Dramatic fall in costs of renewable energy in the last 24 months has not only accelerated the replacement of fossil fuels by renewable energy in electricity generation. The low cost renewable electricity is now starti...Dramatic fall in costs of renewable energy in the last 24 months has not only accelerated the replacement of fossil fuels by renewable energy in electricity generation. The low cost renewable electricity is now starting to replace fossil fuels in other sectors. One reason is that renewable electricity is now cheaper per unit energy than oil, about the same price as fossil methan but, still, more expensive than coal. Another reason is that electricity often offer other opportunities, such as cheaper transport, better control, higher energy efficiency in final production of energy services and lower local environmental costs.展开更多
As a critical component of alkaline fuel cells, anion exchange membranes determine the energy efficiency, output power density and the long term stability. Recently, the anion exchange membranes with gemini-cation sid...As a critical component of alkaline fuel cells, anion exchange membranes determine the energy efficiency, output power density and the long term stability. Recently, the anion exchange membranes with gemini-cation side chains exhibit superior ion conductivity due to their good nanophase separation. However, the costly and complicated synthesis limits their scaling up and commercialization. To address this problem, a convenient synthetic procedure under mild conditions is well developed. A tertiary amine precursor is introduced onto the polymer by the nucleophilic substitution reaction to avoid the conventional chloro/bromo-methylation. Followed by a simple Menshutkin reaction with 6- bromo-N,N,N-trimethylhexan-1-am inium bromide, the polym er electrolytes are obtained in a high yield. The resulting anion exchange membranes with high conductivity, good fuel cell performance and restricted swelling suggest the potential for the application in fuel cell devices.展开更多
The most viable path to alleviate the Global Climate Change is the substitution of fossil fuel power plants for electricity generation with renewable energy units.This substitution requires the development of very lar...The most viable path to alleviate the Global Climate Change is the substitution of fossil fuel power plants for electricity generation with renewable energy units.This substitution requires the development of very large energy storage capacity,with the inherent thermodynamic irreversibility of the storage-recovery process.Currently,the world experiences a significant growth in the numbers of electric vehicles with large batteries.A fleet of electric vehicles is equivalent to an efficient storage capacity system to supplement the energy storage system of the electricity grid.Calculations based on the hourly demand-supply data of ERCOT,a very large electricity grid,show that a fleet of electric vehicles cannot provide all the needed capacity and the remaining capacity must be met by hydrogen.Even though the storage capacity of the batteries is close to 1–2%of the needed storage capacity of the grid,the superior round-trip storage efficiency of batteries reduces the energy dissipation associated with the storage and recovery processes by up to 38%and the total hydrogen storage capacity by up to 50%.The study also shows that anticipated improvements in the round-trip efficiencies of batteries are almost three times more effective than improvements in hydrogen storage systems.展开更多
文摘Dramatic fall in costs of renewable energy in the last 24 months has not only accelerated the replacement of fossil fuels by renewable energy in electricity generation. The low cost renewable electricity is now starting to replace fossil fuels in other sectors. One reason is that renewable electricity is now cheaper per unit energy than oil, about the same price as fossil methan but, still, more expensive than coal. Another reason is that electricity often offer other opportunities, such as cheaper transport, better control, higher energy efficiency in final production of energy services and lower local environmental costs.
基金supported by the National Natural Science Foundation of China (21720102003, 91534203 and 21522607)the Fundamental Research Funds for the Central Universities (WK2060190072 and WK2340000066)
文摘As a critical component of alkaline fuel cells, anion exchange membranes determine the energy efficiency, output power density and the long term stability. Recently, the anion exchange membranes with gemini-cation side chains exhibit superior ion conductivity due to their good nanophase separation. However, the costly and complicated synthesis limits their scaling up and commercialization. To address this problem, a convenient synthetic procedure under mild conditions is well developed. A tertiary amine precursor is introduced onto the polymer by the nucleophilic substitution reaction to avoid the conventional chloro/bromo-methylation. Followed by a simple Menshutkin reaction with 6- bromo-N,N,N-trimethylhexan-1-am inium bromide, the polym er electrolytes are obtained in a high yield. The resulting anion exchange membranes with high conductivity, good fuel cell performance and restricted swelling suggest the potential for the application in fuel cell devices.
基金This research was partly supported by the Tex Moncrief Chair of Engineering at TCU.
文摘The most viable path to alleviate the Global Climate Change is the substitution of fossil fuel power plants for electricity generation with renewable energy units.This substitution requires the development of very large energy storage capacity,with the inherent thermodynamic irreversibility of the storage-recovery process.Currently,the world experiences a significant growth in the numbers of electric vehicles with large batteries.A fleet of electric vehicles is equivalent to an efficient storage capacity system to supplement the energy storage system of the electricity grid.Calculations based on the hourly demand-supply data of ERCOT,a very large electricity grid,show that a fleet of electric vehicles cannot provide all the needed capacity and the remaining capacity must be met by hydrogen.Even though the storage capacity of the batteries is close to 1–2%of the needed storage capacity of the grid,the superior round-trip storage efficiency of batteries reduces the energy dissipation associated with the storage and recovery processes by up to 38%and the total hydrogen storage capacity by up to 50%.The study also shows that anticipated improvements in the round-trip efficiencies of batteries are almost three times more effective than improvements in hydrogen storage systems.
