Waste Coffee Management: Deriving High-Performance Supercapacitors Using Nitrogen-Doped Coffee-Derived Carbon

Abstract

In this work, nitrogen-doped activated carbon was produced from waste coffee powder using a two-step chemical activation process. Nitrogen doping was achieved by treating the coffee powder with melamine, prior to chemical activation. The produced nitrogen-doped carbon resulted in a very high surface area of 1824 m2/g and maintained a high graphitic phase as confirmed by Raman spectroscopy. The elemental composition of the obtained coffee-derived carbon was analyzed using X-ray photoelectron spectroscopy (XPS). The supercapacitor electrodes were fabricated using coffee-waste-derived carbon and analyzed using a three-electrode cell testing system. It was observed that nitrogen-doping improved the electrochemical performance of the carbon and therefore the charge storage capacity. The nitrogen-doped coffee carbon showed a high specific capacitance of 148 F/g at a current density of 0.5 A/g. The symmetrical coin cell device was fabricated using coffee-derived carbon electrodes to analyze its real-time performance. The device showed the highest specific capacitance of 74 F/g at a current density of 1 A/g. The highest energy and power density for the device was calculated to be 12.8 and 6.64 kW/kg, respectively. The stability test of the device resulted in capacitance retention of 97% after 10,000 cycles while maintaining its coulombic efficiency of 100%. These results indicate that the synthesized nitrogen-doped coffee carbon electrode could be used as a high-performance supercapacitor electrode for energy storage applications, and at the same time manage the waste generated by using coffee.

Electrochemical Performance of Titania 3D Nanonetwork Electrodes Induced by Pulse Ionization at Varied Pulse Repetitions

“…The results for C sp at different scan rates, from 20 to 500 mV/s, have been presented in Figure 4 c. The results show that the specific capacitance decreases by increasing the scan rate from 20 to 500 mV/s which can be due to different factors such as pore-size distribution, the presence both of micro- and mesopores, and specific surface area as reported before [ 33 , 34 , 35 , 36 ]. In both S2 and S3, charged nanofibrous structures have more time at lower scan rates to interact with other fibers and pores of T3DN electrodes.…”

Thermal treatment versus hydrothermal carbonization: How to synthesize nitrogen‐enriched carbon materials for energy storage applications?

“…Choi et al, reversed the last two steps in the method proposed by Pietrzak et al, and prepared NCM from spent coffee grounds (SCG) and melamine using the following method: pyrolysis (800°C for 2 hours) → reaction with melamine (800°C for 2 hours) → KOH activation (800°C for 2 hours). The XPS results showed that the N was incorporated to the surface of the NCM; moreover, after KOH activation, a significant reduction in the N content occurred, and most of the pyridinic‐N and graphitic‐N vanished 18 …”

Nanoarchitectonics of Nanoporous Carbon Materials in Supercapacitors Applications

“…The Sichuan pepper-derived carbon material display reasonably good electrochemical performance with specific capacitance 171 F g −1 at 1 A g −1 without any capacitance loss until 10,000 charging−discharging cycles. KOH activation of coffee powder (waste material) interestingly yielded nitrogen-doped carbon as reported by Gupta and coworkers [148]. For the successful nitrogen doping coffee powder required to treat with melamine prior to the activation.…”