Improved electrochemical performance of zinc oxide coated lithium manganese silicate electrode for lithium-ion batteries

Highlights: • ZnO-coated Li₂MnSiO₄/C cathode materials have been successfully prepared via sol–gel method for the first time. • The electrochemical performance of the pure Li₂MnSiO₄/C has been significantly improved after coating 1 wt% ZnO. • The better electrochemical performance can be attributed to the improvement of electrochemical kinetics by coating ZnO. - Abstract: ZnO-coated Li₂MnSiO₄/C composites have been successfully prepared by a preliminary formation of Li₂MnSiO₄/C by facile sol–gel method and a following coating process with ZnO via a wet chemical process. Phase compositions and morphology of the products have been investigated by XRD, SEM, TEM and EDX. The physical characterizations manifest that nano-layer ZnO has been successfully coated on the Li₂MnSiO₄ particle surface. Among the samples, 1 wt% ZnO coated Li₂MnSiO₄/C shows the best performance with an initial discharge capacity of 183 mAh g⁻¹ at 0.1C rate and the specific capacities of 142 and 134 mAh g⁻¹ at the high rate of 0.5C and 1C, respectively, which is much better than Li₂MnSiO₄/C without coating ZnO. The better electrochemical performance can be attributed to the significantly decrease of the charge transfer resistance and improvement of lithium ion diffusion coefficient after coating ZnO, which is beneficial for the rapid insertion/extraction of lithium ions