Research on Mechanical Effects in Li-Ion Batteries in the Monroe Research Group, Department of Engineering Science, University of Oxford

Management of battery systems is difficult due to the variety of physical processes that occur when a battery is put under an electrical load. These processes produce macroscopic side effects, such as stress/strain and temperature evolution, which originate at the electrode level. The electrochemical-thermal-mechanical phenomena in battery cells are highly coupled in applications such as electric vehicles. Because microscopic effects in battery electrodes can propagate into larger length scales such as the cell and pack levels, there are changes on the outside that can be observed.Using this principle we can measure stress/strain on the outside of the cell by implementing things such as force sensors for stress and displacement sensors for strain. Similar to using an IR camera for thermal measurements, we want to implement a non-contact method of measuring strain. We are developing an experimental set-up that lets us use laser profile scanners to capture 2D strain distributions that arise in response to current input in lithium-ion batteries.