Li Metal Anode Protection in Safe Rechargeable Batteries

Qiang Zhang

Tsinghua University

Abstract: Li metal is considered as the “Holy Grail” of energy storage systems. The bright prospects give rise to worldwide interests in the metallic Li for the next generation energy storage systems, including highly considered rechargeable metallic Li batteries such as Li-O2 and Li-sulfur (Li–S) batteries. However, the formation of Li dendrites induced by inhomogeneous distribution of current density on the Li metal anode and the concentration gradient of Li ions at the electrolyte/electrode interface is a crucial issue that hinders the practical demonstration of high-energy-density metallic Li batteries.

Free-standing graphene foam provides several promising features as underneath layer for Li anode, including (1) relative larger surface area than 2D substrates to lower the real specific surface current density and the possibility of dendrite growth, (2) interconnected framework to support and recycle dead Li, and (3) good flexibility to sustain the volume fluctuation during repeated incorporation/extraction of Li. The synergy between the LiNO3 and polysulfides provides the feasibility to the formation of robust SEI in an ether-based electrolyte. The efficient in-situ formed SEI-coated graphene structure allows stable Li metal anode with the cycling Coulombic efficiency of ∼97 % with high safety and efficiency performance. These results indicated that interfacial engineering of nanostructured electrode were a promising strategy to handle the intrinsic problems of Li metal anodes, thus shed a new light toward LMBs, such as Li-S and Li-O2 batteries with high energy density.

Biography: Prof. Qiang Zhang received his bachelor and Ph.D. degree from Tsinghua University in 2004 and 2009, respectively. After a stay in Case Western Reserve University, USA, and Fritz Haber Institute of the Max Planck Society, Germany, he joined in Tsinghua University at 2011. He held the Newton Advanced Fellowship from Royal Society, UK and the NSFC Young Scholar in China. His current research interests are advanced energy materials (lithium metal anode, lithium sulfur batteries, electrocatalysis). His citation is over 12000 times and his h-index is 58 now. More detaisl can be found at Google Scholar link: http://scholar.google.com/citations?user=qkcc0OYAAAAJ&hl=en and/or ResearchID link: http://www.researcherid.com/rid/B-1799-2012.