Boosting the reaction kinetics in aprotic lithium-carbon dioxide batteries with unconventional phase metal nanomaterials

作者：Zhou, Jingwen; Wang, Tianshuai; Chen, Lin; Liao, Lingwen; Wang, Yunhao; Xi, Shibo; Chen, Bo; Lin, Ting; Zhang, Qinghua; Ye, Chenliang; Zhou, Xichen; Guan, Zhiqiang; Zhai, Li; He, Zhen; Wang, Gang; Wang, Juan; Yu, Jinli; Ma, Yangbo; Lu, Pengyi; Xiong, Yuecheng; Lu, Shiyao; Chen, Ye; Wang, Bin; Lee, Chun-Sing; Cheng, Jianli^*; Gu, Lin^*; Zhao, Tianshou^*; Fan, Zhanxi^*

来源：PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2022, 119(40): e2204666119.

DOI：10.1073/pnas.2204666119

• unconventional phase
• Ir nanostructures
• reaction kinetics
• electrochemical mechanism
• Li-CO2 battery

Given the high energy density and eco-friendly characteristics, lithium-carbon dioxide (Li-CO2) batteries have been considered to be a next-generation energy technology to promote carbon neutral and space exploration. However, Li-CO2 batteries suffer from sluggish reaction kinetics, causing large overpotential and poor energy efficiency. Here, we observe enhanced reaction kinetics in aprotic Li-CO2 batteries with unconventional phase 4H/face-centered cubic (fcc) iridium (Ir) nanostructures grown on gold template. Significantly, 4H/fcc Ir exhibits superior electrochemical performance over fcc Ir in facilitating the round-trip reaction kinetics of Li+-mediated CO2 reduction and evolution, achieving a low charge plateau below 3.61 V and high energy efficiency of 83.8%. Ex situ/in situ studies and theoretical calculations reveal that the boosted reaction kinetics arises from the highly reversible generation of amorphous/low-crystalline discharge products on 4H/fcc Ir via the Ir-O coupling. The demonstration of flexible Li-CO2 pouch cells with 4H/fcc Ir suggests the feasibility of using unconventional phase nanomaterials in practical scenarios.

• 单位
  清华大学; 中国科学院; 电子科技大学; 1; 中国科学院研究生院