The pyromellitic dianhydride（PMDA） crosslinked poly（vinyl alcohol）（PVA） was coated on top of the PAN ultrafiltration membrane to form a PVA/PAN composite PV membranes for wastewater desalination. The composite m...The pyromellitic dianhydride（PMDA） crosslinked poly（vinyl alcohol）（PVA） was coated on top of the PAN ultrafiltration membrane to form a PVA/PAN composite PV membranes for wastewater desalination. The composite membranes have high application value in industrial wastewater treatment. By varying the membrane fabrication parameters including the weight percent（wt%） of the PMDA, the crosslink temperature and duration, membrane with the best desalination performance was obtained. The composite membrane with a 2-lm-thick PVA selective layer containing 20 wt% of PMDA and being crosslinked at 100 °C for 2 h showed the highest Na Cl rejection of 99.98% with a water flux of 32.26 L/（m^2 h）at 70 °C using the 35,000 ppm Na Cl aqueous solution as feed. FTIR spectroscopy, wide-angle X-ray diffraction, thermogravimetric analysis and scanning electron microscope have been used to characterize the structures and properties of both the crosslinked PVA dense films and PVA/PAN composite membranes. The effects of the concentrations of PMDA,the crosslinking time and temperature to the membrane water contact angle, swelling degree, salt rejection and water flux were systematically studied.展开更多
Monodisperse crosslinked poly(chloromethylstyrene-co-divinylbenzene)(poly(CMSt-co-DVB))microsphereswere prepared by distillation-precipitation copolymerization of chloromethylstyrene(CMSt)and divinylbenzene(DVB)inneat...Monodisperse crosslinked poly(chloromethylstyrene-co-divinylbenzene)(poly(CMSt-co-DVB))microsphereswere prepared by distillation-precipitation copolymerization of chloromethylstyrene(CMSt)and divinylbenzene(DVB)inneat acetonitrile.The polymer particles had clean surfaces due to the absence of any added stabilizer.The size of the particlesranges from 2.59 μm to 3.19 μm and with mono-dispersity around 1.002-1.014.The effects of monomer feed incopolymerization on the microsphere formation were described.The polymer microspheres were characterized by SEM andchlorinity elemental analysis.展开更多
Surface chemical modification of polyolefin separators for lithium ion batteries is attempted to reduce the thermal shrinkage, which is im- portant for the battery energy density. In this study, we grafted organic/ino...Surface chemical modification of polyolefin separators for lithium ion batteries is attempted to reduce the thermal shrinkage, which is im- portant for the battery energy density. In this study, we grafted organic/inorganic hybrid crosslinked networks on the separators, simply by grafting polymerization and condensation reaction. The considerable silicon-oxygen crosslinked heat-resistance networks are responsible for the reduced thermal shrinkage. The strong chemical bonds between networks and separators promise enough mechanical support even at high temperature. The shrinkage at 150 ℃ for 30 min in the mechanical direction was 38.6% and 4.6% for the pristine and present graft-modified separators, respectively. Meanwhile, the grafting organic-inorganic hybrid crosslink networks mainly occupied part of void in the internal pores of the separators, so the thicknesses of the graft-modified separators were similar with the pristine one. The half cells prepared with the modified separators exhibited almost identical electrochemical properties to those with the commercial separators, thus proving that, in order to enhance the thermal stability of lithium ion battery, this kind of grafting-modified separators may be a better alternative to conventional silica nanoparticle layers-coated polyolefin separators.展开更多
High-voltage lithium metal batteries(LMBs)have been considered promising next-generation highenergy-density batteries.However,commercial carbonate electrolytes can scarcely be employed in LMBs owing to their poor comp...High-voltage lithium metal batteries(LMBs)have been considered promising next-generation highenergy-density batteries.However,commercial carbonate electrolytes can scarcely be employed in LMBs owing to their poor compatibility with metallic lithium.N,N-dimethylacrylamide(DMAA)-a crosslinkable solubilizer with a high Gutmann donor number-is employed to facilitate the dissolution of insoluble lithium nitrate(LiNO3)in carbonate-based electrolytes and to form gel polymer electrolytes(GPEs)through in situ polymerization.The Lit solvation structure of the GPEs is regulated using LiNO3 and DMAA,which suppresses the decomposition of LiPFe and facilitates the formation of an inorganic-rich solid electrolyte interface.Consequently,the Coulombic efficiency(CE)of the LillCu cell assembled with a GPE increases to 98.5%at room temperature,and the high-voltage LillNCM622 cell achieves a capacity retention of 80.1%with a high CE of 99.5%after 400 cycles.The bifunctional polymer electrolytes are anticipated to pave the way for next-generation high-voltage LMBs.展开更多
基金supported by the Higher Education and High-quality and World-class Universities (PY201618)the National Natural Science Foundation of China (Contract Grant Number 51373014)the National Natural Science Foundation of China (Contract Grant Number 51403012)
文摘The pyromellitic dianhydride（PMDA） crosslinked poly（vinyl alcohol）（PVA） was coated on top of the PAN ultrafiltration membrane to form a PVA/PAN composite PV membranes for wastewater desalination. The composite membranes have high application value in industrial wastewater treatment. By varying the membrane fabrication parameters including the weight percent（wt%） of the PMDA, the crosslink temperature and duration, membrane with the best desalination performance was obtained. The composite membrane with a 2-lm-thick PVA selective layer containing 20 wt% of PMDA and being crosslinked at 100 °C for 2 h showed the highest Na Cl rejection of 99.98% with a water flux of 32.26 L/（m^2 h）at 70 °C using the 35,000 ppm Na Cl aqueous solution as feed. FTIR spectroscopy, wide-angle X-ray diffraction, thermogravimetric analysis and scanning electron microscope have been used to characterize the structures and properties of both the crosslinked PVA dense films and PVA/PAN composite membranes. The effects of the concentrations of PMDA,the crosslinking time and temperature to the membrane water contact angle, swelling degree, salt rejection and water flux were systematically studied.
基金This work was funded by the financial support of the National Natural Science Foundation of China(Project No.20274018)Nankai University.
文摘Monodisperse crosslinked poly(chloromethylstyrene-co-divinylbenzene)(poly(CMSt-co-DVB))microsphereswere prepared by distillation-precipitation copolymerization of chloromethylstyrene(CMSt)and divinylbenzene(DVB)inneat acetonitrile.The polymer particles had clean surfaces due to the absence of any added stabilizer.The size of the particlesranges from 2.59 μm to 3.19 μm and with mono-dispersity around 1.002-1.014.The effects of monomer feed incopolymerization on the microsphere formation were described.The polymer microspheres were characterized by SEM andchlorinity elemental analysis.
基金supported by the MOST(Grant No.2013CB934000,2014DFG71590,2011CB935902,2010DFA72760,2011CB711202,2013AA050903,2011AA11A257 and 2011AA11A254)China Postdoctoral Science Foundation(Grant No.2013M530599 and 2013M540929)+2 种基金Tsinghua University Initiative Scientific Research Program(Grant No.2010THZ08116,2011THZ08139,2011THZ01004 and 2012THZ08129)the State Key Laboratory of Automotive Safety and Energy(No.ZZ2012-011)Suzhou(Wujiang)Automotive Research Institute,Tsinghua University,Project No.2012WJ-A-01
文摘Surface chemical modification of polyolefin separators for lithium ion batteries is attempted to reduce the thermal shrinkage, which is im- portant for the battery energy density. In this study, we grafted organic/inorganic hybrid crosslinked networks on the separators, simply by grafting polymerization and condensation reaction. The considerable silicon-oxygen crosslinked heat-resistance networks are responsible for the reduced thermal shrinkage. The strong chemical bonds between networks and separators promise enough mechanical support even at high temperature. The shrinkage at 150 ℃ for 30 min in the mechanical direction was 38.6% and 4.6% for the pristine and present graft-modified separators, respectively. Meanwhile, the grafting organic-inorganic hybrid crosslink networks mainly occupied part of void in the internal pores of the separators, so the thicknesses of the graft-modified separators were similar with the pristine one. The half cells prepared with the modified separators exhibited almost identical electrochemical properties to those with the commercial separators, thus proving that, in order to enhance the thermal stability of lithium ion battery, this kind of grafting-modified separators may be a better alternative to conventional silica nanoparticle layers-coated polyolefin separators.
基金supported by the National Natural Science Foundation of China(51971250)China Postdoctoral Science Foundation(2023M733933)+1 种基金the Natural Science Foundation of Hunan Province(2023J40759)the State Key Laboratory of Powder Metallurgy at Central South University.
文摘High-voltage lithium metal batteries(LMBs)have been considered promising next-generation highenergy-density batteries.However,commercial carbonate electrolytes can scarcely be employed in LMBs owing to their poor compatibility with metallic lithium.N,N-dimethylacrylamide(DMAA)-a crosslinkable solubilizer with a high Gutmann donor number-is employed to facilitate the dissolution of insoluble lithium nitrate(LiNO3)in carbonate-based electrolytes and to form gel polymer electrolytes(GPEs)through in situ polymerization.The Lit solvation structure of the GPEs is regulated using LiNO3 and DMAA,which suppresses the decomposition of LiPFe and facilitates the formation of an inorganic-rich solid electrolyte interface.Consequently,the Coulombic efficiency(CE)of the LillCu cell assembled with a GPE increases to 98.5%at room temperature,and the high-voltage LillNCM622 cell achieves a capacity retention of 80.1%with a high CE of 99.5%after 400 cycles.The bifunctional polymer electrolytes are anticipated to pave the way for next-generation high-voltage LMBs.
