Three-dimensional lithiophilic Li22Sn5 alloy skeleton for dendrite-free and ultrahigh-capacity Li metal anode. (10th February 2022)

• Record Type: Journal Article
• Authors: Liu, Yuchi; Chen, Tao; Xue, Jing; Wang, Zihao; Xing, Jianxiong; Zhou, Aijun; Li, Jingze
• Is Part Of: Electrochimica acta. Volume 405(2022)
• Publication Date: 2022-02-10
• Subjects: Li-rich alloy -- Composite anode -- SnLi90 -- Li battery -- 3D skeleton; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2021.139787
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Uneven deposition and serious volume change restrict the commercial application of Li metal anode. Sn based alloy is pursued as the advanced anode via an alloying/dealloying mechanism while considering its resource abundance, low price, and high specific capacity. Herein, a three-dimensional (3D) Li22 Sn5 alloy skeleton is integrated with Li metal phase via phase-segregation process by a facial melting method, in which Li-rich dual-phase Li-Sn alloy named SnLi90 is produced. The free Li phase accounts for a huge proportion of the electrode weight and acts as the active material offering ultra-high specific capacity of 3087 mAh g −1 . Alternatively, the unique interconnected rod-like Li22 Sn5 network serves as electrochemical "inert" framework due to its much higher redox potential. The favorable Li affinity of the Li22 Sn5 skeleton contributes to conformal Li deposition. Consequently, the SnLi90 anode can cycle stably for 1500 h in ester electrolyte at 1 mA cm −2 and 1 mAh cm −2, almost three times longer than that of the bare Li anode. Graphical abstract: The SnLi90 anode contains two phases, i.e., Li metal and Li22 Sn5 alloy. Li enables high specific capacity. Li22 Sn5 skeleton maintains structural integrity, electrochemical "inertness" and induces conformal deposition of Li. Image, graphical abstract