Bifunctional Electrospun Polymer-Inorganic Interlayer for Stable and High-Energy-Density Anode-Free Lithium Metal Batteries

초록

Lithium metal batteries have a high energy density but suffer from severe volume changes and non-uniform Li deposition, which hinder their long-term cycling stability. Herein, we present an innovative strategy employing an electrospun nitrile-butadiene rubber (NBR)/polyacrylonitrile (PAN) membrane embedded with Li–SiO2 nanoparticles as an interlayer for the Li anode. The elastic NBR matrix accommodates the volume deformation induced by Li plating and stripping, while the nitrile groups in PAN guide uniform Li+ ion flux through coordination interactions. Simultaneously, Li–SiO2 assists in regulating interfacial Li+ distribution and mechanically reinforces the fibrous network. This synergistic combination improves mechanical resilience, interfacial stability, and Li+ ion transport. As a result, pouch-type anode-free LMBs (AFLMBs) incorporating the interlayer and LiNi0.88Co0.10Al0.02O2 (active mass: 22.67 mg cm−2) cathode achieve a capacity retention of 76.9% after 250 cycles at 45°C and 1.0 C, outperforming cells without the interlayer. Moreover, the thickness increase of the pouch cell incorporating the LS-NP interlayer was limited to 16.6%, nearly half that observed for the cell without the interlayer. Our findings demonstrate that the cooperative functionality of the polymer matrix and Li–SiO2 nanoparticles establishes a robust and stable interface, highlighting the promise of the bifunctional interlayer for high-energy-density AFLMBs.

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