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.