One-step hydrothermal synthesis of sulfur-doped Ni2(OH)2CO3 neuroid network combined with multi-walled carbon nanotubes for high-performance asymmetric supercapacitors

In this reported work, S-Ni2(OH)2CO3@MWCNTs nanocomposites were prepared using a one-step hydrothermal method. Among them, S atoms are doped into Ni2(OH)2CO3 without replacing OH−, and there is electronic interaction between Ni2(OH)2CO3 and S atoms or MWCNTs. Finally, four materials with similar morphologies were prepared to establish a system model to determine how S doping affects the electrochemical performance of the host material. The experimental results show that S doping can improve the electrochemical performance of S-Ni2(OH)2CO3@MWCNTs. The asymmetric supercapacitors is assembled using S-Ni2(OH)2CO3@MWCNTs and activated carbon, with an energy density of 45 Wh kg−1 and excellent long-term cycle stability. This research provides a new strategy for improving the electrochemical performance of supercapacitor electrode materials. [Display omitted] •S-Ni2(OH)2CO3@MWCNTs nanocomposites were prepared using a one-step hydrothermal method.•XRD analysis shows that S atoms are doped into Ni2(OH)2CO3 without replacing OH−.•XPS analysis shows that there was an electronic interaction between the Ni2(OH)2CO3 and the S atoms or the MWCNTs.•The ASC assembled by S-Ni2(OH)2CO3@MWCNTs and AC has high energy density and excellent cycle stability.