Lithium‐Ionen‐Technologie und was danach kommen könnte

Bieker, Peter; Winter, Martin

doi:10.1002/ciuz.201600745

Cited by 53 publications

(27 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Most of the known electrolyte salts contain fluorinated anions and are generally highly soluble in dipolar aprotic solvents because of the delocalized charge of the anion as well as the electronwithdrawing properties of fluorine atoms. [19] However,l ithium fluoride (LiF) is an exception and can often be found as as olid deposit on the surface of the electrodes.F luorine atoms,p resent in the form of anions in the electrolyte formulation, play as ignificant role in LIBs and LMBs.A s components of the formed SEI and/or CEI, [20] they may decrease the surface tension of the electrolyte,e nhance the wettability of composite electrodes and porous separators when present in the dissolved fluorinated form, [21] and may be identified as components of the passivation film formed on aluminum current collectors. [22] Thelithium cation of the conducting salt has asmall ionic radius and ahigh charge density;thus,itisweakly polarizable and is,t herefore,d efined as ah ard Lewis acid.…”

Section: Fluorinated Electrolytesmentioning

confidence: 99%

“…When the concentration of the conducting salt in an electrolyte is raised, the number of charge carriers and the viscosity increases and, as an inevitable consequence,t he ion mobility will decrease.T his competition between the increase in the number of charge carriers and the decrease in their mobility leads to amaximum in the conductivity-concentration relationship. [19] Thed etermination of this conductivity maximum is of significant importance for battery applications and is often observed at ac oncentration of about 1m in electrolytes based on organic solvents. [12a] Lithium tetrafluoroborate (LiBF 4 )d isplays certain advantages as aconducting salt compared to LiPF 6 ,such as better thermal stability,l ower sensitivity toward environmental moisture,a nd al ower charge-transfer resistance, especially at low temperatures.…”

Section: Transport Properties:viscosity and Conductivitymentioning

confidence: 99%

See 1 more Smart Citation

Fluorine and Lithium: Ideal Partners for High‐Performance Rechargeable Battery Electrolytes

et al. 2019

View full text Add to dashboard Cite

Further enhancement in the energy densities of rechargeable lithium batteries calls for novel cell chemistry with advanced electrode materials that are compatible with suitable electrolytes without compromising the overall performance and safety, especially when considering high‐voltage applications. Significant advancements in cell chemistry based on traditional organic carbonate‐based electrolytes may be successfully achieved by introducing fluorine into the salt, solvent/cosolvent, or functional additive structure. The combination of the benefits from different constituents enables optimization of the electrolyte and battery chemistry toward specific, targeted applications. This Review aims to highlight key research activities and technical developments of fluorine‐based materials for aprotic non‐aqueous solvent‐based electrolytes and their components along with the related ongoing scientific challenges and limitations. Ionic liquid‐based electrolytes containing fluorine will not be considered in this Review.

show abstract

Section: Fluorinated Electrolytesmentioning

confidence: 99%

Section: Transport Properties:viscosity and Conductivitymentioning

confidence: 99%

Fluorine and Lithium: Ideal Partners for High‐Performance Rechargeable Battery Electrolytes

et al. 2019

View full text Add to dashboard Cite

show abstract

“…With the emergence of new application markets demanding a higher energy density, battery systems with cathode active materials being oxygen, sulfur, or fluoride and with lithium metal as the anode material are reconsidered as viable options . Although the lithium‐metal anode has the advantages of both high gravimetric and volumetric capacities (3862 Ah kg −1 and 2085 Ah L −1 ) and is already successfully used in primary batteries, it is still plagued by a series of issues that limit its successful operation in rechargeable applications, when organic solvent based electrolytes are used .…”

Section: Introductionmentioning

confidence: 99%

Lithium‐Metal Foil Surface Modification: An Effective Method to Improve the Cycling Performance of Lithium‐Metal Batteries

Becking¹,

Gröbmeyer²,

Kolek³

et al. 2017

Adv Materials Inter

Self Cite

167

160

View full text Add to dashboard Cite

Although the lithium-metal anode has the advantages of both high gravimetric and volumetric capacities (3862 Ah kg −1 and 2085 Ah L −1 ) [13] and is already successfully used in primary batteries, it is still plagued by a series of issues that limit its successful operation in rechargeable applications, when organic solvent based electrolytes are used. [14] One of them is the nature of the lithium-metal dissolution and redeposition in the discharge and charge process together with the composition of the solid electrolyte interphase (SEI) [15,16] that is formed immediately after electrolyte addition and continues to form, grow and alter during cycling, [17] which limits the rechargeability in these battery systems and decreases their safety. [15,18,19] The SEI, though not being a homo geneous single phase, varies in composition and thickness and these differences lead to inhomogeneous and thus locally different current densities during the discharge and charge process, which can ultimately cause the formation of high surface area lithium (HSAL) during lithium deposition (charging) and hole/pit formation during dissolution (discharging). [20][21][22] In the worst case, the HSAL morphology takes the form of dendrites, i.e., small needle like lithium deposits that can grow through the separator from the anode towards the cathode. This process can lead to an internal short circuit of the cell resulting in local overheating and possibly cause a cell fire due to an increased reactivity with the electrolyte and the low melting point of lithium (180.54 °C). [23] Practical approaches to improve the rechargeable lithiummetal anode from the electrode material's point of view concentrate on either using coated lithium powder [24,25] or foil [26] and lithium with surface micropatterning. [27,28] The main underlying principle is increasing the specific surface area thus decreasing the effective current density and the resulting overpotential. However, the behavior of the lithium-metal electrode is quite complex and electrolyte-dependent [22,[29][30][31] and there is a need to identify the optimal conditions under which lithium-metal electrodes can cycle with both an increased reversibility and low overpotentials. [32] As-received lithium-metal foil contains several contaminants, [33] particularly on the surface. [34] In addition, even a new lithium foil that is considered to be smooth shows a non-negligible surface roughness that Lithium metal as an electrode material possesses a native surface film, which leads to a rough surface and this has a negative impact on the cycling behavior. A simple, fast, and reproducible technique is shown, which makes it possible to flatten and thin the native surface film of the lithium-metal anode. Atomic force microscopy and scanning electron microscopy images are presented to verify the success of the method and X-ray photoelectron spectroscopy measurements reveal that the chemical composition of the lithium surface is also changed. Furthermore, galvanostatic measurements indicate superior c...

show abstract

“…Metallisches Lithium hat sich in den letzten Jahren als vielversprechendes Anodenmaterial für wiederaufladbare Batterien mit hoher Energiedichte herausgestellt . Doch Probleme bereiten oftmals Dendrite – rankenartige Lithiumkristalle, die durch wiederholtes Laden‐ und Entladen der Akkus entstehen.…”

Section: Abbunclassified

Zutat für sichere Akkus: Nanodiamanten

Frerichs¹

2018

Chemie in nserer Zeit

View full text Add to dashboard Cite

show abstract

Lithium‐Ionen‐Technologie und was danach kommen könnte

Cited by 53 publications

References 27 publications

Fluorine and Lithium: Ideal Partners for High‐Performance Rechargeable Battery Electrolytes

Fluorine and Lithium: Ideal Partners for High‐Performance Rechargeable Battery Electrolytes

Lithium‐Metal Foil Surface Modification: An Effective Method to Improve the Cycling Performance of Lithium‐Metal Batteries

Zutat für sichere Akkus: Nanodiamanten

Contact Info

Product

Resources

About