Electrolyte, electrochemical device including same, and electronic device

1 . An electrolyte, comprising: a dinitrile compound, a multi-nitrile compound with more than two cyano groups, a boron-containing lithium salt, and a boron-free lithium salt;

wherein the boron-containing lithium salt comprises at least one of lithium bis(oxalato)borate, lithium difluoro(oxalato)borate, or lithium tetraborate;

wherein, based on a total weight of the electrolyte, a content of the dinitrile compound is A %, a content of the multi-nitrile compound is B %, and a content of the boron-containing lithium salt is C %,

0≤( A/B )− C+ 1≤11,2.3≤ A/B≤ 9, and 5≤ A+B≤ 20; and

based on the total weight of the electrolyte, a content of the boron-free lithium salt is D %, and 0.01≤C/D×12.5≤3.8.

2 . The electrolyte according to claim 1 , wherein the dinitrile compound comprises a compound represented by Formula I:

wherein, R 1 is selected from a substituted or unsubstituted C 1 to C 9 alkylidene, a substituted or unsubstituted C 2 to C 10 alkenylene, —R a —O—R b —, or —R c —O—R d —O—R e —, wherein R a , R b , R c , and R e each are independently selected from a single bond or a substituted or unsubstituted C 1 to C 5 alkylidene, R a and R b are not both single bonds, and R d is selected from a substituted or unsubstituted C 1 to C 5 alkylidene, in which a substituent for substitution is halogen;

the multi-nitrile compound comprises a compound represented by Formula II:

wherein, R 2 is selected from H, C, CH, CH 2 , or CH 3 ;

R 3 is selected from C, CH, or CH 2 ;

R 4 , R 5 , R 6 , R 7 R 8 , R 9 , and R 10 each are independently selected from a single bond, a substituted or unsubstituted C 1 to C 5 alkylidene, or —R f —O—R g —, wherein R f and R g each are independently selected from a single bond or a substituted or unsubstituted C 1 to C 5 alkylidene, in which a substituent for substitution is halogen;

X 1 and X 2 each are independently selected from a single bond, oxygen, or a substituted or unsubstituted C 1 to C 5 alkylidene, in which a substituent for substitution is halogen; and

a, b, c, d, e, f, and g each are independently 0 or 1, and at least three of a, b, c, d, e and f are not zero.

3 . The electrolyte according to claim 1 , wherein the dinitrile compound comprises at least one of:

and

the multi-nitrile compound comprises at least one of:

4 . The electrolyte according to claim 1 , wherein the boron-containing lithium salt further comprises lithium tetrafluoroborate, wherein C≤A.

5 . The electrolyte according to claim 1 , further comprising fluoroethylene carbonate and, based on the total weight of the electrolyte, a content of the fluoroethylene carbonate is E %, and 5≤A+E≤25.

6 . The electrolyte according to claim 1 , wherein 2.5≤A≤16.

7 . The electrolyte according to claim 1 , wherein 4.9≤(A/B)−C+1≤11.

8 . The electrolyte according to claim 1 , wherein 6≤A≤16.

9 . The electrolyte according to claim 1 , further comprising fluoroethylene carbonate and, based on the total weight of the electrolyte, a content of the fluoroethylene carbonate is E %, wherein 12≤A+E≤25.

10 . An electrochemical device, wherein the electrochemical device comprising a positive electrode, a negative electrode, a separator, and an electrolyte, wherein the electrolyte comprises a dinitrile compound, a multi-nitrile compound with more than two cyano groups, a boron-containing lithium salt, and a boron-free lithium salt,

wherein the boron-containing lithium salt comprises at least one of lithium bis(oxalato)borate, lithium difluoro(oxalato)borate, or lithium tetraborate;

wherein, based on a total weight of the electrolyte, a weight percent of the dinitrile compound is A %, a content of the multi-nitrile compound is B %, and a content of the boron-containing lithium salt is C %,

0≤( A/B )− C+ 1≤11,2.3≤ A/B≤ 9, and 5≤ A+B≤ 20; and

based on the total weight of the electrolyte, a content of the boron-free lithium salt is D %, and 0.01≤C/D×12.5≤3.8.

11 . The electrochemical device according to claim 10 , wherein the dinitrile compound comprises at least one of:

and

the multi-nitrile compound comprises at least one of:

12 . The electrochemical device according to claim 10 , wherein the boron-containing lithium salt further comprises lithium tetrafluoroborate.

13 . The electrochemical device according to claim 10 , wherein C≤A.

14 . The electrochemical device according to claim 10 , further comprising fluoroethylene carbonate and, based on the total weight of the electrolyte, a content of the fluoroethylene carbonate is E %, and 5≤A+E≤25.

15 . The electrochemical device according to claim 10 , wherein the negative electrode comprises negative active material particles, and the negative active material particles satisfy at least one of condition (a) or (b):

(a) D n10 of the negative active material particles is 1 μm to 9 μm; and

(b) D v50 of the negative active material particles is 5 μm to 18 μm.

16 . The electrochemical device according to claim 15 , wherein, when the negative active material particles satisfy at least condition (a), the negative active material particles further satisfy at least one of condition (c) or (d):

(c) when D n10 of the negative active material particles is less than 5 μm, 5D n10 <D v50<12 D n10 ; and

(d) when D n10 of the negative active material particles is greater than or equal to 5 μm, 1.5D n10 <D v50<4 D n10 .

17 . An electronic device, wherein the electronic device comprises a electrochemical device, wherein the electrochemical device comprises a positive electrode, a negative electrode, a separator, and an electrolyte, wherein the electrolyte comprises a dinitrile compound, a multi-nitrile compound with more than two cyano groups, a boron-containing lithium salt, and a boron-free lithium salt;

wherein the boron-containing lithium salt comprises at least one of lithium bis(oxalato)borate, lithium difluoro(oxalato)borate, or lithium tetraborate;

wherein, based on a total weight of the electrolyte, a content of the dinitrile compound is A %, a content of the multi-nitrile compound is B %, and a content of the boron-containing lithium salt is C %,

0≤( A/B )− C+ 1≤11,2.3≤ A/B≤ 9, and 5≤ A+B≤ 20; and

based on the total weight of the electrolyte, a content of the boron-free lithium salt is D %, and 0.01≤C/D×12.5≤3.8.