Composite of Ge and α-MnSe in carbon nanofibers as a high- performance anode material for LIBs

Improving the performance of anode materials is of great importance for lithium-ion batteries (LIBs). Transition metal selenides compositing carbon and germanium (Ge) have attracted extensive attention. In this work, an anode material that integrates Ge and α-MnSe in carbon nanofibers (CNFs) was first synthesized by heat treatment after electrospinning. The coupling of Ge with α-MnSe and carbon can cause the growth process of α-MnSe to occur inside the CNFs, which can buffer the volume change, refine the grains and avoid particles protruding from the surface of CNFs. In addition, the interconnected conductive network of Ge/α-MnSe@CNFs can provide fast diffusion channels for Li ions and improve the electrical conductivity. Importantly, there is a synergistic effect of Ge, α-MnSe, and CNFs on the anode material for LIBs. As expected, Ge/α-MnSe@CNFs exhibited an excellent performance with a capacity of 1514.7 mAh g−1 after 200 cycles at 0.1 A g−1 and 1030 mAh g−1 after 1000 cycles even at 1 A g−1. Therefore, this new preparation strategy of Ge/α-MnSe@CNFs offers novel ideas to develop high-performance and long-life LIBs. •Ge/α-MnSe carbon nanofibers were first synthesized for lithium-ion batteries.•Coupling Ge with α-MnSe can help to limit the in-situ growth of α-MnSe inside CNFs rather than at the surface.•Ge/α-MnSe@CNFs showed a high capacity and long-time cycles life for LIBs.