XRD study of phase transformations in lithiated graphite anodes by Rietveld method

Missyul, Alexander; Bolshakov, Ivan A.; Shpanchenko, Roman V.

doi:10.1017/s0885715617000458

Cited by 64 publications

(67 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The similarity between the stages observed during Gr lithiation and delithiation is consistent with the well‐known reversible nature of Li + ion intercalation into Gr . As lithiation progresses the sequential formation of dilute stage I (denoted I'), stage IV/III, stage IIL, stage II, and stage I has been reported . Of these stages, the stoichiometry of stages II and I has been determined as LiC 12 and LiC 6 ; ambiguity exists as to the exact stoichiometry of the other three stages.…”

supporting

confidence: 71%

“…The spectra were collected in the 0.8–5 Å d ‐spacing range. However, given that the strongest Bragg peaks belonging to the (00l) family of planes of Li–Gr intercalates occur between 3.2 and 3.8 Å, only this range is shown. No peaks were observed from crystalline phases of Si.…”

mentioning

confidence: 99%

“…This systematic error is attributed to significant uncertainty in the crystallography of stage IIL. As acknowledged in the work of Missyul et al, from which the scattering factor of LiC 18 is obtained, it is impossible to obtain a well‐isolated LiC 18 (stage IIL) phase given the overlap of dQ/dV for LiC 30 → LiC 18 and LiC 18 → LiC 12 . This observation is confirmed in Figure b,d where stage IIL is tightly sandwiched between stages IV/III and II.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Operando Quantification of (De)Lithiation Behavior of Silicon–Graphite Blended Electrodes for Lithium‐Ion Batteries

Yao

Okasinski

Kalaga

et al. 2019

Advanced Energy Materials

145

103

View full text Add to dashboard Cite

to an unstable solid electrolyte interphase (SEI) [4][5][6][7] and large volumetric changes that lead to particle pulverization and loss of electrical contact between the active particles and the current collector. [8][9][10][11][12] Several approaches are being pursued to address these challenges, which include the following: electrolyte additives to improve SEI integrity, [5,7] electrode binders with enhanced mechanical [13] and chemical properties, [6] morphological engineering of Si particles (nanowires, nanotubes, porous particles, nanospheres, etc.), [12,14] limited-capacity cycling to limit volume expansion of the Si particles, [8,15] and developing electrodes that contain blends of Si and Gr materials. [3,7,11] The latter approach, coupled with SEI modifying additives such as fluoroethylene carbonate (FEC), has markedly improved electrode cycling performance compared to that of pure Si electrodes. [3,7,16] The potentials and kinetics for Li insertion and extraction from Si and Gr are known to be different. During electrochemical cycling of cells with a Li metal electrode ("half cells"), Si is active in the entire voltage range of 0-1.0 V, whereas Gr is active mainly below ≈0.25 V versus Li/Li + (abbreviated as V Li ). [3,8,15] The relative lithiation/delithiation behavior of the Si and Gr components in blended electrodes is not well understood. Knowledge of Li distribution between the two active components is important as it determines the volume change of the electrode during electrochemical cycling (mainly due to Si particle expansion). One reason for the knowledge gap is the amorphization of crystalline Si that occurs during lithium insertion, which makes it difficult to track the evolution of the component by conventional techniques such as X-ray diffraction (XRD).In this study, operando energy dispersive XRD is used to quantify Li content of Gr in a 15 wt% Si-Gr composite electrode. In parallel, data obtained from operando studies on a Gr-only electrode are used to calibrate behavior of the Gr component in the blended electrode. By combining the knowledge of Gr lithiation with information on the coulometric capacity for the same cell obtained from electrochemistry, the Li content of the Si component can be inferred, and the fractional lithiation of each component is obtained. The knowledge gained from our study can be used to optimize the Si and Gr contents in the blended electrode, as well as to select cutoff capacities in limited-capacity schemes, which aim to limit electrode expansion by limiting expansion of the Si component. Additional Due to the high lithium capacity of silicon, the composite (blended) electrodes containing silicon (Si) and graphite (Gr) particles are attractive alternatives to the all-Gr electrodes used in conventional lithium-ion batteries. In this Communication, the lithiation and delithiation in the Si and Gr particles in a 15 wt% Si composite electrode is quantified for each component using energy dispersive X-ray diffraction. This quantification is important as the compon...

show abstract

supporting

confidence: 71%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Operando Quantification of (De)Lithiation Behavior of Silicon–Graphite Blended Electrodes for Lithium‐Ion Batteries

Yao

Okasinski

Kalaga

et al. 2019

Advanced Energy Materials

145

103

View full text Add to dashboard Cite

show abstract

“…Regarding the space group of the intermediate phases, there seems to be an agreement in the literature that LiC 12 crystallizes in P6/mmm with AAAA-type stacking (Imai & Watanabe, 2007;Woo et al, 1983;Guerard & Herold, 1975;Billaud et al, 1996). The diluted stage II compound LiC 18 is reported to have a stacking sequence of AABB (Woo et al, 1983;Billaud et al, 1996), with the suggested space group P6 3 mc (Missyul et al, 2017). As for the stage III compound, the stacking sequence was suggested to be AABAACAA or AABAABAA (Billaud et al, 1996;Billaud & Henry, 2002).…”

Section: Introductionmentioning

confidence: 53%

Intercalation of lithium into disordered graphite in a working battery

Johnsen¹,

Norby²,

Leoni³

2018

J Appl Crystallogr

View full text Add to dashboard Cite

The structural transformations occurring during the intercalation of lithium into disordered graphite in a working battery were studied in detail by operando X-ray powder diffraction (XRPD). By using a capillary-based micro-battery cell, it was possible to study the stacking disorder in the initial graphite as well as in lithiated graphites. The micro-battery cell was assembled in its charged state with graphite as positive electrode and metallic lithium as counter electrode. The battery was discharged until a stage II compound (LiC 12 ) was formed. The operando XRPD data reveal that the graphitic electrode material retains a disordered nature during the intercalation process. A DIFFaX+ refinement based on the initial operando XRPD pattern shows that the initial graphite generally has an intergrown structure with domains of graphite 2H and graphite 3R. However, the average stacking sequence of the initial graphite also contains a significant concentration of AA-type stacking of the graphene sheets. DIFFaX+ was further used to refine structure models of a stage III type compound and the final stage II compound. The refinement of the stage II compound showed that it is dominated by AAAA-type stacking, but that it also contains a significant concentration of AABB-type slabs in the average stacking sequence.

show abstract

“…Through literature review, five main stages are identified and deconvoluted from the spectra collected using their reported d-spacing ranges: dilute stage I (denoted I 0 ), stage IV/III, stage IIL, stage II, and stage I. [26][27][28][29] The following equation is used to estimate the average lithium content x of each layer (expressed in Li atoms per C 6 ):…”

Section: Energy Dispersive X-ray Diffraction (Edxrd)mentioning

confidence: 99%

Quantifying lithium concentration gradients in the graphite electrode of Li-ion cells using operando energy dispersive X-ray diffraction

Yao

Okasinski

Kalaga

et al. 2019

Energy Environ. Sci.

147

135

View full text Add to dashboard Cite

show abstract

XRD study of phase transformations in lithiated graphite anodes by Rietveld method

Cited by 64 publications

References 24 publications

Operando Quantification of (De)Lithiation Behavior of Silicon–Graphite Blended Electrodes for Lithium‐Ion Batteries

Operando Quantification of (De)Lithiation Behavior of Silicon–Graphite Blended Electrodes for Lithium‐Ion Batteries

Intercalation of lithium into disordered graphite in a working battery

Quantifying lithium concentration gradients in the graphite electrode of Li-ion cells using operando energy dispersive X-ray diffraction

Contact Info

Product

Resources

About