LiNiO2 (LNO) is a promising cathode material for next‐generation Li‐ion batteries due to its
exceptionally high capacity and cobalt‐free composition that enables more sustainable and
ethical large‐scale manufacturing. However, its poor cycle life at high operating voltages
over 4.1 V impedes its practical use, thus motivating efforts to elucidate and mitigate LiNiO2
degradation mechanisms at high states of charge. Here, a multiscale exploration of high‐
voltage degradation cascades associated with oxygen stacking chemistry in cobalt‐free …

In article number 2106402, Mark C. Hersam and co-workers show that lattice oxygen loss
plays a critical role in the O3–O1 stacking transition in cobalt-free LiNiO 2 lithium-ion battery
cathodes, which subsequently induces Ni-ion migration and irreversible stacking faults,
microscale electrochemical creep, cracking, and even bending of layers after high-voltage
cycling. By suppressing oxygen evolution, hermetic graphene coatings arrest this
degradation cascade, resulting in substantially improved high-voltage capacity retention.