Fast charge long-lifetime secondary battery, battery module, battery pack, and power consumption device

1. A secondary battery, comprising an electrode assembly and an electrolytic solution, the electrode assembly comprising a positive electrode plate, a negative electrode plate, and a separator, the positive electrode plate comprising a positive electrode tab, and the negative electrode plate comprising a negative electrode tab, wherein the positive electrode tab has a following temperature rise coefficient α A.h/mm:

α

=

C

1

⁢

0

⁢

S

⁢

1

where S1 is a total cross-sectional area of the positive electrode tab, in unit of mm 2 ; C is capacity of the electrode assembly, in unit of Ah, wherein α is from 2 to 9.5;

the electrolytic solution contains a heat stable salt and an additive that inhibits decomposition of lithium salt, wherein

the heat stable salt has a following molecular formula:

(M y+ ) x/y R 1 (SO 2 N) x SO 2 R 2 ,

wherein

M y+ is one or more selected from the group consisting of Li + , Na + , K + , Rb + , Cs + , Mg 2+ , Ca 2+ , Ba 2+ , Al 3+ , Fe 2+ , Fe 3+ , Ni 2+ , and Ni 3+ , optionally, M y+ is one or more selected from the group consisting of Li + , K + , Cs + , and Ba 2+ , and y is valence of the M,

the R 1 and R 2 are each independently selected from the group consisting of fluorine atom, fluoroalkyl having 1˜20 carbon atoms, fluoroalkoxy having 1˜20 carbon atoms, and alkyl having 1˜20 carbon atoms,

x is an integer selected from the group consisting of 1, 2, and 3,

by mass percentage, a content of the heat stable salt in the electrolytic solution is w %, wherein w % is from 8% to 30%,

the additive that inhibits decomposition of lithium salt is one or more of RSO 3 F, where R is one or more selected from the group consisting of Li + , Na + , K + , Rb + , and Cs + ,

by mass percentage, a content of the additive that inhibits decomposition of lithium salt in the electrolytic solution is m 1 %, wherein m 1 % is from 0.1% to 5%, and

w, m 1 , and α satisfy 0.5<m 1 w/α<20.

2. The secondary battery according to claim 1 , wherein the heat stable salt has a temperature corresponding to 5% weight loss rate higher than 200° C.

3. The secondary battery according to claim 1 , wherein in the molecular formula of the heat stable salt, x=1 and y=1, or x=1 and y=2, or x=2 and y=1.

4. The secondary battery according to claim 1 , wherein in the molecular formula of the heat stable salt, R 1 and R 2 are each independently selected from fluorine atom and trifluoromethyl; and optionally, R 1 and R 2 are both fluorine atom or both trifluoromethyl.

5. The secondary battery according to claim 1 , wherein the heat stable salt is one or more selected from the group consisting of: lithium bisfluorosulfonyl imide, potassium bisfluorosulfonyl imide, cesium bisfluorosulfonyl imide, barium bisfluorosulfonyl imide, lithium bistrifluoromethanesulfonyl imide, Li 2 F(SO 2 N) 2 SO 2 F, and LiCF 3 SO 2 NSO 2 F.

6. The secondary battery according to claim 1 , wherein the additive that inhibits decomposition of lithium salt is one or more of LiSO 3 F, NaSO 3 F, or KSO 3 F.

7. The secondary battery according to claim 1 , wherein the electrolytic solution further contains a fluorinated solvent, and the fluorinated solvent is one or more selected from the group consisting of fluorinated carbonate, fluorobenzene, and fluoroether.

8. The secondary battery according to claim 7 , wherein a content of the fluorinated solvent in the electrolytic solution is m 2 %, m 2 % is from 3% to 60%, and a ratio m 2 /α of m 2 to α is 1˜8.

9. The secondary battery according to claim 7 , wherein

the fluorinated carbonate is

and/or, the fluorobenzene is

and/or, the fluoroether is R 1′ —O—R 2′ ,

where R 3 , R 4 , R 5 , R 6 , R 1′ , and R 2′ are each independently —C x′ F y′ H z′ , 1≤x′≤6, y′>0, z′>0, and 0≤y′≤2x′, 0≤z′≤2x′, and

R 7 , R 8 , R 9 , R 10 , R 11 , and R 12 are each independently one of F or H.

10. The secondary battery according to claim 9 , wherein R 1′ and R 2′ are each independently selected from a group consisting of —C 2 F 4 H, —CF 3 , —C 3 F 6 H, —C 2 F 3 H 2 , and —C 3 F 4 H 3 ;

optionally, R 1′ and R 2′ are each independently selected from the group consisting of —CF 2 —CF 2 H, —CF 3 , —CF 2 —CFH—CF 3 , —CH 2 —CF 3 , and —CH 2 —CF 2 —CHF 2 ; and

optionally, the fluoroether is selected from following structures:

11. The secondary battery according to claim 9 , wherein R 5 and R 6 are each independently selected from a group consisting of —C 2 F 3 H, —CFH, and —CH 2 ;

optionally, R 5 and R 6 are each independently selected from the group consisting of —CH—CF 3 , —CHF, and —CH 2 ; and

optionally, the fluorinated carbonate is selected from the group consisting of:

12. The secondary battery according to claim 9 , wherein R 5 and R 6 are each independently selected from a group consisting of —CH 3 , —C 2 F 3 H 2 , —CFH 2 , and —C 2 FH 4 ;

optionally, R 5 and R 6 are each independently selected from the group consisting of —CH 3 , —CH 2 —CF 3 , —CH 2 —F, and —CH 2 —CH 2 —F; and

optionally, the fluorinated carbonate is selected from the group consisting of:

13. The secondary battery according to claim 1 , wherein the electrolytic solution further contains an additive prone to lose electrons, and the additive prone to lose electrons is one or more selected from the group consisting of phosphite, borate, and phosphate.

14. The secondary battery according to claim 13 , wherein a content of the additive prone to lose electrons in the electrolytic solution is m 3 %, m 3 % is from 0.5% to 1.2%, and a ratio m 3 /α of m 3 to α is 0.1˜0.9.

15. The secondary battery according to claim 13 , wherein the phosphite is

and/or, the phosphate is

and/or, the borate is

where R 13 , R 14 , R 15 , R 16 , R 17 , R 18 , R 19 , R 20 , and R 21 are each independently selected from the group consisting of: alkyl, fluoroalkyl, silyl, alkenyl, and phenyl.

16. The secondary battery according to claim 15 , wherein R 13 , R 14 , and R 15 are each independently selected from the group consisting of C 1-6 alkyl (e.g., methyl, ethyl) and C 1-6 fluoroalkyl (e.g., fluoromethyl, fluoroethyl, e.g., —CH 2 —CF 3 ); and

optionally, the phosphite is selected from

17. The secondary battery according to claim 15 , wherein R 16 , R 17 , and R 18 are each independently selected from C 1-6 fluoroalkyl (e.g., fluoromethyl, fluoroethyl, e.g., —CH 2 —CF 3 ) and C 1-6 alkenyl (e.g., allyl); and

optionally, the phosphate is selected from:

18. The secondary battery according to claim 15 , wherein R 19 , R 20 , and R 21 are each independently selected from the group consisting of C 1-6 alkyl (e.g., methyl, ethyl) and C 1-6 fluoroalkyl (e.g., fluoromethyl, fluoroethyl, e.g., —CH 2 —CF 3 ); and

optionally, the borate is selected from

19. A battery module, comprising the secondary battery according to claim 1 .