Complementary combination of lithium protection strategies for robust and longevous lithium metal batteries

A ten-fold higher specific capacity than commercial graphite anodes makes lithium metal anodes extremely attractive for rechargeable battery applications. However, the safety concerns associated with lithium dendrites represent a major barrier to the practical application of lithium metal batteries. Over the past decades, several mechanisms for the growth of lithium dendrites have been proposed from different perspectives. This has led to a variety of strategies to protect the lithium metal anode, such as preparation of artificial solid electrolyte interphase (SEI) and pseudo-liquid anodes. In this review, we present an overview of protection strategies for lithium metal anodes in terms of preventing lithium dendrite growth and regulating lithium deposition behaviours or healing the existing lithium dendrites. Firstly, the mechanisms of dendrite growth and anode corrosion are summarized and compared to better understand the lithium-ion deposition behaviours, which is critical for theoretically guiding the exploration of highly stable lithium anodes. Subsequently, the potential for integrating different strategies is discussed to combine and make full use of the advantages of each strategy, which can facilitate the development of emerging strategies and the improvement of established ones. The availability of the proposed strategies will further narrow the gap between experimental research and the commercial application of rechargeable lithium metal batteries.