Electrochemical Decomposition of Poly(Vinylidene Fluoride) Binder for a Graphite Negative Electrode in Lithium-Ion Batteries

To clarify the electrochemical decomposition of poly (vinylidene fluoride) (PVdF) used as a binder for lithium-ion batteries while simultaneously verifying the correlation between electrode resistance and the PVdF content in graphite negative electrodes, in this study, we applied lithium bis (trifluoromethanesulfonyl) imide, which suppresses graphite exfoliation, as a salt. As a result, the electrochemical decomposition of PVdF was observed at a higher potential than that at which the electrolyte was decomposed during the reduction process. Additionally, this study demonstrated (through electrochemical impedance spectroscopy analysis) that electrode resistances such as solid electrolyte interface and charge transfer resistance proportionally increased with the PVdF content.

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Electrochemical Properties of Carbon-Coated NbO2 as a Negative Electrode for Lithium-Ion Batteries

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.724.87 ◽

2016 ◽

Vol 724 ◽

pp. 87-91 ◽

Cited By ~ 3

Author(s):

Chang Su Kim ◽

Yong Hoon Cho ◽

Kyoung Soo Park ◽

Soon Ki Jeong ◽

Yang Soo Kim

Keyword(s):

Electrochemical Properties ◽

Lithium Ion Batteries ◽

Ball Milling ◽

Carbon Coating ◽

Electrochemical Impedance ◽

Active Material ◽

Negative Electrode ◽

Lithium Ion ◽

Transfer Resistance ◽

Carbon Coated

We investigated the electrochemical properties of carbon-coated niobium dioxide (NbO2) as a negative electrode material for lithium-ion batteries. Carbon-coated NbO2 powders were synthesized by ball-milling using carbon nanotubes as the carbon source. The carbon-coated NbO2 samples were of smaller particle size compared to the pristine NbO2 samples. The carbon layers were coated non-uniformly on the NbO2 surface. The X-ray diffraction patterns confirmed that the inter-layer distances increased after carbon coating by ball-milling. This lead to decreased charge-transfer resistance, confirmed by electrochemical impedance spectroscopy, allowing electrons and lithium-ions to quickly transfer between the active material and electrolyte. Electrochemical performance, including capacity and initial coulombic efficiency, was therefore improved by carbon coating by ball-milling.

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Carbon Nanotube Paper as Anode for Flexible Lithium-Ion Battery

NANO ◽

10.1142/s1793292016501204 ◽

2016 ◽

Vol 11 (11) ◽

pp. 1650120 ◽

Cited By ~ 6

Author(s):

Xiaogang Sun ◽

Zhenhong Liu ◽

Neng Li ◽

Xiaoyong Wu ◽

Yanyan Nie ◽

...

Keyword(s):

Carbon Nanotube ◽

Electrochemical Performance ◽

Lithium Ion Battery ◽

Electrochemical Impedance ◽

Negative Electrode ◽

Lithium Ion ◽

Charge Transfer Resistance ◽

Electrochemical Performances ◽

Multiwalled Carbon ◽

Transfer Resistance

In this investigation, multiwalled carbon nanotube (MWCNT) paper consists of MWCNTs and cellulose was fabricated by traditional paper-making method. It was applied directly as negative electrode in flexible lithium ion battery to replace ordinary electrode which is combined with anode material and current collector. The electrochemical performances of the as-produced MWCNT paper (AMP) and carbonized MWCNT paper (CMP) were evaluated in this study. The morphology and structure of the MWCNT papers were observed by scanning electron microscopy (SEM). The electrochemical performance of the battery was operated by cell test and electrochemical impedance spectroscopy (EIS) measurement. The charging and discharging results indicated that the CMP behaves with higher capacity than AMP. And the EIS analysis showed that a lower charge transfer resistance can be obtained in the CMP. The excellent electrochemical performance verifies the feasibility of MWCNT papers as a promising candidate for the anode in flexible lithium ion battery.

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Enhanced Electrochemical Performance of LiFePO4 Originating from the Synergistic Effect of ZnO and C Co-Modification

Nanomaterials ◽

10.3390/nano11010012 ◽

2020 ◽

Vol 11 (1) ◽

pp. 12

Author(s):

Xiaohua Chen ◽

Yong Li ◽

Juan Wang

Keyword(s):

Zinc Oxide ◽

Charge Transfer ◽

Lithium Ion Batteries ◽

Electrochemical Impedance ◽

Lithium Ion ◽

Charge Transfer Resistance ◽

Electron Conductivity ◽

Spherical Particles ◽

Commercial Application ◽

Transfer Resistance

Olivine-structure LiFePO4 is considered as promising cathode materials for lithium-ion batteries. However, the material always sustains poor electron conductivity, severely hindering its further commercial application. In this work, zinc oxide and carbon co-modified LiFePO4 nanomaterials (LFP/C-ZnO) were prepared by an inorganic-based hydrothermal route, which vastly boosts its performance. The sample of LFP/C-xZnO (x = 3 wt%) exhibited well-dispersed spherical particles and remarkable cycling stability (initial discharge capacities of 138.7 mAh/g at 0.1 C, maintained 94.8% of the initial capacity after 50 cycles at 0.1 C). In addition, the cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) disclose the reduced charge transfer resistance from 296 to 102 Ω. These suggest that zinc oxide and carbon modification could effectively minimize charge transfer resistance, improve contact area, and buffer the diffusion barrier, including electron conductivity and the electrochemical property. Our study provides a simple and efficient strategy to design and optimize promising olivine-structural cathodes for lithium-ion batteries.

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