Novel Electrode Materials and Redox‐Active Electrolyte for High‐Performance Supercapacitor

Abstract

Heteroatom doping has been increasingly applied to enhance the electrochemical performance of carbon materials when used as supercapacitor electrodes. However, the use of doped electrode by itself often does not provide sufficiently high performance for aqueous-based supercapacitor. Here, a highperformance supercapacitor was developed, using nitrogendoped microporous carbon spheres-based materials and a redox-active electrolyte as electrodes and electrolyte, respectively. The doped electrode, which was produced via template and self-assembly routes, exhibited a well-developed microporous structure, large specific surface area, and abundant heteroatoms. The combination of the heteroatom-doped electrode and KI-H 2 SO 4 electrolyte in supercapacitor substantially increased the specific capacitance, from 230 F g À 1 to 532 mAh g À 1 . Such a large enhancement was attributed to the addition of KI as a redox mediator in the aqueous electrolyte. The NCS-800 supercapacitor has a specific capacity as high as 68 mAh g À 1 (at a 1 A g À 1 current density) in KI-H 2 SO 4 electrolyte. It could retain 57 % of capacitance even after maintaining a constant voltage of 1 V for 5 hours, highlighting its good electrochemical performance of NCS-800 as a supercapacitor electrode material.

Self-Supporting Lignin-Based Carbon Material Flexible Supercapacitor Prepared by the Microwave Method

“…Two and three sp2 carbon atoms bond to N-6 and N-Q, which can contribute one or two electrons to the π system and improve the conductivity of carbon materials. 31 N-5 can produce a great pseudocapacitance effect, which helps improve the capacitance performance of carbon materials. From Figure 3d shape.…”

“…The presence of N-5 in sample D2 can enhance the anchor point of CO 2 capture, which indicates its good adsorption performance. Two and three sp2 carbon atoms bond to N-6 and N-Q, which can contribute one or two electrons to the π system and improve the conductivity of carbon materials . N-5 can produce a great pseudocapacitance effect, which helps improve the capacitance performance of carbon materials.…”

Cobalt‐Nickel Ultrathin Hexagonal Nanosheets for High‐performance Asymmetric Supercapacitors

“…Energy storage technology has attracted considerable attentions in achieving carbon peaks and carbon neutrality [2–3] . Supercapacitors (SCs) have considerably high power density, rapid charge/discharge ability and long cycle life, being widely studied as promising energy storage devices [4–6] . However, the energy density of SCs is relatively low, which limits their development and wide‐scale practical applications [7–8] .…”

“…[2][3] Supercapacitors (SCs) have considerably high power density, rapid charge/discharge ability and long cycle life, being widely studied as promising energy storage devices. [4][5][6] However, the energy density of SCs is relatively low, which limits their development and wide-scale practical applications. [7][8] To improve this issue, many researchers have devoted considerable efforts to design innovative electrode materials with good electrochemical performance.…”

Enhancing supercapacitor performance using nanosheet-covered nanotube structures Co3S4/Ni0.96S@CNTs with carbon nanotubes as conductive substrates

“…2 Supercapacitors (SCs) are important new energy storage elements, and their development is inseparable from efficient and ideal energy storage materials. [3][4][5] The electronegativity of sulfur is low; therefore, the structure of metal sulfides is easy to control. Furthermore, they exhibit a low rate of expansion and strong mechanical stability and can effectively transfer charge for a long period, particularly nickel and cobalt-based sulfides.…”