An Aggregate Cluster‐Dispersed Electrolyte Guides the Uniform Nucleation and Growth of Lithium at Lithium Metal Anodes

Lee, Min-Suk; Roev, Victor; Jung, Chang Won; Kim, Ji-Rae; Han, Sangil; Kang, Hee-Cheol; Im, Dongmin; Kim, Il-Seok

doi:10.1002/slct.201800757

Cited by 11 publications

(10 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It was thought that ether-based electrolytes were incompatible with high-voltage (>4 V vs Li + /Li) cathodes due to poor stability against oxidation . The surprising discovery of high oxidation stability (4.5 V vs Li + /Li) of equimolar LiTFSI–triglyme or LiTFSI–tetraglyme opened up opportunities for new electrolyte designs for high-voltage LMBs. , More recently, various ether-based low-concentration electrolytes, − high-concentration electrolytes (HCEs), − and localized high-concentration electrolytes (LHCEs) − were developed. The combination of lithium bis(fluorosulfonyl)imide (LiFSI) and 1,2-dimethoxyethane (DME) was one of the most common electrolytes due to commercial availability, high salt solubility, good Li CE, dendrite suppression, and high ionic conductivity.…”

Section: Introductionmentioning

confidence: 99%

Steric Effect Tuned Ion Solvation Enabling Stable Cycling of High-Voltage Lithium Metal Battery

et al. 2021

View full text Add to dashboard Cite

1,2-Dimethoxyethane (DME) is a common electrolyte solvent for lithium metal batteries. Various DME-based electrolyte designs have improved long-term cyclability of high-voltage full cells. However, insufficient Coulombic efficiency at the Li anode and poor high-voltage stability remain a challenge for DME electrolytes. Here, we report a molecular design principle that utilizes a steric hindrance effect to tune the solvation structures of Li+ ions. We hypothesized that by substituting the methoxy groups on DME with larger-sized ethoxy groups, the resulting 1,2-diethoxyethane (DEE) should have a weaker solvation ability and consequently more anion-rich inner solvation shells, both of which enhance interfacial stability at the cathode and anode. Experimental and computational evidence indicates such steric-effect-based design leads to an appreciable improvement in electrochemical stability of lithium bis(fluorosulfonyl)imide (LiFSI)/DEE electrolytes. Under stringent full-cell conditions of 4.8 mAh cm–2 NMC811, 50 μm thin Li, and high cutoff voltage at 4.4 V, 4 M LiFSI/DEE enabled 182 cycles until 80% capacity retention while 4 M LiFSI/DME only achieved 94 cycles. This work points out a promising path toward the molecular design of non-fluorinated ether-based electrolyte solvents for practical high-voltage Li metal batteries.

show abstract

Section: Introductionmentioning

confidence: 99%

Steric Effect Tuned Ion Solvation Enabling Stable Cycling of High-Voltage Lithium Metal Battery

et al. 2021

View full text Add to dashboard Cite

show abstract

“…22 Similar concepts have also been used by several other groups to improve the performance of LMBs and LIBs. 21,[35][36][37] Here, we give a brief review on the LHCEs we developed recently that are highly stable with both LMAs and high-voltage cathodes such as Ni-rich LiNi x Co y Mn 1-x-y O 2 (NMC) (x ⩾ 0.6) and LiCoO 2 . These LHCEs exhibit not just the advantages of highly concentrated electrolytes, but also low viscosity, and low cost of the low-concentration electrolytes.…”

mentioning

confidence: 99%

Review—Localized High-Concentration Electrolytes for Lithium Batteries

Cao

Jia

et al. 2021

J. Electrochem. Soc.

372

338

View full text Add to dashboard Cite

The conventional LiPF6/carbonate-based electrolytes have been widely used in graphite (Gr)-based lithium (Li) ion batteries (LIBs) for more than 30 years because a stable solid electrolyte interphase (SEI) layer forms on the graphite surface and enables its long-term cycling stability. However, few of these electrolytes are stable under the more stringent conditions needed with a Li metal anode (LMA) and other anodes, such as silicon (Si), which exhibit large volume changes during charge/discharge processes. Many different approaches have been developed lately to stabilize Li metal batteries (LMBs) and Si-based LIBs. From this aspect, localized high-concentration electrolytes (LHCEs) have unique advantages: not only are they stable in a wide electrochemical window, they can also form stable SEI layers on LMA and Si anode surfaces to enable their long-term cycling stability. The ultrathin SEI layer formed on a Gr anode can also improve the safety and high-rate operation of conventional LIBs. In this paper, we give a brief summary of our recent work on LHCEs, including their design principle and applications in both LMBs and LIBs. A perspective on the future development of LHCEs is also discussed.

show abstract

“…Herein, we introduce a new generation of LHCEs tailored for Si anodes using 1 H ,1 H ,5 H -octafluoropentyl 1,1,2,2-tetrafluoroethyl ether (OTE) as a diluent, which has a high boiling point of 133 °C. While several studies of OTE as a promising solvent have been reported for improving the cycling stability of Li–S, , Li–metal, and Li–air batteries, further investigation of utilizing OTE as a diluent is necessary for intercalation and alloying type anodes, such as graphite and Si. Electrolyte properties such as salt concentration and solvent-to-diluent ratio were tuned for optimized electrolyte physicochemical properties, ion coordination structure, and electrochemical performance.…”

mentioning

confidence: 99%

Rational Design of Electrolytes for Long-Term Cycling of Si Anodes over a Wide Temperature Range

et al. 2021

View full text Add to dashboard Cite

A silicon (Si) anode is a high-capacity alternative for carbonaceous anodes in lithium ion batteries. However, a large volume change during cycling and continuous side reactions with the electrolyte significantly limit its applications. We designed a localized highconcentration electrolyte using 1H,1H,5H-octafluoropentyl 1,1,2,2-tetrafluoroethyl ether (OTE) as a diluent with the desired molecular structure tailored for a Si anode operating over a wide temperature range. This electrolyte exhibits an optimized ion solvation structure and enabled better cycling stability of Si anodes over a wide temperature range. Full cells with Si/graphite composite anodes and LiNi 0.5 Mn 0.3 Co 0.2 O 2 cathodes retained 80% of their capacity after 500 cycles in 1.74 M lithium bis(fluorosulfonyl)imide in dimethyl carbonate with OTE (0.51:0.84:0.84) with enhanced thermal stability. A Si anode cycled in the new electrolyte exhibits a much thinner solid electrolyte interphase and a well-preserved dense structure. The electrolyte design principle developed in this work can be used to extend the cycle life of other high-capacity electrode materials with large volume changes.

show abstract

An Aggregate Cluster‐Dispersed Electrolyte Guides the Uniform Nucleation and Growth of Lithium at Lithium Metal Anodes

Cited by 11 publications

References 39 publications

Steric Effect Tuned Ion Solvation Enabling Stable Cycling of High-Voltage Lithium Metal Battery

Steric Effect Tuned Ion Solvation Enabling Stable Cycling of High-Voltage Lithium Metal Battery

Review—Localized High-Concentration Electrolytes for Lithium Batteries

Rational Design of Electrolytes for Long-Term Cycling of Si Anodes over a Wide Temperature Range

Contact Info

Product

Resources

About