A path towards high lithium-metal electrode coulombic efficiency based on electrolyte interaction motif descriptor

Abstract

The fundamental interactions and the as-derived microstructures among electrolyte components play a pivotal role in determining the bulk and interfacial properties of the electrolytes. However, the complex structure-property relationships remain elusive, leading to uncontrollable physicochemical characteristics of electrolytes and unsatisfied battery performance. Herein, we propose two interaction motif descriptors to quantify ion-solvent interactions spanning electrostatic to dispersion regimes. These descriptors are highly relevant to salt dissolution, phase miscibility, and electrode-electrolyte interface chemistries. Guided by the principle of minimizing ion-solvent and solvent-solvent interactions while ensuring sufficient salt dissociation, a representative electrolyte, i.e., lithium bis(fluorosulfonyl)imide dissolved in trimethyl methoxysilane and 1,3,5-trifluorobenzene with a molar ratio of 1:2.5:3.0, is designed, which achieves ~99.7% (±0.2%) Li plating/stripping Coulombic efficiency and endows 4.5 V Li||LiCoO2 with 90% capacity retention after 600 cycles at 0.2 C/0.5 C charge/discharge rate. Notably, Cu||LiNi0.5Co0.2Mn0.3O2 pouch cells with this electrolyte sustain over 100 stable cycles. By establishing quantitative relationships between interaction motifs and electrolyte functionalities, this work provides a universal framework for rational electrolyte design, paving the way for highly reversible lithium metal batteries. Electrolyte interactions critically govern battery performance yet lack precise design principles. The authors introduce interaction motif descriptors to design an electrolyte enabling 99.7% Li-metal Coulombic efficiency for 4.5 V batteries.

Key findings

• ▸High Coulombic efficiency (~99.7%) achieved with the designed electrolyte
• ▸Improved capacity retention (90%) after 600 cycles at 0.2 C/0.5 C charge/discharge rate
• ▸Over 1000 cycles sustained with Cu||LiNi0.5Co0.2Mn0.3O2 pouch cells using the new electrolyte

Keywords

Identifiers

DOI

10.1038/s41467-025-59955-0

PubMed

40394029

Journal

Nature Communications

Year

2025