Carbon foam and manufacturing method thereof

1. A carbon foam comprising linear portions and node portions joining the linear portions, wherein

the linear portions have a diameter of 0.1 μm or more and 10.0 μm or less,

the carbon foam has a surface with an area of 100 cm 2 or more,

the carbon foam has a three-dimensional network structure,

the carbon foam has a bulk density of 3.0 kgm −3 or more and 400 kgm −3 or less, and

the carbon foam has a porosity of 70% or more.

2. A carbon foam comprising linear portions and node portions joining the linear portions, wherein

the linear portions have a diameter of 0.1 μm or more and 10.0 μm or less,

the carbon foam has no through holes with an area of 2000 mm 2 or more,

the carbon foam has a three-dimensional network structure,

the carbon foam has a bulk density of 3.0 kgm −3 or more and 400 kgm −3 or less, and

the carbon foam has a porosity of 70% or more.

3. The carbon foam according to claim 2 , wherein the carbon foam comprises a region of 4000 mm 2 or more having no through holes with an area of 2000 mm 2 or more.

4. The carbon foam according to claim 2 , having no through holes with an area of 1000 mm 2 or more.

5. The carbon foam according to claim 2 , wherein at least a part of the carbon foam has a density of the node portions of 15,000/mm 3 or more.

6. The carbon foam according to claim 2 , wherein the linear portions have a diameter of 0.1 μm or more and 5.0 μm or less.

7. The carbon foam according to claim 2 , wherein at least a part of the carbon foam has a density of the node portions of 30,000/mm 3 or more.

8. The carbon foam according to claim 2 , wherein

in at least a part of the carbon foam, a thickness direction of the carbon foam is defined as x direction, a direction perpendicular to the x direction is defined as y direction, and a direction perpendicular to the x direction and the y direction is defined as z direction, and

for the linear portions in a region of 300 μm×300 μm×300 μm,

an average value of orientation angle with respect to the x direction is defined as θ avex ,

an average value of orientation angle with respect to the y direction is defined as θ avey , and

an average value of orientation angle with respect to the z direction is defined as θ avez , then

a difference θ d between the maximum value and the minimum value of the θ avex , the θ avey and the θ avez is 3° or more.

9. The carbon foam according to claim 1 , wherein the carbon foam comprises a region of 4000 mm 2 or more having no through holes with an area of 2000 mm 2 or more.

10. The carbon foam according to claim 1 , having no through holes with an area of 1000 mm 2 or more.

11. The carbon foam according to claim 1 , wherein at least a part of the carbon foam has a density of the node portions of 15,000/mm 3 or more.

12. The carbon foam according to claim 1 , wherein the linear portions have a diameter of 0.1 μm or more and 5.0 μm or less.

13. The carbon foam according to claim 1 , wherein at least a part of the carbon foam has a density of the node portions of 30,000/mm 3 or more.

14. The carbon foam according to claim 1 , wherein

in at least a part of the carbon foam, a thickness direction of the carbon foam is defined as x direction, a direction perpendicular to the x direction is defined as y direction, and a direction perpendicular to the x direction and the y direction is defined as z direction, and

for the linear portions in a region of 300 μm×300 μm×300 μm,

an average value of orientation angle with respect to the x direction is defined as θ avex ,

an average value of orientation angle with respect to the y direction is defined as θ avey , and

an average value of orientation angle with respect to the z direction is defined as θ avez , then

a difference θ d between the maximum value and the minimum value of the θ avex , the θ avey and the θ avez is 3° or more.