Micro/nano-wrinkled elastomeric electrodes enabling high energy storage performance and various form factors

Abstract

Stretchable elastomer-based electrodes are considered promising energy storage electrodes for next-generation wearable/flexible electronics requiring various shape designs. However, these elastomeric electrodes suffer from the limited electrical conductivity of current collectors, low charge storage capacities, poor interfacial interactions between elastomers and conductive/active materials, and lack of shape controllability. In this study, we report hierarchically micro/nano-wrinkle-structured elastomeric electrodes with notably high energy storage performance and good mechanical/electrochemical stabilities, simultaneously allowing various form factors. For this study, a swelling/deswelling-involved metal nanoparticle (NP) assembly is first performed on thiol-functionalized polydimethylsiloxane (PDMS) elastomers, generating a micro-wrinkled structure and a conductive seed layer for subsequent electrodeposition. After the assembly of metal NPs, the conformal electrodeposition of Ni and NiCo layered double hydroxides layers with a homogeneous nanostructure on the micro-wrinkled PDMS induces the formation of a micro/nano-wrinkled surface morphology with a large active surface area and high electrical conductivity. Based on this unique approach, the formed elastomeric electrodes show higher areal capacity and superior rate capability than conventional elastomeric electrodes while maintaining their electrical/electrochemical properties under external mechanical deformation. This notable mechanical/electrochemical performance can be further enhanced by using spiral-structured PDMS (stretchability of ~500%) and porous-structured PDMS (areal capacity of ~280 μAh cm−2).