Given that most oxygen redox based layered oxides suffer from drastic hysteretic-oxygen capacities, Geon-Hee Yoon, Sojung Koo, Seung-Ho Yu and Duho Kim suggest additional stable phase during the oxygen redox for Al incorporated Li excessed Na layered oxide for high‐energy‐density cathodes in sodium‐ion batteries with sensitively controlling the oxygen participation upon cycling. (DOI: 10.1002/aenm.202103384)

Considering anisotropy is significant for Ni–Mn binary layered oxides, Na_1-x[Mn_1/2Ni_1/2]O₂ is reinvestigated by Duho Kim, Maenghyo Cho, Shidong Park, Myungkyu Kim and Hyungjun Kim in article number 24290-24298, adjusting the shape of the secondary particle to alleviate the impact of the anisotropic distortion in order to enhance cycle stability with oxygen redox and fast charging for further advances in LIBs and even SIBs.

In order to elucidate the oxygen-redox reactions in Na-based transition metal layered oxides, Na_1-x[Mn_1/2Fe_1/2]O₂ is reinvestigated by Duho Kim, Maenghyo Cho, Myungkyu Kim and Hyungjun Kim in article number 15179-15187, utilizing the veiled oxygen redox reaction in representative abundant Na_x[Mn_1-yFe_y]O₂ binary oxides to overcome the intrinsic low energy density of the sodium-ion battery cathodes.

Inspired by in‐depth understanding of the Li₂MnO₃ redox mechanism, Na(Li_1/3Mn_2/3)O₂ operated by anionic redox reactions (O²⁻/O⁻ : lone‐pair O) is rationally designed by Maenghyo Cho, Kyeongjae Cho, and Duho Kim in article number 1701788 for high‐energy‐density cathodes in sodium‐ion batteries (SIBs), enabling new Na(Li_1/3M_2/3)O₂ analogues (M: transition metals featuring stabilized M⁴⁺) to break the energy‐density limit of cathodes for SIBs.