In‐Plane Mesoporous 3D Flower‐Like Mo2Ti2C3Clx MXene Anodes for Li‐Ion Batteries: From Structure to Performance

Abstract

AbstractMXenes are known for their exceptional electrical conductivity and surface functionality, gaining interest as promising anode materials for Li‐ion batteries. However, conventional 2D multilayered MXenes often exhibit limited electrochemical applicability due to slow ion transport kinetics and low structural stability. Addressing these challenges, this study develops a 3D flower‐type double transition metal MXene, Mo2Ti2C3Clx, with precisely engineered in‐plane mesoporosity using HF‐free Lewis acid‐assisted molten salt method, coupled with intercalation and freeze‐drying. The molar ratio of Lewis acid to eutectic salts is meticulously controlled to create the mesoporosity, which is preserved through freeze‐drying. Molecular dynamics (MD) simulations assess the impact of in‐plane pore size on the structure and transport dynamics of electrolyte components. Density functional theory (DFT) shows that chlorine surface functional groups significantly reduce Li‐ion diffusion barriers, thereby enhancing ion transport and battery performance. Electrochemical evaluations reveal that small‐sized (2–5 nm) mesoporous Mo2Ti2C3Clx achieves a specific capacity of 324 mAh g−1 at 0.2 A g−1 and maintains 97% capacity after 500 cycles at 0.5 A g−1, outperforming larger‐pored (10 nm) and non‐porous variants. This research highlights a scalable strategy for designing mesoporous materials that optimize ion transport and structural stability, essential for advancing next‐generation high‐performance energy storage solutions.