Film-like graphite, manufacturing method for same, and battery using same
AssigneeMitsubishi Chemical Corporation
InventorsKenji Hirano, Keisuke Wada, Tomoyoshi Yamashita, Norimichi Kawabe, Takuya Suzuki, Miwa Yanagidate, Kouhei Takatani
Life of this patent
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Abstract
A film-like graphite that satisfies the following condition (1) or condition (2) described below. Condition (1): a graphite crystal orientation degree P is 96% or more with respect to a film plane. Condition (2): a graphite crystal orientation degree P is 94% or more with respect to a film plane and a thickness is 42 μm or more.
Claims30
A film-like graphite, satisfying condition (1) or condition (2):
- Condition (1):
- a graphite crystal orientation degree P is 96% or more and less than 100% with respect to a film plane, and a thermal conductivity b is 1,550 W/mK or more;
- or
- Condition (2):
- a graphite crystal orientation degree P is 94% or more and less than 100% with respect to a film plane and a thickness is 42 μm or more and 250 μm or less, and a thermal conductivity b is 800 W/mK or more.
A film-like graphite, satisfying condition (3) or condition (4):
- Condition (3):
- a film thickness a is 58 μm or more and a thermal conductivity b is 1,550 W/mK or more in a direction along a film plane;
- or
- Condition (4):
- a film thickness a is 50 μm or more, a thermal conductivity b is 1,550 W/mK or more in a direction along a film plane, and a×b≥100,000.
A film-like graphite, wherein an a×b product of a film thickness a in μm, and a thermal conductivity b in W/mK, in a direction along a film plane, is 88,000 or more and 500,000 or less, and a thermal conductivity b is 1,550 W/mK or more.
A film-like graphite, wherein a number N of a plurality of bright regions obtained from an image in a vertical cross-section of the film-like graphite with respect to a film plane, in which bright parts and dark parts observed in a polarization microscope image are binarized, a film thickness H in μm, and a film width W in μm, satisfy expression (7) or (8) and (9)
- N/H/W≤0.015 (7),
- N/H/W≤0.04 (8),
- H≥42 (9).
A film-like graphite, wherein an average area of a plurality of bright regions obtained from an image in a vertical cross-section of the film-like graphite with respect to a film plane, in which bright parts and dark parts observed in a polarization microscope image are binarized, is 22 μm2 or more, or
- wherein a film thickness is 42 μm or more and the average area is 9 μm2 or more.
A method for manufacturing a film-like graphite, the method comprising:
- carbonizing a raw film made of an organic polymer to obtain a carbonized film;
- and
- graphitizing the carbonized film to obtain a graphitized film,
- wherein a film-like graphite that has a thermal conductivity of 800 W/mK or more and a minimum bending radius of 16 mm or less according to a bend test is manufactured from the raw film that has a thickness of 150 μm or more and 450 μm or less at a maximum value in a temperature increase range of 60° C. or higher during optional 30 minutes in a temperature increase pattern obtained by a monotonic temperature increase in a temperature increase history of 2,000° C. or higher in the graphitizing.
A method for manufacturing a film-like graphite, the method comprising:
- of carbonizing a raw film, made of an organic polymer and having a thickness of 70 μm or more, to obtain a carbonized film;
- and
- graphitizing the carbonized film to obtain a graphitized film,
- wherein the carbonizing comprises heating the raw film in a mixed gas comprising (a-1) acetylene and/or (a2) an acetylene derivative and (b) an inert gas.
A manufacturing method for manufacturing a film-like graphite, the method comprising:
- carbonizing a raw film, made of an organic polymer and having a thickness of 120 μm or more, to obtain a carbonized film;
- graphitizing the carbonized film to obtain a graphitized film having a density of less than 1.7 g/cm3;
- and
- compressing or rolling the graphitized file to obtain the film-like graphite, having a density of 1.7 g/cm3
- wherein an Sg/Sm ratio of an area Sg of the graphitized film to an area Sm of the raw film is 0.8 or more.
Dependencies are inferred from the claim text.