September 24, 2022

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Engineering the grain boundary: a promising s

The self-supporting electrode material without binder exhibits better energy storage capacity and better stability than conventional powder electrodes because of its lower electrical resistance.

Among various metallic compositions with pseudocapacitive properties, Ni and Co compounds, including their (hydro)oxides, sulfides and phosphides, are highly theoretical due to their transition from Ni and Co atoms of different valence states attention has been paid to capacitance.

Professor Hui Wang and co-workers from the School of Chemical Engineering at Qingdao University of Science and Technology obtained NiCoP electrode materials with high specific capacity by doping phosphorus element into nickel-cobalt-based electrode materials. This research was published online in Frontiers of Chemical Science and Engineering on February 25, 2022.

The grain boundary-rich NiCoP4O12/NiCoP electrode material was prepared by a three-step method. Firstly, the precursor of nickel and cobalt was prepared by simple hydrothermal treatment, followed by one-step heat treatment, which was converted into oxide of nickel and cobalt, and finally the composite material of phosphide was obtained by vapor deposition method. By changing the phosphating time, different grain boundaries could be obtained.

In the three-step synthesis study, the researchers studied the structure, morphology and electrochemical properties of the samples through a series of related physical characterizations and electrochemical performance tests, and successfully confirmed the preparation of nanostructures stacked by crystal grains. The line array structure was studied, and the key to improving the performance was that the rich grain boundary density greatly increased the active sites of the electrode material, resulting in a greatly improved electrochemical performance of the material.

The final research results show that the nickel-cobalt-based electrode material doped with phosphorus has a high specific capacitance of 507.8 μAh·cm−2 at 1 mA·cm−2 due to phosphorus doping and rich grain boundary density, and realizes 88.5% ultra-stable ability after 10000 cycles.

This design of abundant grain boundaries within the cell is an interesting strategy to achieve higher active site densities. In addition, the electronic structure of the grain boundaries is also tuned compared to the in-plane active sites, which promotes the activity of the array electrodes. The development of grain boundary-rich arrays is another innovative direction for the improvement of electrochemical capacitors.

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Reference: Mengqi Cui et al (2022). Engineering the grain boundary: a promising strategy to configure NiCoP4O12/NiCoP nanowire arrays for ultra-stable supercapacitor, Frontiers of Chemical Science and Engineering DOI: 10.1007/s11705-021-2132-0

About Higher Education Press

Founded in May 1954, Higher Education Press Limited Company (HEP), affiliated with the Ministry of Education, is one of the earliest institutions committed to educational publishing after the establishment of P. R. China in 1949. After striving for six decades, HEP has developed into a major comprehensive publisher, with products in various forms and at different levels. Both for import and export, HEP has been striving to fill in the gap of domestic and foreign markets and meet the demand of global customers by collaborating with more than 200 partners throughout the world and selling products and services in 32 languages globally. Now, HEP ranks among China’s top publishers in terms of copyright export volume and the world’s top 50 largest publishing enterprises in terms of comprehensive strength.

The Frontiers Journals series published by HEP includes 28 English academic journals, covering the largest academic fields in China at present. Among the series, 13 have been indexed by SCI, 6 by EI, 2 by MEDLINE, 1 by A&HCI. HEP’s academic monographs have won about 300 different kinds of publishing funds and awards both at home and abroad.

About Frontiers of Chemical Science and Engineering

Frontiers of Chemical Science and Engineering presents the latest developments in chemical science and engineering, emphasizing emerging and multidisciplinary fields and international trends in research and development. The journal promotes communication and exchange between scientists all over the world. The contents include original reviews, research papers and short communications. Coverage includes catalysis and reaction engineering, clean energy, functional material, nanotechnology and nanoscience, biomaterials and biotechnology, particle technology and multiphase processing, separation science and technology, sustainable technologies and green processing. The Editors-in-Chief are Academician Jingkang Wang from Tianjin University, Academician Qunji Xue from Ningbo Institute of Industrial Technology and Academician Jiongtian Liu from Zhengzhou University. The journal has been indexed by SCI, Ei, CA, ChemWeb, INSPEC, SCOPUS, Source Journals for Chinese Scientific and Technical Papers and Citations, CSCD, etc.


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https://www.eurekalert.org/news-releases/951178