Facile Synthesis of Micrometer-sized Hierarchical Porous Si@C Anodes for High-Performance Lithium-Ion Batteries [electronic resource]

• Ngôn ngữ: eng
• Ký hiệu phân loại: 620 Engineering and allied operations
• Thông tin xuất bản: Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2021
• Mô tả vật lý: Medium: ED : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 267856
• Chủ đề: 1. 01 coal, lignite, and peat; 2. 25 energy storage; 3. 36 materials science; 4. 37 inorganic, organic, physical, and analytical chemistry; 5. Humic acid, porous silicon, magnesiothermic reduction, hierarchical structure, lithium-ion batteries

Tóm tắt

 Extensive studies have been conducted to determine if replacing graphite anodes with silicon is feasible since silicon possesses a high capacity and is an abundant resource
  however, Si anodes suffer significant volume changes during cycling, which pulverizes its structure and subsequently causes rapid capacity fading. We used SiO2 nanoparticles (nSiO2) and low-cost coal-derived humic acid as a feedstock to synthesize high performance Si-C anodes for Li-ion Batteries through spray drying, calcination, and magnesiothermic reductions. Our Si-C anodes features micrometer-sized porous Si coated with a graphitized carbon shell (mpSi@C). The hierarchical graphitized carbon shell and porous silicon structure relieve the mechanical stress of the Si phase upon cycling, which stabilizes the structure. This mpSi@C composite design allows for a high initial discharge capacity of 2199.9 mAh g-1 at 0.1 A g-1 and a cycling performance of 68% capacity retention after 100 cycles at 1.0 A g-1. The multipoint contact between the Si anode and C structure allows for a remarkable performance rate of 566.3 mAh g-1 at 5.0 A g-1.