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The Role of Self-Catalysis Induced by Co Doping in Nonaqueous Li-O 2 Batteries.

Lixin XiongNeil Qiang SuWei-Hai Fang
Published in: The journal of physical chemistry letters (2023)
This work systematically studies the product self-catalysis of in situ electrochemical cobalt doping of Li 2 O 2 and reveals its potential mechanism for improving the performance of lithium-oxygen (Li-O 2 ) batteries. Theoretical calculations demonstrate that the discharge products contain substituted and interstitial Co impurities, which serve as active sites to promote the formation of Li 3 O 4 crystallization, thus switching the nucleation mechanism from the main discharge product Li 2 O 2 to Li 3 O 4 . This Co-doping behavior leads to the thermodynamically favorable and dynamically stable formation of Li 3 O 4 crystals during the discharge process. Through systematic investigation of the structural, energetic, electronic, diffusive, and catalytic properties of the Co-doped Li 2 O 2 and Li 3 O 4 compounds, we found that Li 3 O 4 has better charge/mass transport and a lower overpotential for the Li 3 O 4 formation/decomposition reaction. Consequently, this work elucidates that Co doping provides a simple and effective approach for increasing the proportion of Li 3 O 4 , which can significantly improve the Li-O 2 battery performance.
Keyphrases
  • ion batteries
  • solid state
  • quantum dots
  • molecular dynamics
  • density functional theory
  • molecular docking
  • highly efficient
  • crystal structure