Harvesting Air and Light Energy via 'All-in-One' Polymer Cathodes for High-Capacity, Self-Chargeable, and Multimode-Switching Zinc Batteries

摘要

Aqueous rechargeable Zinc (Zn)-polymer batteries are promising alternatives to prevalent Li-ion cells in terms of cost, safety, and rate capability but they suffer from limited specific capacity in addition to poor environmental adaptability. Herein, air and light are successfully utilized from external environments in single near-neutral two-electrode Zn batteries to enable remarkably improved electrochemical performance, fast self-charging, and switchable multimode-operation from Zn-polymer to Zn-air cells. This system is enabled by a well-designed polyaniline-nanorod-array based "all-in-one" cathode combining reversible redox capability, oxygen reduction activity, and photothermal-responsiveness. The initiative design allows perfect integration of multiple energy harvesting from ambient "air" and light, energy conversion, and storage in one single cathode. Thus, it can act as an efficient light-assisted electrically-rechargeable Zn-polymer cell featuring the highest specific capacity of 430.0 mAh g(-1) among all existing polymer cathodes. Without external power sources, it can be self-charged to deliver a high discharging capacity of 363.1 mAh g(-1) by concurrently harvesting chemical energy from air and light energy for only 20 min. It can also switch to a light-responsive Zn-air battery mode to surmount the output capacity limit of Zn-polymer battery mode for continued electricity supply.