Fully integrated design of a stretchable kirigami-inspired micro-sized zinc–sulfur battery

Abstract

The successful development of flexible and wearable electronic devices has created an ever-increasing demand for electrochemically-efficient flexible/stretchable energy storage devices. 3D kirigami-inspired energy storage devices have recently emerged as a viable option for achieving high strain (stretchability) without compromising electrochemical properties. However, such devices suffer from poor energy and power densities compared to those with 1D-fiber-like and 2D planar configurations. To this end, this study reports the design and fabrication of the first stretchable micro-sized zinc–sulfur (Zn–S) battery with excellent electrochemical properties. The kirigami-inspired quasi-solid-state Zn–S battery possesses notable features such as freeze resistance and exceptional stretchability. Additionally, the battery's stretchability and bendability have been improved by incorporating a polymer-based current collector with low electrical resistivity. The micro-sized Zn–S battery with Ag/silicone composite current collectors offers an energy density of 184.8 mW h g⁻¹ based on the AC-S/Zinc NPs (67.2 mW h g⁻¹ based on the Zn–S cell), deformability (strain) of 200%, a long lifespan with excellent coulombic efficiency, and a discharge capacity retention rate of 90% over 800 cycles. The stretchable Zn–S presents no electrochemical performance degradation over 10 000 cycles of stretching/releasing and an insignificant drop after 10 000 stretching/bending (180°) cycles at 25 °C. The synthesized hydrogel electrolyte endows a minor drop (<10%) in electrochemical behavior after being subjected to 10 000 stretching and bending cycles. The double-sided adhesive current collector makes it possible to fabricate multi-layered kirigami-inspired energy storage devices in serial and parallel configurations to meet stretchable electronics' energy and power requirements.