Graphites for Lithium‐Ion Cells: The Correlation of the First‐Cycle Charge Loss with the Brunauer‐Emmett‐Teller Surface Area

Winter, Martin; Novák, Petr; Monnier, Alain

doi:10.1149/1.1838281

Cited by 325 publications

(226 citation statements)

References 11 publications

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“…12,21 The small amount of charge consumed at potentials above 1.0 V is mainly associated with the reduction of surface groups, as well as lithium salt decomposition. 22 This effect is more pronounced for the sputtered electrode and is likely associated with the higher surface density of oxygen-rich surface groups which formed upon exposure of the freshly sputtered Mag-10 anode to the air.…”

mentioning

confidence: 99%

An Investigation of the Effect of Graphite Degradation on Irreversible Capacity in Lithium-ion Cells

Hardwick

Marcinek

Beer

et al. 2008

J. Electrochem. Soc.

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The effect of surface structural damage on graphitic anodes, commonly observed in tested Li-ion cells, was investigated. Similar surface structural disorder was artificially induced in Mag-10 synthetic graphite anodes using argon-ion sputtering. Raman microscopy, scanning electron microscopy (SEM) and Brunauer Emmett Teller (BET) measurements confirmed that Ar-ion sputtered Mag-10 electrodes display similar degree of surface degradation as the anodes from tested Li-ion cells. Artificially modified Mag-10 anodes showed double the irreversible charge capacity during the first formation cycle, compared to fresh un-altered anodes. Impedance spectroscopy and Fourier transform infrared (FTIR) spectroscopy on surface modified graphite anodes indicated the formation of a thicker and slightly more resistive SEI layer. Gas for the surface modified electrode with no evidence of elevated M w species for the unmodified electrode. The structural disorder induced in the graphite during long-term cycling maybe responsible for the slow and continuous SEI layer reformation, and consequently, the loss of reversible capacity due to the shift of lithium inventory in cycled Li-ion cells.3

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mentioning

confidence: 99%

An Investigation of the Effect of Graphite Degradation on Irreversible Capacity in Lithium-ion Cells

Hardwick

Marcinek

Beer

et al. 2008

J. Electrochem. Soc.

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“…The larger the surface area, the more capacity is associated with SEI formation, and the results fit with expectations. 20,21 Our results show that for every square meters of surface area of Si, approximately 10 mAh of charge is used for SEI formation with 1 M LiPF 6 FEC/DEC = 1:1 electrolyte. This value is expected to change with different electrolytes.…”

Section: Methodsmentioning

confidence: 79%

Insights from Studying the Origins of Reversible and Irreversible Capacities on Silicon Electrodes

Lee

2016

J. Electrochem. Soc.

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Silicon electrodes can give high capacity as anodes for lithium-ion batteries. However, there has not been much work quantifying the different contributions to the reversible and irreversible capacities. Here, we report the use of an electrochemical approachdepth of discharge test -to separate the charge-discharge capacities of crystalline silicon electrodes into four contributions: (1) SEI formation, (2) lithium accommodation in carbon and binder, (3) lithiation and delithiation of the Si active material, and (4) capacity loss associated with particle cracking and isolation. We find that the intrinsic coulombic efficiency for the crystalline-to-amorphous transition of Si during initial cycle is about 90%, which is independent of particle size. SEI formation is estimated to be about 10 mAh per square meters of active material surface and scales with BET surface area. Mechanical issues and particle isolation are observed in fully discharged electrode when the amount of binder is less than 20%. Capacity limitation prolongs lifetime of Si electrode, but the overall performance is governed by the coulombic efficiency (CE) during cycle. Low CE is due to continual SEI formation with cycling, increase utilization of Si upon cycling, trapping of Li in the material and mechanical failure of the electrode. Silicon has received much attention as a next-generation anode material for lithium-ion battery (LIB) because it can alloy with Li electrochemically with a theoretical capacity of ∼3572 mAh g −1 , corresponding to the formation of Li 15 Si 4 .1,2 Typically, silicon electrodes show poor cycle performance, which is typically attributed to the large volume expansion during lithiation, pulverization of the active material, continuous solid electrolyte interphase (SEI) layer growth, etc. 3-8Advanced imaging and characterizations such as transmission electron microscopy (TEM), nuclear magnetic resonance (NMR), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), timeof-flight secondary ion mass spectrometry (TOF-SIMS) and in-situ dilatometry have helped scientists understand the underlying physical and mechanical interactions, as well as the chemical reactions in silicon electrodes during charge and discharge.9-13 Though, eventually, it is the capacities that can be obtained from charge and discharge in each cycle, and how they can be sustained for a large number of cycles, that matters the most for battery applications. In this respect, there are hardly any studies that are able to tell how much of the measured capacity comes from different processes that are occurring in an electrode. The aim of this study is therefore to establish a method to understand and quantify the contributions to the reversible and irreversible capacities of silicon anodes during the initial cycle and subsequent cycles in order to develop strategies to improve the stability of the electrodes.In this paper, we report the use of an electrochemical approachdepth of discharge test -to separate the charge-discharge capacities of crystal...

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“…Figure 8 presents the first cycles of the investigation of pristine graphite and of graphite with nanostructured copper particles on the surface via cyclic voltammetry. The pristine graphite shows one irreversible cathodic peak in the region between 0.3 V and 0.6 V and the anodic and cathodic [12]. This leads to a volume expansion of up to 200% compared to only 10% volume expansion for the intercalation of unsolvated lithium ions.…”

Section: Resultsmentioning

confidence: 99%

“…One of the main reasons for exfoliation is the cointercalation of solvated lithium ions. This causes a 200% higher volume increase compared to the intercalation of unsolvated lithium ions, which leads to mechanical stress in the electrode material [12]. An often discussed phenomenon related to the topic of aging effects is the formation of the solid electrolyte interphase (SEI), a protective layer of organic and inorganic lithium salts.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Electrochemical Behavior of Nanostructured Copper Particles on Graphite for Application in Lithium Ion Batteries

Licht

Homeyer

Bösebeck

et al. 2015

Zeitschrift Für Physikalische Chemie

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Graphitic materials are currently the state-of-the-art anode materials for lithium ion secondary batteries. By chemical modification, the electrochemical performance of the pristine materials can be improved. In this paper we report on the preparation of nanostructured copper particles on graphite by thermal decomposition of copper formate. With this technique a novel, simple and low cost method for a homogeneous deposition of nanostructured copper particles on graphite was established. Different amounts of copper were realized and their influence on the electrochemical behavior of the active material was investigated.The copper particles had a size distribution between 50 nm and 300 nm. Electrochemical measurements displayed an improved performance of the synthesized composite material compared to the pristine material. Cyclic voltammetry showed a suppressed cointercalation of solvated lithium and an increased formation of the solid electrolyte interphase (SEI). Battery cycling demonstrated an increased discharge capacity and cycling stability.

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Graphites for Lithium‐Ion Cells: The Correlation of the First‐Cycle Charge Loss with the Brunauer‐Emmett‐Teller Surface Area

Cited by 325 publications

References 11 publications

An Investigation of the Effect of Graphite Degradation on Irreversible Capacity in Lithium-ion Cells

An Investigation of the Effect of Graphite Degradation on Irreversible Capacity in Lithium-ion Cells

Insights from Studying the Origins of Reversible and Irreversible Capacities on Silicon Electrodes

Synthesis and Electrochemical Behavior of Nanostructured Copper Particles on Graphite for Application in Lithium Ion Batteries

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