Vapor selenization produced Bi2Se3 nanoparticles in carbon fiber 3D network as binder-free anode for flexible lithium-ion batteries

Abstract

Bi₂Se₃ is a promising anode material for lithium-ion batteries (LIBs) due to its high capacity and weak van der Waals stacking for Li-ion insertion. However, it suffers from low conductivity and structural instability during the Li-ion insertion and extraction processes. Herein, a new carbon nanofiber (CNF) network decorated with Bi₂Se₃ nanoparticles (∼40 nm) was facilely prepared and directly used as a binder-free flexible anode in LIBs. The Bi₂Se₃/CNFs anode delivered a high reversible gravimetric capacity of 443 mA h g⁻¹ after 260 cycles at 100 mA g⁻¹ and a rate capability of 103 mA h g⁻¹ at 16 A g⁻¹. The full cell with LiCoO₂ vs. Bi₂Se₃/CNFs  has a discharge specific capacity of 261 mA h g⁻¹ after 100 cycles at 100 mA g⁻¹. The excellent Li-storage performance is attributed to the Bi₂Se₃ nanoparticles uniformly embedded in the unique conductive 3D CNFs network which effectively improves the conductivity and avoids the layer structure collapse of Bi₂Se₃ materials. The synergistic effect of the enhanced characteristics successfully improved the long-term cycling and rate capability of the Bi₂Se₃ anode. This flexible and binder-free Bi₂Se₃/CNFs electrode has great potential as a neoteric anode material for LIBs.