Nonaqueous electrolyte compositions comprising lithium malonatoborate and fluorinated solvent

Patent metadata

Field	Value
Publication number	US-10535898-B2
Application number	US-201514968933-A
Country	US
Kind code	B2
Filing date	Dec 15, 2015
Priority date	Dec 17, 2014
Publication date	Jan 14, 2020
Grant date	Jan 14, 2020

Abstract

Disclosed herein are electrolyte compositions comprising: a non-fluorinated carbonate; a fluorinated solvent; a lithium bis(malonato) borate compound represented by the formula:

wherein each Q 1 and Q 2 is independently a hydrogen, alkyl, allyl, acetylenic, aryl, or propargyl group; a fluorinated carbonate; and an electrolyte salt. The electrolyte compositions are useful in electrochemical cells, such as lithium ion batteries.

First claim

What is claimed is:

1. An electrolyte composition comprising:
a) a non-fluorinated carbonate selected from ethylene carbonate, propylene carbonate, and mixtures thereof;
b) a fluorinated solvent comprising at least 2,2-difluoroethylacetate;
c) a lithium bis(malonato) borate compound selected from bis(2,2-dimethylmalonato) borate, bis(malonato) borate, bis(ethylmethylmalonato) borate, or bis(allylmalonato) borate;
d) a fluorinated carbonate different from the fluorinated solvent and which comprises fluoroethylene carbonate; and
e) an electrolyte salt.

2. The electrolyte composition of claim 1 , wherein the non-fluorinated carbonate comprises ethylene carbonate.

3. The electrolyte composition of claim 1 , wherein the fluorinated solvent further comprises:
a) a fluorinated acyclic carbonate represented by the formula:
R 3 —OCOO—R 4 ,

b) a fluorinated acyclic ether represented by the formula:
R 5 —O—R 6 ,

or a mixture thereof;
wherein
i) R 3 and R 5 is each independently a fluoroalkyl group and can be either the same as or different from each other;
ii) R 4 , and R 6 is each independently an alkyl group or a fluoroalkyl group and can be either the same as or different from each other; and
iii) R 3 and R 4 , and R 5 and R 6 , each taken as a pair, comprise at least two carbon atoms but not more than seven carbon atoms.

4. The electrolyte composition of claim 3 , wherein R 3 and R 4 , and R 5 and R 6 , each taken as a pair, further comprise at least two fluorine atoms, with the proviso that none of R 3 , R 4 , R 5 , nor R 6 contains a —CH 2 F or —CHF— group.

5. The electrolyte composition of claim 1 , wherein the fluorinated solvent further comprises CH 3 CH 2 —COOCH 2 CF 2 H, F 2 CHCH 2 —COO—CH 3 , F 2 CHCH 2 —COO—CH 2 CH 3 , CH 3 —COO—CH 2 CH 2 CF 2 H, CH 3 CH 2 —COO—CH 2 CH 2 CF 2 H, F 2 CHCH 2 CH 2 —COO—CH 2 CH 3 , CH 3 —COOCH 2 CF 3 , CH 3 CH 2 —COO—CH 2 CF 2 H, or mixtures thereof.

6. The electrolyte composition of claim 1 , wherein the electrolyte composition comprises about 0.5 weight percent to about 5 weight percent of a cyclic fluorinated carbonate and 0.01 weight percent to 5 weight percent of a lithium bis(malonato) borate, based on the weight of the electrolyte composition.

7. An electrochemical cell comprising:
(a) a housing;
(b) an anode and a cathode disposed in the housing and in ionically conductive contact with one another;
(c) the electrolyte composition of claim 1 disposed in the housing and providing an ionically conductive pathway between the anode and the cathode; and
(d) a porous separator between the anode and the cathode.

8. The electrochemical cell of claim 7 , wherein the electrochemical cell is a lithium ion battery.

9. The electrochemical cell of claim 8 , wherein the anode comprises an anode active material and the anode active material is lithium titanate or graphite.

10. The electrochemical cell of claim 8 , wherein the cathode comprises a cathode active material exhibiting greater than 30 mAh/g capacity in the potential range greater than 4.6 V versus a Li/Li+ reference electrode.

11. The electrochemical cell of claim 8 , wherein the cathode comprises a cathode active material which is charged to a potential greater than or equal to 4.35 V versus a Li/Li+ reference electrode.

12. The electrochemical cell of claim 8 , wherein the cathode active material comprises:
a) a lithium-containing manganese composite oxide having a spinel structure as active material, the lithium-containing manganese composite oxide comprising oxides of the formula
Li x Ni y M z Mn 2−y−z O 4−d

wherein x is 0.03 to 1.0; x changes in accordance with release and uptake of lithium ions and electrons during charge and discharge;
y is 0.3 to 0.6; M comprises one or more of Cr, Fe, Co, Li, Al, Ga, Nb, Mo, Ti, Zr, Mg, Zn, V, and Cu;
z is 0.01 to 0.18, and
d is 0 to 0.3; or
b) a composite material represented by the formula:
x(Li 2−w A 1−v Q w+v O 3−e )·(1−x)Li y Mn 2−z M z O 4−d )

wherein:
x is about 0 to about 0.1;
A comprises one or more of Mn or Ti;
Q comprises one or more of Al, Ca, Co, Cr, Cu, Fe, Ga, Mg, Nb, Ni, Ti, V, Zn, Zr or Y;
e is 0 to about 0.3;
v is 0 to about 0.5;
w is 0 to about 0.6;
M comprises one or more of Al, Ca, Co, Cr, Cu, Fe, Ga, Li, Mg, Mn, Nb, Ni, Si, Ti, V, Zn, Zr or Y;
d is 0 to about 0.5;
y is about 0 to about 1;
z is about 0.3 to about 1; and
wherein the Li y Mn 2−z M z O 4−d component has a spinel structure and the Li 2−w Q w+v A 1−v O 3−e component has a layered structure; or
c) a composition of the formula Li a Ni b Mn c Co d ReO 2−f Z f ,

wherein:
R is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, Zr, Ti, a rare earth element, or a combination thereof, and Z is F, S, P, or a combination thereof; and 0.8≤a≤1.2, 0.1≤b≤0.9, 0.0≤c≤0.7, 0.05≤d≤0.4, 0≤e≤0.2; wherein the sum of b+c+d+e is about 1; and 0≤f≤0.08; or
d) a composition of the formula Li a A 1−x R x DO 4−f Z f ,
wherein:
A is Fe, Mn, Ni, Co, V, or a combination thereof; R is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, Zr, Ti, a rare earth element, or a combination thereof; D is P, S, Si, or a combination thereof; Z is F, Cl, S, or a combination thereof;
0.8≤a≤2.2;
0≤x≤0.3; and
0≤f≤0.1; or

e) a composition of the formula Li a A 1−b ,R b D 2 ,
wherein:
A is Ni, Co, Mn, or a combination thereof;
R is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, Zr, Ti, a rare earth element, or a combination thereof;
D is O, F, S, P, or a combination thereof; and 0.90≤a≤1.8 and 0≤b≤0.5.

13. An electronic device, transportation device, or telecommunications device, comprising the electrochemical cell of claim 7 .

14. A method comprising combining:
a) a non-fluorinated carbonate selected from ethylene carbonate, propylene carbonate, and mixtures thereof;
b) a fluorinated solvent comprising at least 2,2-difluoroethylacetate;
c) a lithium bis(malonato) borate compound selected from bis(2,2-dimethylmalonato) borate, bis(malonato) borate, bis(ethylmethylmalonato) borate, or bis(allylmalonato) borate;
d) a fluorinated carbonate different from the fluorinated solvent and which comprises fluoroethylene carbonate; and
e) an electrolyte salt;
to form an electrolyte composition.

Assignees

• Solvay

Inventors

• Dubois Charles J

Classifications

• H01M4/587

  for inserting or intercalating light metals · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title

• H01M2300/0037

  Mixture of solvents · CPC title

• H01M2300/0034

  Fluorinated solvents · CPC title