In-situ construction of lithium-tin alloy skeleton as a lithiophilic host for lithium metal anode

Abstract

Lithium (Li) metal holds great promise to be the ideal anode for next-generation high-energy-density Li metal battery . However, the catastrophic dendritic Li propagation and the infinite relative volume change during cycling impede the implementation of Li metal anode . Herein, lithiophilic Li 22 Sn 5 with high ionic and electronic conductivity was in-situ implanted into metallic Li matrix via a scalable mechanical kneading operations and the subsequent heat treatment protocol. Homogeneous Li 22 Sn 5 framework in as-fabricated Li/Li 22 Sn 5 composite electrode effectively promoted the even distribution of Li + flux and ions transport kinetics, thus suppressing the formation and growth of dendritic Li. Additionally, robust Li 22 Sn 5 alloy served as the ideal skeleton steadily endured the stress from the expansion and contraction of the electrode upon cycling, enabling an electrode structural integrity. As a result, the assembled full cell with coin-cell con Declaration of Interest Statementuration using high loading LiCoO 2 (16.6 mg cm −2 ) delivered an impressive capacity retention of 91.9 % for 100 cycles at 0.5 C with a low Negative/Positive (N/P) ratio of 3:1. The in-situ construction of lithiophilic alloy skeleton as a stable host provides an alternative approach for achieving long-lifespan Li metal battery . A thickness-controllable Li/Li 22 Sn 5 composite with in-situ formed lithiophilic Li 22 Sn 5 skeleton as the ideal host was fabricated via scalable mechanical kneading operations and the subsequent heat treatment protocols. The as-fabricated Li/Li 22 Sn 5 composite electrodes demonstrated superior electrochemical performance in full cells at a low Negative/Positive ratio.