Review—Clay Mineral Materials for Electrochemical Capacitance Application

Electrochemical capacitors, also called supercapacitors (SCs), play an important role in the field of electrochemical energy storage and have great potential to become the most advanced power supply for portable electronic devices and electric vehicles. The performance of SCs depends mainly on the properties of the electrode material, and many novel electrode materials have been explored. Clay mineral materials, including montmorillonite, halloysite, and attapulgite, are potential electrode materials due to their layered structure, high specific surface area, natural abundance, low cost, and environmentally friendly nature. However, most of them suffer from low electronic conductivity, which limits their application as high-performance electrodes for SCs. Many efforts have been made to resolve this issue. Here, we summarize a series of clay mineral based electrode materials for SCs. To better develop clay minerals to produce green and pollution-free electrode materials, the structures and properties of minerals are also introduced. In addition, the challenges and prospects of clay mineral materials are also blueprinted.