Peroxo Species Formed in the Bulk of Silicate Cathodes.

ABSTRACT: Oxygen redox in Li-rich oxides may boost the energy density of lithium-ion batteries by incorporating oxygen chemistry in solid cathodes. However, oxygen redox in the bulk usually entangles with voltage hysteresis and oxygen release, resulting in a prolonged controversy in literature on oxygen transformation. Here, we report spectroscopic evidence of peroxo species formed and confined in silicate cathodes amid oxygen redox at high voltage, accompanied by Co²⁺ /Co³⁺ redox dominant at low voltage. First-principles calculations reveal that localized electrons on dangling oxygen drive the O-O dimerization. The covalence between the binding cation and the O-O dimer determines the degree of electron transfer in oxygen transformation. Dimerization induces irreversible struct

SUBMITTER: Chen Z 

PROVIDER: S-EPMC8251627 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature