Abstract
Controllable anionic redox for a transformational increase in the energy density is the pursuit of next generation Li-ion battery cathode materials. Its activation mechanism is coupled with the local coordination environment around O, which posts experimental challenges for control. Here, the tuning capability of anionic redox is shown by varying O local environment via experimentally controlling the density of stacking faults in Li2MnO3, the parent compound of Li-rich oxides. By combining computational analysis and spectroscopic study, it is quantitatively revealed that more stacking faults can trigger smaller Li-O-Li bond angles and larger Li-O bond distance in local Li-rich environments and subsequently activate oxygen redox reactivity, which in turn enhances the reactivity of Mn upon the following reduction process. This study highlights the critical role of local structure environment in tuning the anionic reactivity, which provides guidance in designing high-capacity layered cathodes by appropriately adjusting stacking faults.
Original language | English |
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Article number | 2207904 |
Journal | Advanced Materials |
Volume | 35 |
Issue number | 22 |
DOIs | |
State | Published - Jun 1 2023 |
Funding
This work was financially supported by the National Key R&D Program of China (2022YFB2404400), National Natural Science Foundation of China (Grants: 92263206, 21975006, 22075007, 22002004, and 52002007), “The Youth Beijing Scholars program” (11000022T000000440694), and Beijing Natural Science Foundation (KZ202010005007 and 2222001). Soft X-ray spectroscopy was performed at the BL 8.0.1.1 (iRIXS) endstation at the Advanced Light Source (ALS), a USA DOE Office of Science User Facility at Lawrence Berkeley National Laboratory (LBNL), under DOE contract no. DE-AC02-05CH11231. The neutron studies (at NOMAD) used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by ORNL. This work was financially supported by the National Key R&D Program of China (2022YFB2404400), National Natural Science Foundation of China (Grants: 92263206, 21975006, 22075007, 22002004, and 52002007), “The Youth Beijing Scholars program” (11000022T000000440694), and Beijing Natural Science Foundation (KZ202010005007 and 2222001). Soft X‐ray spectroscopy was performed at the BL 8.0.1.1 (iRIXS) endstation at the Advanced Light Source (ALS), a USA DOE Office of Science User Facility at Lawrence Berkeley National Laboratory (LBNL), under DOE contract no. DE‐AC02‐05CH11231. The neutron studies (at NOMAD) used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by ORNL.
Keywords
- Li-O-Li bond angles
- Li-ion batteries
- LiMnO
- oxygen anion activities
- stacking faults