A flotation method for separating cathode material from anode and other carbon materials is described. The cathode material may be that including lithium, nickel, and cobalt or that including lithium iron phosphate. The starting material for the flotation process is conventional black mass as recovered from fractured lithium-ion batteries and lithium-ion battery production scrap. The fractured lithium-ion batteries may originate from spent batteries including used batteries and/or out of specification new production batteries. A very fine mesh screening preferably is used to remove interfering binder from the black mass powder prior to froth flotation, preferably in combination with a hydrophilic depressant to enhance separation of the cathode material from the anode and other carbon materials present in the black mass. The separated cathode and anode materials recovered from the method may be used directly or augmented with additional lithium to form new LIB cathodes, anodes, and batteries.