Pre-strain accommodation enabled multi-dimensionally and hierarchically elastomeric MoSe2/MXene and AC/MXene electrodes for stretchable sodium ion capacitors

Stretchable supercapacitors with simultaneously high energy/power densities and long life can enrich in-tegrated power options for ever-increasing wearable electronics. However, supercapacitors with high electrochemical performances while maintaining high stretchability are still challenging. Herein, we report stretchable sodium ion capacitors (S-SICs) based on multi-dimensionally and hierarchically elastomeric composite electrodes, and stretchable high voltage gel polymer electrolyte (3.0 V). The elastomeric com-posite electrode is constructed by stretchable 3D electrospun polyurethane (PU) fibrous mat and conductive 1D Ag nanowire network. 2D MoSe2/MXene and 3D AC/MXene as anodic and cathodic materials are em-bedded in this conductive and stretchable mat. This hierarchical structure enables multi-dimensional conductive connections under tensile condition. The pre-strain treatment on PU fibrous mat further in-creases the relatively stretching distance before losing conductive connection among hierarchical compo-nents. The electrodes exhibit superior sodium ion storage performances (420 mAh g(-1) at 5 A g(-1)), as well as good stretchability and stability (95% after 1000 cycles at 2 A g(-1)). Based on this, the S-SICs with high operating voltage demonstrate high energy/power densities (max. 5.44 mWh cm(-3), 493.55 mW cm(-3)) and good stretchability. This prototypical exhibition of S-SICs indicates a promising design direction of stretchable supercapacitors with high electrochemical performances and tolerance of stretchability. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

In this study, stretchable sodium ion capacitors (S-SICs) based on multi-dimensionally and hierarchically elastomeric composite electrodes and stretchable high voltage gel polymer electrolyte were developed. The S-SICs demonstrated high energy/power densities, good stretchability, and stability.