Rechargeable aluminum batteries hold great promise for high energy density and low-cost energy storage applications but are stalled by severe electrochemical side reactions(e.g.,dendrite,passivation,and corrosion)at a...Rechargeable aluminum batteries hold great promise for high energy density and low-cost energy storage applications but are stalled by severe electrochemical side reactions(e.g.,dendrite,passivation,and corrosion)at aluminum(Al)metal anode.Here,we design an aluminum ion battery with an Al-free configuration to circumvent the problems caused by the above side reactions.The feasibility of Al_(x)MnO_(2)·nH_(2)O cathode in aluminum ion batteries is revealed in conjunction with TiO_(2) anodes by using the optimal 5 M Al(OTF)_(3) electrolyte.The as-assembled aluminum ion battery enables high initial discharge capacity of 370.4 mAh g^(−1) at 30 mA g^(−1),favorable stability with low irreversible capacity loss,and enhanced safety.Further,the mechanism is intensively elucidated by multiple characterization results,indicative of the Al^(3+)ions(de)intercalation redox chemistry.Revealed by empirical analyses,the capacity contribution of high-voltage plateau,corresponding to the disproportionation reaction of Mn^(3+)in an Al_(x)MnO_(2)·nH_(2)O battery system,tends to increase with the increasing electrolyte concentration.Our findings may provide fresh impetus to the rational design of aluminum ion batteries with excellent electrochemical properties.展开更多
The implementation of synthetic polymer membranes in gas separations,ranging from natural gas sweetening,hydrogen separation,helium recovery,carbon capture,oxygen/nitrogen enrichment,etc.,has stimulated the vigorous d...The implementation of synthetic polymer membranes in gas separations,ranging from natural gas sweetening,hydrogen separation,helium recovery,carbon capture,oxygen/nitrogen enrichment,etc.,has stimulated the vigorous development of high-performance membrane materials.However,size-sieving types of synthetic polymer membranes are frequently subject to a trade-off between permeability and selectivity,primarily due to the lack of ability to boost fractional free volume while simultaneously controlling the micropore size distribution.Herein,we review recent research progress on microporosity manipulation in high-free-volume polymeric gas separation membranes and their gas separation performance,with an emphasis on membranes with hourglass-shaped or bimodally distributed microcavities.State-of-the-art strategies to construct tailorable and hierarchically microporous structures,microporosity characterization,and microcavity architecture that govern gas separation performance are systematically summarized.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.22075028)the Beijing Institute of Technology Research Fund Program for Young Scholars(No.XSQD-202108005).
文摘Rechargeable aluminum batteries hold great promise for high energy density and low-cost energy storage applications but are stalled by severe electrochemical side reactions(e.g.,dendrite,passivation,and corrosion)at aluminum(Al)metal anode.Here,we design an aluminum ion battery with an Al-free configuration to circumvent the problems caused by the above side reactions.The feasibility of Al_(x)MnO_(2)·nH_(2)O cathode in aluminum ion batteries is revealed in conjunction with TiO_(2) anodes by using the optimal 5 M Al(OTF)_(3) electrolyte.The as-assembled aluminum ion battery enables high initial discharge capacity of 370.4 mAh g^(−1) at 30 mA g^(−1),favorable stability with low irreversible capacity loss,and enhanced safety.Further,the mechanism is intensively elucidated by multiple characterization results,indicative of the Al^(3+)ions(de)intercalation redox chemistry.Revealed by empirical analyses,the capacity contribution of high-voltage plateau,corresponding to the disproportionation reaction of Mn^(3+)in an Al_(x)MnO_(2)·nH_(2)O battery system,tends to increase with the increasing electrolyte concentration.Our findings may provide fresh impetus to the rational design of aluminum ion batteries with excellent electrochemical properties.
基金S.Luo and S.Zhang gratefully acknowledge the financial support from the National Natural Science Foundation of China(22008243,22090063,21890760)the International Partner Program of CAS(122111KYSB20200035)+1 种基金the Project of Stable Support for Youth Team in Basic Research Field of CAS(YSBR-017).R.Guo acknowledges the financial support from the Division of Chemical Sciences,Biosciences,and Geosciences,Office of Basic Energy Sciences of the U.S.Department of Energy(DOE),under award no.DE-SC0019024from the U.S.National Science Foundation under Cooperative Agreement No.EEC-1647722。
文摘The implementation of synthetic polymer membranes in gas separations,ranging from natural gas sweetening,hydrogen separation,helium recovery,carbon capture,oxygen/nitrogen enrichment,etc.,has stimulated the vigorous development of high-performance membrane materials.However,size-sieving types of synthetic polymer membranes are frequently subject to a trade-off between permeability and selectivity,primarily due to the lack of ability to boost fractional free volume while simultaneously controlling the micropore size distribution.Herein,we review recent research progress on microporosity manipulation in high-free-volume polymeric gas separation membranes and their gas separation performance,with an emphasis on membranes with hourglass-shaped or bimodally distributed microcavities.State-of-the-art strategies to construct tailorable and hierarchically microporous structures,microporosity characterization,and microcavity architecture that govern gas separation performance are systematically summarized.
