Metal foams

Fig. 1. Schematic illustration of possible application energy areas for Cu, Ni, and Co foams fabricated in this study

Anode current collector using Cu or Co foam

coated with an active material

Dye-sensitized solar cells Li-ion batteries Solid oxide fuel cells

Anode current collector using Ni foam

after surface modification

Counter electrode using Ni foam

after nitriding process

20 µm 200 µm

20 µm

Cu foam

Ni foam Co foam

20 µm

Side view

Metal foam

Fig. 2. SEM images of Cu, Ni, and Co foams fabricated by freeze-casting and reduction in this study

–  Freeze-cast metal foams created by novel process (freeze casting and reduction) with elongated, aligned pores

–  Elongated pores (few ten of microns in width and millimeters in length) for high permeation of electrolyte

–  High surface area for fast reaction at electrodes

–  Pores help buffer lithiation stresses in lithium ion battery

–  Use as electrode in various energy areas such as Li-ion battery, dye-sensitized solar cell, and fuel cells