Electrochemical Systems for Lithium-Oxygen Batteries

Lithium–oxygen batteries operate by oxidising lithium metal at the anode and reducing oxygen at the cathode to form lithium peroxide (Li₂O₂) during discharge, with the reverse reaction during charge. This system offers one of the highest theoretical energy densities among rechargeable batteries, making it attractive for electric vehicles and grid-scale storage. Key challenges include high charge–discharge overpotentials, insulating discharge products that clog porous electrodes, parasitic reactions driven by reactive oxygen species, and instability of conventional electrolytes. Advances in electrode architecture, electrolyte composition and catalytic interfaces aim to lower energy losses, promote uniform Li₂O₂ formation and decomposition, and suppress side reactions. Recent efforts focus on atomically precise catalysts, redox mediators and engineered cathode surfaces to improve round-trip efficiency, cycle life and operational safety while maintaining compatibility with practical cell configurations.

Research from Nature Portfolio

Recent studies have demonstrated the power of single-atom catalysts to regulate Li₂O₂ morphology and reaction pathways. One approach embeds isolated cobalt atoms within nitrogen-rich carbon nanosheets, maximising active site exposure and enabling uniform nucleation of nano-sized Li₂O₂ during oxygen reduction. This design yields greatly enhanced redox kinetics, reduces charge–discharge polarisation to around 0.40 V and supports over 260 stable cycles at moderate current densities. Theoretical simulations reveal that cobalt–nitrogen coordination dramatically strengthens the affinity for key intermediates, tuning peroxide size and distribution.

A complementary strategy employs a polymer-encapsulation method to stabilise single cobalt atom sites on a conductive support. The resulting catalyst directs Li₂O₂ growth into micrometre-sized flower-like structures via a one-electron pathway and promotes efficient peroxide decomposition. Cells using this catalyst achieve a high round-trip efficiency of 86.2 % and continuous operation exceeding 218 days, outperforming benchmark platinum-based systems and illustrating the synergy between isolated metal atoms and tailored supports.

Electrochemical Systems for Lithium-Oxygen Batteries publication trend

The graph below shows the total number of articles in electrochemical systems for lithium-oxygen batteries across all publications each year (not limited to Nature Index journals).

Technical terms

Oxygen reduction reaction (ORR): The electrochemical process at the cathode where O₂ is reduced, typically forming LiO₂ or Li₂O₂ in Li–O₂ cells.

Oxygen evolution reaction (OER): The reverse electrochemical process during charging, in which Li₂O₂ is oxidised back to O₂ and lithium ions.

Overpotential: The extra voltage beyond the thermodynamic potential required to drive ORR or OER at a practical rate.

Single-atom catalyst: A catalyst in which isolated metal atoms are dispersed on a support, maximising atomic efficiency and tuning reaction pathways.

Redox mediator: A soluble species that shuttles electrons between electrode and reactants, lowering activation barriers and reducing overpotentials.

Round-trip efficiency: The ratio of energy output during discharge to energy input during charge, reflecting overall energetic losses.

References

1. Atomically dispersed cobalt catalyst anchored on nitrogen-doped carbon nanosheets for lithium-oxygen batteries. Nature Communications (2020).
2. Tuning lithium-peroxide formation and decomposition routes with single-atom catalysts for lithium–oxygen batteries. Nature Communications (2020).
3. Atomically Dispersed Ruthenium Catalysts with Open Hollow Structure for Lithium–Oxygen Batteries. Nano-Micro Letters (2023).
4. Mechanism and performance of lithium–oxygen batteries – a perspective. Chemical Science (2017).
5. Dual redox catalysts for oxygen reduction and evolution reactions: towards a redox flow Li–O 2 battery. Chemical Communications (2015).