Solid-state batteries based on Li and nonflammable solid-state electrolytes(SSEs)have aroused the attention of numerous researchers because of their absolute safety and potentially high energy density.Most SSEs after ...Solid-state batteries based on Li and nonflammable solid-state electrolytes(SSEs)have aroused the attention of numerous researchers because of their absolute safety and potentially high energy density.Most SSEs after coming into contact with Li are reduced,which leads to high interfacial charge-transfer impedance and dendrites formation.In this study,an“interlayer-Li pre-reduction strategy”was proposed to solve the above problem of reduction.An intermediate layer was introduced between solid electrolyte and Li,and it reacted with Li to produce a stable and ion-conductive interphase.Cubic garnet-type Nb-doped Li_(7)La_(3)Zr_(2)O_(12)(Nb-LLZO)was selected as an example solid electrolyte since it is characterized by high ionic conductivity,feasible preparation under ambient conditions,as well as low cost.The high impedance arising from the reduction at the Nb-LLZO|Li interface has limited its application.In this paper,a nano-scale Li phosphorus oxynitride(LiPON)layer was deposited on the Nb-LLZO pellets through radio frequency(RF)magnetron sputtering,which pre-reacted with Li in-situ to produce a lithiophilic,electronically insulating,and ionic conductive interphase.The produced interphase significantly inhibited the reduction of Nb5+against Li and the formation and propagation of Li dendrites.It is noteworthy that Li|LiPON|Nb-LLZO|LiPON|Li cells stably cycled for over 2,000 h without any short circuit.This study emphasizes and demonstrates the significance of the pre-conversion of modification layer between unstable SSE and Li metal to improve interfacial stability.展开更多
This paper proposes a modified proportional-integral(PI)controller and compares it with a proportional-resonant(PR)controller.These controllers are tested on a three-phase direct matrix converter(MC).The modified PI c...This paper proposes a modified proportional-integral(PI)controller and compares it with a proportional-resonant(PR)controller.These controllers are tested on a three-phase direct matrix converter(MC).The modified PI controller involves current feedforward together with space vector modulation(SVM)to control the MC output currents.This controller provides extra control flexibility in terms of the current error reduction,and it gives improved steady-state tracking performance.When the coefficient of current feedforward is equal to the load resistor(K=R),the steady-state error is effectively minimized even when regulating sinusoidal variables.The total harmonic distortion is also reduced.In order to comparatively evaluate the modified PI controller,a PR controller is designed and tested.Both the modified PI and PR controllers are implemented in the natural frame(abc)in a straightforward manner.This removes the coordinate transformations that are required in the stationary(αβ)and synchronous(dq)reference frame based control strategies.In addition,both controllers can handle the unbalanced conditions.The experimental and simulation results verify the feasibility and effectiveness of the proposed controllers.展开更多
In this paper, the frequency conversion of quantum states based on the intracavity nonlinear interaction is proposed. The fidelity of an input state after frequency conversion is calculated, and it is shown the noise-...In this paper, the frequency conversion of quantum states based on the intracavity nonlinear interaction is proposed. The fidelity of an input state after frequency conversion is calculated, and it is shown the noise-free frequency conversion of a quantum state can be achieved by injecting a strong signal field. The dependences of conversion efficiency on the pump parameter, extra losses and input state amplitude are also analysed.展开更多
In the present paper, we investigate the linear instability and adiabaticity of a dark state during conversion of two species of fermionic atoms to stable molecules through the stimulated Raman adiabatic passage aided...In the present paper, we investigate the linear instability and adiabaticity of a dark state during conversion of two species of fermionic atoms to stable molecules through the stimulated Raman adiabatic passage aided by Feshbach resonance. We analytically obtain the regions for the appearance of linear instability. Moreover, taking 40K and 6Li atom molecule conversion systems as examples, we give the unstable regions numerically. We also attempt to obtain the adiabatic criterion for this nonlinear system with classical adiabatic dynamics and study the adibaticity of the dark state with the adiabatic condition.展开更多
In the present paper, we investigate the instability, adiabaticity, and controlling effects of external fields for a dark state in a homonuclear atom-tetramer conversion that is implemented by a generalized stimulated...In the present paper, we investigate the instability, adiabaticity, and controlling effects of external fields for a dark state in a homonuclear atom-tetramer conversion that is implemented by a generalized stimulated Raman adiabatic passage. We analytically obtain the regions for the appearance of dynamical instability and study the adiabatic evolution by a newly defined adiabatic fidelity. Moreover, the effects of the external field parameters and the spontaneous emissions on the conversion efficiency are also investigated.展开更多
Phosphorus is the potential anode material for emerging potassium-ion batteries(PIBs)owing to the highest specific capacity and relatively low operation plateau.However,the reversible delivered capacities of phosphoru...Phosphorus is the potential anode material for emerging potassium-ion batteries(PIBs)owing to the highest specific capacity and relatively low operation plateau.However,the reversible delivered capacities of phosphorus-based anodes,in reality,are far from the theoretical capacity corresponding to the formation of K3P alloy.And,their underlying potassium storage mechanisms remain poorly understood.To address this issue,for the first time,we perform high-resolution solid-state31P NMR combined with XRD measurements,and density functional theory calculations to yield a systemic quantitative understanding of(de)potassiation reaction mechanism of phosphorus anode.We explicitly reveal a previously unknown asymmetrical nanocrystalline-to-amorphous transition process via rP←→(K_(3)P_(11),K_(3)P_(7),beta-K_(4)P_(6))←→(alpha-K4P6)←→(K_(1-x)P,KP,K_(4-x)P3,K_(1+x)P)←→(amorphous K4P3,amorphous K3P)that are proceed along with the electrochemical potassiation/depotassiation processes.Additionally,the corresponding KP alloys intermediates,such as the amorphous phases of K_(4)P_(3),K_(3)P,and the nonstoichiometric phases of“K_(1-x)P”,“K_(1+x)P”,“K_(4-x)P_(3)”are experimentally detected,which indicating various complicated K-P alloy species are coexisted and evolved with the sluggish electrochemical reaction kinetics,resulting in lower capacity of phosphorus-based anodes.Our findings offer some insights into the specific multi-phase evolution mechanism of alloying anodes that may be generally involved in conversion-type electrode materials for PIBs.展开更多
基金the National Key Research and Development Program of China(No.2018YFE0181300)the National Natural Science Foundation of China(No.21805055)+3 种基金the Guangdong Natural Science Funds(No.2019A1515010675)the Guangxi Natural Science Funds(No.2019JJA120043)the Department of Science and Technology of Guangxi Province(No.2021AB17045)the Science and Technology Project of Shenzhen(Nos.JCYJ20210324094206019 and JCYJ20190808142209376).
文摘Solid-state batteries based on Li and nonflammable solid-state electrolytes(SSEs)have aroused the attention of numerous researchers because of their absolute safety and potentially high energy density.Most SSEs after coming into contact with Li are reduced,which leads to high interfacial charge-transfer impedance and dendrites formation.In this study,an“interlayer-Li pre-reduction strategy”was proposed to solve the above problem of reduction.An intermediate layer was introduced between solid electrolyte and Li,and it reacted with Li to produce a stable and ion-conductive interphase.Cubic garnet-type Nb-doped Li_(7)La_(3)Zr_(2)O_(12)(Nb-LLZO)was selected as an example solid electrolyte since it is characterized by high ionic conductivity,feasible preparation under ambient conditions,as well as low cost.The high impedance arising from the reduction at the Nb-LLZO|Li interface has limited its application.In this paper,a nano-scale Li phosphorus oxynitride(LiPON)layer was deposited on the Nb-LLZO pellets through radio frequency(RF)magnetron sputtering,which pre-reacted with Li in-situ to produce a lithiophilic,electronically insulating,and ionic conductive interphase.The produced interphase significantly inhibited the reduction of Nb5+against Li and the formation and propagation of Li dendrites.It is noteworthy that Li|LiPON|Nb-LLZO|LiPON|Li cells stably cycled for over 2,000 h without any short circuit.This study emphasizes and demonstrates the significance of the pre-conversion of modification layer between unstable SSE and Li metal to improve interfacial stability.
文摘This paper proposes a modified proportional-integral(PI)controller and compares it with a proportional-resonant(PR)controller.These controllers are tested on a three-phase direct matrix converter(MC).The modified PI controller involves current feedforward together with space vector modulation(SVM)to control the MC output currents.This controller provides extra control flexibility in terms of the current error reduction,and it gives improved steady-state tracking performance.When the coefficient of current feedforward is equal to the load resistor(K=R),the steady-state error is effectively minimized even when regulating sinusoidal variables.The total harmonic distortion is also reduced.In order to comparatively evaluate the modified PI controller,a PR controller is designed and tested.Both the modified PI and PR controllers are implemented in the natural frame(abc)in a straightforward manner.This removes the coordinate transformations that are required in the stationary(αβ)and synchronous(dq)reference frame based control strategies.In addition,both controllers can handle the unbalanced conditions.The experimental and simulation results verify the feasibility and effectiveness of the proposed controllers.
基金supported by the National Natural Science Foundation of China (Grant No. 10974126)the National Basic Research Program of China (Grant No. 2010CB923102)
文摘In this paper, the frequency conversion of quantum states based on the intracavity nonlinear interaction is proposed. The fidelity of an input state after frequency conversion is calculated, and it is shown the noise-free frequency conversion of a quantum state can be achieved by injecting a strong signal field. The dependences of conversion efficiency on the pump parameter, extra losses and input state amplitude are also analysed.
基金supported by the National Natural Science Foundation of China (Grants No. 11005055, 10725521, and 11075020)the National Fundamental Research of China (Grant No. 2011CB921503)+2 种基金the Ph. D. Program Foundation of the Science and Technology Bureau of Liaoning Province of China (Grant No. 20111034)the Higher School Excellent Researcher Award Program from the the Educational Department of Liaoning Province of China (Grant No. LJQ2011005)the Youth Fund Project of Liaoning University (Grant No. 2010LDQN17)
文摘In the present paper, we investigate the linear instability and adiabaticity of a dark state during conversion of two species of fermionic atoms to stable molecules through the stimulated Raman adiabatic passage aided by Feshbach resonance. We analytically obtain the regions for the appearance of linear instability. Moreover, taking 40K and 6Li atom molecule conversion systems as examples, we give the unstable regions numerically. We also attempt to obtain the adiabatic criterion for this nonlinear system with classical adiabatic dynamics and study the adibaticity of the dark state with the adiabatic condition.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11005055,11075020,and 11204117)the National Fundamental Research Programme of China(Grant No.2011CB921503)+1 种基金the Ph.D.Programs Foundation of Liaoning Provincial Science and Technology Bureau(GrantNo.201103778)the Higher School Excellent Researcher Award Program from the Educational Department of Liaoning Province of China(GrantNo.LJQ2011005)
文摘In the present paper, we investigate the instability, adiabaticity, and controlling effects of external fields for a dark state in a homonuclear atom-tetramer conversion that is implemented by a generalized stimulated Raman adiabatic passage. We analytically obtain the regions for the appearance of dynamical instability and study the adiabatic evolution by a newly defined adiabatic fidelity. Moreover, the effects of the external field parameters and the spontaneous emissions on the conversion efficiency are also investigated.
基金financially supported by National Nature Science Foundation of China(Grant No.22272175,21805278,52072323,52122211)the Fujian Science and Technology Planning Projects of China(2020T3022,2022T3067)+3 种基金the National Key R&D Program of China(No.2021YFB3500400)the Future-prospective and Stride-across Programs of Haixi Institutes,Chinese Academy of Sciences(No.CXZX-2022-GH02)the Youth Innovation Foundation of Xiamen City(Grant No.3502Z20206083)the Opening Project of PCOSS,Xiamen University(Grant No.202014)。
文摘Phosphorus is the potential anode material for emerging potassium-ion batteries(PIBs)owing to the highest specific capacity and relatively low operation plateau.However,the reversible delivered capacities of phosphorus-based anodes,in reality,are far from the theoretical capacity corresponding to the formation of K3P alloy.And,their underlying potassium storage mechanisms remain poorly understood.To address this issue,for the first time,we perform high-resolution solid-state31P NMR combined with XRD measurements,and density functional theory calculations to yield a systemic quantitative understanding of(de)potassiation reaction mechanism of phosphorus anode.We explicitly reveal a previously unknown asymmetrical nanocrystalline-to-amorphous transition process via rP←→(K_(3)P_(11),K_(3)P_(7),beta-K_(4)P_(6))←→(alpha-K4P6)←→(K_(1-x)P,KP,K_(4-x)P3,K_(1+x)P)←→(amorphous K4P3,amorphous K3P)that are proceed along with the electrochemical potassiation/depotassiation processes.Additionally,the corresponding KP alloys intermediates,such as the amorphous phases of K_(4)P_(3),K_(3)P,and the nonstoichiometric phases of“K_(1-x)P”,“K_(1+x)P”,“K_(4-x)P_(3)”are experimentally detected,which indicating various complicated K-P alloy species are coexisted and evolved with the sluggish electrochemical reaction kinetics,resulting in lower capacity of phosphorus-based anodes.Our findings offer some insights into the specific multi-phase evolution mechanism of alloying anodes that may be generally involved in conversion-type electrode materials for PIBs.
