A Review on the Electroless Deposition of Functional Materials in Ionic Liquids for Batteries and Catalysis

Abstract

Developing functional materials via electroless deposition, without the need of external energy is a fascinating concept. Electroless deposition can be subcategorized into galvanic displacement reaction, disproportionation reaction, and deposition in presence of reducing agents. Galvanic displacement reaction is a spontaneous reduction process wherein the redox potentials of the metal/metal ion in the electrolyte govern the thermodynamic feasibility of the process. In aqueous solutions, the galvanic displacement reaction takes place according to the redox potentials of the standard electrochemical series. In comparison, in the case of ionic liquids, galvanic displacement reaction can be triggered by forming metal ion complexes with the anions of the ionic liquids. Therefore, the redox potentials in ILs can be different to those of metal complexes in aqueous solutions. In this review, we highlight the progress in the electroless deposition of metals and semiconductors nanostructures, from ionic liquids and their application toward lithium/sodium batteries, and in catalysis.

Keywords: batteries; catalysis; electroless deposition; galvanic displacement; ionic liquids.

Figure 1

Schematic diagram of various electroless deposition processes (A) Galvanic displacement reaction (B) Reduction using reducing agents (C) Disproportionation reaction.

Figure 2

(A) 3D AFM image of electroless deposited Ag on Cu (B) AFM height profile of the electroless deposited Ag on Cu shown in Figure 1A (C) Ag deposited on a printed circuit board. Reproduced from Abbott et al. (2007) and Abbott et al. (2008) with permission from The Royal Society of Chemistry and Elsevier.

Figure 3

(a) Electroless deposition of Au on nickel from (a1) AuCl (a2) AuCN (a3) KAu(CN)₂ in ChCl-1, 2-ethanediol (b) Electroless deposition of Au from H[AuCl₄] in EMImTFSA in presence of HTFSA on glassy carbon (c) Gold nanoplates formed by electroless deposition on glassy carbon from H[AuCl₄] in EMImTFSA in presence of HTFSA (d) Electroless deposition of Pt nanoparticles (e) Methanol electrooxidation on Pt nanoparticles formed by electroless deposition. Reproduced from Aldous et al. (2007), Zhang et al. (2013) and Ballantyne et al. (2015) with permission from The Royal Society of Chemistry and American Chemical Society, Copyright 2007, 2013 American Chemical Society.

Figure 4

(A) Microstructure of electrodeposited Al from [EMIm]Cl/AlCl₃ at −0.3 V vs. Al and (B) from [Py_1,4]Cl/AlCl₃ at −0.3 V vs. Al for 1 h (C) Al electroless deposited from [EMIm]Cl/AlCl₃ in presence of LiH as reducing agent. Reproduced from Koura et al. (2008) with permission from The Electrochemical Society.

Figure 5

(A) Microstructure of Sb modified Ge nanoparticles (B) Raman spectra of electrodeposited Ge (black line), electroless deposited Sb on Ge (red line) and after annealing to 300°C (blue line) (C) SEM of electroless deposition Sb on silicon (D) Charge-Discharge cycles of electrodeposited Ge and Sb modified Ge for Na-ion batteries in 1 M NaFSA-[Py_1,4]FSA (E) Charge-Discharge cycles of electrodeposited Si and Sb modified Si for Li-ion batteries in 1 M LiTFSA-[Py_1,4]TFSA. Reproduced from Lahiri et al. (2016) and Lahiri et al. (2017) with permission from The Royal Society of Chemistry and American Chemical Society. Copyright 2017 American Chemical Society.