PhD: Investigation of Ripple Current Effects in Batteries


Dr Rohit Bhagat

Project overview

An exciting opportunity to work as part of our Electrochemical Engineering research group at WMG, University of Warwick, linked to projects in energy storage (Zapinamo) and electric vehicles (Jaguar Land Rover), for the duration of your PhD.

Lithium batteries are the favoured contender for transport electrification, and static energy storage for demand management and support of rapid electric vehicle charging. In these applications the battery is connected to a power electronic converter, which means that that current will contain current components related to the switching frequency, typically 10 to 50 kHz. In many cases, such as electric vehicle motors, the load will be a balanced three-phase load so there will be no component at the modulating frequency, although there may be small components related to imperfect phase balance. However, for systems linked to a single phase supply such as domestic energy storage and charging support units, there will be a large ripple current at twice the supply frequency.

There is a need for systematic study in this area, especially as new battery chemistries emerge. Battery pack designers need to understand the effect of ripple currents on battery life and performance to be able to set limits to avoid undue degradation. Knowledge of those limits will enable the designers of power electronics to ensure that the limits are adhered to yet avoiding unnecessary expensive and bulky filtering circuits. The project will involve both practical work (testing cell response to various ripple current regimes), modelling (developing physics-based models to predict battery behaviour) and model verification.

The work will be linked to projects in energy storage (Zapinamo) and electric vehicles (Jaguar Land Rover).

Apply here