NEGATIVE ELECTRODE PLATE, SECONDARY BATTERY, BATTERY MODULE, BATTERY PACK, AND ELECTRIC APPARATUS

1 . A negative electrode plate, comprising:

a negative electrode current collector; and

active material layers disposed on at least one surface of the negative electrode current collector, the active material layers comprising:

a first active material layer comprising a first active material; and

a second active material layer disposed on a surface of the first active material layer and comprising a second active material;

wherein:

the active material layers satisfy α×CW 2 ≤CW 1 ;

α is a relative factor of layer spacings, wherein

α

=

d

⁢

2

d

⁢

1

and 1≤α≤1.12;

d 1 is a layer spacing corresponding to a d002 peak of the first active material, in units of nm;

d 2 is a layer spacing corresponding to a d002 peak of the second active material, in units of nm;

CW 1 is mass per unit area of the first active material layer disposed on the negative electrode current collector, in units of g/m 2 ; and

CW 2 is mass per unit area of the second active material layer disposed on the negative electrode current collector, in units of g/m 2 .

2 . The negative electrode plate according to claim 1 , wherein:

CW

⁢

1

CW

⁢

2

is inversely proportional to

d

⁢

1

×

Da

⁢

50

d

⁢

2

×

Db

⁢

50

,

and

0.2

≤

CW

⁢

2

CW

⁢

2

+

CW

⁢

1

≤

0.45

;

Da50 is a volume median particle size of the first active material, in units of μm; and

Db50 is a volume median particle size of the second active material, in units of μm.

3 . The negative electrode plate according to claim 2 , wherein the volume median particle size Da50 of the first active material and the volume median particle size Db50 of the second active material satisfy

0.2

≤

Db

⁢

50

Da

⁢

50

≤

0.8

.

4 . The negative electrode plate according to claim 1 , wherein the active material layers satisfy

CW

2

≥

3

17

⁢

α

×

CW

1

.

5 . The negative electrode plate according to claim 4 , wherein a volume median particle size Da50 of the first active material and a volume median particle size Db50 of the second active material satisfy

0.2

≤

Db

⁢

50

Da

⁢

50

≤

0.8

.

6 . The negative electrode plate according to claim 4 , wherein:

the layer spacing d 1 corresponding to the d002 peak of the first active material is within a range of 0.335-0.3362 nm, and the layer spacing d 2 corresponding to the d002 peak of the second active material is within a range of 0.3356-0.38 nm.

7 . The negative electrode plate according to claim 4 , wherein a volume median particle size Da50 of the first active material is within a range of 8-20 μm, and a volume median particle size Db50 of the second active material is within a range of 4-12 μm.

8 . The negative electrode plate according to claim 4 , wherein the mass per unit area CW 1 of the first active material layer disposed on the negative electrode current collector is within a range of 80-200 g/m 2 , and the mass per unit area CW 2 of the second active material layer disposed on the negative electrode current collector is within a range of 10-110 g/m 2 .

9 . The negative electrode plate according to claim 1 , wherein:

the first active material is a natural graphite or artificial graphite material, and/or

the second active material is an artificial graphite material.

10 . The negative electrode plate according to claim 1 , wherein:

soft carbon or hard carbon is contained in the first active layer and/or the second active layer.

11 . A secondary battery, comprising:

a negative electrode plate comprising:

a negative electrode current collector; and

active material layers disposed on at least one surface of the negative electrode current collector, the active material layers comprising:

a first active material layer comprising a first active material; and

a second active material layer disposed on a surface of the first active material layer and comprising a second active material;

wherein:

the active material layers satisfy α×CW 2 ≤CW 1 ;

α is a relative factor of layer spacings, wherein

α

=

d

⁢

2

d

⁢

1

and 1≤α≤1.12;

d 1 is a layer spacing corresponding to a d002 peak of the first active material, in units of nm;

d 2 is a layer spacing corresponding to a d002 peak of the second active material, in units of nm;

CW 1 is mass per unit area of the first active material layer disposed on the negative electrode current collector, in units of g/m 2 ; and

CW 2 is mass per unit area of the second active material layer disposed on the negative electrode current collector, in units of g/m 2 .

12 . A battery pack comprising the secondary battery according to claim 11 .

13 . An electric apparatus comprising the secondary battery according to claim 11 .

14 . A battery module comprising:

a secondary battery comprising a negative electrode plate comprising:

a negative electrode current collector; and

active material layers disposed on at least one surface of the negative electrode current collector, the active material layers comprising:

a first active material layer comprising a first active material; and

a second active material layer disposed on a surface of the first active material layer and comprising a second active material;

wherein:

the active material layers satisfy a α×CW 2 ≤CW 1 ;

α is a relative factor of layer spacings, wherein

α

=

d

⁢

2

d

⁢

1

and 1≤α≤1.12;

d 1 is a layer spacing corresponding to a d002 peak of the first active material, in units of nm;

d 2 is a layer spacing corresponding to a d002 peak of the second active material, in units of nm;

CW 1 is mass per unit area of the first active material layer disposed on the negative electrode current collector, in units of g/m 2 ; and

CW 2 is mass per unit area of the second active material layer disposed on the negative electrode current collector, in units of g/m2.