共查询到16条相似文献,搜索用时 156 毫秒
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为制备具有高容量的储氢合金,研究了化学计量比、镁含量、稀土组成和制备技术对混合稀土-镁-镍基储氢合金结构和电化学性能的影响,并给出了典型的测试结果。通过调整合金的化学组成和改进制备工艺,制备了低镁含量的Ml_(0.88)Mg_(0.12)Ni_(3.0)Mn_(0.10)Co_(0.55)Al_(0.10)合金。该合金由CaCu_5型相,Ce_2Ni_7型相和Pr_5Co_(19)型相组成,最大放电容量可以达到386 mAh/g,300个充放电循环后合金的放电容量为315mAh/g,仍为最大放电容量的81.6%。 相似文献
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Cu的添加对Mg2Ni合金储氢性能的影响 总被引:1,自引:0,他引:1
采用机械合金化法,制备了Mg2Ni1-xCux(x=0、0.1、0. 3)合金,研究了Cu对Mg2Ni储氢合金储氢性能的影响.XRD和SEM研究表明Cu的加入使合金中产生了Cu11Mg10Ni9新相.利用PCT测试仪测定了合金的储氢性能,结果表明,添加Cu元素会降低合金的吸氢量,但能有效地提高放电容量和循环稳定性.制备出的Mg2Ni0.9Cu0.1与Mg2Ni0.7Cu0.3相比,前者具有较大的吸氢量,后者的放电容量较大,循环稳定性较好. 相似文献
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氢能的有效开发和应用主要需解决氢的安全、高效储运瓶颈问题。MgH_2具有高储氢容量、资源丰富以及成本低廉等优点,被认为是最具发展前途的一类储氢材料。但是,MgH_2较高吸放氢温度和较慢吸放氢速率限制了其实际应用。核壳结构纳米镁基储氢材料有助于材料储氢性能的改善,目前已取得了大量成果。本文针对国内外纳米镁基核壳结构储氢体系研究现状,归纳了该类储氢材料的制备方法,重点阐述和总结了其吸放氢热力学动力学性能、微观结构、物相变化,并对该领域的研究成果和方向进行了总结和展望,指出调控核壳结构镁基材料的纳米尺寸、添加高效纳米催化剂及其综合协同作用是镁基储氢材料领域未来的研究趋势和重要研究方向。 相似文献
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Al的添加对Mg2Ni储氢合金结构和氢扩散能力的影响研究 总被引:4,自引:1,他引:3
采用烧结-机械球磨二步法制备了Mg2-xAlxNi(x=0、0.3)储氢合金材料,研究了Al元素的加入对Mg2Ni储氢合金结构和氢扩散能力的影响.XRD和SEM研究表明Al 元素的加入会使储氢合金产生Al3Ni2和Mg3AlNi2新相,并且在表面覆盖分布各异的棱角多边形颗粒,利用循环伏安法测定了Mg2-xAlxNi(x=0、0.3)储氢电极的氢扩散系数,结果表明:Al元素的加入能显著改善Mg2Ni储氢合金结构,提高了氢扩散能力. 相似文献
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Lichao Pei Shumin Han Jiasheng Wang Lin Hu Xin Zhao Baozhong Liu 《Materials Science and Engineering: B》2012,177(18):1589-1595
RMg2Ni alloys were prepared by inductive melting where R is rare earth (R = La, Ce, Pr, Nd). X-ray diffraction (XRD) patterns revealed a single-phase composition of RMg2Ni phase when R was one of the three elements (La, Pr, Nd), and a double-phase composition of CeMg2Ni and CeMg3 phases when R was Ce. In the hydriding process, RMg2Ni phases transformed to rare earth hydrides (R-H) and Mg2NiH4 phase, and for CeMg3 phase, it is decomposed to CeH2.74 and MgH2 phases. The enthalpy change of Mg2Ni phase in RMg2Ni alloys during the hydriding/dehydriding process was smaller compared with that of pristine Mg2Ni alloy, which could be attributed to the existence of R-H. The hydrogen storage properties of RMg2Ni alloys changed with different R compositions in R-H. At 573 K, the NdMg2Ni alloy had the highest hydrogen storage capacity and dehydriding plateau, and the descending order of hysteresis was PrMg2Ni < NdMg2Ni < CeMg2Ni < LaMg2Ni, which suggested that the PrMg2Ni alloy exhibited a better cycling stability and reversibility than the other three alloys. At 523 K, the uptake time of RMg2Ni alloys to reach 90% of the maximum hydrogen storage capacity was 75 s, 34 s, 65 s and 52 s, respectively, compared with 110 s of pristine Mg2Ni alloy. Therefore, we believed the R-H in the alloys not only improved their thermodynamic properties but also accelerated their hydriding kinetics. 相似文献
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为改善Ti(Cr-Mn)2 AB2型合金的储氢性能,采用A侧过化学计量和过渡金属部分替代Mn进行多元合金化,系统研究了Tix(Cr-Mn-M)2(x=1.0,1.1;M=V、Fe、Ni、Cu)合金的储氢性能.研究结果表明,V、Fe、Ni、Cu部分替代Mn进行多元合金化后,合金主相仍保持C14(MgZn2)型Laves相,合金晶胞体积增大.合金化元素部分替代Mn后合金的活化性能得到明显改善,合金吸放氢量增大,吸放氢压力滞后减小.除Fe使合金放氢平台压力有所升高外,其余合金化元素均使合金的吸放氢平衡压力有不同程度的降低,这是由于合金的晶胞体积增大所致.在所形成的合金中,以Ti1.1Cr1.2Mn0.5CuO0.3的综合性能最好,其室温下吸放氢量分别达到1.95%和1.72 9,6(质量分数).采用该合金与自制的轻质高压储氢容器(工作压力为40MPa)复合组成金属氢化物复合式高压储氢器,对其储氢密度的计算结果表明,当储氢合金的填充量(体积分数)达到0.20时,该复合式储氢器总的体积储氢密度将提高57%. 相似文献
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《Materials Research Bulletin》1987,22(12):1653-1658
The absorption-desorption properties of LaMg11Ni and La0.9Ca0.1Mg11Ni alloys with respect to hydrogen are investigated. The results obtained on the hydrogen desorption rate from the hydrided alloys are compared with data on this rate found with the isostructural alloys LaMg12 and La0.9Ca0.1Mg12 as well as with the binary alloy La2Mg17 and its analogues La2Mg16Ni, La1.8Ca0.2Mg17 and La1.8Ca0.2Mg16Ni. It is shown that the partial substitution of nickel for magnesium in lanthanum-magnesium alloys causes acceleration of the desorption of hydrogen stored in them. The extent of this effect depends on the number and character of phases formed during hydriding of the alloys. 相似文献