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The synergistic inhibitive effect of cysteine (Cys) and iodide ions on the corrosion behavior of copper was examined in a 0.5 mol·L−1 Na2SO4 solution. Potentiodynamic polarization curve revealed that Cys acted as a mixed type inhibitor with a major effect on the cathodic process, consequently decreased the corrosion current density by a great extent and shifted the corrosion potential negatively. The investigated results suggested that iodide ions can enhance the inhibition efficiency of Cys. The inhibition mechanism of Cys and the synergistic effect of the two examined reagents were investigated by fitting experimental impedance data according to a projected equivalent circuit for metal/electrolyte interface. Surface analysis further confirmed that the corrosion inhibition was realized due to the adsorption of the inhibitor molecules at the metal/solution interface. Langmuir adsorption isotherm was proposed to describe inhibition mechanism of Cys on copper surface. Active sites of Cys molecule were used to form inhibitor film on the copper surface. Addition of iodide ion increased its inhibition efficiency by enhancing adsorption of Cys cations through electrostatic interaction with I− pre-adsorbed on Cu surface. [ABSTRACT FROM AUTHOR]

To realize the high value–added utilization of acid-washed iron red, in this paper, acid-washed iron red is used as raw material. Aiming at the problem of low conductivity of iron-based lithium ion batteries (LIBs) LiFePO4/C materials, different metal ions are doped in the iron position, and the microstructure and electrochemical properties of the obtained material are systematically studied. Here, LiFePO4/C is synthesized through simple carbothermal reduction method using acid-washed iron red as the iron source. On this basis, La (1%, 2%, 3%) doping modification is carried out. Then doped modification is performed on this basis, preferably 2% La-doped LiFePO4/C materials. The XRD patterns show that the diffraction peaks of the samples prepared at all doping amounts can be perfectly matched with the standard card (PDF # 40–1499), and there is no impurity peak, all of which are pure phases. According to the refined data, it is clear that minor amount of La has successfully replaced the position of Fe and incorporated into the lattice. Electrochemical tests show that LiFe0.98La0.02PO4/C has the highest charge and discharge capacity of 146.5/138.2 mAh·g−1 in the first cycle at 0.5C, and the reversible specific capacity of 136.5 mAh·g−1 remains after 50 cycles. Furthermore, the first-principles calculations more strongly confirm that La doping can significantly improve the defects of low electronic conductivity of LiFePO4. [ABSTRACT FROM AUTHOR]

In order to better recycle and reuse metal ions in metallurgical industrial waste and reduce the production cost of lithium-ion batteries (LIBs). In this paper, carbon-coated LiFePO4/C cathode materials are synthesized through the carbothermal reduction method using acid-washed iron red as raw material. In order to make LiFePO4/C exhibit satisfactory electrical properties, the rare earth element Eu is doped in the Fe position, and the doping amount is optimized. The influence of the double coupling effect of coating and doping on the structure and properties of LiFePO4 cathode materials is systematically discussed. The local XRD results of the doped samples show that the diffraction peaks of the doped samples move to the small angle grain boundaries, and the lattice spacing of the materials increases, which is due to the large radius of Eu ions. The experimental results show that the dual coupling of carbon coating and ion doping can improve the conductivity of LiFePO4 cathode materials and improve its electrochemical performance. When the doping amount of Eu is 2%, the electrochemical performance of LiFe0.98Eu0.02PO4/C cathode material is the best. The initial charge–discharge capacity of 153/144.4 mAh·g−1 can be obtained at 0.5C, and a discharge capacity of 143.2 mAh·g−1 remains after 50 cycles. The exploration of this experiment provides a reasonable solution for slowing down the pollution of metallurgical waste to the environment and reducing the production cost of LIBs. [ABSTRACT FROM AUTHOR]

ZnMn2O4 anode material with nanosheet lamellar structure was synthesized using microwave method. The bearing of reaction temperature, reaction time, reactant compactness, and pH of the synthesis environment on the discharge–charge performance of samples were systematically studied. It is confirmed that ZnMn2O4 material presents a nanosheet lamellar structure with a uniform distribution. When the reaction temperature is 200℃, the reaction time is 25 min, reactant compactness is 73%, pH is 7, and initial discharge-specific capacity of the samples is 959.6 mAh·g−1. After 40 cycles, the capacity remains at 346.9 mAh·g−1, and the coulomb efficiency is stable at 100%. Spinel ZnMn2O4 anode material was microwave hydrothermally synthesized from zinc nitrate and manganese nitrate as raw materials in an aqueous solution. The material has a nano lamellar structure and shows good electrochemical properties as anode material of lithium-ion batteries. [ABSTRACT FROM AUTHOR]