西安交通大学丁书江团队报道了Li⁺-偶极子相互作用实现无枝晶锂金属阳极的动态超分子弹性体界面层。相关研究成果于2024年10月30日发表于国际顶尖学术期刊《美国化学会杂志》。

锂（Li）/电解质界面不稳定，导致循环效率低和枝晶生长不受限制，严重阻碍了锂金属电池（LMBs）的实际应用，特别是在碳酸盐电解质中。

该文中，研究人员提出了一种利用动态超分子弹性体（DSE）界面层的稳健方法，该界面层能够被Li金属还原，自发形成强烈的Li⁺偶极相互作用，从而增强碳酸盐电解质中的界面稳定性。DSE结构中的软相通过松散协调的Li⁺-O相互作用实现了Li⁺的快速传输，而富含电负性亲锂位点的硬相则驱动了，包括Li₃N和Li₂S在内的快离子传导固体电解质界面组分的产生。

由软相和硬相组成的动态弹性DSE网络保护锂阳极免受电解质腐蚀，并适应循环过程中的体积变化。DSE层的所有特征协同促进了Li⁺的均匀沉积，抑制了Li枝晶的传播，确保了稳定和无枝晶的Li阳极。因此，包含DSE层的对称Li||Li电池在1mA cm^-2和1mA h cm^-2条件下，实现了超过6000小时的循环稳定性。

此外，全电池配对DSE/Li阳极与LiFePO₄（LFP）或高压LiNi_0.8Mn_0.1Co_0.1O₂（NMC811）阴极，具有高效的Li沉积和循环稳定性，即使在有限Li（40μm）和超高负载NMC811阴极（21.5 mg cm^-2）的约束条件下也是如此。

该项研究强调了离子-偶极相互作用驱动的DSE网络，在开发稳定、高能量密度LMBs方面的有效性。

附：英文原文

Title: Li+ Ion-Dipole Interaction-Enabled a Dynamic Supramolecular Elastomer Interface Layer for Dendrite-Free Lithium Metal Anodes

Author: Jing Chen, Xuetian Deng, Xin Jia, Yang Gao, Han Chen, Zhiqun Lin, Shujiang Ding

Issue&Volume: October 30, 2024

Abstract: The unstable lithium (Li)/electrolyte interface, causing inferior cycling efficiency and unrestrained dendrite growth, has severely hampered the practical deployment of Li metal batteries (LMBs), particularly in carbonate electrolytes. Herein, we present a robust approach capitalizing on a dynamic supramolecular elastomer (DSE) interface layer, which is capable of being reduced with Li metal to spontaneously form strong Li+ ion-dipole interaction, thereby enhancing interfacial stability in carbonate electrolytes. The soft phase in the DSE structure enables fast Li+ transport via loosely coordinated Li+–O interaction, while the hard phase, rich in electronegative lithiophilic sites, drives the generation of fast-ion-conducting solid electrolyte interface components, including Li3N and Li2S. Furthermore, the dynamically resilient DSE network composed of soft and hard phases protects Li anodes from electrolyte corrosion and accommodates volume changes during cycling. All features of the DSE layer synergistically facilitate uniform Li+ deposition and suppress Li dendrite propagation, ensuring a stable and dendrite-free Li anode. Consequently, the symmetric Li||Li cell incorporating the DSE layer achieves cycling stability exceeding 6000 h under 1 mA cm–2 and 1 mA h cm–2 conditions. Furthermore, full cell pairing DSE/Li anode with LiFePO4 (LFP) or high-voltage LiNi0.8Mn0.1Co0.1O2 (NMC811) cathodes exhibits high-efficiency Li deposition and cycling stability, even under constrained conditions of limited Li (40 μm) and ultrahigh loading NMC811 cathode (21.5 mg cm–2). This study underscores the effectiveness of the ion-dipole interaction-enabled DSE network in developing stable, high-energy-density LMBs.

DOI: 10.1021/jacs.4c08766

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c08766