Secondary battery and electrical device
A secondary battery includes a positive electrode plate and a negative electrode plate; the positive electrode plate includes a positive electrode current collector and a positive electrode film layer arranged on at least one of the surfaces of the positive electrode current collector, the positive electrode film layer includes a positive electrode active material, the negative electrode plate includes a negative current collector and a negative electrode film layer arranged on at least one of the surfaces of the negative current collector, the negative electrode film layer includes a negative electrode active material; the secondary battery satisfies 0.15≤(1000*(B/A))/((T*D)*(n 2 /4))≤0.50, in which B/A represents the capacity-excess coefficient of the negative electrode of the secondary battery, dimensionless, T represents the thickness of the negative electrode film layer, in μm, and D represents the volume average particle size Dv50 of the negative electrode active material, in μm.
1 . A secondary battery, comprising:
a positive electrode plate comprising a positive electrode current collector and a positive electrode film layer which is arranged on at least one of surfaces of the positive electrode current collector and comprises a positive electrode active material; and
a negative electrode plate comprising a negative electrode current collector and a negative electrode film layer which is arranged on at least one of surfaces of the negative electrode current collector and comprises a negative electrode active material,
wherein the secondary battery satisfies 0.15≤(1000*(B/A))/((T*D)*(n 2 /4))≤0.50, in which
B/A represents a dimensionless capacity-excess coefficient of a negative electrode of the secondary battery,
T represents a thickness of the negative electrode film layer, in μm, and
D represents a volume average particle size (Dv50) of the negative electrode active material, in μm.
2 . The secondary battery according to claim 1 , wherein the secondary battery satisfies:
0.15
≤
(
1000
*
(
B
/
A
)
)
/
(
(
T
*
D
)
*
(
n
2
/
4
)
)
≤
0.4
;
or
0.2
≤
(
1000
*
(
B
/
A
)
)
/
(
(
T
*
D
)
*
(
n
2
/
4
)
)
≤
0.35
.
3 . The secondary battery according to claim 1 , wherein
the secondary battery, at at least one point of time T 0 during charging, has a charging current I 0 that is greater than or equal to n times of a nominal capacity,
wherein 2.8≤n, or, 4≤n≤8, or, 4≤n≤6 or 6≤n≤8.
4 . The secondary battery according to claim 1 , wherein
the secondary battery, during charging to from 10% state-of-charge to 70% state-of-charge, has an average charging current I τ that is greater than or equal to n times of a nominal capacity,
wherein 4<n, or, 4≤n≤8, or, 4≤n≤6 or 6≤n≤8;
or, the secondary battery, during charging to from 20% state-of-charge to 60% state-of-charge, has an average charging current I, that is greater than or equal to n times of the nominal capacity.
5 . The secondary battery according to claim 1 , wherein the secondary battery satisfies at least one of the following conditions from (1) to (3):
1.2
≤
B
/
A
≤
1.5
,
or
,
1.2
≤
B
/
A
≤
1.3
;
(
1
)
20
≤
T
≤
200
,
or
,
40
≤
T
≤
150
;
or
(
2
)
1
≤
D
≤
30
,
or
,
5
≤
D
≤
15.
(
3
)
6 . The secondary battery according to claim 1 , wherein the negative electrode film layer comprises:
a first film layer which comprises a first negative electrode active material and is arranged on a surface of the negative electrode current collector; and
a second film layer which comprises a second negative electrode active material and is arranged between the first film layer and the negative electrode current collector, and
wherein
the first negative electrode active material and the second negative electrode active material are one or more each independently selected from artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based material, tin-based material, and lithium titanate;
or, the first negative electrode active material and the second negative electrode active material are different materials; and
or, the first negative electrode active material comprises the artificial graphite, and the second negative electrode active material comprises the artificial graphite and the natural graphite.
7 . The secondary battery according to claim 6 , wherein the secondary battery satisfies 0≤T2*D2−T1*D1≤2000, in which
T1 represents the thickness of the first film layer, in μm,
T2 represents the thickness of the second film layer, in μm,
D1 represents the volume average particle size (Dv50) of the first negative electrode active material, in μm, and
D2 represents the volume average particle size (Dv50) of the second negative electrode active material, in μm.
8 . The secondary battery according to claim 7 , wherein the secondary battery satisfies at least one of the following conditions from (I) to (IV):
10
≤
T
1
≤
110
;
(
I
)
5
≤
D
1
≤
20
;
(
II
)
10
≤
T
2
≤
110
;
or
(
III
)
2
≤
D
2
≤
15.
(
IV
)
9 . The secondary battery according to claim 6 , wherein the secondary battery further satisfies V>V2, in which V represents an OI value of the negative electrode film layer, and V2 represents an OI value of the second film layer;
or
,
0.1
≤
V
≤
25
;
or
0.1
≤
V
2
≤
5.
10 . The secondary battery according to claim 1 , wherein
the positive electrode active material has a molecular formula of Li x A y Ni a Co b Mn c M (1-a-b-c) Y z , in which 0≤x≤2.1, 0≤y≤2.1, 0.9≤x+y≤2.1, 0≤a≤1, 0≤b≤1, 0≤c≤1, 0.1≤a+b+c≤1, and 1.8≤z≤3.5;
A is one or more selected from Na, K, and Mg; M is one or more selected from B, Mg, Al, Si, P, S, Ca, Sc, Ti, V, Cr, Fe, Cu, Zn, Sr, Y, Zr, Nb, Mo, Cd, Sn, Sb, Te, Ba, Ta, W, Yb, La, and Ce; and Y is one or more selected from O, and F.
11 . An electrical device, including a secondary battery, the secondary battery, comprising:
a positive electrode plate comprising a positive electrode current collector and a positive electrode film layer which is arranged on at least one of surfaces of the positive electrode current collector and comprises a positive electrode active material; and
a negative electrode plate comprising a negative electrode current collector and a negative electrode film layer which is arranged on at least one of surfaces of the negative electrode current collector and comprises a negative electrode active material,
wherein the secondary battery satisfies 0.15≤(1000*(B/A))/((T*D)*(n 2 /4))≤0.50, in which
B/A represents a dimensionless capacity-excess coefficient of a negative electrode of the secondary battery,
T represents a thickness of the negative electrode film layer, in μm, and
D represents a volume average particle size (Dv50) of the negative electrode active material, in μm.
12 . The electrical device according to claim 11 , wherein the secondary battery satisfies:
0.15
≤
(
1000
*
(
B
/
A
)
)
/
(
(
T
*
D
)
*
(
n
2
/
4
)
)
≤
0.4
;
or
0.2
≤
(
1000
*
(
B
/
A
)
)
/
(
(
T
*
D
)
*
(
n
2
/
4
)
)
≤
0.35
.
13 . The electrical device according to claim 11 , wherein
the secondary battery, at at least one point of time T 0 during charging, has a charging current I 0 that is greater than or equal to n times of a nominal capacity,
wherein 2.8<n, or, 4≤n≤8, or, 4≤n≤6 or 6≤n≤8.
14 . The electrical device according to claim 11 , wherein
the secondary battery, during charging to from 10% state-of-charge to 70% state-of-charge, has an average charging current I τ that is greater than or equal to n times of a nominal capacity,
wherein 4≤n, or, 4≤n≤8, or, 4≤n≤6 or 6≤n≤8;
or, the secondary battery, during charging to from 20% state-of-charge to 60% state-of-charge, has an average charging current I, that is greater than or equal to n times of the nominal capacity.
15 . The electrical device according to claim 11 , wherein the secondary battery satisfies at least one of the following conditions from (1) to (3):
1.2
≤
B
/
A
≤
1.5
,
or
,
1.2
≤
B
/
A
≤
1.3
;
(
1
)
20
≤
T
≤
200
,
or
,
40
≤
T
≤
150
;
or
(
2
)
1
≤
D
≤
30
,
or
,
5
≤
D
≤
15.
(
3
)
16 . The electrical device according to claim 11 , wherein the negative electrode film layer comprises:
a first film layer which comprises a first negative electrode active material and is arranged on a surface of the negative electrode current collector; and
a second film layer which comprises a second negative electrode active material and is arranged between the first film layer and the negative electrode current collector, and
wherein
the first negative electrode active material and the second negative electrode active material are one or more each independently selected from artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based material, tin-based material, and lithium titanate;
or, the first negative electrode active material and the second negative electrode active material are different materials; and
or, the first negative electrode active material comprises the artificial graphite, and the second negative electrode active material comprises the artificial graphite and the natural graphite.
17 . The electrical device according to claim 16 , wherein the secondary battery satisfies 0<T2*D2−T1*D1≤2000, in which
T1 represents the thickness of the first film layer, in μm,
T2 represents the thickness of the second film layer, in μm,
D1 represents the volume average particle size (Dv50) of the first negative electrode active material, in μm, and
D2 represents the volume average particle size (Dv50) of the second negative electrode active material, in μm.
18 . The electrical device according to claim 17 , wherein the secondary battery satisfies at least one of the following conditions from (I) to (IV):
10
≤
T
1
≤
110
;
(
I
)
5
≤
D
1
≤
20
;
(
II
)
10
≤
T
2
≤
110
;
or
(
III
)
2
≤
D
2
≤
15.
(
IV
)
19 . The electrical device according to claim 16 , wherein the secondary battery further satisfies V>V2, in which V represents an OI value of the negative electrode film layer, and V2 represents an OI value of the second film layer;
or
,
0.1
≤
V
≤
25
;
or
0.1
≤
V
2
≤
5.
20 . The electrical device according to claim 11 , wherein
the positive electrode active material has a molecular formula of Li x A y Ni a Co b Mn c M (1-a-b-c) Y z , in which 0≤x≤2.1, 0≤y≤2.1, 0.9≤x+y≤2.1, 0≤a≤1, 0≤b≤1, 0≤c≤1, 0.1<a+b+c≤1, and 1.8≤z≤3.5;
A is one or more selected from Na, K, and Mg; M is one or more selected from B, Mg, Al, Si, P, S, Ca, Sc, Ti, V, Cr, Fe, Cu, Zn, Sr, Y, Zr, Nb, Mo, Cd, Sn, Sb, Te, Ba, Ta, W, Yb, La, and Ce; and Y is one or more selected from O, and F.