A study on the improvement of the cyclic durability by Cr substitution in V–Ti alloy and surface modification by the ball-milling process

Effects of Cr on the structural and electrochemical properties of TiV-based two-phase hydrogen storage alloys

“…Yu et al [9] reported that Cr substitution for Mn in the Ti-based AB 2 type alloy electrode effectively improved the cycle life of the electrode by reducing the dissolution of V in alkali solution and restraining the formation of TiO 2 film, which was believed to be the dominating factor in the degradation of the alloy [10]. Kim et al [11] reported that Cr substitution for V in the V-Ti alloy improved the cycle life markedly, but the discharge capacity decreased rapidly with increasing Cr content.…”

Improved electrochemical performance of BCC alloy by Ni addition and surface modification with AB5 alloy

“…After 100 cycles, the discharge capacity decreased to 189 mAh g −1 , which is only 63% of the maximum discharge capacity. The ICP-AES measurement revealed a high content of V ion in the electrolyte after 100 cycles, suggesting that the rapid degradation of discharge capacity is probably due to the undesirable dissolution of V into the electrolyte during the charge-discharge cycles [8], in addition, the formation of a TiO 2 layer on the surface of the alloy during the charge-discharge cycles might be another reason for reducing the discharge capacity [9].…”

“…It was found that addition of Ni in Ti-V-based alloy system to form a second phase such as TiNi phase or Laves-type phase, which works as a micro-current collector and electro-catalyst, is effective in improving the discharge ability of the Ti-V-based alloys [7]. However, the discharge capacity of the resultant alloy rapidly decreased during charge-discharge cycling [8,9]. Further studies revealed that addition of Nb and Co to the alloy effectively improved the cycle stability without considerable decreasing in initial capacity and without much degradation of initial activation characteristics [10].…”

Effect of AB5 alloy on Ti0.10Zr0.15V0.35Cr0.10Ni0.30 hydrogen storage alloy

“…In recent years, many researchers have been interested in Ti-Cr-Vbased solid solution alloys because maximum hydrogen storage capacity of the alloy reaches about 3.7 wt.%, but the rechargeable hydrogen storage capacity is limited to only about half of that. It is reported that the hydriding property of the alloy has been improved by surface modification [8], annealing treatment [9] and additive elements [10][11][12][13].…”