High-pressure-assisted discovery of porous carbon frameworks from NaC6 for high-performance sodium-ion battery anodes

Designing high-performance anode materials with rapid Na-ion transport, high capacity, and structural stability remains a critical challenge for sodium-ion batteries (SIBs). In this work, we propose a high-pressure-assisted structure design strategy that utilizes sodium as a chemical template to guide the formation of the carbon framework. Using global structure prediction at 30 GPa, two low-energy NaC 6 phases—Na-bct-C 12 and Na-IGN—were identified and subsequently transformed into porous carbon frameworks after sodium removal. The resulting bct-C 12 and interlocked graphene network (IGN) structures exhibit excellent dynamical and thermal stability, metallic or topological semimetal electronic features. They demonstrate outstanding sodium storage performance: theoretical capacities 372 mAh/g, ultra-fast Na + diffusion with coefficients reaching up to 3.75 × 10 -4 cm 2 /s, and minimal volume expansion (<7%) during sodiation. This study demonstrates that pressure-assisted templating enables the discovery of metastable but functionally superior porous carbon phases, providing a robust framework for the rational design of high-rate SIB anodes.