A LiFePO4/(C+Fe2P) composite cathode material was prepared by a sol-gel method using Fe(NO3)3.9H20, LiAc·H2O), NHaH2PO4 and citric acid as raw materials, and the physical properties and electrochemical perf...A LiFePO4/(C+Fe2P) composite cathode material was prepared by a sol-gel method using Fe(NO3)3.9H20, LiAc·H2O), NHaH2PO4 and citric acid as raw materials, and the physical properties and electrochemical performance of the composite cathode material were investigated by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electrochemical tests. The Fe2P content, morphology and electrochemical performance of LiFePOa/(C+Fe2P) composite depend on the calcination temperature. The optimized LiFePO4/(C+FeeP) composite is prepared at 650 ~C and the optimized composite exhibits sphere-like morphology with porous structure and Fe2P content of about 3.2% (mass fraction). The discharge capacity of the optimized LiFePO4/(C+FeRP) at 0.1C is 156 and 161 mA.h/g at 25 and 55 ℃, respectively, and the corresponding capacity retentions are 96% after 30 cycles; while the capacity at 1C is 142 and 149 mA.h/g at 25 and 55 ℃, respectively, and the capacity still remains 135 and 142 mA-h/g after 30 cycles at 25 and 55℃, respectively.展开更多
Hardness, friction and wear characteristics of electrodeposited RE Ni W P B 4C PTFE composite coatings were studied, and the reason for these fine characteristics was explained in respect of structure. The results sho...Hardness, friction and wear characteristics of electrodeposited RE Ni W P B 4C PTFE composite coatings were studied, and the reason for these fine characteristics was explained in respect of structure. The results show that 1) the structure of RE Ni W P B 4C PTFE composite coatings experiences a transformation process from amorphous to mixture then to crystal as the heat treatment temperature rises; 2) incorporating of B 4C greatly increases the hardness of the coating; 3) the wear resistance of the coating is best with heat treatment for 1?h at 300?℃, which is greatly superior to that of the other traditional coatings.展开更多
Catalytic hydrogenation is an appropriate method for the improvement of C9 petroleum resin(C9PR) quality. In this study, the Ni2P/SiO2(containing 10% of Ni) catalyst prepared by the temperature-programmed reductio...Catalytic hydrogenation is an appropriate method for the improvement of C9 petroleum resin(C9PR) quality. In this study, the Ni2P/SiO2(containing 10% of Ni) catalyst prepared by the temperature-programmed reduction(TPR) method was used for hydrogenation of C9 petroleum resins. The effect of reaction conditions on catalytic performance was studied, and the results showed that the optimum reaction temperature, pressure and liquid hourly space velocity(LHSV) was 250 ℃, 6.0 MPa, and 1.0 h-1, respectively. The bromine numbers of hydrogenated products were maintained at low values(250 mg Br/100g) within 300h, showing the high activity and stability of Ni2P/SiO2 catalyst. The fresh and spent catalysts were characterized by X-ray diffraction(XRD), BET surface area(BET) analysis, scanning electron microscopy(SEM), transmission electron microscopy(TEM), Fourier transform infrared(FTIR) pyridine adsorption, and X-ray photoelectron spectroscopy(XPS). Compared with the traditional sulfurated-Ni W catalysts, Ni2P possessed globe-like structure instead of layered structure like the active phase of Ni WS, thereof exposing more active sites, which were responsible for the high activity of Ni2P/SiO2 catalyst. The stability of Ni2P/SiO2 catalyst was probably attributed to its high sulfur tolerance, antisintering, anti-coking and carbon-resistance ability. These properties might be further ascribed to the special Ni-P-S surface phase, high thermal stability of Ni2P nanoparticles and weak surface acidity for the Ni2P/SiO2 catalyst.展开更多
研究了硬质合金表面Ni P 纳米Ti(C,N)化学复合镀工艺以及热处理对复合镀层性能影响的规律。结果表-);2)较好的明:1)施镀工艺中各因素对镀速影响的显著性顺序是:温度→pH值→纳米Ti(C,N)加入量→χ(Ni2+ H2PO2施镀工艺为:28g L氯化镍、... 研究了硬质合金表面Ni P 纳米Ti(C,N)化学复合镀工艺以及热处理对复合镀层性能影响的规律。结果表-);2)较好的明:1)施镀工艺中各因素对镀速影响的显著性顺序是:温度→pH值→纳米Ti(C,N)加入量→χ(Ni2+ H2PO2施镀工艺为:28g L氯化镍、25.76g L次亚磷酸钠,50g L氯化铵、45g L柠檬酸钠,0.001g LPbCl2,6g L纳米Ti(C,N),pH=10,温度为80℃。3)Ni P 纳米Ti(C,N)复合镀层较优的热处理工艺为:在400℃保温150min。采用所推荐的施镀和热处理工艺,获得了硬度是硬质合金基体硬度的2.16倍的Ni P 纳米Ti(C,N)复合镀层。并对以上结果产生的原因进行了简单讨论。展开更多
基金Project(50571091) supported by the National Natural Science Foundation of ChinaProject(09C947) supported by the Scientific Research Fund of Hunan Provincial Education Department,China
文摘A LiFePO4/(C+Fe2P) composite cathode material was prepared by a sol-gel method using Fe(NO3)3.9H20, LiAc·H2O), NHaH2PO4 and citric acid as raw materials, and the physical properties and electrochemical performance of the composite cathode material were investigated by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electrochemical tests. The Fe2P content, morphology and electrochemical performance of LiFePOa/(C+Fe2P) composite depend on the calcination temperature. The optimized LiFePO4/(C+FeeP) composite is prepared at 650 ~C and the optimized composite exhibits sphere-like morphology with porous structure and Fe2P content of about 3.2% (mass fraction). The discharge capacity of the optimized LiFePO4/(C+FeRP) at 0.1C is 156 and 161 mA.h/g at 25 and 55 ℃, respectively, and the corresponding capacity retentions are 96% after 30 cycles; while the capacity at 1C is 142 and 149 mA.h/g at 25 and 55 ℃, respectively, and the capacity still remains 135 and 142 mA-h/g after 30 cycles at 25 and 55℃, respectively.
文摘Hardness, friction and wear characteristics of electrodeposited RE Ni W P B 4C PTFE composite coatings were studied, and the reason for these fine characteristics was explained in respect of structure. The results show that 1) the structure of RE Ni W P B 4C PTFE composite coatings experiences a transformation process from amorphous to mixture then to crystal as the heat treatment temperature rises; 2) incorporating of B 4C greatly increases the hardness of the coating; 3) the wear resistance of the coating is best with heat treatment for 1?h at 300?℃, which is greatly superior to that of the other traditional coatings.
文摘以镍为金属中心、对二甲苯二磷酸为有机配体,构筑了一种有机磷酸类Ni-MOF前驱体,再经过一步碳化,原位制备出多孔碳包覆Ni_2P纳米颗粒的复合材料.该复合材料保留了前驱体的片状形貌,比表面积可达202 m2/g,复合材料中的Ni_2P纳米颗粒具有良好的结晶度,颗粒均匀且无团聚现象.在锂离子电池性能测试中,该Ni_2P/C复合结构在缓解材料体积膨胀的同时提高了材料的电子和离子电导率,进而提高了材料的电化学性能.在0.2 C的电流密度下,材料首次充、放电比容量分别为247和226 m A·h·g-1,库仑效率可达91.7%,循环200圈后,库仑效率接近100%.
基金financially supported by the Scientific Research Fund of Zhejiang Provincial Education Department (Y201225114)the Natural Science Foundation of Zhejiang Province (LY13B030006)
文摘Catalytic hydrogenation is an appropriate method for the improvement of C9 petroleum resin(C9PR) quality. In this study, the Ni2P/SiO2(containing 10% of Ni) catalyst prepared by the temperature-programmed reduction(TPR) method was used for hydrogenation of C9 petroleum resins. The effect of reaction conditions on catalytic performance was studied, and the results showed that the optimum reaction temperature, pressure and liquid hourly space velocity(LHSV) was 250 ℃, 6.0 MPa, and 1.0 h-1, respectively. The bromine numbers of hydrogenated products were maintained at low values(250 mg Br/100g) within 300h, showing the high activity and stability of Ni2P/SiO2 catalyst. The fresh and spent catalysts were characterized by X-ray diffraction(XRD), BET surface area(BET) analysis, scanning electron microscopy(SEM), transmission electron microscopy(TEM), Fourier transform infrared(FTIR) pyridine adsorption, and X-ray photoelectron spectroscopy(XPS). Compared with the traditional sulfurated-Ni W catalysts, Ni2P possessed globe-like structure instead of layered structure like the active phase of Ni WS, thereof exposing more active sites, which were responsible for the high activity of Ni2P/SiO2 catalyst. The stability of Ni2P/SiO2 catalyst was probably attributed to its high sulfur tolerance, antisintering, anti-coking and carbon-resistance ability. These properties might be further ascribed to the special Ni-P-S surface phase, high thermal stability of Ni2P nanoparticles and weak surface acidity for the Ni2P/SiO2 catalyst.
文摘 研究了硬质合金表面Ni P 纳米Ti(C,N)化学复合镀工艺以及热处理对复合镀层性能影响的规律。结果表-);2)较好的明:1)施镀工艺中各因素对镀速影响的显著性顺序是:温度→pH值→纳米Ti(C,N)加入量→χ(Ni2+ H2PO2施镀工艺为:28g L氯化镍、25.76g L次亚磷酸钠,50g L氯化铵、45g L柠檬酸钠,0.001g LPbCl2,6g L纳米Ti(C,N),pH=10,温度为80℃。3)Ni P 纳米Ti(C,N)复合镀层较优的热处理工艺为:在400℃保温150min。采用所推荐的施镀和热处理工艺,获得了硬度是硬质合金基体硬度的2.16倍的Ni P 纳米Ti(C,N)复合镀层。并对以上结果产生的原因进行了简单讨论。