Restricted by their energy storage mechanism,current energy storage devices have certain drawbacks,such as low power density for batteries and low energy density for supercapacitors.Fortunately,the nearest ion capacit...Restricted by their energy storage mechanism,current energy storage devices have certain drawbacks,such as low power density for batteries and low energy density for supercapacitors.Fortunately,the nearest ion capacitors,such as lithium-ion and sodium-ion capacitors containing battery-type and capacitor-type electrodes,may allow achieving both high energy and power densities.For the inspiration,a new zinc-ion capacitor(ZIC)has been designed and realized by assembling the free-standing manganese dioxide-carbon nanotubes(MnO2-CNTs)battery-type cathode and MXene(Ti3C2Tx)capacitortype anode in an aqueous electrolyte.The ZIC can avoid the insecurity issues that frequently occurred in lithium-ion and sodium-ion capacitors in organic electrolytes.As expected,the ZIC in an aqueous liquid electrolyte exhibits excellent electrochemical performance(based on the total weight of cathode and anode),such as a high specific capacitance of 115.1 F g?1(1 mV s?1),high energy density of 98.6 Wh kg?1(77.5 W kg?1),high power density of 2480.6 W kg?1(29.7 Wh kg?1),and high capacitance retention of^83.6%of its initial capacitance(15,000 cycles).Even in an aqueous gel electrolyte,the ZIC also exhibits excellent performance.This work provides an essential strategy for designing next-generation high-performance energy storage devices.展开更多
The porous medium has an important effect on hydrate formation.In this paper,the formation process and the gas storage capacity of the methane hydrate were investigated with A-type zeolite and Sodium Dodecyl Sulfate (...The porous medium has an important effect on hydrate formation.In this paper,the formation process and the gas storage capacity of the methane hydrate were investigated with A-type zeolite and Sodium Dodecyl Sulfate (SDS) existing in the system.The results show that A-type zeolite can influence methane hydrate formation.At the temperature of 273.5 K and pressure of 8.3 MPa,the distilled water with A-type zeolite can form methane hydrate with gaseous methane in 12 hours.The formation process of the system with A-type zeolite was quite steady and the amount of A-type zeolite can influence the gas storage capacity significantly.The adding of A-type zeolite with 0.067 g·(g water)-1 into 2×10-3 g·g-1 SDS-water solution can increase the gas storage capacity,and the maximum increase rate was 31%.Simultaneously the promotion effect on hydrate formation of 3A-type zeolite is much more obvious than that of 5A-type zeolite when the water adding amounts are 0.033 g·g-1 and 0.067 g·g-1 at the experimental conditions.展开更多
In order to assess the electrical energy storage technologies,the thermo-economy for both capacity-type and power-type energy storage are comprehensively investigated with consideration of political,environmental and ...In order to assess the electrical energy storage technologies,the thermo-economy for both capacity-type and power-type energy storage are comprehensively investigated with consideration of political,environmental and social influence.And for the first time,the Exergy Economy Benefit Ratio(EEBR)is proposed with thermo-economic model and applied to three different storage systems in various scenarios,including pumped storage,compressed air energy storage and flywheel energy storage.The impact of the total system efficiency,annual utilization hour,life time,and other key factors are also analyzed.The results show that the EEBRs of pumped storage and compressed air energy storage under peak load shaving condition and flywheel energy storage under frequency modulation service condition are all larger than zero,which means they are all thermo-economically feasible.With extra consideration of political,environmental and social impact,the exergy cost could reduce by about 25%and the EEBR doubles.The sensitivity analysis indicates the similarity and diversity of influence to EEBR between capacity-type and power-type energy storage systems.The former is that energy efficiency is the dominated factor for all three storage systems.The latter is that the difference of exergy benefit mode causes variety in other major factors.For energy-type storage system,like pumped storage and compressed air storage,the peak-to-valley price ratio is very sensitive in energy arbitrage.For power-type storage system,like flywheel storage,the mileage ratio is in leading position in auxiliary service benefit by mileage.In the three cases studied,the pumped storage has the best thermo-economy;the compressed air energy storage is the second,and the flywheel energy storage is the third.The main reason is that the pumped storage has the least non-exergy cost,and flywheel has the most.展开更多
基金supported by the Anhui Provincial Natural Science Foundation(1908085QF251)Foundation for the Introduction of High-Level Talents of Anhui University(S020118002/061)+1 种基金National Natural Science Foundation of China(11704002)Support Project of Outstanding Young Talents in Anhui Provincial Universities(gxyqZD2018006).
文摘Restricted by their energy storage mechanism,current energy storage devices have certain drawbacks,such as low power density for batteries and low energy density for supercapacitors.Fortunately,the nearest ion capacitors,such as lithium-ion and sodium-ion capacitors containing battery-type and capacitor-type electrodes,may allow achieving both high energy and power densities.For the inspiration,a new zinc-ion capacitor(ZIC)has been designed and realized by assembling the free-standing manganese dioxide-carbon nanotubes(MnO2-CNTs)battery-type cathode and MXene(Ti3C2Tx)capacitortype anode in an aqueous electrolyte.The ZIC can avoid the insecurity issues that frequently occurred in lithium-ion and sodium-ion capacitors in organic electrolytes.As expected,the ZIC in an aqueous liquid electrolyte exhibits excellent electrochemical performance(based on the total weight of cathode and anode),such as a high specific capacitance of 115.1 F g?1(1 mV s?1),high energy density of 98.6 Wh kg?1(77.5 W kg?1),high power density of 2480.6 W kg?1(29.7 Wh kg?1),and high capacitance retention of^83.6%of its initial capacitance(15,000 cycles).Even in an aqueous gel electrolyte,the ZIC also exhibits excellent performance.This work provides an essential strategy for designing next-generation high-performance energy storage devices.
基金Supported by the National Natural Science Foundation of China （50876107）, the National Basic Research Program of China （2009CB219504）, NSFC-Guangdong Union Foundation （NSFC-U0733033） and CAS Program （KGCX2-YW-805）.
文摘The porous medium has an important effect on hydrate formation.In this paper,the formation process and the gas storage capacity of the methane hydrate were investigated with A-type zeolite and Sodium Dodecyl Sulfate (SDS) existing in the system.The results show that A-type zeolite can influence methane hydrate formation.At the temperature of 273.5 K and pressure of 8.3 MPa,the distilled water with A-type zeolite can form methane hydrate with gaseous methane in 12 hours.The formation process of the system with A-type zeolite was quite steady and the amount of A-type zeolite can influence the gas storage capacity significantly.The adding of A-type zeolite with 0.067 g·(g water)-1 into 2×10-3 g·g-1 SDS-water solution can increase the gas storage capacity,and the maximum increase rate was 31%.Simultaneously the promotion effect on hydrate formation of 3A-type zeolite is much more obvious than that of 5A-type zeolite when the water adding amounts are 0.033 g·g-1 and 0.067 g·g-1 at the experimental conditions.
基金funded by National Key R&D Plan(2017YFB0903605)National Natural Science Foundation of China(51606185)+2 种基金International Partnership Program,Bureau of International Cooperation of Chinese Academy of Sciences(182211KYSB20170029)Science and Technology Plan Program of Guizhou Province([2017]1163)Beijing Key Laboratory of Distributed Combined Cooling Heating and Power System.
文摘In order to assess the electrical energy storage technologies,the thermo-economy for both capacity-type and power-type energy storage are comprehensively investigated with consideration of political,environmental and social influence.And for the first time,the Exergy Economy Benefit Ratio(EEBR)is proposed with thermo-economic model and applied to three different storage systems in various scenarios,including pumped storage,compressed air energy storage and flywheel energy storage.The impact of the total system efficiency,annual utilization hour,life time,and other key factors are also analyzed.The results show that the EEBRs of pumped storage and compressed air energy storage under peak load shaving condition and flywheel energy storage under frequency modulation service condition are all larger than zero,which means they are all thermo-economically feasible.With extra consideration of political,environmental and social impact,the exergy cost could reduce by about 25%and the EEBR doubles.The sensitivity analysis indicates the similarity and diversity of influence to EEBR between capacity-type and power-type energy storage systems.The former is that energy efficiency is the dominated factor for all three storage systems.The latter is that the difference of exergy benefit mode causes variety in other major factors.For energy-type storage system,like pumped storage and compressed air storage,the peak-to-valley price ratio is very sensitive in energy arbitrage.For power-type storage system,like flywheel storage,the mileage ratio is in leading position in auxiliary service benefit by mileage.In the three cases studied,the pumped storage has the best thermo-economy;the compressed air energy storage is the second,and the flywheel energy storage is the third.The main reason is that the pumped storage has the least non-exergy cost,and flywheel has the most.
