Significantly improved cycling performance of LiCoPO4 cathodes

Sharabi, Ronit; Markevich, Elena; Borgel, Valentina; Salitra, Gregory; Aurbach, Doron; Semrau, G.; Schmidt, Michael A.; Schall, N.; Stinner, Christoph

doi:10.1016/j.elecom.2011.05.006

Cited by 68 publications

(41 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…17,41 Even though POF 3 and CO 2 also evolve with a PP separator, marked differences exist in the onset potentials and evolution rates compared to the glass fiber separator based cell. The effective contact area between separator and conductive carbon can be assumed to be substantially higher for the glass fiber compared to the PP separator.…”

Section: Resultsmentioning

confidence: 99%

Decomposition of LiPF₆in High Energy Lithium-Ion Batteries Studied with Online Electrochemical Mass Spectrometry

Guéguen

Streich

et al. 2016

J. Electrochem. Soc.

214

169

View full text Add to dashboard Cite

The chemical and electrochemical instabilities of LiPF 6 in carbonate electrolytes for Li-ion batteries were studied with online electrochemical mass spectrometry (OEMS). Decomposition of carbonate electrolytes based on LiPF 6 eventually results in the formation of POF 3 , which is readily detected and followed in situ during operation of Li-rich HE-NCM-based Li-ion cells. Electrode potentials above ∼4.2 V leads to carbonate solvent oxidation and presumably the formation of ROH species, which subsequently hydrolyze the LiPF 6 salt and initiate a thermally activated autocatalytic electrolyte decomposition cycle involving POF 3 as a reactive intermediate. Activation of the Li 2 MnO 3 domains of the Li-rich cathode contributes along with electrolyte and separator impurities to further POF 3 generation. Electrode potentials below ∼2.5 V vs. Li + /Li impede POF 3 formation and presumably also further electrolyte decomposition by scavenging reactive intermediate species. As a result, much less POF 3 gas was detected upon the 2 nd charge when using Li metal counter electrode, contrary to delithiated LiFePO 4 . In situ OEMS confirm that the parasitic reactions involving LiPF 6 constitute an intricate reaction scheme, but more importantly, provide further evidence about what the components of this scheme are and how these may interact with each other. Rechargeable Li-ion batteries are nowadays extensively used to power electronics and are entering the transportation sector by powering electric vehicles (EV). A wide range of both negative (e.g. graphite) and positive electrode materials (e.g. layered cobalt oxides, spinel-type manganese oxides, and olivine-type iron phosphates) have been thoroughly investigated and are now in widespread use in commercial batteries. The specific energy of Li-ion batteries is limited mainly by the positive electrode materials, having typical practical specific charges of ∼150 mAh/g and average operating potentials of ∼3.8 V vs. Li + /Li, which significantly inhibits the introduction of Li-ion batteries as power source in new applications. In recent years, the layered Li-rich cobalt-nickel-manganese oxides xLi 2 MnO 3 (1−x)(LiMO 2 ) (x ∼ 0.5, M = Co, Ni, Mn), hereafter called HE-NCM, have been shown to exhibit a high and reversible specific charge (∼250 mAh/g) and a competitive average operating potential (∼3.75 V vs. Li + /Li). [1][2][3][4] The origin of such a high specific charge is not yet completely understood, as the exact structure of the HE-NCM materials is highly dependent on the synthesis conditions and models coming from structural characterization are still under debate. Several reports have shown the presence of so-called Li 2 MnO 3 domains in the compound 5,6 whereas other groups demonstrated the monophasic character of their materials.7 However, during the first charge, a long potential plateau at ∼4.5 V vs. Li + /Li, not observed for conventional layered oxides, results from the delithiation process of the Li 2 MnO 3 domains accompanied by oxygen extraction. The extracted oxy...

show abstract

Section: Resultsmentioning

confidence: 99%

Decomposition of LiPF₆in High Energy Lithium-Ion Batteries Studied with Online Electrochemical Mass Spectrometry

Guéguen

Streich

et al. 2016

J. Electrochem. Soc.

214

169

View full text Add to dashboard Cite

show abstract

“…Since LiCoPO 4 always presented poor cyclic stability due to the electrolyte decomposition at high potentials and its intrinsic properties, such as the low electronic conductivity and structural instability during Li deintercalation [32,33], even though various modified strategies were employed [13,[32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51]. The effect of LiDFOB on high-voltage cathode materials can be disclosed distinctly in this system.…”

Section: Introductionmentioning

confidence: 96%

Effect of lithium difluoro(oxalate)borate (LiDFOB) additive on the performance of high-voltage lithium-ion batteries

Wei

Xing

et al. 2012

J Appl Electrochem

View full text Add to dashboard Cite

Lithium difluoro(oxalato)borate (LiDFOB) was investigated as an electrolyte additive for high-voltage lithium-ion batteries in order to decrease the decomposition of the electrolyte. As a typical high-voltage cathode material, LiCoPO 4 was tested in the LiDFOB-containing electrolyte, exhibiting higher reversible charge/discharge capacity and better cyclic stability. The effect of LiDFOB on the formation of a stable interphase film was investigated through cyclic voltammetry and X-ray photoelectron spectroscopy. LiDFOB was helpful to form a stable interphase film and passivate the cathode surface; therefore, the decomposition of the electrolyte was inhibited accordingly.

show abstract

“…3-4) and amorphous carbon respectively [25][26]. The ratio of the calculated peak intensities (I D /I G ) demonstrates that amorphous carbon is dominant, which could favor lithium intercalation.…”

Section: Conductivity Studiesmentioning

confidence: 99%

Carbonate anion controlled growth of LiCoPO4/C nanorods and its improved electrochemical behavior

Gangulibabu

Kalaiselvi

Meyrick

et al. 2013

Electrochimica Acta

View full text Add to dashboard Cite

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. Heating the carbonate rich precursor in an inert atmosphere produces a Co 2 P phase that is conductive. Addition of super P carbon resulted in an amorphous carbon coating on LiCoPO 4 particles. LiCoPO 4 /C nanorods with a co-existence of Co 2 P exhibit excellent discharge capacity with retention on multiple cycling. AbstractLiCoPO 4 /C nanocomposite with growth controlled by carbonate anions was synthesized via a unique solid-state fusion method. Carbonate anions in the form of H 2 CO 3 or a mixture of H 2 CO 3 + (NH 4 ) 2 CO 3 have been used as a growth inhibiting modifier to produce morphology controlled lithium cobalt phosphate. The presence of cobalt phosphide (Co 2 P) as a second phase improved the conductivity and electrochemical properties of the parent LiCoPO 4. The formation of Co 2 P is found to be achievable only in

show abstract

Significantly improved cycling performance of LiCoPO4 cathodes

Cited by 68 publications

References 8 publications

Decomposition of LiPF₆in High Energy Lithium-Ion Batteries Studied with Online Electrochemical Mass Spectrometry

Decomposition of LiPF₆in High Energy Lithium-Ion Batteries Studied with Online Electrochemical Mass Spectrometry

Effect of lithium difluoro(oxalate)borate (LiDFOB) additive on the performance of high-voltage lithium-ion batteries

Carbonate anion controlled growth of LiCoPO4/C nanorods and its improved electrochemical behavior

Contact Info

Product

Resources

About

Significantly improved cycling performance of LiCoPO4 cathodes

Cited by 68 publications

References 8 publications

Decomposition of LiPF6in High Energy Lithium-Ion Batteries Studied with Online Electrochemical Mass Spectrometry

Decomposition of LiPF6in High Energy Lithium-Ion Batteries Studied with Online Electrochemical Mass Spectrometry

Effect of lithium difluoro(oxalate)borate (LiDFOB) additive on the performance of high-voltage lithium-ion batteries

Carbonate anion controlled growth of LiCoPO4/C nanorods and its improved electrochemical behavior

Contact Info

Product

Resources

About

Decomposition of LiPF₆in High Energy Lithium-Ion Batteries Studied with Online Electrochemical Mass Spectrometry

Decomposition of LiPF₆in High Energy Lithium-Ion Batteries Studied with Online Electrochemical Mass Spectrometry