Hybrid material offers supercapacitor with unprecedented energy storage, cycle life, strength, and flexibility for next-generation cell phones, displays and wearables

UCF researchers have invented novel materials that enable next-generation supercapacitors to outperform current state-of-the-art energy storage technologies, including lithium thin-film batteries, porous graphene, electrolytic capacitors, and recently developed MXenes and metallic 1T-MoS2. The new hybrid one-dimensional/two-dimensional (1D/2D) core/shell nanowires enable manufacturers to produce flexible supercapacitors with exceptional charge−discharge endurance (for example, 100 percent capacitance retention after 30,000 cycles of charging and discharging).

Though lithium batteries power almost all electronic devices, their low energy density, inability to charge quicker, and use of toxic lithium metal prevent them from being the world’s sustainable energy storage devices. Emerging supercapacitor technology, such as 2D transition-metal dichalcogenides (TMDs), promises to be a viable alternative to batteries. Yet, current options are costly, provide limited cyclic stabilities, and are mechanically feeble. The UCF hybrid nanowire invention, however, offers a low-cost, non-toxic solution with unprecedented specific capacitance, keen flexibility and prolonged cyclic stability.

Technical Details

The invention comprises materials and methods for fabricating arrays of 1D/2D core/shell nanowire supercapacitors with excellent strength and flexibility, high energy density, and superb charge-discharge capabilities. For example, vertically aligned nanowires provide enhanced surface areas for improved adsorption/intercalation of electrolyte ions. Conductive nanowire cores of 1D hexagonal tungsten trioxide (h-WO3) provide efficient carrier transports and capacitive 2D tungsten disulfide (WS2) nanowire shells facilitate ion absorption from electrolytes. The interfaces of the core/shell and nanowire/current collector are chemically self-assembled without any binders or extra materials; thus, ensuring structural integrity. All components are converted from one identical material, enabling one-body structures with remarkable mechanical stability.

Benefits

• Simple, cost-effective fabrication method
• Environmentally friendly and non-toxic materials
• Facilitates much higher capacitance than batteries and other 2D material-based capacitors
• High energy density
• Unprecedented cycle life (could be charged 30,000 times)
• Excellent mechanical bendability

Applications

• Next-generation flexible and wearable technologies such as e-textiles, flexible cell phones, and displays