Electrodeposition of Sn powders with pyramid chain and dendrite structures in deep eutectic solvent: roles of current density and SnCl2 concentration

Tin (Sn) powders with pyramid chain and dendrite structures are successfully prepared by electrodeposition in choline chloride-ethylene glycol deep eutectic solvent (ChCl-EG DES) at 343 K. Cyclic voltammetry demonstrates that increasing SnCl 2 concentration from 30 to 70 mM is favorable for the reduction of Sn(II) ions to metallic Sn on Ni electrode. The roles of current density (10–30 mA·cm −2 ) and SnCl 2 concentration (30–70 mM) on the current efficiency and energy consumption are discussed during the electrodeposition of Sn powders. Experimental results show that the current efficiency and energy consumption are 88.7% and 347.1 kW·h·t −1 , respectively at 20 mA·cm −2 and 50 mM SnCl 2 . Besides, the micromorphology and crystal structure of Sn powders are analyzed by FESEM and XRD. Morphology analysis manifests that pyramid chains and dendrites in length of 30–220 μm are the dominate morphologies and the formation mechanism of the pyramid chain is also discussed. Moreover, XRD analysis and crystal texture reveal that metallic Sn is obtained with a body-centered tetragonal crystal structure. The (101) plane is the preferred at higher current density, while the (200) plane gets the strongly preferred orientation as SnCl 2 concentration increases. Graphical abstract Sn powders electrodeposited from SnCl 2 -ChCl-EG solution and growth mechanism of the pyramid chain structure.