SYNTHESIS AND CHARACTERIZATION OF MULTIFUNCTIONAL MATERIALS FROM THE RECOVERY OF METALS FROM Li-ION AND Zn–MnO2 BATTERIES
Name: FERNANDO SILVA BETIM
Publication date: 27/03/2023
Examining board:
Name |
Role |
|---|---|
| ERIC MARSALHA GARCIA | Examinador Externo |
| MARCOS ANTONIO RIBEIRO | Examinador Interno |
| MARCOS BENEDITO JOSE GERALDO DE FREITAS | Presidente |
| MARIA DE FATIMA FONTES LELIS | Examinador Interno |
| VITOR CEZAR BROETTO PEGORETTI | Examinador Externo |
Summary: This study evaluated the recovery of high-added-value metals from lithium-ion batteries and alkaline Zn–MnO2 batteries in oxides form. The cathodes of LIBs and alkaline batteries were leached with citric acid and glucose, while the anode of alkaline
batteries was leached with citric acid and H2O2. The LIBs anode was leached with acetic acid and H2O2. From the mixture of these leachates, followed by the technique of coprecipitation with oxalic acid, followed by calcination, it was possible to synthesize the oxides Co, Mn–Co, Zn–Co, and Cu–Co. From the characterization techniques, it was possible to verify the formation of oxide nanoparticles with mixed composition, in the range of 20–50 nm, being assigned the phases Co3O4, Li(Mn0.75Ni0.25)2O4 and Mn3O4 for the Co oxide; MnCo2O4, Li(Mn0.75Ni0.25)2O4 and Mn3O4 for Mn–Co oxide;
ZnCo2O4, Li(Mn0.75Ni0.25)2O4 and ZnO for Zn–Co oxide; and Cu0.76Co2.24O4, CuO, and CuNi0.5Mn1.5O4 for Cu–Co oxide. A second recycling route consisted of leaching the anode of LIBs with citric acid and H2O2, leading to a metallic citrate. After calcination, Cu oxide was formed, composed of nanoparticles in the range of 20–50 nm of CuO, in addition to the presence of graphite and traces of Li. Finally, by washing the Zn–MnO2 alkaline cell anode in a 1 mol L-1 citric acid solution, followed by thermal treatment, it was possible to obtain the oxides Zn–80, Zn–450, and Zn–700. From the characterization techniques, these oxides were characterized as ZnO microparticles. Co, Mn–Co, Zn–Co, and Cu–Co oxides were evaluated as catalysts in a photo-Fenton type process for methylene blue decolorization, with the last three with, respectively, 93.0%, 94, 3%, and 89.7% efficiency after 120 minutes. Cu and Cu–Co oxides were evaluated as pseudocapacitors. The Cu oxide presented specific capacitance of 9.1 Fg-1 after 500 cycles of galvanostatic charge and discharge at a current density of 0.75 A g-1, with charge/discharge efficiency of 17.2 %, indicating low electrochemical reversibility of the material. Cu–Co oxide presented specific capacitance of 28.8 F g-1
after 500 cycles of voltammetry at a speed of 20 mV s-1 , with charge/discharge efficiency of 84.9%, indicating good reversibility of the system. Finally, the oxides Zn–Co, Cu–Co, Zn–80, Zn–450, and Zn–700 were evaluated as catalysts in the PET
degradation reaction by glycolysis, with the last three with, respectively, 99.34%, 96 .95% and 95.51% efficiency. The results showed that the compounds synthesized from metals recovered from lithium-ion and alkaline Zn–MnO2 batteries shown potential in the studied applications. The work presents alternatives for recovery of metals from lithium-ion batteries and alkaline Zn–MnO2 batteries, with results of economic, environmental, scientific, and social interest.
