1. A method of making an oxyfluoride composition comprising the steps of:
firing a solid state mixture comprising lithium, manganese, and M to obtain a first composition having the formula LiMn2\u2212y\u2212zLiyMzO4;
mixing the first composition with a fluorine source to form a second mixture;
and heating the second mixture at a temperature within the range of about 200\xb0 C. to about 700\xb0 C. for 2 hours to 8 hours to form a cation-substituted, fluorine-substituted LiMn2\u2212y\u2212zLiyMzO4\u2212\u03b7F\u03b7 spinel oxide structure, wherein M is a metal, y is within the range of about 0 to about 0.3, z is within the range of about 0 to about 1.0, and wherein \u03b7 is greater than 0 and less than about 0.5, and wherein the fluorine source is a solid or liquid selected from the group consisting of NH4HF2, ammonium fluoride, or hydrogen fluoride.
2. The method of claim 1, wherein M is selected from the group consisting of Mg, Al, V, Cr, Fe, Ti, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ga, Sn and combinations thereof.
3. The method of claim 1, wherein the fluorine source comprises NH4HF2.
4. The method of claim 1, wherein y is within the range of about 0 to about 0.3, z is within the range of about 0 to about 1.0, and \u03b7 is within the range of about 0.05 to about 0.25.
5. The method of claim 1, wherein the first composition is heated in the presence of the fluorine source to a temperature within the range of about 425\xb0 C. to about 500\xb0 C.
6. The method of claim 1, wherein the cation-substituted fluorine-substituted LiMn2\u2212y\u2212zLiyMzO4\u2212\u03b7F\u03b7 spinel oxide structure is selected from the group consisting of LiMn1.8Li0.2O3.88F0.12, LiMn1.8Li0.2O3.79F0.21, LiMn1.8Li0.1Ti0.1O3.9F0.1, LiMn1.8Li0.1Cu0.1O3.9F0.1, LiMn1.8Li0.1Ni0.1O3.9F0.1, and LiMn1.8Li0.1Ni0.1O3.8F0.2.
7. The method of claim 1, wherein the second composition, when incorporated in a lithium-ion battery, has a capacity greater than about 80 mAhg.
8. The method of claim 1, wherein M is Ni.
9. The method of claim 1, wherein M is Ti.
10. The method of claim 1, wherein M is Cu.
11. The method of claim 1, wherein \u03b7 is within the range of about 0.05 to about 0.27.
12. The method of claim 1, wherein \u03b7 is within the range of about 0.1 to about 0.25.
13. The method of claim 1, wherein y is within the range of about 0.05 to about 0.27.
14. The method of claim 1, wherein y is within the range of about 0.1 to about 0.25.
15. The method of claim 1, wherein y is within the range of about 0.1 to about 0.2.
16. The method of claim 1, wherein y is within the range of about 0.1 to about 0.15.
17. The method of claim 1, wherein z is within the range of about 0.1 to about 0.9.
18. The method of claim 1, wherein y is within the range of about 0.2 to about 0.8.
19. The method of claim 1, wherein y is within the range of about 0.3 to about 0.7.
20. The method of claim 1, wherein y is within the range of about 0.4 to about 0.6.
21. The method of claim 1, wherein the first composition is heated in the presence of the fluorine source at a temperature within the range of about 200\xb0 C. to about 649\xb0 C.
22. The method of claim 1, wherein the first composition is heated in the presence of the fluorine source at a temperature within the range of about 300\xb0 C. to about 600\xb0 C.
23. The method of claim 1, wherein the first composition is heated in the presence of the fluorine source at a temperature within the range of about 350\xb0 C. to about 550\xb0 C.
24. The method of claim 1, wherein the first composition is heated in the presence of the fluorine source at a temperature within the range of about 400\xb0 C. to about 500\xb0 C.
25. The method of claim 1, wherein the first composition is heated in the presence of the fluorine source at a temperature within the range of about 425\xb0 C. to about 475\xb0 C.
26. The method of claim 1, wherein the first composition is heated in the presence of the fluorine source for about 2 hours to about 6 hours.
27. The method of claim 1, wherein the first composition is heated in the presence of the fluorine source for about 2 hours to about 5 hours.
28. The method of claim 1, wherein the first composition is heated in the presence of the fluorine source for about 2 hours to about 4 hours.
29. The method of claim 1, wherein the fluorine source comprises NH4F.
30. The method of claim 1, wherein the second composition is LiMn1.8Li0.2O3.88F0.12.
31. The method of claim 30, wherein the fluorine source comprises NH4HF2.
32. The method of claim 31, wherein the first composition is heated in the presence of a fluorine source at a temperature within the range of about 400\xb0 C. to about 500\xb0 C.
33. The method of claim 1, wherein the second composition is LiMn1.8Li0.2O3.79F0.21.
34. The method of claim 33, wherein the fluorine source comprises NH4HF2.
35. The method of claim 34, wherein the first composition is heated in the presence of a fluorine source at a temperature within the range of about 400\xb0 C. to about 500\xb0 C.
36. The method of claim 1, wherein the second composition is LiMn1.8Li0.1Ti0.1O3.9F0.1.
37. The method of claim 36, wherein the fluorine source comprises NH4HF2.
38. The method of claim 37, wherein the first composition is heated in the presence of a fluorine source at a temperature within the range of about 400\xb0 C. to about 500\xb0 C.
39. The method of claim 1, wherein the second composition is LiMn1.8Li0.1Cu0.1O3.9F0.1.
40. The method of claim 39, wherein the fluorine source comprises NH4HF2.
41. The method of claim 40, wherein the first composition is heated in the presence of a fluorine source at a temperature within the range of about 400\xb0 C. to about 500\xb0 C.
42. The method of claim 1, wherein the second composition is LiMn1.8Li0.1Ni0.1O3.9F0.1.
43. The method of claim 42, wherein the fluorine source comprises NH4HF2.
44. The method of claim 43, wherein the first composition is heated in the presence of a fluorine source at a temperature within the range of about 400\xb0 C. to about 500\xb0 C.
45. The method of claim 1, wherein the second composition is LiMn1.8Li0.1Ni0.1O3.8F0.2.
46. The method of claim 45, wherein the fluorine source comprises NH4HF2.
47. The method of claim 46, wherein the first composition is heated in the presence of a fluorine source at a temperature within the range of about 400\xb0 C. to about 500\xb0 C.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. An endoscope objective lens comprising at least one movable lens group, said movable lens group being movable so as to generate a curvature of field such that an image quality of a marginal part of a picture becomes favorable according to a form of an object while keeping a substantially constant magnification.
2. An endoscope objective lens according to claim 1, wherein said endoscope objective lens is an optical system having a variable focus.
3. An endoscope objective lens according to claim 1, wherein said endoscope objective lens is an optical system having a fixed focus.
4. An endoscope objective lens according to claim 1, wherein said endoscope objective lens comprises, successively from the object side, a first lens group having a negative refracting power, a second lens group having a positive refracting power, and a third lens group having a positive refracting power;
said second and third lens group being movable along an optical axis so as to generate said curvature of field.
5. An endoscope objective lens according to claim 4, further comprising a stop disposed near a lens constituting said second lens group on the object side.
6. An endoscope objective lens according to claim 1, wherein said endoscope objective lens comprises, successively from the object side, a first lens group having a negative refracting power, a second lens group having a positive refracting power, a third lens group having a negative refracting power, and a fourth lens group having a positive refracting power;
said second and third lens group being movable along an optical axis so as to generate said curvature of field.
7. An endoscope objective lens according to claim 6, further comprising a stop disposed between lenses in said third lens group.