The choice of material is critical for electrical efficiency and thermal management. You should prioritize Pure Nickel (99.9%) for high-drain applications due to its low internal resistance and excellent corrosion resistance. For cost-sensitive projects with lower current requirements, Nickel-Plated Steel is an option, but ensure the plating thickness is at least 3-5 microns to prevent oxidation. For high-power EV or ESS packs, Copper-Nickel composites or Busbars are preferred to handle higher ampacity while maintaining weldability.