Synergistic Regulation of Li-Ion Transport and Crystallographic Orientation via Lanthanum Iodide for High-Performance Lithium Metal Anodes
Yuanyuan Wang, Ziqing Yao, Man Pang, Zhongwei Jiang, Tao Pan, Chunman Zheng, Shuangke Liu, Yujie Li, Weiwei Sun
Abstract
Research on lithium metal anodes confronts critical challenges from uncontrolled dendrite growth and unstable SEIs, especially under high-energy conditions. Here, we report a surface engineering strategy utilizing lanthanum triiodide (LaI 3 ) to regulate Li-ion transport dynamics and lithium crystal growth kinetics. LaI 3 reacts with Li to form metallic La and LiI, creating a surface modification layer in inorganic components, which enhances interfacial stability and enables stable cycling of the Li anode. Further experiments and calculations show that the La/LiI-rich inorganic SEI layer regulates Li deposition orientation and improves interfacial transport kinetics. Specifically, La doping elevates the s -band center of the Li (200) facet, minimizing the s -band center energy difference and promoting the preferred orientation and planar growth of Li deposition. Meanwhile, LiI-rich SEI exhibits an ultralow Li + migration barrier (0.035 eV) and superior Li + adsorption, enabling rapid ion transport and uniform deposition. The synergistic effects are manifested in practical 5.93 Ah Li||NCM90 pouch cells, achieving a high energy density of 500.93 Wh kg –1 and maintaining 86.8% capacity retention after 50 cycles with an average Coulombic efficiency of 99.47%. This work presents a scalable approach for high-energy lithium metal batteries by combining simultaneous crystallographic orientation control and SEI engineering through interfacial chemistry manipulation.