In-situ synthesis of carbon coated Li2MnSiO4 nanoparticles with high rate performance

Abstract

In-situ coating approach using phenolic resin as carbon source is introduced in this work with the aim of getting high rate Li2MnSiO4/C composite. Li2MnSiO4/C nanoparticles, average diameter of ca. 25 nm, are well dispersed and the carbon layers are 3–8 nm in thickness. The composites deliver much higher electrochemical performance than those using sucrose as carbon source, in terms of reversible discharge capacity and cycling performance. High rate performance is also observed. It exhibits high reversible capacities of 181.6, 149.1, 133.5 mAh g−1 at 0.4, 1.2 and 2 C, respectively. At 4 C-rate, the electrode still maintains a discharge capacity of 108.7 mAh g−1, around 52.5% of its capacity at 0.1 C. Apparently, in-situ synthesis of carbon coated Li2MnSiO4 using phenolic resin as carbon source results in thin and homogeneous carbon layer with relatively high sp2/sp3 ratio, as well as the limited particle size, which are the main reasons for the superior rate capability.