Homogenizing the Li-ion flux by multi-element alloying modified for 3D dendrite-free lithium anode

Abstract

Metallic Li anode has attracted much attention for the high energy density rechargeable Li batteries, owing to the low potential and ultrahigh theoretical specific capacity. However, the Li dendrite growth and high activity of Li hinder the application of lithium anode. In this work, the multiplex alloy composite skeletons have been prepared via a facile two-step preparation method to solve the drawbacks of Li anode, which can form uniformly distributed nucleation sites, homogenize Li-ion flux and reduce local ionization density to suppress the growth of lithium dendrites. Based on the analysis of cross-sectional operando microscopy images, it can be confirmed that the synthesized 3D composite alloy anodes can effectively suppress the formation and growth of lithium dendrites. Li-Mg-Ca electrode exhibits the most excellent mechanical property, thermostability, interfacial stability and electrochemical cycling stability. Specifically, Li-Mg-Ca alloy electrode exhibits the stable charge-discharge cycling performance for 1000 h (pristine Li only for 120 h) at a current density of 2 mA cm−2 for 4 mAh cm−2. The practical 350 Wh kg−1 pouch cell works well and meets the energy requirements of electronic devices. Importantly, the research work in this article provides research ideas for the later lithium-free anode materials.