Electrospun Ti3C2T x MXene and silicon embedded in carbon nanofibers for lithium-ion batteries

Abstract

In spite of outstanding theoretical specific capacity (∼3590 mAh g−1), huge volume change during lithiation/delithiation and poor conductivity hinder the practical applications of pure Si anodes for lithium ion batteries (LIBs), requiring conductive additives and porous architectures. In this work, flexible and freestanding composite films made of two-dimensional Ti3C2T x MXene nanosheets and silicon particles embedded in carbon nanofiber (denoted as Ti3C2T x -Si@CNF) were prepared via electrospinning and used as LIB anodes. This new electrode design provides a 3D network architecture and high conductivity favorable for good electrochemical performance and long cycle life. Ti3C2T x -Si@CNF electrodes, containing 28% silicon retained high specific capacity of ∼1580 mAh g−1 after 100 cycles at 0.1 A g−1 and 720 mAh g−1 after 1000 cycles at 1 A g−1, and delivered a great rate performance with 289 mAh g−1 at a current density of 5 A g−1. This is a significantly enhanced performance compared with Si particles embedded in CNF without Ti3C2T x (denoted Si@CNF). This work proposes a scalable manufacturing strategy for developing high-performance silicon-based anodes, overcoming the low conductivity and volume expansion issues.