Mixed‐phase WO <sub>3</sub> Cocatalysts on Hierarchical Si‐based Photocathode for Efficient Photoelectrochemical Li Extraction
Jiang Li, Yanhong Lyu, Aibin Huang, Jianyun Zheng, Chao Xie, Xun Cao, Shuangyin Wang
Abstract
Abstract Photoelectrochemical lithium (Li) extraction can be expected to provide a useful recycle of Li + from waste Li‐containing battery, but the process is limited by the photocathodes with poor Li + absorption and low yield rate. Here, we have designed a hierarchical silicon (Si)‐based photocathode with mixed‐phase tungsten oxide (WO 3 ) cocatalysts for photoelectrochemical Li extraction under 1 sun illumination, achieving a high Li yield rate of ≈223.0 μg cm −2 h −1 and an excellent faradaic efficiency of 91.9 % at 0.0817 V versus Li 0/+ redox couple. The WO 3 cocatalysts with the mixture of amorphous and crystalline phase accelerates the Li + insertion and precipitation and enriches the concentration of Li + at the photocathode surface. This robust photoelectrochemical Li extraction system provides a new insight on designing green and efficient route for cyclic utilization of Li resources in the sustainable energy field.