Shock compression and spallation damage of a face-center cubic phase high-entropy alloy(HEA)Al_(0.1)CoCrFeNi were investigated via plate impact experiments along with free surface velocity measurements.Postmortem samp...Shock compression and spallation damage of a face-center cubic phase high-entropy alloy(HEA)Al_(0.1)CoCrFeNi were investigated via plate impact experiments along with free surface velocity measurements.Postmortem samples were characterized with transmission electron microscopy and electron backscatter diffraction.The Hugoniot equation of state and spall strength at different impact strengths were determined.There exists a power-law relation between spall strength and strain rate.The spall strength of Al_(0.1)CoCrFeNi HEA is about 50%higher than those of previously studied HEAs and comparable to those widely applied structural stainless steels at the same shock stress.Dislocation glide and stacking faults are the important deformation mechanisms in the Al_(0.1)CoCrFeNi HEA.Nanotwins are only observed at high shock stress.Damage in the Al_(0.1)CoCrFeNi HEA is ductile in nature.Voids are nucleated preferentially in grain interiors,and the intragranular voids show a strong dependence on grain boundary misorientation and peak stress.展开更多
Affected by cobalt(Co)supply bottlenecks and high costs,Co-free Ni-rich layered cathodes are considered the most promising option for economical and sustainable development of lithium-ion batteries(LIBs).Low-cost LiNi...Affected by cobalt(Co)supply bottlenecks and high costs,Co-free Ni-rich layered cathodes are considered the most promising option for economical and sustainable development of lithium-ion batteries(LIBs).Low-cost LiNi_(x)Al_(1-x)O_(2)(x≥0.9)cathode are rarely reported due to their chemo-mechanical instabilities and poor cycle life.Herein,we employ a strategy of Mg/W Li/Ni dualsite co-doping LiNi_(0.9)Al_(0.1)O_(2)(named as LNA90)cathodes to enhance cycling stability by modifying the crystal structure and forming a center radially aligned microstructure.The Mg/W co-doped LiNi_(0.9)Al_(0.1)O_(2)cathode(named as LNAMW)exhibits high capacity retention of 94.9%at 1 C and 3.0-4.5 V after 100 cycles with 22.0%increase over the pristine cathode LNA90 and maintains the intact particle morphology.Meanwhile,the cycling performance of LNAMW cathode exceeds that of most reported Ni-rich cathodes(Ni mol%>80%).Our work offers a straightforward,efficient,and scalable strategy for the future design of Cofree Ni-rich cathodes to facilitate the development of economical lithium-ion batteries.展开更多
基金financially supported in part by the Sichuan Province Key R&D Program(No.2022YFG0033)the National Natural Science Foundation of China(Nos.11627901 and11902274)。
文摘Shock compression and spallation damage of a face-center cubic phase high-entropy alloy(HEA)Al_(0.1)CoCrFeNi were investigated via plate impact experiments along with free surface velocity measurements.Postmortem samples were characterized with transmission electron microscopy and electron backscatter diffraction.The Hugoniot equation of state and spall strength at different impact strengths were determined.There exists a power-law relation between spall strength and strain rate.The spall strength of Al_(0.1)CoCrFeNi HEA is about 50%higher than those of previously studied HEAs and comparable to those widely applied structural stainless steels at the same shock stress.Dislocation glide and stacking faults are the important deformation mechanisms in the Al_(0.1)CoCrFeNi HEA.Nanotwins are only observed at high shock stress.Damage in the Al_(0.1)CoCrFeNi HEA is ductile in nature.Voids are nucleated preferentially in grain interiors,and the intragranular voids show a strong dependence on grain boundary misorientation and peak stress.
基金The National Natural Science Foundation of China(No.52004116)the Major Science and Technology Special Program of Yunnan Province(No.202202AG050003)+2 种基金the Applied Basic Research Plan of Yunnan Province(Nos.202101AS070020,202201AT070184,202101BE070001-016,and 202001AU070039)the High-level Talent Introduction Scientific Research Start Project of KUST(No.20190015)the analysis and testing fund of Kunming University of Technology(No.2021M20202202144)are gratefully acknowledged.
文摘Affected by cobalt(Co)supply bottlenecks and high costs,Co-free Ni-rich layered cathodes are considered the most promising option for economical and sustainable development of lithium-ion batteries(LIBs).Low-cost LiNi_(x)Al_(1-x)O_(2)(x≥0.9)cathode are rarely reported due to their chemo-mechanical instabilities and poor cycle life.Herein,we employ a strategy of Mg/W Li/Ni dualsite co-doping LiNi_(0.9)Al_(0.1)O_(2)(named as LNA90)cathodes to enhance cycling stability by modifying the crystal structure and forming a center radially aligned microstructure.The Mg/W co-doped LiNi_(0.9)Al_(0.1)O_(2)cathode(named as LNAMW)exhibits high capacity retention of 94.9%at 1 C and 3.0-4.5 V after 100 cycles with 22.0%increase over the pristine cathode LNA90 and maintains the intact particle morphology.Meanwhile,the cycling performance of LNAMW cathode exceeds that of most reported Ni-rich cathodes(Ni mol%>80%).Our work offers a straightforward,efficient,and scalable strategy for the future design of Cofree Ni-rich cathodes to facilitate the development of economical lithium-ion batteries.
