New insights into the structure-property relationship of high-voltage electrolyte components for lithium-ion batteries using the pKa value

Gallus, Dennis Roman; Wagner, Ralf; Wiemers‐Meyer, Simon; Winter, Martin; Cekic‐Laskovic, Isidora

doi:10.1016/j.electacta.2015.10.002

Cited by 127 publications

(103 citation statements)

References 26 publications

Supporting

Mentioning

102

Contrasting

Order By: Relevance

“…The increase in both the average discharge potential and the specific charge results in an increase of the specific energy of lab‐scale NMC111/Li half cells of ca. 50% . However, cycling above 4.6 V versus Li/Li + inevitably results in decreased cycle life .…”

Section: Introductionmentioning

confidence: 99%

“…These considerations demonstrate that battery ageing and capacity fading originate from multiple and complex failure mechanisms. In order to solve the problems associated with the unstable cathode/electrolyte interface (CEI) at high voltages, various approaches are intensively discussed in literature, including the design of electrolytes stable against oxidative decomposition, addition of CEI film‐forming electrolyte additives, HF scavengers, surface coatings, and doping of the host structure with heteroatoms …”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Counterintuitive Role of Magnesium Salts as Effective Electrolyte Additives for High Voltage Lithium‐Ion Batteries

Wagner

Streipert

Kraft

et al. 2016

Adv Materials Inter

Self Cite

View full text Add to dashboard Cite

Further development of high voltage lithium‐ion batteries requires electrolyte formulations stable against oxidation or measures to generate a protective cathode/electrolyte interface (CEI) film. In the frame of this work, the actually counterintuitive concept of using metal ions as electrolyte additives to stabilize the CEI has proven to be successful. The addition of 1 wt% magnesium bis(trifluoromethanesulfonyl)imide (Mg(TFSI)2) as electrolyte additive to a conventional LiPF6/organic carbonate electrolyte suppresses the oxidative decomposition of the bulk electrolyte as displayed in improved capacity retention, increased Coulombic efficiencies, and reduced self‐discharge of LiNi1/3Mn1/3Co1/3O2 (NMC111)/Li half cells charged to the elevated upper cutoff potential of 4.6 V versus Li/Li+ at 20 °C. Moreover, the addition of Mg(TFSI)2 shows no adverse effect on the cycling performance of graphite anodes, as observed by good long‐term cycling results of NMC111/graphite full cells. Ex situ analysis via X‐ray photoelectron spectroscopy, scanning electron microscopy, time‐of‐flight secondary ion mass spectrometry, and electron energy loss spectroscopy of the harvested NMC111 electrodes after cycling indicate that the addition of Mg2+ ions leads to the formation of a CEI layer as a result of an increased hydrolysis reaction of the PF6 – anion.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Counterintuitive Role of Magnesium Salts as Effective Electrolyte Additives for High Voltage Lithium‐Ion Batteries

Wagner

Streipert

Kraft

et al. 2016

Adv Materials Inter

Self Cite

View full text Add to dashboard Cite

show abstract

“…CO 2 and O 2 reduction). [45,46] A reliable ab initio method to calculate deprotonation free energies would provide an improvement upon existing computational approaches to determining pKa's and protonation states, [47][48][49] which would have significant ramifications for drug discovery, [50,51] materials science, [52][53][54] and the structural determination of biological complexes. [55,56] In the context of chemical catalysis, proton removal is known to be the rate-limiting step in many important reactions, e.g.…”

Section: Introductionmentioning

confidence: 99%

Chemical Transformations Approaching Chemical Accuracy via Correlated Sampling in Auxiliary-Field Quantum Monte Carlo

Shee

Zhang

Reichman

et al. 2017

J. Chem. Theory Comput.

View full text Add to dashboard Cite

The exact and phaseless variants of Auxiliary-Field Quantum Monte Carlo (AFQMC) have been shown to be capable of producing accurate ground-state energies for a wide variety of systems including those which exhibit substantial electron correlation effects. The computational cost of performing these calculations has to date been relatively high, impeding many important applications of these approaches. Here we present a correlated sampling methodology for AFQMC which relies on error cancellation to dramatically accelerate the calculation of energy differences of relevance to chemical transformations. In particular, we show that our correlated sampling-based AFQMC approach is capable of calculating redox properties, deprotonation free-energies, and hydrogen abstraction energies in an efficient manner without sacrificing accuracy. We validate the computational protocol by calculating the ionization potentials and electron affinities of the atoms contained in the G2 Test Set, and then proceed to utilize a composite method, which treats fixedgeometry processes with correlated sampling-based AFQMC and relaxation energies via MP2, to compute the ionization potential, deprotonation free-energy, and the O-H bond disocciation energy of methanol, all to within chemical accuracy. We show that the efficiency of correlated sampling relative to uncorrelated calculations increases with system and basis set size, and that correlated sampling greatly reduces the required number of random walkers to achieve a target statistical error. This translates to CPU-time speed-up factors of 55, 25, and 24 for the the ionization potential of the K atom, the deprotonation of methanol, and hydrogen abstraction from the O-H bond of methanol, respectively. We conclude with a discussion of further efficiency improvements that may open the door to the accurate description of chemical processes in complex systems.

show abstract

“…3 The generated H 2 O further promotes the hydrolysis reactions of LiPF 6 to generate HF, 4 which induces serious damage of metal oxide cathodes 5,6 and the solidelectrolyte interphase (SEI) on the graphite anodes. 7 An economic way to prevent the oxidation of the traditional electrolyte formulations at high voltage is to use specic electrolyte additives to form a cathode-electrolyte interphase (CEI), 5,8 stabilize the electrolyte salt, 9 scavenge the corrosive impurities (HF, PF 5 ), 10 or to remove the O 2 gas evolved from the cathode material.…”

Section: Introductionmentioning

confidence: 99%

Lifetime limit of tris(trimethylsilyl) phosphite as electrolyte additive for high voltage lithium ion batteries

Tao

Hahn

et al. 2016

RSC Adv.

Self Cite

View full text Add to dashboard Cite

The tris(trimethylsilyl) phosphite (TMSPi) is considered as an ideal electrolyte additive for lithium ion batteries. In this work, its positive effect as well as its failure mechanism in a LiPF 6 containing electrolyte was studied by means of selected electrochemical, structural and analytical techniques. The LiNi 0.5 Co 0.2 Mn 0.3 O 2 /graphite cells with TMSPi as electrolyte additive were cycled between 2.8 and 4.6 V.Thanks to the compact cathode electrolyte interphase formed by the oxidative decomposition of TMSPi in a freshly prepared TMSPi containing electrolyte, both the discharge capacity and the cycling stability of cells were enhanced. However, our results also show that TMSPi actually reacts with LiPF 6 at room temperature. TMSPi is consumed by this spontaneous reaction after aging for certain time. In addition, a part of the fluorophosphates, generated from the hydrolysis of LiPF 6 , is bonded to one or two TMS groups, causing a decrease in the fluorophosphate content in the CEI film. Consequently, the cycling stability of the lithium ion cells with aged TMSPi containing electrolyte deteriorates. The obtained results offer important insights into the practical application of TMSPi, which means that TMSPi can only be used as an effective additive in a freshly prepared LiPF 6 containing electrolyte.

show abstract

New insights into the structure-property relationship of high-voltage electrolyte components for lithium-ion batteries using the pKa value

Cited by 127 publications

References 26 publications

Counterintuitive Role of Magnesium Salts as Effective Electrolyte Additives for High Voltage Lithium‐Ion Batteries

Counterintuitive Role of Magnesium Salts as Effective Electrolyte Additives for High Voltage Lithium‐Ion Batteries

Chemical Transformations Approaching Chemical Accuracy via Correlated Sampling in Auxiliary-Field Quantum Monte Carlo

Lifetime limit of tris(trimethylsilyl) phosphite as electrolyte additive for high voltage lithium ion batteries

Contact Info

Product

Resources

About