Lithium metal is considered as the most promising anode material for the next generation of secondary batteries due to its high theoretical specific capacity and low potential.However,undesirable parasitic reactions,p...Lithium metal is considered as the most promising anode material for the next generation of secondary batteries due to its high theoretical specific capacity and low potential.However,undesirable parasitic reactions,poor cycling stability and safety concerns could be caused by uncontrolled dendrite and high reactivity of Li metal,which hinder the practical application of Li-metal anode in high-energy rechargeable Li metal batteries(LMBs).Here,a facile way is reported to stabilize Li metal anode by building high lithiophilic Mg-Li-Cu alloy.Due to the delocalization of electrons on the deposited lithium enhanced by Cu self-diffusion into Mg-Li alloy,the growth of lithium dendrites could be inhibited by Mg-Li-Cu alloy.Moreover,the parasitic reactions with electrolyte could be avoided by the Mg-Li-Cu alloy anode.It is noteworthy that the symmetric battery life of Mg-Li-Cu alloy electrodes exceeds 9000 h at 1 m A cm^(-2)and 1 m Ah cm^(-2).The full cell(LiFePO_(4)|Mg-Li-Cu)exhibits a specific capacity of 148.2 m Ah g^(-1),with a capacity retention of 96.4%,at 1 C after 500 cycles.This work not only pave the way for application of flexible alloy anode in highly stable LMBs,but also provides novel strategies for preparation and optimization of Mg alloy.展开更多
The microstructure and mechanical properties of as-cast Al−Cu−Li−Mg−Zn alloys fabricated by conventional gravity casting and centrifugal casting techniques combined with rapid solidification were investigated.Experime...The microstructure and mechanical properties of as-cast Al−Cu−Li−Mg−Zn alloys fabricated by conventional gravity casting and centrifugal casting techniques combined with rapid solidification were investigated.Experimental results demonstrated that compared with the gravity casting technique,the water-cooling centrifugal casting technique significantly reduces porosity,refinesα(Al)grains and secondary phases,modifies the morphology of secondary phases,and mitigates both macro-and micro-segregation.These improvements arise from the synergistic effects of the vigorous backflow,centrifugal field,vibration and rapid solidification.Porosity and coarse plate-like Al13Fe4/Al7Cu2Fe phase result in the fracture before the gravity-cast alloy reaches the yield point.The centrifugal-cast alloy,however,exhibits an ultra-high yield strength of 292.0 MPa and a moderate elongation of 6.1%.This high yield strength is attributed to solid solution strengthening(SSS)of 225.3 MPa,and grain boundary strengthening(GBS)of 35.7 MPa.Li contributes the most to SSS with a scaling factor of 7.9 MPa·wt.%^(-1).The elongation of the centrifugal-cast alloy can be effectively enhanced by reducing the porosity and segregation behavior,refining the microstructure and changing the morphology of secondary phases.展开更多
基金supported by Shandong Provincial Natural Science Foundation,China(ZR2022QE014)Basic Scientific Research Fund for Central Universities(202112018)Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education)。
文摘Lithium metal is considered as the most promising anode material for the next generation of secondary batteries due to its high theoretical specific capacity and low potential.However,undesirable parasitic reactions,poor cycling stability and safety concerns could be caused by uncontrolled dendrite and high reactivity of Li metal,which hinder the practical application of Li-metal anode in high-energy rechargeable Li metal batteries(LMBs).Here,a facile way is reported to stabilize Li metal anode by building high lithiophilic Mg-Li-Cu alloy.Due to the delocalization of electrons on the deposited lithium enhanced by Cu self-diffusion into Mg-Li alloy,the growth of lithium dendrites could be inhibited by Mg-Li-Cu alloy.Moreover,the parasitic reactions with electrolyte could be avoided by the Mg-Li-Cu alloy anode.It is noteworthy that the symmetric battery life of Mg-Li-Cu alloy electrodes exceeds 9000 h at 1 m A cm^(-2)and 1 m Ah cm^(-2).The full cell(LiFePO_(4)|Mg-Li-Cu)exhibits a specific capacity of 148.2 m Ah g^(-1),with a capacity retention of 96.4%,at 1 C after 500 cycles.This work not only pave the way for application of flexible alloy anode in highly stable LMBs,but also provides novel strategies for preparation and optimization of Mg alloy.
基金support from the National Science Foundation of China (No.51971249)the Natural Science Foundation of Shandong Province,China (No.ZR2020KE012)the Science and Technology Planning Project of Longkou City,China (No.2021KJJH025).
基金financially supported by the Natural Science Foundation of Ningbo,China (No.2023J053)。
文摘The microstructure and mechanical properties of as-cast Al−Cu−Li−Mg−Zn alloys fabricated by conventional gravity casting and centrifugal casting techniques combined with rapid solidification were investigated.Experimental results demonstrated that compared with the gravity casting technique,the water-cooling centrifugal casting technique significantly reduces porosity,refinesα(Al)grains and secondary phases,modifies the morphology of secondary phases,and mitigates both macro-and micro-segregation.These improvements arise from the synergistic effects of the vigorous backflow,centrifugal field,vibration and rapid solidification.Porosity and coarse plate-like Al13Fe4/Al7Cu2Fe phase result in the fracture before the gravity-cast alloy reaches the yield point.The centrifugal-cast alloy,however,exhibits an ultra-high yield strength of 292.0 MPa and a moderate elongation of 6.1%.This high yield strength is attributed to solid solution strengthening(SSS)of 225.3 MPa,and grain boundary strengthening(GBS)of 35.7 MPa.Li contributes the most to SSS with a scaling factor of 7.9 MPa·wt.%^(-1).The elongation of the centrifugal-cast alloy can be effectively enhanced by reducing the porosity and segregation behavior,refining the microstructure and changing the morphology of secondary phases.
