MnO2 modified perovskite oxide SrCo0.875Nb0.125O3 as supercapacitor electrode material

Cobalt-based perovskite SrCo 0.875 Nb 0.125 O 3 is an advantageous electrode material for supercapacitors . However, the particle form of SrCo 0.875 Nb 0.125 O 3 is not conducive to the electrochemical behavior. Based on this, surface MnO 2 modified SrCo 0.875 Nb 0.125 O 3 on carbon cloth (MnO 2 @SrCo 0.875 Nb 0.125 O 3 @CC) has been prepared as supercapacitor electrode. The dandelion-like morphology of MnO 2 significantly increases the specific surface area and inhibits the grain agglomeration of SrCo 0.875 Nb 0.125 O 3 , thus promoting the ion diffusion during the electrochemical process. As a result, the electrochemical performance of the composite is significantly optimized due to the synergistic effect of SrCo 0.875 Nb 0.125 O 3 and MnO 2 . The MnO 2 @SrCo 0.875 Nb 0.125 O 3 @CC electrode yields an ultra-high specific capacitance of 2066.0 mF cm −2 at 2 mA cm −2 current density. Compared with SrCo 0.875 Nb 0.125 O 3 @CC electrode and MnO 2 @CC electrode, this work provides a much improved performance. Besides, an asymmetric supercapacitor composed of MnO 2 @ SrCo 0.875 Nb 0.125 O 3 @CC as positive electrode and CuS@CC as negative electrode exhibits a voltage window of 1.8 V and a specific capacitance of 114.6 mF cm −2 when the current density is 3 mA cm −2 . A high energy density of 51.57  μ $\mathrm{\mu }$ Wh cm −2 is achieved at a power density of 4.86 mW cm −2 for the device.