Supervisors

Dr Zhenyu Zhang, Department of Engineering, University of Exeter 

Professor Lianzhou Wang, School of Chemical Engineering, University of Queensland

Additional Supervisors:

Prof. Xiaohong Li, Renewable Energy Group, Department of Engineering, University of Exeter

Dr. Haijiao Lu, Chemical Engineering, University of Queensland

Prof. Karen Hudson-Edwards, Department of Earth and Environment Sciences, University of Exeter

Join a world-leading, cross-continental research team

The University of Exeter and the University of Queensland are seeking exceptional students to join a world-leading, cross-continental research team tackling major challenges facing the world’s population in global sustainability and wellbeing as part of the QUEX Institute. The joint PhD programme provides a fantastic opportunity for the most talented doctoral students to work closely with world-class research groups and benefit from the combined expertise and facilities offered at the two institutions, with a lead supervisor within each university. This prestigious programme provides full tuition fees, stipend, travel funds and research training support grants to the successful applicants.  The studentship provides funding for up to 42 months (3.5 years) for both home and international students.

Eight generous, fully-funded studentships are available for the best applicants, four offered by the University of Exeter and four by the University of Queensland. This select group will spend at least one year at each University and will graduate with a joint degree from the University of Exeter and the University of Queensland.

Find out more about the PhD studentships click here

Successful applicants will have a strong academic background and track record to undertake research projects based in one of the three themes of:  Healthy Living, Global Environmental Futures and Digital Worlds and Disruptive Technologies.

The closing date for applications is mid-day Friday June 28th 2024 (BST), with interview to be w/c 29th July 2024 (tbc). The start date is expected to be Monday January 6th 2025.

Please note that of the eight Exeter led projects advertised, we expect that up to four studentships will be awarded.

Supervisors

Exeter Academic Lead: Dr Zhenyu Zhang

Queensland Academic Lead: Professor Lianzhou Wang

THEME - Mineral Security & Sustainability

Project Description

To successfully achieve net zero by 2050, Lithium-ion batteries will play an essential role in the energy transition and storage, powering consumable devices, electric vehicles, and driving the evolution of renewable energy systems. The rapid advancement of battery technologies has spurred global demand for lithium, a critical mineral. By 2030, battery manufacturers in the UK alone could require approximately 15,000 tonnes of lithium annually (UK Critical Minerals Intelligence Centre, CMIC 2022). Securing a sustainable lithium supply is paramount for the resilience of the battery value chain and the growth of the battery industry. To strengthen mineral supply chains, the UK-Australia Free Trade Agreement (2021) was signed to ensure collaborative sourcing and processing of critical minerals in both countries.

Traditionally, commercial lithium sources, primarily salts, are derived from land resources such as high-grade ores and salt lake brines, employing processes like evaporation, chemical precipitation, solvent extraction, and adsorption/desorption. However, land-based lithium reserves are limited and unevenly distributed geographically, with extraction processes bearing significant environmental impacts. In contrast, the lithium content in the ocean is approximately 5,000 times that of land, yet current methods for extracting lithium from seawater remain negligible. The extraction process from seawater involves enrichment, purification, and recovery through adsorption and dialysis methods, albeit complex and relatively inefficient due to low lithium concentrations (0.1-0.2 ppm) and the presence of competing ions (e.g., Na+, Mg2+, K+).

Electrochemical lithium extraction presents an appealing alternative, enabling the extraction of lithium from low-concentration brine lake water or even seawater without the time-consuming evaporation process. In this method, lithium ions can be driven by an external electric current into electrodes or through lithium-selective membranes. Utilizing a lithium-ion-selective membrane facilitates the electrical propulsion of lithium ions, enabling their transport through the membrane and between different electrolyte systems. This continuous system is easily scalable and can be integrated with renewable energy sources such as wind and solar, facilitating low-cost and decarbonized lithium production.
Through the QUEX PhD project (ELITE), significant research outcomes are anticipated, including the development of membrane materials and innovation in electrochemical processes to achieve effective extraction of lithium from seawater and brine. These techniques will be transitioned into practical mining applications through collaboration between two universities and industry partners. In the meantime, the successful PhD student will benefit from rewarding research experience across material science, electrochemistry, and sustainable energy.

Electrochemical lithium extraction offers an appealing method for extracting lithium from low-concentration brine lake water or seawater, without the need for the time-consuming evaporation process. The basic principle of this system involves two main approaches: (1) driving lithium ions with an external electric current either into an electrode or (2) through a lithium-selective membrane.

For example, TiO2-coated LiFePO4 electrode material combined with a pulse electrochemical method was used to adsorb lithium ions from seawater (Joule 2020, 4, 1459.). However, the adsorption suffers from slow kinetics and material degradation by competing ions. The alternative method employs a lithium-ion selective membrane, allowing only lithium ions to be electrically mobilized across it, while other cations are blocked due to crystal mismatch, remaining in the original electrolyte. Typically, the membrane consists of a lithium ion-conducting material, similar to those used as solid electrolytes in all-solid-state lithium-ion batteries. For example, NASICON-type (Li1+xAlyGe2-y(PO4)3, LAGP) (Joule 2018, 2, 1648.) and glass-type (Li0.33La0.56TiO3, LLTO) (Energy Environ. Sci. 2021, 14, 3152.) lithium-ion conductors have been used in this system. As shown in the figure, by continuously introducing seawater or brine water on the anode side, lithium-ion concentration can be increased on the cathode side. Lithium salt precipitation in the cathode side aqueous electrolyte or lithium metal deposition on cathode with organic electrolyte can be achieved. Simultaneously, byproduct such as Cl2/O2 and H2 gases are generated on the electrodes. Although this design has been demonstrated in several publications, significant challenges persist, such as the low selectivity ratio of lithium ions, slow kinetics for the lithium transport, low lithium generation rate and low energy efficiency.

In this project, the main objectives include:
(1)   Develop novel lithium selective membrane, based on the advanced solid state electrolyte materials for all-solid-state lithium-ion battery. Using surface coating materials to protect and improve the ion selectivity, conductivity, and long-term stability in different electrolyte.
(2)   Design new electrolyte systems for the electrochemical process, such as catalyst materials on the anode, using of anion exchange membrane for the anode protection electrolyte, and electrolyte of cathode side, to optimize the efficiency of lithium production.
(3)   Integrate the system with renewable energy sources to achieve sustainable lithium extraction. Demonstrate the practical application of the according to the industry needs.

From the Exeter side, Dr Zhenyu Zhang is an expert in the material degradation study of electrochemical systems, especially in lithium-ion battery and solid-state electrolytes; Prof. Xiaohong Li's team provides specialised knowledge in energy conversion systems such as hydrogen production from sea water and membrane-free flow batteries. From the Queensland side, Prof. Lianzhou Wang and Dr. Haijiao Lu offer expertise in materials synthesis and characterisation, and developing catalysts electrochemical reactions. The objectives 1 are expected to be progressed at Queensland with their abundant resources for catalyst synthesis and performance evaluation, and the objectives 2-3 will be achieved at Exeter with the excellent facilities and infrastructures for system development and large-scale demonstration. The collaboration between the teams will leverage the combined knowledge and facilities to ELITE."

Entry requirements

Applicants should be highly motivated and have, or expect to obtain, either a first or upper-second class BA or BSc (or equivalent) in a relevant discipline.

If English is not your first language you will need to meet the English language requirements and provide proof of proficiency. Click here for more information and a list of acceptable alternative tests.

How to apply

Apply now

Owing to essential maintenance, SRS will be unavailable between 17:00 BST on Thursday 27th June and 09:00 BST Monday 1st July 2024, which means you are unable to submit an applications during this time.
The application deadline will therefore be extended until 12:00 BST on Wednesday 3rd July.
Please accept our apologies for any inconvenience caused.

You will be asked to submit some personal details and upload a full CV, supporting statement, academic transcripts and details of two academic referees. Your supporting statement should outline your academic interests, prior research experience and reasons for wishing to undertake this project, with particular reference to the collaborative nature of the partnership with the University of Queensland, and how this will enhance your training and research.

Interview notifications date TBC

Please quote reference 5159 on your application and in any correspondence about this studentship.

Summary