The present application relates to the field of lithium-ion batteries and discloses a cathode material, a preparation method thereof, and a lithium-ion battery. The cathode material has a microscopic residual stress measured by XRD and ranging from 0.01 to 0.15. The cathode material has an average diameter D measured by SEM and a grain diameter R measured by XRD, where D/R ranges from 1.4 to 2.5. As cathode material has the microscopic residual stress within a specific range and the ratio of average diameter to grain diameter ratio (D/R) within a specific range, the cathode material can have significantly improved electrochemical performances and thermal stability.

The present application relates to the field of lithium-ion batteries and discloses a cathode material, a preparation method thereof, and a lithium-ion battery. The cathode material has a microscopic residual stress measured by XRD and ranging from 0.01 to 0.15. The cathode material has an average diameter D measured by SEM and a grain diameter R measured by XRD, where D/R ranges from 1.4 to 2.5. As cathode material has the microscopic residual stress within a specific range and the ratio of average diameter to grain diameter ratio (D/R) within a specific range, the cathode material can have significantly improved electrochemical performances and thermal stability.

Provided are an agglomeration-like multi-element cathode material, a preparation method therefor, a use thereof, and a lithium-ion battery. The chemical formula of the agglomeration-like multi-element cathode material is Li.sub.aNi.sub.xCo.sub.yMn.sub.zM.sub.bO.sub.2, wherein 0.9a1.1, 0.5x<1, 0<y<0.5, 0<z<0.5, and 0b<0.05; and M is at least one of V, Ta, Cr, La, Al, Ce, Er, Ho, Y, Mg, Sr, Ba, Ra, Zr, Fe, Ca, Zn, B, W, Nb, Cd, Pb, Si, Mo, Cu, Sr, and Ti. The multi-element cathode material is secondary particles formed by agglomeration of primary particles. The primary particles are spherical or spherical-like and have an average particle size D.sub.S ranging from 0.9 to 2.4 m. The secondary particles have an average particle size D.sub.L ranging from 5 to 15 m. A value of D.sub.L/D.sub.S ranges from 5 to 16. The agglomeration-like multi-element cathode material has high energy density, good rate capability, and excellent cycle stability.

Provided are an agglomeration-like multi-element cathode material, a preparation method therefor, a use thereof, and a lithium-ion battery. The chemical formula of the agglomeration-like multi-element cathode material is Li.sub.aNi.sub.xCo.sub.yMn.sub.zM.sub.bO.sub.2, wherein 0.9a1.1, 0.5x<1, 0<y<0.5, 0<z<0.5, and 0b<0.05; and M is at least one of V, Ta, Cr, La, Al, Ce, Er, Ho, Y, Mg, Sr, Ba, Ra, Zr, Fe, Ca, Zn, B, W, Nb, Cd, Pb, Si, Mo, Cu, Sr, and Ti. The multi-element cathode material is secondary particles formed by agglomeration of primary particles. The primary particles are spherical or spherical-like and have an average particle size D.sub.S ranging from 0.9 to 2.4 m. The secondary particles have an average particle size D.sub.L ranging from 5 to 15 m. A value of D.sub.L/D.sub.S ranges from 5 to 16. The agglomeration-like multi-element cathode material has high energy density, good rate capability, and excellent cycle stability.

Disclosed are lithium-containing precursor material and a preparation method therefor, and lithium-ion cathode material, where the lithium-containing precursor material has a chemical formula of Li.sub.xM.sub.yD, M is at least one of Ni, Co, Mn, Al, or Mg, and D is one or more of CO.sub.3.sup.2, OH.sup., and C.sub.2O.sub.4.sup.2; a 2 diffraction angle of the lithium-containing precursor material has characteristic peaks in an XRD pattern of a Cu target K1, and the characteristic peaks P1 and P2 are 20-22 and 31-33, respectively, and an intensity ratio of the peaks (p1/p2) is 0<(p1/p2)10. Lithium and other metal elements in the lithium-containing precursor material achieve bulk molecular-level dispersion, such that neither batching nor mixing is required, ion migration resistance becomes small, sintering temperature is lowered, and the production costs are reduced. Moreover, lithium ion and metal salt have co-precipitation reaction, thereby reducing wastewater discharge by more than 30%.

Disclosed are lithium-containing precursor material and a preparation method therefor, and lithium-ion cathode material, where the lithium-containing precursor material has a chemical formula of Li.sub.xM.sub.yD, M is at least one of Ni, Co, Mn, Al, or Mg, and D is one or more of CO.sub.3.sup.2, OH.sup., and C.sub.2O.sub.4.sup.2; a 2 diffraction angle of the lithium-containing precursor material has characteristic peaks in an XRD pattern of a Cu target K1, and the characteristic peaks P1 and P2 are 20-22 and 31-33, respectively, and an intensity ratio of the peaks (p1/p2) is 0<(p1/p2)10. Lithium and other metal elements in the lithium-containing precursor material achieve bulk molecular-level dispersion, such that neither batching nor mixing is required, ion migration resistance becomes small, sintering temperature is lowered, and the production costs are reduced. Moreover, lithium ion and metal salt have co-precipitation reaction, thereby reducing wastewater discharge by more than 30%.

A method of preparing a positive electrode active material, a positive electrode and a rechargeable lithium battery are provided. The method of preparing the positive electrode active material includes mixing nickel-manganese-based composite hydroxide and a lithium raw material and subjecting them to primary heat treatment at about 200 C. to about 350 C. and secondary heat treatment at about 800 C. to about 1000 C.

A method of preparing a positive electrode active material, a positive electrode and a rechargeable lithium battery are provided. The method of preparing the positive electrode active material includes mixing nickel-manganese-based composite hydroxide and a lithium raw material and subjecting them to primary heat treatment at about 200 C. to about 350 C. and secondary heat treatment at about 800 C. to about 1000 C.

A high-voltage low-cobalt ternary positive electrode material has a general formula Li.sub.aNi.sub.bCo.sub.cMn.sub.dO.sub.2, where 0.97a1.1, 0.5b0.76, 0c0.1, 0.24d0.5, b+c+d=1, and c<0.35d. Compared with the prior art, the positive electrode material can be used at a higher voltage compared to other ternary positive electrode materials which have the same nickel content as the positive electrode material, such that the energy density is increased, and because the positive electrode material has a smaller change in size, the cracking and powdering of the positive electrode material are avoided, the service life of the material is prolonged, and the safety performance of the material is improved.

A high-voltage low-cobalt ternary positive electrode material has a general formula Li.sub.aNi.sub.bCo.sub.cMn.sub.dO.sub.2, where 0.97a1.1, 0.5b0.76, 0c0.1, 0.24d0.5, b+c+d=1, and c<0.35d. Compared with the prior art, the positive electrode material can be used at a higher voltage compared to other ternary positive electrode materials which have the same nickel content as the positive electrode material, such that the energy density is increased, and because the positive electrode material has a smaller change in size, the cracking and powdering of the positive electrode material are avoided, the service life of the material is prolonged, and the safety performance of the material is improved.