Nickel appears quite frequently as a cathode material, particularly in alkaline water electrolysis and large-scale electrochemical systems. It is appreciated for its resistance to alkaline environments and its high catalytic activity in hydrogen evolution reactions. In the current state of battery technology, nickel is an essential component of cathode active materials (NCM or NCA, for example), as it directly influences the energy density and capacity of the cell. And if you look at older vacuum tube technology, the cathode was often made of a nickel tube coated with oxide electron emitters.