Supercapacitor performance and charge storage mechanism of brannerite type CuV2O6/PANI nanocomposites synthesis with their theoretical aspects

In the present study, for the first time, we report a simple, low-temperature co-precipitation followed by in-situ polymerization method for synthesis of brannerite type copper vanadate (CuV2O6) layered nanosheets modified (in-situ) with polyaniline (PANI) conducting polymer for enhanced supercapacitor performance. A density functional theory (DFT) calculation suggests that a strong interaction between CuV(2)O(6 & nbsp;)and PANI (through the transfer of charge from N of PANI to O of CuV2O6) is the major reason for the enhanced charge-storage activity of the crafted electrodes. Besides, the effect of Cu to V precursor concentration ratio towards the charge storage capacitance of the crafted materials was studied. Among the studied compositions viz. 1:1, 1:2, and 2:1, only the ratio of 1:1 was noted to show CuV(2)O(6 & nbsp;)and the highest charge storage capacity. Moreover, the charge storage mechanism of CuV2O6 & nbsp;nanosheets based supercapacitor device especially towards contribution of electrical double layer and pseudo-capacitive charging has been investigated. The presence of PANI is noted to show dramatic improvement in the charge-storage capacity of the resulting supercapacitor electrodes, exhibiting specific capacitance of 375 F g(-1) at a current density of 4 A g(-1). Also, the symmetric full-cell supercapacitor device is fabricated by controlling loading mass of the electrode materials. It shows a specific capacitance of 8 F g(-1)& nbsp;at a current density of 0.2 A g(-1)& nbsp;along with a maximum energy density of 1.6 Wh kg(-1)& nbsp;at a power density of 480 W kg(-1). It also exhibits excellent cycle stability with a capacitance retention of 98% after 2000 cycles, and 77% after 5000 cycles.

Automated summary

This study presents a novel method for enhancing the performance of supercapacitors through the synthesis of CuV2O6 nanosheets modified with PANI conducting polymer. The interaction between CuV2O6 and PANI plays a key role in improving the charge-storage activity of the electrodes. The presence of PANI significantly increases the charge-storage capacity of the resulting supercapacitor electrodes.