FeCoSe2 nanosheets@NiCoSe2 nanoflowers encapsulated in a graphene network are fabricated for hybrid supercapacitors.

A high-performance hybrid supercapacitor by encapsulating binder-less FeCoSe2 nanosheets@NiCoSe2 nanoflowers in a graphene network

Anticorrosive performance of green deep eutectic solvent for electrochemical capacitor

Using biomass waste as supercapacitor material has been one of themost widely used method owing to high performance, low cost and sustainable green economy. Herein, we employ ramuli mori, a...

High-performance supercapacitors based on amorphous carbon derived from natural ramulusmori

The controlled chemical functionalization of graphene oxide (GO) represents a powerful strategy to finely tune its physical and chemical properties toward applications in energy storage. Herein, an unprecedented approach for the GO modification with thioamide‐based polymers featuring numerous heteroatoms (S,N,O) is reported, which is instrumental for achieving superior electrochemical performance in symmetric supercapacitors. While the electrochemical investigations in aqueous electrolytes reveal specific capacitance of 221 F g−1 at 1 A g−1, the use of organic media allows the specific capacitance to be boosted up to 340 F g−1. Additionally, the increase of operating window yields energy densities as high as 94.4 Wh kg−1, thereby exceeding state‐of‐the‐art performances of GO‐based supercapacitors. Furthermore, the symmetric devices exhibit great robustness in both aqueous and organic electrolytes as evidenced by an excellent stability after 5000 working cycles (>98% in H2SO4 and >90% in TEABF4/ACN).

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/smsc.202300013

A Graphene Oxide–Thioamide Polymer Hybrid for High‐Performance Supercapacitor Electrodes

Synthesis of three-dimensional (3D) porous current collectors is a pioneering strategy to improve the energy density and power density of wire-like supercapacitors. The strategy is further promoted in this work...

Energy-dense wire-like supercapacitors based on scalable three-dimensional porous metal-graphene oxide skeleton electrodes

Supercapacitors are characterized by high power density, but a bottleneck exists regarding their limited energy density due to the conflict between achieving high mass loading and high specific capacitance with the current structural design. Although there have been concerted efforts to develop supercapacitors with high specific capacitance using nanostructured materials, the total mass loading of active materials is confined by their nano-scale thickness. Here we report an effective strategy to integrate active materials and current collectors through binding active materials and current collectors together in a 3D style. Contrary to the conventional configuration, hollow active materials were confined inside nano-scale current collectors in this work. The resulting nano-scale electrode materials could be compressed together in a scalable style to form nanoporous Fe3O4@Ni freestanding electrodes at the desired scale. Consequently, symmetric supercapacitors were fabricated by Fe3O4@Ni electrodes, and showed a capacitance of 11.2 F cm−2, corresponding to an energy density of 94.4 mW h cm−3. The supercapacitor also exhibited an excellent cyclic capability with a capacitance retention of 107% after 10 000 cycles. The scalability of the electrode materials could be further enhanced by the addition of multiwalled carbon nanotubes (MCNTs) during the synthesis process, and the resulting 0.665-thick Fe3O4-MCNTs@Ni electrode with an Fe3O4 content of 79.4 mg cm−2 exhibited a superhigh areal capacitance of 82.6 F cm−2 as well as a high volumetric capacitance of 1242 F cm−3. This work demonstrates that large mass loading, large specific capacitance, high energy density, and good cyclability of supercapacitors can be achieved simultaneously through the effective structural design of electrodes at the multi-scale.

Ruitao Zhou

Papers

Scalable electrode materials with nanoporous current collector shells for supercapacitors with ultrahigh areal and volumetric capacitances