Electrical-thermal modeling and electrical design optimization of fuses in a nickel bus-plate for a Li-ion battery pack

Abstract

This paper presents a two-dimensional thermal-electrical coupled steady-state physics-based finite-element model developed to analyze Nickel 201 (Ni201) bus-plates for a novel 134P battery pack design, where a 1.4C current was applied per cell. Two modeling approaches were used: one with an out-of-plane current density boundary condition inserted in the charge conservation equation and a second one with a constant voltage boundary condition calculated at each battery tab. Both positive and negative-bus plate designs were analyzed. Electric resistance measurements were used to validate the model and the two modeling approaches. This study demonstrated that a nickel bus plate design can be optimized, without the addition of extra material or substantive geometry changes, by clocking the fuses and weld tab connections towards the direction of the closest terminal connection point. The resulting geometry, mimicking a sunflower formation, can reduce the internal resistance of the bus plate by at least 15 %, regardless of the modeling approach used.