Claims
- 1. A secondary cell comprising
- a positive electrode including an active material and a conductive element,
- a negative electrode and
- an electrolyte in contact with the positive and negative electrodes,
- wherein the conductive element comprises flake graphite and a carbon black having a hollow shell structure with graphite crystals accumulated outside thereof, a DBP oil absorption of about 200 ml/100 g a surface area of about 500 m.sup.2 /g at nitrogen adsorption method, and porosity about 35% or more,
- wherein the content of the carbon black is within a range of about 0.2 parts by weight to about 1.0 part by weight with respect to 100 parts by weight of the active material, and
- a value of 3X+(3/8)Y is within a range of about 1.0 to about 3.5 where X is the content of the carbon black expressed by units of part by weight, and Y is the content of the flake graphite expressed by units of part by weight with respect to 100 parts by weight of the active material.
- 2. A secondary cell of claim 1,
- wherein the electrolyte is a non-aqueous electrolyte.
- 3. A secondary cell of claim 1, wherein powders of the carbon black and powders of the active material are distributed in relation to each other, and bound together by a binder.
- 4. A secondary cell of claim 1,
- wherein the positive electrode comprises a metallic plate and a positive electrode material provide in both sides of the metallic plate, and
- the positive electrode material includes the carbon black and the active material that are distributed in relation to each other.
- 5. A secondary cell of claim 1,
- wherein the positive and the negative electrodes are faced against each other with a separator between them, and wound in a spiral manner.
- 6. A secondary cell of claim 1,
- wherein the active material is at least one selected from the group consisting of LiCoO.sub.2, LiMn.sub.2 O.sub.4 and LiNi.sub.2 O.sub.4.
- 7. A secondary cell comprising:
- a positive electrode including an active material and a conductive element,
- a negative electrode and
- an electrolyte in contact with the positive and negative electrodes,
- wherein the conductive element includes acetylene black and a carbon black having a hollow shell structure with graphite crystals accumulated outside thereof, a DBP oil absorption of about 200 ml/100 g a surface area of about 500 m.sup.2 /g at nitrogen adsorption method, and porosity about 35% or more,
- wherein the content of the carbon black is within a range of about 0.2 parts by weight to about 1.0 part by weight with respect to 100 parts by weight of the active material, and
- a value of 3X+Z is within a range of about 1.1 to about 3.5 where X is the content of the carbon black expressed by units of part by weight, and Z is the content of the acetylene black expressed by units of part by weight with respect to 100 parts by weight of the active material.
- 8. A secondary cell of claim 7,
- wherein the electrolyte is a non-aqueous electrolyte.
- 9. A secondary cell of claim 7, wherein powders of the carbon black and powders of the active material are distributed in relation to each other, and bound together by a binder.
- 10. A secondary cell of claim 7,
- wherein the positive electrode comprises a metallic plate and a positive electrode material provided in both sides of the metallic plate, and
- the positive electrode material includes the carbon black and the active material that are distributed in relation to each other.
- 11. A secondary cell of claim 7,
- wherein the negative electrode is of a band-like shape, and
- the positive and negative electrodes are faced against each other with a separator between them, and wound in a spiral manner.
- 12. A secondary cell of claim 7,
- wherein the active material is at least one selected from the group consisting of LiCoO.sub.2, LiMn.sub.2 O.sub.4 and LiNi.sub.2 O.sub.4.
Priority Claims (1)
Number |
Date |
Country |
Kind |
9-055830 |
Mar 1997 |
JPX |
|
Parent Case Info
This Application is a U.S. National Phase Application of PCT International Application PCT/ JP98/00752.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
102e Date |
371c Date |
PCT/JP98/00752 |
2/25/1998 |
|
|
11/12/1998 |
11/12/1998 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO98/40919 |
9/17/1998 |
|
|
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5133842 |
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|
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Jun 1998 |
|
5789114 |
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Aug 1998 |
|
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Jan 1999 |
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Number |
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Country |
1-149370 |
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JPX |
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JPX |
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JPX |
8-78003 |
Mar 1996 |
JPX |
9-129216 |
May 1997 |
JPX |
Non-Patent Literature Citations (2)
Entry |
Japanese language search report for Int'l Appln No. PCT/JP98/00752 dated Jun. 16, 1998. |
Copy of Form PCT/ISA/210. |