POSITIVE ELECTRODE MATERIAL FOR SODIUM-ION BATTERY, PREPARATION METHOD THEREOF, AND SODIUM-ION BATTERY, BATTERY MODULE, BATTERY PACK AND APPARATUS ASSOCIATED THEREWITH

1 . A positive electrode material for a sodium-ion battery comprising a composite of sodium halophosphate with carbon having the following molecular formula:

Na 2 M1 h M2 k (PO 4 )X/C

in which M1 and M2 are transition metal ions each independently selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Sr, Y, Nb, Mo, Sn, Ba and W; h is from 0 to 1, k is from 0 to 1, and h+k=1; X is halogen ion selected from F, Cl and Br,

wherein the positive electrode material has a powder resistivity in the range of from 10 Ω·cm to 5,000 Ω·cm under a pressure of 12 MPa, optionally in the range of from 20 Ω·cm to 2,000 Ω·cm.

2 . The positive electrode material for the sodium-ion battery according to claim 1 , wherein the positive electrode material has a grain size in the range of from 0.01 micron to 20 micron, optionally in the range of from 0.05 micron to 5 micron.

3 . The positive electrode material for the sodium-ion battery according to claim 1 , wherein the positive electrode material has a carbon content in the range of from 0.05 wt % to 15 wt %.

4 . The positive electrode material for the sodium-ion battery according to claim 1 , wherein the carbon of the positive electrode material is derived from a carbon source comprising an inorganic carbon, an organic carbon or a combination thereof.

5 . The positive electrode material for the sodium-ion battery according to claim 4 , wherein the organic carbon is selected from one or more of glucose, fructose, sucrose, maltose, starch, cellulose, citric acid, ascorbic acid, glutamic acid, polypyrrole, polyaniline, polythiophene, poly(3,4-ethylenedioxythiophene), polystyrene sulfonate, polyphenylene sulfide and derivatives thereof.

6 . The positive electrode material for the sodium-ion battery according to claim 4 , wherein the inorganic carbon is selected from one or more of acetylene black, conductive carbon black, conductive graphite, Ketjen black, carbon nanotubes, carbon nanobelts, carbon fiber, graphene and carbon dots.

7 . A preparation method for preparing a positive electrode material for a sodium-ion battery, the positive electrode material comprises a composite of sodium halophosphate with carbon having the following molecular formula:

Na 2 M1 h M2 k (PO 4 )X/C

in which M1 and M2 are transition metal ions each independently selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Sr, Y, Nb, Mo, Sn, Ba and W; h is from 0 to 1, k is from 0 to 1, and h+k=1; X is halogen ion selected from F, Cl and Br,

the positive electrode material has a powder resistivity in the range of from 10 Ω·cm to 5,000 Ω·cm under a pressure of 12 MPa, optionally in the range of from 20 Ω·cm to 2,000 Ω·cm,

wherein the positive electrode material is obtained as follows:

i) sufficiently mixing materials for forming a composite of sodium halophosphate with carbon in the presence of a solvent to form a uniform powder; and

ii) thermally treating the uniform powder in an inert atmosphere and at a temperature of from 500° C. to 700° C. to form the positive electrode material.

8 . The preparation method of the positive electrode material for the sodium-ion battery according to claim 7 , wherein the mixing is carried out by ball mill, roll mill, centrifugal mill, stirring mill, jet mill, sand mill and Raymond mill.

9 . The preparation method of the positive electrode material for the sodium-ion battery according to claim 7 , wherein the solvent is selected from one or more of deionized water, methanol, ethanol, acetone, isopropanol, n-hexanol, dimethylformamide, ethylene glycol and diethylene glycol.

10 . A sodium-ion battery comprising a positive electrode, a negative electrode, a separator and an electrolytic solution, wherein the active material of the positive electrode comprises the positive electrode material according to claim 1 .

11 . A sodium-ion battery comprising a positive electrode, a negative electrode, a separator and an electrolytic solution, wherein the active material of the positive electrode comprises the positive electrode material prepared by the method according to claim 7 .