Sodium‐metal batteries (SMBs) are considered as a compliment to lithium‐metal batteries for next‐generation high‐energy batteries because of their low cost and the abundance of sodium (Na). Herein, a 3D nanostructured porous carbon particle containing carbon‐shell‐coated Fe nanoparticles (PC‐CFe) is employed as a highly reversible Na‐metal host. PC‐CFe has a unique 3D hierarchy based on sub‐micrometer‐sized carbon particles, ordered open channels, and evenly distributed carbon‐coated Fe nanoparticles (CFe) on the surface. PC‐CFe achieves high reversibility of Na plating/stripping processes over 500 cycles with a Coulombic efficiency of 99.6% at 10 mA cm–2with 10 mAh cm–2in Na//Cu asymmetric cells, as well as over 14 400 cycles at 60 mA cm–2in Na//Na symmetric cells. Density functional theory calculations reveal that the superior cycling performance of PC‐CFe stems from the stronger adsorption of Na on the surface of the CFe, providing initial nucleation sites more favorable to Na deposition. Moreover, the full cell with a PC‐CFe host without Na metal and a high‐loading Na3V2(PO4)3cathode (10 mg cm–2) maintains a high capacity of 103 mAh g–1at 1 mA cm–2even after 100 cycles, demonstrating the operation of anode‐free SMBs.
Traditional challenges of poor cycling stability and low Coulombic efficiency in Zinc (Zn) metal anodes have limited their practical application. To overcome these issues, this work introduces a single metal‐atom design featuring atomically dispersed single copper (Cu) atoms on 3D nitrogen (N) and oxygen (O) co‐doped porous carbon (CuNOC) as a highly reversible Zn host. The CuNOC structure provides highly active sites for initial Zn nucleation and further promotes uniform Zn deposition. The 3D porous architecture further mitigates the volume changes during the cycle with homogeneous Zn2+flux. Consequently, CuNOC demonstrates exceptional reversibility in Zn plating/stripping processes over 1000 cycles at 2 and 5 mA cm−2with a fixed capacity of 1 mAh cm−2, while achieving stable operation and low voltage hysteresis over 700 h at 5 mA cm−2and 5 mAh cm−2. Furthermore, density functional theory calculations show that co‐doping N and O on porous carbon with atomically dispersed single Cu atoms creates an efficient zincophilic site for stable Zn nucleation. A full cell with the CuNOC host anode and high loading V2O5cathode exhibits outstanding rate‐capability up to 5 A g−1and a stable cycle life over 400 cycles at 0.5 A g−1.
more » « less- PAR ID:
- 10484078
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Energy Materials
- ISSN:
- 1614-6832
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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