Layered H₂Ti₆O₁₃‐Nanowires: A New Promising Pseudocapacitive Material in Non‐Aqueous Electrolyte

Layered H 2 Ti 6 O 13 ‐nanowires are prepared using a facile hydrothermal method and their Li‐storage behavior is investigated in non‐aqueous electrolyte. The achieved results demonstrate the pseudocapacitive characteristic of Li‐storage in the layered H 2 Ti 6 O 13 ‐nanowires, which is because of the typical nanosize and expanded interlayer space. The as‐prepared H 2 Ti 6 O 13 ‐nanowires have a high capacitance of 828 F g −1 within the potential window from 2.0 to 1.0 V (vs. Li/Li + ). An asymmetric supercapacitor with high energy density is developed successfully using H 2 Ti 6 O 13 ‐nanowires as a negative electrode and ordered mesoporous carbon (CMK‐3) as a positive electrode in organic electrolyte. The asymmetric supercapacitor can be cycled reversibly in the voltage range of 1 to 3.5 V and exhibits maximum energy density of 90 Wh kg −1 , which is calculated based on the mass of electrode active materials. This achieved energy density is much higher than previous reports. Additionally, H 2 Ti 6 O 13 //CMK‐3 asymmetric supercapacitor displays the highest average power density of 11 000 W kg −1 . These results indicate that the H 2 Ti 6 O 13 //CMK‐3 asymmetric supercapacitor should be a promising device for fast energy storage.