In this study, the evolution trends in various hydrogen storage properties as well as kinetics performance of LaNi_5−xCo_x (x = 0, 0.25, 0.50 and 0.75) alloys up to 1000 cycles are studied, and the effects of Co on the long-term hydrogen absorption/desorption properties are revealed. The alloys have single LaNi₅ phase structure. The cell volume increases with increasing Co content, resulting in a lower hydrogen absorption/desorption plateau pressure and a more stable hydride phase. The alloys have good kinetics performance and can fully absorb hydrogen within 300 s. The hydrogen absorption rate increases with either cycling or Co addition, but neither of them changes the rate limiting step which remains to be diffusion controlled model in the temperature range of 343–383 K. With cycling, an intermediate γ phase emerges with the coexistence of α and β phases indicated by an extra higher plateau in P-C-T curves. This γ phase acts as a buffer releasing the microstrains which is reflected from the slower capacity degradation, and the significant decrease in hysteresis and slope factor upon its appearance. Moreover, the c/a value increases after 1000 cycles which also relieves the microstrains in the alloys. Co addition not only enhances the buffer effect of γ phase by partially combining it with β phase, but also promotes the increasing degree of c/a value, contributing to a better crystal structure, bigger particle size and higher cycle stability during long-term cycling.

在这项研究中，研究了 多达1000个循环的LaNi _{5− x} Co _x（x = 0、0.25、0.50和0.75）合金在各种储氢特性中的演化趋势以及动力学性能，并且研究了Co对合金的影响。揭示了长期的氢吸收/解吸性能。合金具有单一的LaNi ₅相结构。电池体积随Co含量的增加而增加，从而导致较低的氢吸收/解吸平稳压力和更稳定的氢化物相。该合金具有良好的动力学性能，可以在300 s内完全吸收氢。氢的吸收率随循环或添加Co的增加而增加，但是它们都没有改变限速步骤，该限速步骤仍然是343-383 K温度范围内的扩散控制模型。PCT曲线中的更高平稳期表明了α和β相。γ相充当缓冲剂，释放出微应变，这从较慢的容量退化以及其出现时的磁滞和斜率因子显着降低反映出来。而且，1000次循环后c / a值增加，这也减轻了合金中的微应变。钴的添加不仅可以通过与β相部分结合来增强γ相的缓冲作用，而且还可以提高c / a值，从而在长期循环中具有更好的晶体结构，更大的粒径和更高的循环稳定性。 。