Simple Synthesis and Sodium Storage Analysis of Ultra‐High Nitrogen‐Doped Core‐Shell Mesoporous Carbon Nanospheres

Abstract The development of easily synthesized high‐performance anode materials is crucial for the current energy storage (ES) field. Considering the potential of nitrogen‐doped core‐shell mesoporous carbon materials, a simple micelle‐induced high‐temperature pyrolysis method is employed to synthesize ultra‐high nitrogen‐doped (21.1 wt.%) core‐shell mesoporous carbon nanospheres (CYMCS). This material exhibits excellent volume expansion resistance, achieves a high reversible sodium storage capacity of up to 283 mAh g⁻¹ at a current density of 0.1 A g⁻¹, and maintains stable cycling performance for over 10000 cycles at a high current density of 5 A g⁻¹. Moreover, previous research has provided limited insights into the specific mechanisms behind the low initial coulombic efficiency (ICE) observed in CYMCS and other related porous materials. To address this, the study not only delves into the electrochemical performance of CYMCS but also provides a comprehensive analysis of the formation mechanisms of the solid electrolyte interphase (SEI) and the electrolyte decomposition process, revealing the connections between these processes and their impact on ICE. Overall, this research not only offers new insights into the synthesis and performance optimization of CYMCS materials for sodium storage applications but also provides valuable guidance for the design of related carbon materials and strategies to improve ICE.