Synthesis and electrochemical performance of a coaxial VGCF@ZnMnO₃ nanocomposite as a high-capacity anode material for lithium-ion batteries

Highlights: • A VGCF@ZnMnO₃ nanocomposite material is synthesized by hydrothermal reaction. • The composite has the features of coaxial structure and improved electric conduction. • The composite exhibits high performance of Li-storage as a high-capacity anode. • The synthetic method has the advantages of cost saving and environmental benignity. • A dissolution–recrystallization mechanism is proposed for the hydrothermal reaction. - Abstract: Transition metal oxides are considered promising high-capacity anode materials for lithium ion batteries (LIBs). However, their intrinsic low electric conductivity and large volumetric expansion/contraction during lithiation/delithiation can cause fast capacity degradation. Hence, modification of the electrode materials by appropriate structural design is important to their applications. Here, we present study on design, synthesis and Li-storage performance of a vapor grown carbon fiber (VGCF) enhanced VGCF@ZnMnO₃ coaxial-cable nanocomposite anode material for LIBs. This material is synthesized via a novel two-step strategy involving a crucial hydrothermal reaction between ZnO and prefabricated VGCF@δ-MnO₂ composite in pure water at 180 °C for 12 h. This composite material exhibits high specific capacity, good rate performance and excellent cycling performance. The exhibited high performance should be attributed to the improved electric conductance due to the incorporation of VGCFs and the particular architecture of one-dimensional nanocomposite. Additionally, the hydrothermal reaction mechanism is specially focused and preliminarily studied. A dissolution–recrystallization mechanism is proposed for the hydrothermal reaction.