MODIFIED LITHIUM-RICH MANGANESE-BASED MATERIAL, MODIFICATION METHOD OF LITHIUM-RICH MANGANESE-BASED MATERIAL, SECONDARY BATTERY AND ELECTRICAL DEVICE

1 . A modified lithium-rich manganese-based material, comprising:

a lithium-rich manganese-based material co-doped with anion and cation, the lithium-rich manganese-based material having a chemical formula of xLi 2 MnO 3 ·(1−x)LiNi y Co z Mn a O 2 , where 0<x<1, 0≤y≤1, 0≤z≤1, and y+z+a=1; and

a fast ionic conductor material attached to the lithium-rich manganese-based material co-doped with anion and cation, the fast ionic conductor material being selected from at least one of a group consisting of LATP, LAGP, LLZO, LLTO, LiBO 2 , LiAlO 2 , and LiPO 3 ,

wherein the doped cation element M1 is selected from at least one of a group consisting of Na, Fe, Nb, Ti, Mg, Al, Cr, and Er, and the doped anion element M2 is selected from at least one of a group consisting of F, Cl, Br, I, S, B, P, N, Se, and Te.

2 . The modified lithium-rich manganese-based material according to claim 1 , wherein a doping amount of the doped cation element M1/a doping amount of the doped anion element M2 is 1:(0.3˜2), optionally 1:(0.5˜1.5); and

optionally, when the doped cation element M1 is Fe, the doped anion element M2 is Cl; or when the doped cation element M1 is Na, the doped anion element M2 is F.

3 . The modified lithium-rich manganese-based material according to claim 1 , wherein the doping amount of the doped cation element M1 is in a range of 1000 ppm to 20000 ppm, optionally 2000 ppm to 10000 ppm; and

the doping amount of the doped anion element M2 is in a range of 300 ppm to 40000 ppm, optionally 1000 ppm to 20000 ppm.

4 . The modified lithium-rich manganese-based material according to claim 1 , wherein a weight content of the fast ionic conductor material in the modified lithium-rich manganese-based material is in a range of 2000 ppm to 20000 ppm, optionally 2000 ppm to 10000 ppm.

5 . The modified lithium-rich manganese-based material according to claim 1 , wherein the modified lithium-rich manganese-based material has a conductivity in a range of 10 μS/cm to 60 μS/cm, preferably 30 μS/cm to 60 μS/cm.

6 . The modified lithium-rich manganese-based material according to claim 1 , wherein the modified lithium-rich manganese-based material has a specific surface area smaller than 3.2 m 2 /g.

7 . The modified lithium-rich manganese-based material according to claim 1 , wherein a volume particle size distribution diameter of the modified lithium-rich manganese-based material satisfies (D v90 −D v10 )/D v50 ≥1.1.

8 . The modified lithium-rich manganese-based material according to claim 1 , wherein in an X-ray diffraction spectrum of the modified lithium-rich manganese-based material, a peak area ratio of I003/I104 is in a range of 1.0 to 1.2; a peak area ratio of I020/(I003+I104) is in a range of 0.005 to 0.05.

9 . A modification method of a lithium-rich manganese-based material, comprising:

obtaining a lithium-rich manganese-based material co-doped with anion and cation by performing a first sintering on a first mixture, the first mixture comprising a lithium-rich manganese-based precursor, a lithium salt, a substance containing a cation element M1, and a substance containing an anion element M2, and the lithium-rich manganese-based material having a chemical formula of xLi 2 MnO 3 ·(1−x)LiNi y Co z Mn a O 2 , where 0<x<1, 0≤y≤1, 0≤z≤1, and y+z+a=1; and

obtaining a modified lithium-rich manganese-based material by performing a second sintering on a second mixture, the second mixture comprising a fast ionic conductor material and the lithium-rich manganese-based material co-doped with anion and cation, and the modified lithium-rich manganese-based material comprising the lithium-rich manganese-based material co-doped with anion and cation and the fast ionic conductor material,

wherein the cation element M1 is selected from at least one of a group consisting of Na, Fe, Nb, Ti, Mg, Al, Cr, and Er, the anion element M2 being selected from at least one of a group consisting of F, Cl, Br, I, S, B, P, N, Se, and Te, and a mass ratio of the cation element M1 to the anion element M2 being 1:(0.3˜2); and

wherein the fast ionic conductor material is selected from at least one of a group consisting of LATP, LAGP, LLZO, LLTO, LiBO 2 , LiAlO 2 , and LiPO 3 .

10 . The modification method according to claim 9 , wherein the lithium-rich manganese-based precursor has a chemical formula of Ni b Co c Mn 1−b−c (OH) 2 , where 0.05≥c≥0 and 0.4≥b>0.

11 . The modification method according to claim 9 , wherein the substance containing the cation element M1 is an oxide of M1 or a salt of M1.

12 . The modification method according to claim 9 , wherein the first sintering comprises a first-stage sintering process and a second-stage sintering process;

a sintering temperature of the first-stage sintering process is in a range of 400° C. to 600° C., a heat preservation time is in a range of 4 h to 8 h; and

a sintering temperature of the second-stage sintering process is in a range of 800° C. to 1000° C., a heat preservation time is in a range of 10 h to 20 h.

13 . The modification method according to claim 9 , wherein in the second sintering, a sintering temperature is in a range of 500° C. to 700° C., a heat preservation time is in a range of 4 h to 8 h.

14 . A secondary battery, comprising:

a positive electrode plate comprising a positive electrode film layer, the positive electrode film layer comprising a positive electrode active material;

a separator; and

a negative electrode plate,

wherein the positive electrode active material comprises the modified lithium-rich manganese-based material according to claim 1 .

15 . An electrical device, comprising the secondary battery according to claim 14 .