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

Ahmed A Aboalhassan; Jianhua Yan; Yun Zhao; Keqi Dong; Xiao Wang; Jianyong Yu; Bin Ding

doi:10.1016/j.isci.2019.05.023

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

iScience. 2019 Jun 28:16:122-132. doi: 10.1016/j.isci.2019.05.023. Epub 2019 May 23.

Authors

Ahmed A Aboalhassan¹, Jianhua Yan², Yun Zhao³, Keqi Dong³, Xiao Wang⁴, Jianyong Yu⁵, Bin Ding⁶

Affiliations

¹ Key Laboratory of Textile Science & Technology, Ministry of Education, Donghua University, Shanghai 201620, China; State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China.
² Key Laboratory of Textile Science & Technology, Ministry of Education, Donghua University, Shanghai 201620, China; Innovation Center for Textile Science and Technology, Donghua University, Shanghai 200051, China. Electronic address: yanjianhua@dhu.edu.cn.
³ Key Laboratory of Textile Science & Technology, Ministry of Education, Donghua University, Shanghai 201620, China.
⁴ State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China.
⁵ Innovation Center for Textile Science and Technology, Donghua University, Shanghai 200051, China.
⁶ Innovation Center for Textile Science and Technology, Donghua University, Shanghai 200051, China. Electronic address: binding@dhu.edu.cn.

Abstract

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-SiO₂@N-CNF) by developing a sol-gel electrospinning process followed by carbonization. This approach causes the p-SiO₂ 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 SiO₂, whereas the NPs act as soft plasticizer providing strength to the CNF skeletons. Benefiting from the hierarchical structures, the anodes with high p-SiO₂ loadings (>1.6 mg/cm²) 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.

Keywords: Electrochemical Energy Storage; Materials Characterization; Nanomaterials; Porous Material.