Positive electrode material of secondary battery and preparation method thereof
View Patent ↗The present disclosure provides a positive electrode material comprising: a positive electrode active material mixture comprising a positive electrode active material prepared with an active material precursor and a lithium compound, a conductive agent and a binder; and an active material precursor as an additive, in which the active material precursor as the additive is a same substance as the active material precursor as a material of the positive electrode active material.
1. A positive electrode material for a secondary lithium battery comprising:
a positive electrode active material mixture comprising a positive electrode active material prepared from an active material precursor and a lithium compound, a conductive agent, and a binder; and
an active material precursor as an additive,
wherein the active material precursor as the additive is a same substance as the active material precursor as a material of the positive electrode active material, and
the active material precursor is nickel-cobalt-manganese complex oxide precursor,
wherein
the nickel-cobalt-manganese complex oxide precursor has a composition of Formula 4 below:
M y P [Formula 4]
where, M=M′ 1−k A k , M′ is Ni 1−a−b (Ni 1/2 Mn 1/2 ) a Co b , 0.65≤a+b≤0.85, 0.1≤b≤0.4, A is a dopant, 0≤k≤0.05, 0.95≤y≤1.05, and P is one or more selected from the group consisting of —OH, —OOH, and —CO 3 , and
the positive electrode active material has a composition of formula LiM y O 2 , where M and y are same as M and y in the above Formula 4.
2. The positive electrode material of claim 1 , wherein the lithium compound is one, or two or more selected from the group consisting of lithium carbonate (Li 2 CO 3 ), lithium hydroxide (LiOH), lithium nitrate (LiNO 3 ), and lithium hydrate (LiOHH 2 O).
3. The positive electrode material of claim 1 , wherein the positive electrode active material mixture comprises 80.0-99.0 wt % positive electrode active material, 0.1-30.0 wt % conductive agent, and 0.1-30.0 wt % binder, and the positive electrode material comprises 1.0-5.0 wt % active material precursor as an additive, over a total weight of the positive electrode active material mixture.
4. The positive electrode material of claim 3 , wherein the positive electrode active material mixture comprises 92.0-97.0 wt % positive electrode active material, 1.0-5.0 wt % conductive agent, and 1.0-5.0 wt % binder, and the positive electrode material comprises 2.0-4.0 wt % active material precursor as an additive, over a total weight of the positive electrode active material mixture.
5. A method for preparing the positive electrode material of claim 1 , comprising steps of:
(a) preparing a positive electrode active material with an active material precursor and a lithium compound; and
(b) mixing the prepared positive electrode active material, a conductive agent, a binder, and an active material precursor as an additive.
6. The method of claim 5 , wherein the active material precursor as the additive at step (b) is added together with the positive electrode active material and mixed, when the positive electrode active material is added.
7. A positive electrode comprising the positive electrode material of claim 1 .
8. A secondary battery comprising the positive electrode of claim 7 .