Enhancing electrochemical properties of commercial lithium titanate using cuprous chloride nanoparticle-modified copper foil current collectors

Abstract

For the first time, CuCl nanoparticles were fabricated at ambient temperature onto the surface of a copper (Cu) foil current collector through using an immersing approach, in which the immersing solution only contained 0.6 M CuSO4 and a very small amount of hexadecyl trimethyl ammonium chloride (HTAC). For simplicity, all as-prepared CuCl nanoparticles modified copper foils were labeled as CuCl/Cu. The specimens of CuCl/Cu prepared in the presence of 4 mM, 8 mM and 12 mM HTAC were designated as specimen a, b and c, respectively. The lithium titanate (Li4Ti5O12, LTO) electrodes assembled using the as-prepared CuCl/Cu exhibited an outstanding electrochemical performance as compared to the conventional LTO electrode manufactured using the commercial bare copper foil. Such as, the initial discharge capacity (DC) value of the LTO electrode assembled using specimen b at 0.2 C was measured to be 216 mAh g−1, which was about 1.3 times that of the conventional LTO electrode (165 mAh g−1). More importantly, at 10 C after 100 cycles, the DC value of the LTO electrode assembled using specimen b was retained to be as high as 143 mAh g−1, being about 3.1 times higher than that of the conventional LTO electrode (46 mAh g−1). A room temperature immersing approach for preparing CuCl nanoparticles and a novel method to significantly improve the electrochemical behavior of the conventional LTO electrode are developed in this work, which is very meaningful not only to the development of CuCl related material science but also to the further progress of LTO based lithium ion batteries (LIBs).