Nitrogen/Phosphorus Dual‐Doped Hard Carbon Anode with High Initial Coulombic Efficiency for Superior Sodium Storage. Issue 1 (15th November 2022)

• Record Type: Journal Article
• Authors: Wu, Sheng; Lu, Xiaoyi; Zhang, Kaili; Xu, Junling; Sun, Zhipeng
• Is Part Of: Batteries & supercaps. Volume 6:Issue 1(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-11-15
• Subjects: anode -- hard carbon -- nitrogen and phosphorus dual-doped -- sodium-ion battery -- synergistic effects; Electrochemistry -- Periodicals; Electrodes -- Periodicals; Electric batteries -- Periodicals; 621.31242
• DOI: 10.1002/batt.202200427
• Languages: English
• ISSNs: 2566-6223

Abstract

Abstract: Among anode materials for sodium‐ion batteries (SIBs), hard carbon (HC) gains more attention due to its low cost, high electronic conductivity, and renewable resources. However, sluggish kinetics result in its low‐rate capability and unfavorable cycle stability. Moreover, HC often presents low initial Coulombic efficiency (ICE), which also limits the utilization of the battery capacity and energy density. Herein, nitrogen and phosphorus dual‐doped HC (denoted as NPHC) with network structure is synthesized by a facile interfacial polymerization method, which endows the NPHC with synergistic effects of the enlarged interlayer spacing and improved conductivity. Consequently, the obtained NPHC exhibits a high reversible capacity (286 mAh g −1 at 0.1 A g −1 ), excellent rate capability (144 mAh g −1 at 10 A g −1 ), high ICE (71 %), and remarkable cyclability over 2000 cycles at 1 A g −1 . Moreover, the storage mechanism of sodium ions is examined by a series of ex‐situ characterizations. Additionally, when coupled with Na3 V2 (PO4 )2 F3 as a cathode, the full cell delivers superior cyclability (capacity retains 90 % over 300 cycles at 1 A g −1 ). This work may shed new insight into designing other carbon‐based electrode materials for high‐performance energy storage. Abstract : With hard carbon : we use a facile interfacial polymerization method to prepare hard carbon with N/P dual‐doped (NPHC), which shows superb rate capability (286 and 144 mAh g −1 at 0.1 and 10 A g −1, respectively). Through a series of analyses, NPHCS demonstrates a higher ion diffusion coefficient, capacitive contribution, and conductivity. This confirms that N/P dual‐doping is more beneficial to improve electrochemical performance.