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 Li22Sn5 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 Li22Sn5 framework in as-fabricated Li/Li22Sn5 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 Li22Sn5 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 LiCoO2 (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.