Mgr. Jan Zemen, Ph.D.

Lithium-ion batteries with Si-rich anode have been widely studied recently due to their higher energy density compared to standard Li-ion batteries with graphite anode. However, the volume-expansion during lithiation, low electrical conductivity, and large Li-concentration gradients have prevented broad adoption of Si-anodes so far. The mitigation strategies currently under investigation include the use of micro and nano-structured electrodes or doping of silicon with other elements. This work will focus on degradation processes in Si-rich electrode and their control via micro-structure composition that can lower the internal strain and homogenise the distribution of Li in the electrode. The general aim is to enhance the storage capacity and the lifespan of the battery while adding only environmentally friendly and abundant materials. The experimental part of the work will track the degradation of commercially available cells with Si-based anode during charge and discharge cycles. The complementary simulation effort will focus on a combined electrochemical and thermomechanical model of a cell with micro-structured electrodes solved using the finite element method. A comparison to measured characteristics will be attempted depending on the availability of data on the internal structure of the measured cells.

Efficient thermal management has become critical in many areas of electrical engineering due to growing demand for increasing output power while reducing system size (high power density). Consequently, the excessive temperature can decrease the performance, shorten the lifespan or lead to device failure. Simulations of heat transfer have provided valuable guidance in design of thermal management systems for battery packs, microelectronic devices, electrical machines, etc. For example, detailed thermal modelling allows for estimation of temperature inside a device based on surface temperature measurement. This thesis is devoted to 3D modeling of thermal phenomena using the finite element method (FEM) as implemented in Comsol Multiphysics. The numerical solution of the model will focus on battery packs (for electric vehicles) or on solder joints in printed circuit boards in order to ensure efficient cooling and higher reliability.

Efficient thermal management has become critical in many areas of electrical engineering due to growing demand for increasing output power while reducing system size (high power density). Consequently, the excessive temperature can decrease the performance, shorten the lifespan or lead to device failure. Simulations of heat transfer have provided valuable guidance in design of thermal management systems for battery packs, microelectronic devices, electrical machines, etc. For example, detailed thermal modelling allows for estimation of temperature inside a device based on surface temperature measurement. This thesis is devoted to 3D modeling of thermal phenomena using the finite element method (FEM) as implemented in Comsol Multiphysics. The numerical solution of the model will focus on battery packs (for electric vehicles) or on solder joints in printed circuit boards in order to ensure efficient cooling and higher reliability.

Efficient thermal management has become critical in many areas of electrical engineering due to growing demand for increasing output power while reducing system size (high power density). Consequently, the excessive temperature can decrease the performance, shorten the lifespan or lead to device failure. Simulations of heat transfer have provided valuable guidance in design of thermal management systems for battery packs, microelectronic devices, electrical machines, etc. For example, detailed thermal modelling allows for estimation of temperature inside a device based on surface temperature measurement. This thesis is devoted to 3D modeling of thermal phenomena using the finite element method (FEM) as implemented in Comsol Multiphysics. The numerical solution of the model will focus on battery packs (for electric vehicles) or on solder joints in printed circuit boards in order to ensure efficient cooling and higher reliability.

Efficient thermal management has become critical in many areas of electrical engineering due to growing demand for increasing output power while reducing system size (high power density). Consequently, the excessive temperature can decrease the performance, shorten the lifespan or lead to device failure. Simulations of heat transfer have provided valuable guidance in design of thermal management systems for battery packs, microelectronic devices, electrical machines, etc. For example, detailed thermal modelling allows for estimation of temperature inside a device based on surface temperature measurement. This thesis is devoted to 3D modeling of thermal phenomena using the finite element method (FEM) as implemented in Comsol Multiphysics. The numerical solution of the model will focus on battery packs (for electric vehicles) or on solder joints in printed circuit boards in order to ensure efficient cooling and higher reliability.

Efficient thermal management has become critical in many areas of electrical engineering due to growing demand for increasing output power while reducing system size (high power density). Consequently, the excessive temperature can decrease the performance, shorten the lifespan or lead to device failure. Simulations of heat transfer have provided valuable guidance in design of thermal management systems for battery packs, microelectronic devices, electrical machines, etc. For example, detailed thermal modelling allows for estimation of temperature inside a device based on surface temperature measurement. This thesis is devoted to 3D modeling of thermal phenomena using the finite element method (FEM) as implemented in Comsol Multiphysics. The numerical solution of the model will focus on battery packs (for electric vehicles) or on solder joints in printed circuit boards in order to ensure efficient cooling and higher reliability.

Efficient thermal management has become critical in many areas of electrical engineering due to growing demand for increasing output power while reducing system size (high power density). Consequently, the excessive temperature can decrease the performance, shorten the lifespan or lead to device failure. Simulations of heat transfer have provided valuable guidance in design of thermal management systems for battery packs, microelectronic devices, electrical machines, etc. For example, detailed thermal modelling allows for estimation of temperature inside a device based on surface temperature measurement. This thesis is devoted to 3D modeling of thermal phenomena using the finite element method (FEM) as implemented in Comsol Multiphysics. The numerical solution of the model will focus on battery packs (for electric vehicles) or on solder joints in printed circuit boards in order to ensure efficient cooling and higher reliability.

Efficient thermal management has become critical in many areas of electrical engineering due to growing demand for increasing output power while reducing system size (high power density). Consequently, the excessive temperature can decrease the performance, shorten the lifespan or lead to device failure. Simulations of heat transfer have provided valuable guidance in design of thermal management systems for battery packs, microelectronic devices, electrical machines, etc. For example, detailed thermal modelling allows for estimation of temperature inside a device based on surface temperature measurement. This thesis is devoted to 3D modeling of thermal phenomena using the finite element method (FEM) as implemented in Comsol Multiphysics. The numerical solution of the model will focus on battery packs (for electric vehicles) or on solder joints in printed circuit boards in order to ensure efficient cooling and higher reliability.