Carboxymethylcellulose ammonium-derived nitrogen-doped carbon fiber/molybdenum disulfide hybrids for high-performance supercapacitor electrodes

In this paper, a new type of nitrogen-doped carbon fiber/molybdenum disulfide (N-CFs/MoS₂) hybrid electrode materials are prepared <i>via</i> a certain concentration in solvothermal synthesis followed by a high-temperature carbonization process and using the carboxymethylcellulose ammonium (CMC-NH₄) as a structure-directing agent for MoS₂ nanosheet growth during the solvothermal synthesis process. The addition of CMC-NH₄ effectively prevents the agglomeration of MoS₂ nanosheets to increase the specific surface area. Moreover, it not only serves as a carbon source to provide conductive pathways, but also introduces N atoms to improve the conductivity of the CFs and promote the transfer of electrons and ions. This ultimately increases the conductivity of the electrode materials. Thus, the as-prepared N-CFs/MoS₂ hybrids exhibit excellent electrochemical performance. The specific capacitance is up to 572.6 F g^-1 under a current density of 0.75 A g^-1 and the specific capacitance retained 98% of the initial capacitance after 5000 cycles of charge-discharge tests at a current density of 2.5 A g^-1. Moreover, the hybrids show a maximum energy density of 19.5 W h kg^-1 at a power density of 94 W kg^-1. Therefore, the as-prepared N-CFs/MoS₂ hybrids with remarkable electrochemical properties, low cost and environment protection show potential for practical application in the development of high-performance electrochemical energy storage devices.