Fluorine-free proton exchange membranes(PEMs)capable of healing from physical damage are important for PEM fuel cells(PEMFCs)with extended service life and enhanced reliability.Herein,highly elastic fluorine-free PEMs...Fluorine-free proton exchange membranes(PEMs)capable of healing from physical damage are important for PEM fuel cells(PEMFCs)with extended service life and enhanced reliability.Herein,highly elastic fluorine-free PEMs with excellent self-healing ability and high proton conductivity are fabricated through complexation of phytic acid(PA)with sulfonated polyvinyl alcohol(SPVA),followed by subsequent grafting of SPVA with positively charged 4-(1H-imidazol-1-yl)benzenecarbaldehyde(IBZ).Compared with recast Nafion membranes,the as-prepared SPVA-IBZ/PA membranes exhibit an enhanced mechanical strength and elasticity and can spontaneously recover from a^50%strain to their initial states within^30 s at room temperature.Meanwhile,the SPVA-IBZ/PA membranes have a proton conductivity of^0.095 S cm-1at^70°C,which is higher than that of recast Nafion membranes.The hydrogen-powered PEMFCs using the SPVA-IBZ/PA membranes,which show an open circuit voltage of^0.98 V and maximum power density of^609 mW cm-2,exhibit a satisfactory cell performance.Importantly,the SPVA-IBZ/PA membranes can spontaneously heal mechanical damage of several tens of micrometers in size and restore their original proton conductivity and cell performance under the working conditions of PEMFCs.展开更多
基金supported by the National Natural Science Foundation of China(21774049 and 21905105)。
文摘Fluorine-free proton exchange membranes(PEMs)capable of healing from physical damage are important for PEM fuel cells(PEMFCs)with extended service life and enhanced reliability.Herein,highly elastic fluorine-free PEMs with excellent self-healing ability and high proton conductivity are fabricated through complexation of phytic acid(PA)with sulfonated polyvinyl alcohol(SPVA),followed by subsequent grafting of SPVA with positively charged 4-(1H-imidazol-1-yl)benzenecarbaldehyde(IBZ).Compared with recast Nafion membranes,the as-prepared SPVA-IBZ/PA membranes exhibit an enhanced mechanical strength and elasticity and can spontaneously recover from a^50%strain to their initial states within^30 s at room temperature.Meanwhile,the SPVA-IBZ/PA membranes have a proton conductivity of^0.095 S cm-1at^70°C,which is higher than that of recast Nafion membranes.The hydrogen-powered PEMFCs using the SPVA-IBZ/PA membranes,which show an open circuit voltage of^0.98 V and maximum power density of^609 mW cm-2,exhibit a satisfactory cell performance.Importantly,the SPVA-IBZ/PA membranes can spontaneously heal mechanical damage of several tens of micrometers in size and restore their original proton conductivity and cell performance under the working conditions of PEMFCs.
