Nitrogen‐Doped Graphitic Carbon‐CoTe2 Decorated on Carbon Aerogel Microspheres as a High‐Rate and Ultra‐Stable Electrode for Efficient Capacitive Storage

Abstract Nitrogen‐doped graphitic carbon‐CoTe 2 decorated on carbon aerogel microspheres (NG‐CoTe 2 /CRF) are designed and synthesized through a scalable co‐precipitation reaction combined with a high‐temperature tellurization process. The porous and large surface‐specific CRF microspheres inhibited the further growth of CoTe 2 nanoparticles, resulting in smaller dimensional NG‐CoTe 2 /CRF composites were achieved. The obtained NG‐CoTe 2 /CRF composites (smaller size particles and larger pore sizes) provide more active sites for electrochemical reactions and accelerate the transport of electrolyte ions, thereby promoting the capacitive contribution of the fast redox reaction, the capacitive contribution can even reach 93% at a scan rate of 8 mV s −1 . The novel electrode material also possesses excellently ultra‐stable and high‐rate performance. Moreover, the assembled NG‐CoTe 2 /CRF//activated carbon (AC) asymmetric supercapacitor presents satisfactory electrochemical performance, delivering a high energy density of 49.8 W h kg −1 at a power density of 985 W kg −1 and competitive cyclic stability (125.2% retention of initial capacity after 5000 cycles). This work designs an effective synthetic route and validates the potential prospects of carbon aerogels tuning the structure of transition metal tellurides for developing high‐performance and advanced energy storage devices. This strategy can be extended to the fields of battery and electrocatalysis.