prepared Li-gradient Li-rich single crystals by extracting LiO from molten salt, showing a voltage attenuation rate of 1.17 mV per cycle 7. Recently, scientists have achieved remarkable results in suppressing voltage fade using some other strategies 7, 8, 9, 10, 11. Although a variety of methods, including bulk doping 3, surface modification 4, and adjusting element compositions 5, 6, have been adopted to restrain voltage fade, none can fundamentally solve it. But Li-rich Mn-based oxides universally manifest a daunting challenge of voltage fade with electrochemical cycling, seriously obstructing its practical applications. Such limitation is foreseen to be transcended by Li-rich Mn-based oxides, which exhibit both M and O redox activities and a high reversible capacity (>250 mA h g −1) 2. The improvement space for traditional cathode materials based on transition metal (M) cationic redox is limited to the gradually approached energy-density ceiling 1. Increasing dependence of electric vehicles and energy-storage systems on high-energy Li-ion batteries pressingly calls for continual developments in the performance of cathode materials. The modulated cathode demonstrates a low voltage decay rate (0.45 millivolt per cycle) and a long cyclic stability. This restrains cation reduction, metal–oxygen bond fracture, and the formation of localized O 2 molecule, which fundamentally inhibits lattice oxygen escape and cation migration. This modulation expands the region in which lattice oxygen contributes capacity by oxidation to oxygen holes and relieves the charge transfer from anionic band to antibonding metal–oxygen band under a deep delithiation. Herein, we modulate the oxygen anionic redox chemistry by constructing Li 2ZrO 3 slabs into Li 2MnO 3 domain in Li 1.21Ni 0.28Mn 0.51O 2, which induces the lattice strain, tunes the chemical environment for redox-active oxygen and enlarges the gap between metallic and anionic bands. But their correlation is not very clear and voltage decay is still a bottleneck.
![3.65 version eutron 3.65 version eutron](https://i1.rgstatic.net/publication/238762460_Coherence_approach_to_neutron_propagation_in_spin_echo_instruments/links/0f3175336b36e6801d000000/largepreview.png)
Oxygen release and irreversible cation migration are the main causes of voltage fade in Li-rich transition metal oxide cathode.