Battery module and manufacturing method and device thereof, battery pack, and power consumption apparatus

1. A battery module, comprising:

at least one first-type battery cell and at least one second-type battery cell, and the first-type battery cell and the second-type battery cell being electrically connected at least in series,

a positive active substance in a positive electrode plate of the first-type battery cell being different from a positive active substance in a positive electrode plate of the second-type battery cell,

wherein under the conditions of 25° C. and 100% state of charge (SOC), specific power density P 2 of the second-type battery cell is higher than specific power density P 1 of the first-type battery cell,

a positive electrode plate of the first-type battery cell is a first positive electrode plate, and a positive electrode plate of the second-type battery cell is a second positive electrode plate, and satisfy:

0.04≤( r 1 /m )/( r 2 /n )≤14,

wherein, r 1 is a resistance per unit area of the first positive electrode plate, in Ω/cm 2 ;

r 2 is a resistance per unit area of the second positive electrode plate, in Ω/cm 2 ;

m is a number of laminations of the positive electrode plate of the first-type battery cell,

n is a number of laminations of the positive electrode plate of the second-type battery cell,

and both m and n are positive integers.

2. The battery module according to claim 1 , wherein the first-type battery cell and the second-type battery cell satisfy: 0.1≤(r 1 /m)/(r 2 /n)≤11.

3. The battery module according to claim 1 , wherein the resistance per unit area of the first positive electrode plate r 1 satisfies: 0.06 Ω/cm 2 ≤r 1 ≤9 Ω/cm 2 ; and/or,

the resistance per unit area of the second positive electrode plate r 2 satisfies: 0.1 Ω/cm 2 ≤r 2 ≤10 Ω/cm 2 .

4. The battery module according to claim 1 , wherein a conductivity of an electrolyte solution in the first-type battery cell is σ 1 , a conductivity of an electrolyte solution in the second-type battery cell is σ 2 , and satisfy: σ 2 <σ 1 ≤2σ 2 .

5. The battery module according to claim 1 , wherein an air permeability of a separator in the first-type battery cell is G 1 , an air permeability of a separator in the second-type battery cell is G 2 , and satisfy: G 1 <G 2 ≤1.5G 1 .

6. The battery module according to claim 1 , wherein the first-type battery cell and the second-type battery cell further satisfy at least one of the following conditions:

(1) 0.6≤P 1 /P 2 ≤0.98; and

(2) 0.9≤P 1 ′/P 2 ′≤2, wherein, P 1 ′ and P 2 ′ are specific power densities (in W/Ah) of the first-type battery cell and the second-type battery cell under 25° C. and 10% SOC.

7. The battery module according to claim 1 , wherein the battery module comprises M first-type battery cells and N second-type battery cells, the M and N are positive integers, nominal capacity of the first-type battery cell is Q 1 (in Ah), nominal capacity of the second-type battery cell is Q 2 (in Ah), and satisfy at least one of the following conditions:

(1) 0.15≤(M×Q 1 )/(N×Q 2 )≤10; and

(2) Q 1 ≤Q 2 .

8. The battery module according to claim 1 , wherein the first positive electrode plate contains a first positive active substance, and the first positive active substance comprises at least one of a lithium-containing phosphate represented by formula (I) or a lithium manganese-based oxide represented by formula (II),

LiFe 1−x2−y2 Mn x2 M′ y2 PO 4   formula (I),

Li 1+x3 Mn e N 2−e O 4−d B d   formula (II),

wherein in formula (I), 0≤x2≤1, 0≤y2≤0.1, and M′ is selected from one or more of transition metal elements other than Fe and Mn and non-transition metal elements; and in formula (II), −0.1≤x3≤0.2, 0<e≤2, and 0≤d<1, N is one or more of Ni, Fe, Cr, Ti, Zn, V, Al, Mg, Zr and Ce, and B is one or more of S, N, F, Cl, Br and I.

9. The battery module according to claim 1 , wherein the second positive electrode plate contains a second positive active substance, and the second positive active substance comprises a lithium transition metal oxide represented by formula (III),

Li 1+x1 Ni a Co b M 1−a−b O 2−y1 A y1   formula (III)

wherein −0.1≤x1≤0.2, 0.3≤a<0.95, 0<b<0.2, 0<a+b<1, 0≤y1<0.2, M is selected from one or more of Mn, Fe, Cr, Ti, Zn, V, Al, Zr and Ce, and A is selected from one or more of S, F, Cl and I.

10. The battery module according to claim 1 , wherein in the battery module, the first-type battery cell and the second-type battery cell are arranged in a horizontal direction, battery cells on the outermost side of the battery module are the second-type battery cell, and an inner side of the battery module contains the first-type battery cell.

11. The battery module according to claim 1 , wherein in the battery module, at least a portion of the first-type battery cells and the second-type battery cells are laminated in a vertical direction, and at least one of the first-type battery cell is located above the second-type battery cell.

12. The battery module according to claim 1 , wherein the electrical connection of the first-type battery cell and the second-type battery cell further comprises parallel connection.

13. A battery pack, comprising the battery module according to claim 1 .

14. A power consumption apparatus, comprising the battery module according to claim 1 , wherein the battery module or the battery pack is configured to provide power source to the power consumption apparatus and/or as an energy storage unit for the power consumption apparatus.

15. A manufacturing method for a battery module, comprising following steps:

obtaining at least one first-type battery cell and at least one second-type battery cell, a positive active substance in a positive electrode plate of the first-type battery cell is different from a positive active substance in a positive electrode plate of the second-type battery cell, wherein under the conditions of 25° C. and 100% state of charge (SOC), specific power density P 2 of the second-type battery cell is higher than specific power density P 1 of the first-type battery cell, a positive electrode plate of the first-type battery cell is a first positive electrode plate, and a positive electrode plate of the second-type battery cell is a second positive electrode plate, and satisfy:

0.04≤( r 1 /m )/( r 2 /n )≤14,

wherein, r 1 is a resistance per unit area of the first positive electrode plate, in Ω/cm 2 ;

r 2 is a resistance per unit area of the second positive electrode plate, in Ω/cm 2 ;

m is a number of laminations of the positive electrode plate of the first-type battery cell,

n is a number of laminations of the positive electrode plate of the second-type battery cell,

and both m and n are positive integers;

electrically connecting the first-type battery cell and the second-type battery cell at least in series to form the battery module according to claim 1 .

16. A manufacturing device for a battery module, wherein the manufacturing device comprises:

a clamping arm unit, configured to obtain at least one first-type battery cell and at least one second-type battery cell, a positive active substance in a positive electrode plate of the first-type battery cell is different from a positive active substance in a positive electrode plate of the second-type battery cell, wherein under the conditions of 25° C. and 100% state of charge (SOC), specific power density P 2 of the second-type battery cell is higher than specific power density P 1 of the first-type battery cell, a positive electrode plate of the first-type battery cell is a first positive electrode plate, and a positive electrode plate of the second-type battery cell is a second positive electrode plate, and satisfy:

0.04≤( r 1 /m )/( r 2 /n )≤14,

wherein, r 1 is a resistance per unit area of the first positive electrode plate, in Ω/cm 2 ;

r 2 is a resistance per unit area of the second positive electrode plate, in Ω/cm2;

m is a number of laminations of the positive electrode plate of the first-type battery cell,

n is a number of laminations of the positive electrode plate of the second-type battery cell,

and both m and n are positive integers;

an assembling unit, configured to electrically connect the first-type battery cell and the second-type battery cell at least in series to form the battery module according to claim 1 ; and a control unit, configured to control the clamping arm unit and the assembling unit.