Centrifugally Spun Binder-Free N, S-Doped Ge@PCNF Anodes for Li-Ion and Na-Ion Batteries

Yanılmaz M., Cihanbeyoğlu G., Kim J.

ACS Omega, vol.8, no.19, pp.16987-16995, 1 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 8 Issue: 19
  • Publication Date: 1
  • Doi Number: 10.1021/acsomega.3c00990
  • Journal Name: ACS Omega
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Directory of Open Access Journals
  • Page Numbers: pp.16987-16995
  • Istanbul Technical University Affiliated: Yes


Germanium has a high theoretical capacity as an anode material for sodium-ion batteries. However, germanium suffers from large capacity losses during cycling because of the large volume change and loss of electronic conductivity. A facile way to prepare germanium anodes is critically needed for next-generation electrode materials. Herein, centrifugally spun binder-free N, S-doped germanium@ porous carbon nanofiber (N, S-doped Ge@ PCNFs) anodes first were synthesized using a fast, safe, and scalable centrifugal spinning followed by heat treatment and N, S doping. The morphology and structure of the resultant N, S-doped Ge@ PCNFs were investigated by scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray mapping, Raman spectroscopy, and X-ray diffraction, while electrochemical performance of N, S-doped Ge@ PCNFs was studied using galvanostatic charge-discharge tests. The results demonstrate that a nanostructured Ge homogeneously distributed on tubular structured porous carbon nanofibers. Moreover, N, S doping via thiourea treatment is beneficial for lithium- and sodium-ion kinetics. While interconnected PCNFs buffered volume change and provided fast diffusion channels for Li ions and Na ions, N, S-doped PCNFs further improved electronic conductivity and thus led to higher reversible capacity with better cycling performance. When investigated as an anode for lithium-ion and sodium-ion batteries, high reversible capacities of 636 and 443 mAhg-1, respectively, were obtained in 200 cycles with good cycling stability. Centrifugally spun binder-free N, S-doped Ge@ PCNFs delivered a capacity of 300 mAhg-1 at a high current density of 1 A g-1, indicating their great potential as an anode material for high-performance sodium-ion batteries.