Hierarchical Nanostructures for Energy Applications

The focus of this work is the application of novel hierarchical architectural nanomaterials in electrode materials designed for Li+, Na+, K+ and, potentially, other multivalent ions. The project will establish novel chemical methods for the encapsulation of metallic materials within carbon nanotubes, their characterisation, and application into targeted energy storage technologies. Such hierarchical materials have been found to possess desirable thermal properties and suitable nanostructures to accommodate the demands for electrochemical applications. The Nanomaterials by Design research group have developed compelling bulk scale synthesis routes for carbon nanotubes, facilitating their integration into coin and pouch cell batteries with our collaborator at Imperial College London.

Emphasis will be placed on the synthesis of graphitic nanomaterials developed with low cost, environmental saving, and large-scale production appropriate. Proficient and suitable materials will escalate from coin cells to pouch cells to evaluate manufacturing strategies/scalability. State-of-the-art chemical vapor deposition synthesis techniques in conjunction with in situ monitoring technologies allow us to engineer the metallic filling composition and morphology of carbon nanotube to tune physical and functional properties. Other synthetic techniques include electrolysis in molten salts of the desired metallic filling and vapor filling of selected material. Particular synthesis methods will enhance mechanical attributes of certain nanomaterials, allowing multi-functional carbon nanotubes to carry mechanical loads whilst remaining electrochemically active, appropriate for progressive structural battery applications.

Transmission electron microscopy will be utilised alongside scanning electron microscopy to gauge the degree of filling and morphology of the filled nanotubes. These techniques will be combined with energy-dispersive X-ray spectroscopy and Raman spectroscopy to obtain local compositional data on the filling. Electrochemical characterisation methodologies include; voltammetry, impendence spectroscopy, and galvanic cycling. Coupled electrochemical characterisation, mechanical testing methods or analytical techniques, such as, spectroscopy, imaging, or diffraction while in situ or in operando electrochemical cycling is crucial to gain insight into material function and chemistry suitability, often providing electrochemical, structural, or spectroscopic analysis which can be directly correlated to performance. Ultimately providing for a feedback loop to access suitability and allow for modification of synthesis or encapsulated chemistry.

The work will be conducted in collaboration with the internationally leading experts in the fields of nanomaterials and electrochemical characterisation respectively. The research group has a range of extensive industrial collaborators and implementation of these materials will be applied into battery technologies. Specific characterisation techniques will be conducted in collaboration with the Henry Royce Institute. Traditionally, the students of the nanomaterials by Design research group re encouraged to engage with academic collaborators as well as industry partners wherever possible.

This project falls within the EPSRC Energy, Engineering, Manufacturing the future, Physical Sciences research areas.