Binder-free Li₃V₂(PO₄)₃/C membrane electrode supported on 3D nitrogen-doped carbon fibers for high-performance lithium-ion batteries

An in-situ prepared binder-free Li₃V₂(PO₄)₃/C membrane electrode supported on 3D N-doped carbon fibers (LVP/C@NCF) has been developed. The residual carbon in LVP/C@NCF consists of the pyrolytic carbon from glucose and the N-doped carbon fibers decomposed from filter paper. The former uniformly covers on the surface of LVP particles, while the latter is functioned as both a 3D conductive network and a current collector for LVP. Compared with the traditional LVP/C electrode supported on Al foil (LVP/C@Al), the LVP/C@NCF membrane electrode displays higher rate capability and better cycle stability. Especially, when cycled at a high rate of 10 C, it still delivers a specific capacity as high as 107.6 mA h g⁻¹ with a very low capacity fading ratio of ~0.0048% per cycle after 1000 cycles. The excellent electrochemical performance is ascribed to the synergetic effect from the 3D effectively conductive network and the in-situ produced current collector of carbon fibers. The method of using filter paper as the source of carbon and current collector to prepare integrated membrane electrode may provide feasible and effective strategy to fabricate binder-free flexible and lightweight lithium ion batteries as well as sodium ion batteries.