Similarities and differences between tannin- and resorcinol-based carbon aerogels: nitrogen-doping, electrical conductivity, and performance in a Zn-based electrochemical cell

Abstract Carbon aerogels derived from organic precursors are gaining attention in various applications, especially in energy storage. On one hand, this paper deals with the substitution of phenolic materials by tannin which could be beneficial to both the bioeconomy and the environment due to its low-cost, bio-based, and non-toxic characteristics. On the other hand, the comparative study aims to explore advantages and drawbacks of both aerogels, their electrical conductivity, morphology, performance in an electrochemical cell, and materials costs. The results illustrate that both nitrogen-doped aerogels exhibit pyridinic and pyrrolic functional groups, while doping with melamine leads to higher nitrogen amount about 5 wt.-% compared against ammonia treatment (1–2.5 wt.-%). RF-based carbon aerogels exhibit almost twice the electrical conductivity of tannin-based carbon aerogels. The electrochemical performance of both carbon aerogels in an electrochemical cell is comparable to literature-reported cases. The capacitance of non-doped aerogels was found to be the highest, reaching 239 F‧g –1 at a current density of 0.5 A g –1 . Material costs of tannin-based electrodes are slightly lower compared to those based on resorcinol. Graphical Abstract