Supercapacitors,comprising electrical double-layer capacitors(EDLCs)and pseudocapa-citors,are widely acknowledged as high-power energy storage devices.However,their local structures and fundamental mechanisms remain p...Supercapacitors,comprising electrical double-layer capacitors(EDLCs)and pseudocapa-citors,are widely acknowledged as high-power energy storage devices.However,their local structures and fundamental mechanisms remain poorly understood,and suitable experimental techniques for investigation are also lacking.Recently,nuclear magnetic resonance(NMR)has emerged as a powerful tool for addressing these fundamental issues with high local sensitivity and non-invasiveness.In this paper,we first review the limi-tations of existing characterization methods and highlight the advantages of NMR in investigating mechanisms of supercapacitors.Subsequently,we introduce the basic prin-ciple of ring current effect,NMR-active nuclei,and various NMR techniques employed in exploring energy storage mechanisms including cross polarization(CP)magic angle spinning(MAS)NMR,multiple-quantum(MQ)MAS,two-dimensional exchange spec-troscopy(2D-EXSY)NMR,magnetic resonance imaging(MRI)and pulsed-field gradient(PFG)NMR.Based on this,recent progress in investigating energy storage mechanisms in EDLCs and pseudocapacitors through various NMR techniques is discussed.Finally,an outlook on future directions for NMR research in supercapacitors is offered.展开更多
The environmental problems of global warming and fossil fuel depletion are increasingly severe,and the demand for energy conversion and storage is increasing.Ecological issues such as global warming and fossil fuel de...The environmental problems of global warming and fossil fuel depletion are increasingly severe,and the demand for energy conversion and storage is increasing.Ecological issues such as global warming and fossil fuel depletion are increasingly stringent,increasing energy conversion and storage needs.The rapid development of clean energy,such as solar energy,wind energy and hydrogen energy,is expected to be the key to solve the energy problem.Several excellent literature works have highlighted quantum dots in supercapacitors,lithium-sulfur batteries,and photocatalytic hydrogen production.Here,we outline the latest achievements of quantum dots and their composites materials in those energy storage applications.Moreover,we rationally analyze the shortcomings of quantum dots in energy storage and conversion,and predict the future development trend,challenges,and opportunities of quantum dots research.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.22075064)National Key Laboratory Projects(No.SYSKT20230056).
文摘Supercapacitors,comprising electrical double-layer capacitors(EDLCs)and pseudocapa-citors,are widely acknowledged as high-power energy storage devices.However,their local structures and fundamental mechanisms remain poorly understood,and suitable experimental techniques for investigation are also lacking.Recently,nuclear magnetic resonance(NMR)has emerged as a powerful tool for addressing these fundamental issues with high local sensitivity and non-invasiveness.In this paper,we first review the limi-tations of existing characterization methods and highlight the advantages of NMR in investigating mechanisms of supercapacitors.Subsequently,we introduce the basic prin-ciple of ring current effect,NMR-active nuclei,and various NMR techniques employed in exploring energy storage mechanisms including cross polarization(CP)magic angle spinning(MAS)NMR,multiple-quantum(MQ)MAS,two-dimensional exchange spec-troscopy(2D-EXSY)NMR,magnetic resonance imaging(MRI)and pulsed-field gradient(PFG)NMR.Based on this,recent progress in investigating energy storage mechanisms in EDLCs and pseudocapacitors through various NMR techniques is discussed.Finally,an outlook on future directions for NMR research in supercapacitors is offered.
基金supported by the National Key Research and Development Program of China(2020YFC2005500)the National Natural Science Foundation of China(No.81972901)+2 种基金Science Foundation of China University of Petroleum(No.2462020YXZZ0188,2462019QNXZ02,2462018BJC004)the Academy of Finland(No.330214)the U.S.National Science Foundation(No.2004251).
文摘The environmental problems of global warming and fossil fuel depletion are increasingly severe,and the demand for energy conversion and storage is increasing.Ecological issues such as global warming and fossil fuel depletion are increasingly stringent,increasing energy conversion and storage needs.The rapid development of clean energy,such as solar energy,wind energy and hydrogen energy,is expected to be the key to solve the energy problem.Several excellent literature works have highlighted quantum dots in supercapacitors,lithium-sulfur batteries,and photocatalytic hydrogen production.Here,we outline the latest achievements of quantum dots and their composites materials in those energy storage applications.Moreover,we rationally analyze the shortcomings of quantum dots in energy storage and conversion,and predict the future development trend,challenges,and opportunities of quantum dots research.
