Self-Assembled Porous-Silica within N-Doped Carbon Nanofibers as Ultra-flexible Anodes for Soft Lithium Batteries

• Published in: iScience Vol. 16; pp. 122 - 132
• Main Authors: Aboalhassan, Ahmed A., Yan, Jianhua, Zhao, Yun, Dong, Keqi, Wang, Xiao, Yu, Jianyong, Ding, Bin
• Format: Journal Article
• Language: English
• Published: United States Elsevier 28.06.2019
• Subjects: Materials Characterization; Nanomaterials; Electrochemical Energy Storage; Porous Material
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2019.05.023

Silica is an attractive anode material for soft lithium batteries owing to its high specific capacity, but it suffers severe problems of large volume change and unstable solid-electrolyte interface. Moreover, it is a challenge to fabricate flexible silica anodes. Here, we report a low-cost and scalable strategy to create flexible anodes of N-doped carbon nanofiber-confined porous silica (p-SiO @N-CNF) by developing a sol-gel electrospinning process followed by carbonization. This approach causes the p-SiO nanoparticles (NPs) to be self-assembled within the N-CNFs, which act like elastomer and electrolyte barrier to accommodate volume changes and to enhance the stability of SiO , whereas the NPs act as soft plasticizer providing strength to the CNF skeletons. Benefiting from the hierarchical structures, the anodes with high p-SiO loadings (>1.6 mg/cm ) exhibit exceptional cycling performance (>1,000 cycles) in terms of bending, current rate, and capacity. Moreover, the batteries remain stable when discharging at 0.5 C and charging at 2 C.