Battery life predicted with resistance measurement

University of Michigan engineers have identified internal resistance, measured immediately after cells are made, as a key indicator of how long a battery will last. The measurements can be done in seconds towards the end of the manufacturing process at little to no additional cost.

Lifespan prediction is already possible, but it requires repeated cycling-charging, discharging and recharging to gather data needed to train an algorithm. Similarly, ageing tests can take weeks to months to complete and are restricted to a handful of cells per batch of batteries produced.

The new study published in Joule shows that accurate battery lifetimes can be predicted with the help of one resistance measurement. That resistance can come from the materials used for internal components, or electrochemical factors that affect how well ions move between the battery electrodes. According to U-M, measuring resistance at low levels of charge is key.

"The resistance measurement, at low state of charge, can, in principle, be obtained without any cycling, making the model training process much faster," said Andrew Weng, a doctoral student in mechanical engineering and the study's lead author.