镧镍储氢合金改性制备及吸/放氢性能研究

Modification and preparation of lanthanum nickel hydrogen storage alloy and study of hydrogen absorption/desorption performance

镧镍合金(LaNi_(5))是公认的性能优良的常温储氢材料,成为固态储氢材料的热门研究对象,然而在循环吸/放氢过程中,材料晶格会因膨胀和收缩导致合金严重粉化,进而缩短其循环使用寿命.为研究掺杂不同质量分数膨胀石墨(EG)的LaNi_(5)-x%EG粉末/压片混合材料的吸/放氢循环稳定性,通过实验获得掺杂EG改性后的镧镍合金导热系数、吸/放氢温度和吸/放氢量.实验结果表明:与LaNi_(5)合金粉末相比,LaNi 5-5.0%EG粉末在100 MPa压力下固化压片后导热系数是其16.47倍,吸氢量提高了47.9%,放氢量提高了144.8%,具有更适合的吸/放氢能力,可进一步应用于大规模的固态储氢场合.

Lanthanum nickel alloy(LaNi_(5))is recognized as an excellent hydrogen storage material at room temperature,and has become a hot research object of solid hydrogen storage materials.However,in the process of cyclic hydrogen absorption/desorption,the material lattice will cause serious pulverization of the alloy due to expansion and contraction,which shortens the cyclic service life.In order to explore the hydrogen absorption/desorption cyclic stability of LaNi_(5)-x%expanded graphite(EG)powder/tablet mixed materials doped with different mass fractions of EG,the thermal conductivity,hydrogen absorption/desorption temperature and hydrogen absorption/desorption capacity of the modified lanthanum nickel alloy doped with EG are obtained through experiments.The experimental results show that the thermal conductivity of LaNi 5-5.0%EG tablet sample cured under 100 MPa pressure is 16.47 times of that of LaNi 5 alloy powder;the hydrogen absorption capacity is increased by 47.9%,and the hydrogen desorption capacity is increased by 144.8%compared with LaNi_(5) alloy powder,so it has more suitable hydrogen storage capacity,and can be applied to large-scale solid hydrogen storage.