Effect of LiBr addition on the electrochemical performance of La₂Mg₁₇/Ni composites prepared by ball milling

Highlights: • The addition of LiBr prevents the crystallization of La₂Mg₁₇/Ni composites. • Amorphous and nanocrystalline granules were obtained by ball milling. • The proportion of nanocrystalline granules increases with LiBr addition. • 5 wt.% LiBr is optimal for maximum discharge capacity and corrosion resistance . • The improved capacity with LiBr addition is due to a decrease in contact resistance. - Abstract: This study examines the microstructure of La₂Mg₁₇/Ni composites produced by ball-milling with lithium bromide, and the effect of varying this LiBr addition on the electrochemical properties of the resulting electrode material. Through this, it was found that LiBr helps prevent crystallization of the alloy, thereby refining the particle size and ensuring a uniform distribution of amorphous and nanocrystalline particles. This structure greatly improved the electrochemical properties of the composite, with the maximum discharge capacity increasing from 176.8 to 550.38 mA h/g. Further investigation of the electrochemical behaviour of the composite electrode revealed that the addition of 5 wt.% LiBr reduces the contact resistance, increases the electrochemical impedance, enhances the limiting current density and improves the charge/discharge equilibrium rate