Electrolyte Engineering for High-Performance Lithium Battery Applications

Electrolyte engineering lies at the heart of efforts to extend the energy density, cycle life and safety of lithium batteries. By tailoring salt selection, solvent composition, concentration and additive chemistry, researchers modulate ionic conductivity, electrochemical stability windows and interfacial reactions. High‐concentration and superconcentrated formulations have revealed unique solvation networks that suppress transition‐metal dissolution at high voltages and stabilise aluminium current collectors. Fluorinated solvents and weakly solvating media promote robust anion‐derived interphases, enabling compact lithium deposits and anode‐free cell designs with energy densities approaching 400 Wh kg−1. Solid polymer electrolytes based on polyethylene oxide and amide chemistries offer routes to all‐solid‐state and lithium‐metal configurations, although controlling dendrite penetration and oxidative stability remains challenging. Across liquid, gel and solid‐state systems, advances in characterising solvation structures, ion pairing and interfacial reaction products have driven a unified understanding of how bulk and interphase chemistries govern rate capability, Coulombic efficiency and thermal resilience. These insights underpin practical strategies for next‐generation cells in electric vehicles, grid storage and portable electronics.

Research from Nature Portfolio

Recent studies have introduced an optimally fluorinated ester coupled with weakly solvating fluoroethylene carbonate and dissociated salts to generate an anion‐enrichment interface. This approach drives preferential anion decomposition at the inner Helmholtz plane, yielding a compact, columnar lithium deposit morphology and a Coulombic efficiency of nearly 99 %. Industrial‐scale anode‐free pouch cells achieving 442 Wh kg−1 with 80 % capacity retention after 100 cycles demonstrate the viability of this design under harsh conditions. Complementary work has shown that elevating the lithium electrode potential through enhanced ion pairing can weaken lithium’s reducing power and greatly suppress electrolyte decomposition. By mapping coordination‐structure shifts with vibrational spectroscopy and machine‐learning regression, tailored electrolytes exceed 99 % Coulombic efficiency and deliver stable cycling in lithium‐metal configurations. Foundational investigations into amide‐based electrolytes have also revealed that predicted interphase species form highly conductive and stable solid electrolyte interphases (SEIs), enabling high‐mass‐loading cathodes to retain capacity and suppress dendrite growth through denser lithium deposition and top‐down stripping mechanisms.

Research from all publishers

A comprehensive review of solvation‐structure regulation underscores the role of cation–anion–solvent interactions in stabilising electrode–electrolyte interphases. Strategies such as optimising salt concentration, introducing functional co-solvents and modulating solvent polarity are shown to control desolvation kinetics and SEI composition, with theoretical simulations offering mechanistic insight. In energy & environmental science, a sulfonamide‐based electrolyte has been designed to stabilise both lithium‐metal anodes and high‐voltage LiCoO₂ cathodes at cut-off voltages beyond 4.5 V. This formulation suppresses gas evolution, transition‐metal dissolution and impedance growth, achieving over 85 % capacity retention after 100 cycles. Earlier foundational work on concentrated electrolytes highlighted how increased salt loadings (>1 m) produce distinct SEI chemistries with enhanced stability and ion transport. These findings collectively illustrate that both bulk solvation and interfacial reaction engineering are essential to push performance boundaries in high‐energy lithium cells.

Electrolyte Engineering for High-Performance Lithium Battery Applications publication trend

The graph below shows the total number of articles in electrolyte engineering for high-performance lithium battery applications across all publications each year (not limited to Nature Index journals).

Technical terms

Solid electrolyte interphase (SEI): A passivation layer formed on electrode surfaces that governs ion transport, electronic insulation and long-term stability.

Solvation structure: The spatial arrangement of solvent molecules and anions around a lithium ion, influencing desolvation energy and interfacial reactions.

Coulombic efficiency (CE): The ratio of charge extracted to charge inserted during cycling; a measure of reversibility and electrolyte stability.

Superconcentrated electrolyte: A formulation in which salt concentration is so high that anion−solvent networks dominate, altering bulk and interfacial properties.

Anode‐free battery: A cell design without a pre-deposited lithium metal anode, relying on in situ plating and stripping from a lithium source in the cathode.

Ion pairing: Association of cations and anions in solution, which can raise electrode potentials and reduce parasitic side reactions.

References

1. Towards stable electrode–electrolyte interphases: Regulating solvation structures in electrolytes for rechargeable batteries. Interdisciplinary Materials (2023).
2. Superconcentrated electrolytes for a high-voltage lithium-ion battery. Nature Communications (2016).
3. Interface chemistry of an amide electrolyte for highly reversible lithium metal batteries. Nature Communications (2020).
4. Poly(Ethylene Oxide)-based Electrolyte for Solid-State-Lithium-Batteries with High Voltage Positive Electrodes: Evaluating the Role of Electrolyte Oxidation in Rapid Cell Failure. Scientific Reports (2020).
5. Anion-enrichment interface enables high-voltage anode-free lithium metal batteries. Nature Communications (2023).
6. Electrode potential influences the reversibility of lithium-metal anodes. Nature Energy (2022).
7. Stabilizing electrode–electrolyte interfaces to realize high-voltage Li||LiCoO 2 batteries by a sulfonamide-based electrolyte. Energy & Environmental Science (2021).