Buckled Amorphous Hollow Carbon Spheres: Facile Fabrication, Buckling Process, and Applications as Electrode Materials for Supercapacitors.

Buckled hollow carbon nanospheres (BHCSs) integrate several attractive properties desired for a variety of potential applications. However, the development of a feasible and simple method for preparing BHCS nanoparticles remains a great challenge. Herein, we present a facile strategy for fabricating monodisperse BHCSs via the compression of intact hollow carbon nanospheres (HCSs) with improved mechanical strength. The essence of our strategy lies in the successful preparation of robust HCSs that can sustain large mechanical deformation during compression, based on the introduction of polyvinylpyrrolidone in the synthesis of HCS templates. Both experiments and finite element analyses are conducted to probe the deformation mechanism of buckling, suggesting that the residual stress introduced by pyrolysis of precursors plays a predominant role in the buckling process. Furthermore, the use of BHCSs as high-performance supercapacitors is demonstrated. Our work provides important insights into the engineering of robust amorphous carbon nanomaterials by the template method and mechanical modulation and provides an innovative synthetic strategy for fabricating asymmetric hollow spheres with potential for a diversity of applications.