Energy Futures Lab Lunchtime Seminar Series
As part of the Energy Futures Lab Lunchtime Seminar Series, Heather Au will deliver a seminar entitled ‘Structural influences on the performance and storage mechanisms in hard carbons for sodium-ion batteries’
Sodium-ion batteries have shown potential as a cost-effective successor to lithium-ion batteries, but the performance is still limited by their low energy density and poor cycleability compared with lithium-ion analogues. The development of suitable electrode materials is crucial for the realisation of sodium-ion batteries as a feasible replacement. Disordered carbons, also known as ‘hard carbons’ (i.e. those with some degree of graphitisation but randomly oriented graphitic domains) are considered promising anode materials due to negligible volume change during the sodiation/desodiation cycles, essential for achieving a long cycle life.
A range of materials were prepared via hydrothermal carbonisation of various biomass precursors followed by further heat treatment; by tuning the carbon source, the nature and amount of dopant, the templating agent and the treatment temperature, carbon anodes with varying degrees of graphitisation and tailored pore size, wall thickness and heteroatom functionalities were obtained. The pore structure, particle size, nature of defects and degree of doping were found to have a significant effect on the storage capacity and cycleability of the batteries. The ability to tailor these hierarchical nanostructures therefore makes this process a promising route to achieving new electrode materials.
Heather Au graduated with a MSci in Natural Sciences (Chemistry) from the University of Cambridge in 2011. She was awarded a PhD from Imperial College London on the ‘Development of Grafting Strategies for the Polymer Functionalization of Graphene’ (2017). After completing a postdoc at Imperial College, investigating grafting mechanisms on nanocarbons (2017), she moved to Queen Mary University of London in 2018 and then returned to Imperial College under the supervision of Prof. Magda Titirici, to work on the development of hydrothermal carbon materials as anodes for sodium-ion batteries. Her research focuses on understanding the fundamental mechanisms of sodium storage within hard carbons in order to develop materials with tailored hierarchical nanostructures and improved capacity, for the advancement of sodium-ion technology.