A modified cellular automaton model is developed to depict the interface evolution inside the cementite plus ferrite lamellar microstructures during the reaustenitization of a pearlite steel. In this model, migrations...A modified cellular automaton model is developed to depict the interface evolution inside the cementite plus ferrite lamellar microstructures during the reaustenitization of a pearlite steel. In this model, migrations of both the austenite- ferrite and austenite-cementite interfaces coupled with the carbon diffusion and redistribution are integrated. The capil- laxity effect derived from local interface curvatures is also carefully considered by involving the concentration given by the phase diagram modified by the Gibbs-Thomson effect. This allows the interface evolution from a transient state to a steady state under different annealing conditions and various interlamellar spacings to be simulated. The proposed cellular automaton approach could be readily used to describe the kinetics of austenite formation from the lamellar pearlites and virtually reveal the kinematics of the moving interfaces from the microstructural aspect.展开更多
This review summarizes the work carried out in the field of interface study in carbon nanotube reinforced aluminum （CNT/A1） composites. Much research work has been conducted to reveal the evolution of CNT/A1 interfa...This review summarizes the work carried out in the field of interface study in carbon nanotube reinforced aluminum （CNT/A1） composites. Much research work has been conducted to reveal the evolution of CNT/A1 interface in producing the composite with the purpose of achieving uniform distribution of CNTs and tight interfacial bonding. The effect and principles of coating were reviewed along with the illustration of ＂intermetallic interphases＂ design. Different roles of CNT/Al interface in structural and functional application were elucidated, and the future work that needs attention was addressed.展开更多
Garnet-type solid-state electrolytes(SSEs)are particularly attractive in the construction of all-solid-state lithium(Li)batteries due to their high ionic conductivity,wide electrochemical window and remarkable(electro...Garnet-type solid-state electrolytes(SSEs)are particularly attractive in the construction of all-solid-state lithium(Li)batteries due to their high ionic conductivity,wide electrochemical window and remarkable(electro)chemical stability.However,the intractable issues of poor cathode/garnet interface and general low cathode loading hinder their practical application.Herein,we demonstrate the construction of a reinforced cathode/garnet interface by spark plasma sintering,via co-sintering Li_(6.5)La_(3)Zr_(1.5)Ta_(0.5)O_(12)(LLZTO)electrolyte powder and LiCoO_(2)/LLZTO composite cathode powder directly into a dense dual-layer with 5 wt%Li_(3)BO_(3)as sintering additive.The bulk composite cathode with LiCoO_(2)/LLZTO cross-linked structure is firmly welded to the LLZTO layer,which optimizes both Li-ion and electron transport.Therefore,the one-step integrated sintering process implements an ultra-low cathode/garnet interfacial resistance of 3.9Ωcm^(2)(100◦C)and a high cathode loading up to 2.02 mAh cm^(−2).Moreover,the Li_(3)BO_(3)reinforced LiCoO_(2)/LLZTO interface also effectively mitigates the strain/stress of LiCoO_(2),which facilitates the achieving of superior cycling stability.The bulk-type Li|LLZTO|LiCoO_(2)-LLZTO full cell with areal capacity of 0.73 mAh cm^(−2)delivers capacity retention of 81.7%after 50 cycles at 100μA cm^(−2).Furthermore,we reveal that non-uniform Li plating/stripping leads to the formation of gaps and finally results in the separation of Li and LLZTO electrolyte during long-term cycling,which becomes the dominant capacity decay mechanism in high-capacity full cells.This work provides insight into the degradation of Li/SSE interface and a strategy to radically improve the electrochemical performance of garnet-based all-solid-state Li batteries.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos. 51371169 and 51401214)
文摘A modified cellular automaton model is developed to depict the interface evolution inside the cementite plus ferrite lamellar microstructures during the reaustenitization of a pearlite steel. In this model, migrations of both the austenite- ferrite and austenite-cementite interfaces coupled with the carbon diffusion and redistribution are integrated. The capil- laxity effect derived from local interface curvatures is also carefully considered by involving the concentration given by the phase diagram modified by the Gibbs-Thomson effect. This allows the interface evolution from a transient state to a steady state under different annealing conditions and various interlamellar spacings to be simulated. The proposed cellular automaton approach could be readily used to describe the kinetics of austenite formation from the lamellar pearlites and virtually reveal the kinematics of the moving interfaces from the microstructural aspect.
基金financially supported by the National Basic Research Program of China (No.2012CB619600)the National Natural Science Foundation of China (Nos.51131004,51071100,and 51001071)+1 种基金the National High Technology Research and Development Program of China (No.2012AA030311)Shanghai Science & Technology Committee (Nos.11JC1405500)
文摘This review summarizes the work carried out in the field of interface study in carbon nanotube reinforced aluminum （CNT/A1） composites. Much research work has been conducted to reveal the evolution of CNT/A1 interface in producing the composite with the purpose of achieving uniform distribution of CNTs and tight interfacial bonding. The effect and principles of coating were reviewed along with the illustration of ＂intermetallic interphases＂ design. Different roles of CNT/Al interface in structural and functional application were elucidated, and the future work that needs attention was addressed.
基金This work was supported by the National Key R&D Program of China(Grant No.2021YFB2401800)the National Natural Science Foundation of China(Grants Nos.21875196,22279108,21935009 and 22021001)the Fundamental Research Funds for Xiamen University(No.20720202019).
文摘Garnet-type solid-state electrolytes(SSEs)are particularly attractive in the construction of all-solid-state lithium(Li)batteries due to their high ionic conductivity,wide electrochemical window and remarkable(electro)chemical stability.However,the intractable issues of poor cathode/garnet interface and general low cathode loading hinder their practical application.Herein,we demonstrate the construction of a reinforced cathode/garnet interface by spark plasma sintering,via co-sintering Li_(6.5)La_(3)Zr_(1.5)Ta_(0.5)O_(12)(LLZTO)electrolyte powder and LiCoO_(2)/LLZTO composite cathode powder directly into a dense dual-layer with 5 wt%Li_(3)BO_(3)as sintering additive.The bulk composite cathode with LiCoO_(2)/LLZTO cross-linked structure is firmly welded to the LLZTO layer,which optimizes both Li-ion and electron transport.Therefore,the one-step integrated sintering process implements an ultra-low cathode/garnet interfacial resistance of 3.9Ωcm^(2)(100◦C)and a high cathode loading up to 2.02 mAh cm^(−2).Moreover,the Li_(3)BO_(3)reinforced LiCoO_(2)/LLZTO interface also effectively mitigates the strain/stress of LiCoO_(2),which facilitates the achieving of superior cycling stability.The bulk-type Li|LLZTO|LiCoO_(2)-LLZTO full cell with areal capacity of 0.73 mAh cm^(−2)delivers capacity retention of 81.7%after 50 cycles at 100μA cm^(−2).Furthermore,we reveal that non-uniform Li plating/stripping leads to the formation of gaps and finally results in the separation of Li and LLZTO electrolyte during long-term cycling,which becomes the dominant capacity decay mechanism in high-capacity full cells.This work provides insight into the degradation of Li/SSE interface and a strategy to radically improve the electrochemical performance of garnet-based all-solid-state Li batteries.
