Functional materials

Synthesis–Structure–Property Relationships in Li- and Mn-rich Layered Oxides

PhD: Ashok S. Menon, Uppsala University (2021)

This project examined how synthetic conditions affect the structural and electrochemical properties of Li- and Mn-rich layered oxides—high-capacity, cost-effective materials that hold promise as positive electrodes for next-generation Li-ion batteries. The research combined diffraction, spectroscopy, and magnetic measurements to explore the relationship between synthesis route, crystal structure, and electrochemical response.

By comparing solid-state and sol-gel synthesis, the work showed how differences in cation ordering, stacking faults, and particle morphology lead to distinct material properties. The studies revealed that compounds such as Li1.2Mn0.54Ni0.13Co0.13O2 can form either single- or multi-phase structures depending on synthesis conditions, and that many of these compositions are metastable under standard preparation environments.

A supercell-based structure model was proposed to better describe the complex crystallography of Li- and Mn-rich oxides, integrating features across multiple length scales. Together, these insights established key structure–property relationships that inform the rational design of stable, high-performance cathode materials for advanced lithium-ion batteries.

Ashok Sreekumar Menon graduated with an MSc in Materials Science and Engineering from Delft University of Technology in 2017, specialising in energy storage materials for sustainable development. His master’s thesis focused on lithium and sodium metal anodes for batteries, investigating dendrite formation and mitigation strategies. He developed a three-dimensional porous nickel scaffold via electrodeposition and studied its electrochemical performance, including the effects of atomic layer deposition on lithium cycling behaviour.