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N-doped hierarchical porous carbon as an excellent electrode material in symmetric supercapacitor is fabricated by a facile and green method. [Display omitted] • N-doped porous carbon is prepared from one-step pyrolysis of glycine and Na 2 CO 3. • It exhibits a high capacitance of 207 F/g at 20 A/g in a symmetric supercapacitor. • 99.95% of initial capacitance remains after 10,000 cycles at 5 A/g. • A high energy density of 28.8 Wh/kg is obtained at a power density of 20 KW/kg. N-doped hierarchical porous carbon (NHPC) was facilely fabricated by a one-step pyrolysis of glycine and water-soluble Na 2 CO 3 , which is employed as a renewable water-soluble template without additional corrosive activating reagent. Benefiting from the hierarchical porous structure, high specific surface area (2735 m2 g−1) and the suitable nitrogen content of 3.84 at%, the obtained porous carbon exhibits a high specific capacitance (C sp) of 267 F g−1 at 0.2 A g−1 in a three-electrode system and 201 F g−1 at 0.2 A g−1 in the symmetric supercapacitor. More importantly, it shows an impressive rate capability of 102 % retention at 20 A g−1, outstanding cycling stability with 99.95 % of capacitance retention at 5 A g−1 after 10,000 cycles and a high energy density of 28.8 Wh kg−1 at a power density of 20 KW kg−1 in the symmetric supercapacitor. The results indicate that the synthesized NHPC obtained from this simple synthesis method would be an effective electrode material for symmetric supercapacitors, and this eco-friendly and easily scaled-up approach would provide a valuable strategy for the synthesis of porous carbon materials. [ABSTRACT FROM AUTHOR]

• Tubular Cu 2 MoS 4 /MWCNTs were prepared as supercapacitor negative electrode material. • Appropriate MWCNTs addition significantly optimized the electrochemical performance. • CMS/MWCNTs-0.15@CC exhibits a highest specific capacitance of 219F g−1 at 0.5 A g−1. • The device with a voltage window of 1.8 V yields an energy density of 24.5 Wh kg−1 at 900 W kg−1. The ternary layered Cu 2 MoS 4 (CMS) has been proven to be a potential supercapacitor negative electrode material. However, its inherent low conductivity and limited diffusion dynamics usually result in unsatisfactory specific capacitance and rate performance. Therefore, hollow tubular CMS and CMS/MWCNTs-0.05, 0.15, 0.25 composite materials were prepared by a one-pot hydrothermal method in this work. The addition of MWCNTs improves the electrical conductivity and provides an efficient three-dimensional electronic transport network. Due to the smallest resistance and optimized porous structure with large surface area, CMS/MWCNTs-0.15@CC exhibits a highest specific capacitance (C s) of 219F g−1 at 0.5 A g−1, which is 2.45 times that of CMS@CC. The assembled Ni-Co-S@CC//CMS/MWCNTs-0.15@CC supercapacitor with a voltage window of 1.8 V yields a maximum energy density of 24.5 Wh kg−1 at 900 W kg−1. [ABSTRACT FROM AUTHOR]