Multifunctional Silanization Interface for High‐Energy and Low‐Gassing Lithium Metal Pouch Cells

Lithium (Li) metal has attracted unprecedented attention as the ultimate anode material for future rechargeable batteries, but the electrochemical behavior (such as Li dendrites and gassing problems) in real Li metal pouch cells has received little attention. To achieve realistic high‐energy Li metal batteries, the designed solid electrolyte interface to suppress both Li dendrites and catastrophic gassing problems is urgently needed at cell level. Here, an efficient multifunctional silanization interface (MSI) is proposed for high‐energy Li metal pouch cells. Such an MSI not only guides uniform nucleation and growth of Li metal but also suppresses interfacial parasitic reactions between Li metal and electrolyte. As a result, under harsh conditions (negative to positive electrode capacity ratio of 2.96 and electrolyte weight to cathode capacity ratio of 2.7 g Ah−1), a long‐running lifespan (over 160 cycles with a capacity retention of 96% at 1 C), and low‐gassing behavior of realistic high‐energy Li metal pouch cell (1 Ah, 300 Wh kg−1) is achieved. This work opens a promising avenue toward the commercial applications of high‐energy Li metal batteries. A multifunctional silanization interface (MSI) is proposed for a realistic high‐energy Li metal pouch cell (1 Ah, 300 Wh kg−1). Such an MSI enables high‐energy Li metal pouch cells to cycle more than 160 cycles with a capacity retention of 96% at 1 C. More importantly, the gassing behavior of the pouch cell is significantly suppressed with the assistance of the MSI.