Boosting lithium storage performance of Si nanoparticles via thin carbon and nitrogen/phosphorus co-doped two-dimensional carbon sheet dual encapsulation

• 作者: Cheng-Zhi Ke Fang Liu Zhi-Ming Zheng He-He Zhang Meng-Ting Cai Miao Li Qi-Zhang Yan Hui-Xin Chen Qiao-Bao Zhang
• 来源期刊: 稀有金属（英文版）
• 年，卷（期）: 2021,（6）
• 所属期刊栏目: MICRO/NANOSTRUCTURED ELECTRODE MATERIALS FOR ELECTROCATALYSIS AND BATTERY
• 页码范围: 1347-1356
• 页数: 10页
• 语种: 英文

摘要

Silicon (Si) is a promising anode candidate for next-generation lithium-ion batteries (LIBs),but it suffers from poor electronic conductivity and dramatic volume variation during cycling,which poses a critical challenge for stable battery operation.To mitigate these issues simultaneously,we propose a "double carbon synergistic encapsulation" strategy,namely thin carbon shell and nitrogen/phosphorus co-doped two-dimensional (2D) car-bon sheet dual encapsulate Si nanoparticles (denoted as 2D NPC/C@Si).This double carbon structure can serve as a conductive medium and buffer matrix to accommodate the volume expansion of Si nanoparticles and enable fast electron/ion transport,which promotes the formation of a stable solid electrolyte interphase film during cycling.Through structural advantages,the resulting 2D NPC/C@Si electrode demonstrates a high reversible capacity of 592 mAh·g-1 at 0.2 A·g-1 with 90.5％ excellent capacity retention after 100 cycles,outstanding rate capability (148 mAh·g-1 at 8 A·g-1),and superior long-term cycling sta-bility (326 mAh·g-1 at 1 A·g-1 for 500 cycles,86％capacity retention).Our findings elucidate the development of high-performance Si@C composite anodes for advanced LIBs.