All‐Solid‐State Supercapacitors Based on Cobalt Magnesium Telluride Microtubes Decorated with Tellurium Nanotubes

Abstract

AbstractMagnesium (Mg) has received very little exploration on its importance in the realm of battery‐type energy storage technologies. They are abundantly present in seawater, and if successfully extracted and utilized in energy storage systems, it could lead to the long‐term advancement of human civilization. Here, we fabricated an all‐solid‐state supercapacitor (ASSSC) using tellurium nanotubes decorated cobalt magnesium telluride microtubes (Te NTs@CoMgTe MTs) clad on nickel foam (NF). Owing to the unique mixed phase hierarchical structure, Te NTs@CoMgTe MTs showcases some advancement in energy storage performance. When tested in a three‐electrode system, multiphasic hybrid of elemental Te and metal tellurides, Te NTs@CoMgTe MTs outperforms the monometallic telluride owing to the strong synergistic interaction effect triggered from conductive three components and delivers a long‐life span performance up to 15,000 cycles. The fabricated Te NT@CoMgTe MT//AC solid‐state device exhibits a maximum areal capacity of 59.2 μAh cm−2 (56.3 mAh g−1) at a current density of 6 mA cm−2 with a maximum energy density of 42.2 Wh kg−1 (46.5 μWh cm−2) at a power density of 6857.1 W kg−1 (7574.6 μW cm−2). The performance of the device is rigid even at different bending angles (0 to 180°) which validates the extensibility of the process for future applications.