N/O Co-doped Porous Carbons Derived from Coal Tar Pitch for Ultra-high Specific Capacitance Supercapacitors

Abstract

In this paper, a series of N/O co-doped porous carbons (PCs) were designed and used to prepare coal tar pitch-based supercapacitors (SCs). The introduction of N/O species under the intervention of urea effectively improves the pseudocapacitance of PCs. The results show that the specific surface area of synthesized N 3 PC 4-700 is 1914 m 2 g –1 , while the N and O contents are 1.3 and 7.2%, respectively. The unique interconnected pore structure and proper organic N/O co-doping, especially the introduction of pyridine-N and pyrrole-N, are beneficial for improving the electrochemical performance of PCs. In the three-electrode system, the specific capacitance and rate capability of N 3 PC 4-700 are 532.5 F g –1 and 72.5% at the current densities of 0.5 and 20 A g –1 , respectively. In addition, the specific capacitance of N 3 PC 4-700 in a coin-type symmetric device is 315.5 F g –1 at 0.5 A g –1 . The N 3 PC 4-700 electrode provides an energy density of 43.8 W h kg –1 with a power density of 0.5 kW kg –1 and still maintains a value of 29.7 at 10 kW kg –1 . After 10,000 charge/discharge cycles, the retention rate was as high as 96.7%. In order to obtain high-performance carbon-based SCs, the effective identification and regulation of organic N/O species is necessary.

One‐Step Preparation Pitch‐Based Porous Carbon via Carbonization and Co‐Activation for High‐Performance Supercapacitors

“…The good shape between the high frequency region also signifies a small Rct and Rc. The Ragone plot of the assembled MPPC‐4 SC is depicted by Figure 6f, which can reach a prominent energy density of 29.83 Wh kg −1 at a power density of 999.93 W kg −1 , when the power density attains 19.89 kW kg −1 , it can still maintain 6.56 Wh kg −1 , showing better performance than the previously reported pitch‐based porous carbon SCs [10,33,45,48,56,60–64] . Furthermore, the assembled MPPC‐4 symmetric SC was cycled for 5000 times at 5 A g −1 , manifesting remarkable cycling stability (Figure 6g).…”

Salt-assisted synthesis of advanced carbon-based materials for energy-related applications

“…Heteroatom doping is demonstrated to be a versatile option to adjust the electronic and chemical character and increase available active sites in carbons, leading to an enhanced electrochemical performance of carbon materials. 72–76 Wu et al reported the synthesis of N,O co-doped porous carbons by pyrolysis of macadamia nut shells and melamine in potassium chloride (KCl). They found that KCl can be applied as a flame retardant, allowing pyrolysis in the gas stream.…”

Coal Tar Pitch-Based Porous Carbon Loaded MoS2 and Its Application in Supercapacitors

“…The production capacity of medium- and low-temperature coal tar asphalt in Yulin is about 3.68 million tons, accounting for 60% of the national production capacity. However, medium- and low-temperature coal tar pitch is mostly used as infrastructure materials and heavy fuel oil, resulting in serious waste of carbon resources and environmental pollution . Therefore, how to improve the utilization of high-value-added products based on coal tar pitch has become an urgent problem to be solved.…”