1.8 V all-solid-state flexible asymmetric microsupercapacitors based on direct-writing electrodes

Increasing the energy density of microsupercapacitors is a key challenge in promoting their practical applications. Accordingly, the construction of asymmetric microsupercapacitors (AMSCs) based on pseudocapacitive materials by increasing the capacitance of devices and widening their working voltage is an effective way to address this challenge. In this work, double-electric-layer-structured pseudocapacitive electrodes were designed and prepared for AMSCs via a one-step direct-writing method. Benefiting from the structural advantages and complementary voltage of the electrodes, AMSCs delivered a wide operating voltage window of up to 1.8 V in a polyvinyl alcohol/LiCl gel electrolyte and showed a high areal capacitance of 42 mF cm^-2, resulting in an outstanding areal energy density of 18.9 μW h cm^-2. This study provides a new approach for developing high-performance microsupercapacitors for portable electronic devices.