Mn ₃ O ₄ /carbon nanotube nanocomposites recycled from waste alkaline Zn–MnO ₂ batteries as high‐performance energy materials

Abstract

Abstract Alkaline zinc manganese dioxide (Zn–MnO 2 ) batteries are widely used in everyday life. Recycling of waste alkaline Zn–MnO 2 batteries has always been a hot environmental concern. In this study, a simple and cost‐effective process for synthesizing Mn 3 O 4 /carbon nanotube (CNT) nanocomposites from recycled alkaline Zn–MnO 2 batteries is presented. Manganese oxide was recovered from spent Zn–MnO 2 battery cathodes. The Mn 3 O 4 /CNT nanocomposites were produced by ball milling the recovered manganese oxide in a commercial multi‐wall carbon nanotubes (MWCNTs) solution. Scanning electron microscopy (SEM) analysis demonstrates that the nanocomposite has a unique three‐dimensional (3D) bird nest structure. Mn 3 O 4 nanoparticles are homogeneously distributed on MWCNT framework. Mn 3 O 4 /CNT nanocomposites were evaluated as an anode material for lithium‐ion batteries, exhibiting a highly reversible specific capacitance of ~580 mAh·g −1 after 100 cycles. Moreover, Mn 3 O 4 /CNT nanocomposite also shows a fairly positive onset potential of −0.15 V and quite high oxygen reducibility when considered as an electrocatalyst for oxygen reduction reaction.