N-doped carbon coating for stabilizing metal sulfides on carbon materials for high cycle life asymmetric supercapacitors

Manufacturing hybrid electrodes with the combination of electroactive materials and carbon carriers brings hope for high-performance supercapacitors, but the poor interfacial compatibility between hydrophobic carbon substrate surface and active materials is still the bottleneck to be solved. Here, we propose a superhydrophilic strategy to stabilize NiCo2S4 on inert carbon cloth (CC) using nitrogen-doped (N-doped) carbon layer as structure/interface coupling bridge, so as to prepare hybrid material (expressed as NiCo2S4/CC-CN) for supercapacitor. The N-doped carbon layer on CC leads to the formation of superhydrophilic surface/interface, which is conducive to the uniform growth of NiCo2S4 on CC and helps to effectively strong coupling interaction between CC and NiCo2S4. In addition, the asymmetric supercapacitor made of NiCo2S4/CC-CN as the positive electrode and as-prepared activated carbon cloth (PACC) as the negative electrode provides a high energy density of 0.11 mWh cm(-2) at a power density of 0.35 mW cm(-2). The interfacial engineering in this study holds the potential of creating high energy density electrodes for advanced energy storage.

Automated summary

This study proposes a superhydrophilic strategy to stabilize NiCo2S4 on inert carbon cloth through a nitrogen-doped carbon layer, successfully preparing a hybrid material for supercapacitors. The formation of a hydrophilic surface/interface facilitates uniform growth of the material and enables effective coupling interaction, resulting in a high energy density in asymmetric supercapacitors.