Innovative EV bus bars (EVBus)

This project aims to establish the feasibility of developing a process that STL can use to manufacture multi-material connectors for both the electrification and power supply markets. Currently these materials or connectors are not available from any UK source and it is doubtful if they are available from any European producer at the sizes and volumes STL hopes to make.

In the ZEV sector, material circa 2mm thick is required and this technique could also allow for different thicknesses to be developed. Aluminium is considerably lighter than copper and sufficiently conductive for major parts of the circuit. Copper generally is needed for cell battery terminations but not for bulk current carrying. EVs have up 7000 cells per unit, the halving of the number of welds needed by the use of pre-bonded material would give considerable reliability and cost benefits when considering the alternatives. Laser welding and wire bonding are used in the EV sector and known to have a number of constraints including poor reliability, the less joints there are the more reliable the product, and the lighter the better.

As far as is known this technique is not practiced by any competitor in this specific field. Variations of the technique are known of in the USA and Europe but this proposal of integral bonding and further processing within one facility is believed to be unique. TWI have some experience in this field but have not yet bonded aluminium to copper and are not the producer of end products. If feasibility can be proven and that a real market exists then STL will be able to invest in facilities and development of a more hygienic industrial scale process.

STL has actual business within the ZEV sector with a customer using stamped mono-metal busbars for a hypercar project and serious interest from others within the startup and prototype market. From there leverage can be used to address the market for mainstream applications within Europe.