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5791 KiB

Open AccessFeature PaperArticle

Evaluation of Carbon-Coated Graphite as a Negative Electrode Material for Li-Ion Batteries

by Varvara Sharova, Arianna Moretti, Guinevere A. Giffin, Diogo Vieira Carvalho and Stefano Passerini

C 2017, 3(3), 22; https://0-doi-org.brum.beds.ac.uk/10.3390/c3030022 - 04 Jul 2017

Cited by 23 | Viewed by 11141

Abstract

Low-cost and environmentally-friendly materials are investigated as carbon-coating precursors to modify the surface of commercial graphite for Li-ion battery anodes. The coating procedure and final carbon content are tuned to study the influence of the precursors on the electrochemical performance of graphite. Thermogravimetric [...] Read more.

Low-cost and environmentally-friendly materials are investigated as carbon-coating precursors to modify the surface of commercial graphite for Li-ion battery anodes. The coating procedure and final carbon content are tuned to study the influence of the precursors on the electrochemical performance of graphite. Thermogravimetric analysis (TGA) and Brunauer–Emmett–Teller (BET) surface area analysis are used to characterize the carbon coating content and the surface area, respectively, whereas X-ray diffraction (XRD) and Raman spectroscopy allow tracking of the graphite’s structural changes and surface amorphization. In general, the coating reduces the first cycle coulombic efficiency by 3%–10% compared to pristine graphite due to the increase of the surface area available for the continuous electrolyte decomposition. However, the use of citric acid as a carbon source (5 wt %) improves the rate capability of graphite, resulting in the specific delithiation capacity at 3C of 228 mAh g⁻¹ vs. 211 mAh g⁻¹ for the uncoated graphite. The attempt to reduce the coating amount from 5 wt % to 2 wt % results in a lower rate capability, but the first cycle coulombic efficiency is similar to that of pristine graphite. Full article

(This article belongs to the Special Issue Batteries: Recent Advances in Carbon Materials 2017)

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4598 KiB

Open AccessArticle

Graphene Encapsulated Silicon Carbide Nanocomposites for High and Low Power Energy Storage Applications

by Emiliano Martínez-Periñán, Christopher W. Foster, Michael P. Down, Yan Zhang, Xiaobo Ji, Encarnación Lorenzo, Dmitrijs Kononovs, Anatoly I. Saprykin, Vladimir N. Yakovlev, Georgy A. Pozdnyakov and Craig E. Banks

C 2017, 3(2), 20; https://0-doi-org.brum.beds.ac.uk/10.3390/c3020020 - 20 Jun 2017

Cited by 6 | Viewed by 5338

Abstract

In this paper, a graphene decorated SiC nanomaterial (graphene@SiC) fabricated via a facile adiabatic process was physicochemically characterised, then applied as a supercapacitor material and as an anode within a Li-ion battery (LIB). The reported graphene@SiC nanomaterial demonstrated excellent supercapacitative behaviour with a [...] Read more.

In this paper, a graphene decorated SiC nanomaterial (graphene@SiC) fabricated via a facile adiabatic process was physicochemically characterised, then applied as a supercapacitor material and as an anode within a Li-ion battery (LIB). The reported graphene@SiC nanomaterial demonstrated excellent supercapacitative behaviour with a relatively high power density and specific capacitance of 4800 W·kg⁻¹ and 394 F·g⁻¹, respectively. In terms of its capabilities as an anode within an LIB, the layered-graphene overwhelms the Li-intercalation, which is reflected in the obtained specific capacity of 150 mAh·g⁻¹, with a columbic efficiency of ~99% (after 450 cycles) at a current of 100 mA·g⁻¹. Full article

(This article belongs to the Special Issue Batteries: Recent Advances in Carbon Materials 2017)

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Review

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14 pages, 798 KiB

Open AccessReview

Current Progress of Si/Graphene Nanocomposites for Lithium-Ion Batteries

by Yinjie Cen, Richard D. Sisson, Qingwei Qin and Jianyu Liang

C 2018, 4(1), 18; https://0-doi-org.brum.beds.ac.uk/10.3390/c4010018 - 19 Mar 2018

Cited by 23 | Viewed by 10609

Abstract

The demand for high performance lithium-ion batteries (LIBs) is increasing due to widespread use of portable devices and electric vehicles. Silicon (Si) is one of the most attractive candidate anode materials for next generation LIBs. However, the high-volume change (>300%) during lithium ion [...] Read more.

The demand for high performance lithium-ion batteries (LIBs) is increasing due to widespread use of portable devices and electric vehicles. Silicon (Si) is one of the most attractive candidate anode materials for next generation LIBs. However, the high-volume change (>300%) during lithium ion alloying/de-alloying leads to poor cycle life. When Si is used as the anode, conductive carbon is needed to provide the necessary conductivity. However, the traditional carbon coating method could not overcome the challenges of pulverization and unstable Solid Electrolyte Interphase (SEI) layer during long-term cycling. Since 2010, Si/Graphene composites have been vigorously studied in hopes of providing a material with better cycling performance. This paper reviews current progress of Si/Graphene nanocomposites in LIBs. Different fabrication methods have been studied to synthesize Si/Graphene nanocomposites with promising electrochemical performances. Graphene plays a key enabling role in Si/Graphene anodes. However, the desired properties of graphene for this application have not been systematically studied and understood. Further systematic investigation of the desired graphene properties is suggested to better control the Si/Graphene anode performance. Full article

(This article belongs to the Special Issue Batteries: Recent Advances in Carbon Materials 2017)

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