Example 8
The diverging Cu—Ni dendrites were electrodeposited on the obtained porous Cu—Ni foams at a potential of −1.2 V (vs. Ag/AgCl) for 150 coulombs from an electrolyte made of nickel sulfamate [Ni(SO3NH2)2, 0.5M], nickel chloride (NiCl2, 0.1M), copper chloride (CuCl2, 0.0025M), and boric acid (H3BO3, 0.323M) with nickel foil (Alfa Aesar, MA, USA) working as the counter electrode. The electrodeposition was sequentially repeated four times with the porous Cu—Ni foam substrate rotated upside-down each time to ensure an even coverage of the dendrites. The electrolyte was also replaced every two depositions to replenish the copper ions available for the formation of diverging branches. Upon completion of all four electrodepositions, the Cu—Ni foams were rinsed with deionized water and annealed at 1000° C. in a gas mixture (H2, 5 sccm and N2, 50 sccm) for 5 min to enhance the adhesion between the Cu—Ni dendrites and Cu—Ni foam struts.
