Utilizing SnO2 Encapsulated within a Freestanding Structure of N-Doped Carbon Nanofibers as the Anode for High-Performance Lithium-Ion Batteries

Abstract

Rechargeable Li-SnO2 batteries suffer from issues such as poor electronic/ionic conductivity and huge volume changes. In order to overcome these inherent limitations, this study designed a cell with a unique hierarchical structure, denoted as SnO2@PCNF. The SnO @PCNF cell design incorporates in-situ generated SnO2 nanoparticles strategically positioned within N-doped porous carbon nanofibers (PCNF). The in-situ generated SnO2 nanoparticles can alleviate strains during cycling and shorten the pathway for the ions and electrons, improving the utilization of active materials. Moreover, the N-doped PCNF establishes a continuously conductive network to further increase the electrical conductivity and also buffers the significant volume changes that occur during charging and discharging. The resulting SnO2@PCNF cell exhibits outstanding electrochemical performance and stable cycling characteristics. Notably, a reversible capacity of 520 mAh g-1 was achieved after 100 cycles at 70 mA g-1. Even under a higher current density of 1 A g -1, the cell maintained a capacity retention of 393 mAh g-1 after 1,000 cycles. These results highlight the SnO2@PCNF cell’s exceptional cycling stability and superior rate capability.