• Energy Research

AbstractElectrode and electrolyte materials with higher performance, longer life, and lower cost need to be developed, given the substantial growing demand for advanced electrochemical energy systems. Lignin, the second most abundant natural polymer, has been successfully demonstrated to be a viable precursor or feedstock for the preparation of high‐performance electrochemical energy materials and components such as electrodes, electrolyte additives, membrane separators, and binders. Moreover, techno‐economic analyses indicate that it is possible to prepare cost‐effective carbon structures from lignin at engineering scale, in contrast with current carbon products. These facts suggest that the scalable conversion of lignin into high‐value energy materials will offer a promising pathway to not only promote the utilization and valorization of lignin but also boost the development of advanced electrochemical energy systems. This review examines cutting‐edge renewable energy materials derived from various lignin compounds and their applications in electrochemical energy systems with an emphasis on supercapacitors, rechargeable batteries, and fuel cells. Meanwhile, this review also aims to carve out the critical barriers for lignin‐derived high‐performance materials for energy applications, and to identify viable approaches for the synthesis of sustainable new energy materials. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd

Sensing materials play a key role in the successful implementation of electrochemical sensors, and nanotechnology has emerged as an important and rapidly growing field for stimulating the innovation of high-performance sensors. The fabrication, characterization, and evaluation of the nanostructured electrodes are therefore a focus of this field. Compared to a variety of dry and wet technologies which have been extensively developed for this purpose, electrochemical methods are typically convenient, highly effective, and potentially low-cost for the production of different nanostructures. This minireview is designed to introduce a unique electrochemical method - electrolytic metal-atom enabled manufacturing (EM2) and its application in electrochemical sensors. The EM2 technique employs electrolytic metal atoms generated from their corresponding salt precursor as a tool to nanostructure a wide range of substrate electrodes used in electrochemical sensors, based on a one-pot electrochemical deposition and dissolution of the metal atoms in the same electrolyte bath. Briefly, the metal atoms are electrodeposited on a substrate electrode during the cathode reduction, and they are selectively removed from the substrate during the subsequent anode oxidation. Because of the interactions between the electrolytic metal atoms and the substrate atoms, the repetitive electrodeposition and dissolution of the former on the substrate enable the nanostructuration of the substrate, particularly within its surface layers. The nanostructured electrodes have demonstrated very attractive performance for the determination of numerous analytes, such as high sensitivity and selectivity, high interference tolerance, and low detection limits. However, the EM2 technique and the application of the resulting nanostructured electrodes in electrochemical sensors and beyond have still been very limitedly investigated. In order to bring the community from academic, industries, agencies, and customers together to develop the EM2 technique and advance electrochemical sensor systems, this minireview will introduce the thermodynamic and kinetic fundamentals of this technique, the characterization of resulting nanostructures, the analysis of their electrochemical behavior, and the implementation of this technique for the development of advanced sensor electrodes. Finally, an outlook with a focus on further research areas is provided.

An electrolytic renewable nitrogen fertilizer process that utilizes wind-generated electricity, N{sub 2} extracted from air, and syngas produced via the gasification of biomass to produce nitrogen fertilizer ammonia was developed at the University of North Dakota Energy & Environmental Research Center. This novel process provides an important way to directly utilize biosyngas generated mainly via the biomass gasification in place of the high-purity hydrogen which is required for Haber Bosch-based production of the fertilizer for the production of the widely used nitrogen fertilizers. Our preliminary economic projection shows that the economic competitiveness of the electrochemical nitrogen fertilizer process strongly depends upon the cost of hydrogen gas and the cost of electricity. It is therefore expected the cost of nitrogen fertilizer production could be considerably decreased owing to the direct use of cost-effective 'hydrogen-equivalent' biosyngas compared to the high-purity hydrogen. The technical feasibility of the electrolytic process has been proven via studying ammonia production using humidified carbon monoxide as the hydrogen-equivalent vs. the high-purity hydrogen. Process optimization efforts have been focused on the development of catalysts for ammonia formation, electrolytic membrane systems, and membrane-electrode assemblies. The status of the electrochemical ammonia process is characterized by a current efficiency of 43% using more » humidified carbon monoxide as a feedstock to the anode chamber and a current efficiency of 56% using high-purity hydrogen as the anode gas feedstock. Further optimization of the electrolytic process for higher current efficiency and decreased energy consumption is ongoing at the EERC. « less