Evaluation of Graphite Materials as Anodes for Lithium-Ion Batteries

Cao, Fei; Barsukov, I.; Bang, Hyun Joo; Zaleski, Peter; Prakash, Jai

doi:10.1149/1.1393942

Cited by 57 publications

(41 citation statements)

References 16 publications

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“…47 The coherence length of the graphite crystallites along the c axis L C can be estimated from the broadening of the (002) reflection using the Scherrer equation as summarized in Table S4. 7 As seen in Figure 6a, SCMG-BH graphite had the broadest (002) diffraction peak among the pristine samples, corresponding to the smallest crystallite size of 53 nm and consistent with our observation in the SEM images. The grain size of SLC 1520T was approximately three times larger at 162 nm.…”

Section: Resultssupporting

confidence: 89%

“…48 The relative amount of the hexagonal and rhombohedral phases can be estimated by comparing the integrated intensities of (101) and (002) diffraction peaks, using a structure factor of 0.754. 7 While the rhombohedral phase does not significantly impact…”

Section: Resultsmentioning

confidence: 98%

“…7 However, there seems no optimal rhombohedral phase ratio for long-term cycling. While A12, MAGE and SLC 1520T have similar rhombohedral phase fractions (Table S5), their capacity retention in long-term cycling varied considerably.…”

Section: A1842mentioning

confidence: 99%

“…5,6 In addition to its low cost and non-toxicity, graphite has a lowest average voltage (150 mV vs. Li/Li + ) and the flat voltage profile, rendering a high overall cell voltage. 7 Graphite also displays a very low voltage hysteresis, which in turn results in high energy efficiency. 8 For applications in lithium-ion batteries, many properties of the graphite powders must be optimized including crystallinity, particle size, morphology, and surface chemistry.…”

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Selecting the Best Graphite for Long-Life, High-Energy Li-Ion Batteries

Mao

Wood

David

et al. 2018

J. Electrochem. Soc.

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Most lithium-ion batteries still rely on intercalation-type graphite materials for anodes, so it is important to consider their role in full cells for applications in electric vehicles. Here, we systematically evaluate the chemical and physical properties of six commerciallyavailable natural and synthetic graphites to establish which factors have the greatest impact on the cycling stability of full cells with nickel-rich LiNi0.8Mn0.1Co0.1O2 (NMC811) cathodes. Electrochemical data and post-mortem characterization explain the origin of capacity fade. The NMC811 cathode shows large irreversible capacity loss and impedance growth, accounting for much of full cell degradation. However, six graphite anodes demonstrate significant differences with respect to structural change, surface area, impedance growth, and SEI chemistry, which impact overall capacity retention. We found long cycle life correlated most strongly with stable graphite crystallite size. In addition, graphites with lower surface area generally had higher coulombic efficiencies during formation cycles, which led to more stable long-term cycling. The best graphite screened here enables a capacity retention around 90% in full pouch cells over extensive long-term cycling compared to only 82% for cells with the lowest performing graphite. The results show that optimal graphite selection improves cycling stability of high energy lithium-ion cells. With the booming demands for electric vehicles and electronic devices, high energy density lithium-ion batteries with long cycle life are highly desired. Despite the recent progress in Si 1 and Li metal 2 as future anode materials, graphite still remains the active material of choice for the negative electrode. 3,4 Lithium ions can be intercalated into graphite sheets at various stages like Li x C 12 and Li x C 6 , providing a high specific capacity of 372 mAh/g (∼2.5 times higher than LiCoO 2 ) and high volumetric capacity (similar to LiCoO 2 ) corresponding to LiC 6 . 5,6 In addition to its low cost and non-toxicity, graphite has a lowest average voltage (150 mV vs. Li/Li + ) and the flat voltage profile, rendering a high overall cell voltage. 7 Graphite also displays a very low voltage hysteresis, which in turn results in high energy efficiency. 8 For applications in lithium-ion batteries, many properties of the graphite powders must be optimized including crystallinity, particle size, morphology, and surface chemistry. However, most research effort has been placed on the development and characterization of high performance cathodes, while the impact of the graphite anode on full cell performance has been largely unexplored.Compared to widely used battery cathodes such as LiCoO 2 (140 mAh/g), LiFePO 4 (160 mAh/g), LiNi 1/3 Mn 1/3 Co 1/3 O 2 (160 mAh/g), and LiNi 0.5 Mn 0.3 Co 0.2 O 2 (175 mAh/g), 9-11 nickel-rich LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC811) is delivers a higher specific capacity (180-220 mAh/g), which increases the battery life on a single charge. 12,13 The high capacity arises because Ni is the main red...

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Section: Resultssupporting

confidence: 89%

Section: Resultsmentioning

confidence: 98%

Section: A1842mentioning

confidence: 99%

mentioning

confidence: 99%

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Selecting the Best Graphite for Long-Life, High-Energy Li-Ion Batteries

Mao

Wood

David

et al. 2018

J. Electrochem. Soc.

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“…As we know, when pyrolyzed at a temperature above 2000 O C, carbon materials usually possess large amount of ordered carbon sheets due to the relaxing of the turbostratic disorder and takes on a lithium-insertion characteristic similar to graphite, thus the capacity of carbon materials can be increased [46]. In this case, the BDC-900 sample was heated at 2800 O C for further graphitization to improve its electrochemical performance.…”

Section: Resultsmentioning

confidence: 99%

Bean-dreg-derived carbon materials used as superior anode material for lithium-ion batteries

Xiang

Zhou

et al. 2016

Electrochimica Acta

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-dreg-derived carbon materials used as superior anode material for lithium-ion batteries, Electrochimica Acta http://dx.doi.org/10.1016/j.electacta. 2016.10.202 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. 3. The KOH-activated sample demonstrated enhanced electrochemical performance due to its high surface area and abundant mesoporous structure. Bean-dreg-derived carbon materials used as superior anode material for lithium-ion batteries AbstractThe structures of modified carbons from bean dregs were regulated via graphitization treatment and chemical activation. The microstructure and electrochemical performance were studied using X-ray diffraction, Raman spectrometer, SEM and TEM techniques. The electrochemical performance was investigated using electrochemical methods. After heat-treatment at 2800 O C, the obtained BDC-2800 possessed a high degree of graphitization and showed an outstanding cycling performance, delivering capacity decay from 423 to 396 mAh g -1 at 0.1 C after 100 cycles. The chemical-treated carbons also demonstrated enhanced electrochemical performance, especially for the KOH-treated sample. The BDC-K displayed superior specific charge capacity of 801 mAh g -1 at 0.1 C, and showed an impressive rate capability of 643 mAh g -1 at 1 C. In addition, this sample delivered capacity retention of 94%after 500 cycles at 1 C. This good electrochemical performance was mainly due to its high surface area and abundant mesoporous structure.

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