High pressure and Li-ion batteries
Compressibility in zero/low thermal expansion materials
Thermal expansion/contraction of materials can be a significant challenge in microscopic applications such as high precision instruments as well as a problem in large-scale applications like jet engines and buildings. These expansion coefficients need to be known and carefully monitored. Alternatively materials that exhibit low or zero thermal expansion over a wide range of temperatures can be developed. Our team has recently worked on one such material. In addition, to the “zero” thermal expansion we have investigated the materials’ response to pressure. The intention is to design and make an extremely stable material, stable in terms of volume and shape as a function of both temperature and pressure. This project focuses on the pressure aspect, to evaluate the pressure induced changes, compressibility, bulk modulus and phase transitions of low or zero thermal expansion materials. The student will systematically work through a range of materials, exploring the pressure-temperature phase diagram and may at the end of the project develop a low thermal and pressure stable material.
The role of pressure in solid state batteries
Lithium-ion batteries are ubiquitous in society finding use in mobile electronics, electric vehicles and grid-scale energy storage. As electrification of the world’s transportation fleet continues these batteries will be more and more prevalent in society. One of the challenges of vehicle-based applications is safety, designing and using an inherently safe battery would further accelerate uptake. Solid state batteries are inherently safe as many of the thermal runaway mechanisms are either non-existent or do not occur in such batteries. Furthermore, use of an appropriate anode, Li metal, may mean a more energy dense battery. In solid state batteries, conductivity and interfacial resistance play a dramatic role in performance. This project is specifically targeting the role of applied pressure on a solid state battery (or part of such a battery). The physiochemical and electrochemical properties of solid state batteries will be examined as a function of pressure. Various compositions of electrodes and electrolytes will be examined. The ultimate goal would be to thorough atomic-level understanding of the role of pressure on device function.
Biomass carbon derived anodes for durable Li-ion batteries
Energy storage is one of the key challenges in the energy transition from non-renewable to renewable sources. The erratic nature of solar or wind energy conversion is an issue, especially for local automotive production. Another challenge is the next generation of electric vehicles that require high capacity storage and short charging time. One solution is the Li-ion battery, which is easy to use, partially recyclable and could become increasingly cost-effective. However, the current technology based on graphitic electrodes is not yet able to meet the requirements (high capacity and fast charge) and there is a growing demand for Li-ion quality graphite or alternatives. The objective of this research project is to study, by applying pressure, the stability and properties of materials that are of potential interest as a new generation of anodes in batteries, such as fluorinated graphites. To do this, we will replace pristine commercial graphite with biomass carbon derived and carbon-neutral or carbon-negative “green” materials to find market-competitive alternatives to carbon pricing (e.g., carbon tax or emission permits). The student will investigate at ILM, France, the impact of pressure on biomass-derived carbons or recycled carbon materials to design more durable, higher-performance lithium-ion battery anodes and the electrochemical tests will be performed at UNSW, Australia.
Physics, Materials Science, Chemistry