The phrase "nickel base" refers to a type of material or alloy that has nickel as its main component. It means that the material is primarily made up of nickel, which gives it certain properties and characteristics. Full definition
The gas / electric vehicle will use a much more efficient lithium ion battery pack, as opposed to today's nickel based energy storage devices. (topspeed.com)
Uttermost's Ambler Driftwood Polished Nickel Table Lamp designed by David Frisch features a polished nickel base with faux driftwood suspended within its circular design. (bedbathandbeyond.com)
I think the alligator leather upholstery with the brushed nickel base on this chair is quite striking. (anecdotalgoat.com)