Multiscale Engineered Bionic Solid-State Electrolytes Breaking the Stiffness-Damping Trade-Off.

All-solid-state lithium metal batteries are regarded as next-generation devices for energy storage due to their safety and high energy density. The issues of lithium dendrites and poor mechanical compatibility with electrodes present the need for developing solid-state electrolytes with high stiffness and damping, but it is a contradictory relationship. Here, inspired by the superstructure of tooth enamel, we develop a composite solid-state electrolyte composed of amorphous ceramic nanotube arrays intertwined with solid polymer electrolytes. This bionic electrolyte exhibits both high stiffness (Young's modulus=15GPa, hardness = 0.13GPa) and damping (tanδ= 0.08), breaking the trade-off. Thus, this composite electrolyte can not only inhibit Li dendrites growth but also ensure intimate contact with electrodes. Meanwhile, it also exhibits considerable Li+ transference number (0.62) and room temperature ionic conductivity (1.34×10-4 S cm-1), which is attributed to oxygen vacancies of the amorphous ceramic effectively decoupling the Li-TFSI ion pair. Consequently, the assembled Li symmetrical battery shows an ultra-stable cycling (>2000 hours at 0.1 mA cm-2 at 60 °C, >500hours at 0.1mA cm-2 at 30 °C). Moreover, the LiFePO4/Li and LiNi0.8Co0.1Mn0.1O2/Li all-solid-state full cells both show excellent cycling performance. We demonstrate that this bionic strategy is a promising approach for the development of high-performance solid-state electrolytes.