On the Substitution of Aluminium for Copper Conductors in Battery Systems

Abstract

Aluminium’s electrical conductance per-unit mass and per-unit cost is unequalled. These are two desirable properties in a world undergoing widespread electrification. Electricity generation, transmission and utilisation is fundamental in transitioning from non-renewable energy sources and is placing greater demand for low-cost electrical conductors.

Alas, aluminium’s properties are not all favourable to electrical applications, so copper has risen as the dominant conductor material in all but high-voltage long-distance power transmission. Successfully developing aluminium conductors in new applications requires overcoming several challenges, from technical limitations in material properties and manufacturing processes, to programmatic obstacles in development scope and organisation.

This thesis explores the implementation of aluminium conductors in battery system applications. The thesis starts from a broad perspective of material substitution innovation before focusing down on specific technical bottlenecks. The thesis includes analysis of literature, interviews with experienced project managers, reliability testing of design solutions and evaluation of a new manufacturing process. The contributions presented include: a framework for categorising material substitution product development barriers, a test methodology for comparison of detachable aluminium contacts in battery system applications, reliability evidence for specific detachable aluminium contact configurations, a new metric for evaluating the electrical resistance of bimetallic welds and the first electrical assessment of a novel bimetallic joining process. In doing so the thesis supports the development of aluminium conductors and the substitution from copper conductors.