In order to obtain high power density,energy density and safe energy storage lithium ion batteries(LIB)to meet growing demand for electronic products,oxide cathodes have been widely explored in all-solidstate lithium ...In order to obtain high power density,energy density and safe energy storage lithium ion batteries(LIB)to meet growing demand for electronic products,oxide cathodes have been widely explored in all-solidstate lithium batteries(ASSLB)using sulfide solid electrolyte.However,the electrochemical performances are still not satisfactory,due to the high interfacial resistance caused by severe interfacial instability between sulfide solid electrolyte and oxide cathode,especially Ni-rich oxide cathodes,in charge-discharge process.Ni-rich LiNi0.8Co0.1Mn0.1O2(NCM811)material at present is one of the most key cathode candidates to achieve the high energy density up to 300 Wh kg^-1 in liquid LIB,but rarely investigated in ASSLB using sulfide electrolyte.To design the stable interface between NCM811 and sulfide electrolyte should be extremely necessary.In this work,in view of our previous work,LiNbO3 coating with about 1 wt% content is adopted to improve the interfacial stability and the electrochemical performances of NCM811 cathode in ASSLB using Li10GeP2S12 solid electrolyte.Consequently,LiNbO3-coated NCM811 cathode displays the higher discharge capacity and rate performance than the reported oxide electrodes in ASSLB using sulfide solid electrolyte to our knowledge.展开更多
Sound velocity inversion problem based on scattering theory is formulated in terms of a nonlinear integral equation associated with scattered field. Because of its nonlinearity, in practice, linearization algorisms （...Sound velocity inversion problem based on scattering theory is formulated in terms of a nonlinear integral equation associated with scattered field. Because of its nonlinearity, in practice, linearization algorisms （Born/ single scattering approximation） are widely used to obtain an approximate inversion solution. However, the linearized strategy is not congruent with seismic wave propagation mechanics in strong perturbation （heterogeneous） medium. In order to partially dispense with the weak perturbation assumption of the Born approximation, we present a new approach from the following two steps： firstly, to handle the forward scattering by taking into account the second- order Born approximation, which is related to generalized Radon transform （GRT） about quadratic scattering poten- tial; then to derive a nonlinear quadratic inversion formula by resorting to inverse GRT. In our formulation, there is a significant quadratic term regarding scattering potential, and it can provide an amplitude correction for inversion results beyond standard linear inversion. The numerical experiments demonstrate that the linear single scattering inversion is only good in amplitude for relative velocity perturbation （3c/c0） of background media up to 10 %, andits inversion errors are unacceptable for the perturbation beyond 10 %. In contrast, the quadratic inversion can give more accurate amplitude-preserved recovery for the per- turbation up to 40 %. Our inversion scheme is able to manage double scattering effects by estimating a trans- mission factor from an integral over a small area, and therefore, only a small portion of computational time is added to the original linear migration/inversion process.展开更多
The crustal structure in Myanmar can provide valuable information for the eastern margin of the ongoing IndoEurasian collision system.We successively performed H-k stacking of the receiver function and joint inversion...The crustal structure in Myanmar can provide valuable information for the eastern margin of the ongoing IndoEurasian collision system.We successively performed H-k stacking of the receiver function and joint inversion of the receiver function and surface wave dispersion to invert the crustal thickness(H),shear wave velocity(V_(S)),and the V_(P)/V_(S) ratio(k)beneath nine permanent seismic stations in Myanmar.H was found to increase from 26 km in the south and east of the study area to 51 km in the north and west,and the V_(P)/V_(S) ratio was complex and high.Striking differences in the crust were observed for different tectonic areas.In the Indo-Burma Range,the thick crust(H~51 km)and lower velocities may be related to the accretionary wedge from the Indian Plate.In the Central Myanmar Basin,the thin crust(H=26.9-35.5 km)and complex V_(P)/V_(S) ratio and V_(S) suggest extensional tectonics.In the Eastern Shan Plateau,the relatively thick crust and normal V_(P)/V_(S) ratio are consistent with its location along the western edge of the rigid Sunda Block.展开更多
The interfacial instability between Ni-rich layered oxide cathodes and sulfide electrolytes is a serious problem,leading to poor electrochemical properties of all-solid-state lithium batteries(ASSLB).The chemical/elec...The interfacial instability between Ni-rich layered oxide cathodes and sulfide electrolytes is a serious problem,leading to poor electrochemical properties of all-solid-state lithium batteries(ASSLB).The chemical/electrochemical side reactions are considered to be the origin of the interfacial deterioration.However,the influence of chemical and electrochemical side reactions on the interfacial deterioration is rarely studied specifically.In this work,the deterioration mechanism of the interface between LiNi0.85-xCo0.15AlxO2 and Li10GeP2S12 is investigated in detail by combining in/ex-situ Raman spectra and Electrochemical Impedance Spectroscopy(EIS).It can be determined that chemical side reaction between LiNi0.8Co0.15Al0.05O2 and Li10GeP2S12 will occur immediately once contacted,and the interfacial deterioration becomes more serious after charge-discharge process under the dual effects of chemical and electrochemical side reactions.Moreover,our research reveals that the interfacial stability and the cycle performance of ASSLB can be greatly enhanced by increasing Al-substitution for Ni in LiNi0.85-xCo0.15AlxO2.In particular,the capacity retention of LiNi0.6Co0.15Al0.25O2 cathode after 200 cycles can reach 81.9%,much higher than that of LiNi0.8Co0.15Al0.05O2 cathode(12.5%@200 cycles).This work gives an insight to study the interfacial issues between Ni-rich layered oxide cathode and sulfide electrolyte for ASSLBs.展开更多
When two synchronized laser beams illuminate the inner surface of bulk lithium niobate crystals with magnesium doping(5%/mol MgO:LiNbO_(3))under the condition of total reflection,semi-degenerate four-wave mixing(FWM)i...When two synchronized laser beams illuminate the inner surface of bulk lithium niobate crystals with magnesium doping(5%/mol MgO:LiNbO_(3))under the condition of total reflection,semi-degenerate four-wave mixing(FWM)is generated.On this basis,a more sophisticated frequency conversion process on the interface of nonlinear crystal has been researched.The generation mechanism of FWM is associated with the fundamental waves reflected on the inner surface of the nonlinear crystal.Analysis of the phase-matching mechanism confirms that the FWM is radiated by the third-order nonlinear polarized waves,which are stimulated by the third-order nonlinear susceptibility coefficient of the nonlinear crystal.Theoretically calculated and experimentally measured corresponding data have been presented in this article.These results are expected to provide new inspiration for further experimental and theoretical research on frequency conversion in nonlinear crystals.展开更多
基金financially supported partly by the National Key Research and Development Program of China (2018YFB0104302)NSFC (21503148)Major Programs of the Innovation Driven Plan of Guilin (No. 20160203)
文摘In order to obtain high power density,energy density and safe energy storage lithium ion batteries(LIB)to meet growing demand for electronic products,oxide cathodes have been widely explored in all-solidstate lithium batteries(ASSLB)using sulfide solid electrolyte.However,the electrochemical performances are still not satisfactory,due to the high interfacial resistance caused by severe interfacial instability between sulfide solid electrolyte and oxide cathode,especially Ni-rich oxide cathodes,in charge-discharge process.Ni-rich LiNi0.8Co0.1Mn0.1O2(NCM811)material at present is one of the most key cathode candidates to achieve the high energy density up to 300 Wh kg^-1 in liquid LIB,but rarely investigated in ASSLB using sulfide electrolyte.To design the stable interface between NCM811 and sulfide electrolyte should be extremely necessary.In this work,in view of our previous work,LiNbO3 coating with about 1 wt% content is adopted to improve the interfacial stability and the electrochemical performances of NCM811 cathode in ASSLB using Li10GeP2S12 solid electrolyte.Consequently,LiNbO3-coated NCM811 cathode displays the higher discharge capacity and rate performance than the reported oxide electrodes in ASSLB using sulfide solid electrolyte to our knowledge.
基金supported by Innovation Project of Chinese Academy of Sciences and State Key Laboratory of Marine Geology, Tongji University (No. MGK1408)
文摘Sound velocity inversion problem based on scattering theory is formulated in terms of a nonlinear integral equation associated with scattered field. Because of its nonlinearity, in practice, linearization algorisms （Born/ single scattering approximation） are widely used to obtain an approximate inversion solution. However, the linearized strategy is not congruent with seismic wave propagation mechanics in strong perturbation （heterogeneous） medium. In order to partially dispense with the weak perturbation assumption of the Born approximation, we present a new approach from the following two steps： firstly, to handle the forward scattering by taking into account the second- order Born approximation, which is related to generalized Radon transform （GRT） about quadratic scattering poten- tial; then to derive a nonlinear quadratic inversion formula by resorting to inverse GRT. In our formulation, there is a significant quadratic term regarding scattering potential, and it can provide an amplitude correction for inversion results beyond standard linear inversion. The numerical experiments demonstrate that the linear single scattering inversion is only good in amplitude for relative velocity perturbation （3c/c0） of background media up to 10 %, andits inversion errors are unacceptable for the perturbation beyond 10 %. In contrast, the quadratic inversion can give more accurate amplitude-preserved recovery for the per- turbation up to 40 %. Our inversion scheme is able to manage double scattering effects by estimating a trans- mission factor from an integral over a small area, and therefore, only a small portion of computational time is added to the original linear migration/inversion process.
基金supported by the open fund from the Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resource,Institute of Geology,Chinese Academy of Geological Sciences(J1901-16)by the fund from the State Key Laboratory of Geodesy and Earth’s Dynamics,Innovation Academy for Precision Measurement Science and Technology,Chinese Academy of Sciences(S21L6403)。
文摘The crustal structure in Myanmar can provide valuable information for the eastern margin of the ongoing IndoEurasian collision system.We successively performed H-k stacking of the receiver function and joint inversion of the receiver function and surface wave dispersion to invert the crustal thickness(H),shear wave velocity(V_(S)),and the V_(P)/V_(S) ratio(k)beneath nine permanent seismic stations in Myanmar.H was found to increase from 26 km in the south and east of the study area to 51 km in the north and west,and the V_(P)/V_(S) ratio was complex and high.Striking differences in the crust were observed for different tectonic areas.In the Indo-Burma Range,the thick crust(H~51 km)and lower velocities may be related to the accretionary wedge from the Indian Plate.In the Central Myanmar Basin,the thin crust(H=26.9-35.5 km)and complex V_(P)/V_(S) ratio and V_(S) suggest extensional tectonics.In the Eastern Shan Plateau,the relatively thick crust and normal V_(P)/V_(S) ratio are consistent with its location along the western edge of the rigid Sunda Block.
基金financially supported partly by the National Key Research and Development Program of China(2018YFE0111600)Tianjin Sci.&Tech.Program(17YFZCGX00560,18ZXJMTG00040,19JCZDJC31800)。
文摘The interfacial instability between Ni-rich layered oxide cathodes and sulfide electrolytes is a serious problem,leading to poor electrochemical properties of all-solid-state lithium batteries(ASSLB).The chemical/electrochemical side reactions are considered to be the origin of the interfacial deterioration.However,the influence of chemical and electrochemical side reactions on the interfacial deterioration is rarely studied specifically.In this work,the deterioration mechanism of the interface between LiNi0.85-xCo0.15AlxO2 and Li10GeP2S12 is investigated in detail by combining in/ex-situ Raman spectra and Electrochemical Impedance Spectroscopy(EIS).It can be determined that chemical side reaction between LiNi0.8Co0.15Al0.05O2 and Li10GeP2S12 will occur immediately once contacted,and the interfacial deterioration becomes more serious after charge-discharge process under the dual effects of chemical and electrochemical side reactions.Moreover,our research reveals that the interfacial stability and the cycle performance of ASSLB can be greatly enhanced by increasing Al-substitution for Ni in LiNi0.85-xCo0.15AlxO2.In particular,the capacity retention of LiNi0.6Co0.15Al0.25O2 cathode after 200 cycles can reach 81.9%,much higher than that of LiNi0.8Co0.15Al0.05O2 cathode(12.5%@200 cycles).This work gives an insight to study the interfacial issues between Ni-rich layered oxide cathode and sulfide electrolyte for ASSLBs.
基金This work was supported by the National Natural Science Foundation of China(Nos.61125503,61235009,and 61801520)the Foundation for Development of Science and Technology of Shanghai(No.13]C1408300)+1 种基金the Natural Science Foundation of Hunan Province(Nos.2019JJ50756 and 2018JJ3521)the Scientific Research Project of Hunan Province Education Department(No.20B144).
文摘When two synchronized laser beams illuminate the inner surface of bulk lithium niobate crystals with magnesium doping(5%/mol MgO:LiNbO_(3))under the condition of total reflection,semi-degenerate four-wave mixing(FWM)is generated.On this basis,a more sophisticated frequency conversion process on the interface of nonlinear crystal has been researched.The generation mechanism of FWM is associated with the fundamental waves reflected on the inner surface of the nonlinear crystal.Analysis of the phase-matching mechanism confirms that the FWM is radiated by the third-order nonlinear polarized waves,which are stimulated by the third-order nonlinear susceptibility coefficient of the nonlinear crystal.Theoretically calculated and experimentally measured corresponding data have been presented in this article.These results are expected to provide new inspiration for further experimental and theoretical research on frequency conversion in nonlinear crystals.
