Nonaqueous electrolyte compositions comprising lithium oxalato phosphates

1. An electrolyte composition comprising:

a) a fluorinated solvent, which is a fluorinated acyclic carboxylic acid ester CH3—COO—CH 2 CF 2 H, wherein said fluorinated solvent comprises 30% to 75% by weight of the electrolyte composition;

b) from about 0.01 wt % to 25 wt % based on the total weight of the electrolyte composition of an oxalate salt represented by the Formula:

LIPF (6-2q) (O x ) q

wherein Ox is an oxalate moiety, and q is 1, 2 or 3, wherein the oxalate salt comprises lithium tris(oxalato)phosphate; and

c) optionally, at least one electrolyte salt.

2. The electrolyte composition of claim 1 , wherein the electrolyte composition comprises a mole ratio of Ox/P in the range of from about 0.001 to about 5.

3. The electrolyte composition of claim 2 , wherein the mole ratio of Ox/P is in the range of from about 0.1 to about 0.5.

4. The electrolyte composition of claim 2 , wherein the electrolyte composition further comprises lithium bis(oxalato)borate, and the mole ratio of Ox/B of the electrolyte composition is above 2.

5. The electrolyte composition of claim 1 , wherein the electrolyte salt is present, and the electrolyte salt comprises LiPF 6 .

6. The electrolyte composition of claim 1 , further comprising at least one cyclic carbonate.

7. The electrolyte composition of claim 6 , wherein the cyclic carbonate comprises fluoroethylene carbonate and/or ethylene carbonate.

8. The electrolyte composition of claim 1 , wherein the composition further comprises:

i) a cyclic sultone represented by the formula:

wherein each A is independently a hydrogen, fluorine, or an optionally fluorinated alkyl, vinyl, allyl, acetylenic, or propargyl group;

ii) a cyclic sulfate represented by the formula:

wherein each B is independently a hydrogen or an optionally fluorinated vinyl, allyl, acetylenic, propargyl, or C 1 -C 3 alkyl group;

iii) a cyclic carboxylic acid anhydride selected from the group consisting of the compounds represented by Formula (I) through Formula (VIII):

wherein R 7 to R 14 is each independently H, F, a linear or branched C 1 to C 10 alkyl radical optionally substituted with F, alkoxy, and/or thioalkyl substituents, a linear or branched C 2 to C 10 alkene radical, or a C 6 to C 10 aryl radical;

or a combination thereof.

9. The electrolyte composition of claim 8 , wherein the cyclic sultone comprises 1,3-propane sultone.

10. 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.

11. The electrochemical cell of claim 10 , wherein the electrochemical cell is a lithium ion battery.

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

13. The electrochemical cell of claim 11 , wherein the cathode comprises:

a) a lithium-containing manganese composite oxide having a spinel structure as active material, the lithium-containing manganese composite oxide being represented by 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 structure of 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 0.005 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; and

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) Li a Mn b J c O 4 Z d

wherein:

J is Ni, Co, Mn, Cr, Fe, Cu, V, Ti, Zr, Mo, B, Al, Ga, Si, Li, Mg, Ca, Sr, Zn, Sn, a rare earth element, or a combination thereof; Z is F, S, P, or a combination thereof; and 0.9≤a≤1.2, 1.3≤b≤2.2, 0≤c≤0.7, 0≤d≤0.4; or

d) Li a Ni b Mn c Co d R e O 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;

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

e) 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; or

f) 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.

14. An electronic device, transportation device, or telecommunications device, comprising an electrochemical cell according to claim 10 .

15. A method comprising:

combining:

a) a fluorinated solvent, which is a fluorinated acyclic carboxylic acid ester CH 3 —COO—CH 2 CF 2 H, wherein said fluorinated solvent comprises 30% to 75% by weight of the electrolyte composition;

b) from about 0.01 wt % to 25 wt % based on the total weight of the electrolyte composition of an oxalate salt represented by the Formula:

LIPF (6-2q) (O x ) q

wherein Ox is an oxalate moiety, and q is 1, 2 or 3, wherein the oxalate salt comprises lithium tris(oxalato)phosphate;

c) and optionally, at least one electrolyte salt;

to form an electrolyte composition.