Nucleation of lithium sulfide(Li_(2)S)induced by electrocatalysts plays a crucial role in mitigating the shut-tle effect.However,short-chain polysulfides on electrocatalysts surfaces tend to re-dissolve into elec-trol...Nucleation of lithium sulfide(Li_(2)S)induced by electrocatalysts plays a crucial role in mitigating the shut-tle effect.However,short-chain polysulfides on electrocatalysts surfaces tend to re-dissolve into elec-trolytes,delaying Li_(2)S supersaturation and its nucleation.In this study,we draw inspiration from the ribosome-driven protein synthesis process in cells to prepare ultrasmall nitrogen-doped MoS_(2) nanocrys-tals anchored on porous nitrogen-doped carbon networks(N-MoS_(2)-NC)electrocatalysts.Excitedly,the ex-situ SEM demonstrates that ribosome-inspired N-MoS_(2)-NC electrocatalysts induce early nucleation and rapid growth of three-dimensional Li_(2)s during discharge.Theoretical calculations reveal that the Li-s bond length in N-MoS_(2)-Li_(2)S(100)is shorter,and the corresponding interfacial formation energy is lower than in MoS_(2)-Li_(2)S(100).This accelerated conversion of lithium polysulfides to Li_(2)S can enhance the utilization of active substances and inhibit the shuttle effect.This study highlights the potential of ribosome-inspired N-MoS_(2)-NC in improving the electrochemical stability of Li-S batteries,providing valuable insights for future electrocatalyst design.展开更多
Lithium metal is the ultimate anode choice for high energy rechargeable lithium batteries owing to its ultra-high theoretical capacity,however,Li dendrites and low Coulombic efficiency(CE)caused by disordered Li plati...Lithium metal is the ultimate anode choice for high energy rechargeable lithium batteries owing to its ultra-high theoretical capacity,however,Li dendrites and low Coulombic efficiency(CE)caused by disordered Li plating restrict its practical application.Herein,we develop an ultrathin Sn-decorated Cu substrate(Sn@Cu)fabricated by an electroless plating method to induce ordered Li nucleation and growth behavior.The lithiophilic Sn interfacial layer is found to play a critical role to lower the Li nucleation over-potential and promote fast Li-migration kinetics,and the underlying mechanism is revealed using the first principle calculations.Accordingly,a dense dendrite-free and Li deposition with large granular morphology is obtained,which significantly improved the CE and cycling performance of Li‖Sn@Cu half cells symmetric cells.Symmetric cells using the Li-Sn@Cu electrode display a much-prolonged life span(>1200 h)with low overpotential(~18 mV)at a high current density of 1 mA cm^(-2).Moreover,full cells paired with commercial LiFePO_(4) cathode(1.8 mAh cm^(-2))deliver enhanced cycling stability(0.5 C,300 cycles)and excellent rate performance.This work provides a simple and effective way to bring about high efficiency and long lifespan substrates for practical applications.展开更多
In nuclear structural materials, the nuclear irradiations induce the precipitations of soluble elements or produce the insoluble elements such as He atoms that may form clusters, heavily shortening the service life-ti...In nuclear structural materials, the nuclear irradiations induce the precipitations of soluble elements or produce the insoluble elements such as He atoms that may form clusters, heavily shortening the service life-times of the materials. In the present work, a diffusion model is developed to predict where and how fast the solute atoms （either soluble or insoluble） aggregate, and this model is applied to the study of the formation and growth of He bubbles in metal tritides （PdT0.6, ErT2, NbT0.0225, VT0.5, TaT0.097, TiT1.5, ZrT1.6） within one thousand days. The results are in good agreement with the available experimental observations and suggest that searching for metals with a barrier of more than 1.1 eV for a single He atom diffusion and making more defects in metal tritides can significantly reduce the growth of He bubbles and extend the service time of the metals.展开更多
Porous three-dimensional (3D) structures generally improve the performance of electrodes by increasing their active surface area and the diffusion speed of electrolyte ions during charging/discharging.Threedimensional...Porous three-dimensional (3D) structures generally improve the performance of electrodes by increasing their active surface area and the diffusion speed of electrolyte ions during charging/discharging.Threedimensional polypyrrole (PPy) based films were created by electrodepositing PPy in the presence of varying amounts of chloride anions (Cl^(-)) and polyanionic ribbonlike nanoparticles (carboxylated cellulose nanocrystals (CNC-COO-)) as scaffold material.The assembly mechanism of the 3D PPy electrodes combines the effect of different nucleation and growth mechanisms during electropolymerization and deposition of the formed PPy with CNC-COO-and with Cl^(-).The highest area capacitance of these electrode materials was 1.39 F cm^(-2)(150.2 F g^(-1)) at a current density of 1 m A cm^(-2)(0.1 A g^(-1)).More importantly,at a high current density of 20 m A cm^(-2)(2.2 A g^(-1)),the thick (ca.130μm),3D,and high mass loading(9.2 mg cm^(-2)) Cl^(-):CNC-COO-/PPy films exhibited an excellent areal capacitance of 0.85 F cm^(-2)(70.8 F g^(-1)),increasing about 16%over CNC-COO-/PPy films prepared without Cl^(-)present during electrodeposition.In addition,an aqueous Cl^(-):CNC-COO-/PPy (with Cl^(-):CNC-COO-=2.0) symmetric supercapacitor had an outstanding energy density of 41.15μWh cm^(-2)(4.46 Wh kg^(-1)) and excellent cycling stability,while even improving on its original areal capacitance (to 111.2%of its original capacitance) after cycling3000 cycles at 8 m A cm^(-2),indicating their potential in energy storage devices.展开更多
基金support from the National Natural Science Foundation of China(Grant Nos.52372083,52173255),the Collaborative Innovation Center for Advanced Micro/nanomaterials and Equipment(Co-constructed by Jiangsu Province and Ministry of Education)support from the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20230538).
文摘Nucleation of lithium sulfide(Li_(2)S)induced by electrocatalysts plays a crucial role in mitigating the shut-tle effect.However,short-chain polysulfides on electrocatalysts surfaces tend to re-dissolve into elec-trolytes,delaying Li_(2)S supersaturation and its nucleation.In this study,we draw inspiration from the ribosome-driven protein synthesis process in cells to prepare ultrasmall nitrogen-doped MoS_(2) nanocrys-tals anchored on porous nitrogen-doped carbon networks(N-MoS_(2)-NC)electrocatalysts.Excitedly,the ex-situ SEM demonstrates that ribosome-inspired N-MoS_(2)-NC electrocatalysts induce early nucleation and rapid growth of three-dimensional Li_(2)s during discharge.Theoretical calculations reveal that the Li-s bond length in N-MoS_(2)-Li_(2)S(100)is shorter,and the corresponding interfacial formation energy is lower than in MoS_(2)-Li_(2)S(100).This accelerated conversion of lithium polysulfides to Li_(2)S can enhance the utilization of active substances and inhibit the shuttle effect.This study highlights the potential of ribosome-inspired N-MoS_(2)-NC in improving the electrochemical stability of Li-S batteries,providing valuable insights for future electrocatalyst design.
基金financially supported by the National Natural Science Foundation of China(22075216,21773177)the Fundamental Research Funds for Central University(2042021kf0194)。
文摘Lithium metal is the ultimate anode choice for high energy rechargeable lithium batteries owing to its ultra-high theoretical capacity,however,Li dendrites and low Coulombic efficiency(CE)caused by disordered Li plating restrict its practical application.Herein,we develop an ultrathin Sn-decorated Cu substrate(Sn@Cu)fabricated by an electroless plating method to induce ordered Li nucleation and growth behavior.The lithiophilic Sn interfacial layer is found to play a critical role to lower the Li nucleation over-potential and promote fast Li-migration kinetics,and the underlying mechanism is revealed using the first principle calculations.Accordingly,a dense dendrite-free and Li deposition with large granular morphology is obtained,which significantly improved the CE and cycling performance of Li‖Sn@Cu half cells symmetric cells.Symmetric cells using the Li-Sn@Cu electrode display a much-prolonged life span(>1200 h)with low overpotential(~18 mV)at a high current density of 1 mA cm^(-2).Moreover,full cells paired with commercial LiFePO_(4) cathode(1.8 mAh cm^(-2))deliver enhanced cycling stability(0.5 C,300 cycles)and excellent rate performance.This work provides a simple and effective way to bring about high efficiency and long lifespan substrates for practical applications.
基金Project supported by the Specialized Research Fund for the Doctoral Program of Higher Education,China(Grant No.20130071110018)the National Natural Science Foundation of China(Grant No.11274073)
文摘In nuclear structural materials, the nuclear irradiations induce the precipitations of soluble elements or produce the insoluble elements such as He atoms that may form clusters, heavily shortening the service life-times of the materials. In the present work, a diffusion model is developed to predict where and how fast the solute atoms （either soluble or insoluble） aggregate, and this model is applied to the study of the formation and growth of He bubbles in metal tritides （PdT0.6, ErT2, NbT0.0225, VT0.5, TaT0.097, TiT1.5, ZrT1.6） within one thousand days. The results are in good agreement with the available experimental observations and suggest that searching for metals with a barrier of more than 1.1 eV for a single He atom diffusion and making more defects in metal tritides can significantly reduce the growth of He bubbles and extend the service time of the metals.
基金supported by the Research Foundation Flanders,Belgium(3E181170 and 12Y0319N)supported by the China Scholarship Council,China(CSC,201806220066)。
文摘Porous three-dimensional (3D) structures generally improve the performance of electrodes by increasing their active surface area and the diffusion speed of electrolyte ions during charging/discharging.Threedimensional polypyrrole (PPy) based films were created by electrodepositing PPy in the presence of varying amounts of chloride anions (Cl^(-)) and polyanionic ribbonlike nanoparticles (carboxylated cellulose nanocrystals (CNC-COO-)) as scaffold material.The assembly mechanism of the 3D PPy electrodes combines the effect of different nucleation and growth mechanisms during electropolymerization and deposition of the formed PPy with CNC-COO-and with Cl^(-).The highest area capacitance of these electrode materials was 1.39 F cm^(-2)(150.2 F g^(-1)) at a current density of 1 m A cm^(-2)(0.1 A g^(-1)).More importantly,at a high current density of 20 m A cm^(-2)(2.2 A g^(-1)),the thick (ca.130μm),3D,and high mass loading(9.2 mg cm^(-2)) Cl^(-):CNC-COO-/PPy films exhibited an excellent areal capacitance of 0.85 F cm^(-2)(70.8 F g^(-1)),increasing about 16%over CNC-COO-/PPy films prepared without Cl^(-)present during electrodeposition.In addition,an aqueous Cl^(-):CNC-COO-/PPy (with Cl^(-):CNC-COO-=2.0) symmetric supercapacitor had an outstanding energy density of 41.15μWh cm^(-2)(4.46 Wh kg^(-1)) and excellent cycling stability,while even improving on its original areal capacitance (to 111.2%of its original capacitance) after cycling3000 cycles at 8 m A cm^(-2),indicating their potential in energy storage devices.
