Metal‐Organic Frameworks‐Derived NiS₂/CoS₂/N‐Doped Carbon Composites as Electrode Materials for Asymmetric Supercapacitor

Abstract

Transition metal sulfides derived from metal-organic frameworks (MOFs) have received increasing attention as a potential energy storage electrode material. Here, a series of NiS 2 /CoS 2 / NC-T (T = temperature) have been successfully constructed by carbonizing and sulfuring the precursor of Ni/Co-MOF. It is worth emphasizing that N-doped carbon materials improve the conductivity of the electrode material. Moreover, NiS 2 /CoS 2 /NC-500 maintains the rod-like structure of the precursor and exhibits a high specific capacitance of 1325 F g À 1 at a current density of 1 A g À 1 . Apart from high capacitance, the NiS 2 /CoS 2 / NC-500 also demonstrated excellent cycling stability with retention rate of 75 % after 5000 cycles at a current density of 5 A g À 1 . The good performance could be attributed to the unique rod-like structure and pore-size distribution of NiS 2 / CoS 2 /NC-500. Moreover, an assembled asymmetric supercapacitor NiS 2 /CoS 2 /NC-500//AC displays a high energy density of 53.93 Wh kg À 1 at a power density of 800 W kg À 1 and good cycle stability with capacitance retention of 85.71 % after 20,000 cycles at 5 A g À 1 . In particular, a red LED can be illuminated by the assembled ASC, indicating that as-synthesized NiS 2 /CoS 2 / NC-500 hold great potential for practical applications.

Biomass-Derived Porous Carbon-Anchoring MnFe2O4 Hollow Sphere and Needle-Like NiS for a Flexible All-Solid-State Asymmetric Supercapacitor

“…Moreover, Figure a shows the digital image of the flexible supercapacitor and three ASC devices connected in series, and Figure b shows the glowing of a panel (NNG) consisting of light-emitting diodes (LEDs) for 60 s with astonishing intensity, displaying the profound performance of the device for practical applicability in energy storage applications. Figure c–f shows the digital image at varying bending angles, demonstrating the remarkable flexibility of the device. − …”

Zeolitic imidazolate framework (ZIF)-derived porous carbon materials for supercapacitors: an overview

“…112 Compared with nickel oxides, nickel suldes oen have better structural stability and faster electron transfer, which is ascribed to the lesser electronegativity value of sulfur in comparison to oxygen. 113,114 The replacement of O 2À by S 2À in MOF-derived Ni oxides can effectively improve its conductivity and electrochemical activity.…”

Lignin‐derived carbon nanofibers‐laminated redox‐active ‐mixed metal sulfides for high‐energy rechargeable hybrid supercapacitors

“…The energy and power densities of the AC//LCNFs@NiMnS‐1 HSC are thus superior to other previously reported metal‐sulfide‐based HSCs (Table S1). The HSC device outperforms many recently reported symmetric and asymmetric supercapacitors, such as ECNFs@NiMnO//ECNFs@NiMnO (20.4 W h kg −1 ; 700.0 W kg −1 ), 25 Ni‐Mn sulfide//rGO (36 W h kg −1 ; 775 W kg −1 ), 26 CoMnS//rGO (22.3 W h kg −1 ; 750 W kg −1 ), 28 Ni‐Co‐Mn sulfide//AC (49.8 W h kg −1 ; 1700 W kg −1 ), 30 Co 3 O 4 @Ni(OH) 2 //AC (49.8 W h kg −1 ; 801 W kg −1 ), 47 NiS 2 //rGO (32.76 W h kg −1 ; 954 W kg −1 ), 48 MnS‐N‐rGO//N‐rGO (27.7 W h kg −1 ; 800 W kg −1 ), 49 Ni‐Co sulfide//AC‐ASC (24.8 W h kg −1 ; 849.5 W kg −1 ), 50 CoNi‐layered double hydroxides//AC (20.38 W h kg −1 ; 800 W kg −1 ), 51 Co‐doped Ni 0.75 Co 0.25 S 2 //AC (54.7 W h kg −1 ; 1515 W kg −1 ), 52 rGO‐MNCO//rGO (35.6 W h kg −1 ; 699.9 W kg −1 ), 53 NiS 2 /CoS 2 ‐NC//AC (53.9 W h kg −1 ; 800 W kg −1 ), 54 and NiHpi‐500//AC (50 W h kg −1 ; 362 W kg −1 ) 55 . In addition, the directly sulfidated AC//LCNFs@NiMnS‐1 hybrid provided a higher energy density as compared with the postsulfidated Ni‐Mn sulfide and similar Ni‐Mn‐S based electrode materials at similar power densities (Figure 5G).…”