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16. Effects of Central Metal Ion on Binuclear Metal Phthalocyanine-Based Redox Mediator for Lithium Carbonate Decomposition.

Author

Yan, Qinghui, Yan, Linghui, Huang, Haoshen, Chen, Zhengfei, Liu, Zixuan, Zhou, Shaodong, and He, Haiyong

Subjects
METAL ions, LITHIUM-air batteries, COBALT, DENSITY functional theory, OXIDATION-reduction reaction, METAL phthalocyanines
Abstract

Li2CO3 is the most tenacious parasitic solid-state product in lithium–air batteries (LABs). Developing suitable redox mediators (RMs) is an efficient way to address the Li2CO3 issue, but only a few RMs have been investigated to date, and their mechanism of action also remains elusive. Herein, we investigate the effects of the central metal ion in binuclear metal phthalocyanines on the catalysis of Li2CO3 decomposition, namely binuclear cobalt phthalocyanine (bi-CoPc) and binuclear cobalt manganese phthalocyanine (bi-CoMnPc). Density functional theory (DFT) calculations indicate that the key intermediate peroxydicarbonate (*C2O62−) is stabilized by bi-CoPc2+ and bi-CoMnPc3+, which is accountable for their excellent catalytic effects. With one central metal ion substituted by manganese for cobalt, the bi-CoMnPc's second active redox couple shifts from the second Co(II)/Co(III) couple in the central metal ion to the Pc(-2)/Pc(-1) couple in the phthalocyanine ring. In artificial dry air (N2-O2, 78:22, v/v), the LAB cell with bi-CoMnPc in electrolyte exhibited 261 cycles under a fixed capacity of 500 mAh g−1carbon and current density of 100 mA g−1carbon, significantly better than the RM-free cell (62 cycles) and the cell with bi-CoPc (193 cycles). [ABSTRACT FROM AUTHOR]

Published
2024
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26. A high-performance crystalline Ti2O1.3(PO4)1.6/TiO2 carbon-coated composite as an anode for lithium-ion batteries.

Author

Zheng, Yayun, Yi, Yuefo, Yang, Ziyi, Zhou, Wenbin, Wang, Yichao, and Chen, Zhengfei

Subjects
LITHIUM-ion batteries, CARBON composites, GRAPHITIZATION, GLUCOSE
Abstract

A crystalline Ti2O1.3(PO4)1.6/TiO2 carbon-coated composite was synthesized by a glucose-modified hydrothermal method. It shows the highest reversible capacities, excellent rate properties and remarkable cycling performances compared to its counterpart prepared without glucose modification, particularly maintaining a capacity of 233.9 mA h g−1 after 200 cycles at 1000 mA g−1. [ABSTRACT FROM AUTHOR]

Published
2023
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33. Surface Enrichment of Redox Mediator for Long-Cyclable Lithium–Air Batteries

Author

Huang, Shiqiang, Li, Zhendong, Liu, Zixuan, Yan, Qinghui, Ma, Bingyan, Wang, Deyu, Wei, Feng, Chen, Zhengfei, and He, Haiyong

Abstract

Three cobalt porphyrine derivatives, cobalt tetramethoxyphenyl porphyrin (CoTMPP), cobalt mesotetraphenylporphyrin (CoTPP), and cobalt octaethyl-porphyrin (CoOEP), were used as redox mediators (RMs) in the Li–air battery. Through cyclic voltammetry tests and calculation with Randles-Ševčı́k and Brown-Anson equations, it was found that the redox reactions of RMs are controlled by adsorption on the cathode surface rather than diffusion, and the side substituent groups exert critical influences on the RM adsorbability and cell cyclability. Owing to its highest adsorbability as well as its capability to decompose Li2CO3, CoTMPP enables a Li–air cell to operate 200 cycles under 100 mA g–1carbonand 500 mAh g–1carboneven without solid-state electrolyte membrane to suppress RM shuttling and deactivation.

Published
2023
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46. Heterogeneous catalysts for the hydrogenation of amine/alkali hydroxide solvent captured CO2 to formate: A review.

Author

Li, Lichun, Chen, Xiangcan, Chen, Zhengfei, Gao, Ruiqin, Yu, Hangdi, Yuan, Tian, Liu, Zongjian, and Maeder, Marcel

Subjects
HETEROGENEOUS catalysts, CARBON sequestration, HYDROGENATION, SOLVENTS, ALKALI metals, HYDROXIDES, ALKALIES
Abstract

Carbon capture and utilization technology is one of the medium‐term technology options to reduce CO2 emissions while producing value‐added fuels and chemical products. The integrated CO2 capture and hydrogenation process is an encouraging replacement to the conventional decoupled CO2 capture and hydrogenation process, which allows direct utilization of captured CO2 thus eliminating the energy‐intensive CO2 desorption and compression steps in the typical carbon capture and storage (CCS) process. The hydrogenation of captured CO2 in amine/alkali hydroxide solvents is the key step to attain the integrated CO2 capture and hydrogenation process. Considering the lack of timely review on the topic of hydrogenation of amine/alkali hydroxide solvent captured CO2 to formate in the presence of heterogeneous catalysts, a summary of such process with different capturing solvents and heterogeneous catalyst were critically summarized and briefly reviewed in the current paper. The main goal of this review is to provide fundamental insights and guidance for the future design of heterogeneous catalysts for the hydrogenation of captured CO2 in amine/alkali metal hydroxide‐based solvents. Future research directions to advance the process of hydrogenation of captured CO2 were also recommended. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Published
2021
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49. Partially Naked Fluoride in Solvate Ionic Liquids

Author

Chen, Zhengfei, primary, Tonouchi, Yuto, additional, Matsumoto, Kazuhiko, additional, Saimura, Masayuki, additional, Atkin, Rob, additional, Nagata, Takashi, additional, Katahira, Masato, additional, and Hagiwara, Rika, additional

Published
2018
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