This application pertains to methods of recovering metals from metal sulfides that involve contacting the metal sulfide with an acidic sulfate solution containing ferric sulfate and a reagent that has a thiocarbonyl functional group, wherein the concentration of reagent in the acidic sulfate solution is sufficient to increase the rate of metal extraction relative to an acidic sulfate solution that does not contain the reagent, to produce a pregnant solution containing the metal ions.

An electrode active material in the present disclosure has at least one O2-like structure selected from among of an O2-type structure, a T#2-type structure, and an O6-type structure. The crystallite size of the O2-like structure that is measured by XRD is 400 or more and 1000 or less.

An electrode active material in the present disclosure has at least one O2-like structure selected from among of an O2-type structure, a T#2-type structure, and an O6-type structure. The crystallite size of the O2-like structure that is measured by XRD is 400 or more and 1000 or less.

An electrode active material in the present disclosure has at least one O2-like structure selected from among an O2-type structure, a T#2-type structure, and an O6-type structure, and has a chemical composition shown as Li.sub.aNa.sub.bNi.sub.x-pCO.sub.y-qMn.sub.z-rM.sub.p+q+rO.sub.2(0<a1.00, 0b0.20, 0.15<x<0.35, 0.15<y<0.45, 0.25<z<0.50, x+y+z=1, and 0p+q+r<0.17 are satisfied, and an element M is at least one element selected from among B, Mg, Al, K, Ca, Ti, V, Cr, Fe, Cu, Zn, Ga, Ge, Sr, Y, Zr, Nb, Mo, and W).

An electrode active material in the present disclosure has at least one O2-like structure selected from among an O2-type structure, a T#2-type structure, and an O6-type structure, and has a chemical composition shown as Li.sub.aNa.sub.bNi.sub.x-pCO.sub.y-qMn.sub.z-rM.sub.p+q+rO.sub.2(0<a1.00, 0b0.20, 0.15<x<0.35, 0.15<y<0.45, 0.25<z<0.50, x+y+z=1, and 0p+q+r<0.17 are satisfied, and an element M is at least one element selected from among B, Mg, Al, K, Ca, Ti, V, Cr, Fe, Cu, Zn, Ga, Ge, Sr, Y, Zr, Nb, Mo, and W).

The present invention provides a process for preparing a high-purity nickel sulphate solution, comprising the steps of: i. forming an aqueous mixed metal sulphate solution by reacting sulphuric acid with a raw material feed comprising nickel, manganese, cobalt, and magnesium in an aqueous medium; ii. extracting manganese from said aqueous mixed metal sulphate solution, thereby obtaining a first aqueous raffinate comprising nickel, cobalt and magnesium, and a manganese-rich organic phase; iii. extracting cobalt from said first aqueous raffinate, thereby obtaining a second aqueous raffinate comprising nickel and magnesium, and a cobalt-rich organic phase; and iv. extracting magnesium from said second aqueous raffinate solution, thereby obtaining a high-purity nickel sulphate solution, and a magnesium-rich organic phase.

The present invention provides a process for preparing a high-purity nickel sulphate solution, comprising the steps of: i. forming an aqueous mixed metal sulphate solution by reacting sulphuric acid with a raw material feed comprising nickel, manganese, cobalt, and magnesium in an aqueous medium; ii. extracting manganese from said aqueous mixed metal sulphate solution, thereby obtaining a first aqueous raffinate comprising nickel, cobalt and magnesium, and a manganese-rich organic phase; iii. extracting cobalt from said first aqueous raffinate, thereby obtaining a second aqueous raffinate comprising nickel and magnesium, and a cobalt-rich organic phase; and iv. extracting magnesium from said second aqueous raffinate solution, thereby obtaining a high-purity nickel sulphate solution, and a magnesium-rich organic phase.

A method for producing a mixed metal solution containing manganese ions and at least one of cobalt ions and nickel ions, the method including: an Al removal step of subjecting an acidic solution containing at least manganese ions and aluminum ions, and at least one of cobalt ions and nickel ions, to removal of the aluminum ions by extracting the aluminum ions into a solvent while leaving at least a part of the manganese ions in the acidic solution in an aqueous phase, the acidic solution being obtained by subjecting battery powder of lithium ion batteries to a leaching step; and a metal extraction step of bringing an extracted residual liquid obtained in the Al removal step to an equilibrium pH of 6.5 to 7.5 using a solvent containing a carboxylic acid-based extracting agent, extracting at least one of the manganese ions and at least one of the cobalt ions and the nickel ions into the solvent, and then back-extracting the manganese ions and at least one of the cobalt ions and nickel ions.

A method for producing a mixed metal solution containing manganese ions and at least one of cobalt ions and nickel ions, the method including: an Al removal step of subjecting an acidic solution containing at least manganese ions and aluminum ions, and at least one of cobalt ions and nickel ions, to removal of the aluminum ions by extracting the aluminum ions into a solvent while leaving at least a part of the manganese ions in the acidic solution in an aqueous phase, the acidic solution being obtained by subjecting battery powder of lithium ion batteries to a leaching step; and a metal extraction step of bringing an extracted residual liquid obtained in the Al removal step to an equilibrium pH of 6.5 to 7.5 using a solvent containing a carboxylic acid-based extracting agent, extracting at least one of the manganese ions and at least one of the cobalt ions and the nickel ions into the solvent, and then back-extracting the manganese ions and at least one of the cobalt ions and nickel ions.

A method for producing nickel sulfate according to exemplary embodiments may prepare a raw material containing nickel. A first leachate may be produced by selectively leaching nickel from the raw material containing nickel using an oxidant. A second leachate may be produced by separating a residual metal from the first leachate. Thereafter, nickel sulfate may be obtained from the second leachate. Accordingly, unnecessary byproducts may be reduced by omitting a separate nickel extraction step.