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
Ag-doped ZnO (ZnO:Ag) films are prepared on c-plane sapphire substrates by pulsed laser deposition at different substrate temperatures.The effect of substrate temperature on the ZnO:Ag film is studied in detail by EDX...Ag-doped ZnO (ZnO:Ag) films are prepared on c-plane sapphire substrates by pulsed laser deposition at different substrate temperatures.The effect of substrate temperature on the ZnO:Ag film is studied in detail by EDX,XRD and Raman spectroscopy.The results reveal that raising the substrate temperature is beneficial for incorporating Ag into ZnO:Ag films in the range of our experimental temperatures and a number of Ag atoms incorporation into ZnO:Ag films may cause the (002) peak positions of the XRD spectra shift to a lower angle direction,but hardly affect the c-axis orientation of the films.The (002) peak shift ought to be due to the increase of lattice constant in the c-axis direction caused by the partial substitution of Zn^(2+) ions by Ag^(+) ions.In addition,a local vibrational mode (LVM) at 492cm^(-1) induced by doping Ag occurred in the Raman spectra of ali the ZnO:Ag films and its peak position hardly shifted with increasing substrate temperature.It means that the LVM can act as an indication of Ag incorporation into ZnO:Ag film.展开更多
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Supported by the National Natural Science Foundation of China under Grant Nos 60777009,50532080,and 10804014the Key Laboratory Projects of the Education Department of Liaoning Province(No 20060131)the Doctoral Project of the Ministry of Education of China under Grant Nos 20070141038 and 20070141017.
文摘Ag-doped ZnO (ZnO:Ag) films are prepared on c-plane sapphire substrates by pulsed laser deposition at different substrate temperatures.The effect of substrate temperature on the ZnO:Ag film is studied in detail by EDX,XRD and Raman spectroscopy.The results reveal that raising the substrate temperature is beneficial for incorporating Ag into ZnO:Ag films in the range of our experimental temperatures and a number of Ag atoms incorporation into ZnO:Ag films may cause the (002) peak positions of the XRD spectra shift to a lower angle direction,but hardly affect the c-axis orientation of the films.The (002) peak shift ought to be due to the increase of lattice constant in the c-axis direction caused by the partial substitution of Zn^(2+) ions by Ag^(+) ions.In addition,a local vibrational mode (LVM) at 492cm^(-1) induced by doping Ag occurred in the Raman spectra of ali the ZnO:Ag films and its peak position hardly shifted with increasing substrate temperature.It means that the LVM can act as an indication of Ag incorporation into ZnO:Ag film.
