N-doped carbon foam based three-dimensional electrode architectures and asymmetric supercapacitors

Abstract

Improving the electrochemical performance of supercapacitors mainly depends on the electrode design and system construction. A new kind of additive-free asymmetric supercapacitors (ASCs) has been successfully fabricated using a self-supported carbon foam/ordered mesoporous carbon (CF-OMC) film as the negative electrode and free-standing CF-NiCo₂O₄ nanosheets (NSs) as the positive electrode, respectively. The highly conductive three-dimensional (3D) CF framework could facilitate electron transfer while the porous thin film of OMC and ultrathin NiCo₂O₄ nanosheets could shorten the ion diffusion path and facilitate the rapid migration of electrolyte ions. The optimized asymmetric supercapacitors could work with an operational voltage of 1.6 V, delivering a high energy density (∼47.8 W h kg⁻¹), high power density (∼9800 W kg⁻¹ at 17.7 W h kg⁻¹) and outstanding cycle stability (∼10 000 times). This research may pave the way for fabricating lightweight, low-cost, and high-performance electrodes for energy storage applications.