Given by Sreelakshmi Anil Kumar.
The seminar will be held on Tuesday 17 February at 10.00 AM in room 110 ILL 50.
Operando investigation of battery materials, electrodes and solid electrolytes, using Neutron Diffraction.
"All-solid-state batteries (ASSBs) are attracting growing interest due to their potential for improved safety and higher energy density compared to conventional lithium-ion batteries. However, a detailed understanding of their electrochemical cycling mechanisms and the associated structural and interfacial evolutions remains limited.
In this seminar, we will present a neutron diffraction study of a model ASSB system based on the commercial layered oxide cathode LiNi0.6Mn0.2Co0.2O2 (NMC622) combined with a mixed-halide argyrodite solid electrolyte, Li5.4PS4.4BrCl0.6, selected for its high ionic conductivity. Owing to their high penetration depth and sensitivity to light elements such as lithium, neutrons provide a powerful probe for investigating bulk structural changes in operating solid-state batteries.
We optimized the NMC622 | Li5.4PS4.4BrCl0.6 | Li0.5In cell configuration to achieve both reliable electrochemical performance and high-quality neutron powder diffraction data, while accommodating the large sample volumes required for neutron experiments. The resulting 2.5 mm thick ASSB pellet enabled ex situ and operando neutron diffraction studies of the structural evolution of the NMC622 cathode and the stability of the argyrodite electrolyte during cycling at room temperature and at 100 °C.
Additionally, we will introduce a newly developed electrochemical cell, ILLBAT#5, that provides improved pressure control during cycling and is compatible with multiple ILL diffractometers, enabling robust operando neutron diffraction measurements of ASSBs."