Shiyuan Zhu,Peng Liu,Qiongyu Zhou,Qianjun Deng,Yuanyuan Li,Jiacheng Wang,Zuo He,Changchun Tian,Xiaofen Wang
Zn coating is a typical anti-corrosion coating for carbon steel. Considering the sacrificial nature of Zn coating, it is essential to enhance the corrosion resistance for the long-term performance in the practical application. In this work, two-dimensional carbon nanoplatelets (2D-CNs) with nanometer thickness (∼100 nm) and ultra-large lateral size (10–40 μm) and Mn element have been successfully co-deposited with Zn onto low carbon steel by a simple electrodeposition method. Results show that the Zn-Mn/2D-CNs composite coating is composed of Zn phase, ZnMn 3 phase and a small number of 2D-CNs. The Zn-Mn/2D-CNs composite coating exhibits a modified surface quality with ultrafine grains and smaller roughness (Ra = 176 nm, Rq = 131 nm) when compared with that of Zn coatings (Ra = 798 nm, Rq = 684 nm). Besides, the inert 2D-CNs within the composite coating can act as the corrosion barriers. Therefore, the Zn-Mn/2D-CNs composite coating has excellent anti-corrosion performance, owning the lowest corrosion current densities i corr (9.2 μA cm −2 ) and maximum coating resistance R coat (1.2 kΩ·cm −2 ) and charge transfer resistance R ct (3.5 kΩ·cm −2 ), associated with its modified microstructure, Mn element with passivation property, and 2D-CNs barriers. These results demonstrate the desirable potentiality of inert 2D carbon materials in the electrodeposition of Zn-based coating for improving the corrosion resistance.
Large quantities of spent lithium-ion batteries (LIBs) will inevitably be generated in the near future because of their wide application in many fields. It will cause not only resource waste but also environmental pollution if these spent batteries are not properly handled. Until now, the recycling of spent lithium manganate batteries has centered on high-valuable elements such as lithium; however, manganese element and current collector Al foil have not yet attracted wide attention. In this work, aluminum-doped manganese dioxide was synthesized by overall recycling cathode active materials and current collector Al foil from a spent lithium manganate battery. Employing such aluminum-doped manganese dioxide as the cathode material of aqueous Zn batteries, it displays better electrochemical performance than manganese dioxide prepared by only recycling the cathode active materials. The overall recycling not only simplifies the recycling process but also realizes high-value recycling of spent lithium manganate batteries. We offer new tactics for overall recycling of cathodes from spent LIBs and designing high-performance manganese dioxide cathodes for aqueous Zn batteries.