Suppressing the Dendrite Growth on Li Metal Anode Via Manipulating the Solid Electrolyte Interface (SEI) Formation

Abstract

The progressive advancements in communication and transportation has changed human daily life to a great extent. While important advancements in battery technology has come since its first demonstration, the high energy demands needed to electrify the automotive industry have not yet been met with the current technology. One possible anode is the Li metal, which has several distinct advantages over other anode materials. For example, it possesses extremely high theoretical specific capacity of 3860 mA h g- 1, and the lowest negative electrochemical potential.1 However, the uncontrollable Li dendrite growth on the Li metal during electrochemical cycling will cause serious safety problem, which brings up challenges in broadening the application of Li metal for Li batteries. In this work, we successfully suppressed the Li dendrite growth on the Li anode by designing novel electrolyte systems. We observed an uniform solid electrolyte interface (SEI) layer was coated on the surface of Li metal anode through the scanning electron microscopy, this SEI layer helps to prevent the Li dendrite formation. Fig.1 compares the morphologies of deposited Li using different electrolytes. We also manipulated the composition of SEI by using different combinations of electrolyte solvents and Li salts. The chemical composition and structural information of the SEIs are investigated by X-ray Photoelectron Spectroscopy, X-ray diffraction, and Infrared Spectroscopy. Furthermore, this work demonstrates a new strategy of manipulating beneficial SEI formation, which shed light on the application of Li metal anode in high energy density batteries. Reference 1. W. Xu, J. L. Wang, F. Ding, X. L. Chen, E. Nasybutin, Y. H. Zhang and J. G. Zhang, Energy & Environmental Science, 2014, 7, 513-537. Figure 1