Design and construction of multiwall carbon nanotube wrapped Co(OH)2 nanobricks: A high-performance supercapacitor for energy storage applications

The issue of inadequate conductivity of electrons is consistently linked to the electrode material for pseudocapacitor , which hinders the complete utilization of the active material. In order to address this issue effectively, we have developed a composite material consisting of carbon nanotubes (CNTs) that are extremely conductive and wrapped around pseudocapacitive Co(OH) 2 nanobricks. The supercapacitor is created in our laboratory using a modified hydrothermal method (MHT) that allows for in situ growth. An electrochemical study confirms that the Co(OH) 2 @MWCNT electrode is extremely reactive, resulting in a maximum specific capacitance of 1911 Fg −1 (at 1 Ag −1 ). Furthermore, after 10,000 cycles of execution, it displays remarkable stability over the long term, with 96.5 % retention at a constant current density of 1 Ag −1 . In addition, the ASC has a significant energy density of 89.3 Whkg −1 at 1 Ag −1 . Furthermore, the device maintains an excellent energy density of 55.5 Whkg −1 while operating at a power density of 1015 Wkg −1 . In addition, the Co(OH) 2 @CNT//AC ASC has remarkable long-term cycling stability, with a just 4 % decrease in capacitance after 10,000 cycles. Furthermore, the device continues to maintain a commendable Coulombic efficiency of 83.5 %. These promising results indicate that these materials have the potential to be used in economical and reliable energy storage technologies .