The interconnection of polarization and phase in electromagnetic scattering process has attracted both fundamental and practical interest.Here we propose the principle and experimental demonstration of a scatteringcon...The interconnection of polarization and phase in electromagnetic scattering process has attracted both fundamental and practical interest.Here we propose the principle and experimental demonstration of a scatteringcontrol mechanism based on the simultaneous control of polarization and phase via a continuously shaped planar metasurface.Under circularly polarized illumination,the scattering is redirected to off-specular direction,leading to significant reduction of the scattering cross section.Theoretical investigation shows that the underlying physical mechanism is the spin-dependent phase modulation in the anisotropic scattering process.Our approach would provide valuable guidance for the full control of electromagnetic wave for diverse applications.展开更多
Lignin is the second most abundant and the only nature polymer rich in aromatic units.Although aromatic-unit-rich precursors often yield soft carbon after carbonization,the side chains in lignin crosslink with the aro...Lignin is the second most abundant and the only nature polymer rich in aromatic units.Although aromatic-unit-rich precursors often yield soft carbon after carbonization,the side chains in lignin crosslink with the aromatic units and form a rigid three-dimensional(3D)structure which eventually leads to hard carbons.Through a graphene oxide-catalyzed decomposition and repolymerization process,we successfully reconstructed lignin by partially tailoring the side chains.Compared to directly carbonized lignin,the carbonized reconstructed lignin possesses significantly fewer defects,86%fewer oxygen-functionalities,82%fewer micropores,and narrower interlayer space.These parameters can be tuned by the amount of catalysts(graphene oxide).When tested as anode for K-ion and Na-ion batteries,the carbonized reconstructed lignin delivers notably higher capacity at low-potential range(especially for Na-storage),shows much-improved performance at high current density,and most importantly,reduces voltage hysteresis between discharge and charge process by more than 50%,which is critical to the energy efficiency of the energy storage system.Our study reveals that the voltage hysteresis in K-storage is much severer than that in Na-storage for all samples.For practical K-ion battery applications,the voltage hysteresis deserves more attention in future electrode materials design and the reconstruct ion strategy introduced in this work provides potential low-cost solution.展开更多
基金the China Triumph International Engineering Co. Ltd.(CTIEC),Shanghai,China,which offers generous financial support for this work
文摘The interconnection of polarization and phase in electromagnetic scattering process has attracted both fundamental and practical interest.Here we propose the principle and experimental demonstration of a scatteringcontrol mechanism based on the simultaneous control of polarization and phase via a continuously shaped planar metasurface.Under circularly polarized illumination,the scattering is redirected to off-specular direction,leading to significant reduction of the scattering cross section.Theoretical investigation shows that the underlying physical mechanism is the spin-dependent phase modulation in the anisotropic scattering process.Our approach would provide valuable guidance for the full control of electromagnetic wave for diverse applications.
基金This work is funded by Alberta Innovates through the Alberta Bio Future,Lignin Challenge 1.0 and Lignin Pursuit subprograms。
文摘Lignin is the second most abundant and the only nature polymer rich in aromatic units.Although aromatic-unit-rich precursors often yield soft carbon after carbonization,the side chains in lignin crosslink with the aromatic units and form a rigid three-dimensional(3D)structure which eventually leads to hard carbons.Through a graphene oxide-catalyzed decomposition and repolymerization process,we successfully reconstructed lignin by partially tailoring the side chains.Compared to directly carbonized lignin,the carbonized reconstructed lignin possesses significantly fewer defects,86%fewer oxygen-functionalities,82%fewer micropores,and narrower interlayer space.These parameters can be tuned by the amount of catalysts(graphene oxide).When tested as anode for K-ion and Na-ion batteries,the carbonized reconstructed lignin delivers notably higher capacity at low-potential range(especially for Na-storage),shows much-improved performance at high current density,and most importantly,reduces voltage hysteresis between discharge and charge process by more than 50%,which is critical to the energy efficiency of the energy storage system.Our study reveals that the voltage hysteresis in K-storage is much severer than that in Na-storage for all samples.For practical K-ion battery applications,the voltage hysteresis deserves more attention in future electrode materials design and the reconstruct ion strategy introduced in this work provides potential low-cost solution.
