Mn₂SiO₄/CNT composites as anode materials for high performance lithium-ion batteries

Mn₂SiO₄/CNT composite, which is constructed with polyhedron-shaped particles embedded in the carbon nanotube (CNT) network, has been synthesized by a sol–gel method. The as-prepared Mn₂SiO₄ presented a well-developed orthorhombic crystal structure, and after modified with CNT, the compound exhibited excellent rate capability and cyclic performance as anode materials for lithium ion batteries. Galvanostatic charge–discharge measurements demonstrated outstanding initial charge and discharge capacity of 664.8 and 392.1 mA h g⁻¹ at the current density of 100 mA g⁻¹, respectively, and stable reversible capacity of 466.9 mA h g⁻¹ was retained after 40 cycles. Even at a high current density of 2000 mA g⁻¹, Mn₂SiO₄/CNT can deliver the specific capacity of 205.8 mA h g⁻¹. Also, the reaction mechanism of this material is speculated including the formation of Li₂SiO₃, MnO and Mn. In addition, the significant change of charge transfer resistance compared with pristine Mn₂SiO₄ confirmed by electrochemical impedance spectroscopy illustrated the fast Li ions intercalation kinetics and reduced electrochemical polarization via CNT modification, suggesting Mn₂SiO₄/CNT to be promising anode materials for high performance lithium ion batteries.