Temperature-Robust Solvation Enabled by Solvent Interactions for Low-Temperature Sodium Metal Batteries

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Янв. 28, 2025

The broad temperature adaptability associated with the desolvation process remains a formidable challenge for organic electrolytes in rechargeable metal batteries, especially under low-temperature (LT) conditions. Although traditional approach involves utilizing high degree of anion participation solvation structure, known as weakly (WSEs), structure these is highly susceptible to fluctuations, potentially undermining their LT performance. To address this limitation, we have devised an innovative electrolyte that harnesses interplay between solvent molecules, effectively blending strong and weak solvents while incorporating mostly unchanged by variations. Remarkably, competitive coordination two molecules introduces local disorder, which not only boosts ionic conductivity but also prevents salt precipitation solidification. Therefore, has 3.12 mS cm-1 at -40 °C. Na3V2(PO4)3||Na cells demonstrated reversible capacity 95.9 mAh g-1 °C, 87.6% room temperature, well stable cycling 3400 cycles retention 98.2% -20 °C 5 C 600 96.1% 1 C. This study provides new perspective on designing regulating temperature-robust structures.

Язык: Английский

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Improving Low‐Temperature Tolerance of a Lithium‐Ion Battery by a Localized High‐Concentration Electrolyte Based on the Weak Solvation Effect

Battery energy, Год журнала: 2025, Номер unknown

Опубликована: Янв. 30, 2025

ABSTRACT Due to the strong affinity between solvent and Li + , desolvation process of at interface as a rate‐controlling step slows down, which greatly reduces low‐temperature electrochemical performance lithium‐ion batteries (LIBs) thus limits its wide application in energy storage. Herein, improve tolerance, localized high‐concentration electrolyte based on weak solvation (Wb‐LHCE) has been designed by adding diluent hexafluorobenzene (FB) solvating tetrahydrofuran (THF). Combining theoretical calculations with characterization tests, it is found that addition FB, dipole–dipole interaction causes FB compete for THF. This competition move away from weakening binding THF, whereas anions are transported into shell forming an anion‐rich structure. In accelerating process, this unique structure optimizes composition CEI film, making thin, dense, homogeneous, rich inorganic components, improving interfacial stability battery. As result, assembled LiFePO 4 /Li half‐cell shows excellent performances low temperature. That is, can maintain high discharge specific capacity 124.2 mAh g −1 after 100 cycles rate 0.2C −20°C. provides attractive avenue design advanced electrolytes improvement battery tolerance harsh conditions.

Язык: Английский

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Solvation chemistry in liquid electrolytes for rechargeable lithium batteries at low temperatures

EcoEnergy, Год журнала: 2025, Номер unknown

Опубликована: Фев. 12, 2025

Abstract Over the past few decades, significant advancements have been made in development of low‐temperature liquid electrolytes for lithium batteries (LBs). Ongoing exploration is crucial further enhancing performance these batteries. Solvation chemistry plays a dominant role determining properties electrolyte, significantly affecting LBs at low temperatures (LTs). This review introduces solvation structures and their impact, discussing how promote fast desolvation processes contribute to improvement battery performance. Additionally, various solvent strategies are highlighted refine LTs, including use linear cyclic ethers/esters, as well functional groups within solvents. The also summarizes impact salts containing organic/inorganic anions on chemistry. Characterization techniques discussed, providing comprehensive analysis that offers valuable insights developing next‐generation ensure reliable across wide temperature range.

Язык: Английский

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Molecular Insights into Anion-Specific Freezing Point Depression in Lithium Salt Solutions

The Journal of Physical Chemistry B, Год журнала: 2025, Номер unknown

Опубликована: Фев. 26, 2025

The depression of freezing points in electrolyte aqueous solutions, a well-known colligative property, is traditionally attributed to entropy increases arising from ion-induced disruption the hydrogen-bonding networks. However, microscopic mechanisms governing this phenomenon remain poorly understood, particularly at concentrated salt concentrations where ion-specific effects emerge. In study, we combined Raman spectroscopy, molecular dynamics (MD) simulations, and density functional theory (DFT) calculations investigate structures water lithium solutions containing typical anions. MD simulations reveal that diffusion barriers are influenced by anion identity, while DFT indicate anions with lower surface electrostatic potentials weaken network caused cation. By systematically evaluating five salts─LiClO4, LiNO3, LiBF4, LiCl, LiTFSI─we show point arises complex interplay anion–water, cation–anion, cation–water interactions. Notably, trends deviate Hofmeister series, suggesting critical role ion-pairing aggregate formation determining solution behavior. Our results further rather than intrinsic structure─disrupting ability anions, mobility molecules within ions' hydration shells primary determinant behavior, challenging conventional view revealing influence local on solid/liquid transitions. These findings provide molecular-level insights into implications for lithium-ion battery electrolytes other ionic systems.

Язык: Английский

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Electrolyte Chemistry Modulation Toward High‐Performance and Ultralow‐Temperature Silicon Anode

Advanced Materials, Год журнала: 2025, Номер unknown

Опубликована: Март 2, 2025

Abstract The high‐capacity silicon (Si) anode usually suffers from rapid capacity decay and low Coulombic efficiency in carbonate electrolytes resulting large volume expansion unstable solid electrolyte interphase (SEI). In addition, the sluggish electrode kinetics routine at subzero temperatures severely hampers operational capabilities of Si‐based batteries. Herein, a rational design strategy is reported to tune solvation chemistry interfacial behavior for high‐performance Si anode. stability electrochemical reaction can be enhanced simultaneously both room temperature ultralow by combining two kinds ether‐based solvents (cyclopentylmethyl ether tetrahydrofuran), which enables high cation conductivity, Li‐ion desolvation barrier, formation robust LiF‐elastic polymer SEI. Consequently, optimized extends cyclability anode, maintaining more than 80% retention over 200 cycles −20 −35 °C. Even −40 °C, still delivers reversible 2157.0 mAh g −1 , showing highest 68.5% up date relative its room‐temperature capacity. Moreover, assembled full cells Si||LiFePO 4 Si||LiNi 0.8 Co 0.1 Mn O 2 demonstrate excellent performance with no degradation 180 120 cycles, respectively,

Язык: Английский

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