O/N Co‐Doped, Layered Porous Carbon with Mesoporosity up to 99 % for Ultrahigh‐Rate Capability Supercapacitors

Abstract

Ultrahigh-rate capability supercapacitors that can tolerate charging/discharging at ultrahigh current density are particularly attractive for high-power applications. At present, mesopore-engineering and heteroatom-doping have been proven to be the effective ways for concurrently enhancing energy density and rate capability. Herein, we report the fabrication of O/N-codoped mesoporous carbons with ultrahigh mesoporosity and well-defined mesopores by one-step Na 2 CO 3-activation of covalent triazine-based frameworks that derive from 2,4,6-tris(4cyanophenoxy)-1,3,5-triazine monomer (CTFO) at 800-1000°C. The as-obtained O/N-co-doped carbon (CTFC-900) with up to 99 % mesoporosity possesses a layered structure together with a high specific surface area (2425 m 2 g À 1) and a high N/O content (6.98 at% N and 10.32 at% O). Owing to these merits, the supercapacitor based on CTFC-900 electrode exhibited a high specific capacitance of 287 F g À 1 at 1.0 A g À 1 and an ultrahigh rate capability of 66.1 % at 1-1000 A g À 1 in alkaline electrolyte. Moreover, the CTFC-900-based supercapacitor in neutral electrolyte achieved both high energy density (32.2 Wh kg À 1) and high power density (187 kW kg À 1).

Fluorine/Nitrogen Co-Doped Porous Carbons Derived from Covalent Triazine Frameworks for High-Performance Supercapacitors

“…Figure 2b shows that all FNCs possess pore sizes of ∼0.28 and 3.7 nm. The microporous structure (<2 nm), which may be mainly derived from the unordered stacking layers of the precursors, is believed to maximize the capacitance originated from the contribution of EDLC, 8,18,19 while mesopores (2−50 nm) are expected to provide larger channels for ion exchange and thus…”

“…V meso (cm achieve preferable rate performance. 8,18,19 The specific surface areas and porosity of the FNCs are summarized in Table 1.…”

“…Nevertheless, a higher temperature of 800 °C did not prompt a higher S BET and porosity, indicating that further decomposition of the FCTF may lead to partial collapse of S micro and S BET was lowered as well. 19 The larger S BET and S micro of FNC-700 compared to those of FNC-600 and FNC-800 are assumed to contribute to the better electrochemical behaviors, especially at lower scan rates for FNC-700. FNC-700 has similar S meso but much higher S micro compared to that of FNC-600 and FNC-800.…”

Preparation of Porous Carbons Using NaOH, K2CO3, Na2CO3 and Na2S2O3 Activating Agents and Their Supercapacitor Application: A Comparative Study

“…Therefore, it is necessary to find a low dosage and effective activating agents to produce as‐targeted characteristic porous carbon. To date, several less corrosive pore‐forming agents have reported such as Na 2 CO 3 , [20] Na 2 S 2 O 4 , [21] K 2 C 2 O 4 , [22] and COOK, [23] etc. to overcome the abovementioned issues [24,25] .…”

Advances of Carbon-Based Materials for Lithium Metal Anodes

“…The surface chemistry of carbon-based materials can be easily modified to improve the binding properties. Consequently, doping or co-doping with different heteroatoms (N, S, P) (Wei et al, 2019;Liu et al, 2020;Ma et al, 2020; makes the carbon-based materials exhibit further enhancement of the electrocatalytic activity. Owing to these diversified functions of carbon-based materials, they have been intensively used to ameliorate the challenges of LMBs (Zuo et al, 2018;Xue et al, 2019;Huang et al, 2020).…”