Understanding Solid-State Synthesis of Layered Oxide Cathodes by Operando Synchrotron Characterization

The chemical and structural transformations during solid-state synthesis are crucial for developing cost-effective, durable, and high-energy inorganic battery cathodes. However, the thermodynamic and mechanic origins and their effects on synthetic reactions are yet to be fully elucidated. In this work, using a manganese (Mn)-rich precursor specifically targeted for cost-effective cathodes, we decoupled the distinct contributions of thermodynamic parameters in the solid-state synthesis of P2-type Mn-rich layered oxide cathodes for sodium-ion batteries. By utilizing <i>operando</i> synchrotron X-ray diffraction, full field 3D transmission X-ray tomography, high-resolution transmission electron microscopy, and density functional theory calculations, we identified the key reaction pathways that governing the transformation during solid-state synthesis. These pathways ultimately affect the crystallite size, morphology, and electrochemical properties of the resultant layered oxide materials.<br/><br/>Reference:<br/>1. Solid-state synthesis of Mn-rich layered oxide cathodes for sodium-ion batteries, Wenhua Zuo, Guiliang Xu*, Khalil Amine*, <i>et al.</i> 2024, in preparation.<br/>2. Microstrain screening towards defect-less layered transition metal oxide cathodes, Wenhua Zuo, Guiliang Xu*, Khalil Amine*, <i>et al.</i> Nat. Nanotechnol. 2024, Accepted.<br/>3. Layered Oxide Cathodes for Sodium-Ion Batteries: Storage Mechanism, Electrochemistry, and Techno-economics, Wenhua Zuo, <i>et al.</i> Acc. Chem. Res., 2023, 56, 284.<br/>4. Native lattice strain induced structural earthquake in sodium layered oxide cathodes, Guiliang Xu, <i>et al.</i> Nat. Commun., 2022, 13, 436.<br/>5. Engineering Na⁺-layer spacings to stabilize Mn-based layered cathodes for sodium-ion batteries, Wenhua Zuo, <i>et al.</i> Nat. Commun., 2021, 12, 4903.