添加Mn和Co对V_(80)Ti_8Cr_(12)合金储氢性能的影响

Effects of Mn and Co Addition on Hydrogen Storage Properties of V_(80)Ti_8Cr_(12) Alloy

研究了添加Mn和Co对V_(80)Ti_(8-x-y)Cr_(12)Mn_xCo_y(x=0,1,2,3;y=0,0.1,0.2,0.4,0.8,1.0)合金组织结构和储氢性能的影响。结果表明:所有的合金均为bcc单相结构。Mn的添加减小了合金bcc相的晶格常数,平台压升高,平台斜率因子减小,残余氢量减少,然而合金的吸放氢量均有所降低。在V_(80)Ti_7Cr_(12)Mn_1基础上添加Co,随着Co含量的增加,合金的平台压升高,斜率因子减小,吸氢量和有效放氢量均先增加后降低,但有效放氢量均能保持在2.2%以上。当Co含量为0.2at%时,得到合金V_(80)Ti_(6.8)Cr_(12)Mn_1Co_(0.2)在273K吸氢量达到最大为3.81%(质量分数),313K有效放氢量为2.45%,平台压为0.68Mpa。对V_(80)Ti_(6.8)Cr_(12)Mn_1Co_(0.2)合金进行短期循环性能测试得到合金具有良好的循环稳定性,随着循环次数的增加合金的吸氢量变化缓慢,15次循环后的有效放氢量为2.38%。

Effects of of Mn and Co addition on hydrogen-storage microstructure and properties of V_(80)Ti_(8-x-y)Cr_(12)Mn_xCo_y ( x = 0,1,2,3; y = 0,0. 1,0. 2,0. 4,0. 8,1. 0) alloy have been investigated. The results show that these alloys are determined as a single bcc phase. With the increase of Mn addition,the lattice parameters of bcc main phase and the plateau slope factor of alloys are reduced,the plateau pressure isincreased,and the residual amount of hydrogen of alloys is decreased. However,the hydrogen absorption capacity and desorption capacity are decreased. Based on this alloy,With the increase of Co addition,the plateau pressure of alloys is improved,the plateau slope factor is reduced and the maximum capacity and effective capacity of hydrogen storage are raised and then? decreased. While the effective desorption capacities maintain more than 2. 2%. When y = 0. 2at%,the alloy shows the maximum hydrogen absorption capacity of 3. 81% at 273 K and the effective desorption capacities of 2. 45%,with a plateau pressure of 0. 68 MPa at 318 K. The V_(80)Ti_(6.8)Cr_(12)Mn_1Co_(0.2) alloy shows good short-term cycle durability with the effective desorption capacities of 2. 38% after the fifth cycle.