Integrated Electrode-Electrolyte Optimization to Manufacture a Real-Life Applicable Aqueous Supercapacitor with Record-Breaking Lifespan

Abstract. Aqueous supercapacitors (SCs) have been regarded as a promising candidate for commercial energy storage device due to their superior safety, low cost, and environmental benignity. Unfortunately, an age-old challenge of achieving both long electrode lifespan and qualified energy-storage property blocks their practical application. Herein, we develop an electrode-electrolyte integrated optimization strategy to fulfil the real-life device requirements. Electrode optimization simultaneously regulates the nano-morphology and surface chemistry of the tungsten oxide anode, resulting in superior electrochemical performance given by an ideal “bird nest” structure with optimal oxygen vacancy status; the anodes interact with and are protected from dissolution and structural collapse by the rationally designed hybrid electrolyte with optimized pH and facilitated cation desorption behavior. Collaboratively, a record-breaking durability of no capacitive decay after 250,000 cycles is achieved. On the basis of this integrated optimization, the first aqueous pouch SCs with real-life practicability were manufactured by a soft-package encapsulation technique, which can steadily power commercial 3C products such as tablets and smartphones and maintain safely working against extreme conditions. This work demonstrates the possibility of using aqueous energy storage devices with enhanced safety and lower cost to replace the commercial organic counterparts for wide range of daily applications.