Core-shell structured MnSiO₃ supported with CNTs as a high capacity anode for lithium-ion batteries

Metal silicates are good candidates for use in lithium ion batteries (LIBs), however, their electrochemical performance is hindered by their poor electrical conductivity and volume expansion during Li+ insertion/desertion. In this work, one-dimensional core-shell structured MnSiO3 supported with carbon nanotubes (CNTs) (referred to as CNT@MnSiO3) with good conductivity and electrochemical performance has been successfully synthesized using a solvothermal process under moderate conditions. In contrast to traditional composites of CNTs and nanoparticles, the CNT@MnSiO3 composite in this work is made up of CNTs with a layer of MnSiO3 on the surface. The one-dimensional CNT@MnSiO3 nanotubes provide a useful channel for transferring Li+ ions during the discharge/charge process, which accelerates the Li+ diffusion speed. The CNTs inside the structure not only enhance the conductivity of the composite, but also prevent volume expansion. A high reversible capacity (920 mA h g-1 at 500 mA g-1 over 650 cycles) and good rate performance were obtained for CNT@MnSiO3, showing that this strategy of synthesizing coaxial CNT@MnSiO3 nanotubes offers a promising method for preparing other silicates for LIBs or other applications.