Influence of interconnect resistances on parallel-connected LiFePO4 cells performance

EasyChair Preprint no. 1581

Abstract

The battery module of parallel-connected lithium-ion cells is extensively applied in electric vehicles to satisfy the capacity and power capability. However, the performance of the module is influenced by the interconnect resistances and the position of its current collector. An equivalent circuit simulation model is developed and validated by pulse discharge tests. Based on the model, a module of five cells connected in parallel is established, including interconnect resistances. Then the effect of interconnect resistances and different positions of module current collector in parallel-connected cells is tested and discussed by the simulation. Results indicate that the interconnect resistances lead to inhomogeneous currents, and the cell directly connected to the module current collector appears the highest current. That is, the farther the cell is away from the module current collector, the lower current is. The cause are clarified from an angle of the currents through interconnect resistances. Therefore, in order to prolong the module lifetime, the interconnect resistance should be as small as possible, and the module current collector should not be connected with the edge single cell.

Keyphrases: current collector, equivalent circuit model, interconnect resistance, LiFePO4 battery, parallel-connected cells

@Booklet{EasyChair:1581,
  author = {Long Chang and Bin Duan and Peng Li and Kang Zhang and Chenghui Zhang and Linjing Xiao},
  title = {Influence of interconnect resistances on parallel-connected LiFePO4 cells performance},
  howpublished = {EasyChair Preprint no. 1581},

  year = {EasyChair, 2019}}