The effects of low-Co AB_5 type hydrogen storage alloys prepared by quenchingand annealing on the performances of MH-Ni batteries were investigated, and the characteristics ofthe low-Co AB_5 type hydrogen storage allo...The effects of low-Co AB_5 type hydrogen storage alloys prepared by quenchingand annealing on the performances of MH-Ni batteries were investigated, and the characteristics ofthe low-Co AB_5 type hydrogen storage alloys were compared with those of the high-Co AB_5 typehydrogen storage alloy as well. The results showed that the faster the cooling of the low-Cohydrogen storage alloy is, the better homogeneity of the chemical composition for the alloy and thelonger cycle life of the battery are, but the electrochemical discharge capacity and high-ratedischarge ability are reduced. The high-rate discharge ability and charge retention of MH-Nibatteries for the conventional as-cast annealed low-Co hydrogen storage alloy were superior to thosefor the rapidly quenched low-Co hydrogen storage alloy and the high-Co hydrogen storage alloy, buta little inferior in the cycle life.展开更多
The high temperature corrosion resistance of Ni-25.9Cr-13.5Al-1.2Y-0.6Si and Ni-10.2Co-12.4Cr16.0Al-0.5Y-0.2Hf alloys was assessed in sulfidation/oxidation envi-ronments. In the environment with a sulfur partial press...The high temperature corrosion resistance of Ni-25.9Cr-13.5Al-1.2Y-0.6Si and Ni-10.2Co-12.4Cr16.0Al-0.5Y-0.2Hf alloys was assessed in sulfidation/oxidation envi-ronments. In the environment with a sulfur partial pressure of 1Pa. and an oxygenpartial pressure of 10^(-19)Pa, both these alloys exhibited three distinct stages in theweight gain-time curve when tested at 700℃. In the initial stage, selective sulfidationof Cr suppressed the formation of the other metal sulfides, resulting in lower weightgains. In the transient stage, breakdown and cracking of Cr sulfides and insufficientconcentration of Cr at the outer zone led to the rapid formation of Ni sulfides anda rapid increase in weight. In the steady-state stage, corrosion was controlled by thediffusion of anions and/or cations, which led to a parabolic rate law.展开更多
LPCNi 3.55 Co 0.75 Mn 0.4 Al 0.3 hydrogen storage alloy was investigated, and the effects of thickness of its strip casting ingots(as cast) on the electrochemical performances were discussed. It was ...LPCNi 3.55 Co 0.75 Mn 0.4 Al 0.3 hydrogen storage alloy was investigated, and the effects of thickness of its strip casting ingots(as cast) on the electrochemical performances were discussed. It was found that the 0.2 C discharge capacity increased with the increase of the thickness (from 1 mm to 10 mm) of the ingots, mainly due to the enlargement of the unit cell volume; Among the thickness of the ingots in our study, 10 mm sample showed a better activation property; LPCNi 3.55 Co 0.75 Mn 0.4 Al 0.3 alloy with 10mm showed higher comprehensive properties than those with other thickness under 1C rate.展开更多
The structure and electrochemical characteristics of La_(0.7)Mg_(0.3)Ni_(2.875)Co_(0.525)Mn_(0.1)-boron composite was studied systematically.The AB_(3) type hydrogen storage alloys La_(0.7)Mg_(0.3)Ni_(2.875)Co_(0.525)...The structure and electrochemical characteristics of La_(0.7)Mg_(0.3)Ni_(2.875)Co_(0.525)Mn_(0.1)-boron composite was studied systematically.The AB_(3) type hydrogen storage alloys La_(0.7)Mg_(0.3)Ni_(2.875)Co_(0.525)Mn_(0.1) were successfully synthesized by means of inter-media alloy La_(2)Mg_(17).The alloys were composited with boron at different weight rate.From the XRD analyses,each alloy of this series is mainly composed of(La,Mg)Ni_(3) phase and the LaNi_(5) phase,and the phase abundance of each phase varies with the boron weight rate,moreover,after composition,the c and cell volumes of(La,Mg)Ni_(3) phase increase,and the LaNi_(5) phase keep the same,which indicate that the boron may enter(La,Mg)Ni_(3) phase.The electrochemical studies show that the maximum discharge capacity of the composites decreases,but the cycling life improved.And the high rate discharge ability and exchange impendence spectroscopy(EIS)of the AB_(3) alloys and its composite were also studied.展开更多
Recently,exploring appropriate anode materials for current commercial lithium-ion batteries(LIBs) with suitable operating potential and long cycle life has attracted extensive attention.Herein,a novel anode of Bi nano...Recently,exploring appropriate anode materials for current commercial lithium-ion batteries(LIBs) with suitable operating potential and long cycle life has attracted extensive attention.Herein,a novel anode of Bi nanoparticles fully encapsulated in carbon nanosphere framework with uniform yolk-shell nanostructure was prepared via a facile hydrothermal method.Due to the special structure design,this anode of yolk-shell Bi@C can effectively moderate the volume exchange,avoid the aggregation of active Bi nanoparticle and provide superior kinetic during discharge/charge process.Cycling in the voltage of 0.01-2.0 V,yolk-shell Bi@C anode exhibits outstanding Li+storage performance(a reversible capacity over 200 mAh g-1after 400 cycles at 1.25 A g-1) and excellent rate capability(a capacity of 404,347,304,275,240,199 and 163 mAh g-1 at0.05,0.1,0.25,0.5,1.0,1.8 and 3.2 A g-1,respectively).This work indicates that rational design of nanostructured anode materials is highly applicable for the next-generation LIBs.展开更多
A new preparation method of Sm2Co17 nanoflakes was investigated. Hard magnetic Sm2 Co17 nanoflakes with thickness of 20-100 nm were obtained by milling in heptane and oleic acid under a magnetic field of 1.5 T for 0.5...A new preparation method of Sm2Co17 nanoflakes was investigated. Hard magnetic Sm2 Co17 nanoflakes with thickness of 20-100 nm were obtained by milling in heptane and oleic acid under a magnetic field of 1.5 T for 0.5-20 h. It was shown that higher anisotropic magnetic properties would be induced by the flake-shape anisotropy when the prepared Sm2 Colt particles are milled with a magnetic field. The magnetic anisotropy of flakes after being aligned under the magnetic field of 1.5 T could be further enhanced, and the value of （BH）m was 128 kJ · m a Both anisotropy and properties are better than those of the nano-particles milled without a magnetic field.展开更多
文摘The effects of low-Co AB_5 type hydrogen storage alloys prepared by quenchingand annealing on the performances of MH-Ni batteries were investigated, and the characteristics ofthe low-Co AB_5 type hydrogen storage alloys were compared with those of the high-Co AB_5 typehydrogen storage alloy as well. The results showed that the faster the cooling of the low-Cohydrogen storage alloy is, the better homogeneity of the chemical composition for the alloy and thelonger cycle life of the battery are, but the electrochemical discharge capacity and high-ratedischarge ability are reduced. The high-rate discharge ability and charge retention of MH-Nibatteries for the conventional as-cast annealed low-Co hydrogen storage alloy were superior to thosefor the rapidly quenched low-Co hydrogen storage alloy and the high-Co hydrogen storage alloy, buta little inferior in the cycle life.
文摘The high temperature corrosion resistance of Ni-25.9Cr-13.5Al-1.2Y-0.6Si and Ni-10.2Co-12.4Cr16.0Al-0.5Y-0.2Hf alloys was assessed in sulfidation/oxidation envi-ronments. In the environment with a sulfur partial pressure of 1Pa. and an oxygenpartial pressure of 10^(-19)Pa, both these alloys exhibited three distinct stages in theweight gain-time curve when tested at 700℃. In the initial stage, selective sulfidationof Cr suppressed the formation of the other metal sulfides, resulting in lower weightgains. In the transient stage, breakdown and cracking of Cr sulfides and insufficientconcentration of Cr at the outer zone led to the rapid formation of Ni sulfides anda rapid increase in weight. In the steady-state stage, corrosion was controlled by thediffusion of anions and/or cations, which led to a parabolic rate law.
文摘LPCNi 3.55 Co 0.75 Mn 0.4 Al 0.3 hydrogen storage alloy was investigated, and the effects of thickness of its strip casting ingots(as cast) on the electrochemical performances were discussed. It was found that the 0.2 C discharge capacity increased with the increase of the thickness (from 1 mm to 10 mm) of the ingots, mainly due to the enlargement of the unit cell volume; Among the thickness of the ingots in our study, 10 mm sample showed a better activation property; LPCNi 3.55 Co 0.75 Mn 0.4 Al 0.3 alloy with 10mm showed higher comprehensive properties than those with other thickness under 1C rate.
基金This work was financially supported by the National Natural Science Foundation of China(No.20573058).
文摘The structure and electrochemical characteristics of La_(0.7)Mg_(0.3)Ni_(2.875)Co_(0.525)Mn_(0.1)-boron composite was studied systematically.The AB_(3) type hydrogen storage alloys La_(0.7)Mg_(0.3)Ni_(2.875)Co_(0.525)Mn_(0.1) were successfully synthesized by means of inter-media alloy La_(2)Mg_(17).The alloys were composited with boron at different weight rate.From the XRD analyses,each alloy of this series is mainly composed of(La,Mg)Ni_(3) phase and the LaNi_(5) phase,and the phase abundance of each phase varies with the boron weight rate,moreover,after composition,the c and cell volumes of(La,Mg)Ni_(3) phase increase,and the LaNi_(5) phase keep the same,which indicate that the boron may enter(La,Mg)Ni_(3) phase.The electrochemical studies show that the maximum discharge capacity of the composites decreases,but the cycling life improved.And the high rate discharge ability and exchange impendence spectroscopy(EIS)of the AB_(3) alloys and its composite were also studied.
基金financially supported by the National Natural Science Foundation of China(No.51771076)the Innovative Research Groups of the National Natural Science Foundation of China(No.NSFC51621001)the Guangdong“Pearl River Talents Plan”(No.2017GC010218)。
文摘Recently,exploring appropriate anode materials for current commercial lithium-ion batteries(LIBs) with suitable operating potential and long cycle life has attracted extensive attention.Herein,a novel anode of Bi nanoparticles fully encapsulated in carbon nanosphere framework with uniform yolk-shell nanostructure was prepared via a facile hydrothermal method.Due to the special structure design,this anode of yolk-shell Bi@C can effectively moderate the volume exchange,avoid the aggregation of active Bi nanoparticle and provide superior kinetic during discharge/charge process.Cycling in the voltage of 0.01-2.0 V,yolk-shell Bi@C anode exhibits outstanding Li+storage performance(a reversible capacity over 200 mAh g-1after 400 cycles at 1.25 A g-1) and excellent rate capability(a capacity of 404,347,304,275,240,199 and 163 mAh g-1 at0.05,0.1,0.25,0.5,1.0,1.8 and 3.2 A g-1,respectively).This work indicates that rational design of nanostructured anode materials is highly applicable for the next-generation LIBs.
基金Item Sponsored by National Natural Science Foundation of China(50901011,51105059,51201055)
文摘A new preparation method of Sm2Co17 nanoflakes was investigated. Hard magnetic Sm2 Co17 nanoflakes with thickness of 20-100 nm were obtained by milling in heptane and oleic acid under a magnetic field of 1.5 T for 0.5-20 h. It was shown that higher anisotropic magnetic properties would be induced by the flake-shape anisotropy when the prepared Sm2 Colt particles are milled with a magnetic field. The magnetic anisotropy of flakes after being aligned under the magnetic field of 1.5 T could be further enhanced, and the value of （BH）m was 128 kJ · m a Both anisotropy and properties are better than those of the nano-particles milled without a magnetic field.
