Hydrogen diffusion in La1.5Nd0.5MgNi9 alloy electrodes of the Ni/MH battery

•Hydrogen diffusion in the La1.5Nd0.5MgNi9 alloy electrode was studied.•Various techniques of low amplitude potentiostatic data treatment were used.•DH demonstrates a maximum (2 × 10−11 cm2/s) at 85% of discharge of the electrode.•Maximum is associated with a conversion of β-hydride into a solid α-solution.•Optimization of material and electrode will allow high discharge rates.

Hydrogen diffusion in the La1.5Nd0.5MgNi9 battery electrode material has been studied using low amplitude potentiostatic experiments. Complex diffusion behavior is examined in frames of electroanalytical models proposed for the lithium intercalation materials. Hydrogen diffusion coefficient DH changes with hydrogen content in the metal hydride anode electrode and has a maximum of ca. 2 × 10−11 cm2/s at ca. 85% of discharge. Such a behavior differs from the trends known for the transport in lithium battery materials, but qualitatively agrees with the data for the highly concentrated β-PdHx.

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