LITHIUM COMPOUND, NICKEL-BASED CATHODE ACTIVE MATERIAL, METHOD FOR PREPARING LITHIUM OXIDE, METHOD FOR PREPARING NICKEL-BASED CATHODE ACTIVE MATERIAL, AND SECONDARY BATTERY USING SAME
The present invention relates to a lithium compound, a nickel-based cathode active material, a method for preparing lithium oxide, a method for preparing a nickel-based cathode active material, and a secondary battery using same. The lithium compound includes primary particles of Li 2 O having an average particle diameter (D50) of less than or equal to 5 μm; and secondary particles composed of the primary particles.
1 . A lithium compound, comprising
Li 2 O primary particles having an average particle diameter (D50) of less than or equal to 5 μm; and
secondary particles composed of the primary particles.
2 . The lithium compound of claim 1 , wherein the secondary particle has a spherical shape.
3 . The lithium compound of claim 1 , wherein the average particle diameter (D50) of the secondary particles is 10 to 100 μm.
4 . The lithium compound of claim 3 , wherein the average particle diameter (D50) of the secondary particles is 10 to 30 μm.
5 . A nickel-based cathode active material derived from a lithium compound including primary Li 2 O particles having an average particle diameter (D50) of less than or equal to 5 μm and secondary particles composed of the primary particles; and a nickel raw material.
6 . The nickel-based cathode active material of claim 5 , wherein the cathode active material is Li 2 NiO 2 , and Dmin is greater than or equal to 5 μm.
7 . The nickel-based cathode active material of claim 6 , wherein the cathode active material comprises a residual lithium compound of less than or equal to 2.5 wt % based on 100 wt % of the total weight.
8 . A method for preparing lithium oxide, comprising
reacting hydrogen peroxide (H 2 O 2 ) and lithium hydroxide (LiOH) to obtain over-lithiated oxide (Li 2 O 2 ); and
heat-treating the over-lithiated oxide to obtain lithium oxide (Li 2 O),
wherein in the reacting of the hydrogen peroxide (H 2 O 2 ) and lithium hydroxide (LiOH) to obtain a over-lithiated oxide (Li 2 O 2 ),
a mole ratio (Li/H 2 O 2 ) of lithium of lithium hydroxide to hydrogen peroxide is 1.9 to 2.4.
9 . The method of claim 8 , wherein
in the reacting of the hydrogen peroxide (H 2 O 2 ) and lithium hydroxide (LiOH) to obtain a over-lithiated oxide (Li 2 O 2 ),
the reaction temperature is 40 to 60° C.
10 . The method of claim 8 , wherein
in the reacting of hydrogen peroxide (H 2 O 2 ) and lithium hydroxide (LiOH) to obtain over-lithiated oxide (Li 2 O 2 ),
the reaction of hydrogen peroxide (H 2 O 2 ) and lithium hydroxide (LiOH) is accompanied by stirring at 500 rpm or more.
11 . The method of claim 8 , wherein
the heat-treating of the over-lithiated oxide to obtain lithium oxide (Li 2 O) is performed at 400 to 600° C. in an inert atmosphere.
12 . A method for preparing a nickel-based cathode active material, comprising
reacting hydrogen peroxide (H 2 O 2 ) and lithium hydroxide (LiOH) to obtain over-lithiated oxide (Li 2 O 2 );
heat-treating the over-lithiated oxide to obtain lithium oxide (Li 2 O); and
firing the lithium oxide and nickel raw material to obtain a nickel-based cathode active material;
wherein in the reacting of the hydrogen peroxide (H 2 O 2 ) and lithium hydroxide (LiOH) to obtain a over-lithiated oxide (Li 2 O 2 ),
a mole ratio (Li/H 2 O 2 ) of lithium of lithium hydroxide to hydrogen peroxide is 1.9 to 2.4.
13 . (canceled)