Realizing Formation and Decomposition of Li2O2 on Its Own Surface with a Highly Dispersed Catalyst for High Round-Trip Efficiency Li-O2 Batteries

• Published in: iScience Vol. 14; pp. 36 - 46
• Main Authors: Song, Li-Na, Zou, Lian-Chun, Wang, Xiao-Xue, Luo, Nan, Xu, Ji-Jing, Yu, Ji-Hong
• Format: Journal Article
• Language: English
• Published: Elsevier 26.04.2019
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2019.03.013

The rapid and effective formation and decomposition of Li2O2 during cycling is crucial to solve the problems associated with the practical limitation of lithium-oxygen (Li-O2) batteries. In this work, a highly dispersed electrocatalyst with Ru nanoclusters inside the special organic molecular cage (RuNCs@RCC3) through a reverse double-solvent method for Li-O2 batteries has been proposed for the first time. This RuNCs@RCC3 shows an effective catalyst enabling reversible formation and decomposition of the Li2O2 at the interface between the Li2O2 and the liquid electrolyte, rather than the sluggish solid-solid interface reactions on commonly used solid catalysts. As a result, the Li-O2 cells with RuNCs@RCC3 show enhanced electrochemical performance, including low overpotential (310 mV at a current density of 100 mA g-1), high specific capacity (15,068 mAh g-1), good rate capability (1,800 mAh g-1 at a current density of 2.8 A g-1), and especially superior cycle stability up to 470 cycles.The rapid and effective formation and decomposition of Li2O2 during cycling is crucial to solve the problems associated with the practical limitation of lithium-oxygen (Li-O2) batteries. In this work, a highly dispersed electrocatalyst with Ru nanoclusters inside the special organic molecular cage (RuNCs@RCC3) through a reverse double-solvent method for Li-O2 batteries has been proposed for the first time. This RuNCs@RCC3 shows an effective catalyst enabling reversible formation and decomposition of the Li2O2 at the interface between the Li2O2 and the liquid electrolyte, rather than the sluggish solid-solid interface reactions on commonly used solid catalysts. As a result, the Li-O2 cells with RuNCs@RCC3 show enhanced electrochemical performance, including low overpotential (310 mV at a current density of 100 mA g-1), high specific capacity (15,068 mAh g-1), good rate capability (1,800 mAh g-1 at a current density of 2.8 A g-1), and especially superior cycle stability up to 470 cycles.