A novel battery/ ultracapacitor hybrid energy storage system analysis based on physics-based lithium-ion battery modeling

A hybrid energy storage system topology which combines battery and ultracapacitor at the cell level is proposed. In each hybrid cell, lithium-ion cell and ultracapacitor cell are connected through a bi-directional converter for power split. This configuration provides more flexible control capability. In order to observe the internal state and chemical processes of the battery, the single particle (SP) model which includes SEI growth model is applied to lithium-ion cell modeling. The performance of hybrid cell and benefits on aging mechanisms are discussed in different driving cycle tests.