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15. Equivalent Circuit Model Recognition of Electrochemical Impedance Spectroscopy via Machine Learning

Author

Zhu, Shan, Sun, Xinyang, Wang, Yuxuan, Zhao, Naiqin, and Sha, Junwei

Subjects
Physics - Data Analysis, Statistics and Probability, Physics - Applied Physics, Physics - Computational Physics
Abstract

Electrochemical impedance spectroscopy (EIS) is an effective method for studying the electrochemical systems. The interpretation of EIS is the biggest challenge in this technology, which requires reasonable modeling. However, the modeling of EIS is of great subjectivity, meaning that there may be several models to fit the same set of data. In order to overcome the uncertainty and triviality of human analysis, this research uses machine learning to carry out EIS pattern recognition. Raw EIS data and their equivalent circuit models were collected from the literature, and the support vector machine (SVM) was used to analyze these data. As the result, we addresses the classification of EIS and recognizing their equivalent circuit models with accuracies of up to 78%. This study demonstrates the great potential of machine learning in electrochemical researches.

Published
2019

17. High‐Pressure‐Field Induced Synthesis of Ultrafine‐Sized High‐Entropy Compounds with Excellent Sodium‐Ion Storage

Author

Liang, Ming, primary, Xie, Haonan, additional, chen, biao, additional, Qin, Hongye, additional, Zhang, Hanwen, additional, Wang, Jingyi, additional, Sha, Junwei, additional, Ma, Liying, additional, Liu, Enzuo, additional, Kang, Jianli, additional, Shi, Chunsheng, additional, He, Fang, additional, Han, Xiaopeng, additional, Hu, Wenbin, additional, Zhao, Naiqin, additional, and He, Chunnian, additional

Published
2024
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28. Multi-scale synergistic regulation of hierarchical porous Ni@NiSe cathodes with low voltage gap, high capacity and long-term cycling stability in Li–CO2 battery.

Author

Shi, Yating, Xie, Haonan, Ma, Liying, Chen, Biao, Kang, Jianli, Shi, Chunsheng, He, Chunnian, and Sha, Junwei

Subjects
LOW voltage systems, ELECTRONIC band structure, CATHODES, ELECTRIC batteries, LITHIUM cells, ENERGY consumption, METAL-air batteries
Abstract

The Li–CO2 battery often suffers from high overpotential and limited capacity due to the challenges associated with the adsorption of Li+ and CO2 and the decomposition of Li2CO3. Herein, hexagonal rich-stepped NiSe crystals are in situ achieved on a three-dimensional (3D) free-standing porous Ni skeleton with double continuous channel architecture (namely p-Ni@NiSe-50) through an in situ selenization process. Structural characterization and theoretical calculation are applied to demonstrate the synergistic effects of marco/microstructural design and electronic band structure regulation. As a result, the adsorption/desorption of Li+ and CO2 and the formation/decomposition of Li2CO3 are effectively promoted, simultaneously, enabling an enhanced capacity and reversibility of p-Ni@NiSe-50 as the cathode of Li–CO2 battery. An ultra-low overpotential of 0.46 V and a remarkably high energy efficiency of 83.8% (20 μA cm−2) are achieved, along with a high full discharge specific capacity of 8844 μAh cm−2. Excellent long-term cycling stability (cycles up to 1000 h at a voltage gap of 1.14 V) of p-Ni@NiSe-50 is also obtained. The results of this work would provide a new insight and strategy to develop high-performance alkali metal-air batteries. Multi-scale synergistic effect of combining the cathode macroscopic structure design and the microscopic band structure design of NiSe was demonstrated to promote the adsorption of Li+ and CO2, as well as the decomposition of Li2CO3, so as to achieve ultra-low voltage gap and high capacity of Li-CO2 batteries. [ABSTRACT FROM AUTHOR]

Published
2024
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29. FeCo Alloy Nanoparticles on Porous Carbon for Zinc–Air Batteries.

Author

Sun, Di, Cui, Haokang, Sha, Junwei, Chen, Biao, Shi, Chunsheng, Kang, Jianli, and Ma, Liying

Abstract

Bifunctional catalysts (OER/ORR) require lower overpotentials and fast mass transfer, but developing transition metal-based bifunctional catalysts that can satisfy these requirements remains a major challenge. Herein, a composite consisting of FeCo alloy nanoparticles uniformly loaded on three-dimensional (3D) hierarchical porous nitrogen-doped carbon (FeCo/HP-NC) is rationally designed. The electronic modulation of the FeCo alloy can provide a favorable electronic structure for the OER/OER reaction, while the hierarchical porous carbon structure can facilitate not only the accessible channels but also the mass transfer for electrocatalytic reactions. Thus, FeCo/HP-NC provides modest overpotentials (E1/2 = 0.83 V, η = 0.335 V). In particular, when compared with commercially available noble catalysts, FeCo/HP-NC offers a higher power density, more stable voltage (1.43 V), and stability that exceeds 300 h as the cathode. As for this investigation, strategies for increasing the catalytic performance of oxygen electrocatalysis and the power density of energy storage applications could be proposed. [ABSTRACT FROM AUTHOR]

Published
2024
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30. Ultrathin Porous Pd Metallene with Amorphous/Crystalline Phase Coexitence as Electrocatalysts for the Oxygen Reduction Reaction.

Author

Cui, Haokang, Chen, Hongpeng, Wang, Xixi, Jiang, Yicheng, Zhang, Yimin, Sun, Di, Chen, Zanyu, Liu, Ying, Sha, Junwei, Chen, Biao, Shi, Chunsheng, Kang, Jianli, Liu, Enzuo, and Ma, Liying

Abstract

The development of efficient nonplatinum electrocatalysts with enhanced oxygen reduction reaction (ORR) activity and stability is of crucial importance for the commercial application of fuel cells and metal–air batteries. Metallenes exhibit excellent performance in energy and catalysis due to their unique physicochemical and electronic properties. In particular, the ultrahigh proportion of under-coordinated metal atomic sites in metallenes enhances the atom utilization and intrinsic activity, which endows them with considerable potential for catalytic applications. Herein, the synthesized two-dimensional (2D) ultrathin porous Pd metallene with amorphous/crystalline phase coexistence exhibits enhanced alkaline oxygen reduction properties, as evidenced by four-electron selectivity, lower overpotential (E1/2 = 0.944 V), high mass activity (MA = 1.44 mA/μgPd), and solid stability (only loss of 7 mV in half-wave potential after 10,000 potential cycles). Such high performance of Pd metallene is attributed to amorphous/crystalline heterophases, 2D morphology, and porous structure. DFT calculations demonstrate that the ORR catalytic performance can be effectively promoted by the amorphous structure with a modulated electronic structure. The amorphous/crystalline coexisting porous Pd metallene with excellent catalytic performance can provide the reference for metallene materials design in various fields. This study presents a scientific basis to understand the mechanism of 2D amorphous phase nanostructures for boosting the electrocatalytic performance. [ABSTRACT FROM AUTHOR]

Published
2024
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