Claims
- 1. A method for manufacturing graphite powder, comprising the steps of:
pulverizing raw graphite, to produce pulverized graphite; sieving said pulverized graphite for obtaining graphite powder having maximum particle diameter of 100 μm; immersing said graphite powder into an acidic solution as an immersion treatment; washing with water; neutralizing; and drying.
- 2. A method for manufacturing graphite powder as claimed in claim 1, wherein said acidic solution contains at least one compound selected from a group consisting of sulfuric acid, nitric acid, perchloric acid, phosphoric acid, and fluoric acid.
- 3. A non-aqueous secondary battery, comprising:
a positive electrode, a negative electrode, and electrolytic solution, which is charged or discharged by repeating a reaction of intercalating and deintercalating ions at said positive electrode and said negative electrode, respectively, wherein
said graphite powder composing said negative electrode has a particle size equal to or smaller than 100 μm, and said negative electrode comprises graphite powder having a fraction of a rhombohedral structure equal to or less than 20% by weight.
- 4. A non-aqueous secondary battery as claimed in claim 3, wherein
said graphite powder has a fraction of a hexagonal structure equal to or more than 80% by weight.
- 5. A non-aqueous secondary battery, comprising:
a positive electrode, a negative electrode, and electrolytic solution, which is charged or discharged by repeating a reaction of intercalating and deintercalating ions at said positive electrode and said negative electrode, respectively, wherein
said graphite powder composing said negative electrode has a particle size equal to or smaller than 100 μm, and said negative electrode comprises graphite powder having a fraction of a rhombohedral structure equal to or less than 10% by weight.
- 6. A non-aqueous secondary battery as claimed in claim 5, wherein said graphite powder has a fraction of a hexagonal structure equal to or more than 90% by weight.
- 7. A non-aqueous secondary battery, comprising:
a positive electrode, a negative electrode, and electrolytic solution, which is charged or discharged by repeating a reaction of intercalating and deintercalating ions at said positive electrode and said negative electrode, respectively, wherein
said negative electrode comprises graphite powder having a particle size equal to or smaller than 100 μm, said graphite powder has both a hexagonal structure and a rhombohedral structure, and said graphite powder has a fraction of the rhombohedral structure equal to or less than 20% by weight, and a fraction of the hexagonal structure equal to or more than 80% by weight.
- 8. A non-aqueous secondary battery, made by a method comprising the steps of:
laminating electrodes with graphite for a positive electrode and with a lithium group oxide for a negative electrode; and enclosing said electrodes laminated with graphite into a cell vessel with an electrolyte solution, wherein
said electrodes laminated with graphite are manufactured by the steps of:
pulverizing the graphite to graphite powder having a particle size equal to or smaller than 100 μm, treating said graphite powder by heating at 900° C. or higher, after said pulverizing, and fabricating said graphite electrodes by subjecting the heat-treated graphite powder to pressing.
- 9. A non-aqueous secondary battery according to claim 8, wherein said treating said graphite powder by heating is performed so as to modify crystallinity of the graphite powder such that a fraction of the graphite powder having rhombohedral structure is equal to or less than 20% by weight.
- 10. A non-aqueous secondary battery according to claim 9, wherein, in said treating said graphite powder by heating, said crystallinity of the graphite powder is modified so that a fraction of the graphite powder having hexagonal structure is equal to or greater than 80% by weight.
- 11. A non-aqueous secondary battery according to claim 9, wherein crystallinity of the graphite powder is modified during the heat treatment so that a fraction of the graphite powder having rhombohedral structure is equal to or less than 10% by weight.
- 12. A non-aqueous secondary battery, made by a method comprising the steps of:
laminating electrodes with graphite for a positive electrode and with a lithium group oxide for a negative electrode; and enclosing said electrodes laminated with graphite into a cell vessel with an electrolyte solution, wherein
said electrodes laminated with graphite are manufactured by the steps of:
pulverizing the graphite to graphite powder having a particle size equal to or smaller than 100 μm, immersing said graphite powder into an acidic solution as an immersing treatment, said acidic solution containing at least one compound selected from a group consisting of sulfuric acid, nitric acid, perchloric acid, phosphoric acid and fluoric acid, and then washing said graphite powder with water, neutralizing, and drying said graphite powder, and fabricating said electrodes laminated with graphite by subjecting the dried graphite powder to pressing.
- 13. A method of manufacturing a lithium secondary battery, comprising the steps of:
laminating electrodes with graphite for a positive electrode and with a lithium group oxide for a negative electrode; and enclosing said electrodes laminated with graphite into a cell vessel with an electrolyte solution, wherein
said electrodes laminated with graphite are manufactured by the steps of:
pulverizing the graphite to graphite powder having a particle size equal to or smaller than 100 μm, treating said graphite powder by heating at 900° C. or higher, after said pulverizing, and fabricating said electrodes laminated with graphite by subjecting the heat-treated graphite powder to pressing.
- 14. A method of manufacturing a lithium secondary battery, comprising the steps of:
laminating electrodes with graphite for a positive electrode and with a lithium group oxide for a negative electrode; and enclosing said electrodes laminated with graphite into a cell vessel with an electrolyte solution, wherein
said electrodes laminated with graphite are manufactured by the steps of:
pulverizing the graphite to graphite powder having a particle size equal to or smaller than 100 μm, immersing said graphite powder into an acidic solution as an immersing treatment, washing said graphite powder, neutralizing said graphite powder, and drying said graphite powder, and fabricating said electrodes laminated with graphite by subjecting the dried graphite powder to pressing.
- 15. A method of manufacturing a lithium secondary battery according to claim 14, wherein said acidic solution contains at least one compound selected from a group consisting of sulfuric acid, nitric acid, perchloric acid, phosphoric acid and fluoric acid.
- 16. A method of manufacturing a lithium secondary battery, comprising the steps of:
fabricating graphite electrodes by subjecting graphite powder to pressing; laminating said graphite electrodes with a lithium group oxide; and enclosing said graphite electrodes into a cell vessel with an electrolyte solution, wherein
said graphite powder is manufactured by a method comprising the steps of:
graphitizing raw graphite by heating raw graphite to at least 2000° C., to produce graphitized raw graphite; pulverizing said graphitized raw graphite, to produce pulverized graphite; sieving said pulverized graphite for obtaining graphite powder having a maximum particle diameter of 100 μm; and either (a) heating said graphite powder as a heat treatment for transforming the crystalline structure to hexagonal structure, and further heating said graphite powder, at a higher temperature than said heat treatment for transforming the crystalline structure, for eliminating impurities; or (b) immersing said graphite powder into an acidic solution as an immersing treatment, washing with water, neutralizing and drying.
- 17. A non-aqueous secondary battery manufactured by the process of claim 16.
- 18. A method of manufacturing a non-aqueous secondary battery, comprising the steps of:
laminating graphite electrodes with a lithium group oxide; and enclosing said graphite electrodes into a cell vessel with an electrolyte solution, wherein
said graphite electrodes are manufactured by the steps of: granulating the graphite to graphite powder having a particle size equal to or smaller than 100 μm, (a) treating said graphite powder by heating at 900° C. or higher, after said granulating, or (b) immersing said graphite powder into an acidic solution as an immersing treatment, washing said graphite powder, neutralizing said graphite powder, and drying said graphite powder, and
after said (a) treating or said (b) immersing, fabricating said graphite powder electrodes by subjecting the heat-treated graphite powder to pressing.
- 19. A non-aqueous secondary battery manufactured by the process of claim 18.
Priority Claims (1)
Number |
Date |
Country |
Kind |
7-84196 |
Apr 1995 |
JP |
|
Parent Case Info
[0001] This application is a Divisional application of application Ser. No. 09/473,300, filed Dec. 28, 1999, which is a Divisional application of application Ser. No. 08/630,501, filed Apr. 10, 1996.
Divisions (2)
|
Number |
Date |
Country |
Parent |
09473300 |
Dec 1999 |
US |
Child |
10021093 |
Dec 2001 |
US |
Parent |
08630501 |
Apr 1996 |
US |
Child |
09473300 |
Dec 1999 |
US |