Chromium Oxynitride as Durable Electrode Material for Symmetric Supercapacitors

Abstract

AbstractRecently, metal oxynitrides (MONs) have gained a lot of attention as electrode materials for supercapacitor (SC) applications due to their unique properties such as high electronic conductivity, wettability, corrosion resistance, and chemical robustness. Nanostructuring strategies of MONs opens fresh avenues for energy storage. Though various transition metal oxides (MO) and metal nitrides (MN) have been explored as electrode materials for SC applications, they have limitations associated with poor cyclability and rate capabilities. Hence, there is a value to exploring intermediate oxynitride compounds (MONs) in place of pure MOs and MNs. Chromium oxynitride (CrOXNY) as electrode material is not yet been explored for SC applications. In this context, we have carried out the systematic study of the nanostructured nano‐spherical CrOXNY nanoparticle as an electrode material for SC applications. The electrochemical performance of the CrOXNY electrode is tested in both the three and two electrode assembly. The CrOXNY electrode shows capacitance of 146 F g−1 at 10 mV s−1 in three electrode configuration. The symmetric coin cell (CR2032) is fabricated and tested up to 10,000 cycles at 2 A g−1 and it shows excellent capacity retention up to 98 %. The energy and power densities of the symmetric device are ∼8 W h kg−1 at 1 A g−1 and 28.8 kW kg−1 at 10 A g−1, respectively. As a proof of concept, a red light‐emitting diode (LED) is lit by serially connecting two symmetric coin cells (2 V). These attributes of CrOXNY, such as excellent capacitance retention, long cyclic stability, and high rate capability, indicates that it can be used as a durable electrode material for SC technology.