efficiently transformed into electrical energy using ion‐selective nanofluidic channel membrane...Salination of solutions of salinity gradient releases large‐scale clean and renewable energy, which can be directly and efficiently transformed into electrical energy using ion‐selective nanofluidic channel membranes. However, conventional ion‐selective membranes are typically either cation‐ or anion‐selective. A pH‐switchable system capable of dual cation and anion transport along with salt gradient energy harvesting properties has not been demonstrated in ion‐selective membranes. Here, we constructed an amphoteric heterolayer metal–organic framework (MOF) membrane with subnanochannels modified with carboxylic and amino functional groups. The amphoteric MOF‐composite membrane, AAO/aUiO‐66‐(COOH)2/UiO‐66‐NH2, exhibits pH‐tuneable ion conduction and achieves osmotic energy conversion of 7.4 and 5.7 W/m2 in acidic and alkaline conditions, respectively, using a 50‐fold salt gradient. For different anions but the same cation diffusion transport, the amphoteric membrane produces an outstanding I−/CO32− selectivity of ~4160 and an osmotic energy conversion of ~133.5 W/m2. The amphoteric membrane concept introduces a new pathway to explore the development of ion transport and separation technologies and their application in osmotic energy‐conversion devices and flow batteries.展开更多
基金supported by the National Natural Science Foundation of China(U1808209)Fundamental Research Funds for the Central Universities(DUT18JC40)Liaoning Province Science and Technology Department(201601037)。
文摘A new amphoteric membrane was prepared by blending long-side-chain sulfonated poly(2,6-dimethyl-1,4-phenylene oxide)(S-L-PPO)and polybenzimidazole(PBI)for vanadium redox flow battery(VRFB)application.An acid-base pair structure formed between the imidazole of PBI and sulfonic acid of S-L-PPO resulted in lowered swelling ratio.It favors to reduce the vanadium permeation.While,the increased sulfonic acid concentration ensured that proton conductivity was still at a high level.As a result,a better balance between the vanadium ion permeation(6.1×10^-9 cm^2·s^-1)and proton conductivity(50.8 m S·cm^-1)in the S-L-PPO/PBI-10%membrane was achieved.The VRFB performance with S-L-PPO/PBI-10%membrane exhibited an EE of 82.7%,which was higher than those of pristine S-L-PPO(81.8%)and Nafion 212(78.0%)at 120 m A·cm^-2.In addition,the S-LPPO/PBI-10%membrane had a much longer self-discharge duration time(142 h)than that of Nafion 212(23 h).
基金the financial supports from the National Key Research and Development Program of China (2016YFB0101203)China MOST (Ministry of Science and Technology) Innovation Team in Key Area (2016RA4053)+2 种基金the National Natural Science Foundation of China (21276252)Natural Science Foundation of Liaoning Province (2015020630)State Key Laboratory of Fine Chemicals (Panjin) (JH2014009)
文摘For improvement of vanadium redox flow battery （VRB） performance, novel amphoteric semi- interpenetrating membranes （ASIPN） were prepared using poly（ether ether ketone） （PEEK） and polysul- fone （PSf）, the former bearing sulfonic groups and the latter imidazolium. These two groups form ionic crosslinks between PEEK and PSf; meanwhile, covalent cross links were built between PSf chains with ad- dition of N-（3-aminopropyl）-imidazole. The amphoteric nature of the membrane allows facile proton and anion transport; the IPN structure and the presence of imidazolium cation effectively suppress vanadium ion crossover through the membrane. Therefore, the ASIPN based VRBs show higher Coulombic efficiency and energy efficiency than that assembled with pristine SPEEK and Nation 212 membranes. Our work demonstrates that the ASIPN membranes are promising for VRB applications.
文摘Salination of solutions of salinity gradient releases large‐scale clean and renewable energy, which can be directly and efficiently transformed into electrical energy using ion‐selective nanofluidic channel membranes. However, conventional ion‐selective membranes are typically either cation‐ or anion‐selective. A pH‐switchable system capable of dual cation and anion transport along with salt gradient energy harvesting properties has not been demonstrated in ion‐selective membranes. Here, we constructed an amphoteric heterolayer metal–organic framework (MOF) membrane with subnanochannels modified with carboxylic and amino functional groups. The amphoteric MOF‐composite membrane, AAO/aUiO‐66‐(COOH)2/UiO‐66‐NH2, exhibits pH‐tuneable ion conduction and achieves osmotic energy conversion of 7.4 and 5.7 W/m2 in acidic and alkaline conditions, respectively, using a 50‐fold salt gradient. For different anions but the same cation diffusion transport, the amphoteric membrane produces an outstanding I−/CO32− selectivity of ~4160 and an osmotic energy conversion of ~133.5 W/m2. The amphoteric membrane concept introduces a new pathway to explore the development of ion transport and separation technologies and their application in osmotic energy‐conversion devices and flow batteries.
