Lithium and manganese rich positive active material compositions
A positive electrode active material may include a compound represented by formula 1 or formula 2: Li (1.333−0.667x−y) Mn (0.667−0.333x) Ni x A (y−a) M a O 2 (1), Li (1.333−0.667x−z−a) Mn (0.667−0.333x−0.5y) Ni (x−0.5y+z) A (y+a−b) M b O 2 (2). A is Co, Cr, or a combination thereof, M is W +6 , Ta +5 , V +5 , or a combination thereof, 0<x<0.5, 0<y<0.333, 0<x<0.04, 0<x−0.5y+z<0.5, 0<y+a−b<0.333, and 0<b<0.04.
1 . A positive electrode active material comprising a compound represented by formula 1:
Li
(
1.333
-
0.667
x
-
y
)
Mn
(
0.667
-
0.333
x
)
Ni
x
A
(
y
-
a
)
M
a
O
2
(
1
)
wherein:
A is Co, Cr, or a combination thereof;
M is W +6 , Ta +5 , V +5 , or a combination thereof;
0<x<0.5;
0<y<0.333; and
0<a<0.04.
2 . The positive electrode active material of claim 1 , wherein 0.2<x<0.35.
3 . The positive electrode active material of claim 1 , wherein 0.04<y<0.09.
4 . The positive electrode active material of claim 1 , wherein 0<a<0.02.
5 . The positive electrode active material of claim 1 includes a material selected from the group consisting of Li 1.12 Mn 0.59 Ni 0.23 Co 0.05 W 0.01 O 2 , Li 1.12 Mn 0.59 Ni 0.23 Co 0.05 Ta 0.01 O 2 , Li 1.12 Mn 0.59 Ni 0.23 Co 0.05 V 0.01 O 2 , Li 1.10 Mn 0.59 Ni 0.23 Co 0.07 W 0.01 O 2 , Li 1.10 Mn 0.59 Ni 0.23 Co 0.07 Ta 0.01 O 2 , and Li 1.10 Mn 0.59 Ni 0.23 Co 0.07 V 0.01 O 2 .
6 . The positive electrode active material of claim 1 , wherein the Mn has an average oxidation state in the range of 3.65 to 3.8.
7 . A positive electrode active material comprising a compound represented by formula 2:
Li
(
1.333
-
0.667
x
-
z
-
a
)
Mn
(
0.667
-
0.333
x
-
0.5
y
)
Ni
(
x
-
0.5
y
+
z
)
A
(
y
+
a
-
b
)
M
b
O
2
(
2
)
wherein:
A is Co, Cr, or a combination thereof;
M is W +6 , Ta +5 , V +5 , or a combination thereof;
0<x−0.5y+z<0.5;
0<y+a−b<0.333; and
0<b<0.04.
8 . The positive electrode active material of claim 7 , wherein 0.2<x−0.5y+z<0.37.
9 . The positive electrode active material of claim 7 , wherein 0<y+a−b<0.09.
10 . The positive electrode active material of claim 7 , wherein 0<b<0.02.
11 . The positive electrode active material of claim 7 includes a material selected from the group consisting of Li 1.12 Mn 0.57 Ni 0.24 Co 0.06 W 0.01 O 2 , Li 1.12 Mn 0.57 Ni 0.24 Co 0.06 Ta 0.01 O 2 , Li 1.12 Mn 0.57 Ni 0.24 Co 0.06 V 0.01 O 2 , Li 1.10 Mn 0.57 Ni 0.25 Co 0.07 W 0.01 O 2 , Li 1.10 Mn 0.57 Ni 0.25 Co 0.07 Ta 0.01 O 2 , and Li 1.10 Mn 0.57 Ni 0.25 Co 0.07 V 0.01 O 2 .
12 . The positive electrode active material of claim 7 , wherein the Mn has an average oxidation state in the range of 3.7 to 3.85.
13 . A rechargeable lithium-ion battery comprising at least one lithium-ion battery cell, each lithium-ion battery cell including:
a positive electrode comprising a compound represented by formula 1 or formula 2:
Li
(
1.333
-
0.667
x
-
y
)
Mn
(
0.667
-
0.333
x
)
Ni
x
A
(
y
-
a
)
M
a
O
2
(
1
)
Li
(
1.333
-
0.667
x
-
z
-
a
)
Mn
(
0.667
-
0.333
x
-
0.5
y
)
Ni
(
x
-
0.5
y
+
z
)
A
(
y
+
a
-
b
)
M
b
O
2
(
2
)
wherein:
A is Co, Cr, or a combination thereof,
M is W +6 , Ta +5 , V +5 , or a combination thereof,
0<x<0.5,
0<y<0.333,
0<a<0.04,
0<x−0.5y+z<0.5,
0<y+a−b<0.333, and
0<b<0.04;
a negative electrode including a negative active material; and
an electrolyte contacting the positive electrode and the negative electrode.
14 . The rechargeable lithium-ion battery of claim 13 , wherein 0.2<x<0.35.
15 . The rechargeable lithium-ion battery of claim 13 , wherein 0.04<y<0.09.
16 . The rechargeable lithium-ion battery of claim 13 , wherein 0<a<0.02.
17 . The rechargeable lithium-ion battery of claim 13 , wherein 0.2<x−0.5y+z<0.37.
18 . The rechargeable lithium-ion battery of claim 13 , wherein 0<y+a−b<0.09.
19 . The rechargeable lithium-ion battery of claim 13 , wherein 0<b<0.02.
20 . The rechargeable lithium-ion battery of claim 13 includes a material selected from the group consisting of Li 1.12 Mn 0.59 Ni 0.23 Co 0.05 W 0.01 O 2 , Li 1.12 Mn 0.59 Ni 0.23 Co 0.05 Ta 0.01 O 2 , Li 1.12 Mn 0.59 Ni 0.23 Co 0.05 V 0.01 O 2 , Li 1.10 Mn 0.59 Ni 0.23 Co 0.07 W 0.01 O 2 , Li 1.10 Mn 0.59 Ni 0.23 Co 0.07 Ta 0.01 O 2 , Li 1.10 Mn 0.59 Ni 0.23 Co 0.07 V 0.01 O 2 , Li 1.12 Mn 0.57 Ni 0.24 Co 0.06 W 0.01 O 2 , Li 1.12 Mn 0.57 Ni 0.24 Co 0.06 Ta 0.01 O 2 , Li 1.12 Mn 0.57 Ni 0.24 Co 0.06 V 0.01 O 2 , Li 1.10 Mn 0.57 Ni 0.25 Co 0.07 W 0.01 O 2 , Li 1.10 Mn 0.57 Ni 0.25 Co 0.07 Ta 0.01 O 2 , and Li 1.10 Mn 0.57 Ni 0.25 Co 0.07 V 0.01 O 2 .