A comprehensive review on transition metal nitrides electrode materials for supercapacitor: Syntheses, electronic structure engineering, present perspectives and future aspects

The creation of innovative materials that enhance energy storage efficiency is crucial for sustainable societal development and meeting the world's growing energy demand. In this context, both energy storage devices and the materials utilized play significant roles. Among various energy storage devices, supercapacitors (SCs) are gaining popularity as highly attractive complementary devices. They offer advantages such as fast charge-discharge capabilities, high specific capacitance (Cs), reversibility, and long lifespan. Transition metal nitrides (TMNs) constitute a unique class of materials that have garnered attention for their substantial redox activity, exceptional thermal and chemical stability, improved electron and ion conductivity, low cost, and high volumetric energy density. These attributes make TMNs an attractive choice for integration into SCs and rechargeable battery devices. Recent research has focused on the development of TMNs and TMNs-based composites for high-performance SC devices. This concept aims to provide an overview of the recent progress of TMNs in SC applications. The discussion encompasses various preparation techniques for various types of TMNs and their modification strategies, such as conducting polymer hybrids-based TMNs, heterostructure metal nitride, doped metal nitride, and multi-metal nitride, which have shown potential in enhancing the electrochemical performance of SCs. Additionally, an overview of the structural stability of TMN electrodes after electrochemical studies is provided. Finally, the challenges and future perspectives of TMNs in SCs are covered, offering valuable insights for the development of next-generation energy storage devices based on TMNs.