Fabrication of Si Nanoparticles Encapsulated into Porous N-Doped Carbon for Superior Lithium Storage Performances

• Published in: Journal of nanoscience and nanotechnology Vol. 20; no. 2; p. 949
• Main Authors: Tang, Ze-Hua, Xie, Jin-Feng, Bian, Zheng-Xu, Zhang, Jun-Hao, Liu, Yuan-Jun, Guo, Xing-Mei, Kong, Qing-Hong, Yuan, Ai-Hua
• Format: Journal Article
• Language: English
• Published: United States 01.02.2020
• ISSN: 1533-4899
• DOI: 10.1166/jnn.2020.16927

To improve lithium storage performances of Si anode for lithium-ion batteries, Si nanoparticles encapsulated into porous N-doped carbon (Si@PNC) was devised and prepared by metal nitrate accelerated polymer blowing process. The Si@PNC composites have large specific surface area of 221.7 m² g and possess a great deal of mesopores and micropores, which are attributed to the carbonization of PVP and etching metallic nanoparticles. As anode for lithium ion battery, the initial discharge capacity of Si@PNC composites is high to 1626 mA h g , and the specific capacity still retains 1030 mA h g after 200 cycles at 200 mA g . Meanwhile, remarkably improved rate capability is achieved with an excellent reversible specific capacity of 375 mA h g at 5.0 A g . The excellent lithium storage performances benefit from the unique porous core-shell structure of Si@PNC composites, which improve electroconductivity, reduce volume dilatation and accelerate lithium ion transmission.