Dinickel boride is a chemical compound of nickel and boron with formula . It is one of the borides of nickel.
The formula "" and the name "nickel boride" are often used for a nickel-boron catalyst obtained by reacting nickel salts with sodium borohydride. However, that product is not a well-defined compound, and its bulk formula is closer to .
Dinickel boride can be obtained (together with other nickel borides) by heating sodium borohydride with powdered nickel metal up to 670 ðC in a closed vessel, so that the released hydrogen creates a pressure of up to 3.4 MPa. The main reactions can be summarized as
but other reactions occur, yielding other borides.