# Combined Experimental and Numerical Modelling of the Electrical Behaviour of Laser-Soldered Steel Sheets

## TL;DR

This paper studies how laser-soldered joints in electric vehicle batteries affect electrical resistance and how to minimize resistive losses.

## Contribution

The study introduces a combined experimental and numerical approach to analyze electrical resistance in laser-soldered steel joints.

## Key findings

- Electrical resistance measurements revealed two distinct regimes depending on proximity to the joint.
- Filler material thickness and void distribution significantly influence joint resistance.
- Finite element modeling helps assess resistance changes based on probe distance.

## Abstract

The electric vehicle (EV) industry challenges battery joining technologies by requiring higher energy density both by mass and volume. Improving the energy density via new battery chemistry would be the holy grail but is seriously hindered and progresses slowly. In the meantime, alternative ways, such as implementing more efficient cell packaging by minimising the electrical resistance of joints, are of primary focus. In this paper, we discuss the challenges associated with the electrical characterisation of laser-soldered joints in general, and the minimisation of their resistive losses, in particular. In order to assess the impact of joint resistance on the overall resistance of the sample, the alteration in resistance was monitored as a function of voltage probe distance and modelled by finite element simulation. The experimental measurements showed two different regimes: one far from the joint area and another in its vicinity and within the joint cross-section. The presented results confirm the importance of the thickness of the filler material, the effective and total soldered area, and the area and position of the voids within the total soldered area in determining the electrical resistance of joints.