High energy density and extremely stable supercapacitors based on carbon aerogels with 100% capacitance retention up to 65,000 cycles

Abstract

In terms of ideal future energy storage systems, besides the always-pursued energy/power characteristics, long-term stability is crucial for their practical application. Here, we report a facile and sustainable strategy for the scalable fabrication of carbon aerogels with three-dimensional interconnected nanofiber networks and rationally designed hierarchical porous structures, which are based on the carbonization of bacterial cellulose assisted by the soft template of Zn-1,3,5-benzenetricarboxylic acid. As binder-free electrodes, they deliver a fundamentally enhanced specific capacitance of 352 F ⋅ g–1 at 1 A ⋅ g–1 in a wide potential window (1.2 V, 6 M KOH) in comparison with those of bacterial cellulose–derived carbons (178 F ⋅ g–1) and most activated carbons (usually lower than 250 F ⋅ g–1). The as-assembled supercapacitors exhibit an ultrahigh capacitance of 297 F ⋅ g−1 at 1 A ⋅ g−1, remarkable energy density (14.83 Wh ⋅ kg−1 at 0.60 kW ⋅ kg−1), and extremely high stability, with 100% capacitance retention for up to 65,000 cycles at 6 A ⋅ g−1, representing their superior energy storage performance when compared with that of state-of-the-art supercapacitors of commercial activated carbons and biomass-derived analogs.

Flexible Wood Enhanced Poly(acrylic acid-co-acrylamide)/Quaternized Gelatin Hydrogel Electrolytes for High-Energy-Density Supercapacitors

“…Electrochemical performance of SC-PGW-SINCH at the high potential window. (a) CV curves and (b) GCD profiles within 0–2 V. (c) Ragone plots of SC-PGW-SINCH and performance comparison with previously reported supercapacitors. − (d) CV curves at 50 mV s –1 and (e) GCD profiles at 1.0 A g –1 within different potential windows. (f) Specific capacitances at 1.0 A g –1 within different potential windows (inset: series-connected supercapacitors charge smartphone).…”

Insights into Hierarchical Structure–Property–Application Relationships of Advanced Bacterial Cellulose Materials

“…F,G) Reproduced with permission. [ 186 ] Copyright 2021, National Academy of Sciences. H) Fabrication of free‐standing N‐self‐doped carbon nanofiber (NCNF) aerogels.…”

“…After 65 000 cycles under a current of 6 A g −1 , 100% of the capacitance was still maintained (Figure 17G). [ 186 ] Moreover, CBC can be functionalized by the doping of different chemical elements (e.g., B, N, P, and S) to change its electronic properties, spin structure, and surface chemistry. [ 187 ] This method has been used to successfully prepare a nitrogen self‐doped porous carbon aerogel with a 3D network and cocoon‐like structure for use in all‐solid‐state supercapacitors (Figure 17H).…”

High energy superstable hybrid capacitor with a self‐regulated Zn/electrolyte interface and 3D graphene‐like carbon cathode

“…[13][14][15] Most of the conveyed ZIHCs can afford an energy density (≥100 Wh kg À1 ) far less than that of their counterpart Zn-ion batteries (ZIBs) and LIBs, while their cycling resilience (≥10 000 cycles) drops behind that of carbon-based SCs. [16][17][18][19] Therefore, a wide-ranging sustainable approach is required to prolong the energy storage capacities and increase the power capabilities and cycling consistencies of ZIHCs.…”

“…The inadequate electrochemical parameters of ZIHCs are due to various factors, including the instability of the Zn anode in aqueous electrolytes, inadequate capacitance/capacity of the cathode materials, dissolution of the cathode materials in the bulk electrolyte, low mass loading of the cathode materials (≤2 mg cm −2 ), low ionic conductivity of the electrolytes (≤10 mS cm −2 ), and lower electrochemical stability window (ESW) of ZIHC cells than that of Li‐ion batteries (LIBs) 13–15 . Most of the conveyed ZIHCs can afford an energy density (≥100 Wh kg −1 ) far less than that of their counterpart Zn‐ion batteries (ZIBs) and LIBs, while their cycling resilience (≥10 000 cycles) drops behind that of carbon‐based SCs 16–19 . Therefore, a wide‐ranging sustainable approach is required to prolong the energy storage capacities and increase the power capabilities and cycling consistencies of ZIHCs.…”