Silicon Carbide as a Protective Layer to Stabilize Si-Based Anodes by Inhibiting Chemical Reactions

• DOI: 10.1021/acs.nanolett.9b01492
• Publication Date: 2019-07-01T22:04:41Z
• Authors: Chunhui Yu; Xiao Chen; Zhexi Xiao; Chao Lei; Chenxi Zhang; Xianqing Lin; Boyuan Shen; Rufan Zhang; Fei Wei
• Keywords: 02 engineering and technology; 0210 nano-technology; 7. Clean energy

Developing a practical silicon-based (Si-based) anode is precondition for high-performance lithium-ion batteries. However, the chemical reactivity of Si renders it liable to be consumed, which must completely understood used in battery systems. Here, fresh and fundamental mechanism proposed rapid failure Si-based materials. Silicon can chemically react with lithium hexafluorophosphate (LiPF6) constantly generate hexafluorosilicate (Li2SiF6) aggregates during cycling. In addition, nanocarbon coated on silicon acts as catalyst accelerate such detrimental reactions. By taking advantage high strength toughness carbide (SiC), SiC layer introduced between inner outer carbon layers inhibit formation Li2SiF6. The side reaction rate decreases significantly due increase activation energy reaction. Si@SiC@C maintains specific capacity 980 mAh g–1 at current density 1 A after 800 cycles an initial Coulombic efficiency over 88.5%. This study will contribute improved design Li-ion