Coatings for cathode active materials
A cathode active material includes a plurality of cathode active compound particles and a coating disposed over each of the cathode active compound particles. The coating includes a lithium (Li)-ion conducting oxide containing lanthanum (La) and titanium (Ti).
1. A cathode active material comprising:
a plurality of cathode active compound particles comprising a compound of Formula (X):
Li α Co 1·x·y M y Mn x O δ (X)
wherein
M is selected from La, Ge, B, Na, Mg, Ti, Ca, V, Cr, Fe, Co, Ni, Cu, Zn, Al, Sc, Y, Ga Zr, Ru and Mo;
0.95≤α≤1.05;
0<x≤0.30;
0≤y≤0.10; and
1.98<δ<2.04; and
a coating disposed over the entirety of each of the cathode active compound particles;
the coating comprising a lithium (Li)-ion conducting oxide comprising lanthanum (La) and titanium (Ti).
2. The cathode active material of claim 1 , wherein the coating comprises a Perovskite La 2/3·x Li 3x TiO 3 , where 0≤x≤2/3.
3. The cathode active material of claim 1 , wherein the coating is less than 1% of the particles by weight.
4. The cathode active material of claim 1 , wherein the coating comprises a blend of the lithium-ion conducting oxide containing La and Ti having a molar ratio of Li to Ti from 0.03 to 0.5 and a molar ratio of Li to La from 0.05 to 1 and an electrically conductive material.
5. The cathode active material of claim 1 , wherein the cathode active material comprises lithium cobalt oxides or lithium transition-metal oxides.
6. The cathode active material of claim 1 , wherein the cathode active compound particles comprise a compound of Formula (IXb)
(v) [Li 2 M 7 O 3 ]·(1-v) [Li a Co 1−δ M 8 σ O 2 ] (IXb)
wherein
M 7 is selected from Mn, Ti, Zr, and Ru;
M 8 is selected from La, Ge, B, Na, Mg, Ti, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, Sc, Y, Ga, Zr, Ru, and Mo;
0.95≤α≤1.05;
0.01<v<0.10; and
0<σ≤0.05.
7. The cathode active material of claim 6 , wherein 0.95≤a<0.99.
8. The cathode active material of claim 6 , wherein M 8 is selected from Na, Mg, Ti, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, Sc, Y, Ga, Zr, Ru, and Mo.
9. The cathode active material of claim 1 , wherein 0.95≤a≤0.99.
10. A cathode comprising the coated cathode active material of claim 1 .
11. A battery cell, comprising:
an anode comprising an anode current collector, the cathode comprising the coated cathode active material of claim 1 ; and
a separator disposed between the anode and the cathode.
12. The battery cell of claim 11 , having an average voltage of greater than 4.0 V after 5 cycles of charge and discharge.