Nanosized α-MnS homogenously embedded in axial multichannel carbon nanofibers as freestanding electrodes for lithium-ion batteries

Abstract

To buffer the unavoidable volume expansion and structure collapse problems of transitional metal sulfides during lithiation process, herein, nanosized α-MnS homogenously embedded in axial multichannel carbon nanofibers was well designed and directly used as freestanding anodes for lithium-ion batteries (LIBs). The obtained carbon nanofibers were interwoven into a flexible and cross-linked film, which offered a 3D successive conductive networks and guaranteed sufficient contact interface for electrode/electrolyte. The nanosized α-MnS was homogenously embedded into the carbon nanofiber framework and surrounded with a thin protective carbon layer, which effectively maintained the structural integrity for a satisfied cycling performance. The high aspect ratio carbon nanofibers with axial open channels supplied sufficient active sites and formed long-range electronic pathways along the axial carbon wall. Meanwhile, the radial voids provided enormous accommodation space to alleviate volume expansion and shortened diffusion paths for faster ionic transfer. Benefitting from the above unique merits, the freestanding electrodes delivered excellent lithium storage performances and remarkable long-term cycling stability, including a high initial reversible capacity of 772 mAh g−1 and excellent cycling capacity retention of 93.4% after 100 cycles at a current density of 0.5 A g−1.