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

This work systematically studiesthe product self-catalysisof in situ electrochemical cobalt doping of Li2O2 and reveals its potential mechanism for improvingthe performanceof lithium-oxygen (Li-O-2) batteries. Theoreticalcalculations demonstrate that the discharge products contain substitutedand interstitial Co impurities, which serve as active sites to promotethe formation of Li3O4 crystallization, thusswitching the nucleation mechanism from the main discharge productLi(2)O(2) to Li3O4. This Co-dopingbehavior leads to the thermodynamically favorable and dynamicallystable formation of Li3O4 crystals during thedischarge process. Through systematic investigation of the structural,energetic, electronic, diffusive, and catalytic properties of theCo-doped Li2O2 and Li3O4 compounds, we found that Li3O4 has bettercharge/mass transport and a lower overpotential for the Li3O4 formation/decomposition reaction. Consequently, thiswork elucidates that Co doping provides a simple and effective approachfor increasing the proportion of Li3O4, whichcan significantly improve the Li-O-2 battery performance.

Automated summary

This study systematically investigates the self-catalytic effect of in-situ electrochemical cobalt doping of Li2O2 and reveals its potential mechanism for enhancing the performance of lithium-oxygen batteries. Theoretical calculations show that Co impurities in the discharge products serve as active sites to promote the formation of Li3O4, switching the nucleation mechanism. Through a comprehensive investigation of the properties of Co-doped Li2O2 and Li3O4 compounds, it is found that Li3O4 exhibits better charge/mass transport and lower overpotential, leading to improved battery performance.