Li metal is considered to be an ultimate anode for metal batteries owing to its extremely high theoretical capacity and lowest potential. However, numerous issues such as short lifespan and infinite volume expansion caused by the dendrite growth during Li plating/stripping hinder its practical usage. These challenges become more grievous under high current densities. Herein, 3D porous MXene aerogels are proposed as scaffolds for high-rate Li metal anodes using Ti C as an example. With high metallic electron conductivity, fast Li ion transport capability, and abundant Li nucleation sites, such scaffolds could deliver high cycling stability and low overpotential at current density up to 10 mA cm . High rate performance is also demonstrated in full cells with LiFePO as cathodes. This work provides a new type of scaffolds for Li metal anodes and paves the way for the application of non-graphene 2D materials toward high energy density Li metal batteries.

Li metal is an ideal anode for next‐generation batteries because of its high theoretical capacity and low potential. However, the unevenly distributed stress in Li metal anodes (LMAs) induced by volume fluctuation may cause the electrode to fracture easily, especially during high‐rate plating/stripping processes. Here fracture‐resistant LMAs using the concept of bulk nanostructured materials are designed via a metallurgical process. In bulk nanostructured Li (BNL), ionic conducting phases exist at grain boundaries, which promote Li+ transport. The refined Li grain size and precipitation hardening in BNL enhances the mechanical strength and fatigue endurance, alleviating the unevenly distributed stress and preventing electrode pulverization. Density functional theory is used to investigate the binding energy between Li and various kinds of oxides and SiO2 is found to be optimal additive among screened oxides. BNL has 91% of the theoretical capacity of Li metal. In full cells with BNL anode, LiFePO4 could deliver capacity of 90 mAh g−1 at 10C, an order of magnitude higher than that in full cells with Li foil anode. This strategy is expected to pave the way for fracture‐resistant LMAs in high‐rate cycling with maximum capacity.