Details

Autor(en) / Beteiligte

• Xue, Hairong
• Wang, Tao
• Feng, Yaya
• Gong, Hao
• Fan, Xiaoli
• Gao, Bin
• Kong, Yulong
• Jiang, Cheng
• Zhang, Songtao
• Huang, Xianli
• He, Jianping

Titel

Efficient separation of photoexcited carriers in a g-CN-decorated WO nanowire array heterojunction as the cathode of a rechargeable Li-O battery

Ist Teil von

• Nanoscale, 2020-09, Vol.12 (36), p.18742-18749

Erscheinungsjahr

2020

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Utilization of solar energy is very important for alleviating the global energy crisis; however, solar-to-electric energy conversion in a compact battery is a great challenge. High charging overpotential of conventional aprotic Li-O 2 batteries still restricts their practical application. Herein, we propose a photo-involved rechargeable Li-O 2 battery to not only realize direct solar-to-electric energy conversion/storage but also address the overpotential issue. In this photo-involved battery system, the g-C 3 N 4 -decorated WO 3 nanowire array (WO 3 @g-C 3 N 4 NWA) heterojunction semiconductor is used as both the photoelectrode and oxygen electrode. Upon charging under visible-light irradiation, the photoexcited holes and electrons are in situ generated on the WO 3 @g-C 3 N 4 NWA heterojunction cathode. The fabrication of the heterojunction can distinctly reduce the recombination rate between electrons and holes, while photon-generated carriers are effectively and quickly separated and then migrate under a large current density. The discharge product (Li 2 O 2 ) can be oxidized to O 2 and Li + with a reduced charging voltage (3.69 V) by the abundant photoexcited holes, leading to high energy efficiency, good cycling stability and excellent rate capability. This newly photo-involved reaction scheme could open new avenues toward the design of advanced solar-to-electric energy conversion and storage systems. The efficient separation of photoexcited carriers within the g-C 3 N 4 -decorated WO 3 nanowire array distinctly reduces the charging voltage and enhances the cycle performance of the photo-involved Li-O 2 battery.