• Energy Research

Metals such as nickel, cobalt, lithium, and manganese are widely used in lithium-ion batteries (LIBs) in electronic devices and electric vehicles. It is forecast that there will be a strong increase in the number of electronic devices and electric vehicles in the coming years. (1) Background: In this paper, the application of ultrasound waves on improving Li, Co, Mn, and Ni leaching efficiency from mixed active cathode materials from different types of LIBs is presented. (2) Methods: Environmentally friendly, low-concentrated (0.75 M) organic acids (oxalic acid, citric acid) and, additionally, sulfuric acid, were used in sonochemical and chemical leaching (stirring process) at a temperature of 60 °C. (3) Results: The results showed significantly higher leaching efficiency of metals with ultrasound-assisted treatment, especially when using organic acids. An average of 50% better leaching results were obtained for Li in oxalic acid (99.6%) and for Co (93.1%) in citric acid during sonochemical leaching. (4) Conclusions: Based on the theory of hydrogen peroxide formation during ultrasound wave transition in solutions, the role of H2O2 as one of the most effective reductants used to enhance cobalt, manganese, and nickel leaching from LIBs is indicated.

Energy transition is one of the basic actions taken to counteract and prevent climate change. The basic assumption of energy-related changes is its sustainable use according to the closed-loop model, as well as moving away from fossil fuels, in particular from coal, the combustion of which contributes to excessive harmful carbon dioxide emissions. One of the most popular solutions towards green energy is nuclear energy. Its use allows for a significant reduction in greenhouse gas emissions harmful to the environment and climate, but it also involves the generation of radioactive waste that requires appropriate processing. This paper presents the results of the flotation removal of barium(II) ions from a dilute aqueous solution using ionized acyclic polyethers. The basic factors determining the efficiency and kinetics of the process were defined. It has been shown that as the acidity of the attached polyether molecules increases: the flotation rate constant 1 (0.1667 min−1) < 3 (0.2468 min−1) < 2 (0.3616 min−1) and the separation degree Ba2+: 1 (86.8%) < 3 (99.3%) < 2 (99.4%). The presented results of ion flotation tests may facilitate the collective or selective separation of radioactive isotopes, i.e., Cs-137, Sr-90, Ba-133 and Co-60, from radioactive wastewater in the future. The results of the experimental work described in the article can also be used to develop individual processes for separating mixtures of radioactive isotopes (radioactive wastewater) into individual components (isotopes) and subjecting them to subsequent transformation processes. The obtained results allow us to claim that the tested organic compounds can be used in the future in the selective treatment of hazardous wastewater, which will translate into a reduction in unit costs of industrial processes. The selective recovery of individual pollutants is the basis for the next step in waste management, i.e., designing a cheap method of waste disposal, which also directly affects the economics of the process and its use in industrial conditions.