A method of recovering metal from battery waste is provided. The method includes providing a battery waste leachate comprising metal ions and sulphate ions in an acidic medium, contacting the battery waste leachate with a reagent comprising ammonium ions to precipitate the metal ions as a double sulphate salt having formula (NH.sub.4).sub.2M(SO.sub.4).sub.2.Math.6H.sub.2O, wherein M is one or more of Ni, Mn and Co, heating the precipitate at a temperature of 400 C. or more to form an anhydrous precipitate, dissolving the anhydrous precipitate in a solution comprising sulphate ions and crystallizing MSO.sub.4.Math.6H.sub.2O from the resultant solution.

A method of recovering metal from battery waste is provided. The method includes providing a battery waste leachate comprising metal ions and sulphate ions in an acidic medium, contacting the battery waste leachate with a reagent comprising ammonium ions to precipitate the metal ions as a double sulphate salt having formula (NH.sub.4).sub.2M(SO.sub.4).sub.2.Math.6H.sub.2O, wherein M is one or more of Ni, Mn and Co, heating the precipitate at a temperature of 400 C. or more to form an anhydrous precipitate, dissolving the anhydrous precipitate in a solution comprising sulphate ions and crystallizing MSO.sub.4.Math.6H.sub.2O from the resultant solution.

The positive electrode active material includes single crystal particles and polycrystalline particles, the polycrystalline particles are formed by associating a plurality of the single crystal particles, each of the single crystal particles and the polycrystalline particles includes a lithium nickel composite oxide having a layered structure, and the single crystal particles satisfy all relationships of the following formulas (1) to (3). In the formulas (1) to (3), D10, D50 and D90 each represent a particle diameter having an integrated value of 10%, a particle diameter having an integrated value of 50%, and a particle diameter having an integrated value of 90% in a volume-based particle size distribution of the single crystal particles, and D10, D50 and D90 each have units of micrometers.

[00001]$\begin{array}{cc}D102.5& \left(1\right)\end{array}$$\begin{array}{cc}D505.& \left(2\right)\end{array}$$\begin{array}{cc}\left(D90-D10\right)/D503.& \left(3\right)\end{array}$

The positive electrode active material includes single crystal particles and polycrystalline particles, the polycrystalline particles are formed by associating a plurality of the single crystal particles, each of the single crystal particles and the polycrystalline particles includes a lithium nickel composite oxide having a layered structure, and the single crystal particles satisfy all relationships of the following formulas (1) to (3). In the formulas (1) to (3), D10, D50 and D90 each represent a particle diameter having an integrated value of 10%, a particle diameter having an integrated value of 50%, and a particle diameter having an integrated value of 90% in a volume-based particle size distribution of the single crystal particles, and D10, D50 and D90 each have units of micrometers.

[00001]$\begin{array}{cc}D102.5& \left(1\right)\end{array}$$\begin{array}{cc}D505.& \left(2\right)\end{array}$$\begin{array}{cc}\left(D90-D10\right)/D503.& \left(3\right)\end{array}$

This disclosure provides systems, methods, and apparatus related to lithium-ion batteries. In one aspect, a method includes synthesizing an intermediate selected from a group of a nickel-manganese-cobalt nitrate, a nickel-manganese-cobalt acetate, a nickel-manganese-cobalt sulfate, a nickel-manganese-cobalt chloride, and a nickel-manganese-cobalt phosphate. The intermediate is mixed with a lithium salt selected from a group of LiOH, LiCl, LiNO.sub.3, LiSO.sub.4, LiF, LiBr, Li.sub.3PO.sub.4, Li.sub.2CO.sub.3, and combinations thereof to form a mixture. The mixture is annealed at a sequence of temperatures and times to form a plurality of single crystals of a lithium nickel-manganese-cobalt oxide, with no cooling of the mixture between operations of the sequence of temperatures and times.

A positive electrode material and a preparation method thereof, and a lithium-ion battery. The positive electrode material includes a core, an oxygen-absorbing layer, and a passivation layer in sequence from inside to outside; the core includes an oxide composed of Ni, Li, a metal element M, and a non-metal element Q; the metal element M includes at least one of Mg, Al, Zr, Ca, Ti, Sr, Y, Nb, Mo, W, Ta, or Ce; the non-metal element Q includes at least one of F, B, P, or Si; the oxygen-absorbing layer is an unsaturated oxide including a coating element L; the coating element L includes at least one of V, Ga, In, Sn, Bi, Ce, Pr, or Sb; the passivation layer is a compound including element F.

A positive electrode material and a preparation method thereof, and a lithium-ion battery. The positive electrode material includes a core, an oxygen-absorbing layer, and a passivation layer in sequence from inside to outside; the core includes an oxide composed of Ni, Li, a metal element M, and a non-metal element Q; the metal element M includes at least one of Mg, Al, Zr, Ca, Ti, Sr, Y, Nb, Mo, W, Ta, or Ce; the non-metal element Q includes at least one of F, B, P, or Si; the oxygen-absorbing layer is an unsaturated oxide including a coating element L; the coating element L includes at least one of V, Ga, In, Sn, Bi, Ce, Pr, or Sb; the passivation layer is a compound including element F.

Coated cathode active materials include a cathode active material that is coated by a hydroxide-containing material, such as a metal hydroxide. The coated cathode active materials may be incorporated into electrochemical cells, including solid-state batteries. Electrochemical cells including the coated cathode active materials have improved capacity retention as compared to electrochemical cells including un-coated cathode active materials.

Coated cathode active materials include a cathode active material that is coated by a hydroxide-containing material, such as a metal hydroxide. The coated cathode active materials may be incorporated into electrochemical cells, including solid-state batteries. Electrochemical cells including the coated cathode active materials have improved capacity retention as compared to electrochemical cells including un-coated cathode active materials.

The present disclosure provides a positive electrode material, and a preparation method thereof, a positive electrode sheet, and a battery. The positive electrode material includes a nickel-cobalt-manganese-aluminum quaternary positive electrode material and a lithium iron phosphate positive electrode material. A chemical formula of the nickel-cobalt-manganese-aluminum quaternary positive electrode material is Li.sub.(1+u)Ni.sub.vMn.sub.wCo.sub.xAl.sub.yA.sub.zO.sub.2, where u0, v+w+x+y+z=1. A chemical formula of the lithium iron phosphate positive electrode material is Li.sub.1+kFe(PO.sub.4).sub.1+mB.sub.n, in which k, m, and n0; and both A and B are doping elements. A mass ratio of the nickel-cobalt-manganese-aluminum quaternary positive electrode material to the lithium iron phosphate positive electrode material is (0.5 to 7.0):(3.0 to 9.5).