Calcium-sulphur batteries

Calcium-sulphur (Ca-S) batteries hold the promise of high energy density batteries, consisting of low-cost, abundant, non-toxic materials, calcium anode and sulphur cathode. The proposed project aims at developing a room-temperature Ca-S battery reaching an energy density of 400 Wh/kg of cell, and very good cyclability and lifetime. Such batteries would be very popular for long driving range EVs, other transport means such as electric and hybrid aircraft, and stationary storage linked to renewables on the grid or microgrids. Ca-S batteries are a pioneering solution to accelerate the net-zero transition, while calcium and sulphur will reduce society dependencies on lithium and other rare critical raw materials, such as cobalt, nickel and magnesium, associated with current Li-ion batteries.

CL’s group have already developed high performance sulphur cathodes, which were tested successfully for lithium-sulphur (Li-S) and sodium-sulphur (Na-S) batteries. The benefit of our novel cathodes lies in limiting the shuttling of polysulphides, which means that our cathodes raise the specific capacity and cyclability of sulphur batteries. The proposed PhD is based mainly on experimental work, employing and refining our novel cathodes, taking into account that the Ca-S battery volumetric expansion is expected to be very similar to that observed in Li-S batteries (half of that in Na-S batteries). Novel developments proposed for this PhD include optimising the cathode host structure, investigations of different liquid electrolytes and additives, as well as anode protection. Our group offers additional infrastructure in terms of in operando UV-vis spectroscopy using the portable UV-vis system in CL’s lab and a unique XPS instrument for composition analysis in depth below the specimen surface providing a composition profile through depth. CL’s group is also providing algorithms for the simulation of charge-discharge of a Ca-S cell, based on a physicochemical model taking into account the pore size distribution of each cell component.

Open to any UK or international candidates. Up to 30% of our UKRI funded studentships can be awarded to candidates paying international rate fees.

Candidates with a BEng or BSc or Master degree in any engineering discipline, physics, chemistry or materials, at a minimum grade as follows: first or upper second-class (2:1) UK degree or equivalent non-UK degree, or a lower-second (2:2) UK degree plus a good UK masters degree - distinction normally required (or equivalent overseas qualification). Also if non-UK, English Language requirements as in Engineering Materials PhD Programme webpage.