Effects of annealing and NaOH pretreatment on an LmNi3.65Al0.34Mn0.27Co0.74 hydrogen storage alloy

Effects of pretreatment on MlNi4.00Co0.45Mn0.38Al0.3 hydrogen storage alloy powders and the performance of 6 Ah prismatic traction battery

“…The formation of micro-voids is due to the deposition of the metal oxides and hydroxides on the alloy surface, which leads to the formation of the porous surface by corrosion and etching of the alloy surfaces. Meanwhile, this porous surface with enriched Ni and Co atoms can also raise the oxidation resistance of alloy [43,46,47].…”

“…So the enhancement of highrate and low-temperature discharge capability could be attributed to the improvement of electrocatalytic activity and surface electric conductivity of alloy powders because of the enriched Ni and Co metal layers, the inhibition of oxidization and pulverization, and the increase of the diffusion coefficient of the hydrogen in a phase due to the removal of oxide film by alkaline pretreatment [43,46,52,53].…”

“…Corrosion is dependent on the composition of alloys and can be controlled by the surface treatment of the alloy powder. The structure changes caused by alkali-treatment on alloy surface can i n t e r n a t i o n a l j o u r n a l o f h y d r o g e n e n e r g y 3 7 ( 2 0 1 2 ) 1 2 3 8 4 e1 2 3 9 2 enhance the corrosion resistance and suppress the change in negative electrode [43,46,47]. Thus, the improved cycling performance should be attributed to the enriched Ni and Co layers, which can prevent the hydrogen storage alloy from being oxidized and inhibit the corrosion and pulverization of alloy powders.…”