Diffusion in metals occurs when individual atoms or ions move from one location to another within the metal's crystal lattice, involving the movement of atoms from lattice sites to nearby vacant sites as well as migrating into interstitial sites between existing lattice atoms. This process happens due to thermal energy, which causes the atoms or ions to vibrate. When atoms gain sufficient energy, they can overcome the forces holding them in place and move to neighboring lattice sites. The diffusion of atoms in metals is influenced by various factors, including temperature, concentration gradients, and the presence of defects in the crystal lattice. At higher temperatures, atoms have more thermal energy, leading to increased diffusion rates. Concentration gradients also drive diffusion, as atoms tend to move from regions of higher concentration to regions of lower concentration to achieve a more uniform distribution. Diffusion in metals plays a crucial role in determining material properties, such as hardness, electrical conductivity, and corrosion resistance. For metal anodes in batteries, it should be mentioned that there is no mobility needed as the metal anode is either formed or dissolved upon charging or discharging, respectively.