Biomass-Derived Hard Carbon with Optimized Pseudo-graphitic Domains and Closed Pores for High-Performance Sodium Storage
Jia Song, Zhenzhu Wang, Jinshu Zhang, Chaozhong Liu, Meijuan Liu, Xinxing Ma, Xianjie Wang, Tai Yao, Z. L. Chen, Lizhi Li, Jiheng Zhang, Siping Tan, Bin Song
Abstract
Hard carbon (HC) stands out as a competitive anode for sodium-ion batteries, combining abundant, sustainable precursors with desirable electrochemical properties. By employing a simple solution-based approach to control cellulose decomposition, we engineer curved pseudographitic domains with expanded interlayer spacing and rich closed pores from peanut shell precursors. The resulting PSHC-7 delivers 401 mAh g –1 at 0.06 A g –1, an initial Coulombic efficiency of 88.6%, 289 mAh g –1 at 3.0 A g –1, and 93.1% capacity retention over 4500 cycles. In situ Raman and in situ XRD reveal a multistep “adsorption–intercalation–pore filling” mechanism, while theoretical calculations confirm that hierarchical pores and pseudocapacitive effects enhance Na + transport and storage. The full cells (NVP//PSHC-7) demonstrate practical applicability. This work provides an integrated experimental and theoretical framework linking precursor chemistry, microstructure, and electrochemical performance, offering a facile route to high-efficiency, durable, and cost-effective SIB anodes.