Battery (electricity)

Engineering

Chemical physics

Oxide

Transmission electron microscopy

Electrochemistry

Metallurgy

Materials science

Chromatography

Cathode

Graphene

Differential scanning calorimetry

Electron energy loss spectroscopy

Power (physics)

Chemical engineering

Physical chemistry

Thermodynamics

Physics

Nanotechnology

Organic chemistry

Oxygen

Analytical Chemistry (journal)

Scanning transmission electron microscopy

Chemistry

Electrode

Thermal runaway

Advanced Functional Materials

LiCoO 2 is a prime example of widely used cathodes that suffer from the structural/thermal instability issues that lead to the release of their lattice oxygen under nonequilibrium conditions and safety concerns in Li‐ion batteries. Here, it is shown that an atomically thin layer of reduced graphene oxide can suppress oxygen release from Li x CoO 2 particles and improve their structural stability. Electrochemical cycling, differential electrochemical mass spectroscopy, differential scanning calorimetry, and in situ heating transmission electron microscopy are performed to characterize the effectiveness of the graphene‐coating on the abusive tolerance of Li x CoO 2 . Electrochemical cycling mass spectroscopy results suggest that oxygen release is hindered at high cutoff voltage cycling when the cathode is coated with reduced graphene oxide. Thermal analysis, in situ heating transmission electron microscopy, and electron energy loss spectroscopy results show that the reduction of Co species from the graphene‐coated samples is delayed when compared with bare cathodes. Finally, density functional theory and ab initio molecular dynamics calculations show that the rGO layers could suppress O 2 formation more effectively due to the strong CO cathode bond formation at the interface of rGO/LCO where low coordination oxygens exist. This investigation uncovers a reliable approach for hindering the oxygen release reaction and improving the thermal stability of battery cathodes.

Anti‐Oxygen Leaking LiCoO <sub>2</sub>

Anti‐Oxygen Leaking LiCoO 2

Anti‐Oxygen Leaking LiCoO ₂