Rechargeable Lithium Metal Batteries

Abstract

Along with the state-of-the-art lithium-ion (Li-ion) batteries approaching their limitation in specific energy density, “beyond Li-ion” battery technologies have become alternative energy storage solutions due to their higher specific energy density. Among them, rechargeable lithium metal battery (LMB) has been considered as one of the most promising battery technologies that promises a great increase in energy density. Among the known anode materials, the Li metal has some unique and attractive features, such as an ultrahigh theoretical capacity (3,860 mAh g−1), a lowest negative electrochemical potential (−3.04 vs SHE), and a low gravimetric density (0.534 g cm−1). Therefore, Li metal has rendered as a potential ultimate anode material in rechargeable batteries. Furthermore, a combination of Li metal with oxygen (O2) or sulfur (S) cathodes brings more viable options for the next-generation high-energy rechargeable batteries (3,505 Wh kg−1 for Li-O2, 2,600 Wh kg−1 for Li-S batteries) with a great reduction in battery cost due to the high abundance and broad distribution of O2 and S sources. However, the use of Li metal anode in LMBs still causes some critical issues, including the well-known Li dendritic growth, uncontrolled interfacial reactions with electrolytes, and large volumetric change during Li plating/stripping process. The “short circuit” of the battery by dendrite formation and the continuous depletion of electrolytes/active bulk lithium have been significantly challenging the practical application of rechargeable LMBs. In this chapter, we will discuss the fundamental challenges for both Li anode and cathodes and the proposed strategies for rechargeable LMBs. A perspective on the future research direction is also presented to initiate more helpful thoughts and promote to solve the critical issues in this research field.