Nitrogen‐Rich Solvation Structures Enable Long‐Cycle Sodium Metal Batteries
Zhou‐Qing Xue, Chen‐Zi Zhao, Yao‐Peng Chen, Shi‐Jie Yang, Yi Yang, Shuai‐Qi Wang, Zi‐You Wang, Han‐Bing Zhu, Chong Yan, Jia‐Qi Huang
Abstract
Abstract Sodium (Na) metal anode exhibits excellent prospects in rechargeable battery systems owing to its high theoretical capacity (1166 mAh g −1 ) and its high abundance in the crust (2.3%). However, the electrochemical/mechanical unstable electrode interphases induce the rapid battery performance degradation and severely hinder the wide applications of Na metal batteries (SMBs). Herein, a nitrogen‐enriched coordinated solvation structure (NECS) is designed to simultaneously stabilize both electrodes through the innovation of solvation‐structure‐derived interphases engineering. The NECS‐derived N/O‐rich inorganic solid electrolyte interphase enables uniform and dendrite‐free Na plating/stripping for a working Na anode. NECS‐derived cathode electrolyte interphase, composed of NaN x O y , Na 3 N, and other Na containing compounds, significantly enhances the structural stability and electrochemical reversibility of the NaNi 1/3 Fe 1/3 Mn 1/3 O 2 (NFM) cathode. The Na||Na symmetric cell with NECS electrolyte remains stable for more than 4000 h. Besides, the Na||NFM full cell achieves 1000 cycles with 86.1% capacity retention using a high loading electrode of 7.5 mg cm −2 . The Na||NFM pouch cell configuration demonstrates a high energy density of 202.6 Wh kg −1 , underscoring the practicality of the proposed electrolyte strategy. The strategy solvation structure modulation proposed in this work offers a universal approach to overcoming the challenge between high‐energy‐density and long‐lifespan of SMBs.