High rate lithium cobalt oxide positive electrode material and manufacturing method thereof

1. A high-rate lithium cobaltate cathode material for a liquid state lithium ion battery, the high-rate lithium cobaltate cathode material comprising lithium cobaltate with or without a doping element M and a fast ionic conductor Li α M′ γ O β , wherein:

an element M′ in Li α M′ γ O β is one or more of Ti, Zr, Y, V, Nb, Mo, Sn, In, La, or W, 1≤α≤4, 1≤γ≤5, and 2≤β≤12,

the lithium cobaltate with or without the doping element M is represented by Li 1+y Co 1−x M x O 2 , the doping element M is one or more of Mg, Al, Si, Sc, Ni, Mn, Ga, or Ge, 0≤x≤0.1, and −0.01≤y≤0.01,

the high-rate lithium cobaltate cathode material is represented by a chemical formula of Li 1+y Co 1−x M x O 2 •zLi α M′ γ O β , and 0.005≤z≤0.01,

the high-rate lithium cobaltate cathode material comprises a multi-channel network formed by the fast ionic conductor Li α M′ γ O β ,

the lithium cobaltate with or without the doping element M, as primary particles, is melted integrally with the fast ionic conductor Li α M′ γ O β so as to form secondary particles, and the lithium cobaltate with or without the doping element M is embedded in the multi-channel network formed by the fast ionic conductor Li α M′ γ O β .

2. A method for preparing a high-rate lithium cobaltate cathode material comprising lithium cobaltate with or without a doping element M and a fast ionic conductor Li α M′ γ O β , wherein:

an element M′ in Li α M′ γ O β is one or more of Ti, Zr, Y, V, Nb, Mo, Sn, In, La, or W, 1≤α≤4, 1≤γ≤5, and 2≤β≤12,

the lithium cobaltate with or without the doping element M is represented by Li 1+y Co 1−x M x O 2 , the doping element M is one or more of Mg, Al, Si, Sc, Ni, Mn, Ga, or Ge, 0≤x≤0.1, and −0.01≤y≤0.01,

the high-rate lithium cobaltate cathode material comprises a multi-channel network formed by the fast ionic conductor Li α M′ γ O β ,

the lithium cobaltate with or without the doping element M, as primary particles, is melted integrally with the fast ionic conductor Li α M′ γ O β so as to form secondary particles,

the lithium cobaltate with or without the doping element M is embedded in the multi-channel network formed by the fast ionic conductor Li α M′ γ O β , and

the method comprises:

mixing cobaltous oxide impregnated with a hydroxide of the element M′ and a lithium source to obtain a homogenous mixture; and

sintering the homogenous mixture in an air atmosphere furnace at a high temperature, or

mixing cobaltous oxide impregnated with a hydroxide of the element M′, a lithium source and an additive containing the doping element M to obtain a homogenous mixture; and

sintering the homogenous mixture in an air atmosphere furnace at a high temperature.

3. The method according to claim 2 , wherein the method further comprises the following steps to obtain the cobaltous oxide impregnated with the hydroxide of the element M′:

dissolving an organic compound containing the element M′ in anhydrous ethanol under stirring to obtain a solution;

adding a porous cobalt oxide into the solution;

dispersing the porous cobalt oxide into the solution with a disperser for 0.5-1 h;

adding an aqueous ethanol solution with a volume ratio of ethanol to water of 5 to 20 and stirring for 2 to 5 h;

filtering under vacuum to obtain a first filter cake; and

drying the first filter cake to obtain the cobaltous oxide impregnated with the hydroxide of the element M′.

4. The method according to claim 3 , wherein:

the method further comprises pre-sintering a precursor to obtain the porous cobalt oxide,

the porous cobalt oxide has a porosity of 0.5% to 5%,

the porous cobalt oxide has an average pore size ranging from 100 nm to 500 nm,

the precursor is CoCO 3 .αH 2 O or CoC 2 O 4 .αH 2 O, and 0 ≤α≤9, and

the organic compound containing the element M′ is one or more of an alkoxide of the element M′, an alkyl compound of the element M′, a carbonyl compound of the element M′, or a carboxyl compound of the element M′.

5. The method according to claim 4 , wherein the method further comprises the following steps to obtain the porous cobalt oxide:

injecting a part of a precipitant solution with a pH of 6-14 into a reaction kettle;

simultaneously adding a cobalt salt solution, a complexing agent solution and a remaining part of the precipitant solution into the reaction kettle by parallel flows, under stirring and protection of an inert gas, such that a reaction mixture is formed and a reaction starts, wherein the reaction is performed at a pH of 6-14 and at a temperature of 0° C. to 85° C.;

aging the reaction mixture after the cobalt salt solution is completely added into the reaction kettle;

filtering the reaction mixture to obtain a second filter cake;

drying the second filter cake to obtain the precursor;

subjecting the precursor to the pre-sintering in an air atmosphere furnace; and

sieving the pre-sintered precursor to obtain the porous cobalt oxide.

6. The method according to claim 5 , wherein:

the cobalt salt solution is a solution formed by dissolving at least one of CoCl 2 .bH 2 O, CoSO 4 .bH 2 O, or Co(NO 3 ) 2 .bH 2 O in water, and 0≤b≤6,

a concentration of Co 2+ in the cobalt salt solution is 70-200 g/L,

the complexing agent solution is an ammonia water or an aminocarboxylate solution, and the precipitant solution is a carbonate solution, an oxalic acid, or an oxalate solution.

7. The method according to claim 5 wherein:

an aging time for aging the reaction mixture after the cobalt salt solution is completely added into the reaction kettle is 4 to 8 hours, and

the subjecting the precursor to the pre-sintering in an air atmosphere furnace comprises firstly sintering at 300° C. to 500° C. for 2 to 5 hours, and then sintering at 700° C. to 800° C. for 2 to 5 hours.

8. The method according to claim 2 , wherein:

the lithium source is one or more of lithium carbonate, lithium hydroxide, or lithium oxide, and

the additive containing the doping element M is at least one of oxide, hydroxide, carboxylate, carbonate, or basic carbonate of the doping element M.

9. The method according to claim 2 , wherein the sintering is performed at 850° C. to 1000° C. for 6 to 20 hours.