Electrochemical behavior of Ag nanoparticle-incorporated Li4Ti5O12 nanofibers as Li-ion battery anodes under visible light exposure

To gain insight into the light-induced plasmonic effect on metal nanoparticle-doped Li4Ti5O12 nanofibers (LTO NFs), we used Ag-LTO NFs as an anode material for solar Li-ion battery-based coin cells. The efficient incor-poration of silver nanoparticles into LTO NFs improved electrochemical performance by shortening the elec-tronic pathway and increasing conductivity in the presence of light. To better understand this process, in situ electrochemical studies were performed using a perforated coin cell with its anode subjected to light exposure. The studies revealed a synergistic effect of light and Ag-LTO NFs that led to both light-induced and electro-chemical Li+ insertion, which in turn resulted in an enhanced Li-extraction and insertion speed. Overall, better reversibility and a 1.5-fold improvement in the conductivity of the Ag-LTO NFs under light irradiation were achieved. Our work opens an avenue for promising light-responsive plasmonic heterojunction materials toward a sustainable response to the increasing demand for high-power energy storage.