Battery Anodes Prepared by Electrodeposition in Tin(II) Chloride-Based Deep Eutectic Solvent on Copper Foam

L. A. AZPEITIA; TSUNODA S.; M. G ORTIZ; RODRIGUEZ PRESA M.J; A. VISINTIN; C. A. GERVASI; A. E. BOLZÁN

Mar del Plata

Congreso; the 34th Topical Meeting of the International Society of Electrochemistry; 2023

INTEMA- Universidad Nacional de Mar del Plata

Deep eutectic solvents (DES) are currentlyconsidered as strategic green solvents for different electrochemical processes relevantto some important technological applications[1]. Among the differentcombinations of hydrogen bond donor/acceptor molecules, the mixture of aquaternary salt and a metal halide can provide a cost-effective efficient substitutefor conventional solvents. Accordingly, the electrodeposition of tin from aSnCl2-based DES was investigated by using as substrates either copperfoils or copper foams. The electrochemical properties of the electrodes wereexamined in the role of anodes for Li-ion batteries. Synthesis of copper foamsubstrates was performed under galvanostatic conditions under a strong hydrogenevolution in an acid aqueous copper sulphate solution. A significantimprovement in the mechanical properties of the obtained foams was achieved bymeans of a heat treatment. Galvanostatic tin electrodeposition was studied in cholinechloride + tin chloride 1:2 molar DES by applying square wave signals with varyingcurrent levels and step durations. A thin film of electroreduced graphene oxidewas deposited by the drop casting method on copper surfaces prior to tinelectrodeposition. The presence of this film should prevent diffusion of tinatoms into the copper lattice, with subsequent formation of intermetallics, andhelp to reduce the proper electrode mechanical stress during the lithiumintercalation process. Additionally, the study was extended to the synthesis ofSnO2 anodes by electro-oxidation of the Sn anodes in 0.05M KClO4aqueous solution by means of a periodic symmetric galvanostatic routine. Resultsshow significant improvement on going from a smooth surface to the foam 3Dstructure and from tin to a tin oxide electrode.