Application of Spent Li-Ion Batteries Cathode in Methylene Blue Dye Discoloration

Abstract

This paper aims to present the mechanism study of methylene blue (MB) discoloration using spent Li-ion battery cathode tape and hydrogen peroxide. The recycled cathode used in this work is composed of 72% of LiCoO 2 , 18% of carbon, and 10% of Al. The value found for surface area is 8.9 m 2 /g and the ZCP value occurs in pH = 2.95. Different from what is proposed in the literature, the most likely mechanism of methylene blue discoloration is the oxidation/delitiation of LiCoO 2 and the reduction of H 2 O 2 forming OH• . Thus, in this paper, an important and promising alternative for discoloration of textile industry dyes using spent Li-ion battery cathode is presented.

Fast Electrochemical Method for Organic Dye Decolorization Using Recycled Li-Ion Batteries

“…In this case, the OH• radical formation occurs through LiCoO2 delitiation promoted by the hydrogen peroxide reduction in (Equation (2)) [11]. The formation of the hydroxyl radical (OH•) was confirmed utilizing isopropanol (i-PrOH) as a scavenger [11].…”

“…A schematic showing the main parts of the Li-ion battery is shown in Figure 1. The spent Li-ion battery cathode (LIB-SC) tape was washed in distilled water to eliminate possible lithium salts (such as LiPF 6 ) present in the electrolyte [11]. The crystalline structure of the spent Li-ion battery cathode tape was characterized by X-ray diffraction on a 200 B Rotaflex-Rigaku with Cu K α irradiation, a Co filter, and a scanning speed of 0.02 min −1 .…”

“…The decolorization process was monitored by analyzing aliquots at 659 nm using a UV-Spectrophotometer FEMTO Cirrus 80 PR. All measurements were made in the absence of visible light to avoid the possible electron excitation of the cobalt lithium oxide conduction band to the valence band generating the electron (BC) and hole (BV) pair [11].…”

“…Components such as Co and Li are recovered in forms such as Co(OH) 2 and Li 2 CO 3 , and even the resynthesis of cathodic material has been proposed [9]. Although there are many studies on LIB/SC recycling, very few studies focus on the direct application of LIB/SC [11].…”

“…The recent literature describes the decolorization of methylene blue (MB) solution using LIB/SC (with LiCoO 2 ) in the presence of H 2 O 2 [11]. In this case, the OH• radical formation occurs through LiCoO 2 delitiation promoted by the hydrogen peroxide reduction in (Equation (2)) [11]. The formation of the hydroxyl radical (OH•) was confirmed utilizing isopropanol (i-PrOH) as a scavenger [11].…”