Ultrathin Li-rich Li-Cu alloy anode capped with lithiophilic LiC6 headspace enabling stable cyclic performance

Zihao Wang; Qijiu Deng; Zhicui Song; Yuchi Liu; Jianxiong Xing; Chaohui Wei; Yuehui Wang; Jingze Li

doi:10.1016/j.jcis.2023.03.191

Ultrathin Li-rich Li-Cu alloy anode capped with lithiophilic LiC₆ headspace enabling stable cyclic performance

J Colloid Interface Sci. 2023 Aug:643:205-213. doi: 10.1016/j.jcis.2023.03.191. Epub 2023 Apr 1.

Authors

Zihao Wang¹, Qijiu Deng², Zhicui Song¹, Yuchi Liu¹, Jianxiong Xing¹, Chaohui Wei³, Yuehui Wang⁴, Jingze Li⁵

Affiliations

¹ School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 611731, PR China; Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou 313001, PR China.
² International Research Center for Composite and Intelligent Manufacturing Technology, School of Materials and Engineering, Xi'an University of Technology, Xi'an 710048, PR China. Electronic address: dengqijiu@xaut.edu.cn.
³ Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou 313001, PR China.
⁴ Zhongshan Institute, University of Electronic Science and Technology of China, Zhongshan 528402, PR China.
⁵ School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 611731, PR China; Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou 313001, PR China. Electronic address: lijingze@uestc.edu.cn.

PMID: 37058895
DOI: 10.1016/j.jcis.2023.03.191

Abstract

Li-rich dual-phase Li-Cu alloy is a promising candidate toward practical application of Li metal anode due to its in situ formed unique three-dimensional (3D) skeleton of electrochemical inert LiCu_x solid-solution phase. Since a thin layer of metallic Li phase appears on the surface of as-prepared Li-Cu alloy, the LiCu_x framework cannot regulate Li deposition efficiently in the first Li plating process. Herein, a lithiophilic LiC₆ headspace is capped on the upper surface of the Li-Cu alloy, which can not only offer free space to accommodate Li deposition and maintain dimensional stability of the anode, but also provide abundant lithiophilic sites and guide Li deposition effectively. This unique bilayer architecture is fabricated via a facile thermal infiltration method, where the Li-Cu alloy layer with an ultrathin thickness around 40 μm occupies the bottom of a carbon paper (CP) sheet, and the upper part of this 3D porous framework is reserved as the headspace for Li storage. Notably, the molten Li can quickly convert these carbon fibers of the CP into lithiophilic LiC₆ fibers while the CP is touched with the liquid Li. The synergetic effect between the LiC₆ fibers framework and LiCu_x nanowires scaffold can ensure a uniform local electric field and stable Li metal deposition during cycling. As a consequence, the CP capped ultrathin Li-Cu alloy anode demonstrates excellent cycling stability and rate capability.

Keywords: Headspace; Li metal anode; Li-Cu alloy; LiC(6); LiCu(x).