The science and technology of ultracapacitors are reviewed for a number of electrode materials, including carbon, mixed metal oxides, and conducting polymers. More work has been done using microporous carbons than with the other materials and most of the commercially available devices use carbon electrodes and an organic electrolytes. The energy density of these devices is 3¯5 Wh/kg with a power density of 300¯500 W/kg for high efficiency (90¯95%) charge/discharges. Projections of future developments using carbon indicate that energy densities of 10 Wh/kg or higher are likely with power densities of 1¯2 kW/kg. A key problem in the fabrication of these advanced devices is the bonding of the thin electrodes to a current collector such the contact resistance is less than 0.1 cm2. Special attention is given in the paper to comparing the power density characteristics of ultracapacitors and batteries. The comparisons should be made at the same charge/discharge efficiency.

Ultracapacitors: Why, How, and Where is the Technology

The investigation of renewable, cost-effective, and environmentally gracious electrode materials with high adsorption, fast ion/electron transport, and tunable surface chemistry is immediately desirable for the development of next-generation biocompatible energy-storage devices. In recent years, biomass-derived carbon electrode materials for energy storage have attracted significant attention because of their widespread availability, renewable nature, and low cost. More importantly, their inherent uniform and precise biological structures can be utilized as templates for fabricating electrode materials with controlled and well-defined geometries. The current review mainly spotlights on recent research progress towards biomass derived carbon electrode materials include plant, fruit, vegitable, animal waste, and microorganism based carbon electrode materials for supercapacitor applications. And over view of different synthesis methods for conversion and activation of biomass waste are discussed. Furthermore, summary and future research trends in this filed are projected. 

Recent progress on biomass waste derived activated carbon electrode materials for supercapacitors applications—A review

Improving the electrochemical performance of biomass-derived carbon electrode-active materials for supercapacitor applications has recently attracted considerable attention. Herein, we develop hybrid electrode materials from rice-husk-derived porous carbon (RH-C) materials and β-Ni(OH)2 via a facile solid-state reaction strategy comprising two steps. The prepared RH-C/Ni(OH)2 (C-Ni) was investigated using scanning electron microscopy (SEM) (energy-dispersive X-ray spectrometer (EDS)), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) to acquire the physical and chemical information, which was used to demonstrate the successful fabrication of C-Ni. Thermogravimetric analysis (TGA) measurement results confirmed that the thermal stability of C-Ni changed due to the presence of Ni(OH)2. As expected, C-Ni possesses a high capacitance of ∼952 F/g at a current density of 1.0 A/g. This result is higher than that of pure biomass-based carbon materials under the three-electrode system. This facile preparation method, which was used to synthesize the electrode-active materials, can extend to the value-added utility of other waste biomass materials as high-performing supercapacitor electrodes for energy storage applications.

https://pubs.acs.org/doi/pdf/10.1021/acsomega.0c04117

Promising Rice-Husk-Derived Carbon/Ni(OH)2 Composite Materials as a High-Performing Supercapacitor Electrode.

A series of novel indole Schiff base derivatives (2a–2t) containing a 1,3,4-thiadiazole scaffold modified with a thioether group were synthesized, and their structures were confirmed using FT-IR, 1H NMR, 13C NMR, and HR-MS. In addition, the antifungal activity of synthesized indole derivatives was investigated against Fusarium graminearum (F. graminearum), Fusarium oxysporum (F. oxysporum), Fusarium moniliforme (F. moniliforme), Curvularia lunata (C. lunata), and Phytophthora parasitica var. nicotiana (P. p. var. nicotianae) using the mycelium growth rate method. Among the synthesized indole derivatives, compound 2j showed the highest inhibition rates of 100%, 95.7%, 89%, and 76.5% at a concentration of 500 μg/mL against F. graminearum, F. oxysporum, F. moniliforme, and P. p. var. nicotianae, respectively. Similarly, compounds 2j and 2q exhibited higher inhibition rates of 81.9% and 83.7% at a concentration of 500 μg/mL against C. lunata. In addition, compound 2j has been recognized as a potential compound for further investigation in the field of fungicides.

/pdf/synthesis-of-novel-indole-schiff-base-compounds-and-their-tjgyewyz.pdf

Synthesis of Novel Indole Schiff Base Compounds and Their Antifungal Activities

Silver nanoparticles bridging segregated hexagonal boron nitride networks for enhancing the thermal conductivity of polystyrene composites

Biomass straws are often regarding as agricultural waste, usually burned off in rural areas, which results in severe resource waste and air pollution. In this work, biomass-based porous carbon material with a lamellar microstructure is obtained via simple hydrothermal and subsequent KOH activation, the optimum activate process is determined by the proportion of activator. Scanning electron microscopy (SEM) and nitrogen adsorption techniques are conducted to investigate the physical properties of the materials. Cyclic voltammetry and constant current discharge/charge in the three-electrode system and symmetrical double-layer capacitors results indicate the best electrochemical performance of SCA-1.5 electrode material, with a capacity of 250.0 F g -1  at 1.0 A g -1 . And notably, high recycling stability at a high cycling rate of 1.0 A g -1  after 18,000 cycles.

/pdf/biomass-straw-based-activated-porous-carbon-materials-for-1jdzfhh2fe.pdf

Xinle Zhang

Papers

Biomass Straw Based Activated Porous Carbon Materials for High-Performance Supercapacitors

High thermal conductivity of epoxy-based composites utilizing 3D porous boron nitride framework

Synthesis of spiropyrans via the Rh(III)-catalyzed annulation of 3-aryl-2H-benzo[b][1,4]oxazines with diazo ketoesters.

Detecting geothermal anomalies using Landsat 8 thermal infrared remote sensing data in the Ruili Basin, Southwest China

Achieving high-temperature resistance and excellent insulation property of epoxy by introducing triazine ring structure