Negative electrode plate, secondary battery, battery module, battery pack, and power consuming device

1 . A negative electrode plate, characterized in that,

the negative electrode plate comprises a main body region and at least one low-thermal-conductivity edge region;

the low-thermal-conductivity edge region and the main body region respectively have thermal conductivities of λ 2 and λ 1 , where λ 2 <λ 1 ; and

the negative electrode plate comprises a current collector layer and an active material layer, wherein

a priming coat belonging to the low-thermal-conductivity edge region is further provided between the current collector layer belonging to the low-thermal-conductivity edge region and the active material layer belonging to the low-thermal-conductivity edge region;

a priming coat belonging to the main body region is further provided between the current collector layer belonging to the main body region and the active material layer belonging to the low-thermal-conductivity edge region; and

the priming coat belonging to the low-thermal-conductivity edge region and the priming coat belonging to the main body region respectively have thermal conductivities of λ 22 and λ 12 , where λ 22 <λ 12 .

2 . The negative electrode plate according to claim 1 , characterized by any one of the following:

(1) a ratio λ 1 /λ 2 of λ 1 to λ 2 being 1.1-1.5:1;

(2) λ 1 having a value of 300-400 W/(m·K);

(3) λ 2 having a value of 200-300 W/(m·K).

3 . The negative electrode plate according to claim 1 , wherein the low-thermal-conductivity edge region and the main body region respectively have electrical conductivities of σ 2 and σ 1 ; and

the negative electrode plate meets a kinetic coefficient Q>0, and the kinetic coefficient Q is calculated by using the following formula:

Q

=

λ

2

-

λ

1

λ

2

-

1.2

(

σ

2

-

σ

1

)

σ

2

.

4 . The negative electrode plate according to claim 1 , characterized by any one of the following:

(1) a ratio σ 1 /σ 2 of σ 1 to σ 2 being 1.3 or less;

(2) σ 1 having a value of 5.3×10 7 -5.9×10 7 μS·cm −1 ;

(3) σ 2 having a value of 5.0×10 7 -5.3×10 7 μS·cm −1 .

5 . The negative electrode plate according to claim 1 , characterized in that, the negative electrode plate comprises a current collector layer; and

the current collector layer belonging to the low-thermal-conductivity edge region and the current collector layer belonging to the main body region respectively have thermal conductivities of λ 21 and λ 11 , where λ 21 <λ 11 .

6 . The negative electrode plate according to claim 1 , characterized in that, the negative electrode plate comprises an active material layer; and

the negative electrode active material layer belonging to the low-thermal-conductivity edge region and the negative electrode active material layer belonging to the main body region respectively have thermal conductivities of λ 23 and λ 13 , where λ 23 <λ 13 .

7 . The negative electrode plate according to claim 1 , characterized in that, the priming coat belonging to the low-thermal-conductivity edge region comprises a thermal resistance material, the priming coat belonging to the main body region comprises conductive carbon black, and the thermal resistance material has a thermal conductivity less than that of the conductive carbon black.

8 . The negative electrode plate according to claim 7 , characterized in that,

the priming coat belonging to the main body region does not comprise the thermal resistance material; or

the priming coat belonging to the main body region comprises the thermal resistance material, but the content of the thermal resistance material in the priming coat belonging to the main body region is less than that in the priming coat belonging to the low-thermal-conductivity edge region.

9 . The negative electrode plate according to claim 7 , characterized in that, the thermal resistance material is selected from one or more of the following: gelatin, ammonium sulfate, ammonium chloride, thiourea, and copper chloride.

10 . The negative electrode plate according to claim 1 , characterized in that, the priming coat belonging to the main body region comprises the following components:

60 wt %-70 wt % of conductive carbon black; and

30 wt %-40 wt % of binder.

11 . The negative electrode plate according to claim 1 , wherein the negative electrode plate comprises a first low-thermal-conductivity edge region and/or a second low-thermal-conductivity edge region, and the main body region comprises a first long side and a second long side which are parallel to each other;

the first low-thermal-conductivity edge region is located outside the first long side of the main body region; and

the second low-thermal-conductivity edge region is located outside the second long side of the main body region.

12 . The negative electrode plate according to claim 1 , wherein the negative electrode plate features one or more of the following:

(1) an outer side of the low-thermal-conductivity edge region is next to an edge of the negative electrode plate;

(2) a distance between an inner side of the low-thermal-conductivity edge region and the edge of the negative electrode plate is w, the negative electrode plate has a width of W, and a ratio W/w of W to w is equal to 11.5-21.9:1;

optionally, w=8-15 mm; and

optionally, W=100-200 mm;

(3) an outer side of one or more sides of the main body region is provided with a low-thermal-conductivity edge region;

(4) an area of the main body region accounts for 78.1%-88.5% of a unilateral area of the negative electrode plate;

(5) an area of the low-thermal-conductivity edge region accounts for 11.5%-21.9% of the unilateral area of the negative electrode plate; and

(6) a ratio of the area of the main body region to the area of the low-thermal-conductivity edge region is 3.6-7.7:1.

13 . A secondary battery, comprising an electrode assembly, wherein the electrode assembly comprises the negative electrode plate according to claim 1 .

14 . A battery module, comprising the secondary battery of claim 13 .

15 . A battery pack, comprising the battery module of claim 14 .

16 . A power consuming device, comprising the battery pack of claim 15 .

17 . A negative electrode plate, characterized in that,

the negative electrode plate comprises a main body region and at least one low-thermal-conductivity edge region;

the low-thermal-conductivity edge region and the main body region respectively have thermal conductivities of λ 2 and λ 1 , where λ 2 <λ 1 ; and

the negative electrode plate comprises a current collector layer and an active material layer, wherein

a priming coat belonging to the low-thermal-conductivity edge region is further provided between the current collector layer belonging to the low-thermal-conductivity edge region and the active material layer belonging to the low-thermal-conductivity edge region; and

the active material layer belonging to the main body region is directly laminated on the current collector layer belonging to the main body region.

18 . The negative electrode plate according to claim 17 , characterized in that, the priming coat belonging to the low-thermal-conductivity edge region comprises the following components:

50 wt %-60 wt % of conductive carbon black;

5 wt %-15 wt % of thermal resistance material; and

30 wt %-40 wt % of binder.

19 . The negative electrode plate according to claim 17 , characterized by any one of the following:

(1) a ratio λ 1 /λ 2 of λ 1 to λ 2 being 1.1-1.5:1;

(2) λ 1 having a value of 300-400 W/(m·K);

(3) λ 2 having a value of 200-300 W/(m·K).

20 . The negative electrode plate according to claim 17 , wherein the low-thermal-conductivity edge region and the main body region respectively have electrical conductivities of σ 2 and σ 1 ; and

the negative electrode plate meets a kinetic coefficient Q>0, and the kinetic coefficient Q is calculated by using the following formula:

Q

=

λ

2

-

λ

1

λ

2

-

1.2

(

σ

2

-

σ

1

)

σ

2

.