The study of electrochemical stabilization mechanism of Pt, GC, SS304, Ti and Cu as current collectors for aqueous lithium-ion batteries by electrochemical approaches

Abstract

This paper employs electrochemical methods (linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS)) to investigate the electrochemical behavior of platinum, glassy carbon, 304 stainless steel, titanium, and copper in 21 and 1 M LiTFSI electrolytes. The LSV results indicate that the electrochemical stability window of the materials varies with the electrolyte concentration, and the stability window is wider in the high-concentration system. Through Tafel polarization curves and EIS analysis, the overpotential of the charge exchange process differs due to the type of material and the concentration of the electrolyte, mainly attributed to the influence of the proportion of free water, electrolyte viscosity, and SEI film formation on electrode process kinetics. After comparative analysis, glassy carbon exhibits a higher overpotential than other materials at both the cathode and anode, effectively suppressing water decomposition. These findings provide theoretical support for the development of high-performance aqueous lithium-ion battery current collector materials.