Nanofoil is a new nano–material and is made up of thousands of alternating nanoscale foils, which can be used in welding process. When nanofoil is applied in welding, firstly, the nanofoil is activated by a small energy pulse from electricity, light or heat sources, and then the temperature can be increased to about one thousand degrees in a fraction of a second. Compared with traditional welding methods, using nanofoil has many advantages in welding process. First, the whole system does not need to be heated and the welding process can be carried out at room temperature, which is conducive to saving resources. Second, nanofoil is able to weld together materials with different expansion coefficients, which can greatly expand the application range of welding technology. Thirdly, flux is not necessary during welding process. Therefore, no volatile matters are produced and the problem of residual flux does not exist, which can greatly improve the quality of welding products. Fourth, the voltage rate of the resulting weldment is low, usually less than 2%, which is very suitable for large area welding.
Figure 1. An example of nanofoil-based welding joint configuration.
Figure 2. Nanofoil applied in designing high performance Li storage materials.
Nanofoil is made up of thousands of nanoscale foils, which can be divided into many types depending on their composition. Nanofoil mainly includes ultra thin thorium nanofoil, ultra thin erbium nanofoil, cerium nanofoil, ultra thin aluminum nanofoil, ultra thin copper nanofoil, ultra thin nickel nanofoil and the others.