Cathode material and battery

1. A composite material represented by Formula IV:

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 )  IV

wherein:

x is in the range of from 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 in the range of from 0 to about 0.3;

v is in the range of from 0 to about 0.5;

w is in the range of from 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 in the range of from 0 to about 0.5;

y is in the range of from 0 to about 1; and

z is in the range of from about 0.3 to about 1; and

wherein:

(i) 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; and

(ii) “w+v” is greater than zero.

2. The composition of claim 1 , wherein y is in the range of from about 0.5 to about 1; wherein after the composition is fabricated into a cathode for an electrochemical cell, and the cathode is charged to a voltage sufficient to remove Li + ions from the component of the composite material represented as (Li y Mn 2−z M z O 4−d ) to the extent that y is decreased to a range of in the range of from 0 to about 0.2, and then discharged at a rate of 10 mA/g of composite material to a voltage of about 3.5 V vs. a Li/Li + reference electrode, the composition participates in discharge of the electrochemical cell such that the contribution to the discharge capacity attributable to the component of the composite material represented as (Li 2−w A 1−v Q w+v O 3−e ) is less than about 90 mAh/g.

3. The composition of claim 1 , wherein x is in the range of from about 0.01 to about 0.06.

4. The composition of claim 1 , wherein the Li y Mn 2−z M z O 4−d component is cation disordered.

5. The composition of claim 1 , wherein Q is one or more of Cr, Co, Cu, Fe, Ga, or Ni.

6. The composition of claim 1 , wherein e is in the range of from 0 to about 0.15.

7. The composition of claim 1 , wherein w is in the range of from 0 to about 0.3.

8. The composition of claim 1 , wherein M is one or more of Cr, Co, Fe, Ga, or Ni.

9. The composition of claim 1 , wherein M is (M′ y′ M″ y″ ), wherein:

M′ is Ni,

M″ is Cr, Co, Fe, or Ga,

y′ is from about 0.35 to about 0.5, and

y′+y″ equals y.

10. The composition of claim 1 wherein d is in the range of from 0 to about 0.2.

11. The composition of claim 1 , wherein z is in the range of from about 0.35 to about 0.6.

12. The composite material of claim 1 , wherein Q is one or more of Ca, Cr, Cu, Fe, Ga, Nb, V, Zn, or Y.

13. A lithium ion battery comprising

(a) a housing;

(b) an anode and a cathode disposed in the housing and in ionically conductive contact with one another, wherein the cathode comprises the composite material of claim 1 ;

(c) a nonaqueous electrolyte composition 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.

14. The lithium ion battery of claim 13 wherein the nonaqueous electrolyte composition comprises at least one electrolyte salt and at least one fluorinated ether, fluorinated acyclic carboxylic acid ester, fluorinated acyclic carbonate, or fluorinated cyclic carbonate.

15. A composite material represented by Formula IV:

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 )  IV

wherein:

x is in the range of from about 0.005 to less than 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, with the caveat that A and Q are not the same;

e is in the range of from 0 to about 0.3;

v is in the range of from 0 to about 0.5;

w is in the range of from 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 in the range of from 0 to about 0.5;

y is in the range of from 0 to about 1; and

z is in the range of from about 0.3 to about 1; and

wherein:

(i) 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; and

(ii) after the composition is fabricated into a cathode for an electrochemical cell, and the cathode is charged to a voltage of about 4.7 to about 4.95 V vs. Li/Li + , the component of the composite material represented as (Li 2−w A 1−v Q w+v O 3−e ) undergoes delithiation and is thereafter represented as (Li 2−w−g A 1−v Q w+v O 3−e−g/2 ), where g is less than about 0.3; and

(iii) “w+v” is greater than zero.

16. The composite material of claim 15 wherein g is in the range of from 0 to less than about 0.2.

17. The composite material of claim 15 wherein g is in the range of from 0 to about less than 0.2.