General Scalable Synthesis of Mesoporous Metal Oxide Nanosheets with High Crystallinity for Ultralong‐Life Li–S Batteries

Abstract Mesoporous metal oxide nanosheets (MMONs) are demonstrated great promise for various catalytic applications such as water splitting, CO₂ reduction, and metal–sulfur batteries. However, limited by the conventional high‐temperature synthetic routes, the prepared MMONs expose only a small portion of the effective catalytic sites, which greatly restricts their electrocatalytic activity. Herein, a facile and general glycine‐assisted strategy is developed to synthesize a series of MMONs with high crystallinity and remarkable porosity. Impressively, single‐phase perovskite type MMONs containing up to ten metal cations can be synthesized easily using this method without any further purification step. As a proof of concept, the Li–S cell with mesoporous LaFe_0.4Co_0.2Ni_0.2Cu_0.2O₃ nanosheets as catalyst achieves superior ultralong cycling life over 1500 cycles at 2 C with only 0.041% capacity decay per cycle and a high areal capacity reaching 6.0 mAh cm⁻² at a low electrolyte/sulfur ratio of 5.9 µL mg⁻¹. The improved performance is attributed to abundant active sites and synergistic contribution of multicomponent. This work paves a new avenue for the general synthesis of advanced MMONs and will inspire the practical applications in different fields.