Chen Jing, Deng Xuetian, Jia Xin, Gao Yang, Chen Han, Lin Zhiqun, Ding Shujiang
School of Chemistry, Engineering Research Center of Energy Storage Materials and Devices, Ministry of Education, State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, P. R. China.
Department of Chemical and Biomolecular Engineering, National University of Singapore, 21 Lower Kent Ridge Road, Singapore 119077, Singapore.
J Am Chem Soc. 2024 Nov 13;146(45):30836-30847. doi: 10.1021/jacs.4c08766. Epub 2024 Oct 30.
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 LiN and LiS. 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 and 1 mA h cm conditions. Furthermore, full cell pairing DSE/Li anode with LiFePO (LFP) or high-voltage LiNiMnCoO (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). This study underscores the effectiveness of the ion-dipole interaction-enabled DSE network in developing stable, high-energy-density LMBs.
不稳定的锂（Li）/电解质界面导致循环效率低下和枝晶生长不受抑制，严重阻碍了锂金属电池（LMB）的实际应用，尤其是在碳酸盐电解质中。在此，我们提出了一种利用动态超分子弹性体（DSE）界面层的强大方法，该界面层能够与锂金属发生还原反应，自发形成强大的锂离子-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配位的Li-O相互作用实现快速Li传输，而富含亲锂性电负性位点的硬相则驱动包括LiN和LiS在内的快离子传导固体电解质界面成分的生成。此外，由软相和硬相组成的动态弹性DSE网络可保护锂阳极免受电解质腐蚀，并在循环过程中适应体积变化。DSE层的所有特性协同促进均匀的Li沉积并抑制Li枝晶的生长，确保锂阳极稳定且无枝晶。因此，包含DSE层的对称Li||Li电池在1 mA cm和1 mA h cm条件下实现了超过6000 h的循环稳定性。此外，即使在有限Li（40 μm）和超高负载NMC811阴极（21.5 mg cm）的受限条件下，将DSE/Li阳极与LiFePO（LFP）或高压LiNiMnCoO（NMC811）阴极配对的全电池也表现出高效的Li沉积和循环稳定性。这项研究强调了离子-偶极相互作用驱动的DSE网络在开发稳定、高能量密度LMB方面的有效性。
