Fast-Charging and Long-Cycle Sodium-Ion Batteries Enabled by an Ultra-Stable Carbon Anode

The realization of rapid-charging sodium-ion batteries (SIBs) with exceptional power density represents a pivotal challenge for next-generation electric vehicles. Currently, carbonaceous anodes are considered the most technologically mature yet rate-limited candidate approaching commercialization. To address the bottlenecks of slow ion transport and interfacial instability in conventional carbon architectures, a hierarchical anode material has been designed by incorporating g-C₃N₄ electronic inert layer onto hollow carbon spheres (CN@HCS). This structure not only facilitates Na⁺ diffusion but also effectively suppresses side reactions, while enabling selective screening of electrons. As a result, the material exhibits outstanding rate capabilities, maintaining high performance even at a current density as high as 40 A g⁻¹, and demonstrates remarkable cycling stability over 40 000 cycles with negligible capacity decay. Consequently, the full battery enables rapid charging within 0.1 h and delivers a prolonged discharge duration of up to 1 h, accompanied by a high power density of 21 600 W kg⁻¹_{(cathode + anode)}. This work represents a significant advancement in the development of advance anode materials for SIBs.