Facile and green synthesis of nanocellulose with the assistance of ultraviolet light irradiation for high-performance quasi-solid-state zinc-ion batteries

Benefiting from excellent mechanical properties, large surface area, rich hydroxyl groups, good sustainability, etc., nanocellulose is highly promising for various applications. However, intense chemical treatment and long-term processing are usually required to fabricate nanocellulose. Herein, a new synthesis method of nanocellulose is developed by using ultraviolet light irradiation-assisted delignification and subsequent sonification. This method is more cost-effective, time-saving, and environmentally benign compared to most of previously reported synthesis methods of nanocellulose. The obtained nanocellulose contains a small amount of lignin, which is unfavorable for high-temperature stability and optimal transparency. However, a small amount of lignin is beneficial to mechanical properties and in-water stability. With this nanocellulose, flexible MnO2 cathode film and hydrogel electrolyte are constructed and a quasisolid-state zinc-ion battery is assembled. The battery exhibits 233.3 mAh g(-1) after 1000 cycles at 1 A g(-1) and 20 degrees C. And more than half of that capacity can be maintained at -20 degrees C. The battery also possesses great rate capability and good endurance to external forces. This work provides new insights into the syn- thesis and application of nanocellulose. (C) 2022 Elsevier Inc. All rights reserved.