Work

Solvent molecule layer assisted rapid lithium ion transport in MOF pore for wide-temperature solid-state lithium battery

Year: 2025
Type: article
Abstract: Two-dimensional metal-organic frameworks (2D MOFs), coupling the individual advantages of organic polymer with excellent flexibility and processability, as well as inorganic crystal with well-ordered and temperature-independent structure, are emerging solid-state electrolyte (SSE) materials for wide-temperature solid-state lithium batteries. However, present MOFs have seldom been directly utilized as SSEs, due to the insurmountable transport energy barrier and resultant low ionic conductivity. Here, we report a lamellar MOF electrolyte with high ionic conductivity over wide-temperature ranges through confining DMF (N, N-dimethylformamide, DMF) solvent into the ordered pore channel of 2D MOF lamellar framework. We demonstrate that, the fine-tuned microstructure of pore walls could induce the rearrangement of DMF solvent layer, forming long-range ordered and stable solvent layer along pore walls. The solvent layer then acts as low-energy-barrier lithium ion transport path, affording MOF SSE high ionic conductivity over wide-temperature ranges (2.87 × 10−4 – 1.58 × 10−3 S cm−1 at −20 – 100 oC), surpassing most of the currently reported solid-state electrolytes. The MOF SSE also exhibits high tLi+ of 0.81 and low activation energy of 0.106 eV. Consequently, the assembled LiFePO4|Li half-cell can stably cycle over wide-temperature ranges, retaining high discharge specific capacities of 158.4 mAh g−1 at −20 oC and 171.2 mAh g−1 at 60 oC, respectively, after 300 cycles. This work offers an innovative approach for the design of advanced ion conductors towards wide-temperature solid-state lithium batteries.
Language: English
Open Access status: gold
Estimated APC paid: $5,290
OpenAlex ID: W4415728195
FWCI: 0.68
Cites: 47
Cited by: 3
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