University of Science and Technology Beijing

About: University of Science and Technology Beijing is a education organization based out in Beijing, China. It is known for research contribution in the topics: Microstructure & Alloy. The organization has 41558 authors who have published 44473 publications receiving 623229 citations. The organization is also known as: Beijing Steel and Iron Institute.

Understanding the high-electrocatalytic performance of two-dimensional MoS2 nanosheets and their composite materials

Abstract: Two-dimensional (2D) layered molybdenum disulfide (MoS2) materials have attracted a wide range of attention due to their unique physical and chemical properties as well as their tunable electronic structures. Nowadays, hydrogen evolution reaction (HER) in water splitting is crucial to the cost-effective production of the pure hydrogen fuel, while oxygen reduction reaction (ORR) in fuel cells has been suffering from sluggish reaction kinetics even if a high loading of platinum is applied. In this context, it is of great urgency to develop new catalysts comparable to traditional noble metal catalysts in electrocatalytic activity but composed of earth-abundant elements. In the past decade, 2D layered MoS2-based materials have demonstrated great potential as non-noble metal catalysts for both HER and ORR to meet the two aforementioned requirements. To this end, we conduct this survey aimed at summarizing the recent efforts in addressing electrocatalytic issues involved in HER and ORR activities using 2D MoS2 materials. Starting from an introduction on the superiorities of MoS2-based electrocatalysts for HER and ORR in this review, we then discuss the critical obstacles faced by MoS2 nanosheets with respect to their catalytic activities. Subsequently, we summarize the recent strategies for improving the catalytic activity of MoS2-based materials and the updated advances. In the end, we suggest potential pathways for high-catalytic performance comparable to those of their noble-metal counterparts and give some perspectives on practical applications of MoS2-based materials in the future. The insightful views from this review are believed to be greatly beneficial for accomplishing a better understanding on 2D layered MoS2-based material catalysts in electrocatalytic activities.

A review of modeling, acquisition, and application of lithium-ion battery impedance for onboard battery management

Abstract: Impedance is closely related to the internal physical and chemical processes of lithium-ion batteries. And the properties of the processes can be characterized and thus more detailed information be provided based on it. In the past decades, the impedance is frequently reported as a powerful tool used in the field of lithium-ion battery state estimation and diagnosis. This paper reviews more than 170 papers and organizes the related research according to three themes of impedance modeling, acquisition, and application under the premise of electric vehicle implementation. The strength and weaknesses of the research in each theme are discussed. Based on the research, the possibility and the value of impedance in onboard battery management are revealed. However, challenges are still faced due to the cost limitations, the complex vehicular conditions, and the time-varying battery states. The unsolved issues are summarized in the conclusion. To realize a more smart battery management system with the impedance, more significant work is still needed.

Harvesting Ambient Vibration Energy over a Wide Frequency Range for Self-Powered Electronics

Abstract: Vibration is one of the most common energy sources in ambient environment. Harvesting vibration energy is a promising route to sustainably drive small electronics. This work introduces an approach to scavenge vibrational energy over a wide frequency range as an exclusive power source for continuous operation of electronics. An elastic multiunit triboelectric nanogenerator (TENG) is rationally designed to efficiently harvest low-frequency vibration energy, which can provide a maximum instantaneous output power density of 102 W·m–3 at as low as 7 Hz and maintain its stable current outputs from 5 to 25 Hz. A self-charging power unit (SCPU) combining the TENG and a 10 mF supercapacitor gives a continuous direct current (DC) power delivery of 1.14 mW at a power management efficiency of 45.6% at 20 Hz. The performance of the SCPU can be further enhanced by a specially designed power management circuit, with a continuous DC power of 2 mW and power management efficiency of 60% at 7 Hz. Electronics such as a therm...