Dr Jiawei Hu

All-solid-state lithium batteries (ASSLBs) are a promising next generation energy storage technology comparing to conventional lithium-ion batteries (LIBs). Although ASSLBs have high thermal stability, thermal degradation and thermal runaway can still occur. The thermal characteristics of the cathode of ASSLBs play a crucial role in maintaining the stability of the interface with the electrolyte. It is important to understand the thermal characteristics of ASSLBs, which is highly associated with specific microstructure geometrics of composite cathodes. Here, this paper presents a 3D lattice Boltzmann heat conduction model to simulate the effective thermal conductivity (ETC) of the multiphase solid-state cathodes, which is composed of active material LCO (LiCoO2) and solid electrolyte LLZO (Li7La3Zr2O12), generated using the discrete element method (DEM) with different porosities, volumetric ratios, particle size ratios, and various composite tortuosities. The findings indicate that porosity, volumetric fraction, and particle size all exert the decisive factor on ETC. Tortuosity emerges as a non-negligible factor influencing thermal conductivity, highlighting the importance of microstructural optimization. •LBM modelling of heat conduction in cathode microstructures of ASSLBs generated using DEM.•An equivalent packed particles heat conduction experiment for model validation.•Porosity and component volume fraction dominantly influence the heat conduction in cathodes.•Particle size and tortuosity are intertwined and have non-negligible effect on heat conduction.

[Display omitted] •Friction-induced heat generation and heat transfer models are developed.•Thermal behaviours of particles and walls are experimentally and numerically analysed.•Effects of rotation speed on temperature rises on both particles and walls are examined. In many granular material handling processes, heat generation, and subsequent temperature rise, due to contacts between particles and surfaces is common. Aiming to explore this phenomenon, friction-induced heat generation and heat transfer models are developed and implemented into a Discrete Element Method (DEM) in this paper. The DEM models are validated qualitatively for the temperature distribution pattern and quantitatively for the evolution of particle temperature rise using data obtained experimentally. Moreover, the temperature distribution of the drum end plates obtained in the simulations shows the same annulus pattern observed in experiments. It is also found that increasing the rotation speed of the drum leads to an increase in the annular heated region of drum and in the net heat that particles obtain. In addition, a higher rotation speed leads to higher absolute fluctuations and lower relative variability of particle temperature.