Porous Carbon Framework with B-Doped NiCo2O4 Nanoclusters for Enhancing the Performance of Carbon Fiber-Based Flexible Supercapacitors

Adequate atomic doping and multidimensional nanostructure construction are two important means to improve the performance of supercapacitors. Herein, we proposed a simple method to produce high-performance fiber-based electrodes by integrating B-doped NiCo2O4 nanoclusters (B–NCO) with a B, N codoped porous carbon framework (BNC). A 3D porous structure enabled a continuous conductive path and charge storage space, while the doping of B and N atoms increased additional active sites and hydrophilicity. Therefore, BNC can not only provide good interface conditions for B–NCO growth to reduce contact resistance but also be applied as a negative electrode with excellent performance. Notably, the formation of the tip effect can enrich a large number of electrons at the tip of NCO nanoclusters, forming a local electrostatic field and effectively improving the utilization of electrons. The different doping forms of the B atoms provide NCO with higher conductivity and more active sites. Leveraging these attributes, the B–NCO@BNC/CF electrode exhibited excellent mass-specific capacitance of up to 2015.8 F g–1 at a current density of 0.5 A g–1. The resulting B–NCO@BNC/CF//BNC/CF achieved a high energy output of 86.7 Wh kg–1 and long-term durability. This work proposes a low-cost and effective way to fabricate hierarchically structured electrodes for wearable supercapacitors.