Biomass-Derived P/N-Co-Doped Carbon Nanosheets Encapsulate Cu3P Nanoparticles as High-Performance Anode Materials for Sodium–Ion Batteries

• Published in: Frontiers in chemistry Vol. 8; p. 316
• Main Authors: Yin, Yanyou, Zhang, Yu, Liu, Nannan, Sun, Bing, Zhang, Naiqing
• Format: Journal Article
• Language: English
• Published: Frontiers Media S.A 05.05.2020
• Subjects: biomass; Chemistry; Cu3P; nanosheets; P/N-co-doped carbon; sodium-ion batteries
• ISSN: 2296-2646; 2296-2646
• DOI: 10.3389/fchem.2020.00316

Biomass-derived approaches have been accepted as a practical way for the design of transitional metal phosphides confined by carbon matrix (TMPs@C) as energy storage materials. Herein, we successfully synthesize P/N-co-doped carbon nanosheets encapsulating Cu 3 P nanoparticles (Cu 3 P@P/N-C) by a feasible aqueous reaction followed by a phosphorization procedure using sodium alginate as the biomass carbon source. Cu-alginate hydrogel balls can be squeezed into two-dimensional (2D) nanosheets through a freeze–drying process. Then, Cu 3 P@P/N-C was obtained after the phosphorization procedure. This rationally designed structure not only improved the kinetics of ion/electron transportation but also buffered the volume expansion of Cu 3 P nanoparticles during the continuous charge and discharge processes. In addition, the 2D P/N co-doped carbon nanosheets can also serve as a conductive matrix, which can enhance the electronic conductivity of the whole electrode as well as provide rapid channels for electron/ion diffusion. Thus, when applied as anode materials for sodium-ion batteries, it exhibited remarkable cycling stability and rate performance. Prominently, Cu 3 P@P/N-C demonstrated an outstanding reversible capacity of 209.3 mAh g −1 at 1 A g −1 after 1,000 cycles. Besides, it still maintained a superior specific capacity of 118.2 mAh g −1 after 2,000 cycles, even at a high current density of 5 A g −1 .