3M has been engaged in the study of alloys (Si, Sn, etc...) as anodes for Li-ion batteries for over 15 years. During this time 3M’s interest in Si-based anode materials has grown from laboratory experiments to MT/mth capability. This talk will give a brief overview of 3M’s active/inactive design concept followed by recent findings relevant to automotive applications.
In a number of studies, Prof. Dahn’s group utilized high precision coulometry to demonstrate that the contribution of graphite anodes to the failure of full cells occurs primarily through a time dependence. Indeed, full cells with graphite anodes have a capacity retention that has a stronger dependence on total cycling time than on cycle number.
In this talk, recent studies at 3M utilizing high precision coulometry on Si-alloys will be presented. Findings detail the balance between time-based and cycle-based fade with Si-alloys. The implications of these findings on automotive applications will be discussed and their consequence in shallow cycling applications will be demonstrated.