Synchronic Multilevel Assembly Toward Mesoporous Nanosized Intercalation-Type Framework Anodes for Fast-Charging...

Intercalation-type metal oxides are promising anodes for fast-charging sodium-ion batteries (SIBs). However, viable electrode candidates remain scarce, constituting a major bottleneck and motivating intensive research into diverse structural frameworks. Here, we report a synchronic multilevel assembly strategy for synthesizing mesoporous intercalation-type metal oxide framework anodes. Atomic-scale assembly of cations, combined with in situ formation of conductive carbon networks, enables the synthesis of structurally tunable nanosized sodium titanate and overcomes the challenges of preparing multimetal oxide nanocrystals under high temperatures. The M-Na₄Ti₅O₁₂/C composite delivers superior rate capability (∼115 mAh g^-1 at 10 A g^-1) and cycling stability (<0.023% capacity fade per cycle over 1000 cycles at 0.2 A g^-1) for sodium storage. Its outstanding kinetics arise from ultrafast Na⁺ diffusion through interconnected mesoporous channels and low-barrier, nanoscale ion-conduction pathways. A pouch cell delivers a power density of ∼4.7 kW kg^-1 and cycles stably for 1200 cycles, outperforming hard carbon at high rates. This work establishes a rational design framework for developing high-rate battery materials.