Welcome to Tong Li's Chair - Atomic-scale Characterisation

My current research focus is to develop correlative multimodal approaches centered around atom probe tomography to reveal atomic-scale structural and compositional changes at electrolyte/electrode interfaces. I am keen to provide mechanistic insights into how battery interfaces work.  Our goal is to optimize electrode/electrolyte interfaces and interphases for lithium metal and zinc ion batteries.

I am also interested in designing and fabricating oxide and alloy nanoparticles for water electrolyzers and fuel cells. We aim to provide a fundamental understanding of elementary processes occurring at the electrode/electrolyte interfaces during electrocatalytic reactions.

Revealing Dynamic Surface and Subsurface Reconstruction of High-Entropy Alloy Electrocatalysts during the Oxygen Evolution Reaction at the Atomic Scale

High-entropy alloys (HEAs) are promising for oxygen evolution reaction (OER) electrocatalysts, but understanding their surface and subsurface changes during OER is key to improving performance. Our study reveals that the CrMnFeCoNi Cantor alloy undergoes dissolution and complex layer formation during OER, leading to activity deterioration, highlighting the importance of structure–activity–stability relationships in HEAs. Read more...

C. Luan, D. Escalera-López, U. Hagemann, A. Kostka, G. Laplanche, D. Wu, S. Cherevko, T. Li, ACS Catalysis, 14 (2024).

Correlating atomic-scale structural and compositional details of perovskite nanoparticles with activity and stability towards the oxygen evolution reaction

To develop efficient oxygen evolution reaction (OER) electrocatalysts, we used atom probe tomography and transmission electron microscopy to analyze LaCoO₃ and Ca-doped LaCoO₃ surfaces. Our findings reveal that while LaCoO₃ surfaces deteriorate after OER due to the formation of amorphous La(OH)₃, Ca-doped LaCoO₃ shows enhanced OER activity and stability due to increased hydroxide ion intercalation and the appearance of a Co ^3+/4+ redox couple. Read more...

F. Bai, J. Schulwitz, T. Priamushko, U. Hagemann, A. Kostka, M. Heidelmann, S. Cherevko, M. Muhler, T. Li, Journal of Catalysis, 115697 (2024).

Linking Composition, Structure and Thickness of CoOOH to Oxygen Evolution Reaction Activity by Correlative Microscopy,

Our correlative multimodal approach can link local activity with atomic-scale details of structure, morphology and composition of surface species formed during the oxygen evolution reaction (OER). We found that 6 nm β-CoOOH(01-10) layer, grown on [-12-10]-oriented Co, contains more hydroxyl ions and easily reducible CoIII-O sites, exhibiting a higher OER activity than 3 nm thick β-CoOOH(10-13) formed on [02-21]-oriented Co. Read more..

C. Luan, J. Angona, A. BalaKrishnan, M. Corva, P. Hosseini, M. Heidelmann, U. Hagemann, E.B. Tetteh, W. Schuhmann, K. Tschulik, T. Li, Angewandte Chemie International Edition (2023).

Atomic-scale Insights to Morphological, Structural and Compositional Evolution of CoOOH during Oxygen Evoltuion Reaction

We unveil that in situ generated thin ß-CoOOh(0001) layer undergoes dynamic morphological and elemental changes along with (de)incorporation of water molecules and hydroxyl groups during OER, which in turn alters OER perfomance.

C. Luan, M. Corva, U. Hagemann, H. Wang, M. Heidelmann, K. Tschulik, T. Li;  ACS Catalysis 12(2) (2023) 1400-1411.

Atomic-scale Characterisation of (electro-)catalysts and battery materials by atom probe tomography

This perspective provides an overview of recent developments in experimental setups, sample preparation methods and data analysis algorithms for APT.

T. Li, A. Devaraj, N. Kruse; Cell Reports Physical Science 3(12) (2022) 101188.

Direct Detection of Surface Species Formed on Iridium Electrocatalysts during the Oxygen Evolution

We developed an approach to directly examine the oxidation state and surface composition of nanosized Ir electrodes after oxygen evolution reaction (OER). APT reveals compositional changes in the topmost surface and subsurface on various Ir planes during OER.

A. BalaKrishnan, N. Blanc, U. Hagemann, P. Gemagami, K. Wonner, K. Tschulik, T. Li;  Angew Chem Int Ed Engl 60(39) (2021) 21396-21403.

3D atomic-scale imaging of mixed Co-Fe spinel oxide nanoparticles during oxygen evolution reaction

We use atom probe tomography to elucidate the 3D structure of 10 nm sized Co₂ FeO₄ and CoFe2O₄ nanoparticles during oxygen evolution reaction (OER). We reveal nanoscale spinodal decomposition in pristine Co₂FeO₄.

W. Xiang, N. Yang, X. Li, J. Linnemann, U. Hagemann, O. Ruediger, M. Heidelmann, T. Falk, M. Aramini, S. DeBeer, M. Muhler, K. Tschulik, T. Li;  Nature Communications 13(1) (2022) 179.