An intrinsically stretchable aqueous Zn-MnO2 battery based on microcracked electrodes for self-powering wearable electronics

Abstract

Stretchable batteries are indispensable energy storage devices to power emerging wearable electronics in soft form factors. In contrast to commonly employed engineering approaches to mitigate strains through structural design, the intrinsically stretchable devices naturally exhibit skin-like mechanical deformability by using all compliant building components. Currently, the intrinsically stretchable battery often shows a significant trade-off between electrochemical performances and mechanical deformability. Here, we introduce a low-cost and scalable approach to create an intrinsically stretchable aqueous battery featuring the deployment of state-of-art battery materials and binders. The compliant current collector, in the form of a bilayer silver nanowire/carbon nanotube nanocomposites, demonstrates excellent mechanical stretchability and electrochemical stability. The microcracked electrode layer retains stable charge transport and excellent electrochemical activity under large mechanical deformations through firm attachment to the bilayer current collector. A stretchable Zn-MnO2 cell in a sandwiched configuration is assembled exhibiting high specific capacity (>200 mAh g−1 at 100 mA g−1), excellent capacity retention of ∼90% over 100 cycles, large stretchability up to 100% strain, and durability against repetitive mechanical deformations. The practical suitability is demonstrated by a stand-alone electronic system conformably mounted on the wrist, in which an LED array is powered by a pair of stretchable Zn-MnO2 batteries.