Positive electrode for a lithium battery
A method for producing a lithium alkali transition metal oxide for use as a positive electrode material for lithium secondary batteries by a precipitation method. The positive electrode material is a lithium alkali transition metal composite oxide and is prepared by mixing a solid state mixed with alkali and transition metal carbonate and a lithium source. The mixture is thermally treated to obtain a small amount of alkali metal residual in the lithium transition metal composite oxide cathode material.
1. A cathode material of general formula
x LiA a′ Ni α Co β Mn γ Mo δ M y O 2 .(1 −x )Li 2 Mn y O 3
wherein:
the LiA a′ Ni α Co β Mn γ Mo δ M y O 2 and Li 2 Mn γ O 3 components form a layered structure;
A is Na, K, or a mixture of Na and K;
M is Mg, Zn, Al, Ga, B, Zr, Si, Ti, Nb, W, or a mixture of any two or more thereof;
X is F, S, Cl, I, or a mixture of any two or more thereof;
x ranges from 0 to 1;
a′ ranges from 0.01 to about 0.1;
α ranges from 0.01 to 1;
β ranges from 0 to 1;
γ ranges from 0.01 to 1;
δ ranges from 0 to 0.2; and
y ranges from 0 to 0.15.
2. The cathode material of claim 1 , wherein A is Na.
3. The cathode material of claim 1 , wherein α is 1, A is Na.
4. The cathode material of claim 1 , wherein the material comprises a plurality of primary particles of less than about 300 nm in size and a plurality of nano-sized particles having an average secondary diameter of less than about 100 microns.
5. A rechargeable secondary battery electrode, comprising the cathode material of claim 1 .
6. A positive electrode comprising a cathode material of general formula
x LiA a′ Ni α Co β Mn γ Mo δ M y O 2 .(1 −x )Li 2 Mn γ O 3
wherein:
the LiA a′ Ni α Co β Mn γ Mo δ M y O 2 and Li 2 Mn γ O 3 components form a layered structure;
A is Na, K, or a mixture of Na and K;
M is Mg, Zn, Al, Ga, B, Zr, Si, Ti, Nb, W, or a mixture of any two or more thereof;
X is F, S, Cl, I, or a mixture of any two or more thereof;
x ranges from 0 to 1;
a′ ranges from 0.01 to about 0.1;
α ranges from 0.01 to 1;
β ranges from 0 to 1;
γ ranges from 0.01 to 1;
δ ranges from 0 to 0.2; and
y ranges from 0 to 0.15.
7. The positive electrode of claim 6 , wherein A is Na.
8. The positive electrode of claim 6 , wherein α is 1, A is Na.
9. The positive electrode of claim 8 , wherein the cathode material comprises a plurality of primary particles of less than about 300 nm in size and a plurality of nano-sized particles having an average secondary diameter of less than about 100 microns.