Effect of carbon shell over NaCrO2 core by C2H2 decomposition to enhance electrochemical properties for rechargeable Sodium-ion batteries

[Display omitted] •Preparation of NaCrO2 nanoparticles using solid state synthesis method.•Pyrolysis of Acetylene gas on NaCrO2 leads to carbon on surface as core – shell like nanoparticles.•Raman analysis indicate amorphous nature of carbon deposit as core–shell.•Deposition of carbon over NaCrO2 resulted in enhanced electrochemical properties. In this study, carbon shell was synthesized over the surface of NaCrO2using chemical vapor decompositionto make it apotential cathode material for sodium-ion batteries. Carbon deposition has been attempted by the decomposition of C2H2gas at elevated temperature to enhance the electrochemical performance of pristineNaCrO2.Hence, a series of samples were synthesized by varying the time of exposure of C2H2over the surface of NaCrO2. The XRD data revealsthe proper phase formation of pristine NaCrO2and NaCrO2/C. FESEM and HRTEM indicate the presence of carbon shell over the NaCrO2,making it a core–shell structure. Raman analysis has been performed to see the crystallinity of the deposited carbon on the surface of NaCrO2. Moreover, Thermogravimetric analysis has been carried to calculate the amount of carbon deposition with the variation of exposure time. The electrochemical performance of pristine and exposed NaCrO2are also studied. It reveals the highest specific capacity of 126.5 mAhg−1 at 0.5C. The highest capacity retention of about 89 % has been observed for optimized carbon deposited sample after 40 cycles at 1C rate. These results are helpful to understand the role of carbon deposition as a conductive additive on electrochemical properties.